#include <common/lighting/brdf>
#include <common/lighting/attenuation>
#include <common/lighting/functions>

bool CCSurfacesLightingEnableShadow(in float NoL)
{
  return NoL > 0.0;
}

float CCSurfacesLightingCalculateDistanceAttenuation(in LightingIntermediateData lightingData, in vec4 lightSizeRangeAngle, in float lightType)
{
  return CalculateDistanceAttenuation(lightingData.distToLightSqr, lightSizeRangeAngle.x, lightSizeRangeAngle.y, lightType);
}

float CCSurfacesLightingCalculateAngleAttenuation(in LightingIntermediateData lightingData, in vec4 lightSizeRangeAngle, in vec3 spotLightDir)
{
  return CalculateAngleAttenuation(spotLightDir, lightingData.L, lightSizeRangeAngle.z);
}

void CCSurfacesLightingCalculateDirect(out vec3 lightingDiffuse, out vec3 lightingSpecular, in LightingIntermediateData lightingData, in vec4 lightSourceColorAndIntensity)
{
    vec3 irradiance = lightSourceColorAndIntensity.rgb * lightSourceColorAndIntensity.w;

    lightingDiffuse = irradiance; // no energy conservation

  // punctual lighting is different from dir lighting
#if CC_FORWARD_ADD
    float NL = 0.5 * lightingData.NoL + 0.5;
    lightingDiffuse *= NL;
#endif

    float NH = 0.5 * lightingData.NoH + 0.5;
    float specularWeight = 1.0 - pow(lightingData.specularParam, 5.0);
    float specularMask = step(specularWeight + EPSILON_LOWP, NH);
    lightingSpecular = irradiance * specularMask;
}

void CCSurfacesLightingCalculateEnvironment(out vec3 lightingDiffuse, out vec3 lightingSpecular, in LightingIntermediateData lightingData, float lightIntensity)
{
  lightingDiffuse = vec3(0.0);
  lightingSpecular = vec3(0.0);
}


#if CC_SURFACES_LIGHTING_USE_FRESNEL
vec3 CCSurfaceLightingCalculateExtraFresnel(in LightingIntermediateData lightingData)
{
    return vec3(1.0);
}
#endif

void CCSurfaceLightingCalculateDirectFresnel(out vec3 fresnel, in LightingIntermediateData lightingData, vec3 specularColor, in vec3 environmentGF)
{
    fresnel = vec3(1.0);
}

void CCSurfaceLightingCalculateEnvironmentFresnel(out vec3 integratedGF, out vec3 integratedF, in LightingIntermediateData lightingData, vec3 specularColor)
{
  integratedF = integratedGF = vec3(1.0);
}