// Returns a random point on the surface of this shape
Point Sphere::GetRandomPointOnSurface(RNG& rng) const {
// Keep generating random coordinates within cube around unit sphere
// Reject any points outside the unit sphere
float x = 1.f - 2.f * rng.Random();
float y = 1.f - 2.f * rng.Random();
float z = 1.f - 2.f * rng.Random();
float lengthSquared = x*x + y*y + z*z;
// Expected number of iterations < 2
while (lengthSquared > 1.f) {
x = 1.f - 2.f * rng.Random();
y = 1.f - 2.f * rng.Random();
z = 1.f - 2.f * rng.Random();
lengthSquared = x*x + y*y + z*z;
}
// Point on surface of sphere
float invLength = 1.f / sqrtf(lengthSquared);
Point p(x, y, z);
return p * r * invLength + c;
}
