public CSG Intersect(CSG csg)
{
Node a = new Node(this.Clone().polygons);
Node b = new Node(csg.Clone().polygons);
a.Invert();
b.ClipTo(a);
b.Invert();
a.ClipTo(b);
b.ClipTo(a);
a.Build(b.AllPolygons.ToList());
a.Invert();
return CSG.FromPolygons(a.AllPolygons);
}
public void Build(List<Polygon> polygons)
{
//Debug.Log("node:build started, polycount " + polygons.Count);
if (polygons.Count == 0)
{
//Debug.Log("node:build no polys, returning");
return;
}
if (this.plane == null) this.plane = polygons[0].Plane.Clone();
List<Polygon> front = new List<Polygon>();
List<Polygon> back = new List<Polygon>();
for (int i = 0; i < polygons.Count; i++)
{
this.plane.SplitPolygon(polygons[i], ref this.polygons, ref this.polygons, ref front, ref back);
}
//Debug.Log("node:build front length: " + front.Count + " back length " + back.Count);
if (front.Count > 0)
{
if (this.front == null) this.front = new Node();
this.front.Build(front);
}
if (back.Count > 0)
{
if (this.back == null) this.back = new Node();
this.back.Build(back);
}
}
/// <summary>
/// Convert solid space to empty space and empty space to solid space.
/// </summary>
public void Invert()
{
for (int i = 0; i < polygons.Count; i++)
{
this.polygons[i].Flip();
}
this.plane.Flip();
if (this.front != null) this.front.Invert();
if (this.back != null) this.back.Invert();
Node temp = this.front;
this.front = this.back;
this.back = temp;
}
public Node Clone()
{
Node node = new Node();
node.plane = this.plane;
node.front = this.front;
node.back = this.back;
node.polygons = this.polygons;
return node;
}
public void ClipTo(Node bsp)
{
this.polygons = bsp.ClipPolygons(this.polygons.ToArray());
if (this.front != null) this.front.ClipTo(bsp);
if (this.back != null) this.back.ClipTo(bsp);
}
// TODO: Check this function
/// <summary>
/// Recursively remove all polygons in `polygons` that are inside this BSP tree.
/// </summary>
public List<Polygon> ClipPolygons(Polygon[] polygons)
{
if (this.plane == null)
{
return polygons.Clone<Polygon>().ToList();
} // TODO: Removed slice here?
List<Polygon> front = new List<Polygon>();
List<Polygon> back = new List<Polygon>();
for (int i = 0; i < polygons.Length; i++)
{
this.plane.SplitPolygon(polygons[i], ref front, ref back, ref front, ref back);
}
if (this.front != null)
{
front = this.front.ClipPolygons(front.ToArray());
}
if (this.back != null)
{
back = this.back.ClipPolygons(back.ToArray());
}
else back = new List<Polygon>();
return front.Concat(back).ToList();
}
