我从“AdvanceED_ActionScript_Animation”电子书中学习了星星寻路:
- 项目清单
- 我制作节点类 Node.as 。
- 我制作网格类 Grid.as 。
- 我做 AStar 类, AStar.as 。
- 和主要类 Game.as 。A-star Pathfinding 是工作,但只有 1 名玩家。如何让它在多人游戏中工作?
剧透 4.Game.as :
package
{
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.events.Event;
import flash.events.MouseEvent;
public class Game extends Sprite
{
private var _cellSize:int = 30;
private var _grid:Grid;
private var _player:Sprite;
private var _index:int;
private var _path:Array;
public function Game()
{
stage.align = StageAlign.TOP_LEFT;
stage.scaleMode = StageScaleMode.NO_SCALE;
makePlayer();
makeGrid();
stage.addEventListener(MouseEvent.CLICK, onGridClick);
}
private function makePlayer():void
{
_player =new Sprite();
_player.graphics.beginFill(0x336633);
_player.graphics.drawCircle(0,0,5);
_player.graphics.endFill();
_player.x = Math.random() * 100;
_player.y = Math.random() * 100;
addChild(_player);
}
private function makeGrid():void
{
_grid = new Grid(10,10);
for (var i:int =0; i < 10; i++)
{
_grid.setWalkable(Math.floor(Math.random()*10),
Math.floor(Math.random()*10),false);
}
drawGrid();
}
private function drawGrid():void
{
graphics.clear();
for (var i:int =0; i < _grid.numCols; i++)
{
for (var j:int =0; j<_grid.numRows; j++)
{
var node:Node = _grid.getNode(i,j);
graphics.lineStyle(0);
graphics.beginFill(getColor(node));
graphics.drawRect(i *_cellSize,
j*_cellSize,_cellSize,
_cellSize);
}
}
}
private function getColor(node:Node):uint
{
if (! node.walkable)
{
return 0;
}
if (node == _grid.startNode)
{
return 0xcccccc;
}
if (node == _grid.endNode)
{
return 0xcccccc;
}
return 0xffffff;
}
private function onGridClick(event:MouseEvent):void
{
var xpos:int =Math.floor(mouseX/_cellSize);
var ypos:int =Math.floor(mouseY/_cellSize);
_grid.setEndNode(xpos,ypos);
xpos = Math.floor(_player.x / _cellSize);
ypos = Math.floor(_player.y / _cellSize);
_grid.setStartNode(xpos,ypos);
drawGrid();
findPath();
}
private function findPath():void
{
var astar:AStar = new AStar();
if (astar.findPath(_grid))
{
_path = astar.path;
_index = 0;
addEventListener(Event.ENTER_FRAME, onEnterFrame);
}
}
private function onEnterFrame(event:Event):void
{
var targetX:Number = _path[_index].x * _cellSize
+ _cellSize / 2;
var targetY:Number = _path[_index].y * _cellSize
+ _cellSize / 2;
var dx:Number = targetX - _player.x;
var dy:Number = targetY - _player.y;
var dx2:Number = targetX - _box.x;
var dy2:Number = targetY - _box.y;
var dist2:Number =Math.sqrt(dx2*dx2+dy2+dy2);
var dist:Number =Math.sqrt(dx*dx+dy+dy);
if (dist<1)
{
_index++;
if (_index >= _path.length)
{
removeEventListener(Event.ENTER_FRAME,onEnterFrame);
}
}
else
{
_player.x += dx * .5;
_player.y += dy * .5;
}
}
}
}