CODEWITHSUNDEEP
c++openglglsltexturesshader
Jan Rüegg
Jan Rüegg

Reputation: 10075

Possible to find internal format of texture in shader?

Is it possible to find the internal format of a texture within the shader (glsl)?

For example, if I have a texture with the format GL_RG, is it possible to recognize in the shader that the blue and alpha value are "constant" and can be ignored?

I know I can use a uniform to pass the texture type from c++ to the shaders. But is there an "intrinsic" way to find out from within the shader?

Upvotes: 4

Views: 249

Answers (1)

Reto Koradi
Reto Koradi

Reputation: 54652

No, I don't believe there is anything that would give you this information directly.

Looking at the latest GLSL spec (4.50 at this time), I would expect a hypothetical function to get this information to be listed in section "8.9.1. Texture Query Functions" starting on page 158. But the only functions listed there are:

  • textureSize: Get size of texture.
  • textureQueryLod: Get the level of detail used for the given texture coordinates.
  • textureQueryLevels: Get the number of mipmap levels in the texture.
  • textureSamples: Get the number of samples for a multisampled texture.

So unless there is something completely different I missed, what you're looking for does not exist.

Upvotes: 3

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