ActionScript 3.0 实现的A*寻路算法源代码
首先是文档类Index.as：
package code{ import flash.display.Sprite; import flash.text.TextField; import flash.text.TextFormat; public class Index extends Sprite{ private var road:Road; public function Index(){ stage.align = "TL"; stage.scaleMode = "noScale"; stage.showDefaultContextMenu = false; init(); } //初始化 private function init():void{ road = new Road; addChild(road); road.x = GV.ROAD_INIT_X; road.y = GV.ROAD_INIT_Y; //地图规格申明 var text:TextField = new TextField; text.htmlText = "地图规格：50*50方格，障碍物500方格 寻路算法：A*（星） 制作：sunbright"; addChild(text); text.x = 25; text.y = 530; text.width = 500; text.selectable = false; text.mouseEnabled = false; text.setTextFormat(new TextFormat("宋体",12,0xffffff)); text = null; } } }
定义参数的类：GV.as
package{ public class GV{ public function GV(){ throw new Error("变量"); } //Road创建的初始x、y坐标 public static const ROAD_INIT_X:int = 25; public static const ROAD_INIT_Y:int = 25; //纵横方块参数 public static const WIDTH_NUMBER:int = 50; public static const HEIGHT_NUMBER:int = 50; public static const WIDTH_TOTAL:int = 500; public static const HEIGHT_TOTAL:int = 500; public static const GRID_WIDTH:int = 10; public static const GRID_HEIGHT:int = 10; //障碍物个数 public static const THING_NUMBER:int = 500; //state状态参数表示 public static const HAVE_THING:int = 1; public static const IMPASSE_VALUE:int = 2; public static const MAIN_VALUE:int = 8; //路径耗费固定值 public static const BIAS_VALUE:int = 14; public static const LINE_VALUE:int = 10; //文本表示 public static const IMPASSE:String = "死路！"; public static const RESULT_FRONT:String = "用时 "; public static const RESULT_BACK:String = " 毫秒"; } }
主要算法所存在的Road.as类
package code{ import flash.display.Sprite; import flash.events.MouseEvent; import flash.text.TextField; import flash.text.TextFormat; import flash.utils.clearInterval; import flash.utils.getTimer; import flash.utils.setInterval; public class Road extends Sprite{ private var lands:Sprite; private var things:Sprite; private var c:Coordinate; private var main:Main; private var click:Sprite; private var drawPath:Sprite; private var result:TextField; private var unlockList:Array; private var lockList:Object; private var targetIX:int; private var targetIY:int; private var intervalID:int = 0; private var startTime:int; private var endTime:int; public function Road(){ init(); } //初始化 private function init():void{ //创建坐标 c = new Coordinate; //创建文本框 result = new TextField; result.mouseEnabled = false; result.autoSize = "left"; result.y = -20; result.selectable = false; result.defaultTextFormat = new TextFormat("宋体",12,0xffffff); addChild(result); result.text = "结果"; //创建平原 lands = new Sprite; lands.mouseChildren = false; lands.mouseEnabled = false; addChild(lands); lands.graphics.beginFill(0xff0000); lands.graphics.lineStyle(0); lands.graphics.drawRect(0,0,GV.WIDTH_TOTAL,GV.HEIGHT_TOTAL); for(var i:int = 1; i < GV.WIDTH_NUMBER; i ++){ lands.graphics.moveTo(GV.GRID_WIDTH * i,0); lands.graphics.lineTo(GV.GRID_WIDTH * i,GV.HEIGHT_TOTAL); lands.graphics.endFill(); lands.graphics.moveTo(0,GV.GRID_HEIGHT * i); lands.graphics.lineTo(GV.WIDTH_TOTAL,GV.GRID_HEIGHT * i); lands.graphics.endFill(); } //创建障碍层 things = new Sprite; things.mouseChildren = false; things.mouseEnabled = false; addChild(things); //创建路线绘制层 drawPath = new