Question

我遇到一个真正的麻烦，让精灵在顶部的屏幕上产生，然后从顶部到底部动画。我一直在关注Ray Wenderlich关于创建一个简单游戏的教程，然而将精灵从右向左移动，我希望它从上到下移动，现在我非常困难！以下是我目前的代码：

- (void)addComet:(CCTime)dt
{
    // Make sprite
    CCSprite *comet = [CCSprite spriteWithImageNamed:@"PlayerSprite.png"];

    // Verticle spawn range
    int minY = comet.contentSize.width;
    int maxY = self.contentSize.height - comet.contentSize.height / 2;
    int rangeY = maxY - minY;
    int randomY = (arc4random() % rangeY) + minY;

    // Position comets slightly off the screen
    comet.position = CGPointMake(self.contentSize.width + comet.contentSize.width, randomY);
    [self addChild:comet];

    // Duration range comets take to fly across screen
    int minDuration = 2.0;
    int maxDuration = 4.0;
    int rangeDuration = maxDuration - minDuration;
    int randomDuration = (arc4random() % rangeDuration) + minDuration;

    // Give comet animation
    CCAction *actionMove = [CCActionMoveTo actionWithDuration:randomDuration position:CGPointMake(0, 500)];
    CCAction *actionRemove = [CCActionRemove action];
    [comet runAction:[CCActionSequence actionWithArray:@[actionMove,actionRemove]]];
}

如果有人能指出我正确的方向，因为我已经坚持了很长一段时间，并且无法让精灵在屏幕顶部随机生成，然后动画到底部。我也看过像tweejump这样的示例代码，但没有运气。

Answer 1

现在，我的任何项目中都没有Cocos2D，所以不知道是否有任何拼写错误，但通常它应该看起来像下面的东西。这个想法是所有的彗星都应该从相同的 Y位置（屏幕外）开始，但是有一个随机的水平（x）位置......

- (void)addComet:(CCTime)dt
{
    // Make sprite
    CCSprite *comet = [CCSprite spriteWithImageNamed:@"PlayerSprite.png"];

    NSInteger y = self.contentSize.height; // perhaps + comet.contentSize.height / 2, if the anchorPoint is 0.5, 0.5

    // Random horizontal position
    NSInteger maxX = self.contentSize.width;
    NSInteger randomX = (arc4random() % maxX);

    // Position comets slightly off the screen
    comet.position = CGPointMake(randomX, y);
    [self addChild:comet];

    // Duration range comets take to fly across screen
    NSInteger minDuration = 2.0;
    NSInteger maxDuration = 4.0;
    NSInteger rangeDuration = maxDuration - minDuration;
    NSInteger randomDuration = (arc4random() % rangeDuration) + minDuration;

    // Give comet animation
    CCAction *actionMove = [CCActionMoveTo actionWithDuration:randomDuration position:CGPointMake(randomX, 0)]; // Moving it in a straight line vertically
    CCAction *actionRemove = [CCActionRemove action];
    [comet runAction:[CCActionSequence actionWithArray:@[actionMove,actionRemove]]];
}

垂直动画精灵

1 个答案: