android圆周运动动画,教你如何实现Cocos2D-Android中图片围绕点做圆周运动

相信各位同学偶尔会看到有些手机游戏中会出项一张图片围着某个点作圆周运动，本篇教程将教你如何实现Cocos2D-Android中图片围绕点做圆周运动 。

实现效果：

具体代码：

publicclassCCRoundByextendsCCIntervalAction{

booleanturn;//ForwardorReverseround

floatstartAngle;//default

floatradius;//Roundcircleradius

CGPointcenter;//Roundcirclecenterpoint

publicbooleanisTurn(){

returnturn;

}

publicvoidsetTurn(booleanturn){

this.turn=turn;

}

publicfloatgetStartAngle(){

returnstartAngle;

}

publicvoidsetStartAngle(floatstartAngle){

this.startAngle=startAngle;

}

publicfloatgetRadius(){

returnradius;

}

publicvoidsetRadius(floatradius){

this.radius=radius;

}

publicCGPointgetCenter(){

returncenter;

}

publicvoidsetCenter(CGPointcenter){

this.center=center;

}

/**createstheaction*/

publicstaticCCRoundByaction(floatduration,booleana,CGPointpoint,floatr){

returnnewCCRoundBy(duration,a,point,r);

}

/**initializestheaction*/

protectedCCRoundBy(floatduration,booleana,CGPointpoint,floatr){

super(duration);

turn=a;

radius=r;

center=point;

}

@Override

publicvoidstart(CCNodeaTarget){

super.start(aTarget);

startAngle=aTarget.getRotation();

if(turn){

((CCNode)aTarget).setPosition(CGPoint.ccpAdd(center,CGPoint.ccp(-radius,0)));

}

else{

((CCNode)aTarget).setPosition(CGPoint.ccpAdd(center,CGPoint.ccp(radius,0)));

}

}

@Override

publicvoidupdate(floatt){

//XXX:shallIadd%360

floatrotate=(startAngle+360.0f*t);

if(turn){

rotate*=-1;

}

target.setRotation(rotate);

floatfradian=(float)(rotate*Math.PI/180.0f);

CGPointpos=CGPoint.ccp(center.x+radius*MathUtils.sin(fradian),

center.y+radius*MathUtils.cos(fradian));

target.setPosition(pos);

}

@Override

publicCCIntervalActionreverse(){

booleanresult=!turn;

returnaction(duration,result,center,radius);

}

}