Initial revision
diff --git a/Demo/sgi/gl/zrgb.py b/Demo/sgi/gl/zrgb.py
new file mode 100755
index 0000000..fa01840
--- /dev/null
+++ b/Demo/sgi/gl/zrgb.py
@@ -0,0 +1,168 @@
+#! /usr/local/python
+
+# zrgb (Requires Z buffer.)
+#
+# This program demostrates zbuffering 3 intersecting RGB polygons while
+# in doublebuffer mode where, movement of the mouse with the LEFTMOUSE
+# button depressed will, rotate the 3 polygons. This is done by compound
+# rotations allowing continuous screen-oriented rotations.
+#
+# Press the "Esc" key to exit.
+
+from gl import *
+from GL import *
+from DEVICE import *
+
+
+idmat=[1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1]
+
+def main() :
+ #
+ # old and new mouse position
+ #
+ #
+ mode = 0
+ omx = 0
+ mx = 0
+ omy = 0
+ my = 0
+ #
+ objmat=[1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1]
+ #
+ initialize ()
+ #
+ draw_scene (objmat)
+ #
+ while (1) :
+ #
+ dev, val = qread()
+ #
+ if dev == ESCKEY :
+ if val :
+ break
+ # exit when key is going up, not down
+ # this avoids the scenario where a window
+ # underneath this program's window
+ # would otherwise "eat up" the up-
+ # event of the Esc key being released
+ return
+ #
+ elif dev == REDRAW :
+ reshapeviewport()
+ draw_scene(objmat)
+ #
+ elif dev == LEFTMOUSE:
+ omx = mx
+ omy = my
+ if val :
+ mode = 1
+ else :
+ mode = 0
+ elif dev == MOUSEX :
+ omx = mx
+ mx = val
+ #print omx, mx
+ objmat = update_scene(objmat,mx,my,omx,omy,mode)
+ #
+ elif dev == MOUSEY :
+ omy = my
+ my = val
+ #print omy, my
+ objmat = update_scene(objmat,mx,my,omx,omy,mode)
+ #
+
+
+def initialize () :
+ #
+ foreground ()
+ keepaspect(5, 4)
+ w = winopen('Zbuffered RGB')
+ #
+ doublebuffer()
+ RGBmode()
+ gconfig()
+ zbuffer(1)
+ lsetdepth(0x0, 0x7FFFFF)
+ #
+ qdevice(ESCKEY)
+ qdevice(LEFTMOUSE)
+ qdevice(MOUSEX)
+ qdevice(MOUSEY)
+
+def update_scene (mat, mx, my, omx, omy, mode) :
+ #
+ if mode == 1 :
+ mat = orient(mat, mx, my, omx, omy)
+ draw_scene(mat)
+ return mat
+
+def orient (mat, mx, my, omx, omy) :
+ #
+ #
+ pushmatrix()
+ loadmatrix(idmat)
+ #
+ if mx - omx : rot (float (mx - omx), 'y')
+ if omy - my : rot (float (omy - my), 'x')
+ #
+ multmatrix(mat)
+ mat = getmatrix()
+ #
+ popmatrix()
+ #
+ return mat
+
+def draw_scene (mat) :
+ RGBcolor(40, 100, 200)
+ clear()
+ zclear()
+ #
+ perspective(400, 1.25, 30.0, 60.0)
+ translate(0.0, 0.0, -40.0)
+ multmatrix(mat)
+ #
+ # skews original view to show all polygons
+ #
+ rotate(-580, 'y')
+ draw_polys()
+ #
+ swapbuffers()
+
+polygon1 = [(-10.0,-10.0,0.0),(10.0,-10.0,0.0),(-10.0,10.0,0.0)]
+
+polygon2 = [(0.0,-10.0,-10.0),(0.0,-10.0,10.0),(0.0,5.0,-10.0)]
+
+polygon3 = [(-10.0,6.0,4.0),(-10.0,3.0,4.0),(4.0,-9.0,-10.0),(4.0,-6.0,-10.0)]
+
+def draw_polys():
+ bgnpolygon()
+ cpack(0x0)
+ v3f(polygon1[0])
+ cpack(0x007F7F7F)
+ v3f(polygon1[1])
+ cpack(0x00FFFFFF)
+ v3f(polygon1[2])
+ endpolygon()
+ #
+ bgnpolygon()
+ cpack(0x0000FFFF)
+ v3f(polygon2[0])
+ cpack(0x007FFF00)
+ v3f(polygon2[1])
+ cpack(0x00FF0000)
+ v3f(polygon2[2])
+ endpolygon()
+ #
+ bgnpolygon()
+ cpack(0x0000FFFF)
+ v3f(polygon3[0])
+ cpack(0x00FF00FF)
+ v3f(polygon3[1])
+ cpack(0x00FF0000)
+ v3f(polygon3[2])
+ cpack(0x00FF00FF)
+ v3f(polygon3[3])
+ endpolygon()
+
+
+main ()