I have been trying to load compressed textures on OS X and in OpenGL ES 2 on RPi 3, with
I compressed a png with crunch-osx like this:
crunch -file 01.png -fileformat ktx -etc1
The texture seems to be loaded, but nothing is shown, while uncompressed ktx, without the -etc1 option seems to be working, but since it is not compressed it has no use for me at the moment.
Could you suggest a way to load compressed textures in OpenGL ES 2?