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/**
* @file lightFuncV.glsl
*
* Copyright (c) 2007-$CurrentYear$, Linden Research, Inc.
* $License$
*/
float calcDirectionalLight(vec3 n, vec3 l)
{
float a = max(dot(n,l),0.0);
return a;
}
float calcPointLightOrSpotLight(vec3 v, vec3 n, vec4 lp, vec3 ln, float la, float is_pointlight)
{
//get light vector
vec3 lv = lp.xyz-v;
//get distance
float d = length(lv);
//normalize light vector
lv *= 1.0/d;
//distance attenuation
float da = clamp(1.0/(la * d), 0.0, 1.0);
// spotlight coefficient.
float spot = max(dot(-ln, lv), is_pointlight);
da *= spot*spot; // GL_SPOT_EXPONENT=2
//angular attenuation
da *= calcDirectionalLight(n, lv);
return da;
}
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