new metapost package blockdraw_mp (22jan07)

git-svn-id: svn://tug.org/texlive/trunk@5381 c570f23f-e606-0410-a88d-b1316a301751

6 files changed, 820 insertions, 0 deletions

diff --git a/Master/texmf-dist/metapost/blockdraw_mp/blockdraw.mp b/Master/texmf-dist/metapost/blockdraw_mp/blockdraw.mp
new file mode 100644
index 00000000000..1396f574ea4
--- /dev/null
+++ b/Master/texmf-dist/metapost/blockdraw_mp/blockdraw.mp
@@ -0,0 +1,310 @@
+%% blockdraw.mp
+%% Copyright 2006 Henrik Tidefelt
+% 
+% This work may be distributed and/or modified under the 
+% conditions of the LaTeX Project Public License, either version 1.3 
+% of this license or (at your option) any later version.
+% The latest version of this license is in 
+% http://www.latex-project.org/lppl.txt 
+% and version 1.3 or later is part of all distributions of LaTeX 
+% version 2005/12/01 or later.
+% 
+% This work has the LPPL maintenance status `maintained´.
+% 
+% The Current Maintainer of this work is Henrik Tidefelt,
+% tidefelt@isy.liu.se.
+% 
+% This work, referred to as blockdraw.mp, consists of the files
+%   shiftoff.mp
+%   blockdraw.mp
+%   bondgraph.mp
+%   blockdraw_mp.pdf
+
+numeric longblockrx;
+numeric longblockry;
+numeric smallblockr;
+longblockrx := 0.7cm;
+longblockry := 0.4cm;
+smallblockr := 0.3cm;
+
+numeric connectionlw;
+numeric blocklw;
+connectionlw := 0.8pt;
+blocklw = connectionlw;
+
+numeric textscale;
+textscale := 1;
+
+boolean implicitdraw;
+implicitdraw := true;
+
+input shiftoff;
+
+def sizedblock(expr txt, z, rx, ry ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := nullpicture;
+    addto tmppic also shiftoff( txt scaled textscale, to_center );
+    addto tmppic doublepath (-rx,-ry)--(-rx,ry)--(rx,ry)--(rx,-ry)--cycle withpen pencircle scaled blocklw;
+    tmppic := tmppic shifted z;
+    if implicitdraw:
+      draw tmppic;
+    fi
+    tmppic
+  endgroup
+enddef;
+def longblock(expr txt, z ) =
+  sizedblock( txt, z, longblockrx, longblockry )
+enddef;
+def squareblock(expr txt, z ) =
+  sizedblock( txt, z, smallblockr, smallblockr )
+enddef;
+def roundblock(expr txt, z ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := nullpicture;
+    addto tmppic also shiftoff( txt scaled textscale, to_center );
+    addto tmppic doublepath (smallblockr,0)...(0,smallblockr)...(-smallblockr,0)...(0,-smallblockr)...cycle withpen pencircle scaled blocklw;
+    tmppic := tmppic shifted z;
+    if implicitdraw:
+      draw tmppic;
+    fi
+    tmppic
+  endgroup
+enddef;
+def splitdot(expr z ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := nullpicture;
+    addto tmppic contour fullcircle scaled 2.5connectionlw shifted z;
+    if implicitdraw:
+      draw tmppic;
+    fi
+    tmppic
+  endgroup
+enddef;
+def termcircle(expr z ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := nullpicture;
+    addto tmppic doublepath fullcircle scaled 7connectionlw shifted z;
+    if implicitdraw:
+      draw tmppic;
+    fi
+    tmppic
+  endgroup
+enddef;
+def pointpicture(expr z ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := nullpicture;
+    addto tmppic contour fullcircle scaled 0 shifted z;
+    tmppic
+  endgroup
+enddef;
+
+def mspoint( expr pth, mediation, slide ) =
+(point (arctime mediation * arclength(pth) + slide of pth) of pth)
