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kard
05-22-2003, 08:14 AM
Hi,

I have some problems to make the GL_SGIS_generate_mipmap extension work with a one channel texture (GL_LUMINANCE) on a Radeon 9700 pro. The code below produces some black part in the low resolution textures (the 0 level one is the good one) :



glTexImage2D(GL_TEXTURE_2D,0,1,SizeU,SizeV,0,GL_LU MINANCE,GL_FLOAT,First);

If I replace the internal format (1/GL_LUMINANCE8) by GL_RGB8 the mipmaps are generated nicely.



glTexImage2D(GL_TEXTURE_2D,0,GL_RGB8,SizeU,SizeV,0 ,GL_LUMINANCE,GL_FLOAT,First);

Is there any limitation in the internal formats that are supported by the extension?

Thanks !

[This message has been edited by kard (edited 05-22-2003).]

[This message has been edited by kard (edited 05-22-2003).]

Coriolis
05-22-2003, 09:48 AM
Yes, there are limitations. Read more about it in the spec (http://oss.sgi.com/projects/ogl-sample/registry/SGIS/generate_mipmap.txt) .

Zeno
05-22-2003, 09:52 AM
ATI also has a driver bug related to this extension that I found. It's probably fixed in Cat 3.4, but I haven't checked:

http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/009011.html

kard
05-22-2003, 10:15 AM
Coriolis: I read the spec, and did not find any limitation concerning the internal format of the base texture. Could you be more precise?

Zeno: It seems to be the same pb... And I test it with the Catalyst 3.4... In your previous topic you mention something about textures with an internal/external format GL_ALPHA when uploaded as GL_FLOAT... Have you try to upload such a texture as non-float? I made some experiment and see that for some strange reasons non square dimensions annihilate the bug...

Thanks !

Cyril-

gimp
05-26-2003, 07:55 PM
I'm using GL_LUMINANCE to render my fonts. My standard texture creation path uses SGIS. I have not seen these problems.

I am using Cat3.4. I had a similar problem a few weeks back when getting the new PC, I thought it was 'my' code as I edited that section recently. I later switched to 'Omega' drivers(for other stuttering problems) and it seemed to fix the problem on my 9700 pro.