trunk/Master/texmf-dist/metapost

git-svn-id: svn://tug.org/texlive/trunk@104 c570f23f-e606-0410-a88d-b1316a301751

18 files changed, 8560 insertions, 0 deletions

diff --git a/Master/texmf-dist/metapost/context/base/metafun.mp b/Master/texmf-dist/metapost/context/base/metafun.mp
new file mode 100644
index 00000000000..5071013c5f8
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/metafun.mp
@@ -0,0 +1,63 @@
+%D \module
+%D   [       file=metafun.mp,
+%D        version=2000.07.15,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=format generation file,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+%D When generating many graphics at runtime, it can save run
+%D time to use a format file. We could have named this file
+%D \type {context}, but this is error prone, because it forces
+%D to use the progname \type {mpost} or \type {context}
+%D explicitly, depending on the needs. When using the format,
+%D a mismatch in the memory specification of \type {mpost} or
+%D \type {context} (the \TEX\ one) could lead to lost strings
+%D (and as a result in buggy boundingbox and special
+%D handling). By using the name \type {metatex} we make sure
+%D that we use (unless overloaded) the settings of \type
+%D {mpost}.
+
+if unknown ahangle :
+  input plain.mp ; % John Hobby's file
+else :
+  let dump = relax ;
+fi ;
+
+input mp-tool.mp ;
+input mp-spec.mp ;
+input mp-core.mp ;
+input mp-page.mp ;
+input mp-text.mp ;
+input mp-shap.mp ;
+input mp-butt.mp ;
+input mp-char.mp ;
+input mp-step.mp ;
+input mp-grph.mp ;
+input mp-figs.mp ;
+
+%     mp-form.mp ;
+input mp-grid.mp ;
+input mp-func.mp ;
+
+string metafunversion ;
+
+metafunversion = "metafun"                       & " " &
+                 decimal year                    & "-" &
+                 decimal month                   & "-" &
+                 decimal day                     & " " &
+                 decimal (time div 60)           & ":" &
+                 decimal (time-(time div 60)*60) ;
+
+let normalend = end ;
+
+def end =
+  ; message "" ; message metafunversion ; message "" ; normalend ;
+enddef ;
+
+dump ; endinput .
diff --git a/Master/texmf-dist/metapost/context/base/mp-back.mp b/Master/texmf-dist/metapost/context/base/mp-back.mp
new file mode 100644
index 00000000000..99e88554b62
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-back.mp
@@ -0,0 +1,206 @@
+%D \module
+%D   [       file=mp-back.mp,
+%D        version=2000.05.31, 
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=backgrounds,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for 
+%C details. 
+
+if unknown context_tool :    input mp-tool ; fi ; 
+if   known context_back : endinput         ; fi ; 
+
+boolean context_back ; context_back := true ; 
+
+def some_hash ( expr hash_width     , 
+                     hash_height    ,    
+                     hash_linewidth , 
+                     hash_linecolor , 
+                     hash_angle     , 
+                     hash_gap       ) = 
+
+  stripe_gap := hash_gap ;
+  stripe_angle := hash_angle ;
+  drawoptions (withpen pencircle scaled hash_linewidth 
+               withcolor hash_linecolor) ;
+  path p ; p := unitsquare xscaled hash_width yscaled hash_height ;
+  stripe_path_a () (draw) p ;  % next we move it all to quadrant 1
+  currentpicture := currentpicture shifted urcorner currentpicture ; 
+
+enddef ; 
+
+def some_double_back (expr back_type        , 
+                           back_width       ,
+                           back_height      ,
+                           back_delta       , 
+                           back_linewidth   , 
+                           back_linecolor   , 
+                           back_fillcolor   , 
+                           back_topcolor    , 
+                           back_bottomcolor ,
+                           back_leftcolor   , 
+                           back_rightcolor  ) = 
+
+  numeric ww ; ww := back_width  ; 
+  numeric hh ; hh := back_height ; 
+  numeric dd ; dd := back_delta  ; 
+
+  color back_nillcolor ; back_nillcolor := back_topcolor ; 
+
+  path p ; p := fullsquare xscaled  ww      yscaled  hh      ;  
+  path q ; q := fullsquare xscaled (ww-2dd) yscaled (hh-2dd) ; 
+  path r ; r := llcorner p -- 
+                lrcorner p shifted (-3dd,0) .. controls lrcorner p .. 
+                lrcorner p shifted (0, 3dd) -- 
+                urcorner p shifted (0,-3dd) .. controls urcorner p .. 
+                urcorner p shifted (-3dd,0) --
+                ulcorner p -- cycle ;
+  path s ; s := r xscaled ((ww-2dd)/ww) yscaled ((hh-2dd)/hh) ;
+  path t ; t := llcorner p -- 
+                lrcorner p -- 
+                urcorner p shifted (0,-3dd) .. controls urcorner p .. 
+                urcorner p shifted (-3dd,0) -- 
+                ulcorner p shifted ( 3dd,0) .. controls ulcorner p .. 
+                ulcorner p shifted (0,-3dd) --
+                llcorner p -- cycle ;
+  path u ; u := t xscaled ((ww-2dd)/ww) yscaled ((hh-2dd)/hh) ;
+  path v ; v := llcorner p shifted ( 3dd,0) -- 
+                lrcorner p shifted (-3dd,0) .. controls lrcorner p .. 
+                lrcorner p shifted (0, 3dd) -- 
+                urcorner p shifted (0,-3dd) .. controls urcorner p .. 
+                urcorner p shifted (-3dd,0) --
+                ulcorner p shifted ( 3dd,0) .. controls ulcorner p .. 
+                ulcorner p shifted (0,-3dd) ..
+                llcorner p shifted (0, 3dd) .. controls llcorner p .. cycle ; % {down}  .. cycle ;
+  path w ; w := t xscaled ((ww-2dd)/ww) yscaled ((hh-2dd)/hh) ;
+  path a ; a := llcorner p -- ulcorner p -- 
+                ulcorner q -- llcorner q -- cycle ;
+  path b ; b := llcorner p -- lrcorner p -- 
+                lrcorner q -- llcorner q -- cycle ;
+  path c ; c := lrcorner p -- urcorner p -- 
+                urcorner q -- lrcorner q -- cycle ;
+  path d ; d := ulcorner p -- urcorner p -- 
+                urcorner q -- ulcorner q -- cycle ;
+  path e ; e := llcorner p -- lrcorner p -- 
+                urcorner p -- urcorner q -- 
+                lrcorner q -- llcorner q -- cycle ;
+  path f ; f := llcorner p -- ulcorner p -- 
+                urcorner p -- urcorner q -- 
+                ulcorner q -- llcorner q -- cycle ;
+
+  linecap := butt ; pickup pencircle scaled back_linewidth ; 
+
+  if back_type=1 : 
+
+    fill p withcolor back_fillcolor   ; 
+    fill a withcolor back_leftcolor   ; 
+    fill b withcolor back_bottomcolor ;  
+    fill c withcolor back_rightcolor  ; 
+    fill d withcolor back_topcolor    ; 
+    draw a withcolor back_linecolor   ; 
+    draw d withcolor back_linecolor   ; 
+    draw b withcolor back_linecolor   ; 
+    draw c withcolor back_linecolor   ; 
+
+  elseif back_type=2 : 
+
+    fill p withcolor back_fillcolor   ; 
+    fill e withcolor back_bottomcolor ; 
+    fill f withcolor back_topcolor    ; 
+    draw e withcolor back_linecolor   ; 
+    draw f withcolor back_linecolor   ; 
+
+  elseif back_type=3 : 
+
+    fill v withcolor back_nillcolor   ; 
+    fill w withcolor back_fillcolor   ; 
+    draw v withcolor back_linecolor   ; 
+    draw w withcolor back_linecolor   ; 
+
+  elseif back_type=4 : 
+
+    fill t withcolor back_nillcolor   ; 
+    fill u withcolor back_fillcolor   ; 
+    draw t withcolor back_linecolor   ; 
+    draw u withcolor back_linecolor   ; 
+
+  elseif back_type=5 : 
+
+    t := t rotatedaround(center t,180) ; 
+    u := u rotatedaround(center u,180) ; 
+
+    fill t withcolor back_nillcolor   ; 
+    fill u withcolor back_fillcolor   ; 
+    draw t withcolor back_linecolor   ; 
+    draw u withcolor back_linecolor   ; 
+
+  elseif back_type=6 : 
+
+    r := r rotatedaround(center r,180) ; 
+    s := s rotatedaround(center s,180) ; 
+
+    fill r withcolor back_nillcolor   ; 
+    fill s withcolor back_fillcolor   ; 
+    draw r withcolor back_linecolor   ; 
+    draw s withcolor back_linecolor   ; 
+
+  elseif back_type=7 : 
+
+    fill r withcolor back_nillcolor   ; 
+    fill s withcolor back_fillcolor   ; 
+    draw r withcolor back_linecolor   ; 
+    draw s withcolor back_linecolor   ; 
+
+fi ; 
+
+enddef ; 
+
+endinput ;
+
+beginfig (1) ; 
+
+some_double_back (1, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, .6white, .7white, .6white)
+
+currentpicture := currentpicture shifted (0,-3cm) ; 
+
+some_double_back (2, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, .6white, white, white)
+
+currentpicture := currentpicture shifted (0,-3cm) ; 
+
+some_double_back (3, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, white, white, white)
+
+currentpicture := currentpicture shifted (0,-3cm) ; 
+
+some_double_back (4, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, white, white, white)
+
+currentpicture := currentpicture shifted (0,-3cm) ; 
+
+some_double_back (5, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, white, white, white)
+
+currentpicture := currentpicture shifted (0,-3cm) ; 
+
+some_double_back (6, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, white, white, white)
+
+currentpicture := currentpicture shifted (0,-3cm) ; 
+
+some_double_back (7, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, white, white, white)
+
+currentpicture := currentpicture shifted (0,-3cm) ; 
+
+some_double_back (8, 4.5cm, 1.5cm, .25cm, 1mm, 
+           .5white, .8white, .7white, white, white, white)
+
+endfig ; 
+
+end .
diff --git a/Master/texmf-dist/metapost/context/base/mp-butt.mp b/Master/texmf-dist/metapost/context/base/mp-butt.mp
new file mode 100644
index 00000000000..cf580211e59
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-butt.mp
@@ -0,0 +1,75 @@
+%D \module
+%D   [       file=mp-butt.mp,
+%D        version=2000.05.31, 
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=buttons,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for 
+%C details. 
+
+if unknown context_tool :    input mp-tool ; fi ; 
+if   known context_butt : endinput         ; fi ; 
+
+boolean context_butt ; context_butt := true ; 
+
+def some_button (expr button_type    , 
+                      button_size    ,
+                      button_linecolor , 
+                      button_fillcolor ) = 
+
+  numeric button_linewidth ; button_linewidth := button_size/10 ;
+
+  drawoptions (withpen pencircle scaled button_linewidth 
+               withcolor button_linecolor) ;
+
+  path p    ; p := unitsquare scaled button_size ;
+  numeric d ; d := button_size ;
+  numeric l ; l := button_linewidth ;
+
+  fill p withcolor button_fillcolor ; draw p ;
+
+  if     button_type=101 : 
+    draw (d-2l,2l)--(2l,.5d)--(d-2l,d-2l)--cycle ;
+  elseif button_type=102 : 
+    draw (2l,2l)--(d-2l,.5d)--(2l,d-2l)--cycle ;
+  elseif button_type=103 : 
+    for i=2l step 2l until d-2l :
+      draw (2l,i)--(2l  ,i) ;
+      draw (4l,i)--(d-2l,i) ;
+    endfor ;
+  elseif button_type=104 : 
+    for i=2l step 2l until d-2l :
+      draw (2l   ,i)--(d/2-l,i) ;
+      draw (d/2+l,i)--(d-2l ,i) ;
+    endfor ;
+  elseif button_type=105 : 
+    fill fullcircle scaled (.2d) shifted (.5d,.7d) ; 
+    fill fullcircle xscaled (.6d) yscaled d shifted (.5d,0) ; 
+    clip currentpicture to p ;
+    draw p ; 
+  elseif button_type=106 :
+    draw (2l,2l)--(d-2l,d-2l) ;
+    draw (d-2l,2l)--(2l,d-2l) ;
+  elseif button_type=107 :
+    p := (3l,d-2l)--(d-3l,d-2l)--(.5d,4l)--cycle ; 
+    fill p ; draw p ; 
+    draw (.5d,2l) ; 
+  elseif button_type=108 : 
+    draw (.5d,2l)--(d-2l,d-2l)--(2l,d-2l)--cycle ; 
+  elseif button_type=109 : 
+    draw (.5d,d-2l)--(d-2l,2l)--(2l,2l)--cycle ; 
+  elseif button_type=110 : 
+    button_linewidth := button_linewidth/2 ;  
+    draw p enlarged (-2l,-l) ;
+    for i=2l step l until d-2l : 
+      draw (3l,i)--(d-3l,i) ; 
+    endfor ; 
+  fi ; 
+
+enddef ; 
+
+endinput ; 
diff --git a/Master/texmf-dist/metapost/context/base/mp-char.mp b/Master/texmf-dist/metapost/context/base/mp-char.mp
new file mode 100644
index 00000000000..cd774d50962
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-char.mp
@@ -0,0 +1,997 @@
+% to be cleaned up, namespace needed ! ! ! ! !
+
+%D \module
+%D   [       file=mp-char.mp,
+%D        version=1998.10.10,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=charts,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if unknown context_shap :    input mp-shap ; fi ;
+if   known context_char : endinput         ; fi ;
+
+boolean context_char ; context_char := true ;
+
+% kan naar elders
+
+current_position := 0 ;
+
+def save_text_position (expr p) =  % beware: clip shift needed
+  current_position := current_position + 1 ;
+  savedata
+    "\MPposition{" & decimal current_position & "}{"
+                   & decimal xpart p          & "}{"
+                   & decimal ypart p          & "}" ;
+enddef ;
+
+%D settings
+
+grid_width   := 60pt ; grid_height  := 40pt ;
+shape_width  := 45pt ; shape_height := 30pt ;
+
+chart_offset :=  2pt ;
+
+color chart_background_color ; chart_background_color := white ;
+
+%D test mode
+
+boolean show_mid_points ; show_mid_points := false ;
+boolean show_con_points ; show_con_points := false ;
+boolean show_all_points ; show_all_points := false ;
+
+%D shapes
+
+color shape_line_color, shape_fill_color ;
+
+shape_line_width := 2pt ;
+shape_line_color := .5white ;
+shape_fill_color := .9white ;
+
+shape_node           :=  0 ;
+shape_action         := 24 ;
+shape_procedure      :=  5 ;
+shape_product        := 12 ;
+shape_decision       := 14 ;
+shape_archive        := 19 ;
+shape_loop           := 35 ;
+shape_wait           :=  6 ;
+shape_subprocedure   := 20 ; shape_sub_procedure   := 20 ;
+shape_singledocument := 32 ; shape_single_document := 32 ;
+shape_multidocument  := 33 ; shape_multi_document  := 33 ;
+shape_right          := 66 ;
+shape_left           := 67 ;
+shape_up             := 68 ;
+shape_down           := 69 ;
+
+% vardef some_shape_path (expr type) == imported from mp-shap
+
+def show_shapes (expr n) =
+
+  begin_chart(n,8,10) ;
+    show_con_points := true ;
+    for i=0 upto 7 :
+      for j=0 upto 9 :
+        new_shape(i+1,j+1,i*10+j);
+      endfor ;
+    endfor ;
+  end_chart ;
+
+enddef ;
+
+%D connections
+
+def new_chart =
+
+  color connection_line_color ;
+
+  connection_line_width  := shape_line_width ;
+  connection_line_color  := .8white ;
+  connection_smooth_size := 5pt ;
+  connection_arrow_size  := 4pt ;
+  connection_dash_size   := 3pt ;
+
+  max_x := 6 ;
+  max_y := 4 ;
+
+  numeric xypoint       ; xypoint := 0 ;
+
+  pair    xypoints []   ;
+
+  boolean xyfree   [][] ;
+  path    xypath   [][] ;
+  numeric xysx     [][] ;
+  numeric xysy     [][] ;
+  color   xyfill   [][] ;
+  color   xydraw   [][] ;
+  numeric xyline   [][] ;
+  boolean xypeep   [][] ;
+
+  numeric cpath         ; cpath := 0 ;
+  path    cpaths    []  ;
+  numeric cline     []  ;
+  color   ccolor    []  ;
+  boolean carrow    []  ;
+  boolean cdash     []  ;
+  boolean ccross    []  ;
+
+  boolean smooth        ; smooth       := true  ;
+  boolean peepshape     ; peepshape    := false ;
+  boolean arrowtip      ; arrowtip     := true  ;
+  boolean dashline      ; dashline     := false ;
+  boolean forcevalid    ; forcevalid   := false ;
+  boolean touchshape    ; touchshape   := false ;
+  boolean showcrossing  ; showcrossing := false ;
+
+  picture dash_pattern ;
+
+  boolean reverse_y ; reverse_y := true ;
+
+enddef ;
+
+new_chart ;
+
+def y_pos (expr y) =
+  if reverse_y : max_y + 1 - y else : y fi
+enddef ;
+
+def initialize_grid (expr maxx, maxy) =
+  begingroup ;
+  save i, j ;
+  max_x := maxx ;
+  max_y := maxy ;
+  dsp_x := 0 ;
+  dsp_y := 0 ;
+  for x=1 upto max_x :
+    for y=1 upto max_y :
+      xyfree [x][y] := true ;
+      xyfill [x][y] := shape_fill_color ;
+      xydraw [x][y] := shape_line_color ;
+      xyline [x][y] := shape_line_width ;
+    endfor ;
+  endfor ;
+  endgroup ;
+enddef ;
+
+def scaled_to_grid =
+  xscaled grid_width yscaled grid_height
+enddef ;
+
+def xy_offset (expr x, y) =
+  (x+.5,y+.5)
+enddef ;
+
+def draw_shape (expr x, yy, p, sx, sy) =
+  begingroup ;
+  save y ;
+  y := y_pos(yy) ;
+  xypath [x][y] := (p xscaled sx yscaled sy) shifted xy_offset(x,y) ;
+  xyfree [x][y] := false ;
+  xysx   [x][y] := sx ;
+  xysy   [x][y] := sy ;
+  xyfill [x][y] := shape_fill_color ;
+  xydraw [x][y] := shape_line_color ;
+  xyline [x][y] := shape_line_width ;
+  xypeep [x][y] := peepshape ;
+  endgroup ;
+enddef ;
+
+vardef i_point (expr x, y, p, t) =
+  begingroup ;
+  save q, ok ;
+  pair q ;
+  boolean ok ;
+  q := xypath[x][y] intersection_point ((p) shifted xy_offset(x,y)) ;
+  ok := true ;
+%  if xpart q < -.5 : ok := false ; q := (-.45,ypart q) fi ;
+%  if xpart q >  .5 : ok := false ; q := ( .45,ypart q) fi ;
+%  if ypart q < -.5 : ok := false ; q := (xpart q,-.45) fi ;
+%  if ypart q >  .5 : ok := false ; q := (xpart q, .45) fi ;
+  if not ok :
+    message (t & " of shape (" & decimal x & "," & decimal y & ") limited") ;
+  fi ;
+  q
+  endgroup
+enddef ;
+
+vardef trimmed (expr x, y, z, t) =
+  if touchshape and t : xyline[x][y]/z else : epsilon fi
+enddef ;
+
+zfactor := 1/3 ;
+
+vardef xy_bottom (expr x, y, z, t) =
+  i_point (x, y, ((0,0)--(0,-2)) shifted (zfactor*z*xysx[x][y],0), "bottom")
+  shifted(0,-trimmed(x,y,grid_height,t))
+enddef ;
+
+vardef xy_top (expr x, y, z, t) =
+  i_point (x, y, ((0,0)--(0,2))  shifted (zfactor*z*xysx[x][y],0), "top")
+  shifted(0,trimmed(x,y,grid_height,t))
+enddef ;
+
+vardef xy_left (expr x, y, z, t) =
+  i_point (x, y, ((0,0)--(-2,0)) shifted (0,zfactor*z*xysy[x][y]), "left")
+  shifted(-trimmed(x,y,grid_width,t),0)
+enddef ;
+
+vardef xy_right (expr x, y, z, t) =
+  i_point (x, y, ((0,0)--(2,0))  shifted (0,zfactor*z*xysy[x][y]), "right")
+  shifted(trimmed(x,y,grid_width,t),0)
+enddef ;
+
+def flush_shapes =
+  for x=1 upto max_x :
+    for y=1 upto max_y :
+      flush_shape (x, y) ;
+    endfor ;
+  endfor ;
+enddef ;
+
+def draw_connection_point (expr x, y, z) =
+  pickup pencircle scaled if (z=0): 2 fi xyline[x][y] ;
+  drawdot xy_bottom(x,y,z,false) scaled_to_grid withcolor (1,0,0) ;
+  drawdot xy_top   (x,y,z,false) scaled_to_grid withcolor (0,1,0) ;
+  drawdot xy_left  (x,y,z,false) scaled_to_grid withcolor (0,0,1) ;
+  drawdot xy_right (x,y,z,false) scaled_to_grid withcolor (1,1,0) ;
+enddef ;
+
+def flush_shape (expr x, yy) =
+  begingroup ;
+  save y ;
+  y := y_pos(yy) ;
+  if not xyfree[x][y] :
+    pickup pencircle scaled xyline[x][y] ;
+    if xypeep[x][y] :
+      fill (xypath[x][y] peepholed (unitsquare shifted (x,y)))
+        scaled_to_grid withpen pencircle scaled 0
+        withcolor chart_background_color ;
+    else :
+      fill xypath[x][y] scaled_to_grid withcolor xyfill[x][y] ;
+    fi ;
+    draw xypath[x][y] scaled_to_grid withcolor xydraw[x][y] ;
+    if show_con_points or show_all_points :
+      draw_connection_point (x, y, 0) ;
+    fi ;
+    if show_all_points :
+      for i=-1 upto 1 :
+        draw_connection_point (x, y, i) ;
+      endfor ;
+    fi ;
+  fi ;
+  endgroup ;
+enddef ;
+
+vardef points_initialized (expr xfrom, yfrom, xto, yto, n) =
+  if not xyfree[xfrom][yfrom] and not xyfree[xto][yto] :
+    xypoint := n ; true
+  else :
+    xypoint := 0 ; false
+  fi
+enddef ;
+
+def collapse_points = % this is now an mp-tool macro
+  % remove redundant points
+  n := 1 ;
+  for i=2 upto xypoint:
+    if not (xypoints[i]=xypoints[n]) :
+      n := n + 1 ;
+      xypoints[n] := xypoints[i]
+    fi ;
+  endfor ;
+  xypoint := n ;
+  % make straight lines
+  if xypoints[2]=xypoints[xypoint-1] :
+    xypoints[3] := xypoints[xypoint] ;
+    xypoint := 3 ;
+  fi ;
+enddef ;
+
+vardef smooth_connection (expr a,b) =
+  sx := connection_smooth_size/grid_width ;
+  sy := connection_smooth_size/grid_height ;
+  if ypart a = ypart b :
+    a shifted (if xpart a >= xpart b : - fi sx,0)
+% a shifted (sx*xpart unitvector(b-a),0)
+  else :
+    a shifted (0,if ypart a >= ypart b : - fi sy)
+% a shifted (0,sy*ypart unitvector(b-a))
+  fi
+enddef ;
+
+vardef trim_points =
+  begingroup
+  save p, a, b, d, i ; path p ; pair d ;
+  p := for i=1 upto xypoint-1 : xypoints[i]-- endfor xypoints[xypoint] ;
+  if touchshape :
+    a := shape_line_width/grid_width ;
+    b := shape_line_width/grid_height ;
+  else :
+    a := epsilon ;
+    b := epsilon ;
+  fi ;
+  d := direction infinity of p ;
+  xypoints[xypoint] := xypoints[xypoint] shifted
+  if     xpart d < 0 : (+a,0) ;
+  elseif xpart d > 0 : (-a,0) ;
+  elseif ypart d < 0 : (0,+b) ;
+  elseif ypart d > 0 : (0,-b) ;
+  else               : origin ;
+  fi ;
+  d := direction 0 of p ;
+  xypoints[1] := xypoints[1] shifted
+  if     xpart d < 0 : (-a,0) ;
+  elseif xpart d > 0 : (+a,0) ;
+  elseif ypart d < 0 : (0,-b) ;
+  elseif ypart d > 0 : (0,+b) ;
+  else               : origin ;
+  fi ;
+  endgroup
+enddef ;
+
+vardef trim_points = enddef ;
+
+vardef connection_path =
+  if reverse_connection : reverse fi (xypoints[1]--
+  for i=2 upto xypoint-1 :
+    if smooth :
+      smooth_connection(xypoints[i],xypoints[i-1])  ..
+      controls xypoints[i] and xypoints[i] ..
+      smooth_connection(xypoints[i],xypoints[i+1])  --
+    else :
+      xypoints[i]--
+    fi
+  endfor
+  xypoints[xypoint])
+enddef ;
+
+% vardef connection_path =
+%   sx := connection_smooth_size/grid_width ;
+%   sy := connection_smooth_size/grid_height ;
+%   if reverse_connection : reverse fi
+%   (for i=1 upto xypoint-1 : xypoints[i] -- endfor xypoints[xypoint])
+%   if smooth : cornered max(sx,sy) fi
+% enddef ;
+%
+% primarydef p cornered c =
+%   if cycle p :
+%     ((point 0 of p) shifted (c*(unitvector(point 1 of p - point 0 of p))) --
+%      for i=1 upto length(p) :
+%        (point i-1 of p) shifted (c*(unitvector(point i   of p - point i-1 of p))) --
+%        (point i   of p) shifted (c*(unitvector(point i-1 of p - point i   of p))) ..
+%        controls point i of p ..
+%      endfor cycle)
+%   else :
+%     ((point 0 of p) --
+%      for i=1 upto length(p)-1 :
+%        (point i-1 of p) shifted (c*(unitvector(point i   of p - point i-1 of p))) --
+%        (point i   of p) shifted (c*(unitvector(point i-1 of p - point i   of p))) ..
+%        controls point i of p ..
+%      endfor
+%      (point length(p) of p))
+%   fi
+% enddef ;
+
+def draw_connection =
+  if xypoint>0 :
+    collapse_points ;
+    trim_points ;
+    cpath := cpath + 1 ;
+    cpaths[cpath] := connection_path scaled_to_grid ;
+    cline[cpath]  := connection_line_width ;
+    ccolor[cpath] := connection_line_color ;
+    carrow[cpath] := arrowtip ;
+    cdash[cpath]  := dashline ;
+    ccross[cpath] := showcrossing ;
+  else :
+    message("no connection defined") ;
+  fi ;
+  reverse_connection := false ;
+enddef ;
+
+def flush_connections =
+  pair ip ;
+  boolean crossing ;
+  ahlength     := connection_arrow_size ;
+  dash_pattern := dashpattern(on connection_dash_size off connection_dash_size ) ;
+  for i=1 upto cpath :
+    if ccross[i] :
+      crossing := false ;
+      for j=1 upto i :
+       %if not ((point infinity of cpaths[i] = point infinity of cpaths[j]) or
+       %        (point 0        of cpaths[i] = point 0        of cpaths[j])) :
+        if not  (point infinity of cpaths[i] = point infinity of cpaths[j]) :
+          ip := cpaths[i] intersection_point cpaths[j] ;
+          if intersection_found : crossing := true fi ;
+        fi ;
+      endfor ;
+      if crossing :
+        pickup pencircle scaled 2cline[i] ;
+       %draw cpaths[i] withcolor chart_background_color ;
+        path cp ; cp := cpaths[i] ;
+        cp := cp cutbefore point .05 length cp of cp ;
+        cp := cp cutafter  point .95 length cp of cp ;
+        draw cp withcolor chart_background_color ;
+      fi ;
+    fi ;
+    pickup pencircle scaled cline[i] ;
+    if carrow[i] :
+      if cdash[i] :
+        drawarrow cpaths[i] withcolor ccolor[i] dashed dash_pattern ;
+      else :
+        drawarrow cpaths[i] withcolor ccolor[i] ;
+      fi ;
+    else :
+      if cdash[i] :
+        draw cpaths[i] withcolor ccolor[i] dashed dash_pattern ;
+      else :
+        draw cpaths[i] withcolor ccolor[i] ;
+      fi ;
+    fi ;
+    draw_midpoint (i) ;
+  endfor ;
+enddef ;
+
+def draw_midpoint (expr n) =
+  begingroup
+  save p ;
+  pair p ;
+  p := point .5*length(cpaths[n]) of cpaths[n];
+  pickup pencircle scaled 2cline[n] ;
+  save_text_position (p) ;
+  if show_mid_points :
+    drawdot p withcolor .7white ;
+  fi ;
+  endgroup ;
+enddef ;
+
+boolean reverse_connection ; reverse_connection := false ;
+
+vardef up_on_grid (expr n) =
+  (xpart xypoints[n],(ypart xypoints[n]+1) div 1)
+enddef ;
+
+vardef down_on_grid (expr n) =
+  (xpart xypoints[n],(ypart xypoints[n]) div 1)
+enddef ;
+
+vardef left_on_grid (expr n) =
+  ((xpart xypoints[n]) div 1, ypart xypoints[n])
+enddef ;
+
+vardef right_on_grid (expr n) =
+  ((xpart xypoints[n]+1) div 1, ypart xypoints[n])
+enddef ;
+
+vardef x_on_grid (expr n, xfrom, xto, zfrom) =
+  if (xfrom=xto) and not (zfrom=0) :
+    if (zfrom=1) : right_on_grid(2) else : left_on_grid(2) fi
+  elseif xpart xypoints[1] < xpart xypoints[6] :
+    right_on_grid(n)
+  else :
+    left_on_grid(n)
+  fi
+enddef ;
+
+vardef y_on_grid (expr n, yfrom, yto, zfrom) =
+  if (yfrom=yto) and not (zfrom=0) :
+    if (zfrom=1) : up_on_grid(2) else : down_on_grid(2) fi
+  elseif ypart xypoints[1] < ypart xypoints[6] :
+    up_on_grid(n)
+  else :
+    down_on_grid(n)
+  fi
+enddef ;
+
+vardef xy_on_grid (expr n, m) =
+  (xpart xypoints[n], ypart xypoints[m])
+enddef ;
+
+vardef down_to_grid (expr a,b) =
+  (xpart xypoints[a],
+   ypart xypoints[if ypart xypoints[a]<ypart xypoints[b]:a else:b fi])
+enddef ;
+
+vardef up_to_grid (expr a,b) =
+  (xpart xypoints[a],
+   ypart xypoints[if ypart xypoints[a]>ypart xypoints[b]:a else:b fi])
+enddef ;
+
+vardef left_to_grid (expr a,b) =
+  (xpart xypoints[if xpart xypoints[a]<xpart xypoints[b]:a else:b fi],
+   ypart xypoints[a])
+enddef ;
+
+vardef right_to_grid (expr a,b) =
+  (xpart xypoints[if xpart xypoints[a]>xpart xypoints[b]:a else:b fi],
+   ypart xypoints[a])
+enddef ;
+
+% vardef boundingboxfraction(expr p, f) =
+%   ((boundingbox p) enlarged (-f*bbwidth(p),-f*bbheight(p)))
+% enddef ;
+
+vardef valid_connection (expr xfrom, yfrom, xto, yto) =
+  begingroup ;
+  save ok, vc, pp ;
+  boolean ok ;
+  % check for slanted lines
+  ok := true ;
+  for i=1 upto xypoint-1 :
+   if not ((xpart xypoints[i]=xpart xypoints[i+1]) or
+           (ypart xypoints[i]=ypart xypoints[i+1])) : ok := false ;
+   fi ;
+  endfor ;
+  if not ok :
+   %message("slanted");
+    false
+  elseif forcevalid :
+   %message("force");
+    true
+  elseif (xfrom=xto) and (yfrom=yto) :
+   %message("self");
+    false
+  else :
+    % check for crossing shapes
+    pair vc ;
+    path pp ;
+
+    pair xyfirst, xylast ;
+    xyfirst := xypoints[1] ;
+    xylast := xypoints[xypoint] ;
+    trim_points ;
+    pp := for i=1 upto xypoint-1 : xypoints[i]-- endfor xypoints[xypoint] ;
+    xypoints[1] := xyfirst ;
+    xypoints[xypoint] := xylast ;
+
+    for i=1 upto max_x :
+      for j=1 upto max_y :                % was bug: xfrom,yto
+        if not ( ( (i,j)=(xfrom,yfrom) ) or ( (i,j)=(xto,yto) ) ) :
+          if not xyfree[i][j] :
+            vc := pp intersection_point xypath[i][j] ;
+            if intersection_found : ok := false fi ;
+          fi ;
+        fi ;
+      endfor ;
+    endfor ;
+   %if not ok: message("crossing") ; fi ;
+    ok
+  fi
+  endgroup
+enddef ;
+
+def connect_top_bottom (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,6) :
+    xypoints[1] := xy_top(xfrom,yfrom,zfrom,true) ;
+    xypoints[6] := xy_bottom(xto,yto,zto,true) ;
+    xypoints[2] := up_on_grid(1) ;
+    xypoints[5] := down_on_grid(6) ;
+    xypoints[3] := up_to_grid(2,5) ;
+    xypoints[4] := up_to_grid(2,5) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := x_on_grid(2,xfrom,xto,zfrom) ;
+      xypoints[4] := xy_on_grid(3,5) ;
+    fi ;
+    %%%% begin experiment
+    xypoints[3] := xypoints[3] shifted (dsp_x,0) ;
+    xypoints[4] := xypoints[4] shifted (dsp_x,0) ;
+    if dsp_y>0 :
+      xypoints[2] := xypoints[2] shifted (0,dsp_y) ;
+      xypoints[3] := xypoints[3] shifted (0,dsp_y) ;
+    elseif dsp_y<0 :
+      xypoints[4] := xypoints[4] shifted (0,dsp_y) ;
+      xypoints[5] := xypoints[5] shifted (0,dsp_y) ;
+    fi
+    %%%% end experiment
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_left_right (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,6) :
+    xypoints[1] := xy_left(xfrom,yfrom,zfrom,true) ;
+    xypoints[6] := xy_right(xto,yto,zto,true) ;
+    xypoints[2] := left_on_grid(1) ;
+    xypoints[5] := right_on_grid(6) ;
+    xypoints[3] := left_to_grid(2,5) ;
+    xypoints[4] := left_to_grid(2,5) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := y_on_grid(2,yfrom,yto,zfrom) ;
+      xypoints[4] := xy_on_grid(5,3) ;
+    fi ;
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_left_top (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,5) :
+    xypoints[1] := xy_left(xfrom,yfrom,zfrom,true) ;
+    xypoints[5] := xy_top(xto,yto,zto,true) ;
+    xypoints[2] := left_on_grid(1) ;
+    xypoints[4] := up_on_grid(5) ;
+    xypoints[3] := left_to_grid(2,5) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := xy_on_grid(2,4) ;
+    fi ;
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_left_bottom (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,5) :
+    xypoints[1] := xy_left(xfrom,yfrom,zfrom,true) ;
+    xypoints[5] := xy_bottom(xto,yto,zto,true) ;
+    xypoints[2] := left_on_grid(1) ;
+    xypoints[4] := down_on_grid(5) ;
+    xypoints[3] := left_to_grid(2,5) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := xy_on_grid(2,4) ;
+    fi ;
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_right_top (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,5) :
+    xypoints[1] := xy_right(xfrom,yfrom,zfrom,true) ;
+    xypoints[5] := xy_top(xto,yto,zto,true) ;
+    xypoints[2] := right_on_grid(1) ;
+    xypoints[4] := up_on_grid(5) ;
+    xypoints[3] := right_to_grid(2,5) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := xy_on_grid(2,4) ;
+    fi ;
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_right_bottom (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,5) :
+    xypoints[1] := xy_right(xfrom,yfrom,zfrom,true) ;
+    xypoints[5] := xy_bottom(xto,yto,zto,true) ;
+    xypoints[2] := right_on_grid(1) ;
+    xypoints[4] := down_on_grid(5) ;
+    xypoints[3] := right_to_grid(2,5) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := xy_on_grid(2,4) ;
+    fi ;
+    %%%% begin experiment
+    xypoints[2] := xypoints[2] shifted (dsp_x,0) ;
+    xypoints[3] := xypoints[3] shifted (dsp_x,0) ;
+    if dsp_y>0 :
+      xypoints[3] := xypoints[3] shifted (0,-dsp_y) ;
+      xypoints[4] := xypoints[4] shifted (0,-dsp_y) ;
+    elseif dsp_y<0 :
+      xypoints[3] := xypoints[3] shifted (0,dsp_y) ;
+      xypoints[4] := xypoints[4] shifted (0,dsp_y) ;
+    fi
+    %%%% end experiment
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_left_left (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,6) :
+    xypoints[1] := xy_left(xfrom,yfrom,zfrom,true) ;
+    xypoints[6] := xy_left(xto,yto,zto,true) ;
+    xypoints[2] := left_on_grid(1) ;
+    xypoints[5] := left_on_grid(6) ;
+    xypoints[3] := left_to_grid(2,5) ;
+    xypoints[4] := left_to_grid(5,2) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := y_on_grid(2,yfrom,yto,zfrom) ;
+      xypoints[4] := xy_on_grid(5,3) ;
+    fi ;
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_right_right (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,6) :
+    xypoints[1] := xy_right(xfrom,yfrom,zfrom,true) ;
+    xypoints[6] := xy_right(xto,yto,zto,true) ;
+    xypoints[2] := right_on_grid(1) ;
+    xypoints[5] := right_on_grid(6) ;
+    xypoints[3] := right_to_grid(2,5) ;
+    xypoints[4] := right_to_grid(5,2) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := y_on_grid(2,yfrom,yto,zfrom) ;
+      xypoints[4] := xy_on_grid(5,3) ;
+    fi ;
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_top_top (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,6) :
+    xypoints[1] := xy_top(xfrom,yfrom,zfrom,true) ;
+    xypoints[6] := xy_top(xto,yto,zto,true) ;
+    xypoints[2] := up_on_grid(1) ;
+    xypoints[5] := up_on_grid(6) ;
+    xypoints[3] := up_to_grid(2,5) ;
+    xypoints[4] := up_to_grid(5,2) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := x_on_grid(2,xfrom,xto,zfrom) ;
+      xypoints[4] := xy_on_grid(3,5) ;
+    fi ;
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_bottom_bottom (expr xfrom,yyfrom,zfrom) (expr xto,yyto,zto) =
+  yfrom := y_pos(yyfrom) ; yto := y_pos(yyto) ;
+  if points_initialized(xfrom,yfrom,xto,yto,6) :
+    xypoints[1] := xy_bottom(xfrom,yfrom,zfrom,true) ;
+    xypoints[6] := xy_bottom(xto,yto,zto,true) ;
+    xypoints[2] := down_on_grid(1) ;
+    xypoints[5] := down_on_grid(6) ;
+    xypoints[3] := down_to_grid(2,5) ;
+    xypoints[4] := down_to_grid(5,2) ;
+    if not valid_connection(xfrom,yfrom,xto,yto) :
+      xypoints[3] := x_on_grid(2,xfrom,xto,zfrom) ;
+      xypoints[4] := xy_on_grid(3,5) ;
+    fi ;
+    %%%% begin experiment
+    xypoints[3] := xypoints[3] shifted (dsp_x,0) ;
+    xypoints[4] := xypoints[4] shifted (dsp_x,0) ;
+    if dsp_y<0 :
+      xypoints[2] := xypoints[2] shifted (0,-dsp_y) ;
+      xypoints[3] := xypoints[3] shifted (0,-dsp_y) ;
+    elseif dsp_y>0 :
+      xypoints[4] := xypoints[4] shifted (0,dsp_y) ;
+      xypoints[5] := xypoints[5] shifted (0,dsp_y) ;
+    fi
+    %%%% end experiment
+    draw_connection ;
+  fi ;
+enddef ;
+
+def connect_bottom_top (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+  reverse_connection := true ;
+  connect_top_bottom (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def connect_right_left (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+  reverse_connection := true ;
+  connect_left_right (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def connect_top_left (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+  reverse_connection := true ;
+  connect_left_top (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def connect_bottom_left (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+  reverse_connection := true ;
+  connect_left_bottom (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def connect_top_right (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+  reverse_connection := true ;
+  connect_right_top (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def connect_bottom_right (expr xfrom,yfrom,zfrom) (expr xto,yto,zto) =
+  reverse_connection := true ;
+  connect_right_bottom (xto,yto,zto) (xfrom,yfrom,zfrom) ;
+enddef ;
+
+def draw_test_shape (expr x, y) =
+  draw_shape(x,y,fullcircle, .7, .7) ;
+enddef ;
+
+def draw_test_shapes =
+  for i=1 upto max_x :
+    for j=1 upto max_y :
+      draw_test_shape(i,j) ;
+    endfor ;
+  endfor ;
+enddef;
+
+def draw_test_area =
+  pickup pencircle scaled .5shape_line_width ;
+  draw (unitsquare xscaled max_x yscaled max_y shifted (1,1))
+    scaled_to_grid withcolor blue ;
+enddef ;
+
+def show_connection (expr n, m) =
+
+  begin_chart(100+n,6,6) ;
+
+    draw_test_area ;
+
+    smooth   := true ;
+    arrowtip := true ;
+    dashline := true ;
+
+    draw_test_shape(2,2) ; draw_test_shape(4,5) ;
+    draw_test_shape(3,3) ; draw_test_shape(5,1) ;
+    draw_test_shape(2,5) ; draw_test_shape(1,3) ;
+    draw_test_shape(6,2) ; draw_test_shape(4,6) ;
+
+    if     (m=1) :
+      connect_top_bottom (2,2,0) (4,5,0) ;
+      connect_top_bottom (3,3,0) (5,1,0) ;
+      connect_top_bottom (2,5,0) (1,3,0) ;
+      connect_top_bottom (6,2,0) (4,6,0) ;
+    elseif (m=2) :
+      connect_top_top (2,2,0) (4,5,0) ;
+      connect_top_top (3,3,0) (5,1,0) ;
+      connect_top_top (2,5,0) (1,3,0) ;
+      connect_top_top (6,2,0) (4,6,0) ;
+    elseif (m=3) :
+      connect_bottom_bottom (2,2,0) (4,5,0) ;
+      connect_bottom_bottom (3,3,0) (5,1,0) ;
+      connect_bottom_bottom (2,5,0) (1,3,0) ;
+      connect_bottom_bottom (6,2,0) (4,6,0) ;
+    elseif (m=4) :
+      connect_left_right (2,2,0) (4,5,0) ;
+      connect_left_right (3,3,0) (5,1,0) ;
+      connect_left_right (2,5,0) (1,3,0) ;
+      connect_left_right (6,2,0) (4,6,0) ;
+    elseif (m=5) :
+      connect_left_left (2,2,0) (4,5,0) ;
+      connect_left_left (3,3,0) (5,1,0) ;
+      connect_left_left (2,5,0) (1,3,0) ;
+      connect_left_left (6,2,0) (4,6,0) ;
+    elseif (m=6) :
+      connect_right_right (2,2,0) (4,5,0) ;
+      connect_right_right (3,3,0) (5,1,0) ;
+      connect_right_right (2,5,0) (1,3,0) ;
+      connect_right_right (6,2,0) (4,6,0) ;
+    elseif (m=7) :
+      connect_left_top (2,2,0) (4,5,0) ;
+      connect_left_top (3,3,0) (5,1,0) ;
