public static RectNode CreateBspTree(Rect fullRect, int threshold, float minSplitRatio, float maxSplitRatio)
{
Debug.Assert(threshold > 0, "BSP threshold should be positive.");
Debug.Assert(minSplitRatio >= 0.0f && minSplitRatio <= 1.0f, "BSP min split ratio should be between 0.0 to 1.0.");
Debug.Assert(maxSplitRatio >= 0.0f && maxSplitRatio <= 1.0f, "BSP max split ratio should be between 0.0 to 1.0.");
Debug.Assert(minSplitRatio <= maxSplitRatio, "BSP min split ratio should be less than max.");
RectNode root = new RectNode(fullRect, null, null);
Stack <RectNode> nodeStack = new Stack <RectNode>();
nodeStack.Push(root);
while (nodeStack.Count > 0)
{
RectNode node = nodeStack.Pop();
Rect nodeRect = node.Rect;
if (nodeRect.Width <= threshold || nodeRect.Height <= threshold)
{
continue;
}
Rect rectLeft = new Rect();
Rect rectRight = new Rect();
float splitRatio = Random.Range(minSplitRatio, maxSplitRatio);
if (nodeRect.Width >= nodeRect.Height)
{
// Split horizontally
int leftWidth = Mathf.FloorToInt(nodeRect.Width * splitRatio);
int2 rightPos = nodeRect.LowerLeftPos + new int2(leftWidth, 0);
rectLeft.SetRect(nodeRect.LowerLeftPos, leftWidth, nodeRect.Height);
rectRight.SetRect(rightPos, nodeRect.Width - leftWidth, nodeRect.Height);
}
else
{
// Split vertically
int lowerHeight = Mathf.FloorToInt(nodeRect.Height * splitRatio);
int2 upperPos = nodeRect.LowerLeftPos + new int2(0, lowerHeight);
rectLeft.SetRect(nodeRect.LowerLeftPos, nodeRect.Width, lowerHeight);
rectRight.SetRect(upperPos, nodeRect.Width, nodeRect.Height - lowerHeight);
}
node.LeftNode = new RectNode(rectLeft, null, null);
node.RightNode = new RectNode(rectRight, null, null);
nodeStack.Push(node.LeftNode);
nodeStack.Push(node.RightNode);
}
return(root);
}
public RectNode GetRandomLeaf()
{
RectNode leaf = null;
Stack <RectNode> nodeStack = new Stack <RectNode>();
nodeStack.Push(this);
while (nodeStack.Count > 0)
{
RectNode node = nodeStack.Pop();
if (node.LeftNode == null && node.RightNode == null)
{
leaf = node;
break;
}
RectNode randomNode = Random.value > 0.5f ? node.LeftNode : node.RightNode;
nodeStack.Push(randomNode);
}
return(leaf);
}
public List <RectNode> GetLeafs()
{
List <RectNode> leafs = new List <RectNode>();
Stack <RectNode> nodeStack = new Stack <RectNode>();
nodeStack.Push(this);
while (nodeStack.Count > 0)
{
RectNode node = nodeStack.Pop();
if (node.LeftNode == null && node.RightNode == null)
{
leafs.Add(node);
continue;
}
nodeStack.Push(node.LeftNode);
nodeStack.Push(node.RightNode);
}
return(leafs);
}
public RectNode(Rect rect, RectNode leftNode, RectNode rightNode)
{
Rect = rect;
LeftNode = leftNode;
RightNode = rightNode;
}