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View Full Version : ATI, glGetTexImage + GL_PIXEL_PACK_BUFFER problem



Nicolas Lelong
05-07-2010, 10:25 AM
Hi everyone,

I'm currently trying to read the contents of textures to dump their raw contents on disk.

I'm trying to use PBOs (GL_PIXEL_PACK_BUFFER) as glGetTexImage is supposed to raise a GL_INVALID_OPERATION error if there's not enough memory in the PBO.

Everything is fine on NVidia, but on ATI I have unexpected GL_INVALID_OPERATION errors happening on certain pixel formats :
GL_R3_G3_B2, supposed to be 1 byte per pixel GL_RGB16, supposed to be 6 bytes per pixel GL_RGB32F, supposed to be 12 bytes per pixel GL_RGB8, supposed to be 3 bytes per pixel ...
I've checked without using PBO, and the reserved texture space seems to be correcly calculated by my code (I added bound checking to my buffers). I also use a GL_PACK_ALIGNMENT value of 1.

Does anyone have experience to share about using 'correctly' sized PBO to read texture contents ?

Cheers,
Nicolas.

Edit: forgot to mention the use of Catalyst 10.4 on Radeon HD5770

DmitryM
05-07-2010, 10:58 AM
I'm using RG16 with PBO successfully on ATI now. RG8 doesn't work correctly though, without any error set up.