+      connect_left_top (2,5,0) (1,3,0) ;
+      connect_left_top (6,2,0) (4,6,0) ;
+    elseif (m=8) :
+      connect_left_bottom (2,2,0) (4,5,0) ;
+      connect_left_bottom (3,3,0) (5,1,0) ;
+      connect_left_bottom (2,5,0) (1,3,0) ;
+      connect_left_bottom (6,2,0) (4,6,0) ;
+    elseif (m=9) :
+      connect_right_top (2,2,0) (4,5,0) ;
+      connect_right_top (3,3,0) (5,1,0) ;
+      connect_right_top (2,5,0) (1,3,0) ;
+      connect_right_top (6,2,0) (4,6,0) ;
+    else :
+      connect_right_bottom (2,2,0) (4,5,0) ;
+      connect_right_bottom (3,3,0) (5,1,0) ;
+      connect_right_bottom (2,5,0) (1,3,0) ;
+      connect_right_bottom (6,2,0) (4,6,0) ;
+    fi ;
+
+  end_chart ;
+
+enddef ;
+
+def show_connections =
+  for f=1 upto 10 :
+    show_connection(f,f) ;
+  endfor ;
+enddef ;
+
+%D charts
+
+def clip_chart (expr minx, miny, maxx, maxy) =
+  cmin_x := minx ;
+  cmax_x := maxx ;
+  cmin_y := miny ;
+  cmax_y := maxy ;
+enddef ;
+
+def begin_chart (expr n, maxx, maxy) =
+  new_chart ;
+  chart_figure := n ;
+  chart_scale := 1 ;
+  if chart_figure>0: beginfig(chart_figure) ; fi ;
+  initialize_grid (maxx, maxy) ;
+  bboxmargin := 0 ;
+  cmin_x := 1 ;
+  cmax_x := maxx ;
+  cmin_y := 1 ;
+  cmax_y := maxy ;
+enddef ;
+
+def end_chart =
+  flush_shapes ;
+  flush_connections ;
+  cmin_x := cmin_x ;
+  cmax_x := cmin_x+cmax_x ;
+  cmin_y := cmin_y-1 ;
+  cmax_y := cmin_y+cmax_y ;
+  if reverse_y :
+   cmin_y := y_pos(cmin_y) ;
+   cmax_y := y_pos(cmax_y) ;
+  fi ;
+  path p ;
+  p := (((cmin_x,cmin_y)--(cmax_x,cmin_y)--
+         (cmax_x,cmax_y)--(cmin_x,cmax_y)--cycle))
+       scaled_to_grid ;
+ %draw p withcolor red ;
+  p := p enlarged chart_offset ;
+  clip currentpicture to p ;
+  setbounds currentpicture to p ;
+  savedata
+    "\MPclippath{" &
+    decimal xpart llcorner p & "}{" &
+    decimal ypart llcorner p & "}{" &
+    decimal xpart urcorner p & "}{" &
+    decimal ypart urcorner p & "}" ;
+  savedata
+    "\MPareapath{" &
+    decimal (xpart llcorner p + 2chart_offset) & "}{" &
+    decimal (ypart llcorner p + 2chart_offset) & "}{" &
+    decimal (xpart urcorner p - 2chart_offset) & "}{" &
+    decimal (ypart urcorner p - 2chart_offset) & "}" ;
+  currentpicture := currentpicture scaled chart_scale ;
+  if chart_figure>0: endfig ; fi ;
+enddef ;
+
+def new_shape (expr x, y, n) =
+  if known n :
+    if (x>0) and (x<=max_x) and (y>0) and (y<=max_y) :
+      sx := shape_width/grid_width ;
+      sy := shape_height/grid_height ;
+      draw_shape(x,y,some_shape_path(n), sx, sy) ;
+    else :
+      message ("shape outside grid ignored") ;
+    fi ;
+  else
+    message ("shape not known" ) ;
+  fi ;
+enddef ;
+
+def begin_sub_chart =
+  begingroup ;
+  save    shape_line_width , connection_line_width ;
+  save    shape_line_color, shape_fill_color, connection_line_color ;
+  color   shape_line_color, shape_fill_color, connection_line_color ;
+  save    smooth, arrowtip, dashline, peepshape ;
+  boolean smooth, arrowtip, dashline, peepshape ;
+enddef ;
+
+def end_sub_chart =
+  endgroup ;
+enddef ;
+
+%D done
+
+endinput ;
+
+%D testing
+
+show_shapes(100) ;
+
+end
+
+%D more testing
+
+show_connections ;
+
+begin_chart (1,4,5) ;
+ %clip_chart(1,1,1,2) ;
+  new_shape (1,1,31) ;
+  new_shape (1,2,3) ;
+  new_shape (4,4,5) ;
+  connect_top_left   (1,1,0) (4,4,0) ;
+  connect_bottom_top (1,2,0) (4,4,0) ;
+  connect_left_right (1,2,0) (1,1,0) ;
+end_chart ;
+
+end
diff --git a/Master/texmf-dist/metapost/context/base/mp-core.mp b/Master/texmf-dist/metapost/context/base/mp-core.mp
new file mode 100644
index 00000000000..eb038163e35
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-core.mp
@@ -0,0 +1,1352 @@
+%D \module
+%D   [       file=mp-core.mp,
+%D        version=2000.something, % 1999.08.12,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=core interfacing,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_core : endinput         ; fi ;
+
+boolean context_core ; context_core := true ;
+
+pair    lxy[], rxy[], cxy[], llxy[], lrxy[], ulxy[], urxy[] ;
+path    pxy[] ;
+numeric hxy[], wxy[], dxy[], nxy[] ;
+
+def box_found (expr n,x,y,w,h,d) =
+  not ((x=0) and (y=0) and (w=0) and (h=0) and (d=0))
+enddef ;
+
+def initialize_box_pos (expr pos,n,x,y,w,h,d) =
+  pair lxy, rxy, cxy, llxy, lrxy, ulxy, urxy ;
+  path pxy ; numeric hxy, wxy, dxy, nxy;
+  lxy  := (x,y) ;
+  llxy := (x,y-d) ;
+  lrxy := (x+w,y-d) ;
+  urxy := (x+w,y+h) ;
+  ulxy := (x,y+h) ;
+  wxy  := w ;
+  hxy  := h ;
+  dxy  := d ;
+  rxy  := lxy shifted (wxy,0) ;
+  pxy  := llxy--lrxy--urxy--ulxy--cycle ;
+  cxy  := center pxy ;
+  nxy  := n ;
+  freeze_box(pos) ;
+enddef ;
+
+def freeze_box (expr pos) =
+  lxy[pos]  := lxy  ;
+  llxy[pos] := llxy ;
+  lrxy[pos] := lrxy ;
+  urxy[pos] := urxy ;
+  ulxy[pos] := ulxy ;
+  wxy[pos]  := wxy  ;
+  hxy[pos]  := hxy  ;
+  dxy[pos]  := dxy  ;
+  rxy[pos]  := rxy  ;
+  pxy[pos]  := pxy  ;
+  cxy[pos]  := cxy  ;
+  nxy[pos]  := nxy  ;
+enddef ;
+
+def initialize_box (expr n,x,y,w,h,d) =
+
+  numeric bpos ; bpos := 0 ; initialize_box_pos(bpos,n,x,y,w,h,d) ;
+
+enddef ;
+
+def initialize_area (expr fn,fx,fy,fw,fh,fd,
+                          tn,tx,ty,tw,th,td) =
+
+  numeric fpos ; fpos := 1 ; initialize_box_pos(fpos,fn,fx,fy,fw,fh,fd) ;
+  numeric tpos ; tpos := 2 ; initialize_box_pos(tpos,tn,tx,ty,tw,th,td) ;
+
+  do_initialize_area (fpos, tpos) ;
+
+enddef ;
+
+def do_initialize_area (expr fpos, tpos) =
+  lxy  := lxy[fpos] ;
+  llxy := (xpart llxy[fpos], ypart llxy[tpos]) ;
+  lrxy := lrxy[tpos] ;
+  urxy := (xpart urxy[tpos], ypart urxy[fpos]) ;
+  ulxy := ulxy[fpos] ;
+  wxy  := xpart lrxy - xpart llxy ;
+  hxy  := hxy[fpos] ;
+  dxy  := dxy[tpos] ;
+  rxy  := lxy shifted (wxy,0) ;
+  pxy  := llxy--lrxy--urxy--ulxy--cycle ;
+  cxy  := center pxy ;
+enddef ;
+
+def set_par_line_height (expr ph, pd) =
+  par_strut_height :=
+    if ph>0 : ph elseif StrutHeight>0 : StrutHeight else : 8pt fi ;
+  par_strut_depth  :=
+    if pd>0 : pd elseif StrutDepth >0 : StrutDepth  else : 3pt fi ;
+  par_line_height  :=
+    par_strut_height + par_strut_depth ;
+enddef ;
+
+def initialize_par (expr fn,fx,fy,fw,fh,fd,
+                         tn,tx,ty,tw,th,td,
+                         mn,mx,my,mw,mh,md,
+                         pn,px,py,pw,ph,pd,
+                         rw,rl,rr,rh,ra,ri) =
+
+  numeric fpos ; fpos := 1 ; initialize_box_pos(fpos,fn,fx,fy,fw,fh,fd) ;
+  numeric tpos ; tpos := 2 ; initialize_box_pos(tpos,tn,tx,ty,tw,th,td) ;
+  numeric mpos ; mpos := 3 ; initialize_box_pos(mpos,mn,mx,my,mw,mh,md) ;
+  numeric ppos ; ppos := 4 ; initialize_box_pos(ppos,pn,px,py,pw,ph,pd) ;
+
+  numeric par_strut_height, par_strut_depth, par_line_height ;
+
+  set_par_line_height (ph, pd) ;
+
+  do_initialize_area (fpos, tpos) ;
+  do_initialize_par  (fpos, tpos, mpos, ppos, rw,rl,rr,rh,ra,ri) ;
+
+enddef ;
+
+def initialize_area_par (expr fn,fx,fy,fw,fh,fd,
+                              tn,tx,ty,tw,th,td,
+                              wn,wx,wy,ww,wh,wd) =
+
+  numeric fpos ; fpos := 1 ; initialize_box_pos(fpos,fn,fx,fy,fw,fh,fd) ;
+  numeric tpos ; tpos := 2 ; initialize_box_pos(tpos,tn,tx,ty,tw,th,td) ;
+  numeric wpos ; wpos := 3 ; initialize_box_pos(wpos,wn,wx,wy,ww,wh,wd) ;
+
+  numeric par_strut_height, par_strut_depth, par_line_height ;
+
+  set_par_line_height (wh, wd) ;
+
+  numeric ffpos ; ffpos := 4 ; initialize_box_pos(ffpos,wn,wx,fy,0,wh,wd) ;
+  numeric ttpos ; ttpos := 5 ; initialize_box_pos(ttpos,wn,wx+ww,ty,0,wh,wd) ;
+
+  do_initialize_area (ffpos, ttpos) ;
+
+  numeric mpos ; mpos := 6 ; freeze_box(mpos) ;
+
+% do_initialize_area (fpos, tpos) ;
+  do_initialize_par  (fpos, tpos, mpos, ffpos, 0,0,0,0,0,0) ;
+
+enddef ;
+
+def do_initialize_par (expr fpos, tpos, mpos, ppos, rw,rl,rr,rh,ra,ri) =
+
+  pair lref, rref, pref, lhref, rhref ;
+
+  % clip the page area to the left and right skips
+
+  llxy[mpos] := llxy[mpos] shifted (+rl,0) ;
+  lrxy[mpos] := lrxy[mpos] shifted (-rr,0) ;
+  urxy[mpos] := urxy[mpos] shifted (-rr,0) ;
+  ulxy[mpos] := ulxy[mpos] shifted (+rl,0) ;
+
+  % fixate the leftskip, rightskip and hanging indentation
+
+  lref := (xpart llxy[mpos],ypart ulxy[ppos]) ; lhref := lref shifted (rh,0) ;
+  rref := (xpart lrxy[mpos],ypart urxy[ppos]) ; rhref := rref shifted (rh,0) ;
+
+  pref := lxy[ppos] ;
+
+  if nxy[tpos] > nxy[fpos] :
+    if nxy[fpos] = nxy[mpos] :
+      % first of multiple pages
+      llxy[tpos] := llxy[mpos] ;
+      lrxy[tpos] := lrxy[mpos] ;
+      urxy[tpos] := lrxy[mpos] shifted (0,par_line_height) ;
+      ulxy[tpos] := llxy[mpos] shifted (0,par_line_height) ;
+      boxgriddirection := down ;
+    elseif nxy[tpos] = nxy[mpos] :
+      % last of multiple pages
+      llxy[fpos] := ulxy[mpos] shifted (0,-par_line_height) ;
+      lrxy[fpos] := urxy[mpos] shifted (0,-par_line_height) ;
+      urxy[fpos] := urxy[mpos] ;
+      ulxy[fpos] := ulxy[mpos] ;
+      boxgriddirection := up ;
+    else :
+      % middle of multiple pages
+      llxy[fpos] := ulxy[mpos] shifted (0,-par_line_height) ;
+      lrxy[fpos] := urxy[mpos] shifted (0,-par_line_height) ;
+      urxy[fpos] := urxy[mpos] ;
+      ulxy[fpos] := ulxy[mpos] ;
+      llxy[tpos] := llxy[mpos] ;
+      lrxy[tpos] := lrxy[mpos] ;
+      urxy[tpos] := lrxy[mpos] shifted (0,par_line_height) ;
+      ulxy[tpos] := llxy[mpos] shifted (0,par_line_height) ;
+      boxgriddirection := up ;
+    fi ;
+  else :
+    % just one page
+    boxgriddirection := up ;
+  fi ;
+
+  path txy, bxy, pxy, mxy ;
+
+  txy := originpath ; % top
+  bxy := originpath ; % bottom
+  pxy := originpath ; % composed
+
+  boolean lefthang, righthang, somehang ;
+
+  % we only hang on the first of a multiple page background
+
+  if nxy[mpos] > nxy[fpos] :
+    lefthang := righthang := somehang := false ;
+  else :
+    lefthang := (rh>0) ; righthang := (rh<0) ; somehang := false ;
+  fi ;
+
+  if lefthang :
+    mxy  := boundingbox (lref -- lref shifted (rh,ra*par_line_height)) ;
+  elseif righthang :
+    mxy  := boundingbox (rref -- rref shifted (rh,ra*par_line_height)) ;
+  else :
+    mxy  := originpath ;
+  fi ;
+
+  if round(ypart llxy[fpos]) = round(ypart llxy[tpos]) :
+
+    % We have a one-liner. Watch how er use the bottom pos for
+    % determining the height.
+
+    llxy[fpos] := (xpart llxy[fpos], ypart llxy[tpos]) ;
+    ulxy[fpos] := (xpart ulxy[fpos], ypart ulxy[tpos]) ;
+
+  else :
+
+    % We have a multi-liner. For convenience we now correct the
+    % begin and end points for indentation.
+
+    if lefthang and (round(ypart llxy[tpos]) >= round(ypart lrcorner mxy)) :
+      llxy[tpos] := (xpart lhref, ypart llxy[tpos]) ;
+      ulxy[tpos] := (xpart lhref, ypart ulxy[tpos]) ;
+    else :
+      llxy[tpos] := (xpart  lref, ypart llxy[tpos]) ;
+      ulxy[tpos] := (xpart  lref, ypart ulxy[tpos]) ;
+    fi ;
+
+    if righthang and (round(ypart lrxy[fpos]) >= round(ypart llcorner mxy)) :
+      lrxy[fpos] := (xpart rhref, ypart lrxy[fpos]) ;
+      urxy[fpos] := (xpart rhref, ypart urxy[fpos]) ;
+    else :
+      lrxy[fpos] := (xpart  rref, ypart lrxy[fpos]) ;
+      urxy[fpos] := (xpart  rref, ypart urxy[fpos]) ;
+    fi ;
+
+  fi ;
+
+  somehang := (ypart ulxy[fpos]>ypart llcorner mxy) and
+              (ypart llxy[tpos]<ypart llcorner mxy) ;
+
+  if round(ypart llxy[fpos]) = round(ypart llxy[tpos]) :
+
+    % A (short) one-liner goes into the top box.
+
+    txy := llxy[fpos] -- lrxy[tpos] -- urxy[tpos] -- ulxy[fpos] -- cycle ;
+
+  elseif (round(ypart llxy[fpos]) = round(ypart ulxy[tpos])) and
+         (round(xpart lrxy[tpos]) < round(xpart llxy[fpos])) :
+
+    % We have a sentence that spans two lines but with only end
+    % of line and begin of line segments. We need to take care of
+    % indentation.
+
+    txy := llxy[fpos] -- lrxy[fpos] -- urxy[fpos] -- ulxy[fpos] -- cycle ;
+    bxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] -- ulxy[tpos] -- cycle ;
+
+  elseif (round(ypart llxy[fpos]) = round(ypart ulxy[tpos])) :
+
+    % We have a sentence that spans two lines but with overlap.
+
+    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] -- lrxy[fpos] --
+           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] -- ulxy[tpos] -- cycle ;
+
+  elseif lefthang and somehang :
+
+    % We have a sentence that spans more than two lines with
+    % left hanging indentation.
+
+    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] --
+           (xpart urxy[fpos],ypart urxy[tpos]) --
+           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] --
+           if round(ypart urxy[tpos]) < round(ypart llcorner mxy) :
+             (xpart lrcorner mxy,ypart llxy[fpos]) --
+             lrcorner mxy --
+             (xpart llxy[tpos],ypart llcorner mxy) --
+           else :
+             (xpart llxy[tpos],ypart llxy[fpos]) --
+           fi
+           cycle ;
+
+  elseif righthang and somehang :
+
+    % We have a sentence that spans more than two lines with
+    % right hanging indentation.
+
+    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] --
+           if round(ypart urxy[tpos]) < round(ypart llcorner mxy) :
+             (xpart lrcorner mxy,ypart urxy[tpos]) --
+             lrcorner mxy -- llcorner mxy --
+           else :
+             (xpart urxy[fpos],ypart urxy[tpos]) --
+           fi
+           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] --
+           (xpart llxy[tpos],ypart llxy[fpos]) --
+           cycle ;
+
+  else :
+
+    % We have a sentence that spans more than two lines with
+    % no hanging indentation.
+
+    pxy := llxy[tpos] -- lrxy[tpos] -- urxy[tpos] --
+           (xpart urxy[fpos],ypart urxy[tpos]) --
+           urxy[fpos] -- ulxy[fpos] -- llxy[fpos] --
+           (xpart llxy[tpos],ypart llxy[fpos]) -- cycle ;
+
+  fi ;
+
+  pxy := simplified pxy ;
+  pxy := unspiked   pxy ;
+
+enddef ;
+
+TopSkip     := 0 ; % will move
+StrutHeight := 0 ; % will move
+
+pair last_multi_par_shift ; last_multi_par_shift := origin ;
+
+def relocate_multipars (expr xy) =
+  last_multi_par_shift := xy ;
+  for i=1 upto nofmultipars :
+    multipars[i] := multipars[i] shifted last_multi_par_shift ;
+  endfor ;
+enddef ;
+
+boolean compensate_multi_par_topskip ;
+boolean span_multi_column_pars ;
+boolean auto_multi_par_hsize ;
+boolean enable_multi_par_fallback ;
+
+compensate_multi_par_topskip := true ;
+span_multi_column_pars       := false ;
+auto_multi_par_hsize         := false ; % true ;
+enable_multi_par_fallback    := true ;
+
+vardef multi_par_at_top (expr i) =
+  (round (ypart ulcorner multipars[i]) = round (ypart ulcorner
+     (TextAreas[multirefs[i]] shifted last_multi_par_shift)))
+enddef ;
+
+numeric nofmultipars ; nofmultipars := 0 ;
+
+boolean obey_multi_par_hang   ; obey_multi_par_hang   := true ;
+boolean obey_multi_par_more   ; obey_multi_par_more   := true ;
+boolean snap_multi_par_tops   ; snap_multi_par_tops   := true ;
+boolean local_multi_par_area  ; local_multi_par_area  := false ;
+boolean ignore_multi_par_page ; ignore_multi_par_page := false ;
+
+boolean one_piece_multi_par   ; one_piece_multi_par   := false ;
+
+def simplify_multi_pars = % boundingbox ipv shape als optie
+  for i := 1 upto nofmultipars :
+    multipars[i] := boundingbox multipars[i] ;
+  endfor ;
+enddef ;
+
+def save_multipar (expr i, l, p) =
+  nofmultipars := nofmultipars + 1 ;
+  multirefs[nofmultipars] := i ;
+  multilocs[nofmultipars] := l ;
+  multipars[nofmultipars] := unspiked (simplified p) ;
+enddef ;
+
+def prepare_multi_pars (expr fn,fx,fy,fw,fh,fd,
+                             tn,tx,ty,tw,th,td,
+                             wn,wx,wy,ww,wh,wd,
+                             pn,px,py,pw,ph,pd,
+                             rw,rl,rr,rh,ra,ri) =
+
+  if span_multi_column_pars :
+    begingroup ;
+    save TextAreas ; path TextAreas[] ;
+    save NOfTextAreas ; numeric NOfTextAreas ;
+    for i=1 upto NOfTextColumns :
+      TextAreas[i] := TextColumns[i] ;
+    endfor ;
+    NOfTextAreas := NOfTextColumns ;
+  fi ;
+
+  last_multi_par_shift := origin ;
+
+  numeric fpos ; fpos := 1 ; initialize_box_pos(fpos,fn,fx,fy,fw,fh,fd) ;
+  numeric tpos ; tpos := 2 ; initialize_box_pos(tpos,tn,tx,ty,tw,th,td) ;
+  numeric wpos ; wpos := 3 ; initialize_box_pos(wpos,wn,wx,wy,ww,wh,wd) ;
+  numeric ppos ; ppos := 4 ; initialize_box_pos(ppos,pn,px,py,pw,ph,pd) ;
+
+  if local_multi_par_area :
+    RealPageNumber := fn ;
+    NOfTextAreas := 1 ;
+    NOfSavedTextAreas := 0 ;
+    TextAreas[1] := TextAreas[0] ;
+    TextColumns[1] := TextColumns[0] ;
+    nxy[fpos] := nxy[tpos] := nxy[wpos] := nxy[ppos] := RealPageNumber ;
+   % draw TextColumns[1] withcolor green ;
+   % draw TextAreas[1] withcolor green ;
+  elseif ignore_multi_par_page :
+    RealPageNumber := fn ;
+    nxy[fpos] := nxy[tpos] := nxy[wpos] := nxy[ppos] := RealPageNumber ;
+  fi ;
+
+  numeric par_strut_height, par_strut_depth, par_line_height ;
+
+  set_par_line_height (ph, pd) ;
+
+  numeric par_hang_indent, par_hang_after, par_indent, par_left_skip ;
+
+  par_hang_indent  := rh ;
+  par_hang_after   := ra ;
+  par_indent       := ri ;
+  par_left_skip    := rl ;
+
+  pair par_start_pos ;
+
+% par_start_pos := llxy[fpos] if par_indent<0: shifted (-par_indent,0) fi ;
+
+  par_start_pos := llxy[fpos]
+    if par_indent   <0: shifted (-par_indent,   0) fi
+    if par_left_skip<0: shifted (-par_left_skip,0) fi ;
+
+  if wxy[wpos]>0 :
+    left_skip  := rl + xpart llxy[wpos] - xpart llxy[ppos] ;
+    right_skip := rw - left_skip - ww ;
+  else :
+    left_skip  := rl ;
+    right_skip := rr ;
+  fi ;
+
+  path    multipar, multipars[] ;
+  numeric multiref, multirefs[] ;
+  numeric multiloc, multilocs[] ; % 1=begin 2=between 3=end
+
+  numeric multi_par_pages ; multi_par_pages := nxy[tpos]-nxy[fpos]+1 ;
+
+  ii := 0 ; nn := NOfTextAreas+1 ; nofmultipars := 0 ;
+
+  vardef snapped_multi_pos (expr p) =
+    if snap_multi_par_tops :
+      if abs(ypart p - ypart ulcorner multipar) < par_line_height :
+        (xpart p,ypart ulcorner multipar)
+      else :
+        p
+      fi
+    else :
+      p
+    fi
+  enddef ;
+
+  % def set_multipar (expr i) =
+  %   ((TextAreas[i] leftenlarged -left_skip) rightenlarged -right_skip)
+  % enddef ;
+
+  vardef set_multipar (expr i) =
+    ( (TextAreas[i] leftenlarged -left_skip) rightenlarged (-right_skip
+      if auto_multi_par_hsize : + rw - bbwidth(TextAreas[i]) fi) )
+  enddef ;
+
+  vardef top_multi_par(expr p) =
+    (round(estimated_par_lines(bbheight(p)*par_line_height))=round(bbheight(p)))
+  enddef ;
+
+  vardef multi_par_tsc(expr p) =
+    if top_multi_par(p) : TopSkipCorrection else : 0 fi
+  enddef ;
+
+  vardef estimated_par_lines (expr h) =
+    round(h/par_line_height)
+  enddef ;
+
+  vardef estimated_multi_par_height (expr n, t) =
+    if round(par_line_height)=0 :
+      0
+    else :
+      save ok, h ; boolean ok ;
+      numeric h ; h := 0 ;
+      ok := false ;
+      if (nxy[fpos]=RealPageNumber-1) :
+        for i := 1 upto NOfSavedTextAreas :
+          if (InsideSavedTextArea(i,par_start_pos)) :
+            ok := true ;
+            h := h + estimated_par_lines(ypart ulxy[fpos] -
+                   ypart llcorner SavedTextAreas[i]) ;
+          elseif ok :
+            h := h + estimated_par_lines(bbheight(SavedTextAreas[i])) ;
+          fi ;
+        endfor ;
+      fi ;
+      if ok :
+        for i := 1 upto n-1 :
+          h := h + estimated_par_lines(bbheight(TextAreas[i])) ;
+        endfor ;
+      else :
+        % already: ok := false ;
+        for i := 1 upto n-1 :
+          if (InsideTextArea(i,par_start_pos)) :
+            ok := true ;
+            h := h + estimated_par_lines(ypart ulxy[fpos] - ypart llcorner TextAreas[i]) ;
+          elseif ok :
+            h := h + estimated_par_lines(bbheight(TextAreas[i])) ;
+          fi ;
+        endfor ;
+      fi ;
+      h
+    fi
+  enddef ;
+
+  vardef left_top_hang (expr same_area) =
+
+par_hang_after := ra + estimated_par_lines(py-fy) ;
+
+    if (par_hang_indent>0) and (par_hang_after<0) and obey_multi_par_hang :
+      pair _ul_ ; _ul_ := (xpart ulcorner multipar, ypart snapped_multi_pos(ulxy[fpos]));
+      pair _pa_ ; _pa_ := _ul_ shifted (0,par_hang_after*par_line_height) ;
+%       _pa_ := (xpart _pa_,max(ypart _pa_,ypart llcorner multipar)) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_ -TopSkipCorrection,ypart llcorner multipar)) ;
+      if same_area :
+%         _pa_ := (xpart _pa_,max(ypart _pa_,ypart llxy[tpos])) ;
+        _pa_ := (xpart _pa_,max(ypart _pa_ -TopSkipCorrection,ypart llxy[tpos])) ;
+      fi ;
+      if obey_multi_par_more and (round(par_line_height)>0) :
+        par_hang_after := min(0,round(par_hang_after +
+          (ypart urxy[fpos]-ypart _pa_)/par_line_height)) ;
+      fi ;
+      (xpart _ul_ + par_hang_indent, ypart lrxy[fpos]) --
+      (xpart _ul_ + par_hang_indent, ypart _pa_) --
+      (xpart ulcorner multipar, ypart _pa_)
+    else :
+      (xpart ulcorner multipar, ypart lrxy[fpos])
+    fi
+  enddef ;
+
+  vardef right_top_hang (expr same_area) =
+
+% par_hang_after := ra - estimated_par_lines(py-fy) ;
+par_hang_after := ra + estimated_par_lines(py-fy) ;
+
+    if (par_hang_indent<0) and (par_hang_after<0) and obey_multi_par_hang :
+      pair _ur_ ; _ur_ := (xpart urcorner multipar, ypart snapped_multi_pos(urxy[fpos])) ;
+      pair _pa_ ; _pa_ := _ur_ shifted (0,par_hang_after*par_line_height) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_ -TopSkipCorrection,ypart llcorner multipar)) ;
+      if same_area :
+        _pa_ := (xpart _pa_,max(ypart _pa_ -TopSkipCorrection,ypart snapped_multi_pos(ulxy[tpos]))) ;
+      fi ;
+      if obey_multi_par_more and (round(par_line_height)>0) :
+        par_hang_after := min(0,round(par_hang_after +
+          (ypart urxy[fpos]-ypart _pa_)/par_line_height)) ;
+      fi ;
+      (xpart urcorner multipar, ypart _pa_) --
+      (xpart _ur_ + par_hang_indent, ypart _pa_) --
+      (xpart _ur_ + par_hang_indent, ypart snapped_multi_pos(urxy[fpos]))
+    else :
+      (xpart urcorner multipar, ypart snapped_multi_pos(urxy[fpos]))
+    fi
+  enddef ;
+
+  vardef x_left_top_hang (expr i, t) =
+    par_hang_after := min(0,ra + estimated_multi_par_height(i,t)) ;
+    if (par_hang_indent>0) and (par_hang_after<0) :
+      pair _ul_ ; _ul_ := ulcorner multipar ;
+      pair _pa_ ; _pa_ := _ul_ shifted (0,par_hang_after*par_line_height) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart llcorner multipar)) ;
+
+if t :
+  _pa_ := (xpart _pa_,max(ypart _pa_,ypart llxy[tpos]));
+fi ;
+if abs(ypart _pa_-ypart llxy[tpos])<par_line_height :
+  _pa_ := (xpart _pa_,ypart llxy[tpos]);
+fi ;
+if abs(ypart _pa_-ypart llcorner multipar)<par_line_height :
+  _pa_ := (xpart _pa_,ypart llcorner multipar);
+fi ;
+
+      (xpart _ul_, ypart _pa_) --
+      (xpart _ul_ + par_hang_indent, ypart _pa_) --
+      (xpart _ul_ + par_hang_indent, ypart _ul_)
+    else :
+      ulcorner multipar
+    fi
+  enddef ;
+
+% here
+
+  vardef x_right_top_hang (expr i, t) =
+    par_hang_after := min(0,ra + estimated_multi_par_height(i,t)) ;
+    if (par_hang_indent<0) and (par_hang_after<0) :
+      pair _ur_ ; _ur_ := urcorner multipar ;
+      pair _pa_ ; _pa_ := _ur_ shifted (0,par_hang_after*par_line_height) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart lrcorner multipar)) ;
+if t :
+  _pa_ := (xpart _pa_,max(ypart _pa_,ypart snapped_multi_pos(urxy[tpos]))) ;
+fi ;
+
+%todo
+%
+%if abs(ypart _pa_-ypart llxy[tpos])<par_line_height :
+%  _pa_ := (xpart _pa_,ypart llxy[tpos]);
+%fi ;
+%if abs(ypart _pa_-ypart llcorner multipar)<par_line_height :
+%  _pa_ := (xpart _pa_,ypart llcorner multipar);
+%fi ;
+
+      (xpart _ur_ + par_hang_indent, ypart _ur_) --
+      (xpart _ur_ + par_hang_indent, ypart _pa_) --
+      (xpart _ur_, ypart _pa_)
+    else :
+      urcorner multipar
+    fi
+  enddef ;
+
+  vardef left_bottom_hang (expr same_area) =
+    pair _ll_, _sa_, _pa_ ;
+    _sa_ := if same_area : llxy[tpos] else : lrcorner multipar fi ;
+    if (par_hang_indent>0) and (par_hang_after>0) and obey_multi_par_hang :
+      _ll_ := (xpart ulcorner multipar, ypart snapped_multi_pos(ulxy[fpos])) ;
+      _pa_ := _ll_ shifted (0,-par_hang_after*par_line_height) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart llcorner multipar)) ;
+      if same_area :
+        _pa_ := (xpart _pa_,max(ypart _pa_,ypart _sa_)) ;
+      fi ;
+      if obey_multi_par_more and (round(par_line_height)>0) :
+        par_hang_after := max(0,round(par_hang_after -
+          (ypart urxy[fpos]-ypart _pa_)/par_line_height)) ;
+      fi ;
+      _pa_ --
+      (xpart _pa_ + par_hang_indent,ypart _pa_) --
+      (xpart _pa_ + par_hang_indent,ypart _sa_)
+    else :
+      (xpart llcorner multipar, ypart _sa_)
+    fi
+  enddef ;
+
+  vardef right_bottom_hang (expr same_area) =
+    pair _lr_, _sa_, _pa_ ;
+    _sa_ := if same_area : snapped_multi_pos(ulxy[tpos]) else : lrcorner multipar fi ;
+    if (par_hang_indent<0) and (par_hang_after>0) and obey_multi_par_hang :
+      _lr_ := (xpart urcorner multipar, ypart snapped_multi_pos(urxy[fpos])) ;
+      _pa_ := _lr_ shifted (0,-par_hang_after*par_line_height) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart lrcorner multipar)) ;
+      if same_area :
+        _pa_ := (xpart _pa_,max(ypart _pa_,ypart snapped_multi_pos(ulxy[tpos]))) ;
+      fi ;
+      if obey_multi_par_more and (round(par_line_height)>0) :
+        par_hang_after := max(0,round(par_hang_after -
+          (ypart urxy[fpos]-ypart _pa_)/par_line_height)) ;
+      fi ;
+      (xpart _pa_ + par_hang_indent,ypart _sa_) --
+      (xpart _pa_ + par_hang_indent,ypart _pa_) --
+      _pa_
+    else :
+     (xpart lrcorner multipar, ypart _sa_)
+    fi
+  enddef ;
+
+  vardef x_left_bottom_hang (expr i, t) =
+    pair _ll_, _sa_, _pa_ ;
+    _sa_ := if t : llxy[tpos] else : llcorner multipar fi ;
+    if (par_hang_indent>0) and (ra>0) :
+      par_hang_after := max(0,ra - estimated_multi_par_height(i,t)) ;
+      _ll_ := ulcorner multipar ;
+      _pa_ := _ll_ shifted (0,-par_hang_after*par_line_height) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart llcorner multipar)) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart _sa_)) ;
+      % we need to compensate for topskip enlarged areas
+      if abs(ypart _pa_ - ypart _sa_) > par_line_height :
+        (xpart _pa_ + par_hang_indent,ypart _sa_) --
+        (xpart _pa_ + par_hang_indent,ypart _pa_) --
+      fi
+      _pa_
+    else :
+      (xpart llcorner multipar, ypart _sa_)
+    fi
+  enddef ;
+
+  vardef x_right_bottom_hang (expr i, t) =
+    pair _lr_, _sa_, _pa_ ;
+    _sa_ := if t : snapped_multi_pos(ulxy[tpos]) else : llcorner multipar fi ;
+    if (par_hang_indent<0) and (ra>0) :
+      par_hang_after := max(0,ra - estimated_multi_par_height(i, t)) ;
+      _lr_ := urcorner multipar ;
+      _pa_ := _lr_ shifted (0,-par_hang_after*par_line_height) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart lrcorner multipar)) ;
+      _pa_ := (xpart _pa_,max(ypart _pa_,ypart _sa_)) ;
+      % we need to compensate for topskip enlarged areas
+      _pa_
+      if abs(ypart _pa_ - ypart _sa_) > par_line_height :
+        -- (xpart _pa_ + par_hang_indent,ypart _pa_)
+        -- (xpart _pa_ + par_hang_indent,ypart _sa_)
+      fi
+    else :
+     (xpart lrcorner multipar, ypart _sa_)
+    fi
+  enddef ;
+
+  def test_multipar =
+%     multipar :=
+%       llcorner multipar --
+%       urcorner multipar --
+%       lrcorner multipar --
+%       ulcorner multipar --
+%       cycle ;
+    multipar := boundingbox multipar ;
+  enddef ;
+
+  % first loop
+
+  if enable_multi_par_fallback  and
+     (nxy[fpos]=RealPageNumber) and
+     (nxy[tpos]=RealPageNumber) and not
+     (InsideSomeTextArea(lxy[fpos]) and
+      InsideSomeTextArea(rxy[tpos])) :
+
+  % fallback
+
+     multipar :=
+
+      llxy[fpos] --
+      lrxy[tpos] --
+      urxy[tpos] --
+      ulxy[fpos] -- cycle ;
+
+      save_multipar (1,1,multipar) ;
+
+  else :
+
+  % normal
+
+  for i=1 upto NOfTextAreas :
+
+    TopSkipCorrection := 0 ;
+
+    multipar := set_multipar(i) ;
+
+    % watch how we compensate for negative indentation
+
+    if (nxy[fpos]=RealPageNumber) and (InsideTextArea(i,par_start_pos)) :
+
+
+      % first one in chain
+
+      ii := i ;
+
+      if (nxy[tpos]=RealPageNumber) and (InsideTextArea(i,llxy[tpos])) :
+
+        % in same area
+
+        nn := i ;
+
+        if compensate_multi_par_topskip and (round(LineHeight-ph-pd)=0) :
+
+          TopSkipCorrection := TopSkip - StrutHeight ;
+
+          if round(ypart ulxy[fpos] + TopSkipCorrection) =
+             round(ypart ulcorner TextAreas[i]) :
+            ulxy[fpos] := ulxy[fpos] shifted (0,TopSkipCorrection) ;
+            urxy[fpos] := urxy[fpos] shifted (0,TopSkipCorrection) ;
+          else :
+            TopSkipCorrection := 0 ;
+          fi ;
+
+        fi ;
+
+        if ypart llxy[fpos] = ypart llxy[tpos] :
+
+          multipar :=
+            llxy[fpos] --
+            lrxy[tpos] --
+           %urxy[tpos] --
+            snapped_multi_pos(urxy[tpos]) --
+           %ulxy[fpos] --
+            snapped_multi_pos(ulxy[fpos]) --
+            cycle ;
+
+          save_multipar (i,1,multipar) ;
+
+        elseif (ypart llxy[fpos] = ypart ulxy[tpos]) and
+               (xpart llxy[tpos] < xpart llxy[fpos]) :
+
+          % two loners
+
+          multipar := if obey_multi_par_hang :
+
+            right_bottom_hang(true) --
+            right_top_hang(true) --
+            snapped_multi_pos(urxy[fpos]) --
+            lrxy[fpos] --
+
+          else :
+
+            llxy[fpos] --
+            (xpart urcorner multipar, ypart llxy[fpos]) --
+            (xpart urcorner multipar, ypart ulxy[fpos]) --
+            snapped_multi_pos(ulxy[fpos]) --
+
+          fi cycle ;
+
+          save_multipar (i,1,multipar) ;
+
+          multipar := set_multipar(i) ;
+
+          multipar := if obey_multi_par_hang :
+
+            left_bottom_hang(true) --
+            llxy[tpos] --
+            snapped_multi_pos(ulxy[tpos]) --
+            left_top_hang(true) --
+
+          else :
+
+            (xpart llcorner multipar, ypart llxy[tpos]) --
+            llxy[tpos] --
+            snapped_multi_pos(ulxy[tpos]) --
+            (xpart llcorner multipar, ypart ulxy[tpos]) --
+
+          fi cycle ;
+
+          save_multipar (i,1,multipar) ;
+
+        else :
+
+          multipar := if obey_multi_par_hang :
+
+            left_bottom_hang(true) --
+            llxy[tpos] --
+           %ulxy[tpos] --
+            snapped_multi_pos(ulxy[tpos]) --
+            right_bottom_hang(true) --
+            right_top_hang(true) --
+           %urxy[fpos] --
+            snapped_multi_pos(urxy[fpos]) --
+            lrxy[fpos] --
+            left_top_hang(true) --
+
+          else :
+
+            (xpart llcorner multipar, ypart llxy[tpos]) --
+            llxy[tpos] --
+           %ulxy[tpos] --
+            snapped_multi_pos(ulxy[tpos]) --
+            (xpart lrcorner multipar, ypart ulxy[tpos]) --
+            (xpart urcorner multipar, ypart urxy[fpos]) --
+           %urxy[fpos] --
+            snapped_multi_pos(urxy[fpos]) --
+            lrxy[fpos] --
+            (xpart ulcorner multipar, ypart lrxy[fpos]) --
+
+          fi cycle ;
+
+          save_multipar (i,1,multipar) ;
+
+        fi ;
+
+      else :
+
+        multipar := if obey_multi_par_hang :
+
+          left_bottom_hang(false) --
+          right_bottom_hang(false) --
+          right_top_hang(false) --
+         %urxy[fpos] --
+          snapped_multi_pos(urxy[fpos]) --
+          lrxy[fpos] --
+          left_top_hang(false) --
+
+        else :
+
+          llcorner multipar --
+          lrcorner multipar --
+          (xpart urcorner multipar, ypart urxy[fpos]) --
+         %urxy[fpos] --
+          snapped_multi_pos(urxy[fpos]) --
+          lrxy[fpos] --
+          (xpart ulcorner multipar, ypart lrxy[fpos]) --
+
+        fi cycle ;
+
+        save_multipar (i,1,multipar) ;
+
+      fi ;
+
+    elseif (nxy[tpos]=RealPageNumber) and (InsideTextArea(i,llxy[tpos])) :
+
+      % last one in chain
+
+      nn := i ;
+
+      if obey_multi_par_hang and obey_multi_par_more :
+
+        multipar :=
+          x_left_top_hang(i,true) --
+          x_right_top_hang(i,true) --
+          x_right_bottom_hang(i,true) --
+%          ulxy[tpos] --
+snapped_multi_pos(ulxy[tpos]) --
+          llxy[tpos] --
+          x_left_bottom_hang(i,true) --
+          cycle ;
+
+      else :
+
+        multipar :=
+          ulcorner multipar --
+          urcorner multipar --
+          (xpart lrcorner multipar, ypart urxy[tpos]) --
+%          ulxy[tpos] --
+snapped_multi_pos(ulxy[tpos]) --
+          llxy[tpos] --
+          (xpart llcorner multipar, ypart llxy[tpos]) --
+          cycle ;
+
+      fi ;
+
+      save_multipar (i,3,multipar) ;
+
+    else :
+
+      % handled later
+
+    fi ;
+
+  endfor ;
+
+  % second loop
+
+  for i=ii+1 upto nn-1 :
+
+    % rest of chain / todo : hang
+
+%if (nxy[fpos]<=RealPageNumber) and (nxy[tpos]>=RealPageNumber) :
+
+    multipar := set_multipar(i) ;
+
+    if obey_multi_par_hang and obey_multi_par_more :
+
+      multipar :=
+        x_left_top_hang(i,false) --
+        x_right_top_hang(i,false) --
+        x_right_bottom_hang(i,false) --
+        x_left_bottom_hang(i,false) --
+        cycle ;
+
+    fi ;
+
+    save_multipar(i,2,multipar) ;
+
+%fi ;
+
+  endfor ;
+
+  % end of normal/fallback
+
+fi ;
+
+  if span_multi_column_pars :
+    endgroup ;
+  fi ;
+
+  % quick hack for gb:
+
+  one_piece_multi_par := (nofmultipars=1) and (pn=tn) ;
+
+enddef ;
+
+color   boxgridcolor     ; boxgridcolor     := .8red ;
+color   boxlinecolor     ; boxlinecolor     := .8blue ;
+color   boxfillcolor     ; boxfillcolor     := .8white ;
+numeric boxgridtype      ; boxgridtype      := 0 ;
+numeric boxlinetype      ; boxlinetype      := 1 ;
+numeric boxfilltype      ; boxfilltype      := 1 ;
+pair    boxgriddirection ; boxgriddirection := up ;
+numeric boxgridwidth     ; boxgridwidth     := 1pt ;
+numeric boxlinewidth     ; boxlinewidth     := 1pt ;
+numeric boxlineradius    ; boxlineradius    := 0pt ;
+numeric boxfilloffset    ; boxfilloffset    := 0pt ;
+numeric boxgriddistance  ; boxgriddistance  := .5cm ;
+
+def draw_box =
+  draw pxy withcolor boxlinecolor withpen pencircle scaled boxlinewidth ;
+  draw lxy -- rxy withcolor boxlinecolor withpen pencircle scaled boxgridwidth ;
+enddef ;
+
+def draw_par  = % 1 2 3 11 12
+  do_draw_par(pxy) ; do_draw_par(txy) ; do_draw_par(bxy) ;
+  for i = pxy, txy, bxy :
+        if boxgridtype= 1 :
+      boxgriddirection := origin ;
+      draw baseline_grid (i,boxgriddirection,true ) withcolor boxgridcolor ;
+    elseif boxgridtype= 2 :
+      boxgriddirection := origin ;
+      draw baseline_grid (i,boxgriddirection,false) withcolor boxgridcolor ;
+    elseif boxgridtype= 3 :
+      boxgriddirection := origin ;
+      draw baseline_grid (i,boxgriddirection,true ) withcolor boxgridcolor ;
+      draw baseline_grid (i,boxgriddirection,true )
+        shifted (0,ExHeight) withcolor boxgridcolor ;
+    elseif boxgridtype=11 :
+      draw graphic_grid(i,boxgriddistance,boxgriddistance,boxgriddistance/2,boxgriddistance/2) ;
+    elseif boxgridtype=12 :
+      draw graphic_grid(i,boxgriddistance,boxgriddistance,0,0) ;
+    fi ;
+  endfor ;
+enddef ;
+
+def do_show_par (expr p, r, c) =
+  if length(p) > 2 : for i=0 upto length(p) :
+    draw fullcircle scaled r shifted point i of p
+      withpen pencircle scaled .5pt withcolor c ;
+  endfor ; fi ;
+  draw p withpen pencircle scaled .5pt withcolor c ;
+enddef ;
+
+def show_par  =
+  if length(mxy) > 2 :
+    draw mxy dashed evenly
+      withpen pencircle scaled .5pt withcolor .5white ;
+  fi ;
+  do_show_par(txy, 4pt, .5green) ;
+  do_show_par(bxy, 6pt, .5blue ) ;
+  do_show_par(pxy, 8pt, .5red  ) ;
+  draw pref withpen pencircle scaled 2pt ;
+enddef ;
+
+def sort_multi_pars =
+  if nofmultipars>1 :
+    begingroup ; save _p_, _n_ ; path _p_ ; numeric _n_ ;
+      for i := 1 upto nofmultipars :
+        if multilocs[i] = 3 :
+          _p_ := multipars[nofmultipars] ;
+          multipars[nofmultipars] := multipars[i] ;
+          multipars[i] := _p_ ;
+          _n_ := multirefs[nofmultipars] ;
+          multirefs[nofmultipars] := multirefs[i] ;
+          multirefs[i] := _n_ ;
+          _n_ := multilocs[nofmultipars] ;
+          multilocs[nofmultipars] := multilocs[i] ;
+          multilocs[i] := _n_ ;
+        fi ;
+      endfor ;
+    endgroup ;
+  fi ;
+enddef ;
+
+% This collapses successive areas (possibly interrupted by
+% floats. First we need to sort the areas, since they are
+% normally in de order start, end, inbetween.