+enddef;
+def hhconnect(expr pa, pb, mediation, slide ) =
+  begingroup
+    save mid, respath;
+    numeric mid;
+    path respath;
+    mid := (mediation)[ xpart pa, xpart pb ] + (if (xpart pb) > (xpart pa): 1 else: -1 fi) * slide;
+    respath := pa--( mid, ypart pa )--( mid, ypart pb )--pb;
+    if implicitdraw:
+      drawarrow respath withpen pencircle scaled connectionlw;
+    fi
+    respath
+  endgroup
+enddef;
+def vvconnect(expr pa, pb, mediation, slide ) =
+  begingroup
+    save mid, respath;
+    numeric mid;
+    path respath;
+    mid := (mediation)[ ypart pa, ypart pb ] + (if (ypart pb) > (ypart pa): 1 else: -1 fi) * slide;
+    respath := pa--( xpart pa, mid )--( xpart pb, mid )--pb;
+    if implicitdraw:
+      drawarrow respath withpen pencircle scaled connectionlw;
+    fi
+    respath
+  endgroup
+enddef;
+def hvconnect(expr pa, pb ) =
+  begingroup
+    save respath;
+    path respath;
+    respath := pa--( xpart pb, ypart pa )--pb;
+    if implicitdraw:
+      drawarrow respath withpen pencircle scaled connectionlw;
+    fi
+    respath
+  endgroup
+enddef;
+def vhconnect(expr pa, pb ) =
+  begingroup
+    save respath;
+    path respath;
+    respath := pa--( xpart pa, ypart pb )--pb;
+    if implicitdraw:
+      drawarrow respath withpen pencircle scaled connectionlw;
+    fi
+    respath
+  endgroup
+enddef;
+
+def conlabel(expr shiftdir, txt, z ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := shiftoffwlm( txt scaled textscale, shiftdir ) shifted z;
+    if implicitdraw:
+      draw tmppic;
+    fi
+    tmppic
+  endgroup
+enddef;
+
+def leftpoint(expr pic, n, i ) =
+  (i/(n+1))[llcorner pic,ulcorner pic]
+enddef;
+def rightpoint(expr pic, n, i ) =
+  (i/(n+1))[lrcorner pic,urcorner pic]
+enddef;
+def bottompoint(expr pic, n, i ) =
+  (i/(n+1))[llcorner pic,lrcorner pic]
+enddef;
+def toppoint(expr pic, n, i ) =
+  (i/(n+1))[ulcorner pic,urcorner pic]
+enddef;
+def llconnect(expr pica, picb, slide ) =
+  begingroup
+    hhconnect( leftpoint( pica, 1, 1 ), leftpoint( picb, 1, 1 ), 0.5, slide )
+  endgroup
+enddef;
+def rrconnect(expr pica, picb, slide ) =
+  begingroup
+    hhconnect( rightpoint( pica, 1, 1 ), rightpoint( picb, 1, 1 ), 0.5, slide )
+  endgroup
+enddef;
+def ttconnect(expr pica, picb, slide ) =
+  begingroup
+    vvconnect( toppoint( pica, 1, 1 ), toppoint( picb, 1, 1 ), 0.5, slide )
+  endgroup
+enddef;
+def bbconnect(expr pica, picb, slide ) =
+  begingroup
+    vvconnect( bottompoint( pica, 1, 1 ), bottompoint( picb, 1, 1 ), 0.5, slide )
+  endgroup
+enddef;
+def lrconnect(expr pica, picb ) =
+  begingroup
+    hhconnect( leftpoint( pica, 1, 1 ), rightpoint( picb, 1, 1 ), 0.5, 0 )
+  endgroup
+enddef;
+def rlconnect(expr pica, picb ) =
+  begingroup
+    hhconnect( rightpoint( pica, 1, 1 ), leftpoint( picb, 1, 1 ), 0.5, 0 )
+  endgroup
+enddef;
+def btconnect(expr pica, picb ) =
+  begingroup
+    vvconnect( bottompoint( pica, 1, 1 ), toppoint( picb, 1, 1 ), 0.5, 0 )
+  endgroup
+enddef;
+def tbconnect(expr pica, picb ) =
+  begingroup
+    vvconnect( toppoint( pica, 1, 1 ), bottompoint( picb, 1, 1 ), 0.5, 0 )
+  endgroup
+enddef;
+def ltconnect(expr pica, picb ) =
+  begingroup
