/**
* 对当前节点进行递归分解 当分割一个节点时存在三种可能： 1、节点是钻石的一部分---分割它和它的下邻节点。 2、节点是网格的边---只分割这个节点。
* 3、节点不是钻石的一部分---强制分割下邻节点。
*
* @param node
*/
public void split(TriTreeNode node) {
// 如果已经切割，无需再处理
if (node.leftChild != null) return;
// 如果节点不是钻石的一部分---强制分割下邻节点
if (node.baseNeighbor != null && node.baseNeighbor.baseNeighbor != node)
split(node.baseNeighbor);
// 分配
node.leftChild = allocate();
node.rightChild = allocate();
// 如果分配库存已经用空
if (node.leftChild == null) return;
// 关联节点
node.leftChild.baseNeighbor = node.leftNeighbor;
node.leftChild.leftNeighbor = node.rightChild;
node.rightChild.baseNeighbor = node.rightNeighbor;
node.rightChild.rightNeighbor = node.leftChild;
if (node.leftNeighbor != null) {
if (node.leftNeighbor.baseNeighbor == node) node.leftNeighbor.baseNeighbor = node.leftChild;
else if (node.leftNeighbor.leftNeighbor == node)
node.leftNeighbor.leftNeighbor = node.leftChild;
else if (node.leftNeighbor.rightNeighbor == node)
node.leftNeighbor.rightNeighbor = node.leftChild;
else ; // Illegal Left Neighbor!
}
if (node.rightNeighbor != null) {
if (node.rightNeighbor.baseNeighbor == node)
node.rightNeighbor.baseNeighbor = node.rightChild;
else if (node.rightNeighbor.rightNeighbor == node)
node.rightNeighbor.rightNeighbor = node.rightChild;
else if (node.rightNeighbor.leftNeighbor == node)
node.rightNeighbor.leftNeighbor = node.rightChild;
else ; // Illegal Right Neighbor!
}
// 如果节点是钻石的一部分
if (node.baseNeighbor != null) {
// 如果已经切割，关联节点
if (node.baseNeighbor.leftChild != null) {
node.baseNeighbor.leftChild.rightNeighbor = node.rightChild;
node.baseNeighbor.rightChild.leftNeighbor = node.leftChild;
node.leftChild.rightNeighbor = node.baseNeighbor.rightChild;
node.rightChild.leftNeighbor = node.baseNeighbor.leftChild;
}
// 否则下邻节点。
else split(node.baseNeighbor);
} else {
// 是一个边缘节点，清空
node.leftChild.rightNeighbor = null;
node.rightChild.leftNeighbor = null;
}
// System.out.println("split "+node);
}
public void reset() {
visible = false;
baseLeft.leftChild = null;
baseLeft.rightChild = null;
baseRight.leftChild = null;
baseRight.rightChild = null;
baseLeft.baseNeighbor = baseRight;
baseRight.baseNeighbor = baseLeft;
baseLeft.rightNeighbor = null;
baseLeft.leftNeighbor = null;
baseRight.rightNeighbor = null;
baseRight.leftNeighbor = null;
}
public void init(int x, int y) {
// 清空记录
baseLeft.rightNeighbor = null;
baseLeft.leftNeighbor = null;
baseLeft.leftChild = null;
baseLeft.rightChild = null;
baseRight.rightNeighbor = null;
baseRight.leftNeighbor = null;
baseRight.leftChild = null;
baseRight.rightChild = null;
// 关联两个三角形
baseLeft.baseNeighbor = baseRight;
baseRight.baseNeighbor = baseLeft;
this.x = x;
this.y = y;
dirty = true;
}
private TriTreeNode allocate() {
if (nextTriNode >= POOL_SIZE) return null;
TriTreeNode node = pool[nextTriNode++];
node.leftChild = node.rightChild = null;
return node;
}