+
+def collapse_multi_pars =
+  if nofmultipars>1 :
+    begingroup ; save _nofmultipars_ ; numeric _nofmultipars_ ;
+    _nofmultipars_ := 1 ;
+    sort_multi_pars ; % block not in order: 1, 3, 2....
+    for i:=1 upto nofmultipars-1 :
+      if (round(xpart(llcorner multipars[i]-llcorner multipars[i+1]))=0) and
+         (round(xpart(lrcorner multipars[i]-lrcorner multipars[i+1]))=0) :
+multilocs[_nofmultipars_] := multilocs[i+1] ;
+multirefs[_nofmultipars_] := multirefs[i+1] ;
+        multipars[_nofmultipars_] :=
+          ulcorner multipars[_nofmultipars_] --
+          urcorner multipars[_nofmultipars_] --
+          lrcorner multipars[i+1] --
+          llcorner multipars[i+1] -- cycle ;
+      else :
+        _nofmultipars_ := _nofmultipars_ + 1 ;
+        multipars[_nofmultipars_] := multipars[i+1] ;
+        multilocs[_nofmultipars_] := multilocs[i+1] ;
+        multirefs[_nofmultipars_] := multirefs[i+1] ;
+      fi  ;
+    endfor ;
+    nofmultipars := _nofmultipars_ ;
+    endgroup ;
+  fi ;
+enddef ;
+
+def draw_multi_pars  =
+  for i=1 upto nofmultipars :
+    do_draw_par(multipars[i]) ;
+        if boxgridtype= 1 :
+      draw baseline_grid (multipars[i],up,true ) withcolor boxgridcolor ;
+    elseif boxgridtype= 2 :
+      draw baseline_grid (multipars[i],up,false) withcolor boxgridcolor ;
+    elseif boxgridtype= 3 :
+      draw baseline_grid (multipars[i],up,true ) withcolor boxgridcolor ;
+      draw baseline_grid (multipars[i],up,true )
+        shifted (0,ExHeight) withcolor boxgridcolor ;
+    elseif boxgridtype=11 :
+      draw graphic_grid(multipars[i],boxgriddistance,boxgriddistance,boxgriddistance/2,boxgriddistance/2) ;
+    elseif boxgridtype=12 :
+      draw graphic_grid(multipars[i],boxgriddistance,boxgriddistance,0,0) ;
+    fi ;
+  endfor ;
+enddef ;
+
+def show_multi_pars  =
+  for i=1 upto nofmultipars :
+    do_show_par(multipars[i], 6pt, .5blue) ;
+  endfor ;
+enddef ;
+
+vardef do_draw_par (expr p) =
+  if (length p>2) and (bbwidth(p)>1) and (bbheight(p)>1) :
+    save pp ; path pp ;
+    if (boxlineradius>0) and (boxlinetype=2) :
+      pp := p cornered boxlineradius ;
+    else :
+      pp := p ;
+    fi ;
+    if boxfilltype>0 :
+      if boxfilloffset>0 :
+        % temporary hack
+        begingroup ; interim linejoin := mitered ;
+          filldraw pp withcolor boxfillcolor withpen pencircle scaled (2*boxfilloffset) ;
+        endgroup ;
+      else :
+        fill pp withcolor boxfillcolor ;
+      fi ;
+    fi ;
+    if boxlinetype>0 :
+      draw pp withcolor boxlinecolor withpen pencircle scaled boxlinewidth ;
+    fi ;
+  fi ;
+enddef ;
+
+vardef baseline_grid (expr pxy, pdir, at_baseline) =
+  if (par_line_height>0) and (bbheight(pxy)>1) and (bbwidth(pxy)>1) and (boxgridwidth>0) :
+    save i, grid ; picture grid ; pair start ;
+    def _do_ (expr start) =
+      draw start -- start shifted (bbwidth(pxy),0)
+        withpen pencircle scaled boxgridwidth
+        withcolor boxgridcolor ;
+    enddef ;
+    grid := image
+      ( %fails with inlinespace
+        %
+        if pdir=up :
+          for i = if at_baseline : par_strut_depth else : 0 fi
+                  step  par_line_height
+                  until max(bbheight(pxy),par_line_height) :
+            _do_ (llcorner pxy shifted (0,+i)) ;
+          endfor ;
+        else :
+          for i = if at_baseline : par_strut_height else : 0 fi
+                  step  par_line_height
+                  until bbheight(pxy) :
+            _do_ (ulcorner pxy shifted (0,-i)) ;
+          endfor ;
+        fi ;
+      ) ;
+    clip grid to pxy ;
+    grid
+  else :
+    nullpicture
+  fi
+enddef ;
+
+vardef graphic_grid (expr pxy, dx, dy, x, y) =
+  if (bbheight(pxy)>dy) and (bbwidth(pxy)>dx) and (boxgridwidth>0) :
+    save grid ; picture grid ;
+    grid := image
+      ( for i = xpart llcorner pxy step dx until xpart lrcorner pxy :
+          draw (i,ypart llcorner pxy) -- (i,ypart ulcorner pxy)
+            withpen pencircle scaled boxgridwidth ;
+        endfor ;
+        for i = ypart llcorner pxy step dy until ypart ulcorner pxy :
+          draw (xpart llcorner pxy,i) -- (xpart lrcorner pxy,i)
+            withpen pencircle scaled boxgridwidth ;
+        endfor ) shifted (x,y) ;
+    clip grid to pxy ;
+    grid
+  else :
+    nullpicture
+  fi
+enddef ;
+
+def anchor_box (expr n,x,y,w,h,d) =
+  currentpicture := currentpicture shifted (-x,-y) ;
+enddef ;
+
+let draw_area   = draw_box ;
+let anchor_area = anchor_box ;
+let anchor_par  = anchor_box ;
+
+% new and experimental and yet undocumented
+
+numeric sync_n[], sync_p[][], sync_w[][], sync_h[][], sync_d[][], sync_t[][] ;
+pair sync_xy[][] ; color sync_c[][] ;
+
+def ResetSyncTasks =
+  path SyncPaths[] ; numeric SyncTasks[], NOfSyncPaths, CurrentSyncClass ;
+  NOfSyncPaths := CurrentSyncClass := 0 ;
+  if unknown SyncLeftOffset : numeric SyncLeftOffset ; SyncLeftOffset := 0          ; fi ;
+  if unknown SyncWidth      : numeric SyncWidth      ; SyncWidth      := 0          ; fi ;
+  if unknown SyncThreshold  : numeric SyncThreshold  ; SyncThreshold  := LineHeight ; fi ;
+  if unknown SyncColor      : color   SyncColor      ; SyncColor      := .5white    ; fi ;
+  if (SyncLeftOffset = 0) and (SyncWidth = 0) :
+    SyncWidth := if known TextWidth : TextWidth else : -1cm fi ;
+  fi ;
+enddef ;
+
+ResetSyncTasks ;
+
+vardef SyncBox(expr n, i, leftoffset, width, topoffset, bottomoffset) =
+   save o ; pair o ; o := (xpart llcorner PlainTextArea,ypart sync_xy[n][i]) ;
+   o shifted (leftoffset,sync_h[n][i]+topoffset) --
+   o shifted (width+leftoffset,sync_h[n][i]+topoffset) --
+   o shifted (width+leftoffset,bottomoffset) --
+   o shifted (leftoffset,bottomoffset) -- cycle
+enddef ;
+
+def SetSyncColor(expr n, i, c) =
+  sync_c[n][i] := c ;
+enddef ;
+
+def SetSyncThreshold(expr n, i, th) =
+  sync_th[n][i] := th ;
+enddef ;
+
+vardef TheSyncColor(expr n, i) =
+  if known sync_c[n][i] : sync_c[n][i] else : SyncColor fi
+enddef ;
+
+vardef TheSyncThreshold(expr n, i) =
+  if known sync_th[n][i] : sync_th[n][i] else : SyncThreshold fi
+enddef ;
+
+vardef PrepareSyncTasks(expr n, collapse, extendtop, prestartnext) =
+  ResetSyncTasks ;
+  if known sync_n[n] :
+    CurrentSyncClass := n ;
+    save ok, l, d ; boolean ok ; ok := false ; NOfSyncPaths := l := 0 ;
+    for i=1 upto sync_n[n] :
+      if RealPageNumber > sync_p[n][i] :
+        l := i ;
+      elseif RealPageNumber = sync_p[n][i] :
+        NOfSyncPaths := NOfSyncPaths + 1 ;
+        if not ok :
+          if i>1 :
+% not yet correct when two of the same follow each other
+            if sync_t[n][i-1] = sync_t[n][i] :
+              SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, PaperHeight, -PaperHeight) ;
+              SyncTasks[NOfSyncPaths] := i ;
+            else :
+              SyncPaths[NOfSyncPaths] := SyncBox(n, i-1, SyncLeftOffset, SyncWidth, PaperHeight, -PaperHeight) ;
+              SyncTasks[NOfSyncPaths] := i-1 ;
+              NOfSyncPaths := NOfSyncPaths + 1 ;
+              SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, 0, -PaperHeight) ;
+              SyncTasks[NOfSyncPaths] := i ;
+            fi ;
+          else :
+            SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, 0, -PaperHeight) ;
+            SyncTasks[NOfSyncPaths] := i ;
+          fi ;
+        else :
+          SyncPaths[NOfSyncPaths] := SyncBox(n, i, SyncLeftOffset, SyncWidth, 0, -PaperHeight) ;
+          SyncTasks[NOfSyncPaths] := i ;
+        fi ;
+        ok := true ;
+      fi ;
+    endfor ;
+    if (NOfSyncPaths = 0) and (l > 0) :
+      NOfSyncPaths := 1 ;
+      SyncPaths[NOfSyncPaths] := SyncBox(n, l, SyncLeftOffset, SyncWidth, PaperHeight, -PaperHeight) ;
+      SyncTasks[NOfSyncPaths] := l ;
+    fi ;
+    if NOfSyncPaths > 0 :
+      for i = 1 upto NOfSyncPaths-1 :
+        SyncPaths[i] := topboundary SyncPaths[i] -- reverse topboundary SyncPaths[i+1] -- cycle ;
+      endfor ;
+      if unknown SyncThresholdMethod :
+        numeric SyncThresholdMethod ; SyncThresholdMethod := 2 ;
+      fi ;
+      if extendtop :
+        if SyncThresholdMethod = 1 :
+          if NOfSyncPaths>1 :
+            d := ypart (ulcorner PlainTextArea - sync_xy[n][SyncTasks[2]]) ;
+            if (SyncTasks[2]>1) and (d > 0pt) and (d <= TheSyncThreshold(n,sync_t[n][SyncTasks[2]])) and (sync_p[n][SyncTasks[2]] = RealPageNumber) :
+              SyncPaths[2] := SyncPaths[2] topenlarged PaperHeight ;
+            fi ;
+          fi ;
+        else :
+          for i = 1 upto NOfSyncPaths :
+            d := ypart (ulcorner PlainTextArea - sync_xy[n][SyncTasks[i]]) ;
+            if (d > 0) and (d <= TheSyncThreshold(n,sync_t[n][SyncTasks[i]])) and (sync_p[n][SyncTasks[i]] = RealPageNumber) :
+              SyncPaths[i] := SyncPaths[i] topenlarged PaperHeight ;
+            fi ;
+          endfor ;
+        fi ;
+      fi ;
+      if prestartnext :
+        if NOfSyncPaths>1 :
+          if SyncTasks[NOfSyncPaths] < sync_n[n] : % there is a next one
+            d := ypart (ulcorner PlainTextArea - sync_xy[n][SyncTasks[NOfSyncPaths]+1]) ;
+            if (d > 0) and (d <= TheSyncThreshold(n, sync_t[n][SyncTasks[i]])) and (sync_p[n][SyncTasks[NOfSyncPaths]+1] = RealPageNumber+1) :
+              SyncPaths[NOfSyncPaths+1] :=
+                (xpart ulcorner SyncPaths[NOfSyncPaths],ypart llcorner PlainTextArea) --
+                (xpart urcorner SyncPaths[NOfSyncPaths],ypart llcorner PlainTextArea) --
+                lrcorner SyncPaths[NOfSyncPaths] --
+                llcorner SyncPaths[NOfSyncPaths] -- cycle ;
+              SyncTasks[NOfSyncPaths+1] := SyncTasks[NOfSyncPaths]+1 ;
+              NOfSyncPaths := NOfSyncPaths + 1 ;
+            fi ;
+          fi ;
+        fi ;
+      else :
+        if NOfSyncPaths>1 :
+          d := ypart (sync_xy[n][SyncTasks[NOfSyncPaths]] - llcorner PlainTextArea) ;
+          if (d < TheSyncThreshold(n, SyncTasks[NOfSyncPaths])) :
+            NOfSyncPaths := NOfSyncPaths - 1 ;
+            SyncPaths[NOfSyncPaths] := SyncPaths[NOfSyncPaths] bottomenlarged PaperHeight ;
+          fi ;
+        fi ;
+      fi ;
+      if (NOfSyncPaths>1) and collapse :
+        save j ; numeric j ; j := 1 ;
+        for i = 2 upto NOfSyncPaths :
+          if sync_t[n][SyncTasks[i]] = sync_t[n][SyncTasks[j]] :
+            SyncPaths[j] := boundingbox image (draw SyncPaths[i] ; draw SyncPaths[j] ; ) ;
+            SyncTasks[j] := SyncTasks[i] ;
+          else :
+            j := j + 1 ;
+            SyncPaths[j] := SyncPaths[i] ;
+            SyncTasks[j] := SyncTasks[i] ;
+          fi ;
+        endfor ;
+        NOfSyncPaths := j ;
+      fi ;
+    fi ;
+  fi ;
+enddef ;
+
+def SyncTask(expr n) =
+  if known SyncTasks[n] : SyncTasks[n] else : 0 fi
+enddef ;
+
+def FlushSyncTasks =
+  for i = 1 upto NOfSyncPaths :
+    ProcessSyncTask(SyncPaths[i], TheSyncColor(CurrentSyncClass,sync_t[CurrentSyncClass][SyncTasks[i]])) ;
+  endfor ;
+enddef ;
+
+def ProcessSyncTask(expr p, c) =
+  fill p withcolor c ;
+enddef ;
+
+endinput ;
\ No newline at end of file
diff --git a/Master/texmf-dist/metapost/context/base/mp-figs.mp b/Master/texmf-dist/metapost/context/base/mp-figs.mp
new file mode 100644
index 00000000000..aa6bc0399fb
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-figs.mp
@@ -0,0 +1,50 @@
+%D \module
+%D   [       file=mp-tool.mp,
+%D        version=2003.01.15,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=figures,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_figs : endinput         ; fi ;
+
+boolean context_figs ; context_figs := true ;
+
+% todo: check defined
+
+def registerfigure(expr name,width,height) =
+  begingroup ;
+  save s ; string s ; s := cleanstring(name) ;
+  scantokens( s & "_width := " & decimal(width)) ;
+  scantokens( s & "_height := " & decimal(width)) ;
+  endgroup ;
+enddef ;
+
+vardef figuresize(expr name) =
+  save s ; string s ; s := cleanstring(name) ;
+  save p ; pair p ;
+  scantokens( "p := " & "(" & s & "_width" & "," & s & "_height" & ")" ) ;
+  p
+enddef ;
+
+vardef figurewidth(expr name) =
+  xpart figuresize(name)
+enddef ;
+
+vardef figureheight(expr name) =
+  ypart figuresize(name)
+enddef ;
+
+def figuredimensions = figuresize enddef ; % for old times sake
+
+def naturalfigure(expr name) =
+    externalfigure name xyscaled(figuresize(name))
+enddef ;
+
+endinput
diff --git a/Master/texmf-dist/metapost/context/base/mp-fobg.mp b/Master/texmf-dist/metapost/context/base/mp-fobg.mp
new file mode 100644
index 00000000000..712efe751aa
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-fobg.mp
@@ -0,0 +1,88 @@
+%D \module
+%D   [       file=mp-fobg.mp,
+%D        version=2004.03.12,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=Formatting Objects,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_fobg : endinput         ; fi ;
+
+boolean context_fobg ; context_fobg := true ;
+
+FoNone   := 0 ; FoHidden := 1 ; FoDotted := 2 ; FoDashed := 3 ; FoSolid  := 4 ;
+FoDouble := 5 ; FoGroove := 6 ; FoRidge  := 7 ; FoInset  := 8 ; FoOutset := 9 ;
+FoAll    := 0 ; FoTop    := 1 ; FoBottom := 2 ; FoLeft   := 3 ; FoRight  := 4 ;
+FoMedium := .5pt ; FoThin := FoMedium/2 ; FoThick := FoMedium*2 ;
+
+color FoBackgroundColor, FoNoColor, FoLineColor[] ; FoNoColor := (-1,-1,-1) ;
+numeric FoLineWidth[], FoLineStyle[] ;
+boolean FoFrame, FoBackground, FoSplit ;
+
+FoFrame := FoBackground := FoSplit := false ;
+FoBackgroundColor := white ;
+FoDashFactor := .5 ;
+FoDotFactor := .375 ;
+
+for i = FoAll upto FoRight :
+  FoLineColor[i] := black ;
+  FoLineWidth[i] := .5pt ;
+  FoLineStyle[i] := FoNone ;
+endfor ;
+
+def DrawFoFrame(expr n, p) =
+  drawoptions(withcolor FoLineColor[n] withpen pencircle scaled FoLineWidth[n]) ;
+  if     FoLineStyle[n] = FoNone   :
+    % nothing
+  elseif FoLineStyle[n] = FoHidden :
+    % nothing
+  elseif FoLineStyle[n] = FoDotted :
+    draw p dashed (withdots scaled (FoDotFactor*FoLineWidth[n])) ;
+  elseif FoLineStyle[n] = FoDashed :
+    draw p dashed (evenly scaled (FoDashFactor*FoLineWidth[n])) ;
+  elseif FoLineStyle[n] = FoSolid  :
+    draw p ;
+  elseif FoLineStyle[n] = FoDouble :
+    draw p enlarged  FoLineWidth[n] ; draw p enlarged -FoLineWidth[n] ;
+  elseif FoLineStyle[n] = FoGroove :
+    draw p ;
+    draw p withpen pencircle scaled .5FoLineWidth[n] withcolor (inverted FoLineColor[n] softened .5) ;
+  elseif FoLineStyle[n] = FoRidge  :
+    draw p withcolor  (inverted FoLineColor[n] softened .5) ;
+    draw p withpen pencircle scaled .5FoLineWidth[n] ;
+  elseif FoLineStyle[n] = FoInset  :
+    draw p ; draw p inset 2.5FoLineWidth[n] ;
+  elseif FoLineStyle[n] = FoOutset :
+    draw p ; draw p outset 2.5FoLineWidth[n] ;
+ fi ;
+enddef ;
+
+primarydef p outset d =
+  ((lrcorner p -- urcorner p -- ulcorner p -- llcorner p -- cycle)
+      shifted (d*(-1,1)) cutbefore topboundary p) cutafter leftboundary p
+enddef ;
+
+primarydef p inset d =
+  ((ulcorner p -- llcorner p -- lrcorner p -- urcorner p -- cycle)
+      shifted (d*(1,-1)) cutbefore bottomboundary p) cutafter rightboundary p
+enddef ;
+
+vardef equalpaths(expr p, q) =
+  if length(p) = length(q) :
+    save ok ; boolean ok ; ok := true ;
+    for i = 0 upto length(p)-1 :
+      ok := ok and (round(point i of p) = round(point i of q)) ;
+    endfor ;
+    ok
+  else :
+    false
+  fi
+enddef ;
+
+endinput ;
diff --git a/Master/texmf-dist/metapost/context/base/mp-form.mp b/Master/texmf-dist/metapost/context/base/mp-form.mp
new file mode 100644
index 00000000000..bad87651c17
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-form.mp
@@ -0,0 +1,397 @@
+% Hans Hagen / October 2000  
+%
+% This file is mostly a copy from the file format.mp, that 
+% comes with MetaPost and is written by John Hobby. This file 
+% is meant to be compatible, but has a few more features, 
+% controlled by the variables: 
+%
+% fmt_initialize  when false, initialization is skipped
+% fmt_precision   the default accuracy (default=3)
+% fmt_separator   the pattern separator (default=%)
+% fmt_zerocheck   activate extra sci notation zero check 
+%
+% instead of a picture, one can format a number in a for TeX
+% acceptable input string
+
+boolean mant_font ; mant_font := true ; % signals graph not to load form 
+
+if   known fmt_loaded : expandafter endinput fi ; 
+   boolean fmt_loaded ; fmt_loaded := true ;
+
+if unknown fmt_precision : 
+   numeric fmt_precision ; fmt_precision := 3 ; 
+fi ;
+
+if unknown fmt_initialize : 
+   boolean fmt_initialize ; fmt_initialize := true ; 
+fi ; 
+
+if unknown fmt_separator : 
+    string fmt_separator ; fmt_separator := "%" ; 
+fi ; 
+
+if unknown fmt_zerocheck : 
+   boolean fmt_zerocheck ; fmt_zerocheck := false ; 
+fi ; 
+
+boolean fmt_metapost ; fmt_metapost := true ; % == use old method 
+
+% As said, all clever code is from John, the more stupid 
+% extensions are mine. The following string variables are 
+% responsible for the TeX formatting. 
+
+% TeX specs when using TeX instead of pseudo TeX. 
+
+string sFebraise_ ; sFebraise_ := "{" ; 
+string sFeeraise_ ; sFeeraise_ := "}" ; 
+string sFebmath_  ; sFebmath_  := "$" ; 
+string sFeemath_  ; sFeemath_  := "$" ; 
+
+string sFmneg_    ; sFmneg_    := "-" ; 
+string sFemarker_ ; sFemarker_ := "{\times}10^" ; 
+string sFeneg_    ; sFeneg_    := "-" ; 
+string sFe_plus   ; sFe_plus   := "" ; % "+" 
+
+def sFe_base = Fline_up_("1", sFemarker_) enddef ; 
+
+% Macros for generating typeset pictures of computed numbers
+%
+% format(f,x)               typeset generalized number x using format string f
+% Mformat(f,x)              like format, but x is in Mlog form (see marith.mp)
+% init_numbers(s,m,x,sn,e)  choose typeset style given sample sign, mantissa,...
+% roundd(x,d)               round numeric x to d places right of decimal point
+% Fe_base                   what precedes the exponent for typeset powers of 10
+% Fe_plus                   plus sign if any for typesetting positive exponents
+% Ten_to[]                  powers of ten for indices 0,1,2,3,4
+%
+% New are: 
+%
+% formatstr(f,x)            TeX string representing x using format f
+% Mformatstr(f,x)           like Mformatstr, but x is in Mlog form
+
+% Other than the above-documented user interface, all
+% externally visible names start with F and end with _. 
+
+% Allow big numbers in token lists
+
+begingroup interim warningcheck := 0 ; 
+
+%%% Load auxiliary macros. 
+
+input string
+input marith
+
+%%% Choosing the Layout %%%
+
+picture Fmneg_, Femarker_, Feneg_, Fe_base, Fe_plus ;
+string  Fmfont_, Fefont_ ;
+numeric Fmscale_, Fescale_, Feraise_ ;
+
+% Argument 
+%
+% s   is a leading minus sign
+% m   is a 1-digit mantissa
+% x   is whatever follows the mantissa 
+% sn  is a leading minus for the exponent, and  
+% e   is a 1-digit exponent. 
+% 
+% Numbers in scientific notation are constructed by placing
+% these pieces side-by-side; decimal numbers use only m
+% and/or s. To get exponents with leading plus signs, assign
+% to Fe_plus after calling init_numbers. To do something
+% special with a unit mantissa followed by x, assign to
+% Fe_base after calling init_numbers. 
+
+vardef init_numbers(expr s, m, x, sn, e) = 
+  Fmneg_ := s ;
+  for p within m : 
+    Fmfont_ := fontpart p ;
+    Fmscale_ := xxpart p ;
+    exitif true ;
+  endfor
+  Femarker_ := x ;
+  Feneg_ := sn ;
+  for p within e :
+    Fefont_ := fontpart p ;
+    Fescale_ := xxpart p ;
+    Feraise_ := ypart llcorner p ;
+    exitif true ;
+  endfor
+  if fmt_metapost : 
+    Fe_base := Fline_up_("1" infont Fmfont_ scaled Fmscale_, Femarker_) ;
+  % else : 
+  %   sFe_base := Fline_up_("1", sFemarker_) ;
+  fi ; 
+  Fe_plus := nullpicture ;
+enddef ;
+
+%%% Low-Level Typesetting %%%
+
+vardef Fmant_(expr x) = %%% adapted by HH %%%
+  if fmt_metapost : 
+    (decimal abs x infont Fmfont_ scaled Fmscale_)
+  else : 
+    (decimal abs x) 
+  fi 
+enddef ;
+
+vardef Fexp_(expr x) = %%% adapted by HH %%%
+  if fmt_metapost : 
+    (decimal x infont Fefont_ scaled Fescale_ shifted (0,Feraise_))
+  else : 
+    (decimal x) 
+  fi 
+enddef ;
+
+vardef Fline_up_(text t_) = %%% adapted by HH %%%
+  if fmt_metapost : 
+    save p_, c_ ;
+    picture p_ ; p_ = nullpicture ;
+    pair c_ ; c_ = (0,0) ;
+    for q_ = t_ :
+      addto p_ also q_ if string q_ : infont defaultfont scaled defaultscale fi
+          shifted c_ ;
+      c_ := (xpart lrcorner p_, 0) ;
+    endfor
+    p_
+  else : 
+    "" for q_ = t_ : & q_ endfor 
+  fi 
+enddef ;
+
+vardef Fdec_o_(expr x) = %%% adapted by HH %%%
+  if x<0 : 
+    Fline_up_(if fmt_metapost : Fmneg_ else : sFmneg_ fi, Fmant_(x))
+  else : 
+    Fmant_(x)
+  fi
+enddef ;
+
+vardef Fsci_o_(expr x, e) = %%% adapted by HH %%%
+  if fmt_metapost : 
+    Fline_up_
+      (if x < 0 : Fmneg_,fi
+       if abs x = 1 : Fe_base else : Fmant_(x), Femarker_ fi,
+       if e < 0 : Feneg_ else : Fe_plus fi,
+       Fexp_(abs e)) 
+  else : 
+    Fline_up_
+      (if x < 0 : sFmneg_, fi
+       if abs x = 1 : sFe_base else : Fmant_(x), sFemarker_ fi,
+       sFebraise_, 
+       if e < 0 : sFeneg_ else : sFe_plus fi,
+       Fexp_(abs e), 
+       sFeeraise_)
+   fi 
+enddef ;
+
+% Assume prologues=1 implies troff mode. TeX users who want
+% prologues on should use some other positive value. The mpx
+% file mechanism requires separate input files here. 
+
+if fmt_initialize : %%% adapted by HH 
+  if prologues = 1 : input troffnum else : input texnum fi
+fi ;
+
+%%% Scaling and Rounding %%%
+
+% Find a pair p where x = xpart p*10**ypart p and either p =
+% (0,0) or xpart p is between 1000 and 9999.99999. This is
+% the `exponent form' of x. 
+
+vardef Feform_(expr x) = 
+  interim warningcheck := 0 ;
+  if string x :
+    Meform(Mlog_str x)
+  else :
+    save b, e ;
+    b = x ; e = 0 ;
+    if abs b >= 10000 : 
+      (b/10, 1)
+    elseif b = 0 : 
+      origin
+    else : 
+      forever :
+        exitif abs b >= 1000 ;
+        b := b*10 ; e := e-1 ;
+      endfor
+      (b, e)
+    fi
+  fi
+enddef ;
+
+% The marith.mp macros include a similar macro Meform that
+% converts from `Mlog form' to exponent form. In case
+% rounding has made the xpart of an exponent form number too
+% large, fix it. 
+
+vardef Feadj_(expr x, y) = 
+  if abs x >= 10000 : (x/10, y+1) else : (x,y) fi
+enddef ;
+
+% Round x to d places right of the decimal point. When d<0,
+% round to the nearest multiple of 10 to the -d. 
+
+vardef roundd(expr x, d) = 
+  if abs d > 4 :
+    if d > 0 : x else : 0 fi
+  elseif d > 0 :
+    save i ; i = floor x ;
+    i + round(Ten_to[d]*(x-i))/Ten_to[d]
+  else :
+    round(x/Ten_to[-d])*Ten_to[-d]
+  fi
+enddef ;
+
+Ten_to0 =     1 ; 
+Ten_to1 =    10 ; 
+Ten_to2 =   100 ; 
+Ten_to3 =  1000 ; 
+Ten_to4 = 10000 ;
+
+% Round an exponent form number p to k significant figures. 
+
+primarydef p Fprec_ k = 
+  Feadj_(roundd(xpart p,k-4), ypart p)  
+enddef ;
+
+% Round an exponent form number p to k digits right of the
+% decimal point. 
+
+primarydef p Fdigs_ k = 
+  Feadj_(roundd(xpart p,k+ypart p), ypart p)  
+enddef ;
+
+%%% High-Level Routines %%%
+
+% The following operators convert z from exponent form and
+% produce typeset output: Formsci_ generates scientific
+% notation; Formdec_ generates decimal notation; and
+% Formgen_ generates whatever is likely to be most compact. 
+
+vardef Formsci_(expr z) = %%% adapted by HH %%%
+  if fmt_zerocheck and (z = origin) : 
+    Fsci_o_(0,0)  
+  else : 
+    Fsci_o_(xpart z/1000, ypart z + 3)  
+  fi 
+enddef ;
+
+vardef Formdec_(expr z) = 
+  if ypart z > 0 : 
+    Formsci_(z)
+  else :
+    Fdec_o_
+      (xpart z if ypart z >= -4 : 
+                 /Ten_to[-ypart z]
+               else : 
+                 for i = ypart z upto -5 : /(10) endfor /10000 
+               fi)
+  fi
+enddef ;
+
+vardef Formgen_(expr q) = 
+  clearxy ; (x,y) = q ;
+  if     x  =  0 : Formdec_
+  elseif y >= -6 : Formdec_
+  else           : Formsci_
+  fi (q)
+enddef ;
+
+def Fset_item_(expr s) = %%% adapted by HH %%%
+  if s <> "" :  
+    if fmt_metapost :
+      s infont defaultfont scaled defaultscale,
+    else : 
+      s, 
+    fi 
+  fi 
+enddef ;
+
+% For each format letter, the table below tells how to
+% round and typeset a quantity z in exponent form. 
+%
+% e  scientific, p significant figures
+% p  decimal, p digits right of the point
+% g  decimal or scientific, p sig. figs.
+% G  decimal or scientific, p digits
+
+string fmt_[] ;
+
+fmt_[ASCII "e"] = "Formsci_(z Fprec_ p)" ; 
+fmt_[ASCII "f"] = "Formdec_(z Fdigs_ p)" ;
+fmt_[ASCII "g"] = "Formgen_(z Fprec_ p)" ; 
+fmt_[ASCII "G"] = "Formgen_(z Fdigs_ p)" ; 
+
+% The format and Mformat macros take a format string f and
+% generate typeset output for a numeric quantity x. String f
+% should contain a `%' followed by an optional number and one
+% of the format letters defined above. The number should be
+% an integer giving the precision (default 3). 
