OBB碰撞检测，坐标点逆时针
class OBBTest extends egret.DisplayObjectContainer {
private obb1:OBB;
private obb2:OBB;
private points1:Array<egret.Point>;
private points2:Array<egret.Point>;
private sprite1:egret.Sprite;
private sprite2:egret.Sprite;
private resPoint:egret.Point = new egret.Point();
constructor() {
super();
this.touchEnabled = true;
var stage = egret.MainContext.instance.stage;
stage.addEventListener(egret.TouchEvent.TOUCH_BEGIN, this.onTouchBegin, this);
stage.addEventListener(egret.TouchEvent.TOUCH_MOVE, this.onTouchMove, this);
stage.addEventListener(egret.TouchEvent.TOUCH_END, this.onTouchEnd, this);
this.points1 = [new egret.Point(0,0),new egret.Point(100,200),new egret.Point(300,300),new egret.Point(300,100),new egret.Point(0,0)];
this.sprite1 = this.drawSprite(this.points1);
this.addChild(this.sprite1);
this.sprite1.x = 100;
this.sprite1.y = 100;
this.points2 = [new egret.Point(0,0),new egret.Point(100,200),new egret.Point(300,300),new egret.Point(300,100),new egret.Point(0,0)];
this.sprite2 = this.drawSprite(this.points2);
this.addChild(this.sprite2);
this.sprite2.x = 100;
this.sprite2.y = 400;
//创建两obb盒子
this.obb1 = new OBB();
this.obb2 = new OBB();
egret.startTick(this.onEnterFrame, this);
}
private pt:egret.Point = new egret.Point(0,0);
private onEnterFrame():boolean {
for (var i = 0; i < this.points1.length; i++) {
var point1:egret.Point = this.points1[i];
this.sprite1.localToGlobal(point1.x, point1.y, this.pt);
this.obb1.setVertex(i, this.pt.x, this.pt.y);
}
for (var j = 0; j < this.points2.length; j++) {
var point2:egret.Point = this.points2[j];
this.sprite2.localToGlobal(point2.x, point2.y, this.pt);
this.obb2.setVertex(j, this.pt.x, this.pt.y);
}
this.sprite1.visible = !this.obb1.isCollidWithOBB(this.obb2);
return false;
}
private drawSprite(points:Array<egret.Point>):egret.Sprite {
var startPoint:egret.Point = points[0];
var sprite = new egret.Sprite();
sprite.graphics.clear();
sprite.graphics.beginFill( 0xffffff, 0.5 );
sprite.graphics.moveTo( startPoint.x, startPoint.y );
for (var i = 1; i < points.length ; i++) {
var point = points[i];
sprite.graphics.lineTo( point.x, point.y );
}
sprite.graphics.endFill();
return sprite;
}
private onTouchBegin(evt:egret.TouchEvent):void {
var posX = evt.stageX;
var posY = evt.stageY;
this.sprite2.x = posX;
this.sprite2.y = posY;
}
private onTouchMove(evt:egret.TouchEvent):void {
var posX = evt.stageX;
var posY = evt.stageY;
this.sprite2.x = posX;
this.sprite2.y = posY;
}
private onTouchEnd(evt:egret.TouchEvent):void {
var posX = evt.stageX;
var posY = evt.stageY;
this.sprite2.x = posX;
this.sprite2.y = posY;
}
}/**
* 投影判断
*/
class Projection {
private min:number = 0;
private max:number = 0;
constructor(min, max) {
this.min = min;
this.max = max;
} public getMin(){
return this.min;
} public getMax(){
return this.max;
} /**
* 判断是否叠加
*/
public overlap(proj:Projection):boolean {
if(this.min > proj.getMax()) return false;
if(this.max < proj.getMin()) return false; return true;
}
};
class OBB {
private pList:Array<any> = [] //保存盒子顶点数
constructor() {
this.pList = [];
}
public getVertex(idx):egret.Point {
if (idx >= this.pList.length) {
return null;
}
return this.pList[idx];
};
public setVertex(idx:number, x:number, y:number):void {
if (!this.pList[idx]) {
this.pList[idx] = new egret.Point(0, 0);
}
this.pList[idx].x = x;
this.pList[idx].y = y;
}
/**
* 计算分离轴
* 如果边向量为(x,y)，那么法向量为(-y,x)，你也可以设置为(y,-x)。结果没有什么变化。
*/
public getAxies():Array<egret.Point> {
var axies = [];
var len = this.pList.length;
var pOut = new egret.Point(0,0);
for(var i = 0; i < len; i++) {
var startPoint:egret.Point = this.pList[i];
var endPoint:egret.Point = this.pList[(i + 1) % len];
var point = startPoint.subtract(endPoint);
var length = Math.sqrt(point.x * point.x + point.y * point.y);
pOut.x = point.x / length;
pOut.y = point.y / length;
axies[i] = new egret.Point();
axies[i].x = -pOut.y ;
axies[i].y = pOut.x ;
}
return axies;
}
/**
* 计算投影
* 计算出一个投影线条
* 只是保存了两个float形的数据，分别表示OBB盒在分离轴上投影的最小值和最大值
*/
public getProjection(axies:egret.Point):Projection {
var min = this.pList[0].x * axies.x + this.pList[0].y * axies.y;
var max = min ;
var len = this.pList.length;
for (var i = 1; i < len; i++) {
var temp = this.pList[i].x * axies.x + this.pList[i].y * axies.y;
if (temp > max) {
max = temp;
} else if (temp < min) {
min = temp;
}
}// end for
return new Projection(min, max);
}
//对传递进来的OBB判断是否与调用这个方法的OBB发生了交叉
public isCollidWithOBB(obb:OBB):boolean {
//获取分离轴
var axies1 = this.getAxies();
var axies2 = obb.getAxies();
var p1:Projection = null;
var p2:Projection = null;
//Check for overlap for all of the axies
for(var i = 0; i < axies1.length; i++)
{
p1 = this.getProjection(axies1[i]);
p2 = obb.getProjection(axies1[i]);
if(!p1.overlap(p2))
{
return false ;
}
}
for(var j = 0; j < axies2.length; j ++)
{
p1 = this.getProjection(axies2[j]);
p2 = obb.getProjection(axies2[j]);
if(!p1.overlap(p2))
{
return false ;
}
}
return true ;
}
}测试,在Main中添加
var obb = new OBBTest();
this.addChild(obb);