/*
A library of lighting functions
January 19 2007

LightingUtils.h
*/

color plastic(normal n; 
			  vector i; 
			  float ka, kd, ks, roughness; 
			  color hilitecolor)
{
normal	nn = normalize(n);
vector ii = normalize(i);
normal	nf = faceforward(nn, ii);
color ambientcolor = ka * ambient();
color diffusecolor = kd * diffuse(nf);
color speccolor = ks * specular(nf, -ii, roughness) * hilitecolor;
return (ambientcolor + diffusecolor +speccolor);
}

color envmapping(normal norm;
                 vector incident;
                 string mapname;
                 string coordname;
                 float  kenv)
{
color envcolor = 0;
if(mapname != "")
    {
    normal    n = normalize(norm);
    vector    i = normalize(incident);
    normal    nf = faceforward(n, i);
    
    vector R = reflect(i, nf);
    R = transform(coordname, R);
    envcolor = environment(mapname, R) * kenv;
    }
return envcolor;
}