public void SplitByPlane(Plane plane, ref PolygonTreeNodeList coplanarfrontnodes, ref PolygonTreeNodeList coplanarbacknodes, ref PolygonTreeNodeList frontnodes, ref PolygonTreeNodeList backnodes)
{
if (children.Count > 0)
{
var queue = new Queue <PolygonTreeNodeList>();
queue.Enqueue(children);
while (queue.Count > 0)
{
var nodes = queue.Dequeue();
var l = nodes.Count;
for (int j = 0; j < l; j++)
{
var node = nodes[j];
if (node.children.Count > 0)
{
queue.Enqueue(node.children);
}
else
{
node.SplitPolygonByPlane(plane, ref coplanarfrontnodes, ref coplanarbacknodes, ref frontnodes, ref backnodes);
}
}
}
}
else
{
SplitPolygonByPlane(plane, ref coplanarfrontnodes, ref coplanarbacknodes, ref frontnodes, ref backnodes);
}
}
public PolygonTreeNode()
{
parent = null;
children = new PolygonTreeNodeList();
polygon = null;
removed = false;
}
public void AddPolygons(List <Polygon> polygons)
{
var n = polygons.Count;
var polygontreenodes = new PolygonTreeNodeList(n);
for (var i = 0; i < n; i++)
{
var p = polygonTree.AddChild(polygons[i]);
polygontreenodes.Add(p);
}
rootnode.AddPolygonTreeNodes(polygontreenodes);
}
public void ClipPolygons(PolygonTreeNodeList clippolygontreenodes, bool alsoRemoveCoplanarFront)
{
var args = new Args {
Node = this, PolygonTreeNodes = clippolygontreenodes
};
Stack <Args> stack = null;
while (args.Node != null)
{
var clippingNode = args.Node;
var polygontreenodes = args.PolygonTreeNodes;
if (clippingNode.Plane != null)
{
PolygonTreeNodeList backnodes = null;
PolygonTreeNodeList frontnodes = null;
var plane = clippingNode.Plane;
var numpolygontreenodes = polygontreenodes.Count;
for (var i = 0; i < numpolygontreenodes; i++)
{
var polyNode = polygontreenodes[i];
if (!polyNode.IsRemoved)
{
if (alsoRemoveCoplanarFront)
{
polyNode.SplitByPlane(plane, ref backnodes, ref backnodes, ref frontnodes, ref backnodes);
}
else
{
polyNode.SplitByPlane(plane, ref frontnodes, ref backnodes, ref frontnodes, ref backnodes);
}
}
}
if (clippingNode.Front != null && (frontnodes != null))
{
if (stack == null)
{
stack = new Stack <Args>();
}
stack.Push(new Args {
Node = clippingNode.Front, PolygonTreeNodes = frontnodes
});
}
var numbacknodes = backnodes == null ? 0 : backnodes.Count;
if (clippingNode.Back != null && (numbacknodes > 0))
{
if (stack == null)
{
stack = new Stack <Args>();
}
stack.Push(new Args {
Node = clippingNode.Back, PolygonTreeNodes = backnodes
});
}
else
{
// there's nothing behind this plane. Delete the nodes behind this plane:
for (var i = 0; i < numbacknodes; i++)
{
backnodes[i].Remove();
}
}
}
if (stack != null && stack.Count > 0)
{
args = stack.Pop();
}
else
{
args.Node = null;
}
}
}
public Node(Node parent)
{
PolygonTreeNodes = new PolygonTreeNodeList();
Parent = parent;
}
void SplitPolygonByPlane(Plane plane, ref PolygonTreeNodeList coplanarfrontnodes, ref PolygonTreeNodeList coplanarbacknodes, ref PolygonTreeNodeList frontnodes, ref PolygonTreeNodeList backnodes)
{
var polygon = this.polygon;
if (polygon != null)
{
var bound = polygon.BoundingSphere;
var sphereradius = bound.Radius + 1.0e-4;
var planenormal = plane.Normal;
var spherecenter = bound.Center;
var d = planenormal.Dot(spherecenter) - plane.W;
if (d > sphereradius)
{
if (frontnodes == null)
{
frontnodes = new PolygonTreeNodeList();
}
frontnodes.Add(this);
}
else if (d < -sphereradius)
{
if (backnodes == null)
{
backnodes = new PolygonTreeNodeList();
}
backnodes.Add(this);
}
else
{
SplitPolygonResult splitresult;