+    hvconnect( leftpoint( pica, 1, 1 ), toppoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+def lbconnect(expr pica, picb ) =
+  begingroup
+    hvconnect( leftpoint( pica, 1, 1 ), bottompoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+def rtconnect(expr pica, picb ) =
+  begingroup
+    hvconnect( rightpoint( pica, 1, 1 ), toppoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+def rbconnect(expr pica, picb ) =
+  begingroup
+    hvconnect( rightpoint( pica, 1, 1 ), bottompoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+def tlconnect(expr pica, picb ) =
+  begingroup
+    vhconnect( toppoint( pica, 1, 1 ), leftpoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+def trconnect(expr pica, picb ) =
+  begingroup
+    vhconnect( toppoint( pica, 1, 1 ), rightpoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+def blconnect(expr pica, picb ) =
+  begingroup
+    vhconnect( bottompoint( pica, 1, 1 ), leftpoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+def brconnect(expr pica, picb ) =
+  begingroup
+    vhconnect( bottompoint( pica, 1, 1 ), rightpoint( picb, 1, 1 ) )
+  endgroup
+enddef;
+
+def connect(expr pica, picb ) =
+  begingroup
+    save rxa, rya, rxb, ryb;
+    numeric rxa;
+    numeric rya;
+    numeric rxb;
+    numeric ryb;
+    save ca, cb;
+    pair ca;
+    pair cb;
+    rxa = 0.5 * ((xpart lrcorner pica) - (xpart llcorner pica));
+    rya = 0.5 * ((ypart ulcorner pica) - (ypart llcorner pica));
+    rxb = 0.5 * ((xpart lrcorner picb) - (xpart llcorner picb));
+    ryb = 0.5 * ((ypart ulcorner picb) - (ypart llcorner picb));
+    ca = center pica;
+    cb = center picb;
+    if (xpart ca) < (xpart cb) - ( rxa + rxb ):
+      if (ypart ca) < (ypart cb) - ( rya + ryb ):
+	rbconnect( pica, picb )
+      elseif (ypart ca) > (ypart cb) + ( rya + ryb ):
+	rtconnect( pica, picb )
+      else:
+	rlconnect( pica, picb )
+      fi
+    elseif (xpart ca) > (xpart cb) + ( rxa + rxb ):
+      if (ypart ca) < (ypart cb) - ( rya + ryb ):
+	lbconnect( pica, picb )
+      elseif (ypart ca) > (ypart cb) + ( rya + ryb ):
+	ltconnect( pica, picb )
+      else:
+	lrconnect( pica, picb )
+      fi
+    else:
+      if (ypart ca) < (ypart cb) - ( rya + ryb ):
+	tbconnect( pica, picb )
+      elseif (ypart ca) > (ypart cb) + ( rya + ryb ):
+	btconnect( pica, picb )
+      else:
+	hvconnect( center pica, center picb )
+      fi
+    fi
+  endgroup
+enddef;
diff --git a/Master/texmf-dist/metapost/blockdraw_mp/bonddemo.mp b/Master/texmf-dist/metapost/blockdraw_mp/bonddemo.mp
new file mode 100644
index 00000000000..3f74bd9abe9
--- /dev/null
+++ b/Master/texmf-dist/metapost/blockdraw_mp/bonddemo.mp
@@ -0,0 +1,63 @@
+verbatimtex
+%& latex
+\documentclass[a4]{article}
+\begin{document}
+etex
+
+input bondgraph;
+def pjunction(expr z ) =
+  junction( btex p etex, z )
+enddef;
+def sjunction(expr z ) =
+  junction( btex s etex, z )
+enddef;
+def tfjunction(expr z, arrowdir, lbl ) =
+  junctionlbl( btex TF etex, arrowdir, lbl, z, true )
+enddef;
+def gyjunction(expr z, arrowdir, lbl ) =
+  junctionlbl( btex GY etex, arrowdir, lbl, z, false )
+enddef;
+
+beginfig( -1 )
+  numeric u;
+  u := 2cm;
+  ahlength := 0.15*u;
+  
+  picture j[];
+  j1 := sjunction( (1u,1u) );
+  j2 := gyjunction( (2u,1u), to_rt, btex $\mu$ etex );
