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#ifndef UNITY_COMMON_LIGHTING_INCLUDED
#define UNITY_COMMON_LIGHTING_INCLUDED
#include "Common.hlsl"
//-----------------------------------------------------------------------------
// Attenuation functions
//-----------------------------------------------------------------------------
// Ref: Moving Frostbite to PBR
float SmoothDistanceAttenuation(float squaredDistance, float invSqrAttenuationRadius)
{
float factor = squaredDistance * invSqrAttenuationRadius;
float smoothFactor = saturate(1.0f - factor * factor);
return smoothFactor * smoothFactor;
}
#define PUNCTUAL_LIGHT_THRESHOLD 0.01 // 1cm (in Unity 1 is 1m)
float GetDistanceAttenuation(float3 unL, float invSqrAttenuationRadius)
{
float sqrDist = dot(unL, unL);
float attenuation = 1.0f / (max(PUNCTUAL_LIGHT_THRESHOLD * PUNCTUAL_LIGHT_THRESHOLD, sqrDist));
// Non physically based hack to limit light influence to attenuationRadius.
attenuation *= SmoothDistanceAttenuation(sqrDist, invSqrAttenuationRadius);
return attenuation;
}
float GetAngleAttenuation(float3 L, float3 lightDir, float lightAngleScale, float lightAngleOffset)
{
float cd = dot(lightDir, L);
float attenuation = saturate(cd * lightAngleScale + lightAngleOffset);
// smooth the transition
attenuation *= attenuation;
return attenuation;
}
#endif // UNITY_COMMON_LIGHTING_INCLUDED