Initial revision

1 files changed, 171 insertions, 0 deletions

diff --git a/Demo/sgi/gl/nurbs.py b/Demo/sgi/gl/nurbs.py
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+++ b/Demo/sgi/gl/nurbs.py
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+#! /usr/local/python
+
+# Rotate a 3D surface created using NURBS.
+#
+# Press left mouse button to toggle surface trimming.
+# Press ESC to quit.
+#
+# See the GL manual for an explanation of NURBS.
+
+from gl import *
+from GL import *
+from DEVICE import *
+
+TRUE = 1
+FALSE = 0
+ORDER = 4
+
+idmat = [1,0,0,0, 0,1,0,0, 0,0,1,0, 0,0,0,1]
+
+surfknots = [-1, -1, -1, -1, 1, 1, 1, 1]
+
+def make_ctlpoints():
+	c = []
+	#
+	ci = []
+	ci.append(-2.5,  -3.7,  1.0)
+	ci.append(-1.5,  -3.7,  3.0)
+	ci.append(1.5,  -3.7, -2.5)
+	ci.append(2.5,  -3.7,  -0.75)
+	c.append(ci)
+	#
+	ci = []
+	ci.append(-2.5,  -2.0,  3.0)
+	ci.append(-1.5,  -2.0,  4.0)
+	ci.append(1.5,  -2.0,  -3.0)
+	ci.append(2.5,  -2.0,  0.0)
+	c.append(ci)
+	#
+	ci = []
+	ci.append(-2.5, 2.0,  1.0)
+	ci.append(-1.5, 2.0,  0.0)
+	ci.append(1.5,  2.0,  -1.0)
+	ci.append(2.5,  2.0,  2.0)
+	c.append(ci)
+	#
+	ci = []
+	ci.append(-2.5,  2.7,  1.25)
+	ci.append(-1.5,  2.7,  0.1)
+	ci.append(1.5,  2.7,  -0.6)
+	ci.append(2.5,  2.7,  0.2)
+	c.append(ci)
+	#
+	return c
+
+ctlpoints = make_ctlpoints()
+
+trimknots = [0., 0., 0.,  1., 1.,  2., 2.,  3., 3.,   4., 4., 4.]
+
+def make_trimpoints():
+	c = []
+	c.append(1.0, 0.0, 1.0)
+	c.append(1.0, 1.0, 1.0)
+	c.append(0.0, 2.0, 2.0)
+	c.append(-1.0, 1.0, 1.0)
+	c.append(-1.0, 0.0, 1.0)
+	c.append(-1.0, -1.0, 1.0)
+	c.append(0.0, -2.0, 2.0)
+	c.append(1.0, -1.0, 1.0) 
+	c.append(1.0, 0.0, 1.0)
+	return c
+
+trimpoints = make_trimpoints()
+
+def main():
+	init_windows()
+	setup_queue()
+	make_lights()
+	init_view()
+	#
+	set_scene()
+	setnurbsproperty( N_ERRORCHECKING, 1.0 )
+	setnurbsproperty( N_PIXEL_TOLERANCE, 50.0 )
+	trim_flag = 0
+	draw_trim_surface(trim_flag)
+	#
+	while 1:
+		while qtest():
+			dev, val = qread()
+			if dev == ESCKEY:
+				return
+			elif dev == WINQUIT:
+				dglclose(-1)	# this for DGL only
+				return
+			elif dev == REDRAW:
+				reshapeviewport()
+				set_scene()
+				draw_trim_surface(trim_flag)
+			elif dev == LEFTMOUSE:
+				if val:
+					trim_flag = (not trim_flag)
+		set_scene()
+		draw_trim_surface(trim_flag)
+
+def init_windows():
+	foreground()
+	#prefposition(0, 500, 0, 500)
+	wid = winopen('nurbs')
+	wintitle('NURBS Surface')
+	doublebuffer()
+	RGBmode()
+	gconfig()
+	lsetdepth(0x000, 0x7fffff)
+	zbuffer( TRUE )
+
+def setup_queue():
+	qdevice(ESCKEY)
+	qdevice(REDRAW)
+	qdevice(RIGHTMOUSE)
+	qdevice(WINQUIT)
+	qdevice(LEFTMOUSE) #trimming
+
+def init_view():
+	mmode(MPROJECTION)
+	ortho( -4., 4., -4., 4., -4., 4. )
+	#
+	mmode(MVIEWING)
+	loadmatrix(idmat)
+	#
+	lmbind(MATERIAL, 1)
+
+def set_scene():
+	lmbind(MATERIAL, 0)
+	RGBcolor(150,150,150)
+	lmbind(MATERIAL, 1)
+	clear()
+	zclear()
+	#
+	rotate( 100, 'y' )
+	rotate( 100, 'z' )
+
+def draw_trim_surface(trim_flag):
+	bgnsurface()
+	nurbssurface(surfknots, surfknots, ctlpoints, ORDER, ORDER, N_XYZ)
+	if trim_flag:
+		bgntrim()
+		nurbscurve(trimknots, trimpoints, ORDER-1, N_STW)
+		endtrim()
+	endsurface()
+	swapbuffers()
+
+def make_lights():
+	lmdef(DEFLMODEL,1,[])
+	lmdef(DEFLIGHT,1,[])
+	#
+	# define material #1
+	#
+	a = []
+	a = a + [EMISSION, 0.0, 0.0, 0.0]
+	a = a + [AMBIENT,  0.1, 0.1, 0.1]
+	a = a + [DIFFUSE,  0.6, 0.3, 0.3]
+	a = a + [SPECULAR,  0.0, 0.6, 0.0]
+	a = a + [SHININESS, 2.0]
+	a = a + [LMNULL]
+	lmdef(DEFMATERIAL, 1, a)
+	#
+	# turn on lighting
+	#
+	lmbind(LIGHT0, 1)
+	lmbind(LMODEL, 1)
+
+main()