我正在尝试绘制一个跟随屏幕触摸的标尺。在第一次触摸时,我设置了第一个点,在所有其他点上,标尺跟随屏幕上的手指调整大小并根据手指的位置围绕第一个点旋转。
我试图这样做:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint p = [touch locationInView:self.view];
self.regleFirstPoint = p;
UIImageView* img = [[UIImageView alloc] initWithImage:self.regleImg];
img.frame = CGRectMake(self.regleFirstPoint.x, self.regleFirstPoint.y, 0, self.regleImg.size.height);
[self.view addSubview:img];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint p = [touch locationInView:self.view];
// Width
float deltaY = p.y - self.regleFirstPoint.y;
float deltaX = p.x - self.regleFirstPoint.x;
float width = sqrt((deltaX * deltaX) + (deltaY * deltaY));
// Angle
float angleInRadians = atanf(deltaY / deltaX);
float angleInDegrees = angleInRadians * 180 / M_PI; // JUST FOR INFO
NSLog(@"angle : %f / %f", angleInRadians, angleInDegrees);
// Resizing image
UIImageView* img = [self.regles lastObject];
img.frame = CGRectMake(self.regleFirstPoint.x, self.regleFirstPoint.y, width, self.regleImg.size.height/2);
img.center = self.regleFirstPoint;
CGAffineTransform transform = CGAffineTransformIdentity;
img.transform = CGAffineTransformRotate(transform, angleInRadians);
}
标尺没有正确跟随手指,我想我错过了一些东西。我的代码有什么问题?
编辑:经过一些研究,我也尝试了这个:
// Resizing images
img.frame = CGRectMake(self.regleFirstPoint.x, self.regleFirstPoint.y, largeur, self.regleImg.size.height/2);
[img.layer setAnchorPoint:CGPointMake(self.regleFirstPoint.x / img.bounds.size.width, self.regleFirstPoint.y / img.bounds.size.height)];
img.transform = CGAffineTransformRotate(img.transform, angleInRadians);