There seems to be very little online information on this topic. We have encountered problems using
texture arrays with PVRTC textures on IOS. We have a working code that produces correct results
when using ETC2 textures or uncompressed textures and which doesn't work correctly with PVRTC
textures. We are uploading the texture data using glCompressedTexImage3D(GL_TEXTURE_2D_ARRAY,...).
The weird thing is that we seem to get correct results with PVRTC if we multiply the layer coordinate
(third texture coordinate) by four when doing the sampling in the shader. Values not multiple of four result
in a kind of 'layer nearest neighbour filtering' where the four quarters of the quad show two different textures.
We have been hypothesizing whether PVRTC texture arrays may not work due to the square texture
constraint on IOS, since an array of square textures is not square. Does anyone know whether PVRTC
texture arrays are supported or not? Has anyone successfully used them?
Hello! It's been a while, but did you manage to solve this problem? Or figure out why is the multiplication by four necessary? I have exactly the same issue, but it looks like using the four factor helps only at small layer coordinates (for the first 2-3 layers).
Also here, it's been a while. Our solution to this problem was to switch to ASTC.