JSJP_School/LN_School/PureCamera/UIImage+CropRotate.m

//
//  UIImage+CropRotate.m
//
//  Copyright 2015 Timothy Oliver. All rights reserved.
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to
//  deal in the Software without restriction, including without limitation the
//  rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
//  sell copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
//  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
//  IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

#import "UIImage+CropRotate.h"

@implementation UIImage (CropRotate)

- (UIImage *)croppedImageWithFrame:(CGRect)frame angle:(NSInteger)angle
{
    UIImage *croppedImage = nil;
    CGPoint drawPoint = CGPointZero;
    
    UIGraphicsBeginImageContextWithOptions(frame.size, YES, self.scale);
    {
        CGContextRef context = UIGraphicsGetCurrentContext();
        
        //To conserve memory in not needing to completely re-render the image re-rotated,
        //map the image to a view and then use Core Animation to manipulate its rotation
        if (angle != 0) {
            UIImageView *imageView = [[UIImageView alloc] initWithImage:self];
            imageView.layer.minificationFilter = @"nearest";
            imageView.layer.magnificationFilter = @"neareset";
            imageView.transform = CGAffineTransformRotate(CGAffineTransformIdentity, angle * (M_PI/180.0f));
            CGRect rotatedRect = CGRectApplyAffineTransform(imageView.bounds, imageView.transform);
            UIView *containerView = [[UIView alloc] initWithFrame:(CGRect){CGPointZero, rotatedRect.size}];
            [containerView addSubview:imageView];
            imageView.center = containerView.center;
            CGContextTranslateCTM(context, -frame.origin.x, -frame.origin.y);
            [containerView.layer renderInContext:context];
        }
        else {
            CGContextTranslateCTM(context, -frame.origin.x, -frame.origin.y);
            [self drawAtPoint:drawPoint];
        }
        
        croppedImage = UIGraphicsGetImageFromCurrentImageContext();
    }
    UIGraphicsEndImageContext();
    
    return croppedImage;
}


@end