recently, i started thinking about the lights in a project. So i first look for some topics talking about that, i saw the "This is not a game" way to do that, but i didn't found this method apropriate. Then I found PixelEffects. I learned GLSL language and tried to make my own light effect, and I did it

But in my game, i want more than one light source, so i started to modify the shader in a way that it can handle 32 light sources, multidirectional or unidirectional. The problems comes here, despite my best efforts, only one source is displayed at a time...
I hope someone could read my work and, maybe, found the problem, it would help me a lot !
Here's the shader.
Thank you beforehand, and sorry for the english, not my first language
