#version 330 core

// material
uniform vec3 materialKd;
uniform vec3 materialKs;
uniform float materialNs;

uniform int nbDirLights;
uniform vec3 dirLights[8];
uniform int nbPointLights;
uniform vec3 pointLights[8];

// texture
uniform sampler2D baseTexture;

// fragment
in vec3 varNormal;
in vec2 varTexCoord;

in vec3 lightDirInView[4];
in vec3 halfVecInView[4];

// resultat
layout(location = 0)out vec4 outColor;

// --------------------

vec3 computeLight(in vec3 kd, in vec3 ks, in float ns, in vec3 color, in vec3 normal, in vec3 lightDir, in vec3 halfVec){
	float diffuse = 0;
	float specular = 0;

	diffuse = dot(normal, lightDir);
	diffuse = diffuse < 0 ? 0 : diffuse;
	specular = dot(halfVec, normal);
	specular = specular < 0 ? 0 : specular;

	return color*diffuse*(kd+ks*pow(specular, ns));
}

void main(void) {
	int i;
	vec3 kd = vec3(0.5);
	vec3 light = 0.1*kd;
	vec3 myNormal = normalize(varNormal + 0.3 - 0.6*vec3(texture2D(baseTexture, varTexCoord)));
	for(i=0; i<nbDirLights && i<4; ++i)
		light += computeLight(kd, materialKs, materialNs, dirLights[i*2+1], myNormal, lightDirInView[i], halfVecInView[i]);
	for(i=0; i<nbPointLights && i+nbDirLights<4; ++i)
		light += computeLight(kd, materialKs, materialNs, pointLights[i*2+1], myNormal, lightDirInView[nbDirLights+i], halfVecInView[nbDirLights+i]);

	outColor = vec4(light, 1);
}