#import "RoundAndShadowViewController.h"

#define PHOTO_HEIGHT 150

@interface RoundAndShadowViewController () {
    int method;
}


@end

@implementation RoundAndShadowViewController

/**
 当使用masksToBounds=YES的时候，再添加一个图层，只作为阴影使用，就可以解决这个问题
 */


- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    /**
     method:
     1：当为1的时候用CGContextScaleCTM(ctx, 1, -1);
        CGContextTranslateCTM(ctx, 0, -PHOTO_HEIGHT);解决倒置
     2：transform解决图片倒置问题
     3：直接赋值contents对图片直接赋值
     
     */
    method = 1;
    
    
    CGPoint position = CGPointMake(160, 200);
    CGRect bounds = CGRectMake(0, 0, PHOTO_HEIGHT, PHOTO_HEIGHT);
    CGFloat cornerRadius = PHOTO_HEIGHT/2;
    CGFloat borderWith = 2;
    
    //阴影图层
    CALayer *layerShadow = [[CALayer alloc] init];
    layerShadow.bounds = bounds;
    layerShadow.position = position;
    layerShadow.cornerRadius = cornerRadius;
    layerShadow.shadowColor = [UIColor grayColor].CGColor;
    layerShadow.shadowOffset = CGSizeMake(2, 1);
    layerShadow.shadowOpacity = 1;
    layerShadow.borderWidth = borderWith;
    layerShadow.borderColor = [UIColor whiteColor].CGColor;
    [self.view.layer addSublayer:layerShadow];
    
    //容器图层
    CALayer *layer = [[CALayer alloc] init];
    layer.bounds = bounds;
    layer.position = position;
    layer.backgroundColor = [UIColor redColor].CGColor;
    layer.cornerRadius = cornerRadius;
    layer.masksToBounds = YES;
    layer.borderColor = [UIColor whiteColor].CGColor;
    layer.borderWidth = borderWith;
    
    
#pragma mark 利用图层形变解决图像倒立问题
    if (method == 2) {
        /**
         直接利用CATransform3D类型的transform来解决图形的倒立问题
         */
        layer.transform = CATransform3DMakeRotation(M_PI, 1, 0, 0);
    }
    
    if (method == 3) {
#pragma mark 事实上，如果只是添加一张图片，就没必要这么麻烦了，直接设置contexts即可，不涉及倒立问题
        UIImage *image = [UIImage imageNamed:@"test"];
        [layer setContents:(id)image.CGImage];
    }
    
    if (method == 2||method == 1) {
        //设置图层代理
        layer.delegate = self;
        //调用图层setNeedDisplay，否则代理方法不会被调用
        [layer setNeedsDisplay];
    }
    
    //添加图层到跟图层
    [self.view.layer addSublayer:layer];
    
}

#pragma mark 绘制图形、图像到图层
- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx {
    
    if (method == 1) {
        //不用transform解决
        CGContextSaveGState(ctx);
        
        //图形上下文形变
        CGContextScaleCTM(ctx, 1, -1);
        CGContextTranslateCTM(ctx, 0, -PHOTO_HEIGHT);
        
        UIImage *image = [UIImage imageNamed:@"test"];
        //注意这个位置是相对于图层而言的不是屏幕
        CGContextDrawImage(ctx, CGRectMake(0, 0, PHOTO_HEIGHT, PHOTO_HEIGHT), image.CGImage);
        
        CGContextRestoreGState(ctx);
    } else if (method == 2) {
#pragma mark 利用transform解决倒立问题
        UIImage *image = [UIImage imageNamed:@"test"];
        CGContextDrawImage(ctx, CGRectMake(0, 0, PHOTO_HEIGHT, PHOTO_HEIGHT), image.CGImage);
    }
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end