Adding internal rotation function but gets strange result

Author: Tim Sheerman-Chase

README.md

@@ -29,13 +29,35 @@ Based on examples by Cyrille Rossant http://cyrille.rossant.net/shaders-opengl/
 <h2>Copying</h2>
 
 Copyright (c) 2012-2015, Tim Sheerman-Chase, Cyrille Rossant, Patrick Skjennum
+Copyright (c) 1995-2012, Michael C. Fletcher and Contributors
 All rights reserved.
 
-Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
-
-1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
-
-2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+	Redistributions of source code must retain the above copyright
+	notice, this list of conditions and the following disclaimer.
+
+	Redistributions in binary form must reproduce the above
+	copyright notice, this list of conditions and the following
+	disclaimer in the documentation and/or other materials
+	provided with the distribution.
+
+	The name of Michael C. Fletcher, or the name of any Contributor,
+	may not be used to endorse or promote products derived from this 
+	software without specific prior written permission.
+	
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+OF THE POSSIBILITY OF SUCH DAMAGE. 
 

transutils.py

@@ -0,0 +1,88 @@
+
+#Based on the PyVRML97 module, copyright (c) 1995-2012, Michael C. Fletcher and Contributors
+import math
+
+def rotMatrix(x, y, z, a):
+	"""Generate an opengl rotation matrix
+	x,y,z -- rotational vector axis
+	a -- angle in radians
+	"""
+	# normalize the rotation vector!
+	squared = x*x + y*y + z*z
+	if squared != 1.0:
+		length = squared ** .5
+		x /= squared 
+		y /= squared 
+		z /= squared
+	c = math.cos( a )
+	c1 = math.cos( -a )
+	s = math.sin( a )
+	s1 = math.sin( -a )
+	t = 1-c
+	R = [
+		[ t*x*x+c, t*x*y+s*z, t*x*z-s*y, 0.],
+		[ t*x*y-s*z, t*y*y+c, t*y*z+s*x, 0.],
+		[ t*x*z+s*y, t*y*z-s*x, t*z*z+c, 0.],
+		[ 0.,		0.,		0.,		 1.]
+	]
+	return R
+
+def scaleMatrix(x, y, z):
+	"""Generate scale matrix
+	x,y,z -- scale vector
+	"""
+	S = [ [x,0.,0.,0.], [0.,y,0.,0.], [0.,0.,z,0.], [0.,0.,0.,1.] ]
+	return S
+
+def transMatrix(x, y, z):
+	"""Generate translation matrix
+	x,y,z -- scale vector
+	"""
+	T = [ [1.,0.,0.,0.], [0.,1.,0.,0.], [0.,0.,1.,0.], [x,y,z,1] ]
+	return T
+
+def identityMatrix():
+	return [[1.,0.,0.,0.], [0.,1.,0.,0.], [0.,0.,1.,0.], [0.,0.,0.,1.]]
+
+if __name__ == "__main__":
+	#Check functions against opengl API
+	from OpenGL.GLUT import *
+	from OpenGL.GLUT.freeglut import *
+	import OpenGL.GL as gl
+	import numpy as np
+	import math
+
+	glutInit(sys.argv)
+	glutInitDisplayMode(GLUT_RGBA)
+	glutInitWindowSize(640, 480)
+	window = glutCreateWindow("Hello world!")
+
+	gl.glMatrixMode(gl.GL_MODELVIEW)
+	gl.glLoadIdentity()
+	mat = np.array(identityMatrix())
+
+	for i in range(10):
+
+		vec = list(100. * np.random.random((1,3))[0] - 50.)
+		gl.glTranslated(*vec)
+		correct = gl.glGetFloatv(gl.GL_MODELVIEW_MATRIX)
+		print "correct 1 ", correct
+
+		trans = np.array(transMatrix(*vec))
+		mat = np.dot(trans, mat)
+		print "predicted 1", mat
+		gl.glLoadMatrixf(list(mat.reshape(mat.size)))
+
+		#vec = list(4. * np.random.random((1,3))[0] - 2.)
+		vec = [1., 0., 0.]
+		ang = 4. * math.pi * np.random.random()
+		print vec, ang
+		gl.glRotated(vec[0], vec[1], vec[2], ang)
+		correct = gl.glGetFloatv(gl.GL_MODELVIEW_MATRIX)
+		print "correct 2", correct
+
+		trans = np.array(rotMatrix(vec[0], vec[1], vec[2], math.radians(ang)))
+		mat = np.dot(mat, trans)
+		print "predicted 2", mat
+		gl.glLoadMatrixf(list(mat.reshape(mat.size)))
+