+
+vardef isfmtseparator primary c = %%% added by HH %%%
+  ((c <> fmt_separator) and (c <> "%")) 
+enddef ; 
+
+def initialize_form_numbers = 
+  initialize_numbers ; % in context: do_initialize_numbers ;
+enddef ;
+
+vardef dofmt_@#(expr f, x) = %%% adapted by HH %%%
+  initialize_form_numbers ; 
+  if f = "" : 
+    if fmt_metapost : nullpicture else : "" fi 
+  else :
+    interim warningcheck := 0 ;
+    save k, l, s, p, z ;
+    pair z ; z = @#(x) ;
+    % the next adaption is okay 
+    % k = 1 + cspan(f, fmt_separator <> ) ;
+    % but best is to support both % and fmt_separator 
+    k = 1 + cspan(f, isfmtseparator) ;
+    % 
+    l-k = cspan(substring(k,infinity) of f, isdigit) ;
+    p = if l > k :  
+      scantokens substring(k,l) of f  
+    else : 
+      fmt_precision 
+    fi ;
+    string s ; s = fmt_[ASCII substring (l,l+1) of f] ;
+    if unknown s :
+      if k <= length f : 
+        errmessage("No valid format letter found in "&f) ; 
+      fi
+      s = if fmt_metapost : "nullpicture" else : "" fi ;
+    fi
+    Fline_up_
+      (Fset_item_(substring (0,k-1) of f)
+       if not fmt_metapost : sFebmath_, fi 
+       scantokens s,
+       if not fmt_metapost : sFeemath_, fi 
+       Fset_item_(substring (l+1,infinity) of f)
+       if fmt_metapost : nullpicture else : "" fi) 
+  fi
+  hide (fmt_metapost := true) 
+enddef ;
+
+%%% so far %%% 
+
+vardef format (expr f, x) = 
+  fmt_metapost := true ; dofmt_.Feform_(f,x) 
+enddef ;
+
+vardef Mformat(expr f, x) = 
+  fmt_metapost := true ; dofmt_.Meform (f,x) 
+enddef ;
+
+vardef formatstr (expr f, x) = 
+  fmt_metapost := false ; dofmt_.Feform_(f,x) 
+enddef ;
+
+vardef Mformatstr(expr f, x) = 
+  fmt_metapost := false ; dofmt_.Meform (f,x) 
+enddef ;
+
+% Restore warningcheck to previous value.
+
+endgroup ; 
diff --git a/Master/texmf-dist/metapost/context/base/mp-func.mp b/Master/texmf-dist/metapost/context/base/mp-func.mp
new file mode 100644
index 00000000000..d8646ef3bdd
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-func.mp
@@ -0,0 +1,59 @@
+%D \module
+%D   [       file=mp-func.mp,
+%D        version=2001.12.29,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=function hacks, 
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for 
+%C details. 
+
+%D Under construction.
+
+if unknown context_tool :    input mp-tool ; fi ; 
+if   known context_func : endinput         ; fi ; 
+
+boolean context_func ; context_func := true ; 
+
+string pathconnectors[] ; 
+
+pathconnectors[0] := ","   ;
+pathconnectors[1] := "--"  ; 
+pathconnectors[2] := ".."  ; 
+pathconnectors[3] := "..." ; 
+
+vardef function (expr f) (expr u, t, b, e, s) = save x ; numeric x ; 
+  for xx := b step s until e : 
+    hide (x := xx ;) if xx>b : scantokens(pathconnectors[f]) fi 
+    (scantokens(u),scantokens(t)) 
+  endfor 
+enddef ; 
+
+def punkedfunction = function (1) enddef ; 
+def curvedfunction = function (2) enddef ; 
+def tightfunction  = function (3) enddef ; 
+
+vardef constructedpath (expr f) (text t) = 
+  save ok ; boolean ok ; ok := false ; 
+  for i=t : 
+    if ok : scantokens(pathconnectors[f]) else : ok := true ; fi i 
+  endfor  
+enddef ; 
+
+def punkedpath = constructedpath (1) enddef ;  
+def curvedpath = constructedpath (2) enddef ;  
+def tightpath  = constructedpath (3) enddef ;  
+
+vardef constructedpairs (expr f) (text p) = 
+  save i ; i := -1 ; 
+  forever : exitif unknown p[incr(i)] ; 
+    if i>0 : scantokens(pathconnectors[f]) fi p[i] 
+  endfor  
+enddef ; 
+
+def punkedpairs = constructedpairs (1) enddef ;  
+def curvedpairs = constructedpairs (2) enddef ;  
+def tightpairs  = constructedpairs (3) enddef ;  
diff --git a/Master/texmf-dist/metapost/context/base/mp-grid.mp b/Master/texmf-dist/metapost/context/base/mp-grid.mp
new file mode 100644
index 00000000000..f6e84348915
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-grid.mp
@@ -0,0 +1,145 @@
+%D \module
+%D   [       file=mp-grid.mp,
+%D        version=2000.07.10,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=grid support,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+%D Under construction.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_grid : endinput         ; fi ;
+
+boolean context_grid ; context_grid := true ;
+
+string  fmt_separator  ; fmt_separator  := "@" ;
+numeric fmt_precision  ; fmt_precision  := 3 ;
+boolean fmt_initialize ; fmt_initialize := false ;
+boolean fmt_zerocheck  ; fmt_zerocheck  := true ;
+
+if unknown fmt_loaded : input mp-form ; fi ;
+
+boolean fmt_pictures ; fmt_pictures := true ;
+
+def  do_format = if fmt_pictures :  format else :  formatstr fi enddef ;
+def do_mformat = if fmt_pictures : Mformat else : Mformatstr fi enddef ;
+
+numeric grid_eps ; grid_eps = eps ;
+
+def hlingrid (expr Min, Max, Step, Length, Width) text t =
+  image ( for i=Min step Step until Max+grid_eps :
+    draw (origin--(Width,0)) shifted (0,i*(Length/Max)) t ;
+  endfor ; ) ;
+enddef ;
+
+def vlingrid (expr Min, Max, Step, Length, Height) text t =
+  image ( for i=Min step Step until Max+grid_eps :
+    draw (origin--(0,Height)) shifted (i*(Length/Max),0) t ;
+  endfor ; ) ;
+enddef ;
+
+def hloggrid (expr Min, Max, Step, Length, Width) text t =
+  image ( for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw (origin--(Width,0)) shifted (0,Length*log(i)) t ;
+  endfor ; ) ;
+enddef ;
+
+def vloggrid (expr Min, Max, Step, Length, Height) text t =
+  image ( for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw (origin--(0,Height)) shifted (Length*log(i),0) t ;
+  endfor ; ) ;
+enddef ;
+
+vardef hlintext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=Min step Step until Max+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (0,i*(Length/Max)) t ;
+  endfor ; )
+enddef ;
+
+vardef vlintext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=Min step Step until Max+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (i*(Length/Max),0) t ;
+  endfor ; )
+enddef ;
+
+vardef hlogtext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (0,Length*log(i)) t ;
+  endfor ; )
+enddef ;
+
+vardef vlogtext@#(expr Min, Max, Step, Length, Format) text t =
+  image ( do_initialize_numbers ;
+  for i=max(Min,1) step Step until min(Max,10)+grid_eps :
+    draw textext@#(do_format(Format,i)) shifted (Length*log(i),0) t ;
+  endfor ; )
+enddef ;
+
+vardef hlinlabel@#(expr Min, Max, Step, Length) text t =
+  image (
+  for i=Min step Step until Max+grid_eps :
+    draw thelabel@#(decimal i,(0,i*(Length/Max))) t ;
+  endfor ; )
+enddef ;
+
+vardef vlinlabel@#(expr Min, Max, Step, Length) text t =
+  image (
+  for i=Min step Step until Max+grid_eps :
+    draw thelabel@#(decimal i,(i*(Length/Max),0)) t ;
+  endfor ; )
+enddef ;
+
+boolean numbers_initialized ; numbers_initialized := false ;
+
+def do_initialize_numbers =
+  if not numbers_initialized :
+    init_numbers ( textext.raw("$-$")          ,
+                   textext.raw("$1$")          ,
+                   textext.raw("${\times}10$") ,
+                   textext.raw("${}^-$")       ,
+                   textext.raw("${}^2$")       ) ;
+    numbers_initialized := true ;
+  fi ;
+enddef ;
+
+def initialize_numbers =
+  numbers_initialized := false ; do_initialize_numbers ;
+enddef ;
+
+vardef linlog(expr xy) = (    xpart xy,  log(ypart xy)) enddef ;
+vardef loglin(expr xy) = (log(xpart xy),     ypart xy)  enddef ;
+vardef loglog(expr xy) = (log(xpart xy), log(ypart xy)) enddef ;
+vardef linlin(expr xy) = (   (xpart xy),    (ypart xy)) enddef ;
+
+vardef loglinpath primary p = processpath (p) (loglin) enddef ;
+vardef linlogpath primary p = processpath (p) (linlog) enddef ;
+vardef loglogpath primary p = processpath (p) (loglog) enddef ;
+vardef linlinpath primary p = processpath (p) (linlin) enddef ;
+
+def processpath (expr p) (text pp) =
+  if path p :
+    for i=0 upto length(p)-1 :
+      (pp(point       i    of p)) .. controls
+      (pp(postcontrol i    of p)) and
+      (pp(precontrol (i+1) of p)) ..
+    endfor
+    if cycle p :
+      cycle
+    else :
+      (pp(point length(p) of p))
+    fi
+  elseif pair p :
+    (pp(p))
+  else :
+    p
+  fi
+enddef ;
diff --git a/Master/texmf-dist/metapost/context/base/mp-grph.mp b/Master/texmf-dist/metapost/context/base/mp-grph.mp
new file mode 100644
index 00000000000..18c43c57b53
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-grph.mp
@@ -0,0 +1,295 @@
+%D \module
+%D   [       file=mp-grph.mp,
+%D        version=2000.12.14,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=graphic text support,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+%D Under construction.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_grph : endinput         ; fi ;
+
+boolean context_grph ; context_grph := true ;
+
+string CRLF ; CRLF := char 10 & char 13 ;
+
+picture _currentpicture_ ;
+
+def beginfig (expr c) =
+  begingroup
+  charcode := c ;
+  resetfig ;
+  scantokens extra_beginfig ;
+enddef ;
+
+def resetfig =
+  clearxy ;
+  clearit ;
+  clearpen ;
+  pickup defaultpen ;
+  interim linecap := linecap ;
+  interim linejoin := linejoin ;
+  interim miterlimit := miterlimit ;
+  save _background_ ; color _background_ ; _background_ :=  background  ;
+  save  background  ; color  background  ;  background  := _background_ ;
+  drawoptions () ;
+enddef ;
+
+def protectgraphicmacros =
+  save showtext ;
+  save beginfig ; let beginfig = begingraphictextfig ;
+  save endfig   ; let endfig   = endgraphictextfig ;
+  save end      ; let end      = relax ;
+  interim prologues := prologues ;
+  resetfig ; % resets currentpicture
+enddef ;
+
+numeric currentgraphictext ; currentgraphictext := 0 ;
+string  graphictextformat  ; graphictextformat  := "plain" ;
+string  graphictextstring  ; graphictextstring  := "" ;
+string  graphictextfile    ; graphictextfile    := "dummy.mpo" ;
+
+def savegraphictext (expr str) =
+  graphictextfile := jobname & ".mpo" ;
+  if (graphictextstring<>"") :
+    write graphictextstring to graphictextfile ;
+    graphictextstring := "" ;
+  fi ;
+  write str to graphictextfile ;
+  let erasegraphictextfile = relax ;
+enddef ;
+
+def erasegraphictextfile =
+  graphictextfile := jobname & ".mpo" ;
+  write EOF to graphictextfile  ;
+  let erasegraphictextfile = relax ;
+enddef ;
+
+extra_beginfig := extra_beginfig & " erasegraphictextfile ;" ;
+
+def begingraphictextfig (expr n) =
+  foundpicture := n ; scratchpicture := nullpicture ;
+enddef ;
+
+def endgraphictextfig =
+  if foundpicture = currentgraphictext :
+    expandafter endinput
+  else :
+    scratchpicture := nullpicture ;
+  fi ;
+enddef ;
+
+def loadfigure primary filename =
+  doloadfigure (filename)
+enddef ;
+
+def doloadfigure (expr filename) text figureattributes =
+  begingroup ;
+  save figurenumber, figurepicture, number, fixedplace ;
+  numeric figurenumber  ; figurenumber  := 0 ;
+  boolean figureshift ; figureshift := true ;
+  picture figurepicture ; figurepicture := currentpicture ;
+  def number primary n = hide(figurenumber := n) enddef ;
+  def fixedplace = hide(figureshift := false) enddef ;
+  protectgraphicmacros ;
+  % defaults
+  interim linecap    := rounded ;
+  interim linejoin   := rounded ;
+  interim miterlimit := 10 ;
+  %
+  currentpicture := nullpicture ;
+  draw fullcircle figureattributes ; % expand number
+  currentpicture := nullpicture ;
+  def beginfig (expr n) =
+    currentpicture := nullpicture ;
+    if (figurenumber=n) or (figurenumber=0) :
+      let endfig = endinput ;
+    fi ;
+  enddef ;
+  let endfig = relax ;
+  readfile(filename) ;
+  if figureshift :
+    currentpicture := currentpicture shifted -llcorner currentpicture ;
+  fi ;
+  addto figurepicture also currentpicture figureattributes ;
+  currentpicture := figurepicture  ;
+  endgroup ;
+enddef ;
+
+def graphictext primary t =
+  dographictext(t)
+enddef ;
+
+def dographictext (expr t) =
+  begingroup ;
+  save figurepicture ; picture figurepicture ;
+  figurepicture := currentpicture ; currentpicture := nullpicture ;
+  if graphictextformat<>"" :
+    graphictextstring :=
+      "% format=" & graphictextformat & CRLF & graphictextstring ;
+    graphictextformat := "" ;
+  fi ;
+  currentgraphictext := currentgraphictext + 1 ;
+  savegraphictext ("\startTEXpage[scale=10000]" & t & "\stopTEXpage") ;
+  dofinishgraphictext
+enddef ;
+
+def redographictext primary t =
+  regraphictext(t)
+enddef ;
+
+def regraphictext (expr t) =
+  begingroup ;
+  save figurepicture ; picture figurepicture ;
+  figurepicture := currentpicture ; currentpicture := nullpicture ;
+  save currentgraphictext ; numeric currentgraphictext ;
+  currentgraphictext := t ;
+  dofinishgraphictext
+enddef ;
+
+%D Believe it or not, but it took me half a day to uncover
+%D the following neccessity:
+%D
+%D \starttypen
+%D save withfillcolor, withdrawcolor ;
+%D \stoptypen
+%D
+%D When we have more than one graphictext, these will be
+%D defined after the first graphic. For some obscure reason,
+%D this means that in the next graphic they will be called, but
+%D afterwards the data and boolean are not set. Don't ask me
+%D why.
+
+def dofinishgraphictext text x_op_x =
+  protectgraphicmacros ; % resets currentpicture
+  interim linecap    := butt ;     % normally rounded
+  interim linejoin   := mitered ;  % normally rounded
+  interim miterlimit := 10 ;       % todo
+  let normalwithshade = withshade ;
+  save foundpicture, scratchpicture, str ;
+  save fill, draw, withshade, reversefill, outlinefill ;
+  save withfillcolor, withdrawcolor ; % quite important
+  numeric foundpicture ; picture scratchpicture ; string str ;
+  def draw expr p =
+    % the first, naive implementation was:
+    %   addto scratchpicture doublepath p withpen currentpen ;
+    % but it is better to turn lines into fills
+    addto scratchpicture contour boundingbox
+      image (addto currentpicture doublepath p withpen currentpen) ;
+  enddef ;
+  def fill expr p =
+    addto scratchpicture contour p withpen currentpen ;
+  enddef ;
+  def f_op_f = enddef ; boolean f_color ; f_color := false ;
+  def d_op_d = enddef ; boolean d_color ; d_color := false ;
+  def s_op_s = enddef ; boolean s_color ; s_color := false ;
+  boolean reverse_fill ; reverse_fill := false ;
+  boolean outline_fill ; outline_fill := false ;
+  def reversefill =
+    hide(reverse_fill := true )
+  enddef ;
+  def outlinefill =
+    hide(outline_fill := true )
+  enddef ;
+  def withshade primary c =
+    hide(def s_op_s = normalwithshade c enddef ; s_color := true )
+  enddef ;
+  def withfillcolor primary c =
+    hide(def f_op_f = withcolor c enddef ; f_color := true )
+  enddef ;
+  def withdrawcolor primary c =
+    hide(def d_op_d = withcolor c enddef ; d_color := true )
+  enddef ;
+  scratchpicture := nullpicture ;
+  addto scratchpicture doublepath origin x_op_x ; % pre-roll
+  for i within scratchpicture : % Below here is a dirty tricky test!
+    if (urcorner dashpart i) = origin : outline_fill := false ; fi ;
+  endfor ;
+  scratchpicture := nullpicture ;
+  readfile(jobname & ".mpy") ;
+  scratchpicture := (scratchpicture shifted -llcorner scratchpicture) scaled (1/10) ;
+  if not d_color and not f_color : d_color := true ; fi
+  if s_color : d_color := false ; f_color := false ; fi ;
+  currentpicture := figurepicture ;
+  if d_color and not reverse_fill :
+    for i within scratchpicture :
+      if f_color and outline_fill :
+        addto currentpicture doublepath pathpart i _op_ x_op_x f_op_f
+          dashed nullpicture ;
+      fi ;
+      if filled i :
+        addto currentpicture doublepath pathpart i _op_ x_op_x d_op_d ;
+      fi ;
+    endfor ;
+  fi ;
+  if f_color :
+    for i within scratchpicture :
+      if filled i :
+        addto currentpicture contour pathpart i _op_ x_op_x f_op_f
+          withpen pencircle scaled 0 ;
+      fi ;
+    endfor ;
+  fi ;
+  if d_color and reverse_fill :
+    for i within scratchpicture :
+      if filled i :
+        addto currentpicture doublepath pathpart i _op_ x_op_x d_op_d ;
+      fi ;
+    endfor ;
+  fi ;
+  if s_color :
+    for i within scratchpicture :
+      if filled i :
+        addto currentpicture contour pathpart i _op_ x_op_x s_op_s ;
+      fi ;
+    endfor ;
+  else :
+    for i within scratchpicture :
+      if stroked i :
+        addto currentpicture doublepath pathpart i _op_ x_op_x d_op_d ;
+      fi ;
+    endfor ;
+  fi ;
+  endgroup ;
+enddef ;
+
+def resetgraphictextdirective =
+  graphictextstring := "" ;
+enddef ;
+
+def graphictextdirective text t =
+  graphictextstring := graphictextstring & t & CRLF ;
+enddef ;
+
+endinput
+
+% example
+
+input mp-grph ;
+
+  graphictextformat := "context" ;
+% graphictextformat := "plain" ;
+% graphictextformat := "latex" ; graphictextdirective "\documentclass[]{article}" ;
+
+beginfig (1) ;
+  graphictext
+    "\vbox{\hsize10cm \input tufte }"
+    scaled 8
+    withdrawcolor blue
+    withfillcolor red
+    withpen pencircle scaled 2pt ;
+endfig ;
+
+beginfig(1) ;
+  loadfigure "gracht.mp" rotated 20 ;
+  loadfigure "koe.mp" number 1 scaled 2 ;
+endfig ;
+
+end
diff --git a/Master/texmf-dist/metapost/context/base/mp-page.mp b/Master/texmf-dist/metapost/context/base/mp-page.mp
new file mode 100644
index 00000000000..e3750b55b75
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-page.mp
@@ -0,0 +1,447 @@
+%D \module
+%D   [       file=mp-page.mp,
+%D        version=1999.03.10,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=page enhancements,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+%D This module is rather preliminary and subjected to
+%D changes.
+
+if unknown context_tool : input mp-tool ; fi ;
+if   known context_page : endinput      ; fi ;
+
+boolean context_page ; context_page := true ;
+
+if unknown PageStateAvailable :
+  boolean PageStateAvailable ; PageStateAvailable := false ;
+fi ;
+
+if unknown OnRightPage :
+  boolean OnRightPage ; OnRightPage := true ;
+fi ;
+
+if unknown OnOddPage :
+  boolean OnOddPage ; OnOddPage := true ;
+fi ;
+
+if unknown InPageBody :
+  boolean InPageBody ; InPageBody := false ;
+fi ;
+
+def SaveTextAreas =
+  path    SavedTextAreas  []  ;
+  path    SavedTextColumns[]  ;
+  numeric NOfSavedTextAreas   ;
+  numeric NOfSavedTextColumns ;
+  for i=1 upto NOfTextAreas :
+    SavedTextAreas[i] := TextAreas[i] ;
+  endfor ;
+  for i=1 upto NOfTextColumns :
+    SavedTextColumns[i] := TextColumns[i] ;
+  endfor ;
+  NOfSavedTextAreas   := NOfTextAreas ;
+  NOfSavedTextColumns := NOfTextColumns ;
+enddef ;
+
+def ResetTextAreas =
+  path TextAreas[], TextColumns[] ;
+  numeric NOfTextAreas   ; NOfTextAreas   := 0 ;
+  numeric NOfTextColumns ; NOfTextColumns := 0 ;
+  numeric nofmultipars   ; nofmultipars   := 0 ;
+  TextAreas[0] := TextColumns[0] := origin -- cycle ;
+enddef ;
+
+ResetTextAreas ; SaveTextAreas ; ;
+
+def RegisterTextArea (expr x, y, w, h, d) =
+  begingroup ; save p ; path p ;
+    p := unitsquare xyscaled(w,h+d) shifted (x,y-d) ;
+    if NOfTextAreas>0 :
+      % if needed, concatenate areas
+      if (round(llcorner TextAreas[NOfTextAreas]) = round(ulcorner p)) and
+         (round(lrcorner TextAreas[NOfTextAreas]) = round(urcorner p)) :
+        p := ulcorner TextAreas[NOfTextAreas] --
+             urcorner TextAreas[NOfTextAreas] --
+             lrcorner p --
+             llcorner p --
+             cycle ;
+      else :
+        NOfTextAreas := NOfTextAreas + 1 ;
+      fi ;
+    else :
+      NOfTextAreas := NOfTextAreas + 1 ;
+    fi ;
+    TextAreas[NOfTextAreas] := p ;
+    if NOfTextColumns>0 :
+      if (round(xpart llcorner TextColumns[NOfTextColumns]) = round(xpart ulcorner p)) and
+         (round(xpart lrcorner TextColumns[NOfTextColumns]) = round(xpart urcorner p)) :
+        p := ulcorner TextColumns[NOfTextColumns] --
+             urcorner TextColumns[NOfTextColumns] --
+             lrcorner p --
+             llcorner p --
+             cycle ;
+      else :
+        NOfTextColumns := NOfTextColumns + 1 ;
+      fi ;
+    else :
+      NOfTextColumns := NOfTextColumns + 1 ;
+    fi ;
+    TextColumns[NOfTextColumns] := p ;
+  endgroup ;
+enddef ;
+
+%D We store a local area in slot zero.
+
+def RegisterLocalTextArea (expr x, y, w, h, d) =
+  TextAreas[0] := TextColumns[0] := unitsquare xyscaled(w,h+d) shifted (x,y-d) ;
+enddef ;
+
+def ResetLocalTextArea =
+  TextAreas[0] := TextColumns[0] := origin -- cycle ;
+enddef ;
+
+ResetLocalTextArea ;
+
+vardef InsideTextArea (expr _i_, _xy_) =
+  ( (round(xpart _xy_) >= round(xpart llcorner TextAreas[_i_])) and
+    (round(xpart _xy_) <= round(xpart lrcorner TextAreas[_i_])) and
+    (round(ypart _xy_) >= round(ypart llcorner TextAreas[_i_])) and
+    (round(ypart _xy_) <= round(ypart urcorner TextAreas[_i_])) )
+enddef ;
+
+vardef InsideSavedTextArea (expr _i_, _xy_) =
+  ( (round(xpart _xy_) >= round(xpart llcorner SavedTextAreas[_i_])) and
+    (round(xpart _xy_) <= round(xpart lrcorner SavedTextAreas[_i_])) and
+    (round(ypart _xy_) >= round(ypart llcorner SavedTextAreas[_i_])) and
+    (round(ypart _xy_) <= round(ypart urcorner SavedTextAreas[_i_])) )
+enddef ;
+
+vardef InsideSomeTextArea(expr _xy_) =
+  save ok ; boolean ok ; ok := false ;
+  for i := 1 upto NOfTextAreas :
+    if InsideTextArea(i,_xy_) : ok := true ; fi ;
+    exitif ok ;
+  endfor ;
+  ok
+enddef ;
+
+vardef InsideSomeSavedTextArea(expr _xy_) =
+  save ok ; boolean ok ; ok := false ;
+  for i := 1 upto NOfSavedTextAreas :
+    if InsideSavedTextArea(i,_xy_) : ok := true ; fi ;
+    exitif ok ;
+  endfor ;
+  ok
+enddef ;
+
+vardef TextAreaX (expr x) =
+  numeric _TextAreaX_ ; _TextAreaX_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) :
+      _TextAreaX_ := xpart llcorner TextAreas[i] ;
+    fi ;
+  endfor ;
+  _TextAreaX_
+enddef ;
+
+vardef TextAreaY (expr y) =
+  numeric _TextAreaY_ ; _TextAreaY_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(y) >= round(ypart llcorner TextAreas[NOfTextAreas])) and
+       (round(y) <= round(ypart ulcorner TextAreas[NOfTextAreas])) :
+      _TextAreaY_ := ypart llcorner TextAreas[NOfTextAreas] ;
+    fi ;
+  endfor ;
+  _TextAreaY_
+enddef ;
+
+vardef TextAreaXY (expr x, y) =
+  pair _TextAreaXY_ ; _TextAreaXY_ := origin ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) and
+       (round(y) >= round(ypart llcorner TextAreas[i])) and
+       (round(y) <= round(ypart ulcorner TextAreas[i])) :
+      _TextAreaXY_ := llconer TextAreas[i] ;
+    fi ;
+  endfor ;
+  _TextAreaXY_
+enddef ;
+
+vardef TextAreaW (expr x) =
+  numeric _TextAreaW_ ; _TextAreaW_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) :
+      _TextAreaW_ := bbwidth(TextAreas[i]) ;
+    fi ;
+  endfor ;
+  _TextAreaW_
+enddef ;
+
+vardef TextAreaH (expr y) =
+  numeric _TextAreaH_ ; _TextAreaH_ := 0 ;
+  for i := 1 upto NOfTextAreas :
+    if (round(y) >= round(ypart llcorner TextAreas[i])) and
+       (round(y) <= round(ypart ulcorner TextAreas[i])) :
+      _TextAreaH_ := bbheight(TextAreas[i]) ;
+    fi ;
+  endfor ;
+  _TextAreaH_
+enddef ;
+
+vardef TextAreaWH (expr x, y) =
+  pair _TextAreaWH_ ; _TextAreaWH_ := origin ;
+  for i := 1 upto NOfTextAreas :
+    if (round(x) >= round(xpart llcorner TextAreas[i])) and
+       (round(x) <= round(xpart lrcorner TextAreas[i])) and
+       (round(y) >= round(ypart llcorner TextAreas[i])) and
+       (round(y) <= round(ypart ulcorner TextAreas[i])) :
+      _TextAreaWH_ := (bbwidth(TextAreas[i]),bbheight(TextAreas[i])) ;
+    fi ;
+  endfor ;
+  _TextAreaWH_
+enddef ;
+
+PageNumber          := 0 ;
+PaperHeight         := 845.04684pt  ;
+PaperWidth          := 597.50787pt  ;
+PrintPaperHeight    := 845.04684pt  ;
+PrintPaperWidth     := 597.50787pt  ;
+TopSpace            :=  71.12546pt  ;
+BottomSpace         :=   0.0pt      ;
+BackSpace           :=  71.13275pt  ;
+CutSpace            :=   0.0pt      ;
+MakeupHeight        := 711.3191pt   ;
+MakeupWidth         := 426.78743pt  ;
+TopHeight           :=   0.0pt      ;
+TopDistance         :=   0.0pt      ;
+HeaderHeight        :=  56.90294pt  ;
+HeaderDistance      :=   0.0pt      ;
+TextHeight          := 597.51323pt  ;
+FooterDistance      :=   0.0pt      ;
+FooterHeight        :=  56.90294pt  ;
+BottomDistance      :=   0.0pt      ;
+BottomHeight        :=   0.0pt      ;
+LeftEdgeWidth       :=   0.0pt      ;
+LeftEdgeDistance    :=   0.0pt      ;
+LeftMarginWidth     :=   75.58197pt ;
+LeftMarginDistance  :=   11.99829pt ;
+TextWidth           :=  426.78743pt ;
+RightMarginDistance :=   11.99829pt ;
+RightMarginWidth    :=   75.58197pt ;
+RightEdgeDistance   :=    0.0pt     ;
+RightEdgeWidth      :=    0.0pt     ;
+
+PageOffset          :=    0.0pt     ;
+PageDepth           :=    0.0pt     ;
+
+LayoutColumns       :=    0         ;
+LayoutColumnDistance:=    0.0pt     ;
+LayoutColumnWidth   :=    0.0pt     ;
+
+LeftEdge             :=  -4 ; Top             := -40 ;
+LeftEdgeSeparator    :=  -3 ; TopSeparator    := -30 ;
+LeftMargin           :=  -2 ; Header          := -20 ;
+LeftMarginSeparator  :=  -1 ; HeaderSeparator := -10 ;
+Text                 :=   0 ; Text            :=   0 ;
+RightMarginSeparator :=  +1 ; FooterSeparator := +10 ;
+RightMargin          :=  +2 ; Footer          := +20 ;
+RightEdgeSeparator   :=  +3 ; BottomSeparator := +30 ;
+RightEdge            :=  +4 ; Bottom          := +40 ;
+
+Margin      := LeftMargin  ; % obsolete
+Edge        := LeftEdge    ; % obsolete
+InnerMargin := RightMargin ; % obsolete
+InnerEdge   := RightEdge   ; % obsolete
+OuterMargin := LeftMargin  ; % obsolete
+OuterEdge   := LeftEdge    ; % obsolete
+
+InnerMarginWidth     := 0pt ;
+OuterMarginWidth     := 0pt ;
+InnerMarginDistance  := 0pt ;
+OuterMarginDistance  := 0pt ;
+
+InnerEdgeWidth     := 0pt ;
+OuterEdgeWidth     := 0pt ;
+InnerEdgeDistance  := 0pt ;
+OuterEdgeDistance  := 0pt ;
+
+path Area [][] ; pair Location [][] ; path Field [][] ;  path Page ;
+numeric HorPos ; numeric Hstep [] ; numeric Hsize [] ;
+numeric VerPos ; numeric Vstep [] ; numeric Vsize [] ;
+
+for VerPos=Top step 10 until Bottom:
+  for HorPos=LeftEdge step 1 until RightEdge:
+    Area[HorPos][VerPos] := origin--cycle ;
+    Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
+    Location[HorPos][VerPos] := origin ;
+    Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
+    Field[HorPos][VerPos] := origin--cycle ;
+    Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
+  endfor ;
+endfor ;
+
+% def LoadPageState =
+%   scantokens "input mp-state.tmp" ;
+% enddef ;
+
+def SwapPageState =
+  if not OnRightPage :
+           BackSpace := PaperWidth-MakeupWidth-BackSpace ;
+            CutSpace := PaperWidth-MakeupWidth-CutSpace ;
+                   i := LeftMarginWidth ;
+     LeftMarginWidth := RightMarginWidth ;
+    RightMarginWidth := i ;
+                   i := LeftMarginDistance ;
+  LeftMarginDistance := RightMarginDistance ;
+ RightMarginDistance := i ;
+                   i := LeftEdgeWidth ;
+       LeftEdgeWidth := RightEdgeWidth ;
+      RightEdgeWidth := i ;
+                   i := LeftEdgeDistance ;
+    LeftEdgeDistance := RightEdgeDistance ;
+   RightEdgeDistance := i ;
+
+% these are now available as ..Width and ..Distance
+
+              Margin := LeftMargin ;
+                Edge := LeftEdge ;
+         InnerMargin := RightMargin ;
+           InnerEdge := RightEdge ;
+         OuterMargin := LeftMargin ;
+           OuterEdge := LeftEdge ;
+  else :
+              Margin := RightMargin ;
+                Edge := RightEdge ;
+         InnerMargin := LeftMargin ;
+           InnerEdge := LeftEdge ;
+         OuterMargin := RightMargin ;
+           OuterEdge := RightEdge ;
+  fi ;
+enddef ;
+
+def SetPageAreas =
+
+  numeric Vsize[], Hsize[], Vstep[], Hstep[] ;
+
+  Vsize[Top]             = TopHeight ;
+  Vsize[TopSeparator]    = TopDistance ;
+  Vsize[Header]          = HeaderHeight ;
+  Vsize[HeaderSeparator] = HeaderDistance ;
+  Vsize[Text]            = TextHeight ;
+  Vsize[FooterSeparator] = FooterDistance ;
+  Vsize[Footer]          = FooterHeight ;
+  Vsize[BottomSeparator] = BottomDistance ;
+  Vsize[Bottom]          = BottomHeight ;
+
+  Vstep[Top]             = Vstep[TopSeparator]   +Vsize[TopSeparator] ;
+  Vstep[TopSeparator]    = PaperHeight-TopSpace ;
+  Vstep[Header]          = Vstep[TopSeparator]   -Vsize[Header] ;
+  Vstep[HeaderSeparator] = Vstep[Header]         -Vsize[HeaderSeparator] ;
+  Vstep[Text]            = Vstep[HeaderSeparator]-Vsize[Text] ;
+  Vstep[FooterSeparator] = Vstep[Text]           -Vsize[FooterSeparator] ;
+  Vstep[Footer]          = Vstep[FooterSeparator]-Vsize[Footer] ;
+  Vstep[BottomSeparator] = Vstep[Footer]         -Vsize[BottomSeparator] ;
+  Vstep[Bottom]          = Vstep[BottomSeparator]-Vsize[Bottom] ;
+
+  Hsize[LeftEdge]             = LeftEdgeWidth ;
+  Hsize[LeftEdgeSeparator]    = LeftEdgeDistance ;
+  Hsize[LeftMargin]           = LeftMarginWidth ;
+  Hsize[LeftMarginSeparator]  = LeftMarginDistance ;
+  Hsize[Text]                 = MakeupWidth ;
+  Hsize[RightMarginSeparator] = RightMarginDistance ;
+  Hsize[RightMargin]          = RightMarginWidth ;
+  Hsize[RightEdgeSeparator]   = RightEdgeDistance ;
+  Hsize[RightEdge]            = RightEdgeWidth ;
+
+  Hstep[LeftEdge]             = Hstep[LeftEdgeSeparator]   -Hsize[LeftEdge] ;
+  Hstep[LeftEdgeSeparator]    = Hstep[LeftMargin]          -Hsize[LeftEdgeSeparator] ;
+  Hstep[LeftMargin]           = Hstep[LeftMarginSeparator] -Hsize[LeftMargin] ;
+  Hstep[LeftMarginSeparator]  = Hstep[Text]                -Hsize[LeftMarginSeparator] ;
+  Hstep[Text]                 = BackSpace ;
+  Hstep[RightMarginSeparator] = Hstep[Text]                +Hsize[Text] ;
+  Hstep[RightMargin]          = Hstep[RightMarginSeparator]+Hsize[RightMarginSeparator] ;
+  Hstep[RightEdgeSeparator]   = Hstep[RightMargin]         +Hsize[RightMargin] ;
+  Hstep[RightEdge]            = Hstep[RightEdgeSeparator]  +Hsize[RightEdgeSeparator] ;
+
+  for VerPos=Top step 10 until Bottom:
+    for HorPos=LeftEdge step 1 until RightEdge:
+      Area[HorPos][VerPos] := unitsquare xscaled Hsize[HorPos] yscaled Vsize[VerPos] ;
+      Area[VerPos][HorPos] := Area[HorPos][VerPos] ;
+      Location[HorPos][VerPos] := (Hstep[HorPos],Vstep[VerPos]) ;
+      Location[VerPos][HorPos] := Location[HorPos][VerPos] ;
+      Field[HorPos][VerPos] := Area[HorPos][VerPos] shifted Location[HorPos][VerPos] ;
+      Field[VerPos][HorPos] := Field[HorPos][VerPos] ;
+    endfor ;
+  endfor ;
+
+  Page := unitsquare xscaled PaperWidth yscaled PaperHeight ;
+
+enddef ;
+
+def BoundPageAreas =
+
+ % pickup pencircle scaled 0pt ;
+
+  bboxmargin := 0 ; setbounds currentpicture to Page ;
+
+enddef ;
+
+def StartPage =
+
+  if PageStateAvailable :
+    LoadPageState ;
+    SwapPageState ;
+  fi ;
+
+  SetPageAreas ;
+  BoundPageAreas ;
+
+enddef ;
+
+def StopPage =
+
+  BoundPageAreas ;
+
+enddef ;
+
+def OverlayBox =
+  (unitsquare xyscaled (OverlayWidth,OverlayHeight))
+enddef ;
+
+% handy
+
+def innerenlarged =
+  hide(LoadPageState)
+  if OnRightPage : leftenlarged  else : rightenlarged fi
+enddef ;
+
+def outerenlarged =
+  hide(LoadPageState)
+  if OnRightPage : rightenlarged else : leftenlarged  fi
+enddef ;
+
+% obsolete
+
+def llEnlarged (expr p,d) = (llcorner p shifted (-d,-d)) enddef ;
+def lrEnlarged (expr p,d) = (lrcorner p shifted (+d,-d)) enddef ;
+def urEnlarged (expr p,d) = (urcorner p shifted (+d,+d)) enddef ;
+def ulEnlarged (expr p,d) = (ulcorner p shifted (-d,+d)) enddef ;
+
+def Enlarged (expr p, d) =
+  (llEnlarged (p,d) --
+   lrEnlarged (p,d) --
+   urEnlarged (p,d) --
+   ulEnlarged (p,d) -- cycle)
+enddef ;
+
+endinput ;
\ No newline at end of file
diff --git a/Master/texmf-dist/metapost/context/base/mp-shap.mp b/Master/texmf-dist/metapost/context/base/mp-shap.mp
new file mode 100644
index 00000000000..0f5fe431d99
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-shap.mp
@@ -0,0 +1,307 @@
+%D \module
+%D   [       file=mp-shap.mp,
+%D        version=2000.05.31, 
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=shapes,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for 
+%C details. 