+  j3 := sjunction( (3u,1u) );
+  j4 := tfjunction( (4u,1u), to_rt, btex $r$ etex );
+  j5 := pjunction( (5u,1u) );
+  j6 := sjunction( (5u,-0.5u) );
+  j7 := sjunction( (5u,2u) );
+  
+  tbond( bgconnect( j1, j2 ) );
+  hbond( bgconnect( j2, j3 ) );
+  tbond( bgconnect( j3, j4 ) );
+  tbond( bgconnect( j4, j5 ) );
+  hbond( bgconnect( j5, j6 ) );
+  tbond( bgconnect( j5, j7 ) );
+
+  tbond( terminalfr( j1, btex R: $\phi_{1}(\bullet)$ etex, (1u,0u) ) );
+  hbond( terminalfr( j1, btex I: $m_{1}$ etex, (1u,2u) ) );
+  hbond( terminalfr( j3, btex I: $m_{2}$ etex, (3u,2u) ) );
+  tbond( terminalfr( j3, btex R: $R_{2}$ etex, (center j3)+1u*dir(-120) ) );
+  tbond( terminalfr( j3, btex R: $R_{3}$ etex, (center j3)+1u*dir(-60) ) );
+
+  hbond( terminalto( j6, btex $S_{\mathrm{e}}$ etex, (center j6)+(-1u,0u) ) );
+  hbond( terminalfr( j6, btex I: $m_{3}$ etex, (center j6)+(1u,0u) ) );
+
+  tbond( terminalfr( j7, btex C: $C_{1}$ etex, (4u,2u) ) );
+  tbond( terminalfr( j7, btex R: $R_{1}$ etex, (6u,2u) ) );
+
+  path con;
+  picture lab;
+
+  con := terminalto( j1, btex $S_{\mathrm{e}}$ etex, (0u,1u) );
+  hbond( con );
+  flowlabel( con, btex f etex );
+  effortlabel( con, btex e etex );
+
+endfig;
+end;
diff --git a/Master/texmf-dist/metapost/blockdraw_mp/bondgraph.mp b/Master/texmf-dist/metapost/blockdraw_mp/bondgraph.mp
new file mode 100644
index 00000000000..ba5d861d14d
--- /dev/null
+++ b/Master/texmf-dist/metapost/blockdraw_mp/bondgraph.mp
@@ -0,0 +1,226 @@
+%% bondgraph.mp
+%% Copyright 2007 Henrik Tidefelt
+% 
+% This work may be distributed and/or modified under the 
+% conditions of the LaTeX Project Public License, either version 1.3 
+% of this license or (at your option) any later version.
+% The latest version of this license is in 
+% http://www.latex-project.org/lppl.txt 
+% and version 1.3 or later is part of all distributions of LaTeX 
+% version 2005/12/01 or later.
+% 
+% This work has the LPPL maintenance status `maintained´.
+% 
+% The Current Maintainer of this work is Henrik Tidefelt,
+% tidefelt@isy.liu.se.
+% 
+% This work, referred to as blockdraw.mp, consists of the files
+%   shiftoff.mp
+%   blockdraw.mp
+%   bondgraph.mp
+%   blockdraw_mp.pdf
+%
+%
+% === Notes regarding the backward incompatible changes of 2007-01-21. ===
+%
+% As it was discovered that MetaPost uses the verbatimtex construct only in
+% the file it appears in, it was concluded that package files cannot contain
+% any content that depends on the LaTeX preamble.  In other words, any
+% btex ... etex constructs must be moved from package files to the application
+% sources from where the package files are included.
+%
+% With the definition of, say, p-junction blocks in the application source,
+% it is easy to change notation from the letters "p" and "s" to the numbers
+% "0" and "1".
+%
+% The obvious drawback, beside backward incompatibility, is that this will
+% cause a lot of code replication, making bond graph source files
+% less concise, and require multiple file search-and-replace actions when
+% changing junction notation for a collection of graphs.  However, since
+% MetaPost only allows literal character strings in the btex ... etex
+% construct, these inconveniences seem impossible to work around.  Ideas,
+% anyone?
