ios - 如何在两个图像之间进行锯齿形图层分离

Question

我想合并两个图像并在它们之间添加 Zigzag 边界层。

这是一个图像示例，我想将其集成到我的应用程序中。

我怎样才能在两个图像之间实现这种错觉？ 我也试过遮蔽图像，但它没有给我正确想要的输出。

请帮我解决这个问题。 任何建议将不胜感激。 谢谢

Answer 1

希望这对仍然希望实现类似目标的人有所帮助...您可以通过下面概述的 2 个步骤完成此任务，或者如果您赶时间，请直接转到完全注释的代码，这些代码完全符合您想要实现的目标.

第 1 步:拍摄 2 张​​要合并的图像。为第一张图像创建一个锯齿形边缘的剪切贝塞尔曲线路径。从图形上下文中获取合成图像。

第 2 步: 启动一个新的图形上下文，在图形上下文中按原样绘制第二个图像(右侧)。接下来，绘制您在上面的第 1 步中收到的合成图像。接下来，使用 UIBezierpath 创建一个锯齿形路径，设置线宽并用白色描边路径。从图形上下文中获取上述样式的最终图像。仅此而已!

使用示例:

  UIImage *firstImage = [UIImage imageNamed:@"firstImage.png"];

  UIImage *secondImage = [UIImage imageNamed:@"secondImage.png"];

  self.imageView.image = [self zigZagImageFrom:firstImage secondImage:secondImage];

代码:

/*
Create image with "zigzag" separator line from 2 source images
Steps to acheive the desired output:
1: Create first image with zigzag edge on the right - change value of "width" variable as necessary to extend/reduce the visible area other than zigzag edge.
2: Draw "second image" in the context (canvas) as it is, but overlayed by first image with zigzag edge generated in the step 1 above. Draw zigzag line in desired color on the image from step2 above using the same curve path.
*/
+(UIImage *)zigZagImageFrom:(UIImage *)firstImage secondImage:(UIImage *)secondimage
{   
    CGFloat width = firstImage.size.width/2; //how much of the first image you would want to keep visible other than the zigzag edges.
    CGFloat height = firstImage.size.height;

    int totalZigzagCurves = 20;  // total no of waypoints in the zigzag path.
    CGFloat zigzagCurveWidth = width/30; // width of a single zigzag curve line.
    CGFloat zigzagCurveHeight = height/totalZigzagCurves; //height of a single zigzag curve line.

    CGFloat scale = [[UIScreen mainScreen] scale];

    UIGraphicsBeginImageContextWithOptions(firstImage.size, NO, scale);

    // -- STEP 1 --

    //We will make a clipping path in zigzag style
    UIBezierPath *zigzagPath = [[UIBezierPath alloc] init];

    //Begining point of the zigzag path
    [zigzagPath moveToPoint:CGPointMake(0, 0)];

    //draw zigzag path starting from somewhere middle on the top to bottom. - must be same for zigzag line in step 3.

    int a=-1;
    for (int i=0; i<totalZigzagCurves+2; i++) {
        [zigzagPath addLineToPoint:CGPointMake(width+(zigzagCurveWidth*a), zigzagCurveHeight*i + [self randomCurvePoint:i])];
        a= a*-1;
    }

    [zigzagPath addLineToPoint:CGPointMake(0, height)];

    //remove the remaining (right side) of image using zigzag path.
    [zigzagPath addClip];

    [firstImage drawAtPoint:CGPointMake(0, 0)];

    //Output first image with zigzag edge.
    UIImage *firstHalfOfImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();


    //We have the first image with zigzag edge. Now draw it over the second source image followed by zigzag line
    UIGraphicsBeginImageContextWithOptions(firstImage.size, YES, scale);

    // -- STEP 2 --

    //draw first & second image so that we can draw the zigzag line on it.
    [secondimage drawAtPoint:CGPointMake(0, 0)];
    [firstHalfOfImage drawAtPoint:CGPointMake(0, 0)];

    // -- STEP 3 --

    //Draw zigzag line over image using same curves.
    zigzagPath = [[UIBezierPath alloc] init];

    //Begining point of the zigzag line
    [zigzagPath moveToPoint:CGPointMake(width, -5)];

    //draw zigzag line path starting from somewhere middle on the top to bottom.
    a=-1;
    for (int i=0; i<totalZigzagCurves+2; i++) {
        [zigzagPath addLineToPoint:CGPointMake(width+(zigzagCurveWidth*a), zigzagCurveHeight*i + [self randomCurvePoint:i])];
        a= a*-1;
    }


    //Set color for zigzag line.
    [[UIColor whiteColor] setStroke];

    //Set width for zigzag line.
    [zigzagPath setLineWidth:6.0];

    //Finally, draw zigzag line over the image.
    [zigzagPath stroke];

    //Output final image with zigzag.
    UIImage *zigzagImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    //Desired output
    return zigzagImage;
}

    //To make some of the zigzag curves/waypoints with variable height
+(int)randomCurvePoint:(int)value{
    if (value == 0 ||  value == 2 ) return -8;
    else if (value == 4  ||   value == 5 || value == 17 || value == 18) return 28;
    else if (value == 16 ||  value == 8  || value == 9  || value == 19) return 2;
    else if (value == 12 ||  value == 13 || value == 14 || value == 15) return -29;
    else return 1;
}

结果示例图像: 抱歉，我无法发布上述示例代码中的示例图像。不幸的是，我需要至少 10 个信誉点才能发布图片。由于这是我的第一篇文章，所以我不能发表。

感谢您对答案投赞成票。这是结果图像:

提示:将其设为 UIImage 上的类别