Question

我有一个似乎无法解决的问题。我想基于手指移动在屏幕上移动一个精灵，但不是让精灵向移动触摸位置，我希望精灵以相同的方式移动手指在屏幕上移动。

实施例：用户将他/她的手指放在屏幕上（任何位置），然后将屏幕上的手指向左拖动200像素，精灵也应向左移动200像素。

我的方法是在开始时存储玩家的位置，然后计算手指的起始位置和当前位置之间的差异，以添加到精灵本身的起始位置。

这是我的代码

-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
if([touches count] == 1){
    UITouch *touch = [touches anyObject];
    CGPoint startPos = [touch locationInView:[touch view]];
    startPosition = startPos;
}

}

-(void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    if([touches count] == 1){
        UITouch *touch = [touches anyObject];
        CGPoint touchPos = [touch locationInView:[touch view]];
        CGPoint playerPos = player.position;

        float yDifference = startPosition.y - touchPos.y;
        playerPos.y = playerPos.y - yDifference;

        // just to change to GL coordinates instead of the ones used by Cocos2D
        // still doesn't work even if I remove this...
        CGPoint convertedPoint = [[CCDirector sharedDirector] convertToGL:playerPos];
        [player setPosition:convertedPoint];
    }

}

我希望我的问题很清楚，但如果不是，请不要犹豫，提出问题或进一步解释。我已经坚持了很长一段时间：'（

Answer 1

此外，如果您希望它将“相对”移动到它开始的位置，而不是确切地移动到的位置：

-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    if([touches count] == 1){
      UITouch *touch = [touches anyObject];
      CGPoint startPos = [touch locationInView:[touch view]];
      startPosition = startPos;
      playerStartPos = playerPos;
    }
 }

-(void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    if([touches count] == 1){
      UITouch *touch = [touches anyObject];
      CGPoint touchPos = [touch locationInView:[touch view]];

      CGPoint newPlayerPos;
      newPlayerPos.x = playerStartPos.x + (touchPos.x - startPosition.x);
      newPlayerPos.y = playerStartPos.y + (touchPos.y - startPosition.y);

      // just to change to GL coordinates instead of the ones used by Cocos2D
      // still doesn't work even if I remove this...
      CGPoint convertedPoint = [[CCDirector sharedDirector] convertToGL:newPlayerPos];
      [player setPosition:convertedPoint];
}

你的代码看起来像是通过不断向playerPos.y

添加差异而“反馈”到自己身上。

Answer 2

所以只是不要使用差异，使用当前的触摸位置：

-(void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
    if([touches count] == 1){
        UITouch *touch = [touches anyObject];
        CGPoint playerPos = [touch locationInView:[touch view]];

        // just to change to GL coordinates instead of the ones used by Cocos2D
        // still doesn't work even if I remove this...
        CGPoint convertedPoint = [[CCDirector sharedDirector] convertToGL:playerPos];
        [player setPosition:convertedPoint];
    }

Cocos2D雪碧相对运动

2 个答案: