closest to line.java

Entity closestToRay(Vector3 a, Vector3 b, Iterable<Entity> list) {
	if(a.equals(b)) return closestToPoint(a, list);
	Vec3d start   = a.toVec3D();
	Vec3d offset  = b.toVec3D().subtract(start);
	Vec3d diff    = offset.normalize();
	double minDot = diff.dotProduct(offset);

	double minDist = Double.MAX_VALUE;
	Entity found = null;

	for(Entity e : list) {
		Vec3d pos = entity.getPositionVector().subtract(start);
		double dot = diff.dotProduct(pos);
		double dist;
		if(dot <= minDot) dist = pos.length();
		else              dist = pos.crossProduct(diff).length();

		if(dist < minDist) {
			minDist = dist;
			found = e;
		}
	}
	if(found == null)
		throw new RuntimeException("fuck");
	return found;
}

Entity closestToLineSegment(Vector3 a, Vector3 b, Iterable<Entity> list) {
	if(a.equals(b)) return closestToPoint(a, list);
	Vec3d start   = a.toVec3D();
	Vec3d end     = b.toVec3D();
	Vec3d diff    = end.subtract(start).normalize();
	double minDot = diff.dotProduct(start);
	double maxDot = diff.dotProduct(end);

	double minDist = Double.MAX_VALUE;
	Entity found = null;

	for(Entity e : list) {
		Vec3d pos = entity.getPositionVector();
		double dot = diff.dotProduct(pos);
		double dist;
		if(dot <= minDot)      dist = pos.subtract(start).length();
		else if(dot >= maxDot) dist = pos.subtract(end).length();
		else                   dist = pos.subtract(start).crossProduct(diff).length();

		if(dist < minDist) {
			minDist = dist;
			found = e;
		}
	}
	if(found == null)
		throw new RuntimeException("fuck");
	return found;
}

Entity closestToLine(Vector3 a, Vector3 b, Iterable<Entity> list) {
	if(a.equals(b)) return closestToPoint(a, list);
	Vec3d start = a.toVec3D();
	Vec3d diff  = b.toVec3D().subtract(start).normalize();

	double minDist = Double.MAX_VALUE;
	Entity found = null;

	for(Entity e : list) {
		Vec3d pos = entity.getPositionVector();
		double dist = pos.subtract(start).crossProduct(diff).length();

		if(dist < minDist) {
			minDist = dist;
			found = e;
		}
	}
	if(found == null)
		throw new RuntimeException("fuck");
	return found;
}