[PyOpenGL-Users] Problems with glReadPixels

[Dirk R. <di...@li...>]

	Hi everybody,

we're trying to use glReadPixels with PyOpenGL, but we're running into exceptions:

Traceback (most recent call last):
File "/store/home/mukaissi/MetNetVis/MetNetVis/UI/graphdrawwidget.py",
line 155, in mousePressEvent

index=GL.glReadPixels(event.x,event.y,1,1,GL.GL_RGB,GL.GL_UNSIGNED_BYTE)
File
"/store/home/mukaissi/software/PyOpenGL-3.0.0a6/OpenGL/GL/images.py", line
279, in glReadPixels
ctypes.c_void_p( arrayType.dataPointer(array))
ctypes.ArgumentError: argument 1: <type 'exceptions.TypeError'>: wrong
type

Adding a few prints to see the types of the involved variables they seem to
be ok:

array: [[[0 0 0]]] <type 'numpy.ndarray'>
arrayType: <class 'OpenGL.arrays.arraydatatype.GLubyteArray'> <type
'_ctypes.PointerType'>
dataPointer: 20509152 <type 'long'>

This is using 3.0.0a6 on an x86_64 (RHEL) system.

Is anybody using glReadPixels successfully? What are we missing?

Thanks

	Dirk