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Thread: Texture compression problem on a GeForce2

  1. #1
    Intern Contributor
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    Texture compression problem on a GeForce2

    I upload a 2D texture using :
    GL_COMPRESSED_RGB_ARB as internal format and
    GL_RGBA as format because my pixels (not compressed) are store on 4 bytes but I only use 3 components. So I don't care about alpha value. Nevertheless the rasterisation use the alpha component of the texture even if I not use the GL_COMPRESSED_RGBA_ARB ! Thus I must to set to 255 the alpha value (If I set 0 the texture appear black).

    Any idea ?

    David.
    NB : PixelStorage = 4

  2. #2
    Member Regular Contributor
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    Re: Texture compression problem on a GeForce2

    Is there any reason why you can't just convert the image to RGB?
    It's not difficult, and you'll save memory that way, which I assume is what you want to do if you're using compression.

  3. #3
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    Re: Texture compression problem on a GeForce2

    Yes of course, but I would like to keep the alignment...
    Originally posted by Don't Disturb:
    Is there any reason why you can't just convert the image to RGB?
    It's not difficult, and you'll save memory that way, which I assume is what you want to do if you're using compression.
    Moreover, I was not sure before but now I'm sure that NVidia driver (about this extension) has a bad behaviour !

  4. #4
    Senior Member OpenGL Pro
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    Re: Texture compression problem on a GeForce2

    I think this is a real bug. In the meantime, use alpha of 128 or higher or use RGB, not RGBA.

    - Matt

  5. #5
    Senior Member OpenGL Pro cass's Avatar
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    Re: Texture compression problem on a GeForce2

    Sancho,

    Can you provide a simple test app that illustrates the bug?

    This will expedite getting it fixed. Otherwise it'll have to wait until I get the opportunity to write one.

    If you have something, please email it to cass@nvidia.com.

    Thanks -
    Cass
    Cass Everitt -- cass@xyzw.us

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