+
+input blockdraw;
+implicitdraw := false;
+
+boolean junctionimplicitdraw;
+junctionimplicitdraw := true;
+
+boolean useopenbonds;
+useopenbonds := false;
+
+connectionlw := 0.5pt;
+ahlength := 3mm;
+bboxmargin := 1.5mm;
+
+def withbbmargin(expr pic ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic = pic;
+    setbounds tmppic to bbox pic;
+    tmppic
+  endgroup
+enddef;
+
+def junction(expr txt, z ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := nullpicture;
+    addto tmppic also shiftoff( txt scaled textscale, to_center );
+    setbounds tmppic to (-smallblockr,-smallblockr)--(-smallblockr,smallblockr)--(smallblockr,smallblockr)--(smallblockr,-smallblockr)--cycle;
+    tmppic := tmppic shifted z;
+    if junctionimplicitdraw:
+      draw tmppic;
+    fi
+    tmppic
+  endgroup
+enddef;
+
+
+def junctionlbl(expr txt, arrowdir, lbl, z, arrow ) =
+  begingroup
+    save tmppic, ahlength, p, d;
+    ahlength := 1mm;
+    path p;
+    numeric d;
+    picture tmppic;
+    tmppic := nullpicture;
+    addto tmppic also shiftoff( txt scaled textscale, to_center );
+
+    if arrowdir = to_top:
+      p := ((lrcorner tmppic)--(urcorner tmppic)) shifted ( z + (connectionlw + 2*ahlength*sind(0.5*ahangle),0) );
+      d = to_rt;
+    elseif arrowdir = to_lft:
+      p := ((urcorner tmppic)--(ulcorner tmppic)) shifted ( z + (0,connectionlw + 2*ahlength*sind(0.5*ahangle)) );
+      d = to_top;
+    elseif arrowdir = to_bot:
+      p := ((urcorner tmppic)--(lrcorner tmppic)) shifted ( z + (connectionlw + 2*ahlength*sind(0.5*ahangle),0) );
+      d = to_rt;
+    elseif arrowdir = to_rt:
+      p := ((ulcorner tmppic)--(urcorner tmppic)) shifted ( z + (0,connectionlw + 2*ahlength*sind(0.5*ahangle)) );
+      d = to_top;
+    fi
+
+    setbounds tmppic to (-smallblockr,-smallblockr)--(-smallblockr,smallblockr)--(smallblockr,smallblockr)--(smallblockr,-smallblockr)--cycle;
+    tmppic := tmppic shifted z;
+
+    if junctionimplicitdraw:
+      if arrow:
+	drawarrow p withpen pencircle scaled connectionlw;
+      fi
+      draw conlabel( d, lbl, mspoint( p, 0.5, 0 ) );
+      draw tmppic;
+    fi
+    tmppic
+  endgroup
+enddef;
+
+def terminal(expr d, txt, z ) =
+  begingroup
+    save tmppic;
+    picture tmppic;
+    tmppic := shiftoff( withbbmargin( txt scaled textscale ), d ) shifted ( z - smallblockr * dir_to( d ) );
+    if junctionimplicitdraw:
+      draw tmppic;
+    fi
+    tmppic
+  endgroup  
+enddef;
+
+def ignorepicture(expr pic ) =
+  show 0
+enddef;
+
+def terminalto(expr j, txt, z ) =
+  begingroup
+    ignorepicture( terminal( to_dir( z - (center j) ), txt, z ) );
+    bgconnect( pointpicture( z ) , j )
+  endgroup
+enddef;
+
+def terminalfr(expr j, txt, z ) =
+  begingroup
+    ignorepicture( terminal( to_dir( z - (center j) ), txt, z ) );
+    bgconnect( j, pointpicture( z ) )
+  endgroup
+enddef;
+
+def bgconnect(expr pica, picb ) =
+  begingroup
+    save d;
+    pair d;
+    if (center pica) = (center picb):
+      d := (1,0);
+    else:
+      d := unitvector( (center picb) - (center pica) );
+    fi
+    ((center pica)+d*smallblockr)--((center picb)-d*smallblockr)
+  endgroup
+enddef;
+
+def bond(expr p ) =
+  begingroup
+    save t;
+    numeric t;
+    t := arctime arclength(p) - ahlength of p;
+    save z;
+    pair z;
+    z = (point t of p) + dir(angle(direction t of p)+90) * ahlength*sind(0.5*ahangle);
+    save res;
+    path res;
+    if useopenbonds:
+      draw p--z withpen pencircle scaled connectionlw
+    else:
+      draw p withpen pencircle scaled connectionlw;
+      res = (subpath (t,infinity) of p)--z--cycle;
+      filldraw res withpen pencircle scaled connectionlw
+    fi
+  endgroup
+enddef;
+
+def causalmark(expr p, where ) =
+  begingroup
+    save d;
+    numeric d;
+    d = angle( direction where of p );
+    if where = 0:
+      d := d + 180;
+    fi
+    save z;
+    pair z;
+    z = ( point where of p ) + dir(d) * connectionlw;
+    save res;
+    path res;
+    res = (z+dir(d+90)*ahlength*sind(0.5*ahangle))--(z+dir(d-90)*ahlength*sind(0.5*ahangle));
+    draw res withpen pencircle scaled (2*connectionlw)
+  endgroup
+enddef;
+
+def hbond(expr p ) =
+  begingroup
+    bond( p );
+    causalmark( p, infinity )
+  endgroup
+enddef;
+
+def tbond(expr p ) =
+  begingroup
+    bond( p );
+    causalmark( p, 0 )
+  endgroup
+enddef;
+
+def flowlabel(expr p, txt ) =
+%  the midpoint has typically singular direction, so we can't do the obvious:
+%  draw( conlabel( to_dir( dir( angle( direction (0.5*length(p)) of p ) - 90 ) ), txt, mspoint( p, 0.5, 0 ) ) )
+  draw conlabel( to_dir( dir( angle( (point infinity of p) - (point 0 of p) ) - 90 ) ), txt, mspoint( p, 0.5, 0 ) ) withpen pencircle scaled connectionlw
+enddef;
+
+def effortlabel(expr p, txt ) =
+%  the midpoint has typically singular direction, so we can't do the obvious:
+%  draw( conlabel( to_dir( dir( angle( direction (0.5*length(p)) of p ) + 90 ) ), txt, mspoint( p, 0.5, 0 ) ) )
+  draw conlabel( to_dir( dir( angle( (point infinity of p) - (point 0 of p) ) + 90 ) ), txt, mspoint( p, 0.5, 0 ) ) withpen pencircle scaled connectionlw
+enddef;
diff --git a/Master/texmf-dist/metapost/blockdraw_mp/cascadedemo.mp b/Master/texmf-dist/metapost/blockdraw_mp/cascadedemo.mp
new file mode 100644
index 00000000000..26c919bb83a
--- /dev/null
+++ b/Master/texmf-dist/metapost/blockdraw_mp/cascadedemo.mp
@@ -0,0 +1,73 @@
+verbatimtex
+%& latex
+\documentclass[a4]{article}
+\begin{document}
+etex
+
+input blockdraw;
+input ./docblockprefs;
+
+
+beginfig( -1 )
+
+  % The controller box has corners (x1,y1), (x2,y2)
+  % The inner system box has corners (x3,y3), (x4,y4)
+  y1 := -2u;
+  y2 := 1.3u;
+  y3 := -1.4u;
+  y4 := 1u;
+  
+  picture reg[];
+  reg1 := longblock( btex Reg.~1 etex, (-1u,0) );
+  reg2 := longblock( btex Reg.~2 etex, (-4u,0) );
+
+  picture G[];
+  G1 := longblock( btex $G_{1}$ etex, (1.5u,0) );
+  G2 := longblock( btex $G_{2}$ etex, (4u,0) );
+
+  picture terminator[];
+  terminator1 := pointpicture( leftpoint( reg2, 2, 2 ) - (1u,0) );
