public Vector GetSamplePoint(Sampler random)
{
// get two randoms
float sqr1 = (float)Math.Sqrt(random.GetNextSample());
float r2 = (float)random.GetNextSample();
// make barycentric coords
float a = 1.0f - sqr1;
float b = (1.0f - r2) * sqr1;
// make position from barycentrics
// calculate interpolation by using two edges as axes scaled by the
// barycentrics
return edge1 * a + edge2 * b + verts[0];
}
public void GetEmitter(Sampler random, out Vector position, out Triangle triangle)
{
if (emitters.Count != 0)
{
// select emitter
// not using lower bits, by treating the random as fixed-point i.f bits
int index = ((((int)(int.MaxValue*random.GetNextSample()) & ((1 << MAX_EMITTERS_P) - 1)) * emitters.Count) >> MAX_EMITTERS_P);
// get position on triangle
position = emitters[index].GetSamplePoint(random);
triangle = emitters[index];
}
else
{
position = Vector.ZERO;
triangle = null;
}
}
