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const int MAX_LIGHTS = 8;
const int TYPE_POINT = 0;
const int TYPE_DIRECTIONAL = 1;
const int TYPE_SPOT = 2;
struct Light {
int type;
vec3 position;
vec3 color;
float intensity;
vec3 direction;
float constantAttenuation;
float linearAttenuation;
float quadraticAttenuation;
float cutOffAngle;
};
uniform Light lights[MAX_LIGHTS];
uniform int lightCount;
// Pre-convolved environment maps
struct EnvironmentLight {
samplerCube irradiance; // For diffuse contribution
samplerCube specular; // For specular contribution
};
uniform EnvironmentLight envLight;
uniform int envLightCount = 0;
void adsModel(const in vec3 worldPos,
const in vec3 worldNormal,
const in vec3 worldView,
const in float shininess,
out vec3 diffuseColor,
out vec3 specularColor)
{
diffuseColor = vec3(0.0);
specularColor = vec3(0.0);
// We perform all work in world space
vec3 n = normalize(worldNormal);
vec3 s = vec3(0.0);
for (int i = 0; i < lightCount; ++i) {
float att = 1.0;
float sDotN = 0.0;
if (lights[i].type != TYPE_DIRECTIONAL) {
// Point and Spot lights
// Light position is already in world space
vec3 sUnnormalized = lights[i].position - worldPos;
s = normalize(sUnnormalized); // Light direction
// Calculate the attenuation factor
sDotN = dot(s, n);
if (sDotN > 0.0) {
if (lights[i].constantAttenuation != 0.0
|| lights[i].linearAttenuation != 0.0
|| lights[i].quadraticAttenuation != 0.0) {
float dist = length(sUnnormalized);
att = 1.0 / (lights[i].constantAttenuation +
lights[i].linearAttenuation * dist +
lights[i].quadraticAttenuation * dist * dist);
}
// The light direction is in world space already
if (lights[i].type == TYPE_SPOT) {
// Check if fragment is inside or outside of the spot light cone
if (degrees(acos(dot(-s, lights[i].direction))) > lights[i].cutOffAngle)
sDotN = 0.0;
}
}
} else {
// Directional lights
// The light direction is in world space already
s = normalize(-lights[i].direction);
sDotN = dot(s, n);
}
// Calculate the diffuse factor
float diffuse = max(sDotN, 0.0);
// Calculate the specular factor
float specular = 0.0;
if (diffuse > 0.0 && shininess > 0.0) {
float normFactor = (shininess + 2.0) / 2.0;
vec3 r = reflect(-s, n); // Reflection direction in world space
specular = normFactor * pow(max(dot(r, worldView), 0.0), shininess);
}
// Accumulate the diffuse and specular contributions
diffuseColor += att * lights[i].intensity * diffuse * lights[i].color;
specularColor += att * lights[i].intensity * specular * lights[i].color;
}
}
vec4 phongFunction(const in vec4 ambient,
const in vec4 diffuse,
const in vec4 specular,
const in float shininess,
const in vec3 worldPosition,
const in vec3 worldView,
const in vec3 worldNormal)
{
// Calculate the lighting model, keeping the specular component separate
vec3 diffuseColor, specularColor;
adsModel(worldPosition, worldNormal, worldView, shininess, diffuseColor, specularColor);
// Combine spec with ambient+diffuse for final fragment color
vec3 color = (ambient.rgb + diffuseColor) * diffuse.rgb
+ specularColor * specular.rgb;
return vec4(color, diffuse.a);
}
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