Sprite; addChild(drawPath); //创建操控人 main = new Main; addChild(main); //创建控制区 click = new Sprite; click.graphics.beginFill(0,0); click.graphics.drawRect(0,0,GV.WIDTH_TOTAL,GV.HEIGHT_TOTAL); addChild(click); click.addEventListener(MouseEvent.CLICK,clickHandle); //开始初始化 randomState(); createRoad(); } //随机生成障碍 private function randomState():void{ var ix:int; var iy:int; var i:int = 0; //随机障碍 while(i < GV.THING_NUMBER){ ix = int(Math.random() * GV.WIDTH_NUMBER); iy = int(Math.random() * GV.HEIGHT_NUMBER); if(c[ix][iy] == null){ i ++; c[ix][iy] = GV.HAVE_THING; } } //随机摆放操控人 while(true){ ix = int(Math.random() * GV.WIDTH_NUMBER); iy = int(Math.random() * GV.HEIGHT_NUMBER); if(c[ix][iy] == null){ c[ix][iy] = GV.MAIN_VALUE; break; } } } //创建马路现状 private function createRoad():void{ for(var i:int = 0; i < GV.WIDTH_NUMBER * GV.HEIGHT_NUMBER; i ++){ var state:State = new State; var ix:int = i % GV.WIDTH_NUMBER; var iy:int = Math.floor(i / GV.HEIGHT_NUMBER); state.value = c[ix][iy]; switch(state.value){ case GV.HAVE_THING://如果等于1表示有障碍 var thing:Thing = new Thing; thing.x = ix * GV.GRID_WIDTH; thing.y = iy * GV.GRID_HEIGHT; things.addChild(thing); thing = null; break; case GV.IMPASSE_VALUE://如多等于2表示死路 //死路只需将value设置成2即可！ break; case GV.MAIN_VALUE://如果等于8表示操控人 main.x = ix * GV.GRID_WIDTH; main.y = iy * GV.GRID_HEIGHT; break; } c[ix][iy] = state; } } //点击触发 private function clickHandle(e:MouseEvent):void{ drawPath.graphics.clear(); targetIX = Math.floor(e.localX / GV.GRID_WIDTH); targetIY = Math.floor(e.localY / GV.GRID_HEIGHT); //时间记录 startTime = getTimer(); var path:Array = seekRoad(); endTime = getTimer(); //根据路径开始走路 walkRoad(path); path = null; } //开始走路 private function walkRoad(path:Array):void{ //显示寻路消耗时间 result.text = GV.RESULT_FRONT + (endTime - startTime) + GV.RESULT_BACK; //判断是否为死路 if(path.length == 0){ result.text = GV.IMPASSE + result.text; } drawPath.graphics.lineStyle(2,0xffffff); path.just = true; intervalID = setInterval(walkRoadHandle,50,path); } //走路处理 private function walkRoadHandle(path:Array):void{ //是否路已经走完 if(path.length == 0){ //结束走路 clearInterval(intervalID); //开启触发器 click.mouseEnabled = true; return; } //开始走路 var obj:Object = path.shift(); main.x = obj.x; main.y = obj.y; obj = null; //绘制路径 if(path.just){ path.just = false; drawPath.graphics.moveTo(main.x + 5,main.y + 5); }else{ drawPath.graphics.lineTo(main.x + 5,main.y + 5); } } //开始寻路 private function seekRoad():Array{ //关闭触发器 click.mouseEnabled = false; //判断目标点是不是有障碍，或者是不是死路 if(c[targetIX][targetIY].isThing || c[targetIX][targetIY].isWalk){ return new Array; } //寻路初始化 var path:Array = new Array; unlockList = new Array; lockList = new Object; //初始标记 var ix:int = main.ix; var iy:int = main.iy; //创建开始标记 var sign:Sign = new Sign(ix,iy,0,0,null); lockList[ix + "_" + iy] = sign; while(true){ //生成八个方向的标记开启 addUnlockList(createSign(ix + 1,iy - 1,true ,sign)); addUnlockList(createSign(ix + 1,iy ,false,sign)); addUnlockList(createSign(ix + 1,iy + 1,true ,sign)); addUnlockList(createSign(ix - 1,iy + 1,true ,sign)); addUnlockList(createSign(ix ,iy + 1,false,sign)); addUnlockList(createSign(ix - 1,iy ,false,sign)); addUnlockList(createSign(ix - 1,iy - 1,true ,sign)); addUnlockList(createSign(ix ,iy - 1,false,sign)); //判断开启列表是否已经为空 if(unlockList.length == 0){ break; } //从开启列表中取出h值最低的标记 