+
+if unknown context_tool :    input mp-tool ; fi ; 
+if   known context_shap : endinput         ; fi ; 
+
+boolean context_shap ; context_shap := true ; 
+
+vardef some_shape_path (expr type) =
+
+    begingroup ;
+
+    save border, xradius, yradius, 
+         normal, mirror, rotate, 
+         lc, rc, tc, bc, ll, lr, ur, ul, 
+         llx, lrx, urx, ulx, lly, lry, ury, uly ;
+
+    path border ;
+
+    xradius := .15 ; xxradius := .10 ; 
+    yradius := .15 ; yyradius := .10 ; 
+
+    pair ll ; ll := llcorner (unitsquare shifted (-.5,-.5)) ;
+    pair lr ; lr := lrcorner (unitsquare shifted (-.5,-.5)) ;
+    pair ur ; ur := urcorner (unitsquare shifted (-.5,-.5)) ;
+    pair ul ; ul := ulcorner (unitsquare shifted (-.5,-.5)) ;
+
+    pair llx ; llx := ll shifted (xradius,0)  ;
+    pair lly ; lly := ll shifted (0,yradius)  ;
+
+    pair lrx ; lrx := lr shifted (-xradius,0) ;
+    pair lry ; lry := lr shifted (0,yradius)  ;
+
+    pair urx ; urx := ur shifted (-xradius,0) ;
+    pair ury ; ury := ur shifted (0,-yradius) ;
+
+    pair ulx ; ulx := ul shifted (xradius,0)  ;
+    pair uly ; uly := ul shifted (0,-yradius) ;
+
+    pair llxx ; llxx := ll shifted (xxradius,0)  ;
+    pair llyy ; llyy := ll shifted (0,yyradius)  ;
+
+    pair lrxx ; lrxx := lr shifted (-xxradius,0) ;
+    pair lryy ; lryy := lr shifted (0,yyradius)  ;
+
+    pair urxx ; urxx := ur shifted (-xxradius,0) ;
+    pair uryy ; uryy := ur shifted (0,-yyradius) ;
+
+    pair ulxx ; ulxx := ul shifted (xxradius,0)  ;
+    pair ulyy ; ulyy := ul shifted (0,-yyradius) ;
+
+    pair lc  ; lc  := ll shifted (0,.5) ;
+    pair rc  ; rc  := lr shifted (0,.5) ;
+    pair tc  ; tc  := ul shifted (.5,0) ;
+    pair bc  ; bc  := ll shifted (.5,0) ;
+
+    def mirror (expr p) =
+      p rotatedaround(origin,180)
+    enddef ;
+
+    def normal (expr p ) =
+      p
+    enddef ;
+
+    def rotate (expr p) = 
+      p rotated 45 
+    enddef ; 
+
+    if     type= 0 :
+      border := normal (origin--cycle) ;
+
+    elseif type= 5 :
+      border := normal (llx--lrx{right}...rc...{left}urx--ulx{left}...lc...{right}cycle) ;
+    elseif type= 6 :
+      border := normal (ll--lrx{right}...rc...{left}urx--ul--cycle) ;
+    elseif type= 7 :
+      border := mirror (ll--lrx{right}...rc...{left}urx--ul--cycle) ;
+    elseif type= 8 :
+      border := normal (lr--ury{up}...tc...{down}uly--ll--cycle) ;
+    elseif type= 9 :
+      border := mirror (lr--ury{up}...tc...{down}uly--ll--cycle) ;
+    elseif type=10 :
+      border := normal (ll--lr--ur--ul--ll--ur--ul--ll--cycle) ; 
+    elseif type=11 :
+      border := normal (ll--lr--ur--ul--ll--lr--ul--ll--cycle) ; 
+    elseif type=12 :
+      border := normal (ll--lrx--ur--ulx--cycle) ;
+    elseif type=13 :
+      border := normal (llx--lr--urx--ul--cycle) ;
+    elseif type=14 :
+      border := normal (lly--bc--lry--ury--tc--uly--cycle) ;
+    elseif type=15 :
+      border := normal (llx--lrx--rc--urx--ulx--lc--cycle) ;
+    elseif type=16 :
+      border := normal (ll--lrx--rc--urx--ul--cycle) ;
+    elseif type=17 :
+      border := mirror (ll--lrx--rc--urx--ul--cycle) ;
+    elseif type=18 :
+      border := normal (lr--ury--tc--uly--ll--cycle) ;
+    elseif type=19 :
+      border := mirror (lr--ury--tc--uly--ll--cycle) ;
+    elseif type=20 :
+      border := normal (ll--lr--ur--ul--ll--llxx--ulxx--ul--ll--
+                        lr--ur--urxx--lrxx--cycle) ;
+    elseif type=21 :
+      border := normal (ul--ll--lr--ur--ul--ulyy--uryy--ur--ul--
+                        ll--lr--lryy--llyy--cycle) ;
+    elseif type=22 :
+      border := normal (ll--lrx--lry--ur--ulx--uly--cycle) ;
+    elseif type=23 :
+      border := normal (llx--lr--ury--urx--ul--lly--cycle) ;
+    elseif type=24 :
+      border := normal (ll--lr--ur--ul--cycle) ;
+    elseif type=25 :
+      border := normal (llx--lrx--lry--ury--urx--ulx--uly--lly--cycle) ;
+    elseif type=26 :
+      border := normal (ll--lrx--lry--ur--ul--cycle) ;
+    elseif type=27 :
+      border := mirror (ll--lr--ury--urx--ul--cycle) ;
+    elseif type=28 :
+      border := normal (ll--lr--ury--urx--ul--cycle) ;
+    elseif type=29 :
+      border := mirror (ll--lrx--lry--ur--ul--cycle) ;
+    elseif type=30 :
+      border := rotate (bc{right}...{up}rc...tc{left}...{down}lc...{right}bc &
+                        bc--tc & tc{left}..{down}lc & lc--rc & 
+                        rc{up}..tc{left}...{down}lc...{right}bc & cycle) ;
+    elseif type=31 :
+      border := normal (bc{right}...{up}rc...tc{left}...{down}lc...{right}bc &
+                        bc--tc & tc{left}..{down}lc & lc--rc & 
+                        rc{up}..tc{left}...{down}lc...{right}bc & cycle) ;
+    elseif type=32 :
+      border := normal (ll{right}...{right}lry--ur--ul--ll--cycle) ;
+    elseif type=33 :
+      border := normal (ll{right}...{right}lry--ur--ul--ll--cycle
+                        --ul--ulx--ulx shifted(0,yyradius)
+                        --ur shifted(yyradius,yyradius)
+                        --lry shifted(yyradius,yyradius)
+                        --lry shifted(0,yyradius)
+                        --ur--ul--cycle ) ;
+    elseif type=34 :
+      border := normal (uly..tc..ury & 
+                        ury..tc shifted (0,-2yradius)..uly & 
+                        uly--lly &
+                        lly..bc..lry &
+                        lry--ury & 
+                        ury..tc shifted (0,-2yradius)..uly & cycle ) ;  
+    elseif type=35 :
+      border := normal (bc{right}...rc{up}...tc{left}...lc{down}...cycle) ;
+    elseif type=36 :
+      border := normal (ul--tc{right}..rc{down}..{left}bc--ll & 
+                        ll..(xpart llx, ypart lc)..ul & cycle) ;
+    elseif type=37 :
+      border := mirror (ul--tc{right}..rc{down}..{left}bc--ll & 
+                        ll..(xpart llx, ypart lc)..ul & cycle) ;
+    elseif type=38 :
+      border := normal (ll--lc{up}..tc{right}..{down}rc--lr & 
+                        lr..(xpart bc, ypart lly)..ll & cycle) ;
+    elseif type=39 :
+      border := mirror (ll--lc{up}..tc{right}..{down}rc--lr & 
+                        lr..(xpart bc, ypart lly)..ll & cycle) ;
+    elseif type=40 :
+      border := normal (ll--lr--ur--ul--ll--ur--ul--ll--lr--ul--ll--cycle) ; 
+    elseif type=41 :
+      border := normal (ll--lr--ur--ul--ll--lr--rc--lc--ll--bc--tc--ul--ll & cycle) ; 
+    elseif type=42 :
+      border := normal (ll--lr--origin shifted (+epsilon,0)--
+                        ur--ul--origin shifted (-epsilon,0)--cycle) ; 
+    elseif type=43 :
+      border := normal (ll--ul--origin shifted (0,+epsilon)--
+                        ur--lr--origin shifted (0,-epsilon)--cycle) ; 
+    elseif type=45 :
+      border := normal (bc--rc--tc--lc--cycle) ;
+    elseif type=46 :
+      border := normal (ll--ul--rc--cycle) ;
+    elseif type=47 :
+      border := mirror (ll--ul--rc--cycle) ;
+    elseif type=48 :
+      border := mirror (ul--ur--bc--cycle) ;
+    elseif type=49 :
+      border := normal (ul--ur--bc--cycle) ;
+
+    elseif type=56 :
+      border := normal (ll--lry--ury--ul--cycle) ;
+    elseif type=57 :
+      border := mirror (ll--lry--ury--ul--cycle) ;
+    elseif type=58 :
+      border := normal (ll--ulx--urx--lr--cycle) ;
+    elseif type=59 :
+      border := mirror (ll--ulx--urx--lr--cycle) ;
+
+    elseif type=61 : 
+      border := normal (fullcircle scaled (1.5*yradius) xscaled (grid_height/grid_width)) ;
+    elseif type=62 : 
+      border := normal (fullcircle scaled (2.0*yradius) xscaled (grid_height/grid_width)) ;
+
+    elseif type=66 :
+      border := normal (rc--origin shifted ( epsilon,0) --cycle & 
+                        rc--origin                      --cycle ) ;
+    elseif type=67 :
+      border := normal (lc--origin shifted (-epsilon,0) --cycle & 
+                        lc--origin                      --cycle ) ;
+    elseif type=68 :
+      border := normal (tc--origin shifted (0, epsilon) --cycle & 
+                        tc--origin                      --cycle ) ;
+    elseif type=69 :
+      border := normal (bc--origin shifted (0,-epsilon) --cycle & 
+                        bc--origin                      --cycle ) ;
+
+    elseif type=75 : 
+      border := mirror (lly--lry--ury--uly--cycle) ;
+    elseif type=76 : 
+      border := mirror (ll--lr--ur--uly--cycle) ;
+    elseif type=77 : 
+      border := mirror (ll--lr--ury--ul--cycle) ;
+    elseif type=78 : 
+      border := mirror (lly--lr--ur--ul--cycle) ;
+    elseif type=79 : 
+      border := mirror (ll--lry--ur--ul--cycle) ;
+
+    else :
+      border := normal (origin--cycle) ;
+     %border := normal (ll--lr--ur--ul--cycle) ;
+    fi ;
+
+    border
+
+    endgroup
+
+enddef;
+
+def some_shape ( expr shape_type      , 
+                      shape_width     , 
+                      shape_height    , 
+                      shape_linewidth , 
+                      shape_linecolor ,     
+                      shape_fillcolor ) = 
+
+  path p ; p := 
+    some_shape_path (shape_type) 
+      xscaled shape_width 
+      yscaled shape_height ; 
+
+  pickup pencircle scaled shape_linewidth ;
+
+  fill p withcolor shape_fillcolor ; 
+  draw p withcolor shape_linecolor ; 
+ 
+enddef ; 
+
+vardef drawshape (expr t, p, lw, lc, fc) =
+  save pp ; 
+  if t>1 : % normal shape
+    path pp ;
+    pp := some_shape_path(t) xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
+    fill pp withcolor fc ;
+    draw pp withpen pencircle scaled lw withcolor lc ;
+  elseif t=1 : % background only 
+    path pp ; 
+    pp := fullsquare xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
+    fill pp withcolor fc ;
+  else : % dimensions only 
+    picture pp ; pp := nullpicture ; 
+    setbounds pp to fullsquare xyscaled(bbwidth(p), bbheight(p)) shifted center p ;
+    draw pp ; 
+  fi ; 
+enddef ;
+
+vardef drawline (expr t, p, lw, lc) =
+  if (t>0) and (length(p)>1) :
+    saveoptions ;
+    drawoptions(withpen pencircle scaled lw withcolor lc) ;
+    draw p ;
+    if     t =  1 : 
+      draw arrowheadonpath(p,1) ;
+    elseif t =  2 :
+      draw arrowheadonpath(reverse p,1) ;
+    elseif t =  3 :
+      for $ = p,reverse p : draw arrowheadonpath($,1) ; endfor ; 
+    elseif t = 11 :
+      draw arrowheadonpath(p,1/2) ;
+    elseif t = 12 :
+      draw arrowheadonpath(reverse p,1/2) ;
+    elseif t = 13 :
+      for $=p,reverse p : draw arrowheadonpath($,1) ; endfor ;
+      for $=p,reverse p : draw arrowheadonpath($,3/4) ; endfor ;
+    elseif t = 21 :
+      for $=1/5,1/2,4/5 : draw arrowheadonpath(p,$) ; endfor ;
+    elseif t = 22 :
+      for $=1/5,1/2,4/5 : draw arrowheadonpath(reverse p,$) ; endfor ;
+    elseif t = 23 :
+      for $=p,reverse p : draw arrowheadonpath($,1/4) ; endfor ;
+    fi ;
+  fi ; 
+enddef ;
+
+endinput ;  
diff --git a/Master/texmf-dist/metapost/context/base/mp-spec.mp b/Master/texmf-dist/metapost/context/base/mp-spec.mp
new file mode 100644
index 00000000000..9fe3c724fdc
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-spec.mp
@@ -0,0 +1,775 @@
+%D \module
+%D   [       file=mp-spec.mp,
+%D        version=1999.6.26,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=special extensions,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+% Spot colors are not handled by mptopdf !
+
+% (r,g,b) => cmyk             : r=123 g=   1 b=hash
+%         => spot             : r=123 g=   2 b=hash
+%         => transparent rgb  : r=123 g=   3 b=hash
+%         => transparent cmyk : r=123 g=   4 b=hash
+%         => transparent spot : r=123 g=   5 b=hash
+%         => rest             : r=123 g=n>10 b=whatever
+
+%D This module is rather preliminary and subjected to
+%D changes. Here we closely cooperates with the \METAPOST\
+%D to \PDF\ converter module built in \CONTEXT\ and provides
+%D for instance shading. More information can be found in
+%D type {supp-mpe.tex}.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_spec : endinput         ; fi ;
+
+boolean context_spec ; context_spec := true ;
+
+numeric _special_counter_ ; _special_counter_ :=   0 ;
+numeric _color_counter_   ; _color_counter_   :=  11 ; % < 10 reserved
+numeric _special_signal_  ; _special_signal_  := 123 ;
+
+%D When set to \type {true}, shading will be supported. Some
+%D day I will also write an additional directive.
+
+boolean _inline_specials_ ; _inline_specials_ := false ;
+
+%D Because we want to output only those specials that are
+%D actually used in a figure, we need a bit complicated
+%D bookkeeping and collection of specials. At the cost of some
+%D obscurity, we now have rather efficient resources.
+
+string _global_specials_ ; _global_specials_ := "" ;
+string _local_specials_  ; _local_specials_  := "" ;
+
+vardef add_special_signal = % write the version number
+  if (length _global_specials_>0) or (length _local_specials_ >0) :
+    special ("%%MetaPostSpecials: 1.0 " & decimal _special_signal_ ) ;
+  fi ;
+enddef ;
+
+vardef add_extra_specials =
+  scantokens _global_specials_ ;
+  scantokens _local_specials_ ;
+enddef ;
+
+vardef reset_extra_specials =
+  % only local ones
+  _local_specials_ := "" ;
+enddef ;
+
+boolean insidefigure ; insidefigure := false ;
+
+% todo: alleen als special gebruikt flush
+
+extra_beginfig :=
+  " insidefigure := true ; " &
+  " reset_extra_specials ; " &
+    extra_beginfig ;
+
+extra_endfig :=
+  " add_special_signal ; "    &
+    extra_endfig              &
+  " add_extra_specials ; "    &
+  " reset_extra_specials ; "  &
+  " insidefigure := false ; " ;
+
+def set_extra_special (expr s) =
+  if insidefigure :
+    _local_specials_  := _local_specials_  & s ;
+  else :
+    _global_specials_ := _global_specials_ & s ;
+  fi
+enddef ;
+
+def flush_special (expr typ, siz, dat) =
+  _special_counter_ := _special_counter_ + 1 ;
+  if _inline_specials_ :
+    set_extra_special
+      ( "special "
+      & "(" & ditto
+      & dat & " "
+      & decimal _special_counter_ & " "
+      & decimal typ & " "
+      & decimal siz
+      & " special"
+      & ditto & ");" ) ;
+  else :
+    set_extra_special
+      ( "special "
+      & "(" & ditto
+      & "%%MetaPostSpecial: "
+      & decimal siz & " "
+      & dat & " "
+      & decimal _special_counter_ & " "
+      & decimal typ
+      & ditto & ");" ) ;
+  fi ;
+enddef ;
+
+%D The next hack is needed in case you use a version of
+%D \METAPOST\ that does not provide you the means to configure
+%D the buffer size. Patrick Gundlach suggested to use arrays
+%D in this case.
+
+boolean bufferhack ; bufferhack := false ; % true ;
+
+if bufferhack :
+
+  string _global_specials_[] ; numeric _nof_global_specials_ ;
+  string _local_specials_[]  ; numeric _nof_local_specials_ ;
+
+  _nof_global_specials_ := _nof_local_specials_ := 0 ;
+
+  vardef add_special_signal = % write the version number
+    if (_nof_global_specials_>0) or (_nof_local_specials_>0) :
+      special ("%%MetaPostSpecials: 1.0 " & decimal _special_signal_ ) ;
+    fi ;
+  enddef ;
+
+  vardef add_extra_specials =
+    for i=1 upto _nof_global_specials_ :
+      scantokens _global_specials_[i] ;
+    endfor;
+    for i=1 upto _nof_local_specials_ :
+      scantokens _local_specials_[i] ;
+    endfor;
+  enddef ;
+
+  vardef reset_extra_specials =
+    string _local_specials_[]  ; _nof_local_specials_ := 0 ;
+  enddef ;
+
+  def set_extra_special (expr s) =
+    if insidefigure :
+      _local_specials_[incr(_nof_local_specials_)]   := s ;
+    else :
+      _global_specials_[incr(_nof_global_specials_)] := s ;
+    fi
+  enddef ;
+
+fi ;
+
+%D So far for this hack.
+
+%D Shade allocation.
+
+newinternal shadefactor ; shadefactor := 1 ;
+
+pair shadeoffset ; shadeoffset := origin ;
+
+vardef define_linear_shade (expr a, b, ca, cb) =
+  flush_special(30, 15, "0 1 " & decimal shadefactor & " " &
+    dddecimal ca & " " & ddecimal (a shifted shadeoffset) & " " &
+    dddecimal cb & " " & ddecimal (b shifted shadeoffset) ) ;
+  _special_counter_
+enddef ;
+
+vardef define_circular_shade (expr a, b, ra, rb, ca, cb) =
+  flush_special(31, 17, "0 1 " & decimal shadefactor & " " &
+    dddecimal ca & " " & ddecimal (a shifted shadeoffset) & " " & decimal ra & " " &
+    dddecimal cb & " " & ddecimal (b shifted shadeoffset) & " " & decimal rb ) ;
+  _special_counter_
+enddef ;
+
+%D A few predefined shading macros.
+
+boolean trace_shades ; trace_shades := false ;
+
+%  if     (n=1) : a := llcorner p ; b := urcorner p ;
+%  elseif (n=2) : a := llcorner p ; b := ulcorner p ;
+%  elseif (n=3) : a := lrcorner p ; b := ulcorner p ;
+%  else         : a := llcorner p ; b := lrcorner p ;
+%  fi ;
+
+def set_linear_vector (suffix a,b)(expr p,n) =
+  if     (n=1) : a := llcorner p ;
+                 b := urcorner p ;
+  elseif (n=2) : a := lrcorner p ;
+                 b := ulcorner p ;
+  elseif (n=3) : a := urcorner p ;
+                 b := llcorner p ;
+  elseif (n=4) : a := ulcorner p ;
+                 b := lrcorner p ;
+  elseif (n=5) : a := .5[ulcorner p,llcorner p] ;
+                 b := .5[urcorner p,lrcorner p] ;
+  elseif (n=6) : a := .5[llcorner p,lrcorner p] ;
+                 b := .5[ulcorner p,urcorner p] ;
+  elseif (n=7) : a := .5[lrcorner p,urcorner p] ;
+                 b := .5[llcorner p,ulcorner p] ;
+  elseif (n=8) : a := .5[urcorner p,ulcorner p] ;
+                 b := .5[lrcorner p,llcorner p] ;
+  else         : a := .5[ulcorner p,llcorner p] ;
+                 b := .5[urcorner p,lrcorner p] ;
+  fi ;
+enddef ;
+
+def linear_shade (expr p, n, ca, cb) =
+  begingroup ;
+  save a, b, sh ; pair a, b ;
+  set_linear_vector(a,b)(p,n) ;
+  fill p withshade define_linear_shade (a,b,ca,cb) ;
+  if trace_shades :
+    drawarrow a -- b withpen pencircle scaled 1pt ;
+  fi ;
+  endgroup ;
+enddef ;
+
+vardef predefined_linear_shade (expr p, n, ca, cb) =
+  save a, b, sh ; pair a, b ;
+  set_linear_vector(a,b)(p,n) ;
+  set_shade_vector(a,b)(p,n) ;
+  define_linear_shade (a,b,ca,cb)
+enddef ;
+
+def set_circular_vector (suffix ab, r)(expr p,n) =
+  if     (n=1) : ab := llcorner p ;
+  elseif (n=2) : ab := lrcorner p ;
+  elseif (n=3) : ab := urcorner p ;
+  elseif (n=4) : ab := ulcorner p ;
+  else         : ab := center   p ; r := .5r ;
+  fi ;
+enddef ;
+
+def circular_shade (expr p, n, ca, cb) =
+  begingroup ;
+  save ab, r ; pair ab ; numeric r ;
+  r := (xpart lrcorner p - xpart llcorner p) ++
+       (ypart urcorner p - ypart lrcorner p) ;
+  set_circular_vector(ab,r)(p,n) ;
+  fill p withshade define_circular_shade(ab,ab,0,r,ca,cb) ;
+  if trace_shades :
+    drawarrow ab -- ab shifted (0,r) withpen pencircle scaled 1pt ;
+  fi ;
+  endgroup ;
+enddef ;
+
+vardef predefined_circular_shade (expr p, n, ca, cb) =
+  save ab, r ; pair ab ; numeric r ;
+  r := (xpart lrcorner p - xpart llcorner p) ++
+       (ypart urcorner p - ypart lrcorner p) ;
+  set_circular_vector(ab,r)(p,n) ;
+  define_circular_shade(ab,ab,0,r,ca,cb)
+enddef ;
+
+%D Since a \type {fill p withshade s} syntax looks better
+%D than some macro, we implement a new primary.
+
+primarydef p withshade sc = % == p withcolor shadecolor(sh)
+  hide (_color_counter_ := _color_counter_ + 1)
+  p withcolor (_special_signal_/1000,_color_counter_/1000,sc/1000)
+enddef ;
+
+vardef shadecolor(expr sc) =
+  hide (_color_counter_ := _color_counter_ + 1)
+  (_special_signal_/1000,_color_counter_/1000,sc/1000)
+enddef ;
+
+%D Figure inclusion.
+
+%numeric cef ; cef := 0 ;
+
+def externalfigure primary filename =
+  doexternalfigure (filename)
+enddef ;
+
+def doexternalfigure (expr filename) text transformation =
+  begingroup ; save p, t ; picture p ; transform t ;
+  p := nullpicture ; t := identity transformation ;
+  flush_special(10, 9,
+    dddecimal (xxpart t, yxpart t, xypart t) & " " &
+    dddecimal (yypart t,  xpart t,  ypart t) & " " & filename) ;
+  addto p contour unitsquare scaled 0 ;
+  setbounds p to unitsquare transformed t ;
+  _color_counter_ := _color_counter_ + 1 ;
+  draw p withcolor (_special_signal_/1000,_color_counter_/1000,_special_counter_/1000) ;
+%draw p withcolor (_special_signal_/1000,cef/1000,_special_counter_/1000) ;
+  endgroup ;
+enddef ;
+
+%D Experimental:
+
+%numeric currenthyperlink ; currenthyperlink := 0 ;
+
+def hyperlink primary t = dohyperlink(t) enddef ;
+def hyperpath primary t = dohyperpath(t) enddef ;
+
+def dohyperlink (expr destination) text transformation  =
+  begingroup ; save somepath ; path somepath ;
+  somepath := fullsquare transformation ;
+  dohyperpath(destination) somepath ;
+  endgroup ;
+enddef ;
+
+def dohyperpath (expr destination) expr somepath =
+  begingroup ;
+  flush_special(20, 7,
+    ddecimal (xpart llcorner somepath, ypart llcorner somepath) & " " &
+    ddecimal (xpart urcorner somepath, ypart urcorner somepath) & " " & destination) ;
+%  currenthyperlink := currenthyperlink + 1 ;
+  _color_counter_ := _color_counter_ + 1 ;
+  fill boundingbox unitsquare scaled 0 withcolor
+    (_special_signal_/1000,_color_counter_/1000,_special_counter_/1000) ;
+%    (_special_signal_/1000,currenthyperlink/1000,_special_counter_/1000) ;
+  endgroup ;
+enddef ;
+
+% \setupinteraction[state=start]
+% \setupcolors     [state=start]
+%
+% Hello There! \blank
+%
+% \startMPcode
+% pickup pencircle scaled 5 ;
+% draw fullcircle scaled 4cm withcolor red ;
+% hyperpath "nextpage" boundingbox currentpicture ;
+% draw origin withcolor blue ;
+% \stopMPcode
+%
+% \blank Does it work or not?
+%
+% \startMPcode
+% pickup pencircle scaled 5 ;
+% draw fullcircle scaled 4cm withcolor red ;
+% hyperpath "nextpage" fullcircle scaled 4cm ;
+% draw origin withcolor blue ;
+% draw fullcircle scaled 4cm shifted (1cm,1cm);
+% \stopMPcode
+%
+% \blank Does it work or not? \page Hello There! \blank
+%
+% \startMPcode
+% pickup pencircle scaled 5 ;
+% draw fullcircle scaled 2cm shifted (-2cm,-1cm) ;
+% draw fullcircle scaled 3cm shifted (2cm,1cm) withcolor red ;
+% draw fullcircle scaled 1cm ;
+% hyperlink "previouspage" scaled 3cm shifted (2cm,1cm) ;
+% draw origin withcolor blue ;
+% \stopMPcode
+%
+% \blank Does it work or not?
+
+_cmyk_counter_ := 0 ;
+
+extra_endfig := " resetcmykcolors ; " & extra_endfig ;
+
+def resetcmykcolors =
+  numeric cmykcolorhash[][][][] ;
+enddef ;
+
+resetcmykcolors ; boolean cmykcolors ; cmykcolors := false ; % true
+
+string cmykcolorpattern[] ; % needed for transparancies
+
+vardef cmyk(expr c,m,y,k) =
+  if cmykcolors :
+    save ok ; boolean ok ;
+    if unknown cmykcolorhash[c][m][y][k] :
+      ok := false ; % not yet defined
+    elseif cmykcolorhash[c][m][y][k] = -1 :
+      ok := false ; % locally defined and undefined
+    else :
+      ok := true ;  % globally already defined
+    fi ;
+    if not ok :
+      save s ; string s ; s := dddecimal (c,m,y) & " " & decimal k ;
+      _cmyk_counter_ := _cmyk_counter_ + 1 ;
+      cmykcolorpattern[_cmyk_counter_/1000] := s ;
+      cmykcolorhash[c][m][y][k] := _cmyk_counter_ ;
+      flush_special(1, 7, decimal _cmyk_counter_ & " " & s) ;
+      _local_specials_ := _local_specials_ &
+        " cmykcolorhash[" & decimal c & "][" & decimal m &
+        "][" & decimal y & "][" & decimal k & "] := -1 ; " ;
+    fi ;
+    (_special_signal_/1000,1/1000,cmykcolorhash[c][m][y][k]/1000)
+  else :
+    (1-c-k,1-m-k,1-y-k)
+  fi
+enddef ;
+
+% newcolor truecyan, truemagenta, trueyellow ;
+%
+% truecyan    = cmyk (1,0,0,0) ;
+% truemagenta = cmyk (0,1,0,0) ;
+% trueyellow  = cmyk (0,0,1,0) ;
+
+%D Spot colors
+
+_spotcolor_counter_ := 0 ;
+_spotcolor_number_ := 0 ;
+
+extra_endfig := " resetspotcolors ; " & extra_endfig ;
+
+def resetspotcolors =
+  numeric spotcolorhash[][] ;
+enddef ;
+
+resetspotcolors ; boolean spotcolors ; spotcolors := false ; % true
+
+string spotcolorpattern[] ; % needed for transparancies
+
+% vardef spotcolor(expr p, s) =
+%   if spotcolors :
+%     save ok, pc_tag ; boolean ok ; string pc_tag ;
+%     pc_tag := "_pct_"&p ;
+%     if not unstringed(pc_tag) :
+%       _spotcolor_number_ := _spotcolor_number_ + 1 ;
+%       setunstringed(pc_tag,_spotcolor_number_) ;
+%     fi ;
+%     pp := getunstringed(pc_tag) ;
+%     if unknown spotcolorhash[pp][s] :
+%       ok := false ; % not yet defined
+%     elseif spotcolorhash[pp][s] = -1 :
+%       ok := false ; % locally defined and undefined
+%     else :
+%       ok := true ;  % globally already defined
+%     fi ;
+%     if not ok :
+%       save ss ; string ss ; ss := p & " " & decimal s ;
+%       _spotcolor_counter_ := _spotcolor_counter_ + 1 ;
+%       spotcolorpattern[_spotcolor_counter_/1000] := ss ;
+%       spotcolorhash[pp][s] := _spotcolor_counter_ ;
+%       flush_special(2, 5, decimal _spotcolor_counter_ & " " & ss) ;
+%       _local_specials_ := _local_specials_ &
+%         "spotcolorhash["&decimal pp&"]["&decimal s&"]:=-1;" ;
+%     fi ;
+%     (_special_signal_/1000,2/1000,spotcolorhash[pp][s]/1000)
+%   else :
+%     (1-s,1-s,1-s)
+%   fi
+% enddef ;
+
+% vardef spotcolor(expr p, s) =
+%   if spotcolors :
+%     save ok, pc_tag ; boolean ok ; string pc_tag ;
+%     pc_tag := "_pct_"&p ;
+%     if not unstringed(pc_tag) :
+%       _spotcolor_number_ := _spotcolor_number_ + 1 ;
+%       setunstringed(pc_tag,_spotcolor_number_) ;
+%     fi ;
+%     pp := getunstringed(pc_tag) ;
+%     if unknown spotcolorhash[pp][s] :
+%       ok := false ; % not yet defined
+%     elseif spotcolorhash[pp][s] = -1 :
+%       ok := false ; % locally defined and undefined
+%     else :
+%       ok := true ;  % globally already defined
+%     fi ;
+%     if not ok :
+%       save ss ; string ss ; ss := p & " " & decimal s ;
+%       _spotcolor_counter_ := _spotcolor_counter_ + 1 ;
+%       spotcolorpattern[_spotcolor_counter_/1000] := ss ;
+%       spotcolorhash[pp][s] := _spotcolor_counter_ ;
+%       flush_special(2, 5, decimal _spotcolor_counter_ & " " & ss) ;
+%       _local_specials_ := _local_specials_ &
+%         "spotcolorhash["&decimal pp&"]["&decimal s&"]:=-1;" ;
+%     fi ;
+%     (_special_signal_/1000,2/1000,spotcolorhash[pp][s]/1000)
+%   else :
+%     (1-s,1-s,1-s)
+%   fi
+% enddef ;
+
+vardef spotcolor(expr p, s) =
+  multitonecolor(p, 1, "", decimal s)
+enddef ;
+
+vardef multitonecolor(expr n, f, d, p) = % name fractions names factors
+  if spotcolors :
+    save ok, pc_tag ; boolean ok ; string pc_tag ;
+    pc_tag := "_pct_" & n ;
+    if not unstringed(pc_tag) :
+      _spotcolor_number_ := _spotcolor_number_ + 1 ;
+      setunstringed(pc_tag,_spotcolor_number_) ;
+    fi ;
+    pp := getunstringed(pc_tag) ;
+    pc_tag := "_pct_"& decimal f & "_" & if d = "" : n else : d fi & "_" & p ; % check for d empty
+    if not unstringed(pc_tag) :
+      _spotcolor_number_ := _spotcolor_number_ + 1 ;
+      setunstringed(pc_tag,_spotcolor_number_) ;
+    fi ;
+    ps := getunstringed(pc_tag) ;
+    if unknown spotcolorhash[pp][ps] :
+      ok := false ; % not yet defined
+    elseif spotcolorhash[pp][ps] = -1 :
+      ok := false ; % locally defined and undefined
+    else :
+      ok := true ;  % globally already defined
+    fi ;
+    if not ok :
+      save ss ; string ss ; ss := n & " " & decimal f & " " & if d = "" : n else : d fi & " " & p ;
+      _spotcolor_counter_ := _spotcolor_counter_ + 1 ;
+      spotcolorpattern[_spotcolor_counter_/1000] := ss ;
+      spotcolorhash[pp][ps] := _spotcolor_counter_ ;
+      flush_special(2, 7, decimal _spotcolor_counter_ & " " & ss) ;
+      _local_specials_ := _local_specials_ &
+        "spotcolorhash["&decimal pp&"]["&decimal ps&"]:=-1;" ;
+    fi ;
+    (_special_signal_/1000,2/1000,spotcolorhash[pp][ps]/1000)
+  else :
+   .5white
+  fi
+enddef ;
+
+%D Transparency
+
+normaltransparent     :=  1 ; multiplytransparent   :=  2 ;
+screentransparent     :=  3 ; overlaytransparent    :=  4 ;
+softlighttransparent  :=  5 ; hardlighttransparent  :=  6 ;
+colordodgetransparent :=  7 ; colorburntransparent  :=  8 ;
+darkentransparent     :=  9 ; lightentransparent    := 10 ;
+differencetransparent := 11 ; exclusiontransparent  := 12 ;
+
+% nottransparent        :=  0 ;
+% compatibletransparent := 99 ;
+
+% fill fullcircle scaled 10cm withcolor transparant(.8,3,color) ;
+
+% vardef transparent(expr n, t, c) =
+%   save s, ss, nn, cc, is_cmyk, is_spot, ok ;
+%   string s, ss ; numeric nn ; color cc ; boolean is_cmyk, is_spot, ok ;
+%   % transparancy type
+%   if string n :
+%     if expandafter known scantokens(n&"transparent") :
+%       nn := scantokens(n&"transparent") ;
+%     else :
+%       nn := 0 ;
+%     fi
+%   else : % nn := min(n,13)
+%     nn := if n<13 : n else : nn := 0 fi ;
+%   fi ;
+%   % we need to expand the color (can be cmyk(..) or predefined)
+%   cc := c ; % expand color
+%   % check for cmyk special
+%   is_cmyk := (redpart   cc = _special_signal_/1000)
+%          and (greenpart cc = 1/1000) ;
+%   is_spot := (redpart   cc = _special_signal_/1000)
+%          and (greenpart cc = 2/1000) ;
+%   % build special string, fetch cmyk components
+%   s := decimal nn & " " & decimal t & " " &
+%        if     is_cmyk : cmykcolorpattern[bluepart cc]
+%        elseif is_spot : spotcolorpattern[bluepart cc]
+%        else           : dddecimal cc fi ;
+%   % check if this one is already used
+%   ss := "tr_" & s ;
+%   % efficiency hack
+%   if expandafter unknown scantokens(ss) :
+%     ok := false ; % not yet defined
+%   elseif scantokens(ss) < 0  :
+%     ok := false ; % locally defined and undefined
+%   else :
+%     ok := true ;  % globally already defined
+%   fi ;
+%   if not ok :
+%     if is_spot  :
+%       flush_special(5, 6, s) ;
+%     elseif is_cmyk :
+%       flush_special(4, 8, s) ;
+%     else :
+%       flush_special(3, 7, s) ;
+%     fi ;
+%     scantokens(ss) := _special_counter_ ;
+%     _local_specials_ := _local_specials_ &
+%       "scantokens(" & ditto & ss & ditto & ") := -1 ;" ;
+%   fi ;
+%   % go ahead
+%   if is_spot :
+%     (_special_signal_/1000,5/1000,scantokens(ss)/1000)
+%   elseif is_cmyk :
+%     (_special_signal_/1000,4/1000,scantokens(ss)/1000)
+%   else :
+%     (_special_signal_/1000,3/1000,scantokens(ss)/1000)
+%   fi
+% enddef ;
+
+vardef transparent(expr n, t, c) =
+  save s, ss, nn, cc, is_cmyk, is_spot, ok ;
+  string s, ss ; numeric nn ; color cc ; boolean is_cmyk, is_spot, ok ;
+  % transparancy type
+  if string n :
+    if expandafter known scantokens(n&"transparent") :
+      nn := scantokens(n&"transparent") ;
+    else :
+      nn := 0 ;
+    fi
+  else : % nn := min(n,13)
+    nn := if n<13 : n else : nn := 0 fi ;
+  fi ;
+  % we need to expand the color (can be cmyk(..) or predefined)
+  cc := c ; % expand color
+  % check for cmyk special
+  is_cmyk := (redpart   cc = _special_signal_/1000)
+         and (greenpart cc = 1/1000) ;
+  is_spot := (redpart   cc = _special_signal_/1000)
+         and (greenpart cc = 2/1000) ;
+  % build special string, fetch cmyk components
+  s := decimal nn & " " & decimal t & " " &
+       if     is_cmyk : cmykcolorpattern[bluepart cc]
+       elseif is_spot : spotcolorpattern[bluepart cc]
+       else           : dddecimal cc fi ;
+  % check if this one is already used
+  ss := cleanstring("tr_" & s) ;
+  % we now have rather unique names, i.e. a color spec of .234 becomes
+  % tr..._234.... and metapost gives a number overflow (parse error)
+  % for variables like tr_12345678 which may result from many decimal
+  % positions (imo mp bug)
+  ss := asciistring(ss) ;
+  % efficiency hack
+  if expandafter unknown scantokens(ss) :
+    ok := false ; % not yet defined
+  elseif scantokens(ss) < 0  :
+    ok := false ; % locally defined and undefined
+  else :
+    ok := true ;  % globally already defined
+  fi ;
+  if not ok :
+    if is_spot  :
+      flush_special(5, 8, s) ;
+    elseif is_cmyk :
+      flush_special(4, 8, s) ;
+    else :
+      flush_special(3, 7, s) ;
+    fi ;
+    scantokens(ss) := _special_counter_ ;
+    _local_specials_ := _local_specials_ &
+      "scantokens(" & ditto & ss & ditto & ") := -1 ;" ;
+  fi ;
+  % go ahead
+  if is_spot :
+    (_special_signal_/1000,5/1000,scantokens(ss)/1000)
+  elseif is_cmyk :
+    (_special_signal_/1000,4/1000,scantokens(ss)/1000)
+  else :
+    (_special_signal_/1000,3/1000,scantokens(ss)/1000)
+  fi
+enddef ;
+
+%D This function returns true of false, dependent on transparency.
+
+vardef is_transparent(text t) =
+  begingroup ; save transparent ; save _c_, _b_ ;
+    vardef transparent(expr nn, tt, cc) = _b_ := true ; cc enddef ;
+    boolean _b_ ; _b_ := false ;
+    color _c_ ; _c_ := t ; _b_
+  endgroup
+enddef ;
+
+%D This function returns the not transparent color.
+
+vardef not_transparent(text t) =
+  begingroup ; save transparent ;
+  vardef transparent(expr nn, tt, cc) = cc enddef ;
+  t endgroup
+enddef ;
+
+%D Basic position tracking:
+
+def register (expr label, width, height, offset) =
+  begingroup ;
+  flush_special(50, 7,
+    ddecimal offset & " " &
+    decimal  width  & " " &
+    decimal  height & " " & label) ;
+  endgroup ;
+enddef ;
+
+%D We cannot scale cmyk colors directly since this spoils
+%D the trigger signal (such colors are no real colors).
