Question

每次触摸屏幕时都会出现精灵，然后拍摄到所需的区域。我怎么能让它一次只有一个精灵在现场，直到它退出现场或击中一个物体？（即使多次触摸屏幕）

这是射弹代码

- (void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
// 1
CGPoint touchLocation = [touch locationInNode:self];

// 2
CGPoint offset    = ccpSub(touchLocation, _player.position);
float   ratio     = offset.y/offset.x;
int     targetX   = _player.contentSize.width/2 + self.contentSize.width;
int     targetY   = (targetX*ratio) + _player.position.y;
CGPoint targetPosition = ccp(targetX,targetY);

// 3
CCSprite *projectile = [CCSprite spriteWithImageNamed:@"projectile.png"];
projectile.position = _player.position;
projectile.physicsBody = [CCPhysicsBody bodyWithCircleOfRadius:projectile.contentSize.width/2.0f andCenter:projectile.anchorPointInPoints];
projectile.physicsBody.collisionGroup = @"playerGroup";
projectile.physicsBody.collisionType  = @"projectileCollision";
[_physicsWorld addChild:projectile];

// 4
CCActionMoveTo *actionMove   = [CCActionMoveTo actionWithDuration:1.5f position:targetPosition];
CCActionRemove *actionRemove = [CCActionRemove action];
[projectile runAction:[CCActionSequence actionWithArray:@[actionMove,actionRemove]]];

[[OALSimpleAudio sharedInstance] playEffect:@"pew-pew-lei.caf"];

}

Answer 1

如果我理解你的观点，你可以简单地添加一个标志，以便能够注意到场景中已有精灵。只需在你的班级上宣布一个

BOOL isSpritePresent;

在您的类自定义ID方法上初始化它。

-(id)init {
self=[super init];
isSpritePresent=NO;
return self; }

然后在TouchBegan的开头添加类似

的内容

if(isSpritePresent){
return; //As there's already an sprite on the scene.
}

最后

isSpritePresent=YES;

最后当箭头或w / e到达目标时，调用方法重置布尔值。

或者......如果你期待事情变得更简单，并且你相信你有一个特定的时间让用户再次拍摄，那么只需在其他行动之后加上延迟......

CCActionDelay *delay = [CCActionDelay actionWithDuration:1.2f];
        [projectile runAction:[CCActionSequence actionWithArray:@[actionMove,actionRemove,delay]]];

一次只有一个精灵在Cocos2D 3.x上

1 个答案: