I tried to equate gl_FragData[0] to MatR and it does not work because they are of data different types (vec4 and mat4). Also, it does not make sense to use 4 framebuffers to store the matrix data.
I could not use OpenCL cos my platform supports OpenGL and OpenGL SL
Again, why do you do it on GPU in the first place? It does not make sense to perform matrix multiplication on the GPU just to read it backā¦ and if want to do it, you MUST use 4 color buffers, just to pack the data!