precision highp float;

// Compiler should remove unneeded stuff
uniform vec3 view_position;

uniform vec3 light_globalAmbient;

varying vec3 vPositionW;
varying vec3 vNormalW;
varying vec3 vTangentW;
varying vec3 vBinormalW;
varying vec2 vUv0;
varying vec2 vUv1;
varying vec4 vVertexColor;
varying vec3 vNormalV;

struct psInternalData {
    vec3 albedo;
    vec3 specularity;
    float glossiness;
    vec3 emission;
    vec3 normalW;
    mat3 TBN;
    vec3 viewDirW;
    vec3 reflDirW;
    vec3 diffuseLight;
    vec3 specularLight;
    float alpha;
    vec3 lightDirNormW;
    vec3 lightDirW;
    float atten;
    vec3 shadowCoord;
    vec2 uvOffset;
};

void getViewDir(inout psInternalData data) {
    data.viewDirW = normalize(view_position - vPositionW);
}

void getReflDir(inout psInternalData data) {
    data.reflDirW = normalize(-reflect(data.viewDirW, data.normalW));
}

void addAmbientConstant(inout psInternalData data) {
    data.diffuseLight += light_globalAmbient;
}

void getLightDirPoint(inout psInternalData data, vec3 lightPosW) {
    data.lightDirW = vPositionW - lightPosW;
    data.lightDirNormW = normalize(data.lightDirW);
}

float getFalloffLinear(inout psInternalData data, float lightRadius) {
    float d = length(data.lightDirW);
    return max(((lightRadius - d) / lightRadius), 0.0);
}

float getFalloffInvSquared(inout psInternalData data) {
    float sqrDist = dot(data.lightDirW, data.lightDirW);
    return 1.0 / sqrDist;
}

float getSpotEffect(inout psInternalData data, vec3 lightSpotDirW, float lightInnerConeAngle, float lightOuterConeAngle) {
    float cosAngle = dot(data.lightDirNormW, lightSpotDirW);
    return smoothstep(lightOuterConeAngle, lightInnerConeAngle, cosAngle);
}

varying vec2 vUvDiffuse;
varying vec2 vUvNormal;
varying vec2 vUvHeight;
uniform vec3 light0_color;
uniform vec3 light0_direction;
uniform mat4 light0_shadowMatrix;
uniform vec3 light0_shadowParams;
uniform sampler2D light0_shadowMap;
uniform vec3 light1_color;
uniform vec3 light1_position;
uniform float light1_radius;
uniform vec3 light2_color;
uniform vec3 light2_position;
uniform float light2_radius;
uniform vec3 light3_color;
uniform vec3 light3_position;
uniform float light3_radius;
uniform vec3 light4_color;
uniform vec3 light4_position;
uniform float light4_radius;
uniform vec3 light4_spotDirection;
uniform float light4_innerConeAngle;
uniform float light4_outerConeAngle;
uniform mat4 light4_shadowMatrix;
uniform vec3 light4_shadowParams;
uniform sampler2D light4_shadowMap;

uniform sampler2D texture_normalMap;
uniform float material_bumpMapFactor;
void getNormal(inout psInternalData data) {
    vec3 normalMap = texture2D(texture_normalMap, vUvNormal + data.uvOffset).xyz * 2.0 - 1.0;
    normalMap = normalize(mix(vec3(0.0, 0.0, 1.0), normalMap, material_bumpMapFactor));

    data.normalW = data.TBN * normalMap;
}

void getTBN(inout psInternalData data) {
    data.TBN = mat3(normalize(vTangentW), normalize(vBinormalW), normalize(vNormalW));
}

vec4 texture2DAlbedo(sampler2D tex, vec2 uv) {
    vec4 rgba = texture2D(tex, uv);
    rgba.rgb = pow(rgba.rgb, vec3(2.2)); // when no sRGB extension available
    return rgba;
}

vec3 gammaCorrectOutput(vec3 color) {
    return pow(color, vec3(0.45));
}

uniform sampler2D texture_diffuseMap;
void getAlbedo(inout psInternalData data) {
    vec4 tex = texture2DAlbedo(texture_diffuseMap, vUvDiffuse + data.uvOffset);
    data.albedo = tex.rgb;
}

uniform float material_shininess;
void getGlossiness(inout psInternalData data) {
    // Hack: On Mac OS X, calling pow with zero for the exponent generates hideous artifacts so bias up a little
    data.glossiness = material_shininess + 0.0001;
}

uniform float material_opacity;
void getOpacity(inout psInternalData data) {
    data.alpha = material_opacity;
}

uniform vec3 material_emissive;
vec3 getEmission(inout psInternalData data) {
    return material_emissive;
}

uniform sampler2D texture_heightMap;
void getParallax(inout psInternalData data) {
    const float parallaxScale = 0.025;
    const float parallaxBias = 0.01;

    float height = texture2D(texture_heightMap, vUvHeight).r * parallaxScale - parallaxBias;
    vec3 viewDirT = data.viewDirW * data.TBN;

    data.uvOffset = min(height * viewDirT.xy, vec2(parallaxBias));
}

float unpackFloat(vec4 rgbaDepth) {
    const vec4 bitShift = vec4(1.0 / (256.0 * 256.0 * 256.0), 1.0 / (256.0 * 256.0), 1.0 / 256.0, 1.0);
    return dot(rgbaDepth, bitShift);
}

void getShadowCoord(inout psInternalData data, mat4 shadowMatrix, vec3 shadowParams) {
    vec4 projPos = shadowMatrix * vec4(vPositionW, 1.0);
    projPos.xyz /= projPos.w;
    projPos.z += shadowParams.z;
    data.shadowCoord = projPos.xyz;
}

