Flash里的 A* Pathfinding -- 详细代码及说明
在家上网赚钱更容易
//code by 月光 2005.9.22
//地图长宽
var mapx = 40;
var mapy = 40;
var total = mapx * mapy;
//边界距离
var distancex = 30;
var distancey = 30;
//移动速度
var interval = 75;
//初始障碍物比率
var balk = 3;
var val;
var width = 0;
var height = 0;
//移动次数
var moves = 0;
//是否正在忙碌
var busy = false;
//是否正在移动
var moving = false;
//是否搜索成功
var finded = false;
//路径记录
var open = new Array();
//方向数组 => 右, 下, 左, 上
var ori = new Array([1, 0], [0, 1], [-1, 0], [0, -1]);
// ========================================
//重置
var reset = function () {
?clearInterval(val);
?for (var i in _root) {
? if (typeof _root[i] == "movieclip") {
?? _root[i].removeMovieClip();
? }
?}
?txt.text = "";
?init();
};
btn_reset.onPress = reset;
// ========================================
//初始化
var init = function () {
?var i = 1;
?// 绘制地图
?while (i <= total) {
? var tmp = attachMovie("mc", "m" + i, i, {id:i, visited:false});
? tmp._x = (i - 1) % mapx * tmp._width + distancex;
? tmp._y = Math.floor((i - 1) / mapy) * tmp._height + distancey;
? if (random(balk) == 0) {
?? tmp.gotoAndStop(2);
? }
? i++;
?}
?m1.gotoAndStop(1);
?width = m1._width;
?height = m1._height;
?// 主角初始位置
?attachMovie("player", "player", total + 10000, {_x:distancex, _y:distancey});
?player.onPress = function() {
? busy = true;
? txt.text = "请选择目标";
?};
?moving = false;
};
// ========================================
//点击地图后执行
btn.onPress = function() {
?if (!moving) {
? var i = 1;
? while (i <= total) {
?? this._parent["m" + i].visited = false;
?? i++;
? }
? var x = Math.ceil((_xmouse - distancex) / width);
? var y = Math.ceil((_ymouse - distancey) / height);
? var id = x + (y - 1) * mapy;
? //当前点击的MC
? var tmp = this._parent["m" + id];
? if (!busy) {
?? if (tmp._currentframe == 1) {
??? txt.text = "目标转换为障碍物";
??? tmp.gotoAndStop(2);
?? } else {
??? txt.text = "目标转换为通道";
??? tmp.gotoAndStop(1);
?? }
? } else {
?? if (tmp._currentframe == 2) {
??? txt.text = "目标为障碍物,无法到达";
??? busy = false;
?? } else {
??? findit(x, y);
?? }
? }
?}
};
// ========================================
//寻路
var findit = function (x, y) {
?finded = false;
?open = new Array();
?var playerx = Math.ceil((player._x - distancex) / width) + 1;
?var playery = Math.ceil((player._y - distancey) / height) + 1;
?moves = 1;
?// 数组内元素为: X坐标, Y坐标, 距离原点长度, 上级位置
?open[1] = [x, y, moves, 1];
?for (i = 0; i < 4; i++) {
? // 邻格内移动
? if (x + ori[i][0] == playerx && y + ori[i][1] == playery) {
?? movefunc();
?? return;
? }
?}
?// 非邻格内移动
?var z = 1;
?var t = 1;
?while (open[z] != null) {
? for (i = 0; i < 4; i++) {
?? var tmpx = open[z][0] + ori[i][0];
?? var tmpy = open[z][1] + ori[i][1];
?? if (tmpx > 0 && tmpy > 0 && tmpx <= 40 && tmpy <= 40) {
??? var id = tmpx + (tmpy - 1) * mapy;
??? var tmp = this["m" + id];
??? // 当对象存在及非障碍物及未访问过时
??? if (tmp != null && tmp._currentframe == 1 && !tmp.visited) {
???? tmp.visited = true;
???? open[++t] = [tmpx, tmpy, open[z][2] + 1, z];
???? if (open[t][0] == playerx && open[t][1] == playery) {
????? finded = true;
????? moves = z;
????? break;
???? }
??? }
?? }
? }
? z++;
?}
?if (finded) {
? movefunc();
?} else {
? busy = false;
? moving = false;
? //debug
? trace(open.join(" => "));
? txt.text = "无法到达目标";
?}
};
// ========================================
//角色移动
var movefunc = function () {
?moving = true;
?txt.text = "找到目标,正在移动";
?val = setInterval(moveFunc, interval);
};
var moveFunc = function () {
?updateAfterEvent();
?moves = open[moves][3];
?player._x = (open[moves][0] - 1) * width + distancex;
?player._y = (open[moves][1] - 1) * height + distancey;
?if (moves == 1) {
? busy = moving = finded = false;
? txt.text = "已到达目标";
? clearInterval(val);
?}
};
// ========================================
init();
stop();
本帖参考自OReilly的AI for Game Developers这本书的第七章A* Pathfinding,推荐对游戏开发有兴趣的朋友们可以找来研究下.
?
关于A*算法,也叫A STAR,这里有篇国人翻译的文章:
http://blog.vckbase.com/panic/archive/2005/03/20/3778.html
英文原文地址:
http://www.gamedev.net/reference/articles/article2003.asp
原帖地址:
http://www.blueidea.com/bbs/newsdetail.asp?id=2376491
