#version 410

layout(location = 0) in vec3 colorin;
layout(location = 1) in vec3 normal;
layout(location = 2) in vec3 pos;
layout(location = 3) in vec4 lightviewpos[3];
layout(location = 8) in vec2 UV;

uniform int numLights;
uniform sampler2D ShadowMaps[3];
uniform vec3 lightpos[3];
uniform vec3 lightColor[3];

layout(location = 0) out vec4 colorOut;
layout(location = 1) out float depth;


const float ambientFactor = 0.25;
const float diffuseFactor = 0.5;
const float specFactor = 1.0;
const float shininess = 16.0;
const float screenGamma = 2.2;
const float pitl = 2*3.14159265359 / 16.0;
const float circlelength = 700.0;

bool isVisible(int i, vec2 offs, float lambertian)
{
    float bias = 0.005*tan(acos(lambertian));
    bias = clamp(bias,0.0,0.01);//*tan(acos(dot(normal,-normalize(lightpos[i] - pos.xyz))));
    return !(texture(ShadowMaps[i],lightviewpos[i].xy + offs).x < (lightviewpos[i].z - bias));
}

void main()
{
    vec3 colorLinear = ambientFactor * colorin;

    for(int i = 0; i < numLights; i++){
        vec3 lightDir = -normalize(lightpos[i] - pos.xyz);
        float lambertian = max(dot(normalize(normal),lightDir),0.0);
        float cosTheta = clamp(dot(normalize(normal),-lightDir), 0.0, 1.0);
        float specular = 0;
        vec3 viewDir = normalize(-pos.xyz);
        vec3 halfDir = normalize(lightDir + viewDir);
        float specAngle = max(dot(halfDir, normalize(normal)), 0.0);
        specular = int(lambertian > 0)*pow(specAngle, shininess);
        //int visible = int(!(texture(ShadowMaps,lightpos[i].xy/2 + vec2(0.5,0.5)).z < (lightpos[i].z)));
        float visible = 0;
        for(int j = 0; j < 4; j++){
            vec2 offs = vec2(cos(j*4*pitl),sin(j*4*pitl)) / circlelength;
            visible += float(isVisible(i, offs,cosTheta)) * 1.0/16.0;
        }
        if(visible == 0.25)
            visible = 1.0;
        else
            visible = 0;
            for(int j = 0; j < 16; j++){
                vec2 offs = vec2(cos(j*pitl),sin(j*pitl)) / circlelength;
                visible += float(isVisible(i, offs,cosTheta)) * 1.0/16.0;
            }
        colorLinear +=   (visible * 0.5 + 0.5) *(lambertian * diffuseFactor * colorin * lightColor[i] + specular * specFactor*colorin);

        colorLinear /= dot(lightpos[i] - pos.xyz, lightpos[i] - pos.xyz)/200;
        //colorLinear = vec3(visible * specular);
    }

    vec3 colorGammaCorrected = colorLinear;//pow(colorLinear, vec3(1.0/screenGamma));


    //colorOut = vec4(colorin, 1.0)*max(dot(normal,normalize(vec3(0.0,0.0,10.0)-pos)),0.0);
    colorOut = vec4(colorGammaCorrected,1.0) * float(gl_FragCoord.y <= 768 && gl_FragCoord.x <= 1024 && gl_FragCoord.x >= 0 && gl_FragCoord.y >= 0);

    depth = gl_FragCoord.z;
}