// Return a new CSG solid representing space in either this solid or in the
// solid `csg`. Neither this solid nor the solid `csg` are modified.
public static csgjs_csgnode csg_union(csgjs_csgnode a1, csgjs_csgnode b1)
{
csgjs_csgnode a = a1.clone();
csgjs_csgnode b = b1.clone();
a.clipTo(b);
b.clipTo(a);
b.invert();
b.clipTo(a);
b.invert();
a.build(b.allPolygons());
csgjs_csgnode ret = new csgjs_csgnode(a.allPolygons());
a = null;
b = null;
return(ret);
}
// Build a BSP tree out of `polygons`. When called on an existing tree, the
// new polygons are filtered down to the bottom of the tree and become new
// nodes there. Each set of polygons is partitioned using the first polygon
// (no heuristic is used to pick a good split).
void build(List <csgjs_polygon> list)
{
if (list.Count == 0)
{
return;
}
if (!plane.ok())
{
plane = list[0].plane;
}
List <csgjs_polygon> list_front = new List <csgjs_polygon>();
List <csgjs_polygon> list_back = new List <csgjs_polygon>();
for (int i = 0; i < list.Count; i++)
{
plane.splitPolygon(list[i], polygons, polygons, ref list_front, ref list_back);
}
if (list_front.Count > 0)
{
if (front == null)
{
front = new csgjs_csgnode();
}
front.build(list_front);
}
if (list_back.Count > 0)
{
if (back == null)
{
back = new csgjs_csgnode();
}
back.build(list_back);
}
}
