Hi,

I'm trying to do some rendering to cube maps, and I ran into this bug.

the code below crashes on the glCheckFramebuffer() call, on this machine :
xUbuntu 12.04 64 bit, Catalyst 12.8 64 bit, AMD A8-4500M
I believe this is a driver bug, because the frame stack ended there.
So is this one? Or am I doing something wrong?


GLuint cubemap_tex = 0;
int w = 256;
int h = 256;

glGenTextures( 1, &cubemap_tex );
glBindTexture( GL_TEXTURE_2D, cubemap_tex );

glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR );

glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_X, 0, GL_RGBA16F, w, h, 0, GL_RGBA, GL_FLOAT, 0 );
glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_Y, 0, GL_RGBA16F, w, h, 0, GL_RGBA, GL_FLOAT, 0 );
glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_Z, 0, GL_RGBA16F, w, h, 0, GL_RGBA, GL_FLOAT, 0 );
glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_X, 0, GL_RGBA16F, w, h, 0, GL_RGBA, GL_FLOAT, 0 );
glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, 0, GL_RGBA16F, w, h, 0, GL_RGBA, GL_FLOAT, 0 );
glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, 0, GL_RGBA16F, w, h, 0, GL_RGBA, GL_FLOAT, 0 );

GLuint cubemap_fbo = 0;

glGenFramebuffers( 1, &cubemap_fbo );
glBindFramebuffer( GL_FRAMEBUFFER, cubemap_fbo );

GLenum mode = GL_COLOR_ATTACHMENT0;
glDrawBuffers( 1, &mode );

glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X, cubemap_tex, 0 );

GLenum error_code = glCheckFramebufferStatus( GL_FRAMEBUFFER ); //crashes here
glBindFramebuffer( GL_FRAMEBUFFER, 0 );


Best regards,
Yours3lf

Try calling [font=courier new,courier,monospace]glGetError()[/font] after every OpenGL call to see if any of them are creating a problematic/erroneous state. I also came across this, which may be of some help.

Try calling [font=courier new,courier,monospace]glGetError()[/font] after every OpenGL call to see if any of them are creating a problematic/erroneous state. I also came across this, which may be of some help.

thanks for the reply, but getting the errors didn't help (no errors), still crashes... however what you linked in gave me an idea, and I replaced the texture binding call with:
glBindTexture( GL_TEXTURE_CUBE_MAP, cubemap_tex );

and this solved the problem. So I believe this is a driver bug. It shouldn't crash under any circumstances, right?

It shouldn't crash under any circumstances, right?

Well... not necessarily. For example, if you give it a garbage pointer or size and cause it to commit an access violation, it's free to crash.

I'm not much of a video programmer, but here's my guess as to why it crashed: glTexImage2D requires you to pass a pointer to the texture data, and in your OP you're passing 0. If you read the docs for that function, it says "If [font=courier new,courier,monospace]target[/font] is [font=courier new,courier,monospace]GL_PROXY_TEXTURE_2D[/font], [font=courier new,courier,monospace]GL_PROXY_TEXTURE_1D_ARRAY[/font], [font=courier new,courier,monospace]GL_PROXY_TEXTURE_CUBE_MAP[/font], or [font=courier new,courier,monospace]GL_PROXY_TEXTURE_RECTANGLE[/font], no data is read from data." In the next paragraph, it says "If target is [font=courier new,courier,monospace]GL_TEXTURE_2D[/font], [font=courier new,courier,monospace]GL_TEXTURE_RECTANGLE[/font] or one of the [font=courier new,courier,monospace]GL_TEXTURE_CUBE_MAP[/font] targets, data is read from data..." (emphasis mine) This may explain why it crashes. I could be wrong, but that's my hunch.

[quote name='Yours3!f' timestamp='1353782686' post='5003794']
It shouldn't crash under any circumstances, right?

Well... not necessarily. For example, if you give it a garbage pointer or size and cause it to commit an access violation, it's free to crash.

I'm not much of a video programmer, but here's my guess as to why it crashed: glTexImage2D requires you to pass a pointer to the texture data, and in your OP you're passing 0. If you read the docs for that function, it says "If [font=courier new,courier,monospace]target[/font] is [font=courier new,courier,monospace]GL_PROXY_TEXTURE_2D[/font], [font=courier new,courier,monospace]GL_PROXY_TEXTURE_1D_ARRAY[/font], [font=courier new,courier,monospace]GL_PROXY_TEXTURE_CUBE_MAP[/font], or [font=courier new,courier,monospace]GL_PROXY_TEXTURE_RECTANGLE[/font], no data is read from data." In the next paragraph, it says "If target is [font=courier new,courier,monospace]GL_TEXTURE_2D[/font], [font=courier new,courier,monospace]GL_TEXTURE_RECTANGLE[/font] or one of the [font=courier new,courier,monospace]GL_TEXTURE_CUBE_MAP[/font] targets, data is read from data..." (emphasis mine) This may explain why it crashes. I could be wrong, but that's my hunch.
[/quote]

well it is read if not 0 is passed.
"data may be a null pointer.
In this case, texture memory is
allocated to accommodate a texture of width width and height height.
You can then download subtextures to initialize this
texture memory.
The image is undefined if the user tries to apply
an uninitialized portion of the texture image to a primitive."

and that function didn't crash, but the fbo checker. And that function doesn't receive any pointer.

Shows how much I know

if after calling glTexParameteri( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE ); you did not get error with glGetError then it is a driver bug that it is not reporting error. Because you were binding 2D texture, but operating with cubemap texture.

Thanks I'll report this.