import numpy
import PyQt4.Qt as qt

try:
	import OpenGL.GL  as GL
	import OpenGL.GLU as GLU
except ImportError:
	raise ImportError, "OpenGL must be installed to use these functionalities"


class MyGLWidget(qt.QGLWidget):
	def __init__(self, parent = None, crash = 0):
		qt.QGLWidget.__init__(self, parent)
		if crash:
			self._t = numpy.float64
		else:
			self._t = numpy.float32
		self.crash = crash
		self.generateData(512, 512)

	def generateData(self, xsize, ysize):
		self.xsize = xsize
		self.ysize = ysize
		self.vertices = numpy.zeros((xsize * ysize, 3), self._t)
		x = numpy.arange(xsize)
		y = numpy.arange(ysize)
		A=numpy.outer(x, numpy.ones(len(y), numpy.float32))
		B=numpy.outer(y, numpy.ones(len(x), numpy.float32))
		self.vertices[:,0]=A.flatten()
		self.vertices[:,1]=B.transpose().flatten()
		self.vertices[:,2]=range(xsize * ysize)
		self.vertexColors = numpy.zeros((xsize*ysize, 4), self._t)
		i = numpy.arange(len(self.vertices))
		self.vertexColors[:, 0] = (i & 255) / 255.
		self.vertexColors[:, 1] = ((i >> 8) & 255) / 255.
		self.vertexColors[:, 2] = ((i >> 16) & 255) / 255.
		self.vertexColors[:, 3] = 1.0

	def initializeGL(self):
		GL.glClearDepth(1.0)
		GL.glClearColor(0.5, 0.5, 0.5, 1.0)

		GL.glEnable(GL.GL_BLEND)
		GL.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA)

		GL.glShadeModel(GL.GL_FLAT)
		GL.glDisable(GL.GL_DITHER)
		GL.glMatrixMode(GL.GL_MODELVIEW)
		GL.glDisable(GL.GL_CULL_FACE)

	def resizeGL(self, width, height):
		GL.glViewport(0, 0, width, height)


		GL.glMatrixMode(GL.GL_PROJECTION)
		GL.glLoadIdentity()
		GL.glOrtho(0., 512., 0., 512., -self.xsize*self.ysize, self.xsize*self.ysize)
		GL.glMatrixMode(GL.GL_MODELVIEW)
		GL.glLoadIdentity()

		self.updateGL()


	def paintGL(self):
		GL.glClearColor(0.5, 0.5, 0.5, 1.0)
		GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT)
		GL.glMatrixMode(GL.GL_MODELVIEW)
		GL.glLoadIdentity()
		self.drawObject()

	def drawObject(self):
		GL.glVertexPointerf(self.vertices)
		if self.crash != 2:
			#import pdb; pdb.set_trace()
			GL.glColorPointerf(self.vertexColors)
		else:
			GL.glColorPointerd(self.vertexColors)
		GL.glEnableClientState(GL.GL_VERTEX_ARRAY)
		GL.glEnableClientState(GL.GL_COLOR_ARRAY)
		GL.glDrawArrays(GL.GL_POINTS, 0, self.xsize*self.ysize)
		GL.glDisableClientState(GL.GL_COLOR_ARRAY)
		GL.glDisableClientState(GL.GL_VERTEX_ARRAY)

if __name__ == "__main__":
	import sys
	if len(sys.argv) < 2:
		print "Usage:"
		print "python OpenGlTest.py 0 to get it going"
		print "python OpenGlTest.py 1 to get it crash"
		print "python OpenGlTest.py 2 to get it thru again using glColorPointerd"
		sys.exit(0)
	app = qt.QApplication(sys.argv)
	value = int(sys.argv[1])
	window = MyGLWidget(crash=value)
	window.show()
	app.exec_()