bool shadowContained(psInternalData data) {
    bvec4 containedVec = bvec4(data.shadowCoord.x >= 0.0, data.shadowCoord.x <= 1.0, data.shadowCoord.y >= 0.0, data.shadowCoord.y <= 1.0);
    return all(bvec2(all(containedVec), data.shadowCoord.z <= 1.0));
}

float getShadow(inout psInternalData data, sampler2D shadowMap, vec3 shadowParams) {
    if (shadowContained(data)) {
        float depth = unpackFloat(texture2D(shadowMap, data.shadowCoord.xy));
        return (depth < data.shadowCoord.z) ? 0.0 : 1.0;
    }
    return 1.0;
}

float getShadowPCF3x3(inout psInternalData data, sampler2D shadowMap, vec3 shadowParams) {
    if (shadowContained(data)) {
        float shadowAccum = 0.0;
        vec3 shadowCoord = data.shadowCoord;

        float xoffset = 1.0 / shadowParams.x; // 1/shadow map width
        float yoffset = 1.0 / shadowParams.y; // 1/shadow map height
        float dx0 = -xoffset;
        float dy0 = -yoffset;
        float dx1 = xoffset;
        float dy1 = yoffset;

        mat3 shadowKernel;
        mat3 depthKernel;

        depthKernel[0][0] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(dx0, dy0)));
        depthKernel[0][1] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(dx0, 0.0)));
        depthKernel[0][2] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(dx0, dy1)));
        depthKernel[1][0] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(0.0, dy0)));
        depthKernel[1][1] = unpackFloat(texture2D(shadowMap, shadowCoord.xy));
        depthKernel[1][2] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(0.0, dy1)));
        depthKernel[2][0] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(dx1, dy0)));
        depthKernel[2][1] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(dx1, 0.0)));
        depthKernel[2][2] = unpackFloat(texture2D(shadowMap, shadowCoord.xy + vec2(dx1, dy1)));

        vec3 shadowZ = vec3(shadowCoord.z);
        shadowKernel[0] = vec3(lessThan(depthKernel[0], shadowZ));
        shadowKernel[0] *= vec3(0.25);
        shadowKernel[1] = vec3(lessThan(depthKernel[1], shadowZ));
        shadowKernel[1] *= vec3(0.25);
        shadowKernel[2] = vec3(lessThan(depthKernel[2], shadowZ));
        shadowKernel[2] *= vec3(0.25);

        vec2 fractionalCoord = 1.0 - fract( shadowCoord.xy * shadowParams.xy );

        shadowKernel[0] = mix(shadowKernel[1], shadowKernel[0], fractionalCoord.x);
        shadowKernel[1] = mix(shadowKernel[2], shadowKernel[1], fractionalCoord.x);

        vec4 shadowValues;
        shadowValues.x = mix(shadowKernel[0][1], shadowKernel[0][0], fractionalCoord.y);
        shadowValues.y = mix(shadowKernel[0][2], shadowKernel[0][1], fractionalCoord.y);
        shadowValues.z = mix(shadowKernel[1][1], shadowKernel[1][0], fractionalCoord.y);
        shadowValues.w = mix(shadowKernel[1][2], shadowKernel[1][1], fractionalCoord.y);

        shadowAccum = 1.0 - dot( shadowValues, vec4( 1.0 ) );

        return shadowAccum;
    }
    return 1.0;
}

float getLightDiffuse(inout psInternalData data) {
    return max(dot(data.normalW, -data.lightDirNormW), 0.0);
}

vec3 combineColor(inout psInternalData data) {
    return data.albedo * data.diffuseLight;
}


void main(void) {
   psInternalData data;
   data.diffuseLight = vec3(0);
   data.specularLight = vec3(0);


   getViewDir(data);
   getTBN(data);
   getParallax(data);
   getNormal(data);
   getAlbedo(data);
   getOpacity(data);
   addAmbientConstant(data);
   data.lightDirNormW = light0_direction;
   data.atten = 1.0;
   data.atten *= getLightDiffuse(data);
   getShadowCoord(data, light0_shadowMatrix, light0_shadowParams);
   data.atten *= getShadowPCF3x3(data, light0_shadowMap, light0_shadowParams);
   data.diffuseLight += data.atten * light0_color;

   getLightDirPoint(data, light1_position);
   data.atten = getFalloffLinear(data, light1_radius);
   data.atten *= getLightDiffuse(data);
   data.diffuseLight += data.atten * light1_color;

   getLightDirPoint(data, light2_position);
   data.atten = getFalloffLinear(data, light2_radius);
   data.atten *= getLightDiffuse(data);
   data.diffuseLight += data.atten * light2_color;

   getLightDirPoint(data, light3_position);
   data.atten = getFalloffLinear(data, light3_radius);
   data.atten *= getLightDiffuse(data);
   data.diffuseLight += data.atten * light3_color;

   getLightDirPoint(data, light4_position);
   data.atten = getFalloffLinear(data, light4_radius);
   data.atten *= getSpotEffect(data, light4_spotDirection, light4_innerConeAngle, light4_outerConeAngle);
   data.atten *= getLightDiffuse(data);
   getShadowCoord(data, light4_shadowMatrix, light4_shadowParams);
   data.atten *= getShadowPCF3x3(data, light4_shadowMap, light4_shadowParams);
   data.diffuseLight += data.atten * light4_color;


   gl_FragColor.rgb = combineColor(data);
   gl_FragColor.rgb += getEmission(data);
   gl_FragColor.rgb = gammaCorrectOutput(gl_FragColor.rgb);
   gl_FragColor.a = data.alpha;
}