+
+vardef scaledcmyk(expr c,m,y,k,sf) =
+  cmyk(sf*c,sf*m,sf*y,sf*k)
+enddef ;
+
+vardef scaledcmykasrgb(expr c,m,y,k,sf) =
+  (sf*(1-c-k,1-m-k,1-y-k))
+enddef ;
+
+vardef scaledrgbascmyk(expr c,m,y,k,sf) =
+  scaledcmyk(1-c,1-m,1-y,0,sf)
+enddef ;
+
+vardef scaledrgb(expr r,g,b,sf) =
+  (sf*(r,g,b))
+enddef ;
+
+vardef scaledgray(expr s,sf) =
+  (sf*(s,s,s))
+enddef ;
+
+% spotcolor is already scaled
+
+endinput ;
+
+% just an exercise (due to a question by Chof on the context mailing list); scaling of
+% 'special' colors is not possible and the next solution is incomplete (spot colors,
+% transparency, etc); watch the the tricky chained macro construction
+
+% vardef normalgray(expr s      ) = (s,s,s) enddef ;
+% vardef normalrgb (expr r,g,b  ) = (r,g,b) enddef ;
+% vardef normalcmyk(expr c,m,y,k) = if cmykcolors : save ok ; boolean ok ; if unknown cmykcolorhash[c][m][y][k] : ok := false ; elseif cmykcolorhash[c][m][y][k] = -1 : ok := false ; else : ok := true ; fi ; if not ok : save s ; string s ; s := dddecimal (c,m,y) & " " & decimal k ; _cmyk_counter_ := _cmyk_counter_ + 1 ; cmykcolorpattern[_cmyk_counter_/1000] := s ; cmykcolorhash[c][m][y][k] := _cmyk_counter_ ; flush_special(1, 7, decimal _cmyk_counter_ & " " & s) ; _local_specials_ := _local_specials_ & " cmykcolorhash[" & decimal c & "][" & decimal m & "][" & decimal y & "][" & decimal k & "] := -1 ; " ; fi ; (_special_signal_/1000,1/1000,cmykcolorhash[c][m][y][k]/1000) else : (1-c-k,1-m-k,1-y-k) fi enddef ;
+
+% vardef gray(expr s)       = normalgray(s      ) enddef ;
+% vardef rgb (expr r,g,b)   = normalrgb (r,g,b  ) enddef ;
+% vardef cmyk(expr c,m,y,k) = normalcmyk(c,m,y,k) enddef ;
+
+% numeric _scaled_color_t_ ;
+% color   _scaled_color_c_ ;
+
+% def withscaledcolor =
+%     hide (
+%         _scaled_color_t_ := 0 ; % direct
+%         def gray(expr s) =
+%             hide (
+%                 _gray_s_ := s ;
+%                 _scaled_color_t_ := 1; % gray
+%             )
+%             0
+%         enddef ;
+%         def rgb (expr r,g,b) =
+%             hide (
+%                 _rgb_r_ := r ; _rgb_g_ := g ; _rgb_b_ := b ;
+%                 _scaled_color_t_ := 2 ; % rgb
+%             )
+%             0
+%         enddef ;
+%         def cmyk (expr c,m,y,k) =
+%             hide (
+%                 _cmyk_c_ := c ; _cmyk_m_ := m ; _cmyk_y_ := y ; _cmyk_k_ := k ;
+%                 _scaled_color_t_ := 3 ; % cmyk
+%             )
+%             0
+%         enddef ; )
+%     dowithscaledcolor
+% enddef ;
+
+% def dowithscaledcolor expr t =
+%     hide (
+%         if color t : _scaled_color_c_ := t fi ;
+%         vardef gray(expr s)       = normalgray(s)       enddef ;
+%         vardef rgb (expr r,g,b)   = normalrgb (r,g,b)   enddef ;
+%         vardef cmyk(expr c,m,y,k) = normalcmyk(c,m,y,k) enddef ;
+%     )
+% enddef ;
+
+% def by expr s =
+%     if     _scaled_color_t_ = 0 :
+%         withcolor s*_scaled_color_c_
+%     elseif _scaled_color_t_ = 1 :
+%         withcolor gray(s*_gray_s_)
+%     elseif _scaled_color_t_ = 2 :
+%         withcolor rgb (s*_rgb_r_, s*_rgb_g_, s*_rgb_b_)
+%     elseif _scaled_color_t_ = 3 :
+%         withcolor cmyk(s*_cmyk_c_, s*_cmyk_m_, s*_cmyk_y_, s*_cmyk_k_)
+%     fi
+% enddef ;
+
+% fill fullcircle scaled 10cm withscaledcolor cmyk(0,0,1,0) by .5 ;
+% fill fullcircle scaled  8cm withscaledcolor rgb (0,0,1)   by .5 ;
+% fill fullcircle scaled  6cm withscaledcolor gray(1)       by .5 ;
+% fill fullcircle scaled  4cm withscaledcolor     (0,1,0)   by .5 ;
diff --git a/Master/texmf-dist/metapost/context/base/mp-step.mp b/Master/texmf-dist/metapost/context/base/mp-step.mp
new file mode 100644
index 00000000000..d602f701430
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-step.mp
@@ -0,0 +1,320 @@
+%D \module
+%D   [       file=mp-step.mp,
+%D        version=2001.05.22,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=steps,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_step : endinput         ; fi ;
+
+boolean context_step ; context_step := true ;
+
+%D In the associated \TEX\ module \type {m-steps}, we describe
+%D three methods. The first method uses a different kind of
+%D code than the other two. The method we decided to use,
+%D is based on positional information (paths) provided by
+%D \CONTEXT.
+
+def initialize_step_variables =
+  save line_method, line_h_offset, line_v_offset ;
+  numeric line_method   ; line_method   := 1 ;
+  numeric line_h_offset ; line_h_offset := 3pt ;
+  numeric line_v_offset ; line_v_offset := 3pt ;
+enddef ;
+
+def begin_step_chart =
+  initialize_step_variables ;
+  save steps, texts, t, b, tb, nofcells ;
+  picture cells[][], texts[][][], lines[][][] ;
+  numeric t, b ; t := 1 ; b := 2 ;
+  numeric nofcells ; nofcells := 0 ;
+enddef ;
+
+def analyze_step_chart =
+  numeric n[], l[][], r[][] ; pair p[] ;
+  n[t] := n[b] := 0 ; numeric tb ; 
+  for i=1 upto nofcells : for nn = t, b :
+    if bbwidth(cells[nn][i])>0 : n[nn] := n[nn] + 1 ; fi ;
+    l[t][i] := r[t][i] := l[b][i] := r[b][i] := 0 ;
+  endfor ; endfor ;
+  % count left and right points
+  for i=1 upto nofcells-1 : for j=i upto nofcells-1 : for nn = t, b :
+    if bbwidth(texts[nn][i][j])>0 :
+      l[nn][i] := l[nn][i] + 1 ;
+      r[nn][j+1] := r[nn][j+1] + 1 ;
+    fi ;
+  endfor ; endfor ; endfor ;
+  % calculate left and right points
+  vardef do (expr nn, mm, ii, ss) =
+    if (l[nn][ii] + r[nn][ii]) > 1 : ss else : .5 fi
+      [ ulcorner cells[mm][ii], urcorner cells[mm][ii] ]
+  enddef ;
+  % combined rows
+  tb := if n[t]>0 : t else : b fi ;
+enddef ;
+
+vardef get_step_chart_top_line (expr i, j) =
+  if bbwidth(cells[tb][i])>0 :
+    if bbwidth(texts[t][i][j])>0 :
+      if bbwidth(cells[tb][j+1])>0 :
+        p[1] := top do(t, tb,   i, .6) ;
+        p[3] := top do(t, tb, j+1, .4) ;
+        p[2] := .5[p[1],p[3]] ;
+        if line_method = 1 :
+          p[2] := p[2] shifted (0, ypart
+            (llcorner texts[t][i][j] - ulcorner cells[tb][j+1])) ;
+        elseif line_method = 2 :
+          p[2] := center texts[t][i][j] ;
+        else :
+          % nothing
+        fi ;
+        p[1] := p[1] shifted (0,+line_v_offset) ;
+        p[2] := p[2] shifted (0,-line_v_offset) ;
+        p[3] := p[3] shifted (0,+line_v_offset) ;
+        (p[1] {up} ... p[2] ... {down} p[3])
+      else :
+        origin 
+      fi 
+    else :
+      origin 
+    fi 
+  else :
+    origin 
+  fi 
+enddef ; 
+
+vardef get_step_chart_bot_line (expr i, j) =
+  if bbwidth(cells[b][i])>0 :
+    if bbwidth(texts[b][i][j])>0 :
+      if bbwidth(cells[b][j+1])>0 :
+        p[1] := (bot do(b, b,   i, .6)) shifted (0,-bbheight(cells[b][i])) ;
+        p[3] := (bot do(b, b, j+1, .4)) shifted (0,-bbheight(cells[b][j+1])) ;
+        p[2] := .5[p[1],p[3]] ;
+        if line_method = 1 :
+          p[2] := p[2] shifted (0, -ypart
+            (llcorner cells[b][j+1] - ulcorner texts[b][i][j])) ;
+        elseif line_method = 2 :
+          p[2] := center texts[b][i][j] ;
+        fi ;
+        p[1] := p[1] shifted (0,-line_v_offset) ;
+        p[2] := p[2] shifted (0,+line_v_offset) ;
+        p[3] := p[3] shifted (0,-line_v_offset) ;
+        (p[1] {down} ... p[2] ... {up} p[3])
+      else :
+        origin 
+      fi 
+    else :
+      origin 
+    fi 
+  else :
+    origin 
+  fi 
+enddef ;
+
+def end_step_chart =
+  for i=1 upto nofcells :                         for nn = t, b : 
+      if bbwidth(cells[nn][i])   >0 : draw cells[nn][i]    ; fi ; 
+  endfor ;          endfor ;
+  for i=1 upto nofcells : for j=i upto nofcells : for nn = t, b : 
+    if known lines[nn][i][j] :
+      if bbwidth(lines[nn][i][j])>0 : draw lines[nn][i][j] ; fi ;
+    fi ; 
+  endfor ; endfor ; endfor ;
+  for i=1 upto nofcells : for j=i upto nofcells : for nn = t, b :
+      if bbwidth(texts[nn][i][j])>0 : draw texts[nn][i][j] ; fi ;
+  endfor ; endfor ; endfor ;
+enddef ;
+
+%D Step tables. 
+
+def begin_step_table =
+  initialize_step_variables ;
+  picture cells[], texts[], lines[] ;
+  numeric nofcells ; nofcells := 0 ;
+enddef ;
+
+def end_step_table =
+  for i=1 upto nofcells : if known cells[i] : if bbwidth(cells[i])>0 : 
+    draw cells[i] ; 
+  fi ; fi ; endfor ;
+  for i=1 upto nofcells : if known lines[i] : if bbwidth(lines[i])>0 : 
+    draw lines[i] ; 
+  fi ; fi ; endfor ;
+  for i=1 upto nofcells : if known texts[i] : if bbwidth(texts[i])>0 : 
+    draw texts[i] ;
+  fi ; fi ; endfor ;
+enddef ;
+
+vardef get_step_table_line (expr i) =
+  pair prev, self, next ;
+  if known texts[i] :
+    self := lft .5[llcorner texts[i], ulcorner texts[i] ] ;
+    prev := rt if known texts[i-1] : .3 else : .5 fi [lrcorner cells[i]  , urcorner cells[i]  ] ;
+    next := rt if known texts[i+1] : .7 else : .5 fi [lrcorner cells[i+1], urcorner cells[i+1]] ;
+    self := self shifted (-line_h_offset,0) ;
+    prev := prev shifted (+line_h_offset,0) ;
+    next := next shifted (+line_h_offset,0) ;
+    prev {right} ... self ... {left} next
+  else :
+    origin
+  fi
+enddef ;
+
+endinput
+
+%D The older method let \METAPOST\ do the typesetting. The
+%D macros needed for that are included here for educational
+%D purposes.
+%D
+%D \starttypen
+%D def initialize_step_variables =
+%D   save line_color, line_width, arrow_alternative,
+%D     text_fill_color, text_line_color, text_line_width, text_offset,
+%D     cell_fill_color, cell_line_color, cell_line_width, cell_offset,
+%D     line_h_offset, line_v_offset ;
+%D   color   line_color       ; line_color       := .4white ;
+%D   numeric line_width       ; line_width       := 1.5pt ;
+%D   color   text_fill_color  ; text_fill_color  := white ;
+%D   color   text_line_color  ; text_line_color  := red ;
+%D   numeric text_line_width  ; text_line_width  := 1pt ;
+%D   numeric text_offset      ; text_offset      := 2pt ;
+%D   color   cell_fill_color  ; cell_fill_color  := white ;
+%D   color   cell_line_color  ; cell_line_color  := blue ;
+%D   numeric cell_line_width  ; cell_line_width  := 1pt ;
+%D   numeric cell_offset      ; cell_offset      := 2pt ;
+%D   numeric line_alternative ; line_alternative := 1 ;
+%D   numeric line_h_offset    ; line_h_offset    := 3pt ;
+%D   numeric line_v_offset    ; line_v_offset    := 3pt ;
+%D enddef ;
+%D
+%D def begin_step_chart =
+%D   begingroup ;
+%D   initialize_step_variables ;
+%D   save steps, texts, t, b ;
+%D   picture cells[][]   ; numeric nofcells ; nofcells := 0 ;
+%D   picture texts[][][] ; numeric noftexts ; noftexts := 0 ;
+%D   numeric t, b ; t := 1 ; b := 2 ;
+%D enddef ;
+%D \stoptypen
+%D
+%D We use a couple of macros to store the content. In the
+%D second (third) alternative we will directly fill the
+%D cells.
+%D
+%D \starttypen
+%D def set_step_chart_cells (expr one, two) =
+%D   nofcells := nofcells + 1 ; noftexts := 0 ;
+%D   cells[t][nofcells] := textext.rt(one) ;
+%D   cells[b][nofcells] := textext.rt(two) ;
+%D enddef ;
+%D
+%D def set_step_chart_texts (expr one, two) =
+%D   noftexts := noftexts + 1 ;
+%D   texts[t][nofcells][noftexts] := textext.rt(one) ;
+%D   texts[b][nofcells][noftexts] := textext.rt(two) ;
+%D enddef ;
+%D \stoptypen
+%D
+%D If you compare the building macro with the later
+%D alternative, you will notice that here we explicitly
+%D have to calculate the distances and positions.
+%D
+%D \starttypen
+%D def end_step_chart =
+%D   numeric dx ; dx :=  0 ; path p ;
+%D   numeric n[] ; n[t] := n[b] := 0 ;
+%D   numeric stepsvdistance[] ;
+%D   vardef bbwidth  (expr p) = (xpart (lrcorner p - llcorner p)) enddef ;
+%D   vardef bbheight (expr p) = (ypart (urcorner p - lrcorner p)) enddef ;
+%D   stepsvdistance[t] := stepsvdistance[b] := 0 ;
+%D   for i=1 upto nofcells :
+%D     % find largest bbox
+%D     p := boundingbox steps
+%D       [if bbwidth(cells[t][i])>bbwidth(cells[b][i]): t else: b fi][i] ;
+%D     % assign largest bbox
+%D     for nn = t, b :
+%D       if bbwidth(cells[nn][i])>0 :
+%D         setbounds cells[nn][i] to p enlarged cell_offset ;
+%D         n[nn] := n[nn] + 1 ;
+%D       fi ;
+%D     endfor ;
+%D     % determine height
+%D     if n[t]>0 :
+%D       stepsvdistance[t] := bbheight(cells[t][1]) + intertextdistance ;
+%D     fi ;
+%D     % add to row
+%D     for nn = t, b :
+%D       cells[nn][i] := cells[nn][i] shifted (dx,stepsvdistance[nn]) ;
+%D       if bbwidth(cells[nn][i])>0 :
+%D         dowithpath (boundingbox cells[nn][i],
+%D           cell_line_width, cell_line_color, cell_background_color) ;
+%D       fi ;
+%D     endfor ;
+%D     % calculate position
+%D     dx := dx + interstepdistance + bbwidth(cells[b][i]) ;
+%D   endfor ;
+%D   boolean stacked ; stacked := false ;
+%D   numeric l[][], r[][], l[][], r[][] ;
+%D   pair pa, pb, pc ; path p[] ;
+%D   for i=1 upto nofcells :
+%D     l[t][i] := r[t][i] := l[b][i] := r[b][i] := 0 ;
+%D   endfor ;
+%D   % count left and right points
+%D   for i=1 upto nofcells : for j=1 upto nofcells : for nn = t, b :
+%D     if known texts[nn][i][j] : if bbwidth(texts[nn][i][j])>0 :
+%D       l[nn][i]   := l[nn][i]   + 1 ;
+%D         r[nn][j+i] := r[nn][j+i] + 1 ;
+%D         stacked := (stacked or (j>1)) ;
+%D         setbounds texts[nn][i][j] to boundingbox texts[nn][i][j] enlarged cell_offset ;
+%D     fi fi ;
+%D     endfor ; endfor ; endfor ;
+%D     % calculate left and right points
+%D     vardef do (expr nn, mm, ii, ss) =
+%D       if (l[nn][ii] > 0) and (r[nn][ii] > 0) : ss else : .5 fi
+%D         [ ulcorner cells[mm][ii],urcorner cells[mm][ii] ]
+%D     enddef ;
+%D     % draw arrow from left to right point
+%D     def dodo (expr nn, ii, jj, dd) =
+%D       drawarrow p[nn]
+%D         withpen pencircle scaled arrow_line_width
+%D         withcolor arrow_line_color ;
+%D       transform tr ; tr := identity
+%D         shifted point .5 along p[nn]
+%D         shifted -center texts[nn][ii][jj]
+%D         if not stacked : shifted (0,dd) fi ;
+%D         dowithpath ((boundingbox texts[nn][ii][jj]) transformed tr,
+%D           text_line_width, text_line_color, text_fill_color) ;
+%D     enddef ;
+%D     % draw top and bottom text boxes
+%D     for i=1 upto nofcells : for j=1 upto nofcells :
+%D       pickup pencircle scaled arrow_line_width ;
+%D       if known texts[t][i][j] : if bbwidth(texts[t][i][j]) > 0 :
+%D         pa := top do(t, if n[t]>0 : t else : b fi,   i, .6) ;
+%D         pb := top do(t, if n[t]>0 : t else : b fi, j+i, .4) ;
+%D         pc := .5[pa,pb] shifted (0,+step_arrow_depth) ;
+%D         p[t] := pa {up} .. if not stacked : pc .. fi {down} pb ;
+%D         dodo(t, i, j, +intertextdistance) ;
+%D       fi fi ;
+%D       if known texts[b][i][j] : if bbwidth(texts[b][i][j]) > 0 :
+%D         pa := (bot do(b, b,   i, .6)) shifted (0,-bbheight(cells[b][i])) ;
+%D         pb := (bot do(b, b, j+i, .4)) shifted (0,-bbheight(cells[b][j+i])) ;
+%D         pc := .5[pa,pb] shifted (0,-step_arrow_depth) ;
+%D         p[b] := pa {down} .. if not stacked : pc .. fi {up} pb ;
+%D         dodo(b, i, j, -intertextdistance) ;
+%D       fi fi ;
+%D     endfor ; endfor ;
+%D   endgroup ;
+%D enddef ;
+%D \stoptypen
+%D
+%D If you compare both methods, you will notice that the
+%D first method is the cleanest, but not the most efficient
+%D (since it needs \TEX\ runs within \METAPOST\ runs within
+%D \TEX\ runs).
diff --git a/Master/texmf-dist/metapost/context/base/mp-symb.mp b/Master/texmf-dist/metapost/context/base/mp-symb.mp
new file mode 100644
index 00000000000..a84c84e828d
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-symb.mp
@@ -0,0 +1,351 @@
+%D \module
+%D   [       file=mp-symb.mp,
+%D        version=very old,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=navigation symbol macros,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+%D Instead of these symbols, you can use the \type {contnav}
+%D font by Taco Hoekwater that is derived form this file. 
+
+u  := 3;
+h  := 5u;
+wt := 5u;
+wb := .25wt;
+o  := .1u;
+pw := .5u;
+
+drawoptions (withpen pencircle scaled pw);
+
+path lefttriangle, righttriangle, sublefttriangle, subrighttriangle;
+
+pair s ; s = (2wb,0) ;
+
+x1t = x2t = 0;
+x3t = wt;
+y3t = .5h;
+z1t-z2t = (z3t-z2t) rotated 60;
+
+z4t = (z2t--z3t) intersectionpoint ((z1t--z2t) shifted s) ;
+z5t = (z3t--z1t) intersectionpoint ((z1t--z2t) shifted s) ;
+
+righttriangle = z1t--z2t--z3t--cycle;
+lefttriangle = righttriangle rotatedaround((0,.5h), 180) shifted (wt,0);
+
+subrighttriangle = z4t--((z2t--z3t--z1t) shifted s)--z5t ;
+sublefttriangle  = subrighttriangle rotatedaround((0,.5h), 180) shifted (wt,0);
+
+path sidebar;
+
+x1b = x4b = 0;
+x2b = x3b = wb;
+y1b = y2b = y1t;
+y3b = y4b = y2t;
+
+sidebar = z1b--z2b--z3b--z4b--cycle;
+
+path midbar, onebar, twobar;
+
+hh = abs(y1t-y2t);
+
+%midbar := unitsquare scaled 2hh/3;
+midbar := unitsquare scaled hh;
+onebar := unitsquare xscaled (hh/3) yscaled hh;
+twobar := onebar;
+
+def prepareglyph =
+  drawoptions (withpen pencircle scaled .5u);
+enddef;
+
+def finishglyph =
+  set_outer_boundingbox currentpicture;
+  bboxmargin := o;
+  setbounds currentpicture to bbox currentpicture;
+%  draw boundingbox currentpicture withcolor red withpen pencircle scaled 1;
+enddef;
+
+beginfig  (1);
+  prepareglyph;
+  fill lefttriangle;
+  draw lefttriangle;  % draw gets the bbox right, filldraw doesn't
+  finishglyph;
+endfig;
+
+beginfig  (2);
+  prepareglyph;
+  fill righttriangle;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig  (3);
+  prepareglyph;
+  fill sidebar;
+  draw sidebar;
+  fill lefttriangle shifted (.5s);
+  draw lefttriangle shifted (.5s);
+  finishglyph;
+endfig;
+
+beginfig  (4);
+  prepareglyph;
+  fill righttriangle;
+  draw righttriangle;
+  fill sidebar shifted (wt,0);
+  draw sidebar shifted (wt,0);
+  finishglyph;
+endfig;
+
+beginfig  (5);
+  prepareglyph;
+  fill lefttriangle;
+  draw lefttriangle;
+  fill lefttriangle shifted s;
+  draw lefttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig  (6);
+  prepareglyph;
+  fill righttriangle;
+  draw righttriangle;
+  fill righttriangle shifted s;
+  draw righttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig  (7);
+  prepareglyph;
+  fill midbar;
+  draw midbar;
+  finishglyph;
+endfig;
+
+beginfig  (8);
+  prepareglyph;
+  fill onebar;
+  draw onebar;
+  finishglyph;
+endfig;
+
+beginfig  (9);
+  prepareglyph;
+  fill twobar;
+  draw twobar;
+  fill twobar shifted (pw+hh/2,0);
+  draw twobar shifted (pw+hh/2,0);
+  finishglyph;
+endfig;
+
+beginfig(101);
+  prepareglyph;
+  draw lefttriangle;
+  finishglyph;
+endfig;
+
+beginfig(102);
+  prepareglyph;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig(103);
+  prepareglyph;
+  draw sidebar;
+  draw lefttriangle shifted (.5s);
+  finishglyph;
+endfig;
+
+beginfig(104);
+  prepareglyph;
+  draw righttriangle;
+  draw sidebar shifted (wt,0);
+  finishglyph;
+endfig;
+
+beginfig(105);
+  prepareglyph;
+  draw lefttriangle;
+  draw lefttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig(106);
+  prepareglyph;
+  draw righttriangle;
+  draw righttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig(107);
+  prepareglyph;
+  draw midbar;
+  finishglyph;
+endfig;
+
+beginfig(108);
+  prepareglyph;
+  draw onebar;
+  finishglyph;
+endfig;
+
+beginfig(109);
+  prepareglyph;
+  draw twobar;
+  draw twobar shifted (pw+hh/2,0);
+  finishglyph;
+endfig;
+
+beginfig(201);
+  prepareglyph;
+  draw lefttriangle;
+  finishglyph;
+endfig;
+
+beginfig(202);
+  prepareglyph;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig(203);
+  prepareglyph;
+  draw sidebar;
+  draw lefttriangle shifted (.5s);
+  finishglyph;
+endfig;
+
+beginfig(204);
+  prepareglyph;
+  draw righttriangle;
+  draw sidebar shifted (wt,0);
+  finishglyph;
+endfig;
+
+beginfig(205);
+  prepareglyph;
+  draw sublefttriangle shifted s;
+  draw lefttriangle shifted s;
+  finishglyph;
+endfig;
+
+beginfig(206);
+  prepareglyph;
+  draw subrighttriangle;
+  draw righttriangle;
+  finishglyph;
+endfig;
+
+beginfig(207);
+  prepareglyph;
+  draw midbar;
+  finishglyph;
+endfig;
+
+beginfig(208);
+  prepareglyph;
+  draw onebar;
+  finishglyph;
+endfig;
+
+beginfig(209);
+  prepareglyph;
+  draw twobar;
+  draw twobar shifted (pw+hh/2,0);
+  finishglyph;
+endfig;
+
+
+beginfig(999);
+
+picture collection []  ; 
+
+prepareglyph ; 
+draw lefttriangle ; 
+finishglyph ;
+collection[201] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ; 
+draw righttriangle ; 
+finishglyph ;
+collection[202] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ; 
+draw sidebar ; 
+draw lefttriangle shifted (.5s) ;
+finishglyph ;
+collection[203] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ; 
+draw righttriangle ; 
+draw sidebar shifted (wt,0) ; 
+finishglyph ;
+collection[204] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ; 
+draw sublefttriangle shifted s ; 
+draw lefttriangle shifted s ;
+finishglyph ;
+collection[205] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ;
+draw subrighttriangle ;
+draw righttriangle ;
+finishglyph ;
+collection[206] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ;
+draw midbar ;
+finishglyph ;
+collection[207] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ;
+draw onebar ;
+finishglyph ;
+collection[208] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+prepareglyph ;
+draw twobar ;
+draw twobar shifted (pw+hh/2,0) ;
+finishglyph ;
+collection[209] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+for i=201 upto 209 : 
+  collection[i] := collection[i] shifted - center collection[i] ;
+endfor ; 
+
+addto currentpicture also collection[205] shifted (   0,   0) 
+  withcolor (.3,.4,.5) ;
+addto currentpicture also collection[202] shifted (   0,1.5h) 
+  withcolor (.5,.6,.7) ;
+addto currentpicture also collection[201] shifted (1.5h,   0) 
+  withcolor (.6,.7,.8) ;
+addto currentpicture also collection[206] shifted (1.5h,1.5h) 
+  withcolor (.4,.5,.6) ;
+
+collection[210] := currentpicture ; 
+currentpicture := nullpicture ; 
+
+bboxmargin := .25u; 
+
+fill bbox collection[210] withcolor .95(1,1,0);
+addto currentpicture also collection[210] ; 
+
+endfig ; 
+
+end
diff --git a/Master/texmf-dist/metapost/context/base/mp-text.mp b/Master/texmf-dist/metapost/context/base/mp-text.mp
new file mode 100644
index 00000000000..2e061df0996
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-text.mp
@@ -0,0 +1,267 @@
+%D \module
+%D   [       file=mp-text.mp,
+%D        version=2000.07.10,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=text support,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See licen-en.pdf for
+%C details.
+
+%D Under construction.
+
+if unknown context_tool :    input mp-tool ; fi ;
+if   known context_text : endinput         ; fi ;
+
+boolean context_text ; context_text := true ;
+
+if unknown noftexpictures :
+  numeric noftexpictures ; noftexpictures := 0 ;
+fi ;
+
+if unknown texpictures[1] :
+  picture texpictures[] ;
+fi ;
+
+numeric textextoffset ; textextoffset := 0 ;
+
+% vardef textext@#(expr txt) =
+%   interim labeloffset := textextoffset ;
+%   noftexpictures := noftexpictures + 1 ;
+%   if string txt :
+%     write "% figure " & decimal charcode & " : " &
+%       "texpictures[" & decimal noftexpictures & "] := btex " &
+%       txt & " etex ;" to jobname & ".mpt" ;
+%     if unknown texpictures[noftexpictures] :
+%       thelabel@#("unknown",origin)
+%     else :
+%       thelabel@#(texpictures[noftexpictures],origin)
+%     fi
+%   else :
+%     thelabel@#(txt,origin)
+%   fi
+% enddef ;
+
+boolean hobbiestextext ; hobbiestextext := false ;
+% string  textextstring  ; textextstring  := "" ;
+
+% def resettextextdirective =
+%   textextstring := "" ;
+% enddef ;
+
+% def textextdirective text t =
+%   textextstring := textextstring & t ;
+% enddef ;
+
+vardef textext@#(expr txt) =
+  save _s_ ; string _s_ ;
+  interim labeloffset := textextoffset ;
+  noftexpictures := noftexpictures + 1 ;
+  if string txt :
+%     if textextstring <> "" :
+%       _s_ := "verbatimtex " & textextstring & " etex ;" ;
+%     else :
+%       _s_ := "" ;
+%     fi ;
+    if hobbiestextext : % the tex.mp method as fallback (see tex.mp)
+%       write _s_ to "mptextmp.mp" ;
+      write _s_ & "btex " & txt & " etex" to "mptextmp.mp" ;
+      write EOF to "mptextmp.mp" ;
+      scantokens "input mptextmp"
+    else :
+%       write "% setup : " & _s_ to jobname & ".mpt" ;
+      write "% figure " & decimal charcode & " : " &
+        "texpictures[" & decimal noftexpictures & "] := btex " &
+        txt & " etex ;" to jobname & ".mpt" ;
+      if unknown texpictures[noftexpictures] :
+        thelabel@#("unknown",origin)
+      else :
+        thelabel@#(texpictures[noftexpictures],origin)
+      fi
+    fi
+  else :
+    thelabel@#(txt,origin)
+  fi
+enddef ;
+
+string laboff_   ; laboff_   := ""      ;
+string laboff_c  ; laboff_c  := ""      ;
+string laboff_l  ; laboff_l  := ".lft"  ;
+string laboff_r  ; laboff_r  := ".rt"   ;
+string laboff_b  ; laboff_b  := ".bot"  ;
+string laboff_t  ; laboff_t  := ".top"  ;
+string laboff_lt ; laboff_lt := ".ulft" ;
+string laboff_rt ; laboff_rt := ".urt"  ;
+string laboff_lb ; laboff_lb := ".llft" ;
+string laboff_rb ; laboff_rb := ".lrt"  ;
+string laboff_tl ; laboff_tl := ".ulft" ;
+string laboff_tr ; laboff_tr := ".urt"  ;
+string laboff_bl ; laboff_bl := ".llft" ;
+string laboff_br ; laboff_br := ".lrt"  ;
+
+vardef textextstr(expr s, a) =
+  save ss ; string ss ;
+  ss := "laboff_" & a  ;
+  ss := scantokens ss ;
+  ss := "textext" & ss & "(" & ditto & s & ditto & ")" ;
+  scantokens ss
+enddef ;
+
+pair laboff.origin ; laboff.origin = (infinity,infinity) ;
+pair laboff.raw    ; laboff.raw    = (infinity,infinity) ;
+
+vardef thelabel@#(expr s, z) =
+  save p ; picture p ;
+  p = s if not picture s : infont defaultfont scaled defaultscale fi ;
+  if laboff@#<>laboff.origin :
+    (p shifted (z + labeloffset*laboff@# - (labxf@#*lrcorner p +
+         labyf@#*ulcorner p + (1-labxf@#-labyf@#)*llcorner p)))
+  else :
+    (p shifted z)
+  fi
+enddef;
+
+def build_parshape (expr p, offset_or_path, dx, dy,
+  baselineskip, strutheight, strutdepth, topskip) =
+
+  if unknown trace_parshape :
+    boolean trace_parshape ; trace_parshape := false ;
+  fi ;
+
+  begingroup ;
+
+  save    q, l, r, line, tt, bb,
+          n, hsize, vsize, vvsize, voffset, hoffset, width, indent,
+          ll, lll, rr, rrr, cp, cq, t, b ;
+
+  path    q, l, r, line, tt, bb ;
+  numeric n, hsize, vsize, vvsize, voffset, hoffset, width[], indent[] ;
+  pair    ll, lll, rr, rrr, cp, cq, t, b ;
+
+  n := 0 ; cp := center p ;
+
+  if path offset_or_path :
+    q := offset_or_path ; cq := center q ;
+    voffset := dy ;
+    hoffset := dx ;
+  else :
+    q := p ; cq := center q ;
+    hoffset := offset_or_path + dx ;
+    voffset := offset_or_path + dy ;
+  fi ;
+
+  hsize := xpart lrcorner q - xpart llcorner q ;
+  vsize := ypart urcorner q - ypart lrcorner q ;
+
+  q := p shifted - cp ;
+
+  startsavingdata ;
+
+  savedata "\global\parvoffset " & decimal voffset&"bp " ;
+  savedata "\global\parhoffset " & decimal hoffset&"bp " ;
+  savedata "\global\parwidth   " & decimal   hsize&"bp " ;
+  savedata "\global\parheight  " & decimal   vsize&"bp " ;
+
+  if not path offset_or_path :
+    q := q xscaled ((hsize-2hoffset)/hsize)
+           yscaled ((vsize-2voffset)/vsize) ;
+  fi ;
+
+  hsize := xpart lrcorner q - xpart llcorner q ;
+  vsize := ypart urcorner q - ypart lrcorner q ;
+
+  t := (ulcorner q -- urcorner q) intersection_point q ;
+  b := (llcorner q -- lrcorner q) intersection_point q ;
+
+  if xpart directionpoint t of q < 0 :
+    q := reverse q ;
+  fi ;
+
+  l := q cutbefore t ;
+  l := l if xpart point 0 of q < 0 : & q fi cutafter b ;
+
+  r := q cutbefore b ;
+  r := r if xpart point 0 of q > 0 : & q fi cutafter t ;
+
+%  tt := (ulcorner q -- urcorner q) shifted (0,-topskip) ;
+%  bb := (llcorner q -- lrcorner q) shifted (0,strutdepth) ;
+%
+%  l := l cutbefore (l intersection_point tt) ;
+%  l := l cutafter  (l intersection_point bb) ;
+%  r := r cutbefore (r intersection_point bb) ;
+%  r := r cutafter  (r intersection_point tt) ;
+
+  if trace_parshape :
+    drawarrow p            withpen pencircle scaled 2pt withcolor red ;
+    drawarrow l shifted cp withpen pencircle scaled 1pt withcolor green ;
+    drawarrow r shifted cp withpen pencircle scaled 1pt withcolor blue ;
+  fi ;
+
+  vardef found_point (expr lin, pat, sig) =
+    pair a, b ;
+    a := pat intersection_point (lin shifted (0,strutheight)) ;
+    if intersection_found :
+      a := a shifted (0,-strutheight) ;
+    else :
+      a := pat intersection_point lin ;
+    fi ;
+    b := pat intersection_point (lin shifted (0,-strutdepth)) ;
+    if intersection_found :
+      if sig :
+        if xpart b > xpart a : a := b shifted (0,strutdepth) fi ;
+      else :
+        if xpart b < xpart a : a := b shifted (0,strutdepth) fi ;
+      fi ;
+    fi ;
+    a
+  enddef ;
+
+  if (strutheight+strutdepth<baselineskip) :
+    vvsize := vsize ;
+  else :
+    vvsize := (vsize div baselineskip) * baselineskip ;
+  fi ;
+
+  for i=topskip step baselineskip until vvsize :
+
+    line := (ulcorner q -- urcorner q) shifted (0,-i-eps) ;
+
+    ll := found_point(line,l,true ) ;
+    rr := found_point(line,r,false) ;
+
+    if trace_parshape :
+      fill (ll--rr--rr shifted (0,strutheight)--ll
+        shifted (0,strutheight)--cycle) shifted cp withcolor .5white ;
+      fill (ll--rr--rr shifted (0,-strutdepth)--ll
+        shifted (0,-strutdepth)--cycle) shifted cp withcolor .7white ;
+      draw ll shifted cp withpen pencircle scaled 2pt ;
+      draw rr shifted cp withpen pencircle scaled 2pt ;
+      draw (ll--rr) shifted cp  withpen pencircle scaled .5pt ;
+    fi ;
+
+    n := n + 1 ;
+    indent[n] := abs(xpart ll - xpart llcorner q) ;
+    width[n]  := abs(xpart rr - xpart ll) ;
+
+    if (i=strutheight) and (width[n]<baselineskip) :
+      n := n - 1 ;
+      savedata "\global\chardef\parfirst=1 " ;
+    fi ;
+
+  endfor ;
+
+  savedata "\global\parlines  " & decimal n ;
+  savedata "\global\partoks{  " ;
+  for i=1 upto n:
+    savedata decimal indent[i]&"bp " & decimal width[i]&"bp " ;
+  endfor ;
+  savedata "}" ;
+
+  stopsavingdata ;
+
+  endgroup ;
+
+enddef ;
diff --git a/Master/texmf-dist/metapost/context/base/mp-tool.mp b/Master/texmf-dist/metapost/context/base/mp-tool.mp
new file mode 100644
index 00000000000..925b9ca4449
--- /dev/null
+++ b/Master/texmf-dist/metapost/context/base/mp-tool.mp
@@ -0,0 +1,2366 @@
+%D \module
+%D   [       file=mp-tool.mp,
+%D        version=1998.02.15,
+%D          title=\CONTEXT\ \METAPOST\ graphics,
+%D       subtitle=auxiliary macros,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+% a cleanup is needed, like using image and alike
+% use a few more "newinternal"'s
+
+%D This module is rather preliminary and subjected to
+%D changes.
+
+if known context_tool : endinput ; fi ;
+
+boolean context_tool ; context_tool := true ;
+
+%D New, version number testing:
+%D
+%D \starttyping
+%D fill fullcircle scaled 2cm withcolor if mpversiongt("0.6") : red  else : green fi ;
+%D fill fullcircle scaled 1cm withcolor if mpversionlt(0.6)   : blue else : white fi ;
+%D \stoptyping
+
+if not known mpversion : string mpversion ; mpversion := "0.641" ; fi ;
+
+% vardef mpversiongt(expr s) =
+%     scantokens (mpversion & " > " & if numeric s : decimal s else : s fi)
+% enddef ;
+% vardef mpversionlt(expr s) =
+%     scantokens (mpversion & " < " & if numeric s : decimal s else : s fi)
+% enddef ;
+% vardef mpversioneq(expr s) =
+%     scantokens (mpversion & " = " & if numeric s : decimal s else : s fi)
+% enddef ;
+
+%D More interesting:
+%D
+%D \starttyping
+%D fill fullcircle scaled 4cm withcolor if mpversiongt("0.6")     : red    else : green fi ;
+%D fill fullcircle scaled 2cm withcolor if mpversionlt(0.6)       : blue   else : white fi ;
+%D fill fullcircle scaled 1cm withcolor if mpversioncmp(0.6,">=") : yellow else : black fi ;
+%D \stoptyping
+
+vardef mpversioncmp(expr s, c) =
+    scantokens (mpversion & c & if numeric s : decimal s else : s fi)
+enddef ;
+
+vardef mpversionlt (expr s) = mpversioncmp(s, "<") enddef ;
+vardef mpversioneq (expr s) = mpversioncmp(s, "=") enddef ;
+vardef mpversiongt (expr s) = mpversioncmp(s, ">") enddef ;
+
+%D We always want \EPS\ conforming output, so we say:
+
+prologues    := 2 ; % 1 = troff, 2 = tex
+warningcheck := 0 ;
+
+%D Namespace handling:
+
+% let exclamationmark = ! ;
+% let questionmark    = ? ;
+%
+% def unprotect =
+%   let ! = relax ;
+%   let ? = relax ;
+% enddef ;
+%
+% def protect =
+%   let ! = exclamationmark ;
+%   let ? = questionmark ;
+% enddef ;
+%
+% unprotect ;
+%
+% mp!some!module = 10 ; show mp!some!module ; show somemodule ;
+%
+% protect ;
+
+%D A semicolor to be used in specials: ? ? ?
+
+string semicolor ; semicolor := char 59 ;
+
+%D By including this module, \METAPOST\ automatically writes a
+%D high resolution boundingbox to the \POSTSCRIPT\ file. This
+%D hack is due to John Hobby himself.
+
+% When somehow the first one gets no HiRes, then make sure
+% that the format matches the mem sizes in the config file.
+
+% eerste " " er uit
+
+string space ; space = char 32 ;
+
+vardef ddecimal primary p =
+  decimal xpart p & " " & decimal ypart p
+enddef ;
+
+extra_endfig := extra_endfig
+  & "special "
+       & "("
+       & ditto
+       & "%%HiResBoundingBox: "
+       & ditto
+       & "&ddecimal llcorner currentpicture"
+       & "&space"
+       & "&ddecimal urcorner currentpicture"
+       & ");";
+
+%D Also handy (when we flush colors):
+
+vardef dddecimal primary c =
+  decimal redpart c & " " & decimal greenpart c & " " & decimal bluepart  c
+enddef ;
+
+%D We have standardized data file names:
+
+if not known _data_prefix_ :
+
+  string _data_prefix_ ; _data_prefix_ = "mpd-" ;
+  string _data_suffix_ ; _data_suffix_ = ".tmp" ;
+
+fi ;
+
+def data_file =
+  _data_prefix_ & decimal charcode & _data_suffix_
+enddef ;
+
+%D Because \METAPOST\ has a hard coded limit of 4~datafiles,
+%D we need some trickery when we have multiple files.
+
+if unknown collapse_data :
+  boolean collapse_data ; collapse_data := false ;
+fi ;
+
+boolean savingdata ; savingdata := false ;
+
+def savedata expr txt =
+  if collapse_data :
+    write if savingdata : txt else :
+      "\MPdata{" & decimal charcode & "}{" & txt & "}"
+    fi
+    & "%" to jobname & _data_suffix_ ;
+  else :
+    write txt to data_file ;
+  fi ;
+enddef ;
+
+def startsavingdata =
+  savingdata := true ;
+  if collapse_data :
+    write
+      "\MPdata{" & decimal charcode & "}{%"
+    to
+      jobname & _data_suffix_ ;
+  fi ;
+enddef ;
+
+def stopsavingdata =
+  savingdata := false ;
+  if collapse_data :
+    write "}%" to jobname & _data_suffix_ ;
+  fi ;
+enddef ;
+
+%D Instead of a keystroke eating save and allocation
+%D sequence, you can use the \citeer {new} alternatives to
+%D save and allocate in one command.