plane.SplitPolygon(polygon, out splitresult);
switch (splitresult.Type)
{
case 0:
if (coplanarfrontnodes == null)
{
coplanarfrontnodes = new PolygonTreeNodeList();
}
coplanarfrontnodes.Add(this);
break;
case 1:
if (coplanarbacknodes == null)
{
coplanarbacknodes = new PolygonTreeNodeList();
}
coplanarbacknodes.Add(this);
break;
case 2:
if (frontnodes == null)
{
frontnodes = new PolygonTreeNodeList();
}
frontnodes.Add(this);
break;
case 3:
if (backnodes == null)
{
backnodes = new PolygonTreeNodeList();
}
backnodes.Add(this);
break;
default:
if (splitresult.Front != null)
{
var frontnode = AddChild(splitresult.Front);
if (frontnodes == null)
{
frontnodes = new PolygonTreeNodeList();
}
frontnodes.Add(frontnode);
}
if (splitresult.Back != null)
{
var backnode = AddChild(splitresult.Back);
if (backnodes == null)
{
backnodes = new PolygonTreeNodeList();
}
backnodes.Add(backnode);
}
break;
}
}
}
}
public void AddPolygonTreeNodes(PolygonTreeNodeList addpolygontreenodes)
{
var args = new Args {
Node = this, PolygonTreeNodes = addpolygontreenodes
};
var stack = new Stack <Args>();
while (args.Node != null)
{
var node = args.Node;
var polygontreenodes = args.PolygonTreeNodes;
if (polygontreenodes.Count == 0)
{
// Nothing to do
}
else
{
var _this = node;
if (node.Plane == null)
{
var bestplane = polygontreenodes[0].GetPolygon().Plane;
node.Plane = bestplane;
}
var frontnodes = new PolygonTreeNodeList();
var backnodes = new PolygonTreeNodeList();
for (int i = 0, n = polygontreenodes.Count; i < n; i++)
{
polygontreenodes[i].SplitByPlane(_this.Plane, ref _this.PolygonTreeNodes, ref backnodes, ref frontnodes, ref backnodes);
}
if (frontnodes.Count > 0)
{
if (node.Front == null)
{
node.Front = new Node(node);
}
stack.Push(new Args {
Node = node.Front, PolygonTreeNodes = frontnodes
});
}
if (backnodes.Count > 0)
{
if (node.Back == null)
{
node.Back = new Node(node);
}
stack.Push(new Args {
Node = node.Back, PolygonTreeNodes = backnodes
});
}
}
if (stack.Count > 0)
{
args = stack.Pop();
}
else
{
args.Node = null;
}
}
}
public Args(Node node, PolygonTreeNodeList polygonTreeNodes)
{
Node = node;
PolygonTreeNodes = polygonTreeNodes;
}
public void AddPolygonTreeNodes(PolygonTreeNodeList addpolygontreenodes)
{
var args = new Args(node: this, polygonTreeNodes: addpolygontreenodes);
Stack <Args>?stack = null;
while (true)
{
var node = args.Node;
var polygontreenodes = args.PolygonTreeNodes;
if (polygontreenodes.Count == 0)
{
// Nothing to do
}
else
{
var _this = node;
var _thisPlane = _this.Plane;
if (_thisPlane == null)
{
var bestplane = polygontreenodes[0].GetPolygon().Plane;
node.Plane = bestplane;
_thisPlane = bestplane;
}
var frontnodes = default(PolygonTreeNodeList);
var backnodes = default(PolygonTreeNodeList);
for (int i = 0, n = polygontreenodes.Count; i < n; i++)
{
polygontreenodes[i].SplitByPlane(_thisPlane, ref _this.PolygonTreeNodes, ref backnodes, ref frontnodes, ref backnodes);
}
if (frontnodes != null && frontnodes.Count > 0)
{
if (node.Front == null)
{
node.Front = new Node(node);
}
if (stack == null)
{
stack = new Stack <Args> ();
}
stack.Push(new Args(node: node.Front, polygonTreeNodes: frontnodes));
}
if (backnodes != null && backnodes.Count > 0)
{
if (node.Back == null)
{
node.Back = new Node(node);
}
if (stack == null)
{
stack = new Stack <Args> ();
}
stack.Push(new Args(node: node.Back, polygonTreeNodes: backnodes));
}
}
if (stack != null && stack.Count > 0)
{
args = stack.Pop();
}
else
{
break;
}
}
}