unlockList.sortOn("f",Array.NUMERIC); sign = unlockList.shift(); lockList[sign.ix + "_" + sign.iy] = sign; ix = sign.ix; iy = sign.iy; //判断是否找出路径 if(ix == targetIX && iy == targetIY){ while(sign != null){ path.push(sign.getSign()); sign = sign.p; } break; } } sign = null; return path.reverse(); } //添加到开启标记列表 private function addUnlockList(sign:Sign):void{ if(sign){ unlockList.push(sign); unlockList[sign.ix + "_" + sign.iy] = sign; } } //生成标记 private function createSign(ix:int,iy:int,p:Boolean,_p:Sign):Sign{ //是否出格 if(ix < 0 || iy < 0 || ix >= GV.WIDTH_NUMBER || iy >= GV.HEIGHT_NUMBER){ return null; } //是否有障碍物 if(c[ix][iy].isThing){ return null; } //是否已经加入关闭标记列表 if(lockList[ix + "_" + iy]){ return null; } //是否已经加入开启标记列表 if(unlockList[ix + "_" + iy]){ return null; } //判断当斜着走的时候，它的上下或者左右是否有障碍物 if(p){ if(c[_p.ix][iy].isThing || c[ix][_p.iy].isThing){ return null; } } var cx:Number = Math.abs(targetIX - ix); var cy:Number = Math.abs(targetIY - iy); return new Sign(ix,iy, p ? GV.BIAS_VALUE : GV.LINE_VALUE, (cx + cy) * 10, _p); } } }
标记数据记录，Sign.as类
package code{ public class Sign{ private var _ix:Number; private var _iy:Number; private var _p:Sign; private var _f:int = 0; private var _g:int = 0; private var _h:int = 0; //f表示路径评分、g表示当前移动耗费、h表示当前估计移动耗费 //公式：f = g + h，表示路径评分的算法 //ng值表示以父标记为主标记的g值 //nh值表示当前估计移动耗费 public function Sign(_ix:Number,_iy:Number,ng:int,nh:int,_p:Sign = null){ this._ix = _ix; this._iy = _iy; this._p = _p; if(_p){ _g = _p.g + ng; _h = nh; _f = _g + _h; } } //获取该标记的坐标 public function getSign():Object{ return {x:_ix * GV.GRID_WIDTH,y:_iy * GV.GRID_HEIGHT}; } //获取它表示的x坐标 public function get ix():int{ return _ix; } //获取它表示的y坐标 public function get iy():int{ return _iy; } //获取父标记 public function get p():Sign{ return _p; } //获取路径评分 public function get f():int{ return _f; } //获取当前路径移动耗费 public function get g():int{ return _g; } //获取当前路径耗费估值 public function get h():int{ return _h; } //重写toString值 public function toString():String{ return ix + "," + iy; } } }
某点状态类，State.as
package code{ public class State{ public var value:int = 0; public function State(){ } //获取是否障碍 public function get isThing():Boolean{ return value == GV.HAVE_THING; } //获取是否死路 public function get isWalk():Boolean{ return value == GV.IMPASSE_VALUE; } //重写toString public function toString():String{ return value.toString(); } } }
物体类：Thing.as
package code{ import flash.display.Sprite; public class Thing extends Sprite{ public function Thing(){ init(); } //初始化 private function init():void{ graphics.beginFill(0); graphics.drawRect(0,0,GV.GRID_WIDTH,GV.GRID_HEIGHT); mouseEnabled = false; mouseChildren = false; } } }
坐标系类，Coordinate.as
package code{ public dynamic class Coordinate extends Array{ public function Coordinate(){ init(); } //初始化 private function init():void{ for(var i:int = 0; i < GV.WIDTH_NUMBER; i ++){ push(new Array(GV.HEIGHT_NUMBER)); } } } }
主角类，Main.as
package code{ import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ init(); } //初始化 private function init():void{ graphics.beginFill(0x0000ff); graphics.drawRect(0,0,GV.GRID_WIDTH,GV.GRID_HEIGHT); mouseEnabled = false; mouseChildren = false; } //获取ix坐标 public function get ix():int{ return int(x / GV.GRID_WIDTH); } //获取iy坐标 public function get iy():int{ return int(y / GV.GRID_HEIGHT); } } }
代码就告一段落。可以新建fla文件进行测试下的。