YYXC_School/LN_School/PureCamera/LLSimpleCamera+Helper.m

//
//  LLSimpleCamera+Helper.m
//  LLSimpleCameraExample
//
//  Created by Ömer Faruk Gül on 20/02/16.
//  Copyright © 2016 Ömer Faruk Gül. All rights reserved.
//

#import "LLSimpleCamera+Helper.h"

@implementation LLSimpleCamera (Helper)

- (CGPoint)convertToPointOfInterestFromViewCoordinates:(CGPoint)viewCoordinates
                                          previewLayer:(AVCaptureVideoPreviewLayer *)previewLayer
                                                 ports:(NSArray<AVCaptureInputPort *> *)ports
{
    CGPoint pointOfInterest = CGPointMake(.5f, .5f);
    CGSize frameSize = previewLayer.frame.size;
    
    if ( [previewLayer.videoGravity isEqualToString:AVLayerVideoGravityResize] ) {
        pointOfInterest = CGPointMake(viewCoordinates.y / frameSize.height, 1.f - (viewCoordinates.x / frameSize.width));
    } else {
        CGRect cleanAperture;
        for (AVCaptureInputPort *port in ports) {
            if (port.mediaType == AVMediaTypeVideo) {
                cleanAperture = CMVideoFormatDescriptionGetCleanAperture([port formatDescription], YES);
                CGSize apertureSize = cleanAperture.size;
                CGPoint point = viewCoordinates;
                
                CGFloat apertureRatio = apertureSize.height / apertureSize.width;
                CGFloat viewRatio = frameSize.width / frameSize.height;
                CGFloat xc = .5f;
                CGFloat yc = .5f;
                
                if ( [previewLayer.videoGravity isEqualToString:AVLayerVideoGravityResizeAspect] ) {
                    if (viewRatio > apertureRatio) {
                        CGFloat y2 = frameSize.height;
                        CGFloat x2 = frameSize.height * apertureRatio;
                        CGFloat x1 = frameSize.width;
                        CGFloat blackBar = (x1 - x2) / 2;
                        if (point.x >= blackBar && point.x <= blackBar + x2) {
                            xc = point.y / y2;
                            yc = 1.f - ((point.x - blackBar) / x2);
                        }
                    } else {
                        CGFloat y2 = frameSize.width / apertureRatio;
                        CGFloat y1 = frameSize.height;
                        CGFloat x2 = frameSize.width;
                        CGFloat blackBar = (y1 - y2) / 2;
                        if (point.y >= blackBar && point.y <= blackBar + y2) {
                            xc = ((point.y - blackBar) / y2);
                            yc = 1.f - (point.x / x2);
                        }
                    }
                } else if ([previewLayer.videoGravity isEqualToString:AVLayerVideoGravityResizeAspectFill]) {
                    if (viewRatio > apertureRatio) {
                        CGFloat y2 = apertureSize.width * (frameSize.width / apertureSize.height);
                        xc = (point.y + ((y2 - frameSize.height) / 2.f)) / y2;
                        yc = (frameSize.width - point.x) / frameSize.width;
                    } else {
                        CGFloat x2 = apertureSize.height * (frameSize.height / apertureSize.width);
                        yc = 1.f - ((point.x + ((x2 - frameSize.width) / 2)) / x2);
                        xc = point.y / frameSize.height;
                    }
                }
                
                pointOfInterest = CGPointMake(xc, yc);
                break;
            }
        }
    }
    
    return pointOfInterest;
}

- (UIImage *)cropImage:(UIImage *)image usingPreviewLayer:(AVCaptureVideoPreviewLayer *)previewLayer
{
    CGRect previewBounds = previewLayer.bounds;
    CGRect outputRect = [previewLayer metadataOutputRectOfInterestForRect:previewBounds];
    
    CGImageRef takenCGImage = image.CGImage;
    size_t width = CGImageGetWidth(takenCGImage);
    size_t height = CGImageGetHeight(takenCGImage);
    CGRect cropRect = CGRectMake(outputRect.origin.x * width, outputRect.origin.y * height,
                                 outputRect.size.width * width, outputRect.size.height * height);
    
    CGImageRef cropCGImage = CGImageCreateWithImageInRect(takenCGImage, cropRect);
    image = [UIImage imageWithCGImage:cropCGImage scale:1 orientation:image.imageOrientation];
    CGImageRelease(cropCGImage);
    
    return image;
}

@end