Initial revision

Demo/sgi/gl/kites.py

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+#! /usr/local/python
+
+# *** This only works correctly on a 24 bit-plane machine. ***
+#
+# A simple Python program that tests the some parts of the
+# GL library. It shows the speed that can be obtained when
+# doing simple graphics.
+#
+# The bottleneck in this program is NOT Python but the graphics
+# engine; i.e Python can feed the graphics pipeline fast enough
+# on the 4D/25G.
+#
+# This program show 3 kites flying around the screen. It uses
+#
+# 	* bgnpolygon, endpolygon
+# 	* v3, n3
+# 	* lmdef, lmbind
+#
+# Usage :
+# 
+# 	ESC 	-> exit program
+# 	MOUSE3 	-> freeze toggle
+# 	MOUSE2 	-> one step (use this in freeze state)
+
+from GL import *
+from gl import *
+import DEVICE
+from math import *
+
+#
+# viewobj : sets the rotation, translation and scaling
+# set appropiate material, call drawobject()
+#
+def viewobj (r, s, t, mat) :
+	pushmatrix()
+	rot (r * 10.0, 'X')
+	rot (r * 10.0, 'Y')
+	rot (r * 10.0, 'Z')
+	scale (s[0], s[1], s[2])
+	translate (t[0], t[1], t[2])
+	lmbind(MATERIAL, mat)
+	drawobject()
+	popmatrix()
+
+#
+# makeobj : the contructor of the object
+#
+def mkobj () :
+	v0 = (-5.0 ,0.0, 0.0)
+	v1 = (0.0 ,5.0, 0.0)
+	v2 = (5.0 ,0.0, 0.0)
+	v3 = (0.0 ,2.0, 0.0)
+	n0 = (sqrt(2.0)/2.0, sqrt(2.0)/2.0, 0.0)
+	vn = ((v0, n0), (v1, n0), (v2, n0), (v3, n0))
+	#
+	return vn
+
+#
+# the object itself as an array of vertices and normals
+#
+kite = mkobj ()
+
+#
+# drawobject : draw a triangle. with bgnpolygon
+#
+def drawobject () :
+	#
+	bgnpolygon()
+	vnarray (kite)
+	endpolygon()
+
+#
+# identity matrix
+#
+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]
+
+#
+# the rgb-value of light-blue 
+#
+LightBlue = (43,169,255)
+
+#
+# the different materials.
+#
+m1=[SPECULAR,0.0,0.0,0.6,DIFFUSE,0.0,0.0,0.8,SHININESS,20.0,LMNULL]
+m2=[SPECULAR,0.8,0.0,0.1,DIFFUSE,0.8,0.0,0.3,SHININESS,120.0,LMNULL]
+m3=[SPECULAR,0.0,1.0,0.0,DIFFUSE,0.0,0.6,0.0,SHININESS,120.0,LMNULL]
+
+#
+# lightsources
+#
+light1 = [LCOLOR,1.0,1.0,1.0,POSITION,15.0,15.0,0.0,1.0,LMNULL]
+light2 = [LCOLOR,1.0,1.0,1.0,POSITION,-15.0,15.0,0.0,1.0,LMNULL]
+
+#
+# the lightmodel
+#
+model = [AMBIENT,0.2,0.2,0.2,LMNULL]
+
+#
+# initgl : opens the window, configures the pipeline to 2buf and zbuf,
+# sets the viewing, defines and binds the materials
+#
+def initgl () :
+	#
+	# open window
+	#
+	foreground ()
+	keepaspect (1, 1)
+	prefposition (100, 500, 100, 500)
+	w = winopen ('PYTHON lights')
+	keepaspect (1, 1)
+	winconstraints()
+	#
+	# configure pipeline (zbuf, 2buf, GOURAUD and RGBmode)
+	#
+	zbuffer (1)
+	doublebuffer ()
+	shademodel (GOURAUD)
+	RGBmode ()
+	gconfig ()
+	#
+	# define and bind materials (set perspective BEFORE loadmat !)
+	#
+	mmode(MVIEWING)
+	perspective (900, 1.0, 1.0, 20.0)
+	loadmatrix(idmat)
+	lmdef(DEFMATERIAL, 1, m1)
+	lmdef(DEFMATERIAL, 2, m2)
+	lmdef(DEFMATERIAL, 3, m3)
+	lmdef(DEFLIGHT, 1, light1)
+	lmdef(DEFLIGHT, 2, light2)
+	lmdef(DEFLMODEL, 1, model)
+	lmbind(LIGHT0,1)
+	lmbind(LIGHT1,2)
+	lmbind(LMODEL,1)
+	#
+	# set viewing
+	#
+	lookat (0.0, 0.0, 10.0, 0.0, 0.0, 0.0, 0)
+	#
+	# ask for the REDRAW and ESCKEY events
+	#
+	qdevice(DEVICE.MOUSE3)
+	qdevice(DEVICE.MOUSE2)
+	qdevice(DEVICE.REDRAW)
+	qdevice(DEVICE.ESCKEY)
+
+#
+# GoForIT : use 2buf to redraw the object 2n times. index i is used as 
+# the (smoothly changing) rotation angle
+#
+def GoForIt(i) :
+	freeze = 1
+	while 1 :
+		if freeze <> 0 :
+			i = i + 1
+		#
+		# clear z-buffer and clear background to light-blue
+		#
+		zclear()
+		c3i (LightBlue)
+		clear()
+		#
+		# draw the 3 traiangles scaled above each other.
+		#
+		viewobj(float(i),[1.0,1.0,1.0],[1.0,1.0,1.0],1)
+		viewobj(float(i),[0.75,0.75,0.75],[0.0,2.0,2.0],2)
+		viewobj(float(i),[0.5,0.5,0.5],[0.0,4.0,4.0],3)
+		#
+		swapbuffers()
+		#
+		if qtest() <> 0 :
+			dev, val = qread()
+			if dev == DEVICE.ESCKEY :
+				break
+			elif dev == DEVICE.REDRAW :
+				reshapeviewport ()
+			elif dev == DEVICE.MOUSE3 and val <> 0 :
+				freeze = 1 - freeze
+			elif dev == DEVICE.MOUSE2 and val <> 0 :
+				i = i + 1
+
+
+# the main program
+#
+def main () :
+	initgl ()
+	GoForIt (0)
+
+#
+# exec main
+#
+main  ()