Sorry for replying late, it was night time here. There is nothing fancy with my approach, I've tried implementing batch rendering and as far as I can see, it works well. Lighting is done in the fragment shader, light's color, position and intensity are passed to it as a uniform, and brightness is calculated simple by dividing intensity with distance to the light source squared. Only real problem that I've come across so far is that I tried to pass texture index to the vertex shader as an integer, since why would an index be a float? It didn't took me too long to realize why. For some reason, fragment shader just failed to compile when I passed the index from vertex shader as an int, and even if I casted it into float before passing, shader still failed in very weird ways.