6

我已经创建了自己的解决方案，用于在特定 SKNode 上放大或缩小，而无需缩放整个场景，它似乎主要按照我期望的方式工作，有两个值得注意的例外，我希望在这里得到输入. 首先是代码（这个控制语句在 touchesMoved 方法中）：

 if (touches.count == 2) {
        // this means there are two fingers on the screen
        NSArray *fingers = [touches allObjects];
        CGPoint fingOneCurr = [fingers[0] locationInNode:self];
        CGPoint fingOnePrev = [fingers[0] previousLocationInNode:self];
        CGPoint fingTwoCurr = [fingers[1] locationInNode:self];
        CGPoint fingTwoPrev = [fingers[1] previousLocationInNode:self];

        BOOL yPinch = fingOneCurr.y > fingOnePrev.y && fingTwoCurr.y < fingTwoPrev.y;
        BOOL yUnpinch = fingOneCurr.y < fingOnePrev.y && fingTwoCurr.y > fingTwoPrev.y;

        BOOL xPinch = fingOneCurr.x > fingOnePrev.x && fingTwoCurr.x < fingTwoPrev.x;
        BOOL xUnpinch = fingOneCurr.x < fingOnePrev.x && fingTwoCurr.x > fingTwoPrev.x;

        if (xUnpinch | yUnpinch) {
            if (YES) NSLog(@"This means an unpinch is happening");
            mapScale = mapScale +.02;
            [map setScale:mapScale];
        }

        if (xPinch | yPinch) {
            if (YES) NSLog(@"This means a pinch is happening");
            mapScale = mapScale - .02;
            [map setScale:mapScale];
        }
    }

现在的问题：

  1. 捏和松开有时并不总是正确的，当这种情况发生时我不能完全把手指放在上面，捏会表现为松开，反之亦然。

  2. 当捏合和松开正确缩放 SKNode 时，它​​很少像我想要的那样平滑。我觉得有点烦人。

任何人都可以建议改进这种方法吗？谢谢！

4

1 回答 1

8

这将解决您的问题，感谢 Steffen 的提示。

- (void)didMoveToView:(SKView *)view
{
    UIPinchGestureRecognizer *precog = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)];
    [self.scene.view addGestureRecognizer:precog];
}

- (void)handlePinch:(UIPinchGestureRecognizer *) recognizer
{
    //NSLog(@"Pinch %f", recognizer.scale);
    //[_bg setScale:recognizer.scale];
    [_bg runAction:[SKAction scaleBy:recognizer.scale duration:0]];
    recognizer.scale = 1;
}
于 2013-10-19T12:16:12.300 回答