+
+def newcolor     text v = forsuffixes i=v : save i ; color     i ; endfor ; enddef ;
+def newnumeric   text v = forsuffixes i=v : save i ; numeric   i ; endfor ; enddef ;
+def newboolean   text v = forsuffixes i=v : save i ; boolean   i ; endfor ; enddef ;
+def newtransform text v = forsuffixes i=v : save i ; transform i ; endfor ; enddef ;
+def newpath      text v = forsuffixes i=v : save i ; path      i ; endfor ; enddef ;
+def newpicture   text v = forsuffixes i=v : save i ; picture   i ; endfor ; enddef ;
+def newstring    text v = forsuffixes i=v : save i ; string    i ; endfor ; enddef ;
+
+%D Sometimes we don't want parts of the graphics add to the
+%D bounding box. One way of doing this is to save the bounding
+%D box, draw the graphics that may not count, and restore the
+%D bounding box.
+%D
+%D \starttypen
+%D push_boundingbox currentpicture;
+%D pop_boundingbox currentpicture;
+%D \stoptypen
+%D
+%D The bounding box can be called with:
+%D
+%D \starttypen
+%D boundingbox currentpicture
+%D inner_boundingbox currentpicture
+%D outer_boundingbox currentpicture
+%D \stoptypen
+%D
+%D Especially the latter one can be of use when we include
+%D the graphic in a document that is clipped to the bounding
+%D box. In such occasions one can use:
+%D
+%D \starttypen
+%D set_outer_boundingbox currentpicture;
+%D \stoptypen
+%D
+%D Its counterpart is:
+%D
+%D \starttypen
+%D set_inner_boundingbox p
+%D \stoptypen
+
+path pushed_boundingbox;
+
+def push_boundingbox text p =
+  pushed_boundingbox := boundingbox p;
+enddef;
+
+def pop_boundingbox text p =
+  setbounds p to pushed_boundingbox;
+enddef;
+
+vardef boundingbox primary p =
+  if (path p) or (picture p) :
+    llcorner p -- lrcorner p -- urcorner p -- ulcorner p
+  else :
+    origin
+  fi -- cycle
+enddef;
+
+vardef inner_boundingbox primary p =
+  top  rt llcorner p --
+  top lft lrcorner p --
+  bot lft urcorner p --
+  bot  rt ulcorner p -- cycle
+enddef;
+
+vardef outer_boundingbox primary p =
+  bot lft llcorner p --
+  bot  rt lrcorner p --
+  top  rt urcorner p --
+  top lft ulcorner p -- cycle
+enddef;
+
+def innerboundingbox = inner_boundingbox enddef ;
+def outerboundingbox = outer_boundingbox enddef ;
+
+vardef set_inner_boundingbox text q =
+  setbounds q to inner_boundingbox q;
+enddef;
+
+vardef set_outer_boundingbox text q =
+  setbounds q to outer_boundingbox q;
+enddef;
+
+%D Some missing functions can be implemented rather
+%D straightforward:
+
+numeric Pi ; Pi := 3.1415926 ;
+
+vardef sqr  primary x = (x*x)                                 enddef ;
+vardef log  primary x = (if x=0: 0 else: mlog(x)/mlog(10) fi) enddef ;
+vardef ln   primary x = (if x=0: 0 else: mlog(x)/256 fi)      enddef ;
+vardef exp  primary x = ((mexp 256)**x)                       enddef ;
+vardef inv  primary x = (if x=0: 0 else: x**-1 fi)            enddef ;
+
+vardef pow (expr x,p) = (x**p)                              enddef ;
+
+vardef asin primary x = (x+(x**3)/6+3(x**5)/40)               enddef ;
+vardef acos primary x = (asin(-x))                            enddef ;
+vardef atan primary x = (x-(x**3)/3+(x**5)/5-(x**7)/7)        enddef ;
+vardef tand primary x = (sind(x)/cosd(x))                     enddef ;
+
+%D Here are Taco Hoekwater's alternatives (but
+%D vardef'd and primaried).
+
+pi := 3.1415926 ; radian := 180/pi ; % 2pi*radian = 360 ;
+
+vardef tand   primary x = (sind(x)/cosd(x))  enddef ;
+vardef cotd   primary x = (cosd(x)/sind(x))  enddef ;
+
+vardef sin    primary x = (sind(x*radian))   enddef ;
+vardef cos    primary x = (cosd(x*radian))   enddef ;
+vardef tan    primary x = (sin(x)/cos(x))    enddef ;
+vardef cot    primary x = (cos(x)/sin(x))    enddef ;
+
+vardef asin   primary x = angle((1+-+x,x))   enddef ;
+vardef acos   primary x = angle((x,1+-+x))   enddef ;
+
+vardef invsin primary x = ((asin(x))/radian) enddef ;
+vardef invcos primary x = ((acos(x))/radian) enddef ;
+
+vardef acosh  primary x = ln(x+(x+-+1))      enddef ;
+vardef asinh  primary x = ln(x+(x++1))       enddef ;
+
+vardef sinh   primary x = save xx ; xx = exp x ; (xx-1/xx)/2 enddef ;
+vardef cosh   primary x = save xx ; xx = exp x ; (xx+1/xx)/2 enddef ;
+
+%D We provide two macros for drawing stripes across a shape.
+%D The first method (with the n suffix) uses another method,
+%D slower in calculation, but more efficient when drawn. The
+%D first macro divides the sides into n equal parts. The
+%D first argument specifies the way the lines are drawn, while
+%D the second argument identifier the way the shape is to be
+%D drawn.
+%D
+%D \starttypen
+%D stripe_path_n
+%D   (dashed evenly withcolor blue)
+%D   (filldraw)
+%D   fullcircle xscaled 100 yscaled 40 shifted (50,50) withpen pencircle scaled 4;
+%D \stoptypen
+%D
+%D The a (or angle) alternative supports arbitrary angles and
+%D is therefore more versatile.
+%D
+%D \starttypen
+%D stripe_path_a
+%D   (withpen pencircle scaled 2 withcolor red)
+%D   (draw)
+%D   fullcircle xscaled 100 yscaled 40 withcolor blue;
+%D \stoptypen
+%D
+%D The first alternative obeys:
+
+stripe_n     := 10;
+stripe_slot  :=  3;
+
+%D When no pen dimensions are passed, the slot determines
+%D the spacing.
+%D
+%D The angle alternative is influenced by:
+
+stripe_gap   :=  5;
+stripe_angle := 45;
+
+def stripe_path_n (text s_spec) (text s_draw) expr s_path =
+  do_stripe_path_n (s_spec) (s_draw) (s_path)
+enddef;
+
+def do_stripe_path_n (text s_spec) (text s_draw) (expr s_path) text s_text =
+  begingroup
+  save curpic, newpic, bb, pp, ww;
+  picture curpic, newpic;
+  path bb, pp;
+  pp := s_path;
+  curpic := currentpicture;
+  currentpicture := nullpicture;
+  s_draw pp s_text;
+  bb := boundingbox currentpicture;
+  newpic := currentpicture;
+  currentpicture := nullpicture;
+  ww := min(ypart urcorner newpic - ypart llcorner newpic,
+            xpart urcorner newpic - xpart llcorner newpic);
+  ww := ww/(stripe_slot*stripe_n);
+  for i=1/stripe_n step 1/stripe_n until 1:
+    draw point (1+i) of bb -- point (3-i) of bb
+      withpen pencircle scaled ww s_spec ;
+  endfor;
+  for i=0 step 1/stripe_n until 1:
+    draw point (3+i) of bb -- point (1-i) of bb
+      withpen pencircle scaled ww s_spec;
+  endfor;
+  clip currentpicture to pp;
+  addto newpic also currentpicture;
+  currentpicture := curpic;
+  addto currentpicture also newpic;
+  endgroup
+enddef;
+
+def stripe_path_a (text s_spec) (text s_draw) expr s_path =
+  do_stripe_path_a (s_spec) (s_draw) (s_path)
+enddef;
+
+def do_stripe_path_a (text s_spec) (text s_draw) (expr s_path) text s_text =
+  begingroup
+  save curpic, newpic, pp; picture curpic, newpic; path pp ;
+  pp := s_path ;
+  curpic := currentpicture;
+  currentpicture := nullpicture;
+  s_draw pp s_text ;
+  def do_stripe_rotation (expr p) =
+    (currentpicture rotatedaround(center p,stripe_angle))
+  enddef ;
+  s_max := max
+   (xpart llcorner do_stripe_rotation(currentpicture),
+    xpart urcorner do_stripe_rotation(currentpicture),
+    ypart llcorner do_stripe_rotation(currentpicture),
+    ypart urcorner do_stripe_rotation(currentpicture));
+  newpic := currentpicture;
+  currentpicture := nullpicture;
+  for i=-s_max-.5stripe_gap step stripe_gap until s_max:
+    draw (-s_max,i)--(s_max,i) s_spec;
+  endfor;
+  currentpicture := do_stripe_rotation(newpic);
+  clip currentpicture to pp ;
+  addto newpic also currentpicture;
+  currentpicture := curpic;
+  addto currentpicture also newpic;
+  endgroup
+enddef;
+
+%D A few normalizing macros:
+%D
+%D \starttypen
+%D xscale_currentpicture  ( width )
+%D yscale_currentpicture  ( height )
+%D xyscale_currentpicture ( width, height )
+%D scale_currentpicture   ( width, height )
+%D \stoptypen
+
+% def xscale_currentpicture(expr the_width) =
+%   natural_width  := xpart urcorner currentpicture - xpart llcorner currentpicture;
+%   currentpicture := currentpicture scaled (the_width/natural_width) ;
+% enddef;
+%
+% def yscale_currentpicture(expr the_height ) =
+%   natural_height := ypart urcorner currentpicture - ypart llcorner currentpicture;
+%   currentpicture := currentpicture scaled (the_height/natural_height) ;
+% enddef;
+%
+% def xyscale_currentpicture(expr the_width, the_height) =
+%   natural_width  := xpart urcorner currentpicture - xpart llcorner currentpicture;
+%   natural_height := ypart urcorner currentpicture - ypart llcorner currentpicture;
+%   currentpicture := currentpicture
+%     xscaled (the_width/natural_width)
+%     yscaled (the_height/natural_height) ;
+% enddef;
+%
+% def scale_currentpicture(expr the_width, the_height) =
+%   xscale_currentpicture(the_width) ;
+%   yscale_currentpicture(the_height) ;
+% enddef;
+
+% nog eens uitbreiden zodat path en pic worden afgehandeld.
+
+%   natural_width  := xpart urcorner currentpicture - xpart llcorner currentpicture;
+%   currentpicture := currentpicture scaled (the_width/natural_width) ;
+
+% TODO TODO TODO TODO, not yet ok
+
+primarydef p xsized w =
+  (p if (bbwidth (p)>0) and (w>0) : scaled (w/bbwidth (p)) fi)
+enddef ;
+
+primarydef p ysized h =
+  (p if (bbheight(p)>0) and (h>0) : scaled (h/bbheight(p)) fi)
+enddef ;
+
+primarydef p xysized s =
+  begingroup ;
+    save wh, w, h ; pair wh ; numeric w, h ;
+    wh := paired (s) ; w := bbwidth(p) ; h := bbheight(p) ;
+    (p if (w>0) and (h>0) :
+         if xpart wh > 0 : xscaled (xpart wh/w) fi
+         if ypart wh > 0 : yscaled (ypart wh/h) fi
+       fi)
+  endgroup
+enddef ;
+
+primarydef p sized wh =
+  (p xysized wh)
+enddef ;
+
+def xscale_currentpicture(expr w) =
+  currentpicture := currentpicture xsized w ;
+enddef;
+
+def yscale_currentpicture(expr h) =
+  currentpicture := currentpicture ysized h ;
+enddef;
+
+def xyscale_currentpicture(expr w, h) =
+  currentpicture := currentpicture xysized (w,h) ;
+enddef;
+
+def scale_currentpicture(expr w, h) =
+  currentpicture := currentpicture xsized w ;
+  currentpicture := currentpicture ysized h ;
+enddef;
+
+%D A full circle is centered at the origin, while a unitsquare
+%D is located in the first quadrant. Now guess what kind of
+%D path fullsquare and unitcircle do return.
+
+path fullsquare, unitcircle ;
+
+fullsquare := unitsquare shifted - center unitsquare ;
+unitcircle := fullcircle shifted urcorner fullcircle ;
+
+%D Some more paths:
+
+path urcircle, ulcircle, llcircle, lrcircle ;
+
+urcircle := origin--(+.5,0)&(+.5,0){up}   ..(0,+.5)&(0,+.5)--cycle ;
+ulcircle := origin--(0,+.5)&(0,+.5){left} ..(-.5,0)&(-.5,0)--cycle ;
+llcircle := origin--(-.5,0)&(-.5,0){down} ..(0,-.5)&(0,-.5)--cycle ;
+lrcircle := origin--(0,-.5)&(0,-.5){right}..(+.5,0)&(+.5,0)--cycle ;
+
+path tcircle, bcircle, lcircle, rcircle ;
+
+tcircle = origin--(+.5,0)&(+.5,0){up}   ..(0,+.5)..{down} (-.5,0)--cycle ;
+bcircle = origin--(-.5,0)&(-.5,0){down} ..(0,-.5)..{up}   (+.5,0)--cycle ;
+lcircle = origin--(0,+.5)&(0,+.5){left} ..(-.5,0)..{right}(0,-.5)--cycle ;
+rcircle = origin--(0,-.5)&(0,-.5){right}..(+.5,0)..{left} (0,+.5)--cycle ;
+
+path urtriangle, ultriangle, lltriangle, lrtriangle ;
+
+urtriangle := origin--(+.5,0)--(0,+.5)--cycle ;
+ultriangle := origin--(0,+.5)--(-.5,0)--cycle ;
+lltriangle := origin--(-.5,0)--(0,-.5)--cycle ;
+lrtriangle := origin--(0,-.5)--(+.5,0)--cycle ;
+
+path unitdiamond, fulldiamond ;
+
+unitdiamond := (.5,0)--(1,.5)--(.5,1)--(0,.5)--cycle ;
+fulldiamond := unitdiamond shifted - center unitdiamond ;
+
+%D More robust:
+
+% let  normalscaled =  scaled ;
+% let normalxscaled = xscaled ;
+% let normalyscaled = yscaled ;
+%
+% def  scaled expr s =  normalscaled (s) enddef ;
+% def xscaled expr s = normalxscaled (s) enddef ;
+% def yscaled expr s = normalyscaled (s) enddef ;
+
+%D Shorter
+
+primarydef p xyscaled q =
+  begingroup ; save qq ; pair qq ; qq = paired(q) ;
+    ( p
+      if xpart qq<>0 : xscaled (xpart qq) fi
+      if ypart qq<>0 : yscaled (ypart qq) fi )
+  endgroup
+enddef ;
+
+%D Experimenteel, zie folder-3.tex.
+
+def set_grid(expr w, h, nx, ny) =
+  boolean grid[][] ; boolean grid_full ;
+  grid_w := w ;
+  grid_h := h ;
+  grid_nx := nx ;
+  grid_ny := ny ;
+  grid_x := round(w/grid_nx) ; % +.5) ;
+  grid_y := round(h/grid_ny) ; % +.5) ;
+  grid_left := (1+grid_x)*(1+grid_y) ;
+  grid_full := false ;
+  for i=0 upto grid_x:
+    for j=0 upto grid_y:
+      grid[i][j] := false ;
+    endfor ;
+  endfor ;
+enddef ;
+
+vardef new_on_grid(expr _dx_, _dy_) =
+  dx := _dx_ ;
+  dy := _dy_ ;
+  ddx := min(round(dx/grid_nx),grid_x) ; % +.5),grid_x) ;
+  ddy := min(round(dy/grid_ny),grid_y) ; % +.5),grid_y) ;
+  if not grid_full and not grid[ddx][ddy]:
+    grid[ddx][ddy] := true ;
+    grid_left := grid_left-1 ;
+    grid_full := (grid_left=0) ;
+    true
+  else:
+    false
+  fi
+enddef ;
+
+%D usage: \type{innerpath peepholed outerpath}.
+%D
+%D beginfig(1);
+%D   def fullsquare = (unitsquare shifted -center unitsquare) enddef ;
+%D   fill (fullsquare scaled 200) withcolor red ;
+%D   path p ; p := (fullcircle scaled 100) ; bboxmargin := 0 ;
+%D   fill p peepholed bbox p ;
+%D endfig;
+
+secondarydef p peepholed q =
+  begingroup ;
+  save start ; pair start ; start := point 0 of p ;
+  if xpart start >= xpart center p :
+    if ypart start >= ypart center p :
+      urcorner q -- ulcorner q -- llcorner q -- lrcorner q --
+      reverse  p -- lrcorner q -- cycle
+    else :
+      lrcorner q -- urcorner q -- ulcorner q -- llcorner q --
+      reverse  p -- llcorner q -- cycle
+    fi
+  else :
+    if ypart start > ypart center p :
+      ulcorner q -- llcorner q -- lrcorner q -- urcorner q --
+      reverse  p -- urcorner q -- cycle
+    else :
+      llcorner q -- lrcorner q -- urcorner q -- ulcorner q --
+      reverse  p -- ulcorner q -- cycle
+    fi
+  fi
+  endgroup
+enddef ;
+
+boolean intersection_found ;
+
+secondarydef p intersection_point q =
+  begingroup
+    save x_, y_ ;
+    (x_,y_) = p intersectiontimes q ;
+    if x_<0 :
+      intersection_found := false ;
+      center p % origin
+    else :
+      intersection_found := true ;
+      .5[point x_ of p, point y_ of q]
+    fi
+  endgroup
+enddef ;
+
+%D New, undocumented, experimental:
+
+vardef tensecircle (expr width, height, offset) =
+  ((-width/2,-height/2) ... (0,-height/2-offset) ...
+   (+width/2,-height/2) ... (+width/2+offset,0) ...
+   (+width/2,+height/2) ... (0,+height/2+offset) ...
+   (-width/2,+height/2) ... (-width/2-offset,0) ... cycle)
+enddef ;
+
+%vardef tensecircle (expr width, height, offset) =
+%  ((-width/2,-height/2)..(0,-height/2-offset)..(+width/2,-height/2) &
+%   (+width/2,-height/2)..(+width/2+offset,0)..(+width/2,+height/2) &
+%   (+width/2,+height/2)..(0,+height/2+offset)..(-width/2,+height/2) &
+%   (-width/2,+height/2)..(-width/2-offset,0)..(-width/2,-height/2)..cycle)
+%enddef ;
+
+vardef roundedsquare (expr width, height, offset) =
+  ((offset,0)--(width-offset,0){right}          ..
+   (width,offset)--(width,height-offset){up}    ..
+   (width-offset,height)--(offset,height){left} ..
+   (0,height-offset)--(0,offset){down}          .. cycle)
+enddef ;
+
+%D Some colors.
+
+color cyan    ; cyan    = (0,1,1) ;
+color magenta ; magenta = (1,0,1) ;
+color yellow  ; yellow  = (1,1,0) ;
+
+%D Well, this is the dangerous and naive version:
+
+def drawfill text t =
+  fill t ;
+  draw t ;
+enddef;
+
+%D This two step approach saves the path first, since it can
+%D be a function. Attributes must not be randomized.
+
+def drawfill expr c =
+  path _c_ ; _c_ := c ;
+  do_drawfill
+enddef ;
+
+def do_drawfill text t =
+  draw _c_ t ;
+  fill _c_ t ;
+enddef;
+
+def undrawfill expr c =
+  drawfill c withcolor background
+enddef ;
+
+%D Moved from mp-char.mp
+
+vardef paired (expr d) =
+  if pair d : d else : (d,d) fi
+enddef ;
+
+vardef tripled (expr d) =
+  if color d : d else : (d,d,d) fi
+enddef ;
+
+primarydef p enlarged d =
+  (p llmoved d -- p lrmoved d -- p urmoved d -- p ulmoved d -- cycle)
+enddef;
+
+primarydef p llenlarged d =
+  (p llmoved d -- lrcorner p -- urcorner p -- ulcorner p -- cycle)
+enddef ;
+
+primarydef p lrenlarged d =
+  (llcorner p -- p lrmoved d -- urcorner p -- ulcorner p -- cycle)
+enddef ;
+
+primarydef p urenlarged d =
+  (llcorner p -- lrcorner p -- p urmoved d -- ulcorner p -- cycle)
+enddef ;
+
+primarydef p ulenlarged d =
+  (llcorner p -- lrcorner p -- urcorner p -- p ulmoved d -- cycle)
+enddef ;
+
+primarydef p llmoved d =
+  ((llcorner p) shifted (-xpart paired(d),-ypart paired(d)))
+enddef ;
+
+primarydef p lrmoved d =
+  ((lrcorner p) shifted (+xpart paired(d),-ypart paired(d)))
+enddef ;
+
+primarydef p urmoved d =
+  ((urcorner p) shifted (+xpart paired(d),+ypart paired(d)))
+enddef ;
+
+primarydef p ulmoved d =
+  ((ulcorner p) shifted (-xpart paired(d),+ypart paired(d)))
+enddef ;
+
+primarydef p leftenlarged d =
+  ((llcorner p) shifted (-d,0) -- lrcorner p --
+   urcorner p -- (ulcorner p) shifted (-d,0) -- cycle)
+enddef ;
+
+primarydef p rightenlarged d =
+  (llcorner p -- (lrcorner p) shifted (d,0) --
+   (urcorner p) shifted (d,0) -- ulcorner p -- cycle)
+enddef ;
+
+primarydef p topenlarged d =
+  (llcorner p -- lrcorner p --
+   (urcorner p) shifted (0,d) -- (ulcorner p) shifted (0,d) -- cycle)
+enddef ;
+
+primarydef p bottomenlarged d =
+  (llcorner p shifted (0,-d) -- lrcorner p shifted (0,-d) --
+   urcorner p -- ulcorner p -- cycle)
+enddef ;
+
+%D Handy for testing/debugging:
+
+primarydef p crossed d =
+  (center p shifted (-d, 0) -- llcorner p --
+   center p shifted ( 0,-d) -- lrcorner p --
+   center p shifted (+d, 0) -- urcorner p --
+   center p shifted ( 0,+d) -- ulcorner p -- cycle)
+enddef ;
+
+%D Saves typing:
+
+% vardef bottomboundary primary p = (llcorner p -- lrcorner p) enddef ;
+% vardef rightboundary  primary p = (lrcorner p -- urcorner p) enddef ;
+% vardef topboundary    primary p = (urcorner p -- ulcorner p) enddef ;
+% vardef leftboundary   primary p = (ulcorner p -- llcorner p) enddef ;
+
+vardef bottomboundary primary p =
+  if pair p : p else : (llcorner p -- lrcorner p) fi
+enddef ;
+
+vardef rightboundary  primary p =
+  if pair p : p else : (lrcorner p -- urcorner p) fi
+enddef ;
+
+vardef topboundary    primary p =
+  if pair p : p else : (urcorner p -- ulcorner p) fi
+enddef ;
+
+vardef leftboundary   primary p =
+  if pair p : p else : (ulcorner p -- llcorner p) fi
+enddef ;
+
+%D Nice too:
+
+primarydef p superellipsed s =
+  superellipse
+   (.5[lrcorner p,urcorner p],
+    .5[urcorner p,ulcorner p],
+    .5[ulcorner p,llcorner p],
+    .5[llcorner p,lrcorner p],
+    s)
+enddef ;
+
+primarydef p squeezed s =
+  ((llcorner p .. .5[llcorner p,lrcorner p] shifted ( 0, ypart paired(s)) .. lrcorner p) &
+   (lrcorner p .. .5[lrcorner p,urcorner p] shifted (-xpart paired(s), 0) .. urcorner p) &
+   (urcorner p .. .5[urcorner p,ulcorner p] shifted ( 0,-ypart paired(s)) .. ulcorner p) &
+   (ulcorner p .. .5[ulcorner p,llcorner p] shifted ( xpart paired(s), 0) .. llcorner p) & cycle)
+enddef ;
+
+primarydef p randomshifted s =
+  begingroup ; save ss ; pair ss ; ss := paired(s) ;
+  p shifted (-.5xpart ss + uniformdeviate xpart ss,
+             -.5ypart ss + uniformdeviate ypart ss)
+  endgroup
+enddef ;
+
+%primarydef p randomized s =
+%  for i=0 upto length(p)-1 :
+%   ((point       i    of p) randomshifted s) .. controls
+%   ((postcontrol i    of p) randomshifted s) and
+%   ((precontrol (i+1) of p) randomshifted s) ..
+%  endfor cycle
+%enddef ;
+
+primarydef p randomized s =
+  (if path p :
+    for i=0 upto length(p)-1 :
+      ((point       i    of p) randomshifted s) .. controls
+      ((postcontrol i    of p) randomshifted s) and
+      ((precontrol (i+1) of p) randomshifted s) ..
+    endfor
+    if cycle p :
+      cycle
+    else :
+      ((point length(p) of p) randomshifted s)
+    fi
+  elseif pair p :
+    p randomshifted s
+  elseif color p :
+    if color s :
+      (uniformdeviate redpart   s * redpart   p,
+       uniformdeviate greenpart s * greenpart p,
+       uniformdeviate bluepart  s * bluepart  p)
+    elseif pair s :
+      ((xpart s + uniformdeviate (ypart s - xpart s)) * p)
+    else :
+      (uniformdeviate s * p)
+    fi
+  else :
+    p + uniformdeviate s
+  fi)
+enddef ;
+
+%D Not perfect (alternative for interpath)
+
+vardef interpolated(expr s, p, q) =
+  save m ; m := max(length(p),length(q)) ;
+  (if path p :
+     for i=0 upto m-1 :
+       s[point       (i   /m) along p,
+         point       (i   /m) along q] .. controls
+       s[postcontrol (i   /m) along p,
+         postcontrol (i   /m) along q] and
+       s[precontrol ((i+1)/m) along p,
+         precontrol ((i+1)/m) along q] ..
+     endfor
+     if cycle p :
+       cycle
+     else :
+       s[point infinity of p,
+         point infinity of q]
+     fi
+   else :
+     a[p,q]
+   fi)
+enddef ;
+
+%D Interesting too:
+
+% primarydef p parallel s =
+%   begingroup ; save q, b ; path q ; numeric b ;
+%   b := xpart (lrcorner p - llcorner p) ;
+%   q := p if b>0 : scaled ((b+2s)/b) fi ;
+%   (q shifted (center p-center q))
+%   endgroup
+% enddef ;
+
+%primarydef p parallel s =
+%  begingroup ; save q, w,h ; path q ; numeric w, h ;
+%  w := bbwidth(p) ; h := bbheight(p) ;
+%  q := p if (w>0) and (h>0) :
+%    xyscaled ((w+2*xpart paired(s))/w,(h+2*ypart paired(s))/h) fi ;
+%  (q shifted (center p-center q))
+%  endgroup
+%enddef ;
+
+vardef punked primary p =
+  (point 0 of p for i=1 upto length(p)-1 : -- point i of p endfor
+   if cycle p : -- cycle else : -- point length(p) of p fi)
+enddef ;
+
+vardef curved primary p =
+  (point 0 of p for i=1 upto length(p)-1 : .. point i of p endfor
+   if cycle p : .. cycle else : .. point length(p) of p fi)
+enddef ;
+
+primarydef p blownup s =
+  begingroup
+    save _p_ ; path _p_ ; _p_ := p xysized
+     (bbwidth (p)+2(xpart paired(s)),
+      bbheight(p)+2(ypart paired(s))) ;
+    (_p_ shifted (center p - center _p_))
+  endgroup
+enddef ;
+
+%D Rather fundamental.
+
+% vardef rightpath expr p =
+%   save q, t, b ; path q ; pair t, b ;
+%   t := (ulcorner p -- urcorner p) intersection_point p ;
+%   b := (llcorner p -- lrcorner p) intersection_point p ;
+%   if xpart directionpoint t of p < 0 : p := reverse p ; fi ;
+%   q := p cutbefore b ;
+%   q := q if xpart point 0 of p > 0 : & p fi cutafter t ;
+%   q
+% enddef ;
+%
+% vardef leftpath expr p =
+%   save q, t, b ; path q ; pair t, b ;
+%   t := (ulcorner p -- urcorner p) intersection_point p ;
+%   b := (llcorner p -- lrcorner p) intersection_point p ;
+%   if xpart directionpoint t of p < 0 : p := reverse p ; fi ;
+%   q := p cutbefore t ;
+%   q := q if xpart point 0 of p > 0 : & p fi cutafter b ;
+%   q
+% enddef ;
+
+def leftrightpath(expr p, l) =
+  save q, t, b ; path q ; pair t, b ;
+  t := (ulcorner p -- urcorner p) intersection_point p ;
+  b := (llcorner p -- lrcorner p) intersection_point p ;
+  if xpart directionpoint t of p < 0 : p := reverse p ; fi ;
+  q := p    cutbefore if l: t else: b fi ;
+  q := q if xpart point 0 of p > 0 : &
+       p fi cutafter  if l: b else: t fi ;
+  q
+enddef ;
+
+vardef  leftpath expr p = leftrightpath(p,true ) enddef ;
+vardef rightpath expr p = leftrightpath(p,false) enddef ;
+
+%D Drawoptions
+
+def saveoptions =
+  save _op_ ; def _op_ = enddef ;
+enddef ;
+
+%D Tracing.
+
+let normaldraw = draw ;
+let normalfill = fill ;
+
+def drawlineoptions   (text t) = def _lin_opt_ = t enddef ; enddef ;
+def drawpointoptions  (text t) = def _pnt_opt_ = t enddef ; enddef ;
+def drawcontroloptions(text t) = def _ctr_opt_ = t enddef ; enddef ;
+def drawlabeloptions  (text t) = def _lab_opt_ = t enddef ; enddef ;
+def draworiginoptions (text t) = def _ori_opt_ = t enddef ; enddef ;
+def drawboundoptions  (text t) = def _bnd_opt_ = t enddef ; enddef ;
+def drawpathoptions   (text t) = def _pth_opt_ = t enddef ; enddef ;
+
+def resetdrawoptions =
+  drawlineoptions   (withpen pencircle scaled 1pt   withcolor .5white) ;
+  drawpointoptions  (withpen pencircle scaled 4pt   withcolor   black) ;
+  drawcontroloptions(withpen pencircle scaled 2.5pt withcolor   black) ;
+  drawlabeloptions  () ;
+  draworiginoptions (withpen pencircle scaled 1pt   withcolor .5white) ;
+  drawboundoptions  (dashed evenly _ori_opt_) ;
+  drawpathoptions   (withpen pencircle scaled 5pt   withcolor .8white) ;
+enddef ;
+
+resetdrawoptions ;
+
+%D Path.
+
+def drawpath expr p =
+  normaldraw p _pth_opt_
+enddef ;
+
+%D Arrow.
+
+vardef drawarrowpath expr p =
+  save autoarrows ; boolean autoarrows ; autoarrows := true ;
+  drawarrow p _pth_opt_
+enddef ;
+
+%def drawarrowpath expr p =
+%  begingroup ;
+%  save autoarrows ; boolean autoarrows ; autoarrows := true ;
+%  save arrowpath ; path arrowpath ; arrowpath := p ;
+%  _drawarrowpath_
+%enddef ;
+%
+%def _drawarrowpath_ text t =
+%  drawarrow arrowpath _pth_opt_ t ;
+%  endgroup ;
+%enddef ;
+
+def midarrowhead expr p =
+  arrowhead p cutafter
+    (point length(p cutafter point .5 along p)+ahlength on p)
+enddef ;
+
+vardef arrowheadonpath (expr p, s) =
+  save autoarrows ; boolean autoarrows ; autoarrows := true ;
+  arrowhead p if s<1 : cutafter (point (s*arclength(p)+.5ahlength) on p) fi
+enddef ;
+
+%D Points.
+
+def drawpoint expr c =
+  if string c :
+    string _c_ ; _c_ := "(" & c & ")" ;
+    dotlabel.urt(_c_, scantokens _c_) ;
+    drawdot scantokens _c_
+  else :
+    dotlabel.urt("(" & decimal xpart c & "," & decimal ypart c & ")", c) ;
+    drawdot c
+  fi _pnt_opt_
+enddef ;
+
+%D PathPoints.
+
+def drawpoints        expr c = path _c_ ; _c_ := c ; do_drawpoints        enddef ;
+def drawcontrolpoints expr c = path _c_ ; _c_ := c ; do_drawcontrolpoints enddef ;
+def drawcontrollines  expr c = path _c_ ; _c_ := c ; do_drawcontrollines  enddef ;
+def drawpointlabels   expr c = path _c_ ; _c_ := c ; do_drawpointlabels   enddef ;
+
+def do_drawpoints text t =
+  for _i_=0 upto length(_c_) :
+    normaldraw point _i_ of _c_ _pnt_opt_ t ;
+  endfor ;
+enddef;
+
+def do_drawcontrolpoints text t =
+  for _i_=0 upto length(_c_) :
+    normaldraw precontrol  _i_ of _c_ _ctr_opt_ t ;
+    normaldraw postcontrol _i_ of _c_ _ctr_opt_ t ;
+  endfor ;
+enddef;
+
+def do_drawcontrollines text t =
+  for _i_=0 upto length(_c_) :
+    normaldraw point _i_ of _c_ -- precontrol  _i_ of _c_ _lin_opt_ t ;
+    normaldraw point _i_ of _c_ -- postcontrol _i_ of _c_ _lin_opt_ t ;
+  endfor ;
+enddef;
+
+boolean swappointlabels ; swappointlabels := false ;
+
+def do_drawpointlabels text t =
+  for _i_=0 upto length(_c_) :
+    pair _u_ ; _u_ := unitvector(direction _i_ of _c_)
+      rotated if swappointlabels : - fi 90 ;
+    pair _p_ ; _p_ := (point _i_ of _c_) ;
+    _u_ := 12 * defaultscale * _u_ ;
+    normaldraw thelabel ( decimal _i_,
+    _p_ shifted if cycle _c_ and (_i_=0) : - fi _u_ ) _lab_opt_ t ;
+  endfor ;
+enddef;
+
+%D Bounding box.
+
+def drawboundingbox expr p =
+  normaldraw boundingbox p _bnd_opt_
+enddef ;
+
+%D Origin.
+
+numeric originlength ; originlength := .5cm ;
+
+def draworigin text t =
+  normaldraw (origin shifted (0, originlength) --
+              origin shifted (0,-originlength)) _ori_opt_ t ;
+  normaldraw (origin shifted ( originlength,0) --
+              origin shifted (-originlength,0)) _ori_opt_ t ;
+enddef;
+
+%D Axis.
+
+numeric tickstep   ; tickstep   := 5mm ;
+numeric ticklength ; ticklength := 2mm ;
+
+def drawxticks expr c = path _c_ ; _c_ := c ; do_drawxticks enddef ;
+def drawyticks expr c = path _c_ ; _c_ := c ; do_drawyticks enddef ;
+def drawticks  expr c = path _c_ ; _c_ := c ; do_drawticks  enddef ;
+
+% Adding eps prevents disappearance due to rounding errors.
+
+def do_drawxticks text t =
+  for i=0 step -tickstep until xpart llcorner _c_ - eps :
+    if (i<=xpart lrcorner _c_) :
+      normaldraw (i,-ticklength)--(i,ticklength) _ori_opt_ t ;
+    fi ;
+  endfor ;
+  for i=0 step  tickstep until xpart lrcorner _c_ + eps :
+    if (i>=xpart llcorner _c_) :
+      normaldraw (i,-ticklength)--(i,ticklength) _ori_opt_ t ;
+    fi ;
+  endfor ;
+  normaldraw (llcorner _c_ -- ulcorner _c_)
+    shifted (-xpart llcorner _c_,0) _ori_opt_ t ;
+enddef ;
+
+def do_drawyticks text t =
+  for i=0 step -tickstep until ypart llcorner _c_ - eps :
+    if (i<=ypart ulcorner _c_) :
+      normaldraw (-ticklength,i)--(ticklength,i) _ori_opt_ t ;
+    fi ;
+  endfor ;
+  for i=0 step  tickstep until ypart ulcorner _c_ + eps :
+    if (i>=ypart llcorner _c_) :
+      normaldraw (-ticklength,i)--(ticklength,i) _ori_opt_ t ;
+    fi ;
+  endfor ;
+  normaldraw (llcorner _c_ -- lrcorner _c_)
+    shifted (0,-ypart llcorner _c_) _ori_opt_ t ;
+enddef ;
+
+def do_drawticks text t =
+  drawxticks _c_ t ;
+  drawyticks _c_ t ;
+enddef ;
+
+%D All of it except axis.
+
+def drawwholepath expr p =
+  draworigin          ;
+  drawpath          p ;
+  drawcontrollines  p ;
+  drawcontrolpoints p ;
+  drawpoints        p ;
+  drawboundingbox   p ;
+  drawpointlabels   p ;
+enddef ;
+
+%D Tracing.
+
+def visualizeddraw expr c =
+  if picture c : normaldraw c else : path _c_ ; _c_ := c ; do_visualizeddraw fi
+enddef ;
+
+def visualizedfill expr c =
+  if picture c : normalfill c else : path _c_ ; _c_ := c ; do_visualizedfill fi
+enddef ;
+
+def do_visualizeddraw text t =
+  draworigin              ;
+  drawpath          _c_ t ;
+  drawcontrollines  _c_ ;
+  drawcontrolpoints _c_ ;
+  drawpoints        _c_ ;
+  drawboundingbox   _c_ ;
+  drawpointlabels   _c_ ;
+enddef ;
+
+def do_visualizedfill text t =
+  if cycle _c_ : normalfill _c_ t fi ;
+  draworigin            ;
+  drawcontrollines  _c_ ;
+  drawcontrolpoints _c_ ;
+  drawpoints        _c_ ;
+  drawboundingbox   _c_ ;
+  drawpointlabels   _c_ ;
+enddef ;
+
+def visualizepaths =
+  let fill = visualizedfill ;
+  let draw = visualizeddraw ;
+enddef ;
+
+def naturalizepaths =
+  let fill = normalfill ;
+  let draw = normaldraw ;
+enddef ;
+
+extra_endfig := extra_endfig & " naturalizepaths ; " ;
+
+%D Normally, arrowheads don't scale well. So we provide a
+%D hack.
+
+boolean autoarrows ; autoarrows := false ;
+numeric ahfactor   ; ahfactor   := 2.5 ;
+
+def set_ahlength (text t) =
+  ahlength := (ahfactor*pen_size(_op_ t)) ; % _op_ added
+enddef ;
+
+vardef pen_size (text t) =
+  save p ; picture p ; p := nullpicture ;
+  addto p doublepath (top origin -- bot origin) t ;
+  (ypart urcorner p - ypart lrcorner p)
+enddef ;
+
+%D The next two macros are adapted versions of plain
+%D \METAPOST\ definitions.
+
+def _finarr text t =
+  if autoarrows : set_ahlength (t) fi ;
+  draw               _apth t ;
+  filldraw arrowhead _apth t ;
+enddef;
+
+def _findarr text t =
+  if autoarrows : set_ahlength (t) fi ;
+  draw                   _apth                    t ;
+  fill arrowhead         _apth withpen currentpen t ;
+  fill arrowhead reverse _apth withpen currentpen t ;
+enddef ;
+
+%D Handy too ......
+
+vardef pointarrow (expr pat, loc, len, off) =
+  save l, r, s, t ; path l, r ; numeric s ; pair t ;
+  t := if pair loc : loc else : point loc along pat fi ;
+% draw t withpen pencircle scaled 10 withcolor .5white ;
+  s := len/2 - off ; if s<=0 : s := 0 elseif s>len : s := len fi ;
+  r := pat cutbefore t ;
+  r := (r cutafter point (arctime s of r) of r) ;
+  s := len/2 + off ; if s<=0 : s := 0 elseif s>len : s := len fi ;
+  l := reverse (pat cutafter t) ;
+  l := (reverse (l cutafter point (arctime s of l) of l)) ;
+  (l..r)
+enddef ;
+
+def rightarrow  (expr pat,tim,len) = pointarrow(pat,tim,len,-len) enddef ;
+def leftarrow   (expr pat,tim,len) = pointarrow(pat,tim,len,+len) enddef ;
+def centerarrow (expr pat,tim,len) = pointarrow(pat,tim,len,   0) enddef ;
+
+%D The \type {along} and \type {on} operators can be used
+%D as follows:
+%D
+%D \starttypen
+%D drawdot point .5  along somepath ;
+%D drawdot point 3cm on    somepath ;
+%D \stoptypen
+%D
+%D The number denotes a percentage (fraction).
