bool ServerEnvironment::line_of_sight(v3f pos1, v3f pos2, float stepsize, bool buildable_to, v3s16 *p)
{
	float distance = pos1.getDistanceFrom(pos2);

	//calculate normalized direction vector
	v3f normalized_vector = v3f((pos2.X - pos1.X)/distance,
		(pos2.Y - pos1.Y)/distance,
		(pos2.Z - pos1.Z)/distance);

	//find out if there's a node on path between pos1 and pos2
	for (float i = 1; i < distance; i += stepsize) {
		v3s16 pos = floatToInt(v3f(normalized_vector.X * i,
			normalized_vector.Y * i,
			normalized_vector.Z * i) +pos1,BS);

		MapNode n = getMap().getNodeNoEx(pos);

		if(n.drawtype != NDT_AIRLIKE) {
			if(buildable_to == true) {
				if(n.buildable_to == false) {
					if (p) {
						*p = pos;
					}
					return false;
				}
			}
			else
			{
				if (p) {
					*p = pos;
				}
				return false;
			}
		}
	}
	return true;
}