+  terminator2 := pointpicture( (5.5u,0) );
+
+  path con;
+  picture lab;
+  
+  con := hhconnect( center( terminator1 ), leftpoint( reg2, 2, 2 ), 0.5, 0 );
+  lab := conlabel( to_ulft, btex $y_{\mathrm{ref}}$ etex, point infinity of con );
+  x1 := xpart( mspoint( con, 0.2, 0 ) );
+  
+  con := hhconnect( rightpoint( reg2, 2, 2 ), leftpoint( reg1, 2, 2 ), 0.5, 0 );
+  lab := conlabel( to_urt, btex $z_{\mathrm{ref}}$ etex, point 0 of con );
+  x3 := xpart( mspoint( con, 0.6, 0 ) );
+  
+  con := rlconnect( reg1, G1 );
+  lab := conlabel( to_top, btex $u$ etex, mspoint( con, 0.8, 0 ) );
+  x2 := xpart( mspoint( con, 0.3, 0 ) );
+
+  picture split[];  
+
+  con := rlconnect( G1, G2 );
+  lab := conlabel( to_top, btex $z$ etex, mspoint( con, 0.8, 0 ) );
+  split1 := splitdot( mspoint( con, 0.3, 0 ) );
+  x4 := xpart( mspoint( con, 0.5, 0 ) );
+
+  con := rlconnect( G2, terminator2 );
+  lab := conlabel( to_top, btex $y$ etex, mspoint( con, 0.8, 0 ) );
+  split2 := splitdot( mspoint( con, 0.4, 0 ) );
+
+  % Draw boxes
+  draw (x1,y1)--(x1,y2)--(x2,y2)--(x2,y1)--cycle withpen pencircle scaled dashlw dashed gldash1;
+  draw (x3,y3)--(x3,y4)--(x4,y4)--(x4,y3)--cycle withpen pencircle scaled dashlw dashed gldash2;
+
+  % Draw broken connections
+  pair p;
+  p := ( x2, 0.5[y1,y3] );
+  con := vhconnect( center split2, p );
+  con := hhconnect( p, leftpoint( reg2, 2, 1 ), 1, 0.4u );
+
+  p := ( x2, 1.5[y1,y3] );
+  con := vhconnect( center split1, p );
+  con := hhconnect( p, leftpoint( reg1, 2, 1 ), 1, 0.4u );
+
+endfig;
+end;
diff --git a/Master/texmf-dist/metapost/blockdraw_mp/docblockprefs.mp b/Master/texmf-dist/metapost/blockdraw_mp/docblockprefs.mp
new file mode 100644
index 00000000000..1aa63c0f01e
--- /dev/null
+++ b/Master/texmf-dist/metapost/blockdraw_mp/docblockprefs.mp
@@ -0,0 +1,18 @@
+numeric u;
+u := 1cm;
+
+numeric dashlw;
+dashlw := 0.3pt;
+picture gldash[];
+gldash1 := dashpattern( on 0.25u off 0.25u );
+gldash2 := dashpattern( on 0.5u off 0.1u on 0.1u off 0.1u on 0.1u off 0.1u );
+
+longblockrx := 0.7u;
+longblockry := 0.4u;
+smallblockr := 0.3u;
+connectionlw := 0.8pt;
+textscale := 1;
+
+shiftofflabelmargin := 2bboxmargin;
+pickup pencircle scaled connectionlw;
+
diff --git a/Master/texmf-dist/metapost/blockdraw_mp/shiftoff.mp b/Master/texmf-dist/metapost/blockdraw_mp/shiftoff.mp
new file mode 100644
index 00000000000..b5ad73f834c
--- /dev/null
+++ b/Master/texmf-dist/metapost/blockdraw_mp/shiftoff.mp
@@ -0,0 +1,130 @@
+%% shiftoff.mp
+%% Copyright 2006 Henrik Tidefelt
+% 
+% This work may be distributed and/or modified under the 
+% conditions of the LaTeX Project Public License, either version 1.3 
+% of this license or (at your option) any later version.
+% The latest version of this license is in 
+% http://www.latex-project.org/lppl.txt 
+% and version 1.3 or later is part of all distributions of LaTeX 
+% version 2005/12/01 or later.
+% 
+% This work has the LPPL maintenance status `maintained´.
+% 
+% The Current Maintainer of this work is Henrik Tidefelt,
+% tidefelt@isy.liu.se.
