Files
esengine/source/src/AI/Pathfinding/AStar/AstarGridGraph.ts
T
2020-07-09 16:36:42 +08:00

72 lines
2.1 KiB
TypeScript

/**
* 基本静态网格图与A*一起使用
* 将walls添加到walls HashSet,并将加权节点添加到weightedNodes
*/
class AstarGridGraph implements IAstarGraph<Vector2> {
public dirs: Vector2[] = [
new Vector2(1, 0),
new Vector2(0, -1),
new Vector2(-1, 0),
new Vector2(0, 1)
];
public walls: Vector2[] = [];
public weightedNodes: Vector2[] = [];
public defaultWeight: number = 1;
public weightedNodeWeight = 5;
private _width;
private _height;
private _neighbors: Vector2[] = new Array(4);
constructor(width: number, height: number){
this._width = width;
this._height = height;
}
/**
* 确保节点在网格图的边界内
* @param node
*/
public isNodeInBounds(node: Vector2): boolean {
return 0 <= node.x && node.x < this._width && 0 <= node.y && node.y < this._height;
}
/**
* 检查节点是否可以通过。walls是不可逾越的。
* @param node
*/
public isNodePassable(node: Vector2): boolean {
return !this.walls.firstOrDefault(wall => JSON.stringify(wall) == JSON.stringify(node));
}
/**
* 调用AStarPathfinder.search的快捷方式
* @param start
* @param goal
*/
public search(start: Vector2, goal: Vector2){
return AStarPathfinder.search(this, start, goal);
}
public getNeighbors(node: Vector2): Vector2[] {
this._neighbors.length = 0;
this.dirs.forEach(dir => {
let next = new Vector2(node.x + dir.x, node.y + dir.y);
if (this.isNodeInBounds(next) && this.isNodePassable(next))
this._neighbors.push(next);
});
return this._neighbors;
}
public cost(from: Vector2, to: Vector2): number {
return this.weightedNodes.find((p)=> JSON.stringify(p) == JSON.stringify(to)) ? this.weightedNodeWeight : this.defaultWeight;
}
public heuristic(node: Vector2, goal: Vector2) {
return Math.abs(node.x - goal.x) + Math.abs(node.y - goal.y);
}
}