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implementing fcpw;
__include ray;
__include math_constants;
__include interaction;
__include bounding_volumes;
public float3x3 extractLinearTransform(float3x4 t)
{
return float3x3(t[0].xyz, t[1].xyz, t[2].xyz);
}
public float3 extractTranslation(float3x4 t)
{
return float3(t[0][3], t[1][3], t[2][3]);
}
public float3 transformPoint(float3x4 t, float3 p)
{
return mul(t, float4(p, 1.0)).xyz;
}
public Ray transformRay(float3x4 t, Ray r)
{
float3 o = transformPoint(t, r.o);
float3 d = transformPoint(t, r.o + r.d * (r.tMax < FLT_MAX ? r.tMax : 1.0)) - o;
float dNorm = length(d);
return Ray(o, d / dNorm, r.tMax < FLT_MAX ? dNorm : FLT_MAX);
}
public BoundingSphere transformSphere(float3x4 t, BoundingSphere s)
{
float3 c = transformPoint(t, s.c);
float r2 = FLT_MAX;
if (s.r2 < FLT_MAX)
{
float3 d = transformPoint(t, s.c + float3(sqrt(s.r2), 0.0, 0.0)) - c;
r2 = dot(d, d);
}
return BoundingSphere(c, r2);
}
public void transformInteraction(float3x4 t, float3x4 tInv, float3 x,
bool overwriteDistance, inout Interaction i)
{
float3 p = transformPoint(t, i.p);
float3 n = normalize(mul(transpose(extractLinearTransform(tInv)), i.n));
i.p = p;
i.n = n;
if (overwriteDistance)
{
i.d = length(p - x);
}
}
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