2.0
Because jPCT-AE log say:
WARNING: Texture's size is 256/128, but textures should be square for OpenGL ES2.0! This may result in a black texture!
When i use 256*128(or other texture which isn't square), all are fine, but because of the warning above, i prefer to make all textures to be square to avoid potential error.
Should I use (2^n * 2^m) or (2^n * 2^n)?
And to convert 512*128 -> 512*512, i won't use Bitmap.scale()(or other similar methods), i just use a file of 512*512 instead.