SKAction:如何动画随机重复动作

Question

我想SKAction在每次重复时运行重复但随机的值.我在这里读到了这个问题,显示了一种方法.但是,我希望我的精灵动作能够动画,而不是简单地改变它的位置.我提出的一个解决方案是运行一系列操作,最后一个动作以递归方式调用我的move方法:

- (void)moveTheBomber {
    __weak typeof(self) weakSelf = self;

    float randomX = //  determine new "randomX" position

    SKAction *moveAction = [SKAction moveToX:randomX duration:0.25f];
    SKAction *waitAction = [SKAction waitForDuration:0.15 withRange:0.4];
    SKAction *completionAction = [SKAction customActionWithDuration:0 actionBlock:^(SKNode *node, CGFloat elapsedTime) {
        [weakSelf moveTheBomber];
    }];

    SKAction *sequence = [SKAction sequence:@[moveAction, waitAction, completionAction]];

    [self.bomber runAction:sequence];
}

递归调用这个方法对我来说感觉'icky',但鉴于我对SpriteKit的经验有限,似乎是最明显的实现方法.

如何在屏幕上永久动画精灵的随机移动？

Answer 1

没有花里胡哨,但我认为这应该会让你顺利:

编辑:对不起它应该是:

SKAction *randomXMovement = [SKAction runBlock:^(void){
    NSInteger xMovement = arc4random() % 20;
    NSInteger leftOrRight = arc4random() % 2;
    if (leftOrRight == 1) {
        xMovement *= -1;
    }
    SKAction *moveX = [SKAction moveByX:xMovement y:0 duration:1.0];
    [aSprite runAction:moveX];
}];

SKAction *wait = [SKAction waitForDuration:1.0];
SKAction *sequence = [SKAction sequence:@[randomXMovement, wait]];
SKAction *repeat = [SKAction repeatActionForever:sequence];
[aSprite runAction: repeat];