[PyOpenGL-Users] bug in glDrawBuffers?

[Gijs <in...@bo...>]

Hello List,

I am trying to use glDrawBuffers to render to multiple textures using 
shaders. However, I'm running into a problem (otherwise I wouldn't be 
posting here ofcourse :) ). When I call glDrawBuffers with *any* 
buffer-type, it fails with the following error:

  File 
"/Library/Python/2.5/site-packages/OpenGL/platform/baseplatform.py", 
line 275, in __call__
    return self( *args, **named )
  File "/Library/Python/2.5/site-packages/OpenGL/error.py", line 194, in 
glCheckError
    baseOperation = baseOperation,
OpenGL.error.GLError: GLError(
    err = 1280,
    description = 'invalid enumerant',
    baseOperation = glDrawBuffers,
    cArguments = (
        1,
        [
        GL_COLOR_ATTACHMENT0_EXT
    ],
    )
)

This is ofcourse just an example but I want to use it to enable 8 
buffers (the maximum that is supported by my card). When I call 
glDrawBuffer with GL_COLOR_ATTACHMENT0_EXT it does work so I know it 
*should* work. I am using python 2.5.1 and Mac OS X 10.5. Below is part 
of my test-render code for 3 buffers:

glUseProgram(p_multiple_output)
 
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, b_multiple_output)

glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, int(input_images[0]))
glActiveTexture(GL_TEXTURE1)
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, int(input_images[1]))
glActiveTexture(GL_TEXTURE2)
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, int(input_images[2]))
 
glActiveTexture(GL_TEXTURE0)

drawingBuffers = list([GL_COLOR_ATTACHMENT0_EXT, 
GL_COLOR_ATTACHMENT1_EXT, GL_COLOR_ATTACHMENT2_EXT])
glDrawBuffers(3, drawingBuffers)
 
glCallList(quadid)


Hope someone knows what's going on under the hood.

Regards