Exemple #1
0
RADENG_API bool RADENG_CALL RayIntersectsBBox(const Vec3 &_a, const Vec3 &_b, const BBox &bounds) {
	Vec3 a(_a);
	Vec3 b(_b);
	Plane::SideType sides[2];

	for (int i = 0; i < 2; ++i) {
		for (int k = 0; k < 3; ++k) {
			Vec3 normal(Vec3::Zero);
			normal[k] = (i == 0) ? -1.f : 1.f;

			Plane plane(normal, (i==0) ? -bounds.Mins()[k] : bounds.Maxs()[k]);
			sides[0] = plane.Side(a, 0.f);
			sides[1] = plane.Side(b, 0.f);

			if (sides[0] == Plane::On)
				sides[0] = sides[1];
			if (sides[1] == Plane::On)
				sides[1] = sides[0];

			if (((sides[0] == Plane::On) || (sides[0] == Plane::Front)) && (sides[0] == sides[1]))
				return false; // all on front

			if (sides[0] != sides[1]) {
				// cross
				Vec3 mid;
				plane.IntersectLineSegment(mid, a, b, 0.f);
				if (sides[0] == Plane::Front) {
					a = mid;
				} else {
					RAD_ASSERT(sides[1] == Plane::Front);
					b = mid;
				}
			}
		}
	}
	
	// ray passes through bbox
	return true;
}