I have a very low res mobile game I'm working on that takes multiple rendering passes followed by a pass the composes them. Currently, I have a tex for each pass- each of which gets given to the shader for final composition.
I want to keep # of textures used low, and I'm only able to sample from so many textures per-shader anyways (esp. for mobile). So I'm thinking each render pass would instead render to a portion of a single, bigger texture. Then the composition pass would sample the same texture from multiple places. Are there any red flags that pop out regarding this strategy?
My biggest worry is it would totally thrash the texel cache (since every frame, every pixel samples the exact same texels for all the textures (each texture is a 1 to 1 mapping of the screen) = incredibly predictable/efficient caching. However, I really only have a very basic understanding of how that works so I could be totally wrong.
Also, note that my game is incredibly low resolution (128x256), so a single "giant" texture that could hold maybe 6 screens would still be pretty small at the end of the day.
Any insight is helpful! Thanks!