CODEWITHSUNDEEP
opengltextures
spinning
spinning

Reputation: 119

OpenGL color index in frag shader?

I have a large sprite library and I'd like to cut GPU memory requirements. Can I store textures on the gpu with only 1 byte per pixel and use that for an RGB color look up in a fragment shader? I see conflicting reports on the use of GL_R8.

Upvotes: 0

Views: 923

Answers (1)

Mario
Mario

Reputation: 36497

I'd say this really depends on whether your hardware supports that texture format or not. How about skipping the whole issue by using a A8R8G8B8 texture instead? It would just be compressed, i.e. using a bit mask (or r/g/b/a members in glsl) to read "sub pixel" values. Like the first pixel is stored in alpha channel, second pixel in red channel, third pixel in green channel, etc.

You could even use this to store up to 4 layers in a single image (cutting max texture width/height); picking just one shouldn't be an issue.

Upvotes: 3

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