+
+primarydef pct along pat = % also negative
+  (arctime (pct * (arclength pat)) of pat) of pat
+enddef ;
+
+% primarydef len on pat =
+%   (arctime len of pat) of pat
+% enddef ;
+
+primarydef len on pat =
+  (arctime if len>0 : len else : (arclength(pat)+len) fi of pat) of pat
+enddef ;
+
+% this cuts of a piece from both ends
+
+% tertiarydef pat cutends len =
+%   begingroup ; save tap ; path tap ;
+%   tap := pat cutbefore (point len on pat) ;
+%   (tap cutafter (point -len on tap))
+%   endgroup
+% enddef ;
+
+tertiarydef pat cutends len =
+  begingroup ; save tap ; path tap ;
+  tap := pat cutbefore (point (xpart paired(len)) on pat) ;
+  (tap cutafter (point -(ypart paired(len)) on tap))
+  endgroup
+enddef ;
+
+%D To be documented.
+
+path freesquare ;
+
+freesquare := ((-1,0)--(-1,-1)--(0,-1)--(+1,-1)--
+               (+1,0)--(+1,+1)--(0,+1)--(-1,+1)--cycle) scaled .5 ;
+
+numeric freelabeloffset  ; freelabeloffset  := 3pt ;
+numeric freedotlabelsize ; freedotlabelsize := 3pt ;
+
+vardef thefreelabel (expr str, loc, ori) =
+  save s, p, q, l ; picture s ; path p, q ; pair l ;
+  interim labeloffset := freelabeloffset ;
+  s := if string str : thelabel(str,loc) else : str shifted -center str shifted loc fi ;
+  setbounds s to boundingbox s enlarged freelabeloffset ;
+  p := fullcircle scaled (2*length(loc-ori)) shifted ori ;
+  q := freesquare xyscaled (urcorner s - llcorner s) ;
+%  l := point (xpart (p intersectiontimes (ori--loc))) of q ;
+  l := point xpart (p intersectiontimes
+   (ori--((1+eps)*arclength(ori--loc)*unitvector(loc-ori)))) of q ;
+  setbounds s to boundingbox s enlarged -freelabeloffset ; % new
+ %draw boundingbox s shifted -l withpen pencircle scaled .5pt withcolor red ;
+  (s shifted -l)
+enddef ;
+
+% better?
+
+vardef thefreelabel (expr str, loc, ori) =
+  save s, p, q, l ; picture s ; path p, q ; pair l ;
+  interim labeloffset := freelabeloffset ;
+  s := if string str : thelabel(str,loc) else : str shifted -center str shifted loc fi ;
+  setbounds s to boundingbox s enlarged freelabeloffset ;
+  p := fullcircle scaled (2*length(loc-ori)) shifted ori ;
+  q := freesquare xyscaled (urcorner s - llcorner s) ;
+  l := point xpart (p intersectiontimes (ori--loc shifted (loc-ori))) of q ;
+  setbounds s to boundingbox s enlarged -freelabeloffset ; % new
+ %draw boundingbox s shifted -l withpen pencircle scaled .5pt withcolor red ;
+  (s shifted -l)
+enddef ;
+
+vardef freelabel (expr str, loc, ori) =
+  draw thefreelabel(str,loc,ori) ;
+enddef ;
+
+vardef freedotlabel (expr str, loc, ori) =
+  interim linecap:=rounded ;
+  draw loc withpen pencircle scaled freedotlabelsize ;
+  draw thefreelabel(str,loc,ori) ;
+enddef ;
+
+%D \starttypen
+%D drawarrow anglebetween(line_a,line_b,somelabel) ;
+%D \stoptypen
+
+%       angleoffset ; angleoffset :=  0pt ;
+numeric anglelength ; anglelength := 20pt ;
+numeric anglemethod ; anglemethod :=    1 ;
+
+% vardef anglebetween (expr a, b, str) = % path path string
+%   save pointa, pointb, common, middle, offset ;
+%   pair pointa, pointb, common, middle, offset ;
+%   save curve ; path curve ;
+%   save where ; numeric where ;
+%   if round point 0 of a = round point 0 of b :
+%     common := point 0 of a ;
+%   else :
+%     common := a intersectionpoint b ;
+%   fi ;
+%   pointa := point anglelength on a ;
+%   pointb := point anglelength on b ;
+%   where  := turningnumber (common--pointa--pointb--cycle) ;
+%   middle := ((common--pointa) rotatedaround (pointa,-where*90))
+%                             intersectionpoint
+%             ((common--pointb) rotatedaround (pointb, where*90)) ;
+%   if     anglemethod = 0 :
+%     curve  := pointa{unitvector(middle-pointa)}.. pointb;
+%     middle := point .5 along curve ;
+%     curve  := common ;
+%   elseif anglemethod = 1 :
+%     curve  := pointa{unitvector(middle-pointa)}.. pointb;
+%     middle := point .5 along curve ;
+%   elseif anglemethod = 2 :
+%     middle := common rotatedaround(.5[pointa,pointb],180) ;
+%     curve  := pointa--middle--pointb ;
+%   elseif anglemethod = 3 :
+%     curve  := pointa--middle--pointb ;
+%   elseif anglemethod = 4 :
+%     curve  := pointa..controls middle..pointb ;
+%     middle := point .5 along curve ;
+%   fi ;
+%   draw thefreelabel(str, middle, common) withcolor black ;
+%   curve
+% enddef ;
+
+vardef anglebetween (expr a, b, str) = % path path string
+  save pointa, pointb, common, middle, offset ;
+  pair pointa, pointb, common, middle, offset ;
+  save curve ; path curve ;
+  save where ; numeric where ;
+  if round point 0 of a = round point 0 of b :
+    common := point 0 of a ;
+  else :
+    common := a intersectionpoint b ;
+  fi ;
+  pointa := point anglelength on a ;
+  pointb := point anglelength on b ;
+  where  := turningnumber (common--pointa--pointb--cycle) ;
+  middle := (reverse(common--pointa) rotatedaround (pointa,-where*90))
+                            intersection_point
+            (reverse(common--pointb) rotatedaround (pointb, where*90)) ;
+  if not intersection_found :
+    middle := point .5 along
+      ((reverse(common--pointa) rotatedaround (pointa,-where*90)) --
+       (       (common--pointb) rotatedaround (pointb, where*90))) ;
+  fi ;
+  if     anglemethod = 0 :
+    curve  := pointa{unitvector(middle-pointa)}.. pointb;
+    middle := point .5 along curve ;
+    curve  := common ;
+  elseif anglemethod = 1 :
+    curve  := pointa{unitvector(middle-pointa)}.. pointb;
+    middle := point .5 along curve ;
+  elseif anglemethod = 2 :
+    middle := common rotatedaround(.5[pointa,pointb],180) ;
+    curve  := pointa--middle--pointb ;
+  elseif anglemethod = 3 :
+    curve  := pointa--middle--pointb ;
+  elseif anglemethod = 4 :
+    curve  := pointa..controls middle..pointb ;
+    middle := point .5 along curve ;
+  fi ;
+  draw thefreelabel(str, middle, common) ; % withcolor black ;
+  curve
+enddef ;
+
+% Stack
+
+picture currentpicturestack[] ;
+numeric currentpicturedepth ; currentpicturedepth := 0 ;
+
+def pushcurrentpicture =
+  currentpicturedepth := currentpicturedepth + 1 ;
+  currentpicturestack[currentpicturedepth] := currentpicture ;
+  currentpicture := nullpicture ;
+enddef ;
+
+def popcurrentpicture text t = % optional text
+  if currentpicturedepth > 0 :
+    addto currentpicturestack[currentpicturedepth] also currentpicture t ;
+    currentpicture := currentpicturestack[currentpicturedepth] ;
+    currentpicturedepth := currentpicturedepth - 1 ;
+  fi ;
+enddef ;
+
+%D colorcircle(size, red, green, blue) ;
+
+% vardef colorcircle (expr size, red, green, blue) =
+%   save r, g, b, rr, gg, bb, cc, mm, yy ; save radius ;
+%   path r, g, b, rr, bb, gg, cc, mm, yy ; numeric radius ;
+%
+%   radius := 5cm ; pickup pencircle scaled (radius/25) ;
+%
+%   r := g := b := fullcircle scaled radius shifted (0,radius/4) ;
+%
+%   r := r rotatedaround (origin, 15) ;
+%   g := g rotatedaround (origin,135) ;
+%   b := b rotatedaround (origin,255) ;
+%
+%   r := r rotatedaround(center r,-90) ;
+%   g := g rotatedaround(center g, 90) ;
+%
+%   gg := buildcycle(buildcycle(reverse r,b),g) ;
+%   cc := buildcycle(buildcycle(b,reverse g),r) ;
+%
+%   rr := gg rotatedaround(origin,120) ;
+%   bb := gg rotatedaround(origin,240) ;
+%
+%   yy := cc rotatedaround(origin,120) ;
+%   mm := cc rotatedaround(origin,240) ;
+%
+%   pushcurrentpicture ;
+%
+%   fill fullcircle scaled radius withcolor white ;
+%
+%   fill rr withcolor red   ; fill cc withcolor white-red   ;
+%   fill gg withcolor green ; fill mm withcolor white-green ;
+%   fill bb withcolor blue  ; fill yy withcolor white-blue  ;
+%
+%   for i = rr,gg,bb,cc,mm,yy : draw i withcolor .5white ; endfor ;
+%
+%   currentpicture := currentpicture xsized size ;
+%
+%   popcurrentpicture ;
+% enddef ;
+
+% vardef colorcircle (expr size, red, green, blue) =
+%   save r, g, b, rr, gg, bb, cc, mm, yy ; save radius ;
+%   path r, g, b, rr, bb, gg, cc, mm, yy ; numeric radius ;
+%
+%   radius := 5cm ; pickup pencircle scaled (radius/25) ;
+%
+%   transform t ; t := identity rotatedaround(origin,120) ;
+%
+%   r := fullcircle scaled radius
+%    shifted (0,radius/4) rotatedaround(origin,15) ;
+%
+%   g := r transformed t ; b := g transformed t ;
+%
+%   r := r rotatedaround(center r,-90) ;
+%   g := g rotatedaround(center g, 90) ;
+%
+%   gg := buildcycle(buildcycle(reverse r,b),g) ;
+%   cc := buildcycle(buildcycle(b,reverse g),r) ;
+%
+%   rr := gg transformed t ; bb := rr transformed t ;
+%   yy := cc transformed t ; mm := yy transformed t ;
+%
+%   pushcurrentpicture ;
+%
+%   fill fullcircle scaled radius withcolor white ;
+%
+%   fill rr withcolor red   ; fill cc withcolor white-red   ;
+%   fill gg withcolor green ; fill mm withcolor white-green ;
+%   fill bb withcolor blue  ; fill yy withcolor white-blue  ;
+%
+%   for i = rr,gg,bb,cc,mm,yy : draw i withcolor .5white ; endfor ;
+%
+%   currentpicture := currentpicture xsized size ;
+%
+%   popcurrentpicture ;
+% enddef ;
+
+vardef colorcircle (expr size, red, green, blue) =
+  save r, g, b, c, m, y, w ; save radius ;
+  path r, g, b, c, m, y, w ; numeric radius ;
+
+  radius := 5cm ; pickup pencircle scaled (radius/25) ;
+
+  transform t ; t := identity rotatedaround(origin,120) ;
+
+  r := fullcircle rotated 90 scaled radius
+         shifted (0,radius/4) rotatedaround(origin,135) ;
+
+  b := r transformed t ; g := b transformed t ;
+
+  c := buildcycle(subpath(1,7) of g,subpath(1,7) of b) ;
+  y := c transformed t ; m := y transformed t ;
+
+  w := buildcycle(subpath(3,5) of r, subpath(3,5) of g,subpath(3,5) of b) ;
+
+  pushcurrentpicture ;
+
+  fill r withcolor       red   ;
+  fill g withcolor       green ;
+  fill b withcolor       blue  ;
+  fill c withcolor white-red   ;
+  fill m withcolor white-green ;
+  fill y withcolor white-blue  ;
+  fill w withcolor white       ;
+
+  for i = r,g,b,c,m,y : draw i withcolor .5white ; endfor ;
+
+  currentpicture := currentpicture xsized size ;
+
+  popcurrentpicture ;
+enddef ;
+
+% penpoint (i,2) of somepath -> inner / outer point
+
+vardef penpoint expr pnt of p =
+  save n, d ; numeric n, d ;
+  (n,d) = if pair pnt : pnt else : (pnt,1) fi ;
+  (point n of p shifted ((penoffset direction n of p of currentpen) scaled d))
+enddef ;
+
+% nice: currentpicture := inverted currentpicture ;
+
+primarydef p uncolored c =
+  if color p :
+    c - p
+  else :
+      image
+        (for i within p :
+           addto currentpicture
+           if stroked i or filled i :
+             if filled i : contour else : doublepath fi pathpart i
+             dashed dashpart i withpen penpart i
+           else :
+             also i
+           fi
+           withcolor c-(redpart i, greenpart i, bluepart i) ;
+         endfor ; )
+  fi
+enddef ;
+
+vardef inverted primary p =
+  (p uncolored white)
+enddef ;
+
+% primarydef p softened c =
+%   if color p :
+%     tripled(c) * p
+%   else :
+%     image
+%       (save cc ; color cc ; cc := tripled(c) ;
+%        for i within p :
+%          addto currentpicture
+%          if stroked i or filled i :
+%            if filled i : contour else : doublepath fi pathpart i
+%            dashed dashpart i withpen penpart i
+%          else :
+%           also i
+%          fi
+%          withcolor (redpart   cc * redpart   i,
+%                     greenpart cc * greenpart i,
+%                     bluepart  cc * bluepart  i) ;
+%        endfor ;)
+%   fi
+% enddef ;
+
+primarydef p softened c =
+  begingroup
+  save cc ; color cc ; cc := tripled(c) ;
+  if color p :
+    (redpart   cc * redpart   p,
+     greenpart cc * greenpart p,
+     bluepart  cc * bluepart  p)
+  else :
+    image
+      (for i within p :
+         addto currentpicture
+         if stroked i or filled i :
+           if filled i : contour else : doublepath fi pathpart i
+           dashed dashpart i withpen penpart i
+         else :
+          also i
+         fi
+         withcolor (redpart   cc * redpart   i,
+                    greenpart cc * greenpart i,
+                    bluepart  cc * bluepart  i) ;
+       endfor ;)
+  fi
+  endgroup
+enddef ;
+
+vardef grayed primary p =
+  if color p :
+    tripled(.30redpart p+.59greenpart p+.11bluepart p)
+  else :
+    image
+      (for i within p :
+         addto currentpicture
+         if stroked i or filled i :
+           if filled i : contour else : doublepath fi pathpart i
+           dashed dashpart i withpen penpart i
+         else :
+           also i
+         fi
+         withcolor tripled(.30redpart i+.59greenpart i+.11bluepart i) ;
+       endfor ; )
+  fi
+enddef ;
+
+% yes or no: "text" infont "cmr12" at 24pt ;
+
+% let normalinfont = infont ;
+%
+% numeric lastfontsize ; lastfontsize = fontsize defaultfont ;
+%
+% def infont primary name =  % no vardef, no expr
+%   hide(lastfontsize := fontsize name) % no ;
+%   normalinfont name
+% enddef ;
+%
+% def scaledat expr size =
+%   scaled (size/lastfontsize)
+% enddef ;
+%
+% let at = scaledat ;
+
+% like decimal
+
+def condition primary b = if b : "true" else : "false" fi enddef ;
+
+% undocumented
+
+primarydef p stretched s =
+  begingroup
+% save pp ; path pp ; pp := p scaled s ;
+  save pp ; path pp ; pp := p xyscaled s ;
+  (pp shifted ((point 0 of p) - (point 0 of pp)))
+  endgroup
+enddef ;
+
+% yes or no, untested -)
+
+def xshifted expr dx = shifted(dx,0) enddef ;
+def yshifted expr dy = shifted(0,dy) enddef ;
+
+% also handy
+
+% right: str = readfrom ("abc" & ".def" ) ;
+% wrong: str = readfrom  "abc" & ".def"   ;
+
+% Every 62th read fails so we need to try again!
+
+% def readfile (expr name) =
+%   if (readfrom (name) <> EOF) :
+%     scantokens("input " & name & ";") ;
+%   elseif (readfrom (name) <> EOF) :
+%     scantokens("input " & name & ";") ;
+%   fi ;
+%   closefrom (name) ;
+% enddef ;
+%
+% this sometimes fails on the elseif, so :
+%
+
+def readfile (expr name) =
+  begingroup ; save ok ; boolean ok ;
+  if (readfrom (name) <> EOF) :
+    ok := false ;
+  elseif (readfrom (name) <> EOF) :
+    ok := false ;
+  else :
+    ok := true ;
+  fi ;
+  if not ok :
+    scantokens("input " & name & " ") ;
+  fi ;
+  closefrom (name) ;
+  endgroup ;
+enddef ;
+
+% permits redefinition of end in macro
+
+inner end ;
+
+% real fun
+
+let normalwithcolor = withcolor ;
+
+def remapcolors =
+  def withcolor primary c = normalwithcolor remappedcolor(c) enddef ;
+enddef ;
+
+def normalcolors =
+  let withcolor = normalwithcolor ;
+enddef ;
+
+def resetcolormap =
+  color color_map[][][] ;
+  normalcolors ;
+enddef ;
+
+resetcolormap ;
+
+% color_map_resolution := 1000 ;
+%
+% def r_color primary c = round(color_map_resolution*redpart   c) enddef ;
+% def g_color primary c = round(color_map_resolution*greenpart c) enddef ;
+% def b_color primary c = round(color_map_resolution*bluepart  c) enddef ;
+
+def r_color primary c = redpart   c enddef ;
+def g_color primary c = greenpart c enddef ;
+def b_color primary c = bluepart  c enddef ;
+
+def remapcolor(expr old, new) =
+  color_map[r_color old][g_color old][b_color old] := new ;
+enddef ;
+
+def remappedcolor(expr c) =
+  if known color_map[r_color c][g_color c][b_color c] :
+    color_map[r_color c][g_color c][b_color c]
+  else :
+    c
+  fi
+enddef ;
+
+% def refill  suffix c = do_repath (1) (c) enddef ;
+% def redraw  suffix c = do_repath (2) (c) enddef ;
+% def recolor suffix c = do_repath (0) (c) enddef ;
+%
+% color refillbackground ; refillbackground := (1,1,1) ;
+%
+% def do_repath (expr mode) (suffix c) text t = % can it be stroked and filled at the same time ?
+%   begingroup ;
+%   if mode=0 : save withcolor ; remapcolors ; fi ;
+%   save _c_, _cc_, _f_, _b_ ; picture _c_, _cc_ ; color _f_ ; path _b_ ;
+%   _c_ := c ; _b_ := boundingbox c ; c := nullpicture ;
+%   for i within _c_ :
+%     _f_ := (redpart i, greenpart i, bluepart i) ;
+%     if     bounded i :
+%       setbounds c to pathpart i ;
+%     elseif clipped i :
+%       clip c to pathpart i ;
+%     elseif stroked i :
+%       addto c doublepath pathpart i
+%         dashed dashpart i withpen penpart i
+%         withcolor _f_ % (redpart i, greenpart i, bluepart i)
+%         if mode=2 : t fi ;
+%     elseif filled  i :
+%       addto c contour pathpart i
+%         withcolor _f_
+%         if (mode=1) and (_f_<>refillbackground) : t fi ;
+%     else :
+%       addto c also i ;
+%     fi ;
+%   endfor ;
+%   setbounds c to _b_ ;
+%   endgroup ;
+% enddef ;
+
+% Thanks to Jens-Uwe Morawski for pointing out that we need
+% to treat bounded and clipped components as local pictures.
+
+def recolor   suffix p = p := repathed (0,p) enddef ;
+def refill    suffix p = p := repathed (1,p) enddef ;
+def redraw    suffix p = p := repathed (2,p) enddef ;
+def retext    suffix p = p := repathed (3,p) enddef ;
+def untext    suffix p = p := repathed (4,p) enddef ;
+
+% primarydef p recolored t = repathed(0,p) t enddef ;
+% primarydef p refilled  t = repathed(1,p) t enddef ;
+% primarydef p redrawn   t = repathed(2,p) t enddef ;
+% primarydef p retexted  t = repathed(3,p) t enddef ;
+% primarydef p untexted  t = repathed(4,p) t enddef ;
+
+color refillbackground ; refillbackground := (1,1,1) ;
+
+% vardef repathed (expr mode, p) text t =
+%   begingroup ;
+%   if mode=0 : save withcolor ; remapcolors ; fi ;
+%   save _p_, _pp_, _f_, _b_, _t_ ;
+%   picture _p_, _pp_ ; color _f_ ; path _b_ ; transform _t_ ;
+%   _b_ := boundingbox p ; _p_ := nullpicture ;
+%   for i within p :
+%     _f_ := (redpart i, greenpart i, bluepart i) ;
+%     if     bounded i :
+%       _pp_ := repathed(mode,i) t ;
+%       setbounds _pp_ to pathpart i ;
+%       addto _p_ also _pp_ ;
+%     elseif clipped i :
+%       _pp_ := repathed(mode,i) t ;
+%       clip _pp_ to pathpart i ;
+%       addto _p_ also _pp_ ;
+%     elseif stroked i :
+%       addto _p_ doublepath pathpart i
+%         dashed dashpart i withpen penpart i
+%         withcolor _f_ % (redpart i, greenpart i, bluepart i)
+%         if mode=2 : t fi ;
+%     elseif filled  i :
+%       addto _p_ contour pathpart i
+%         withcolor _f_
+%         if (mode=1) and (_f_<>refillbackground) : t fi ;
+%     elseif textual i : % textpart i <> "" :
+%       if mode <> 4 :
+%         % transform _t_ ;
+%         % (xpart _t_, xxpart _t_, xypart _t_)  = (xpart  i, xxpart i, xypart i) ;
+%         % (ypart _t_, yypart _t_, yxpart _t_)  = (ypart  i, yypart i, yxpart i) ;
+%         % addto _p_ also
+%         %   textpart i infont fontpart i % todo : other font
+%         %   transformed _t_
+%         %   withpen penpart i
+%         %   withcolor _f_
+%         %   if mode=3 : t fi ;
+%         addto _p_ also i if mode=3 : t fi ;
+%       fi ;
+%     else :
+%       addto _p_ also i ;
+%     fi ;
+%   endfor ;
+%   setbounds _p_ to _b_ ;
+%   _p_
+%   endgroup
+% enddef ;
+
+def restroke  suffix p = p := repathed (21,p) enddef ; % keep attributes
+def reprocess suffix p = p := repathed (22,p) enddef ; % no attributes
+
+% also 11 and 12
+
+vardef repathed (expr mode, p) text t =
+  begingroup ;
+  if mode=0 : save withcolor ; remapcolors ; fi ;
+  save _p_, _pp_, _ppp_, _f_, _b_, _t_ ;
+  picture _p_, _pp_, _ppp_ ; color _f_ ; path _b_ ; transform _t_ ;
+  _b_ := boundingbox p ; _p_ := nullpicture ;
+  for i within p :
+    _f_ := (redpart i, greenpart i, bluepart i) ;
+    if     bounded i :
+      _pp_ := repathed(mode,i) t ;
+      setbounds _pp_ to pathpart i ;
+      addto _p_ also _pp_ ;
+    elseif clipped i :
+      _pp_ := repathed(mode,i) t ;
+      clip _pp_ to pathpart i ;
+      addto _p_ also _pp_ ;
+    elseif stroked i :
+      if mode=21 :
+        _ppp_ := i ; % indirectness is needed
+        addto _p_ also image(scantokens(t & " pathpart _ppp_")
+          dashed dashpart i withpen penpart i
+          withcolor _f_ ; ) ;
+      elseif mode=22 :
+        _ppp_ := i ; % indirectness is needed
+        addto _p_ also image(scantokens(t & " pathpart _ppp_")) ;
+      else :
+        addto _p_ doublepath pathpart i
+          dashed dashpart i withpen penpart i
+          withcolor _f_ % (redpart i, greenpart i, bluepart i)
+          if mode=2 : t fi ;
+      fi ;
+    elseif filled  i :
+      if mode=11 :
+        _ppp_ := i ; % indirectness is needed
+        addto _p_ also image(scantokens(t & " pathpart _ppp_")
+          withcolor _f_ ; ) ;
+      elseif mode=12 :
+        _ppp_ := i ; % indirectness is needed
+        addto _p_ also image(scantokens(t & " pathpart _ppp_")) ;
+      else :
+        addto _p_ contour pathpart i
+          withcolor _f_
+        if (mode=1) and (_f_<>refillbackground) : t fi ;
+      fi ;
+    elseif textual i : % textpart i <> "" :
+      if mode <> 4 :
+        % transform _t_ ;
+        % (xpart _t_, xxpart _t_, xypart _t_)  = (xpart  i, xxpart i, xypart i) ;
+        % (ypart _t_, yypart _t_, yxpart _t_)  = (ypart  i, yypart i, yxpart i) ;
+        % addto _p_ also
+        %   textpart i infont fontpart i % todo : other font
+        %   transformed _t_
+        %   withpen penpart i
+        %   withcolor _f_
+        %   if mode=3 : t fi ;
+        addto _p_ also i if mode=3 : t fi ;
+      fi ;
+    else :
+      addto _p_ also i ;
+    fi ;
+  endfor ;
+  setbounds _p_ to _b_ ;
+  _p_
+  endgroup
+enddef ;
+
+% After a question of Denis on how to erase a z variable, Jacko
+% suggested to assign whatever to x and y. So a clearz
+% variable can be defined as:
+%
+% vardef clearz@# =
+%   x@# := whatever ;
+%   y@# := whatever ;
+% enddef ;
+%
+% but Jacko suggested a redefinition of clearxy:
+%
+% def clearxy text s =
+%  clearxy_index_:=0;
+%  for $:=s:
+%    clearxy_index_:=clearxy_index_+1; endfor;
+%  if clearxy_index_=0:
+%    save x,y;
+%  else:
+%    forsuffixes $:=s: x$:=whatever; y$:=whatever; endfor;
+%  fi
+% enddef;
+%
+% which i decided to simplify to:
+
+def clearxy text s =
+  if false for $ := s : or true endfor :
+    forsuffixes $ := s : x$ := whatever ; y$ := whatever ; endfor ;
+  else :
+    save x, y ;
+  fi
+enddef ;
+
+% so now we can say: clearxy ; as well as clearxy 1, 2, 3 ;
+
+% show x0 ; z0 = (10,10) ;
+% show x0 ; x0 := whatever ; y0 := whatever ;
+% show x0 ; z0 = (20,20) ;
+% show x0 ; clearxy 0 ;
+% show x0 ; z0 = (30,30) ;
+
+primarydef p smoothed d =
+  (p llmoved (-xpart paired(d),0) -- p lrmoved (-xpart paired(d),0) {right} ..
+   p lrmoved (0,-ypart paired(d)) -- p urmoved (0,-ypart paired(d)) {up}    ..
+   p urmoved (-xpart paired(d),0) -- p ulmoved (-xpart paired(d),0) {left}  ..
+   p ulmoved (0,-ypart paired(d)) -- p llmoved (0,-ypart paired(d)) {down}  .. cycle)
+enddef ;
+
+primarydef p cornered c =
+  ((point 0 of p) shifted (c*(unitvector(point 1 of p - point 0 of p))) --
+   for i=1 upto length(p) :
+     (point i-1 of p) shifted (c*(unitvector(point i   of p - point i-1 of p))) --
+     (point i   of p) shifted (c*(unitvector(point i-1 of p - point i   of p))) ..
+     controls point i of p ..
+   endfor cycle)
+enddef ;
+
+% cmyk color support
+
+vardef cmyk(expr c,m,y,k) =
+  (1-c-k,1-m-k,1-y-k)
+enddef ;
+
+% handy
+
+vardef bbwidth  (expr p) =
+  (if known p :
+     if path p or picture p :
+       xpart (lrcorner p - llcorner p)
+     else : 0 fi else : 0
+   fi )
+enddef ;
+
+vardef bbheight (expr p) =
+  (if known p : if path p or picture p :
+     ypart (urcorner p - lrcorner p)
+     else : 0 fi else : 0
+   fi)
+enddef ;
+
+color nocolor ; numeric noline ; % both unknown signals
+
+def dowithpath (expr p, lw, lc, bc) =
+  if known p :
+    if known bc :
+      fill p withcolor bc ;
+    fi ;
+    if known lw and known lc :
+      draw p withpen pencircle scaled lw withcolor lc ;
+    elseif known lw :
+      draw p withpen pencircle scaled lw ;
+    elseif known lc :
+      draw p withcolor lc ;
+    fi ;
+  fi ;
+enddef ;
+
+% result from metafont discussion list (denisr/boguslawj)
+
+def ]]  = ] ] enddef ; def ]]] = ] ] ] enddef ;
+def [[  = [ [ enddef ; def [[[ = [ [ [ enddef ;
+
+% not perfect, but useful since it removes redundant points.
+
+% vardef dostraightened(expr sign, p) =
+%   if length(p)>2 : % was 1, but straight lines are ok
+%     save pp ; path pp ;
+%     pp := point 0 of p ;
+%     for i=1 upto length(p)-1 :
+%       if round(point i of p) <> round(point length(pp) of pp) :
+%         pp := pp -- point i of p ;
+%       fi ;
+%     endfor ;
+%     save n, ok ; numeric n ; boolean ok ;
+%     n := length(pp) ; ok := false ;
+% if n>2 :
+%     for i=0 upto n : % evt hier ook round
+%      if unitvector(round(point i                        of pp  -
+%                    point if i=0 : n else : i-1 fi of pp)) <>
+%  sign * unitvector(round(point if i=n : 0 else : i+1 fi of pp  -
+%                    point i                        of pp)) :
+%         if ok : -- else : ok := true ; fi point i of pp
+%       fi
+%     endfor
+%     if ok and (cycle p) : -- cycle fi
+% else :
+%   pp
+% fi
+%   else :
+%     p
+%   fi
+% enddef ;
+
+% vardef simplified expr p =
+%   (reverse dostraightened(+1,dostraightened(+1,reverse p)))
+% enddef ;
+
+% vardef unspiked   expr p =
+%   (reverse dostraightened(-1,dostraightened(-1,reverse p)))
+% enddef ;
+
+% simplified : remove same points as well as redundant points
+% unspiked   : remove same points as well as areas with zero distance
+
+vardef dostraightened(expr sign, p) =
+  save _p_, _q_ ; path _p_, _q_ ;
+  _p_ := p ;
+  forever :
+    _q_ := dodostraightened(sign, _p_) ;
+    exitif length(_p_) = length(_q_) ;
+    _p_ := _q_ ;
+  endfor ;
+  _q_
+enddef ;
+
+vardef dodostraightened(expr sign, p) =
+  if length(p)>2 : % was 1, but straight lines are ok
+    save pp ; path pp ;
+    pp := point 0 of p ;
+    for i=1 upto length(p)-1 :
+      if round(point i of p) <> round(point length(pp) of pp) :
+        pp := pp -- point i of p ;
+      fi ;
+    endfor ;
+    save n, ok ; numeric n ; boolean ok ;
+    n := length(pp) ; ok := false ;
+    if n>2 :
+      for i=0 upto n : % evt hier ook round
+        if unitvector(round(point i                        of pp  -
+                            point if i=0 : n else : i-1 fi of pp)) <>
+    sign * unitvector(round(point if i=n : 0 else : i+1 fi of pp  -
+                            point i                        of pp)) :
+          if ok : -- else : ok := true ; fi point i of pp
+        fi
+      endfor
+      if ok and (cycle p) : -- cycle fi
+    else :
+      pp
+    fi
+  else :
+    p
+  fi
+enddef ;
+
+% vardef simplified expr p =
+%   dostraightened(+1,p)
+% enddef ;
+
+% vardef unspiked   expr p =
+%   dostraightened(-1,p)
+% enddef ;
+
+vardef simplified expr p =
+  (reverse dostraightened(+1,dostraightened(+1,reverse p)))
+enddef ;
+
+vardef unspiked   expr p =
+  (reverse dostraightened(-1,dostraightened(-1,reverse p)))
+enddef ;
+
+% path p ;
+% p := (2cm,1cm) -- (2cm,1cm) -- (2cm,1cm) -- (3cm,1cm) --
+%      (4cm,1cm) -- (4cm,2cm) -- (4cm,2.5cm) -- (4cm,3cm) --
+%      (3cm,3cm) -- (2cm,3cm) -- (1cm,3cm) -- (-1cm,3cm) --
+%      .5[(-1cm,3cm),(1cm,1cm)] -- (1cm,1cm) -- cycle ;
+%
+% p := unitcircle scaled 4cm ;
+%
+% drawpath p ; drawpoints p ; drawpointlabels p ;
+% p := p shifted (4cm,0) ; p := straightened p ;
+% drawpath p ; drawpoints p ; drawpointlabels p ;
+% p := p shifted (4cm,0) ; p := straightened p ;
+% drawpath p ; drawpoints p ; drawpointlabels p ;
+
+% new
+
+path originpath ; originpath := origin -- cycle ;
+
+vardef unitvector primary z =
+  if abs z = abs origin : z else : z/abs z fi
+enddef;
+
+% also new
+
+vardef anchored@#(expr p, z) =
+  p shifted (z + (labxf@#*lrcorner p + labyf@#*ulcorner p
+       + (1-labxf@#-labyf@#)*llcorner p))
+enddef ;
+
+% epsed(1.2345)
+
+vardef epsed (expr e) =
+  e if e>0 : + eps elseif e<0 : - eps fi
+enddef ;
+
+% handy
+
+def withgray primary g =
+  withcolor (g,g,g)
+enddef ;
+
+% for metafun
+
+if unknown darkred    : color darkred    ; darkred    := .625(1,0,0) fi ;
+if unknown darkyellow : color darkyellow ; darkyellow := .625(1,1,0) fi ;
+if unknown darkgray   : color darkgray   ; darkgray   := .625(1,1,1) fi ;
+if unknown lightgray  : color lightgray  ; lightgray  := .875(1,1,1) fi ;
+
+% an improved plain mp macro
+
+vardef center primary p =
+  if pair p : p else : .5[llcorner p, urcorner p] fi
+enddef;
+
+% new, yet undocumented
+
+vardef rangepath (expr p, d, a) =
+  (if length p>0 :
+     (d*unitvector(direction 0 of p) rotated a)
+      shifted point 0 of p
+     -- p --
+     (d*unitvector(direction length(p) of p) rotated a)
+      shifted point length(p) of p
+   else :
+     p
+   fi)
+enddef ;
+
+% under construction
+
+vardef straightpath(expr a, b, method) =
+  if (method<1) or (method>6)  :
+    (a--b)
+  elseif method = 1 :
+    (a --
+     if xpart a > xpart b :
+       if ypart a > ypart b :
+         (xpart b,ypart a) --
+       elseif ypart a < ypart b :
+         (xpart a,ypart b) --
+       fi
+     elseif xpart a < xpart b :
+       if ypart a > ypart b :
+         (xpart a,ypart b) --
+       elseif ypart a < ypart b :
+         (xpart b,ypart a) --
+        fi
+    fi
+    b)
+  elseif method = 3 :
+    (a --
+     if xpart a > xpart b :
+       (xpart b,ypart a) --
+     elseif xpart a < xpart b :
+       (xpart a,ypart b) --
+     fi
+     b)
+  elseif method = 5 :
+    (a --
+     if ypart a > ypart b :
+       (xpart b,ypart a) --
+     elseif ypart a < ypart b :
+     (xpart a,ypart b) --
+     fi
+     b)
+  else :
+    (reverse straightpath(b,a,method-1))
+  fi
+enddef ;
+
+% handy for myself
+
+def addbackground text t =
+  begingroup ; save p ; picture p ;
+  p := currentpicture ; currentpicture := nullpicture ;
+  fill boundingbox p t ; addto currentpicture also p ;
+  endgroup ;
+enddef ;
+
+% makes a (line) into an infinite one (handy for calculating
+% intersection points
+
+vardef infinite expr p =
+  (-infinity*unitvector(direction 0 of p)
+    shifted point 0 of p
+   -- p --
+   +infinity*unitvector(direction length(p) of p)
+    shifted point length(p) of p)
+enddef ;
+
+% obscure macros: create var from string and replace - and :
+% (needed for process color id's)
+
+string _clean_ascii_[] ;
+
+def register_dirty_chars(expr str) =
+    for i = 0 upto length(str)-1 :
+        _clean_ascii_[ASCII substring(i,i+1) of str] := "_" ;
+    endfor ;
+enddef ;
+
+register_dirty_chars("+-*/:;., ") ;
+
+vardef cleanstring (expr s) =
+  save ss ; string ss, si ; ss = "" ; save i ;
+  for i=0 upto length(s) :
+    si := substring(i,i+1) of s ;
+    ss := ss & if known _clean_ascii_[ASCII si] : _clean_ascii_[ASCII si] else : si fi ;
+  endfor ;
+  ss
+enddef ;
+
+vardef asciistring (expr s) =
+  save ss ; string ss, si ; ss = "" ; save i ;
+  for i=0 upto length(s) :
+    si := substring(i,i+1) of s ;
+    if (ASCII si >= ASCII "0") and (ASCII si <= ASCII "9") :
+        ss := ss & char(scantokens(si) + ASCII "A") ;
+    else :
+        ss := ss & si ;
+    fi ;
+  endfor ;
+  ss
+enddef ;
+
+vardef setunstringed (expr s, v) =
+  scantokens(cleanstring(s)) := v ;
+enddef ;
+
+vardef setunstringed (expr s, v) =
+  scantokens(cleanstring(s)) := v ;
+enddef ;
+
+vardef getunstringed (expr s) =
+  scantokens(cleanstring(s))
+enddef ;
+
+vardef unstringed (expr s) =
+  expandafter known scantokens(cleanstring(s))
+enddef ;
+
+% new
+
+vardef colorpart(expr i) =
+  (redpart i, greenpart i,bluepart i)
+enddef ;
+
+% for david arnold:
+
+% showgrid(-5,10,1cm,-10,10,1cm);
+
+def showgrid (expr MinX, MaxX, DeltaX, MinY, MaxY, DeltaY)=
+  begingroup
+    save defaultfont, defaultscale, size ;
+    string  defaultfont  ; defaultfont  := "cmtt10"; % i.e. infofont
+    numeric defaultscale ; defaultscale := 8pt / fontsize defaultfont;
+    numeric size         ; size         := 2pt ;
+    for x=MinX upto MaxX :
+      for y=MinY upto MaxY :
+    	draw (x*DeltaX, y*DeltaY)
+          withpen pencircle scaled
+          if (x mod 5 = 0) and (y mod 5 = 0) :
+            1.5size withcolor .50white
+          else :
+               size withcolor .75white
+          fi ;
+      endfor ;
+    endfor ;
+    for x=MinX upto MaxX:
+      label.bot(decimal x, (x*DeltaX,-size));
+    endfor ;
+    for y=MinY upto MaxY:
+      label.lft(decimal y, (-size,y*DeltaY)) ;
+    endfor ;
+  endgroup
+enddef;
+
+% new, handy for:
+%
+% \startuseMPgraphic{map}{n}
+%   \includeMPgraphic{map:germany} ;
+%   c_phantom (\MPvar{n}<1) (
+%     fill map_germany withcolor \MPcolor{lightgray} ;
+%     draw map_germany withpen pencircle scaled 1pt withcolor \MPcolor{darkgray} ;
+%   ) ;
+%   \includeMPgraphic{map:austria} ;
+%   c_phantom (\MPvar{n}<2) (
+%     fill map_austria withcolor \MPcolor{lightgray} ;
+%     draw map_austria withpen pencircle scaled 1pt withcolor \MPcolor{darkgray} ;
+%   ) ;
+%   c_phantom (\MPvar{n}<3) (
+%   \includeMPgraphic{map:swiss} ;
+%     fill map_swiss withcolor \MPcolor{lightgray} ;
+%     draw map_swiss withpen pencircle scaled 1pt withcolor \MPcolor{darkgray}  ;
+%   ) ;
+%   c_phantom (\MPvar{n}<4) (
+%   \includeMPgraphic{map:luxembourg} ;
+%     fill map_luxembourg withcolor \MPcolor{lightgray} ;
+%     draw map_luxembourg withpen pencircle scaled 1pt withcolor \MPcolor{darkgray}  ;
+%   ) ;
+% \stopuseMPgraphic
+%
+% \useMPgraphic{map}{n=3}
+
+vardef phantom (text t) =
+   picture _p_ ; _p_ := image(t) ; addto _p_ also currentpicture ;
+   setbounds currentpicture to boundingbox _p_ ;
+enddef ;
+
+vardef c_phantom (expr b) (text t) =
+   if b :
+     picture _p_ ; _p_ := image(t) ; addto _p_ also currentpicture ;
+     setbounds currentpicture to boundingbox _p_ ;
+   else :
+     t ;
+   fi ;
+enddef ;
+
+% done
+
+endinput ;