manual/connector.py

   1 #!/usr/bin/env python
   2 # -*- coding: ISO-8859-15 -*-
   3 import sys
   4 sys.path.insert(0, "..")
   5 from math import *
   6 from pyx import *
   7 try:
   8     from math import radians, degrees
   9 except ImportError:
  10     # fallback implementation for Python 2.1
  11     def radians(x): return x*pi/180
  12     def degrees(x): return x*180/pi
  13
  14 startbox = box.polygon(corners=[[0,-0.6], [0.5,0.1], [-0.25,0.1]])
  15 endbox = box.polygon(corners=[[4.5,3.9], [5.5,4.0], [5.2,3.4]])
  16
  17 # the arc connector <<<
  18 c1 = canvas.canvas()
  19 for b in [startbox, endbox]:
  20     c1.stroke(b.path(), [style.linewidth.Thick, style.linejoin.round])
  21     c1.fill(path.circle_pt(b.center[0], b.center[1], 2))
  22 absangle = degrees(atan2(endbox.center[1] - startbox.center[1], endbox.center[0] - startbox.center[0]))
  23 relangle = 60
  24 len = 2
  25
  26 # the direct connection
  27 direct = path.line_pt(startbox.center[0], startbox.center[1], endbox.center[0], endbox.center[1])
  28 c1.stroke(direct, [style.linestyle.dashed])
  29
  30 # the arc connector
  31 l = connector.arc(startbox, endbox, relangle=relangle, boxdists=[0.0,0.0])
  32 c1.stroke(l, [style.linewidth.Thick, color.rgb.red, deco.earrow.Large])
  33
  34 # the relangle parameter
  35 comp1 = path.path(path.moveto(*direct.atbegin()),
  36                   path.rlineto(len*cos(radians(absangle + relangle)), len*sin(radians(absangle + relangle))))
  37 c1.stroke(comp1)
  38 ang = path.path(path.arc(direct.atbegin()[0], direct.atbegin()[1], 0.8*len, absangle, absangle+relangle))
  39 c1.stroke(ang, [deco.earrow.large])
  40 pos = ang.at(0.5*ang.arclen())
  41 c1.text(pos[0], pos[1], r"~relangle", [text.halign.left])
  42
  43 # the bulge parameter
  44 bulge = 0.5 * direct.arclen() * tan(0.5*radians(relangle))
  45 bul = path.path(path.moveto(*direct.at(0.5*direct.arclen())),
  46                 path.rlineto(bulge * cos(radians(absangle+90)), bulge * sin(radians(absangle+90))))
  47 c1.stroke(bul, [deco.earrow.large])
  48 pos = bul.at(0.5*bul.arclen())
  49 c1.text(pos[0], pos[1], r"~(rel)bulge", [text.halign.left])
  50
  51 # >>>
  52
  53 # the curve connector <<<
  54 c2 = canvas.canvas()
  55 for b in [startbox, endbox]:
  56     c2.stroke(b.path(), [style.linewidth.Thick, style.linejoin.round])
  57     c2.fill(path.circle_pt(b.center[0], b.center[1], 2))
  58 absangle = degrees(atan2(endbox.center[1] - startbox.center[1], endbox.center[0] - startbox.center[0]))
  59 relangle1 = 60
  60 relangle2 = 30
  61 absbulge = 0
  62 relbulge = 0.5
  63 len = 2
  64
  65 # the direct connection
  66 direct = path.line_pt(startbox.center[0], startbox.center[1], endbox.center[0], endbox.center[1])
  67 c2.stroke(direct, [style.linestyle.dashed])
  68
  69 # the arc connector
  70 l = connector.curve(startbox, endbox, relangle1=relangle1, relangle2=relangle2, absbulge=absbulge, relbulge=relbulge, boxdists=[0.0,0.0])
  71 #l = connector.curve(startbox, endbox, absangle1=absangle+relangle1, absangle2=absangle+relangle2, absbulge=absbulge, relbulge=relbulge, boxdists=[0.0,0.0])
  72 c2.stroke(l, [style.linewidth.Thick, color.rgb.red, deco.earrow.Large])
  73
  74 # the relangle parameters
  75 # relangle1
  76 c2.stroke(path.path(path.moveto(*direct.atbegin()),
  77                    path.rlineto(len*cos(radians(absangle + relangle1)),
  78                                 len*sin(radians(absangle + relangle1)))))
  79 ang = path.path(path.arc(direct.atbegin()[0], direct.atbegin()[1], 0.8*len, absangle, absangle+relangle1))
  80 c2.stroke(ang, [deco.earrow.large])
  81 pos = ang.at(0.5*ang.arclen())
  82 c2.text(pos[0], pos[1], r"~relangle1", [text.halign.left])
  83
  84 # absangle1
  85 c2.stroke(path.path(path.moveto(*direct.atbegin()), path.rlineto(len, 0)))
  86 ang = path.path(path.arc(direct.atbegin()[0], direct.atbegin()[1], 0.5*len, 0, absangle+relangle1))
  87 c2.stroke(ang, [deco.earrow.large])
  88 pos = ang.at(0.2*ang.arclen())
  89 c2.text(pos[0], pos[1], r"~absangle1", [text.halign.left])
  90
  91 # relangle2
  92 c2.stroke(path.path(path.moveto(*direct.atend()),
  93                    path.rlineto(len*cos(radians(absangle)),
  94                                 len*sin(radians(absangle)))))
  95 c2.stroke(path.path(path.moveto(*direct.atend()),
  96                    path.rlineto(len*cos(radians(absangle + relangle2)),
  97                                 len*sin(radians(absangle + relangle2)))))
  98 ang = path.path(path.arc(direct.atend()[0], direct.atend()[1],
  99                          0.8*len, absangle, absangle+relangle2))
 100 c2.stroke(ang, [deco.earrow.large])
 101 pos = ang.at(0.5*ang.arclen())
 102 c2.text(pos[0], pos[1], r"~relangle2", [text.halign.left])
 103
 104 # the bulge parameter
 105 bulge = absbulge + direct.arclen() * relbulge
 106 bul = path.path(path.moveto(*direct.atbegin()),
 107                 path.rlineto(bulge * cos(radians(absangle+relangle1)), bulge * sin(radians(absangle+relangle1))))
 108 c2.stroke(bul, [deco.earrow.large])
 109 pos = bul.at(0.7*bul.arclen())
 110 c2.text(pos[0], pos[1], r"~(rel)bulge", [text.halign.left])
 111
 112 bul = path.path(path.moveto(*direct.atend()),
 113                 path.rlineto(-bulge * cos(radians(absangle+relangle2)), -bulge * sin(radians(absangle+relangle2))))
 114 c2.stroke(bul, [deco.earrow.large])
 115 pos = bul.at(0.7*bul.arclen())
 116 c2.text(pos[0], pos[1], r"~(rel)bulge", [text.halign.left, text.vshift(1)])
 117 # >>>
 118
 119
 120 # write everything
 121 c1.insert(c2, [trafo.translate(6.5, 0)])
 122 c1.writePDFfile()
 123
 124 # vim:foldmethod=marker:foldmarker=<<<,>>>