Demo/sgi/gl/kites.py

   1 #! /usr/bin/env python
   2
   3 # *** This only works correctly on a 24 bit-plane machine. ***
   4 #
   5 # A simple Python program that tests the some parts of the
   6 # GL library. It shows the speed that can be obtained when
   7 # doing simple graphics.
   8 #
   9 # The bottleneck in this program is NOT Python but the graphics
  10 # engine; i.e Python can feed the graphics pipeline fast enough
  11 # on the 4D/25G.
  12 #
  13 # This program show 3 kites flying around the screen. It uses
  14 #
  15 #       * bgnpolygon, endpolygon
  16 #       * v3, n3
  17 #       * lmdef, lmbind
  18 #
  19 # Usage :
  20 #
  21 #       ESC     -> exit program
  22 #       MOUSE3  -> freeze toggle
  23 #       MOUSE2  -> one step (use this in freeze state)
  24
  25 from GL import *
  26 from gl import *
  27 import DEVICE
  28 from math import *
  29
  30 #
  31 # viewobj : sets the rotation, translation and scaling
  32 # set appropiate material, call drawobject()
  33 #
  34 def viewobj (r, s, t, mat) :
  35         pushmatrix()
  36         rot (r * 10.0, 'X')
  37         rot (r * 10.0, 'Y')
  38         rot (r * 10.0, 'Z')
  39         scale (s[0], s[1], s[2])
  40         translate (t[0], t[1], t[2])
  41         lmbind(MATERIAL, mat)
  42         drawobject()
  43         popmatrix()
  44
  45 #
  46 # makeobj : the constructor of the object
  47 #
  48 def mkobj () :
  49         v0 = (-5.0 ,0.0, 0.0)
  50         v1 = (0.0 ,5.0, 0.0)
  51         v2 = (5.0 ,0.0, 0.0)
  52         v3 = (0.0 ,2.0, 0.0)
  53         n0 = (sqrt(2.0)/2.0, sqrt(2.0)/2.0, 0.0)
  54         vn = ((v0, n0), (v1, n0), (v2, n0), (v3, n0))
  55         #
  56         return vn
  57
  58 #
  59 # the object itself as an array of vertices and normals
  60 #
  61 kite = mkobj ()
  62
  63 #
  64 # drawobject : draw a triangle. with bgnpolygon
  65 #
  66 def drawobject () :
  67         #
  68         bgnpolygon()
  69         vnarray (kite)
  70         endpolygon()
  71
  72 #
  73 # identity matrix
  74 #
  75 idmat=[1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0]
  76
  77 #
  78 # the rgb-value of light-blue
  79 #
  80 LightBlue = (43,169,255)
  81
  82 #
  83 # the different materials.
  84 #
  85 m1=[SPECULAR,0.0,0.0,0.6,DIFFUSE,0.0,0.0,0.8,SHININESS,20.0,LMNULL]
  86 m2=[SPECULAR,0.8,0.0,0.1,DIFFUSE,0.8,0.0,0.3,SHININESS,120.0,LMNULL]
  87 m3=[SPECULAR,0.0,1.0,0.0,DIFFUSE,0.0,0.6,0.0,SHININESS,120.0,LMNULL]
  88
  89 #
  90 # lightsources
  91 #
  92 light1 = [LCOLOR,1.0,1.0,1.0,POSITION,15.0,15.0,0.0,1.0,LMNULL]
  93 light2 = [LCOLOR,1.0,1.0,1.0,POSITION,-15.0,15.0,0.0,1.0,LMNULL]
  94
  95 #
  96 # the lightmodel
  97 #
  98 model = [AMBIENT,0.2,0.2,0.2,LMNULL]
  99
 100 #
 101 # initgl : opens the window, configures the pipeline to 2buf and zbuf,
 102 # sets the viewing, defines and binds the materials
 103 #
 104 def initgl () :
 105         #
 106         # open window
 107         #
 108         foreground ()
 109         keepaspect (1, 1)
 110         prefposition (100, 500, 100, 500)
 111         w = winopen ('PYTHON lights')
 112         keepaspect (1, 1)
 113         winconstraints()
 114         #
 115         # configure pipeline (zbuf, 2buf, GOURAUD and RGBmode)
 116         #
 117         zbuffer (1)
 118         doublebuffer ()
 119         shademodel (GOURAUD)
 120         RGBmode ()
 121         gconfig ()
 122         #
 123         # define and bind materials (set perspective BEFORE loadmat !)
 124         #
 125         mmode(MVIEWING)
 126         perspective (900, 1.0, 1.0, 20.0)
 127         loadmatrix(idmat)
 128         lmdef(DEFMATERIAL, 1, m1)
 129         lmdef(DEFMATERIAL, 2, m2)
 130         lmdef(DEFMATERIAL, 3, m3)
 131         lmdef(DEFLIGHT, 1, light1)
 132         lmdef(DEFLIGHT, 2, light2)
 133         lmdef(DEFLMODEL, 1, model)
 134         lmbind(LIGHT0,1)
 135         lmbind(LIGHT1,2)
 136         lmbind(LMODEL,1)
 137         #
 138         # set viewing
 139         #
 140         lookat (0.0, 0.0, 10.0, 0.0, 0.0, 0.0, 0)
 141         #
 142         # ask for the REDRAW and ESCKEY events
 143         #
 144         qdevice(DEVICE.MOUSE3)
 145         qdevice(DEVICE.MOUSE2)
 146         qdevice(DEVICE.REDRAW)
 147         qdevice(DEVICE.ESCKEY)
 148
 149 #
 150 # GoForIT : use 2buf to redraw the object 2n times. index i is used as
 151 # the (smoothly changing) rotation angle
 152 #
 153 def GoForIt(i) :
 154         freeze = 1
 155         while 1 :
 156                 if freeze <> 0 :
 157                         i = i + 1
 158                 #
 159                 # clear z-buffer and clear background to light-blue
 160                 #
 161                 zclear()
 162                 c3i (LightBlue)
 163                 clear()
 164                 #
 165                 # draw the 3 traiangles scaled above each other.
 166                 #
 167                 viewobj(float(i),[1.0,1.0,1.0],[1.0,1.0,1.0],1)
 168                 viewobj(float(i),[0.75,0.75,0.75],[0.0,2.0,2.0],2)
 169                 viewobj(float(i),[0.5,0.5,0.5],[0.0,4.0,4.0],3)
 170                 #
 171                 swapbuffers()
 172                 #
 173                 if qtest() <> 0 :
 174                         dev, val = qread()
 175                         if dev == DEVICE.ESCKEY :
 176                                 break
 177                         elif dev == DEVICE.REDRAW :
 178                                 reshapeviewport ()
 179                         elif dev == DEVICE.MOUSE3 and val <> 0 :
 180                                 freeze = 1 - freeze
 181                         elif dev == DEVICE.MOUSE2 and val <> 0 :
 182                                 i = i + 1
 183
 184
 185 # the main program
 186 #
 187 def main () :
 188         initgl ()
 189         GoForIt (0)
 190
 191 #
 192 # exec main
 193 #
 194 main  ()