Re: [PyOpenGL-Users] Problem attaching Texture to FBO on intel GMA 45000MHD (error when calling glFramebufferTexture2DEXT)

[Thomas H. <tho...@gm...>]

I figured out a workaround.  If I disable OpenGL.ERROR_CHECK,
everything works just fine.  If I get the error code after calling
glFramebufferTexture2DEXT, it does not return a bad code, but instead
the expected GL_FRAMEBUFFER_COMPLETE_EXT code.  So I'm guessing there
is a bug in the error checking somewhere?

It's funky behavior though, and only happens on this laptop (but I've
tried with all the 3.0 > pyOpenGL version).  Another odd thing is that
bool(glGenFrameBuffersEXT) returns false, although the function
clearly exists.

So still not sure exactly why this is happening, but at least it works
with minor work around (would be nice for debugging if I could get the
auto ERROR_CHECK to work at teh same time though)

--
Thomas



On Thu, Feb 4, 2010 at 12:06 PM, Thomas Hansen <tho...@gm...> wrote:
> Hi everyone,
>
> I using PyOpenGL 3.0.1b2 on Windows 7 on a Dell XT 2 tablet PC
> (http://www.dell.com/tablet). The tablet has a intel GMA  4500MHD
> graphics chip with the newest drivers from intel installed. I'm having
> problems creating a Framebuffer object using pyOpenGL.  The following
> code runs fine on every machine I have access to except for this one.
> I know the graphics chip has FBO support, and have successfully
> compiled and run various C programs using FBO's.
>
> The problem occurs when I call glFramebufferTexture2DEXT, to attach my
> texture to the FBO.  The program crashes and prints a traceback with
> GL error code 1286, which I believe is
> INVALID_FRAMEBUFFER_OPERATION_EXT.
>
> If anyone knows what I am doing wrong, has a workaround, or even just
> a suggestion of identifying the problem better, I would be very
> thankful.
>
> I'm posting a code snippet and the output it produces.  I know teh
> code isnt complete and nothing is actually done with the fbo etc.  but
> its enough to crash the program, and demonstrates the first problem I
> encounter on this machine.
>
> The code:
> =======================================================================
> import pygame
> from pygame.locals import *
> from OpenGL.GL import *
> from OpenGL.GL.EXT.framebuffer_object import *
>
> def draw ():
>   glClearColor(0.0,0.0,0.0,0.0)
>   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
>   #draw stuff here
>   pygame.display.flip()
>
> pygame.init()
> pygame.display.set_mode((512,512),OPENGL | DOUBLEBUF)
>
> #setup a texture
> tex = glGenTextures(1);
> glBindTexture(GL_TEXTURE_2D, tex);
> glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 512, 512, 0, GL_RGBA,
> GL_UNSIGNED_BYTE, None);
> glBindTexture(GL_TEXTURE_2D, 0);
>
> #setup teh fbo
> fbo = glGenFramebuffersEXT(1)
> glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo)
> glBindTexture(GL_TEXTURE_2D, tex)
>
> #this call produces an error!
> glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
> GL_COLOR_ATTACHMENT0_EXT,GL_TEXTURE_2D, tex, 0)
>
> while 1:
>  event=pygame.event.poll ()
>  if event.type is QUIT:
>   sys.exit(0)
>  draw()
>
>
> Here is the output:
> ===================================================================
> Traceback (most recent call last):
>  File "test.py", line 29, in <module>
>    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
> GL_COLOR_ATTACHMENT0_EXT,GL_TEXTURE_2D, tex, 0)
>  File "C:\Python26\lib\site-packages\pyopengl-3.0.1b2-py2.6-win32.egg\OpenGL\platform\baseplatform.py",
> line 335, in __call__
>    return self( *args, **named )
>  File "C:\Python26\lib\site-packages\pyopengl-3.0.1b2-py2.6-win32.egg\OpenGL\error.py",
> line 208, in glCheckError
>    baseOperation = baseOperation,
> OpenGL.error.GLError: GLError(
>        err = 1286,
>        baseOperation = glFramebufferTexture2DEXT,
>        cArguments = (
>                GL_FRAMEBUFFER_EXT,
>                GL_COLOR_ATTACHMENT0_EXT,
>                GL_TEXTURE_2D,
>                1L,
>                0,
>        )
> )
>
>
> Thanks alot!!
>
> --
> Thomas Hansen
>