+% 
+% This work, referred to as blockdraw.mp, consists of the files
+%   shiftoff.mp
+%   blockdraw.mp
+%   bondgraph.mp
+%   blockdraw_mp.pdf
+
+numeric to_lft;
+to_lft = 0;
+numeric to_llft;
+to_llft = 1;
+numeric to_bot;
+to_bot = 2;
+numeric to_lrt;
+to_lrt = 3;
+numeric to_rt;
+to_rt = 4;
+numeric to_urt;
+to_urt = 5;
+numeric to_top;
+to_top = 6;
+numeric to_ulft;
+to_ulft = 7;
+numeric to_center;
+to_center = 8;
+
+def to_dir(expr z ) =
+  if (xpart z) > 0:
+    if (ypart z) > 0:
+      if abs(xpart z) > 2*abs(ypart z):
+	to_rt
+      elseif abs(ypart z) > 2*abs(xpart z):
+	to_top
+      else:
+	to_urt
+      fi
+    else:
+      if abs(xpart z) > 2*abs(ypart z):
+	to_rt
+      elseif abs(ypart z) > 2*abs(xpart z):
+	to_bot
+      else:
+	to_lrt
+      fi
+    fi
+  else:
+    if (ypart z) > 0:
+      if abs(xpart z) > 2*abs(ypart z):
+	to_lft
+      elseif abs(ypart z) > 2*abs(xpart z):
+	to_top
+      else:
+	to_ulft
+      fi
+    else:
+      if abs(xpart z) > 2*abs(ypart z):
+	to_lft
+      elseif abs(ypart z) > 2*abs(xpart z):
+	to_bot
+      else:
+	to_llft
+      fi
+    fi
+  fi
+enddef;
+
+def dir_to(expr d ) =
+  dir( 180 + d * 45 )
+enddef;
+
+def shiftoff(expr pic, corner ) =
+  if corner = to_lft:
+    (pic shifted ((-center pic)+((xpart llcorner pic)-(xpart center pic),0)))
+  elseif corner = to_llft:
+    (pic shifted ((-center pic)+(llcorner pic)-(center pic)))
+  elseif corner = to_bot:
+    (pic shifted ((-center pic)+(0,(ypart llcorner pic)-(ypart center pic))))
+  elseif corner = to_lrt:
+    (pic shifted ((-center pic)+(lrcorner pic)-(center pic)))
+  elseif corner = to_rt:
+    (pic shifted ((-center pic)+((xpart lrcorner pic)-(xpart center pic),0)))
+  elseif corner = to_urt:
+    (pic shifted ((-center pic)+(urcorner pic)-(center pic)))
+  elseif corner = to_top:
+    (pic shifted ((-center pic)+(0,(ypart ulcorner pic)-(ypart center pic))))
+  elseif corner = to_ulft:
+    (pic shifted ((-center pic)+(ulcorner pic)-(center pic)))
+  else:
+    (pic shifted (-center pic))
+  fi
+enddef;
+
+numeric shiftofflabelmargin;
+shiftofflabelmargin := bboxmargin;
+def shiftoffwlm(expr pic, corner ) =
+  if corner = to_lft:
+    (pic shifted ((-center pic)+((xpart llcorner pic)-(xpart center pic),0)+(-shiftofflabelmargin,0)))
+  elseif corner = to_llft:
+    (pic shifted ((-center pic)+(llcorner pic)-(center pic)+(-shiftofflabelmargin,-shiftofflabelmargin)))
+  elseif corner = to_bot:
+    (pic shifted ((-center pic)+(0,(ypart llcorner pic)-(ypart center pic))+(0,-shiftofflabelmargin)))
+  elseif corner = to_lrt:
+    (pic shifted ((-center pic)+(lrcorner pic)-(center pic)+(shiftofflabelmargin,-shiftofflabelmargin)))
+  elseif corner = to_rt:
+    (pic shifted ((-center pic)+((xpart lrcorner pic)-(xpart center pic),0)+(shiftofflabelmargin,0)))
+  elseif corner = to_urt:
+    (pic shifted ((-center pic)+(urcorner pic)-(center pic)+(shiftofflabelmargin,shiftofflabelmargin)))
+  elseif corner = to_top:
+    (pic shifted ((-center pic)+(0,(ypart ulcorner pic)-(ypart center pic))+(0,shiftofflabelmargin)))
+  elseif corner = to_ulft:
+    (pic shifted ((-center pic)+(ulcorner pic)-(center pic)+(-shiftofflabelmargin,shiftofflabelmargin)))
+  else:
+    (pic shifted (-center pic))
+  fi
+enddef;