//---------------------------------------
// Sphere v Frustum
//---------------------------------------
int Intersection::Test( const Spheref& sphere, const Frustum& frustum )
{
	// 1, 0, -1 : inside, intersect, outside
	int res = 1;
	for ( int i = 0; i < 6; ++i )
	{
		float dist = frustum.GetPlane( i ).DistanceTo( sphere.Center );
		if ( dist < -sphere.Radius )
		{
			return -1;
		}
		if ( dist < sphere.Radius )
		{
			res = 0;
		}
	}
	return res;
}