Invalid context for GL - PyOpenCL

25 May 2010

Hi,

I'm trying to access GL textures from pyopencl. Here is my test program:

import sys, os, pygame
from OpenGL.GL import *
sys.path.append("extern/pyopencl/build/lib.linux-x86_64-2.6")
import pyopencl

pygame.init()
screen = pygame.display.set_mode((1024, 768), pygame.HWSURFACE |
pygame.OPENGL | pygame.DOUBLEBUF)

if pyopencl.have_gl():
    context = pyopencl.create_some_context()
    tex = glGenTextures(1)
    glBindTexture(GL_TEXTURE_2D, tex)
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 256, 256, 0, GL_RGBA,
GL_UNSIGNED_BYTE, None)
    cltex = pyopencl.GLTexture(context, pyopencl.mem_flags.READ_ONLY,
GL_TEXTURE_2D, 0, tex, 2)

It fails with error:
Traceback (most recent call last):
  File "cl.py", line 14, in <module>
    cltex = pyopencl.GLTexture(context, pyopencl.mem_flags.READ_ONLY,
GL_TEXTURE_2D, 0, tex, 2)
pyopencl.LogicError: clCreateFromGLTexture2D failed: invalid context

I thought that the problem might be in pyopencl's context creation,
which doesn't take the GL context into account. I tried to fix it by
adding appropriate CL_GL_CONTEXT_KHR, CL_GLX_DISPLAY_KHR and
CL_CONTEXT_PLATFORM props to the context, but then I got another error
"pyopencl.LogicError: clCreateFromGLTexture2D failed: invalid value". I
can run kernels just fine with my setup, but this GL stuff won't work.
What am I doing wrong?