#version 330 core
#extension GL_ARB_shading_language_420pack : enable

uniform mat4 projection_matrix;
uniform mat4 view_matrix;
uniform mat4 model_matrix;

const uint lights = 2u;

const vec3 lightPos[lights] = {vec3(2.0, -2.0, 10.0),
      	   		       vec3(2.0, 2.0, 10.0)};
const vec3 lightColor[lights] = {vec3(1.0, 0.9, 0.8),
          	   		 vec3(0.0, 1.0, 0.0)};
const float lightIntensity[lights] = {75.0, 25.0};


layout(location = 0) in vec3 vertex;
layout(location = 1) in vec2 vertexTC;
layout(location = 2) in vec3 vertexNorm;

out vec2 fragTC;
out vec3 lightColors[lights];
out vec3 lightVecs[lights];

void main(void) {
     vec4 vertex_Pos = model_matrix * vec4(vertex, 1.0);
     gl_Position = projection_matrix * view_matrix * vertex_Pos;
     
     fragTC = vertexTC;
     
     vec3 vertexNorm_trans = (model_matrix*vec4(vertexNorm, 0.0)).xyz;
     
     for (uint i = 0u;i < lights;++i) {
     	 vec3 lightVec = lightPos[i]-vertex_Pos.xyz;
	 lightVecs[i] = -lightVec;
     	 vec3 lightNorm = normalize(lightVec);
	 float lightDist = length(lightVec);
     	 lightColors[i] = lightColor[i]*clamp(dot(vertexNorm_trans, lightNorm), 0.0, 1.0)*
	 	          clamp(lightIntensity[i]/(lightDist*lightDist), 0.0, 1.0);
     }
}