Can we copy a textures from source GL_RGBA8 (GL_UNSIGNED_BYTE) to a destination GL_RGB8_SNORM (GL_BYTE)? This combination some how works in opengl 3.3, but want to check for opengl 'es' 3.0. Or is it mandatory to have same source format as GL_RGB8_SNORM for destination GL_RGB8_SNORM to work in opengl es 3.0? I think first should work for es 3.0 as well. Please correct me if I am wrong.