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Thread: Blending and clamping

  1. #1
    Junior Member Regular Contributor Kopelrativ's Avatar
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    Apr 2011
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    Blending and clamping

    According to glBlendFunc all scale factors have the range [0,1] and according to glBlendEquation all values are clamped to [0,1].

    I can understand this if the image format is GL_RGBA8, but not if it is a floating point format. Have I understood this correctly?

    If so, what is the reason?

    It makes it harder if you want to do HDR imaging.

  2. #2
    Senior Member OpenGL Guru
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    Don't blame me; that's how the man pages have always described it.

    Those descriptions are inaccurate. The clamping behavior only exists when writing to non-float-point or non-integral targets. And division by whatever also only matters when dealing with fixed-function.

    In short, they do what you think they do, not what they say. Feel free to update the pages; that's why they're on the Wiki.

  3. #3
    Junior Member Regular Contributor Kopelrativ's Avatar
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    Apr 2011
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    Thanks for the confirmation, I updated the Wiki.

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