struct Material {
	vec3 albedo;
	vec3 emission;
	vec3 f0;
	vec3 f82; // hardcoded metals only
	float roughness;
	float sss_amount;
	float sheen_amount; // SSS "sheen" for tall grass
	float porosity;
	float ssr_multiplier;
	float normal_multiplier; // normal map multiplier for generated normals
	bool is_metal;
	bool is_hardcoded_metal;
};




#ifdef GENERATED_NORMALS
    #include "/lib/surface/generatedNormals.glsl"
#endif



void GetMaterials(out float smoothness, out float metalness, out float f0, inout float emission,
                  inout float subsurface, out float porosity, out float ao, out vec3 normalMap,
                  vec2 newCoord, vec2 dcdx, vec2 dcdy)
{
    float emissionMat = 0.0;



    #if MATERIAL_FORMAT == 0
        #ifdef PARALLAX
        vec4 specularMap = texture2DGradARB(specular, newCoord, dcdx, dcdy);
        #else
        vec4 specularMap = texture2D(specular, texCoord);
        #endif

        smoothness = specularMap.r;

        f0 = 0.04;
        metalness = specularMap.g;

        emissionMat = specularMap.b * specularMap.b;

        porosity = 0.5 - 0.5 * smoothness;
        subsurface = specularMap.a > 0.0 ? 1.0 - specularMap.a : 0.0;

        #ifdef PARALLAX
        normalMap = texture2DGradARB(normals, newCoord, dcdx, dcdy).xyz * 2.0 - 1.0;
        #else
        normalMap = texture2D(normals, texCoord).xyz * 2.0 - 1.0;
        #endif
        ao = 1.0;

        if (normalMap.x + normalMap.y < -1.999) normalMap = vec3(0.0, 0.0, 1.0);
    #endif

    #if MATERIAL_FORMAT == 1
        vec4 specularMap = texture2DLod(specular, newCoord, 0);
        smoothness = specularMap.r;

        f0 = specularMap.g;
        metalness = f0 >= 0.9 ? 1.0 : 0.0;

        emissionMat = specularMap.a < 1.0 ? clamp(specularMap.a * 1.004 - 0.004, 0.0, 1.0) : 0.0;
        emissionMat *= emissionMat;

        porosity = specularMap.b <= 0.251 ? specularMap.b * 3.984 : 0.0;
        subsurface = specularMap.b > 0.251 ? clamp(specularMap.b * 1.335 - 0.355, 0.0, 1.0) : 0.0;

        #ifdef PARALLAX
        normalMap = vec3(texture2DGradARB(normals, newCoord, dcdx, dcdy).xy, 0.0) * 2.0 - 1.0;
        ao = texture2DGradARB(normals, newCoord, dcdx, dcdy).z;
        #else
        normalMap = vec3(texture2D(normals, texCoord).xy, 0.0) * 2.0 - 1.0;
        ao = texture2D(normals, texCoord).z;
        #endif

        if (normalMap.x + normalMap.y > -1.999) {
            if (length(normalMap.xy) > 1.0) normalMap.xy = normalize(normalMap.xy);
            normalMap.z = sqrt(1.0 - dot(normalMap.xy, normalMap.xy));
            normalMap = normalize(clamp(normalMap, vec3(-1.0), vec3(1.0)));
        }else{
            normalMap = vec3(0.0, 0.0, 1.0);
            ao = 1.0;
        }
        #endif

        #if EMISSIVE == 2
        emission = mix(emissionMat, 1.0, emission);
        #else
        emission = emissionMat;
        #endif

        #ifdef NORMAL_DAMPENING
        mipx = dcdx * atlasSize;
        mipy = dcdy * atlasSize;
        mipDelta = max(dot(mipx, mipx), dot(mipy, mipy));
        miplevel = max(0.25 * log2(mipDelta), 0.0);

        normalMap = normalize(mix(vec3(0.0, 0.0, 1.0), normalMap, 1.0 / exp2(miplevel)));
    #endif



    #if MATERIAL_FORMAT == 2
        vec4 specularMap = texture2DLod(specular, newCoord, 0);
        smoothness = specularMap.r;

        f0 = specularMap.g;
        metalness = f0 >= 0.9 ? 1.0 : 0.0;

        emissionMat = specularMap.a < 1.0 ? clamp(specularMap.a * 1.004 - 0.004, 0.0, 1.0) : 0.0;
        emissionMat *= emissionMat;

        porosity = specularMap.b <= 0.251 ? specularMap.b * 3.984 : 0.0;
        subsurface = specularMap.b > 0.251 ? clamp(specularMap.b * 1.335 - 0.355, 0.0, 1.0) : 0.0;

        #ifdef PARALLAX
        normalMap = vec3(texture2DGradARB(normals, newCoord, dcdx, dcdy).xy, 0.0) * 2.0 - 1.0;
        ao = texture2DGradARB(normals, newCoord, dcdx, dcdy).z;
        #else
        normalMap = vec3(texture2D(normals, texCoord).xy, 0.0) * 2.0 - 1.0;
        ao = texture2D(normals, texCoord).z;
        #endif

        if (normalMap.x + normalMap.y > -1.999) {
            if (length(normalMap.xy) > 1.0) normalMap.xy = normalize(normalMap.xy);
            normalMap.z = sqrt(1.0 - dot(normalMap.xy, normalMap.xy));
            normalMap = normalize(clamp(normalMap, vec3(-1.0), vec3(1.0)));
        }else{
            normalMap = vec3(0.0, 0.0, 1.0);
            ao = 1.0;
        }
        #endif

        #if EMISSIVE == 2
        emission = mix(emissionMat, 1.0, emission);
        #else
        emission = emissionMat;
        #endif

        #ifdef NORMAL_DAMPENING
        mipx = dcdx * atlasSize;
        mipy = dcdy * atlasSize;
        mipDelta = max(dot(mipx, mipx), dot(mipy, mipy));
        miplevel = max(0.25 * log2(mipDelta), 0.0);

        normalMap = normalize(mix(vec3(0.0, 0.0, 1.0), normalMap, 1.0 / exp2(miplevel)));
    #endif

}