前提:我正在构建一个裁剪工具,可以处理图像的双指任意旋转以及任意裁剪。
有时图像最终会以插入空白空间的方式旋转,以填充旋转图像和裁剪矩形之间的间隙(请参见下面的示例)。
我需要确保 ImageView 在旋转时完全适合裁剪矩形。如果没有,我需要重新转换图像(缩放)以使其适合裁剪范围。
使用 this answer ,我已经实现了检查旋转的 UIImageView 是否与裁剪 CGRect 相交的功能,但不幸的是,这并没有告诉我裁剪矩形是否完全包含在旋转的 ImageView 中。希望我可以对这个答案做一些简单的修改?
OK 的视觉示例:
但不是 OK,我需要检测和处理的是:
更新:无效方法
- (BOOL)rotatedView:(UIView*)rotatedView containsViewCompletely:(UIView*)containedView {
CGRect rotatedBounds = rotatedView.bounds;
CGPoint polyContainedView[4];
polyContainedView[0] = [containedView convertPoint:rotatedBounds.origin toView:rotatedView];
polyContainedView[1] = [containedView convertPoint:CGPointMake(rotatedBounds.origin.x + rotatedBounds.size.width, rotatedBounds.origin.y) toView:rotatedView];
polyContainedView[2] = [containedView convertPoint:CGPointMake(rotatedBounds.origin.x + rotatedBounds.size.width, rotatedBounds.origin.y + rotatedBounds.size.height) toView:rotatedView];
polyContainedView[3] = [containedView convertPoint:CGPointMake(rotatedBounds.origin.x, rotatedBounds.origin.y + rotatedBounds.size.height) toView:rotatedView];
if (CGRectContainsPoint(rotatedView.bounds, polyContainedView[0]) &&
CGRectContainsPoint(rotatedView.bounds, polyContainedView[1]) &&
CGRectContainsPoint(rotatedView.bounds, polyContainedView[2]) &&
CGRectContainsPoint(rotatedView.bounds, polyContainedView[3]))
return YES;
else
return NO;
}
最佳答案
这应该比检查交集(如在引用的线程中)更容易。
(旋转的) ImageView 是一个凸四边形。因此检查就足够了 裁剪矩形的所有 4 个角点都在旋转的 ImageView 内。
- 使用
[cropView convertPoint:point toView:imageView]
将裁剪矩形的角点转换为坐标系 (旋转) ImageView 。 - 使用
CGRectContainsPoint()
检查 4 个转换角点是否在 ImageView 的bounds
矩形内。
示例代码:
- (BOOL)rotatedView:(UIView *)rotatedView containsCompletely:(UIView *)cropView {
CGPoint cropRotated[4];
CGRect rotatedBounds = rotatedView.bounds;
CGRect cropBounds = cropView.bounds;
// Convert corner points of cropView to the coordinate system of rotatedView:
cropRotated[0] = [cropView convertPoint:cropBounds.origin toView:rotatedView];
cropRotated[1] = [cropView convertPoint:CGPointMake(cropBounds.origin.x + cropBounds.size.width, cropBounds.origin.y) toView:rotatedView];
cropRotated[2] = [cropView convertPoint:CGPointMake(cropBounds.origin.x + cropBounds.size.width, cropBounds.origin.y + cropBounds.size.height) toView:rotatedView];
cropRotated[3] = [cropView convertPoint:CGPointMake(cropBounds.origin.x, cropBounds.origin.y + cropBounds.size.height) toView:rotatedView];
// Check if all converted points are within the bounds of rotatedView:
return (CGRectContainsPoint(rotatedBounds, cropRotated[0]) &&
CGRectContainsPoint(rotatedBounds, cropRotated[1]) &&
CGRectContainsPoint(rotatedBounds, cropRotated[2]) &&
CGRectContainsPoint(rotatedBounds, cropRotated[3]));
}
关于ios - 确定 crop rect 是否完全包含在旋转的 UIView 中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/26821725/