Before this, the BoneTransforms uniform block consumed
(4 * 4 * sizeof(float) * MAX_BONES) = 19712 bytes, which exceeds 16384,
the minimum possible value of GL_MAX_UNIFORM_BLOCK_SIZE in OpenGL ES
3.2.
Since the bone matrices are affine, we can drop the 4th rows and pack
them into a mat4x3 array. Now the BoneTransforms block is 14784 bytes
and it should work with all OpenGL ES 3.2 implementations.
kichikuou
9b03741288