我正在通过触摸裁剪图像。为此，我正在使用UIBezierPath.
我可以裁剪出选定的区域，但不需要的区域（不在裁剪部分内）仍然没有占用空间。或者换句话说，我无法摆脱裁剪区域之外的区域。
那么，我怎样才能删除这个不需要/无用的区域？
这是我的代码：
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UIView *touchedView = [delegate viewForUseWithTool:self];
for (UITouch *touch in [event allTouches]) {
// remember the touch, and its original start point, for future
[trackingTouches addObject:touch];
CGPoint location = [touch locationInView:touchedView];
[startPoints addObject:[NSValue valueWithCGPoint:location]];
UIBezierPath *path = [UIBezierPath bezierPath];
path.lineCapStyle = kCGLineCapRound;
[path moveToPoint:location];
[path setLineWidth:delegate.strokeWidth];
[path addLineToPoint:location];
[paths addObject:path];
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
for (UITouch *touch in [event allTouches]) {
// make a line from the start point to the current point
NSUInteger touchIndex = [trackingTouches indexOfObject:touch];
// only if we actually remember the start of this touch...
if (touchIndex != NSNotFound) {
UIBezierPath *path = [paths objectAtIndex:touchIndex];
PathDrawingInfo *info = [PathDrawingInfo pathDrawingInfoWithPath:path fillColor:[UIColor clearColor] strokeColor:delegate.strokeColor];
[delegate addDrawable:info];
[trackingTouches removeObjectAtIndex:touchIndex];
[startPoints removeObjectAtIndex:touchIndex];
[paths removeObjectAtIndex:touchIndex];
}
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
for (UITouch *touch in [event allTouches]) {
// make a line from the start point to the current point
NSUInteger touchIndex = [trackingTouches indexOfObject:touch];
// only if we actually remember the start of this touch...
if (touchIndex != NSNotFound) {
UIBezierPath *path = [paths objectAtIndex:touchIndex];
PathDrawingInfo *info = [PathDrawingInfo pathDrawingInfoWithPath:path fillColor:[UIColor clearColor] strokeColor:delegate.strokeColor];
[delegate addDrawable:info];
[trackingTouches removeObjectAtIndex:touchIndex];
[startPoints removeObjectAtIndex:touchIndex];
[paths removeObjectAtIndex:touchIndex];
}
}
}