我正在开发一款带有某些游戏场的游戏,该游戏场是在某些 View 中绘制的。我的游戏领域总是相对于他的中心绘制,所以我只是简单地捏一下
- (void)pinch:(UIPinchGestureRecognizer *)gesture
{
if ((gesture.state == UIGestureRecognizerStateChanged) ||
(gesture.state == UIGestureRecognizerStateEnded)) {
self.gameBoardGridView.scale *= gesture.scale; // adjust our scale
gesture.scale = 1;
}
平移
-(void)pan:(UIPanGestureRecognizer *)recognizer
{
CGPoint translatedPoint = [recognizer translationInView:self.gameBoardGridView];
self.gameBoardGridView.gridCenter = CGPointMake(self.gameBoardGridView.gridCenter.x + translatedPoint.x, self.gameBoardGridView.gridCenter.y + translatedPoint.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self.gameBoardGridView];
}
但我需要其他类型的变焦。当您放下两根手指然后移动其中一根时,场会像它应该的那样扩展(放大),但手指下方的像素不再位于手指下方。图像从图像中心开始缩放,而不是两根手指之间的中点。
我尝试了很多例子,但没有一个像我想要的那样工作。最后我写了这个,它几乎可以正常工作,但不完全
- (void)pinch:(UIPinchGestureRecognizer *)gesture
{
CGFloat curScale = gesture.scale;
static CGPoint startPoint;
if (gesture.state == UIGestureRecognizerStateBegan) {
startPoint = [gesture locationInView:self.gameBoardGridView];
}
if ((gesture.state == UIGestureRecognizerStateChanged) ||
(gesture.state == UIGestureRecognizerStateEnded)) {
self.gameBoardGridView.scale *= gesture.scale;
CGFloat widthDelta = self.gameBoardGridView.gridWidth * fabs(gesture.scale - 1) / 3;
CGFloat heightDelta = self.gameBoardGridView.gridHeight * fabs(gesture.scale - 1) / 3;
gesture.scale = 1;
CGPoint lastPoint = self.gameBoardGridView.gridCenter;
const CGFloat epsilon = 5;
CGFloat coef = 1.0;
if(curScale < 1) {
coef = -1.0;
}
if (startPoint.x + epsilon < self.view.frame.size.width / 2) {
lastPoint.x += widthDelta*coef;
}
else if (startPoint.x - epsilon > self.view.frame.size.width / 2) {
lastPoint.x -= widthDelta*coef;
}
if (startPoint.y + epsilon < self.view.frame.size.height / 2) {
lastPoint.y += heightDelta*coef;
}
else if (startPoint.y - epsilon > self.view.frame.size.height / 2) {
lastPoint.y -= heightDelta*coef;
}
self.gameBoardGridView.gridCenter = lastPoint;
}
}
可能还有其他方法可以做到这一点?
最佳答案
缩放的中心是图像的 anchor 。 你要做的就是把 anchor 改成手指的中点,位置,位置。 没有自己尝试购买我在这里看到了一个完整的解决方案,也许它会对你有所帮助 -
关于ios - 我怎样才能像在谷歌地图中那样缩放,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17429614/