1 files changed, 100 insertions, 0 deletions
diff --git a/Master/texmf-dist/doc/metapost/featpost/example/standard/parafuso.mp b/Master/texmf-dist/doc/metapost/featpost/example/standard/parafuso.mp
new file mode 100644
index 00000000000..74e8cda3e77
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+++ b/Master/texmf-dist/doc/metapost/featpost/example/standard/parafuso.mp
@@ -0,0 +1,100 @@
+% parafuso.mp
+% L. Nobre G.
+% 2005
+
+%input featpost3Dplus2D;
+
+def theline( expr TheVal ) = 
+  begingroup
+    numeric par[], cred, cgre, cblu, param;
+    par0 = 0;
+    par1 = 6*360;
+    par2 = 0.3;
+    par3 = 850;
+    param = par0+TheVal*(par1-par0);
+    cred = -par2*cosd( param );
+    cblu = par2*sind( param );
+    cgre = param/par3;
+    ( (cred,cgre,cblu) )
+  endgroup 
+enddef;
+
+def loxodrome( expr TheVal ) = 
+  begingroup
+    numeric cred, cgre, cblu, alpha, theta, ratio, radio;
+    ratio = 22;
+    radio = 2;
+    theta = ratio*180*TheVal;
+    alpha = 170*TheVal-85;
+    cred = radio*cosd(theta)*cosd(alpha);
+    cgre = radio*sind(theta)*cosd(alpha);
+    cblu = radio*sind(alpha);
+    ( (cred,cgre,cblu) )
+  endgroup 
+enddef;
+
+f := (2,4,1.8);
+Spread := 77;
+ShadowOn := false;
+
+beginfig(1); 
+  numeric axsize, zaxpos, zaxlen;
+  color xbeg, xend, ybeg, yend, zbeg, zend;
+  axsize = 0.85;
+  zaxpos = 0.55;
+  zaxlen = 2.1;
+  pickup pencircle scaled 1.5pt;
+  xbeg = (axsize,0,0);
+  xend = (-axsize,0,0);
+  ybeg = (0,0,-axsize);
+  yend = (0,0,axsize);
+  zbeg = (zaxpos,-zaxpos,0);
+  zend = (zaxpos,zaxlen,0);
+  drawarrow rp( xbeg )--rp( xend );
+  drawarrow rp( ybeg )--rp( yend );
+%	defaultfont := "putr8r";
+  defaultscale := 1.95;
+  label.rt( "A", rp( xend ) );
+  label.lft( "B", rp( yend ) );
+  emptyline( false, 1, black, 0.5background, 1000, 0.82, 2, theline );
+  drawarrow rp( zbeg )--rp( zend );
+  label.bot( "C", rp( zend ) );
+endfig;
+
+beginfig(2); 
+  numeric axsize, zaxpos, zaxlen;
+  color xbeg, xend, ybeg, yend, zbeg, zend;
+  axsize = 0.85;
+  zaxpos = 0.55;
+  zaxlen = 2.1;
+  pickup pencircle scaled 1.5pt;
+  xbeg = (axsize,0,0);
+  xend = (-axsize,0,0);
+  ybeg = (0,0,-axsize);
+  yend = (0,0,axsize);
+  zbeg = (zaxpos,-zaxpos,0);
+  zend = (zaxpos,zaxlen,0);
+  drawarrow rp( xbeg )--rp( xend );
+  drawarrow rp( ybeg )--rp( yend );
+%	defaultfont := "putr8r";
+  defaultscale := 0.65;
+  label.rt( "X", rp( xend ) );
+  label.lft( "Y", rp( yend ) );
+  closedline( false, 70, 0.5, 0.95, theline );
+  drawarrow rp( zbeg )--rp( zend );
+  label.bot( "Z", rp( zend ) );
+  doitnow;
+endfig;
+
+f := (2,4,2.8);
+beginfig(3); 
+  NCL := 0;
+  Nobjects := 0;
+  closedline( false, 270, 0.5, 0.85, loxodrome );
+  doitnow;
+endfig;
+
+end;
+
+
+