iOS 图片 push ios 图片叠加

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mob64ca13f7ecc9 2024-01-23 11:38:10

文章标签 iOS 图片 push OPENGL 图像处理 OPENGL ES GPUIAMGE 文章分类 iOS 移动开发

一.简介
二.效果演示
三.源码下载
四.猜你喜欢

一.简介

GPUImage 共 125 个滤镜, 分为四类

1、Color adjustments : 31 filters , 颜色处理相关 2、Image processing : 40 filters , 图像处理相关. 3、Blending modes : 29 filters , 混合模式相关. 4、Visual effects : 25 filters , 视觉效果相关.

GPUImageOverlayBlendFilter 属于 GPUImage 图像混合模式相关，用于图像叠加。shader 源码如下：

/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES GPUImage GPUImageOverlayBlendFilter
//@Time:2022/07/02 06:30
//@Motto:不积跬步无以至千里，不积小流无以成江海，程序人生的精彩需要坚持不懈地积累！
/******************************************************************************************/

#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
NSString *const kGPUImageOverlayBlendFragmentShaderString = SHADER_STRING
(
 varying highp vec2 textureCoordinate;
 varying highp vec2 textureCoordinate2;

 uniform sampler2D inputImageTexture;
 uniform sampler2D inputImageTexture2;

 void main()
 {
     mediump vec4 base = texture2D(inputImageTexture, textureCoordinate);
     mediump vec4 overlay = texture2D(inputImageTexture2, textureCoordinate2);

     mediump float ra;
     if (2.0 * base.r < base.a) {
         ra = 2.0 * overlay.r * base.r + overlay.r * (1.0 - base.a) + base.r * (1.0 - overlay.a);
     } else {
         ra = overlay.a * base.a - 2.0 * (base.a - base.r) * (overlay.a - overlay.r) + overlay.r * (1.0 - base.a) + base.r * (1.0 - overlay.a);
     }

     mediump float ga;
     if (2.0 * base.g < base.a) {
         ga = 2.0 * overlay.g * base.g + overlay.g * (1.0 - base.a) + base.g * (1.0 - overlay.a);
     } else {
         ga = overlay.a * base.a - 2.0 * (base.a - base.g) * (overlay.a - overlay.g) + overlay.g * (1.0 - base.a) + base.g * (1.0 - overlay.a);
     }

     mediump float ba;
     if (2.0 * base.b < base.a) {
         ba = 2.0 * overlay.b * base.b + overlay.b * (1.0 - base.a) + base.b * (1.0 - overlay.a);
     } else {
         ba = overlay.a * base.a - 2.0 * (base.a - base.b) * (overlay.a - overlay.b) + overlay.b * (1.0 - base.a) + base.b * (1.0 - overlay.a);
     }

     gl_FragColor = vec4(ra, ga, ba, 1.0);
 }
);
#else
NSString *const kGPUImageOverlayBlendFragmentShaderString = SHADER_STRING
(
 varying vec2 textureCoordinate;
 varying vec2 textureCoordinate2;

 uniform sampler2D inputImageTexture;
 uniform sampler2D inputImageTexture2;

 void main()
 {
     vec4 base = texture2D(inputImageTexture, textureCoordinate);
     vec4 overlay = texture2D(inputImageTexture2, textureCoordinate2);

     float ra;
     if (2.0 * base.r < base.a) {
         ra = 2.0 * overlay.r * base.r + overlay.r * (1.0 - base.a) + base.r * (1.0 - overlay.a);
     } else {
         ra = overlay.a * base.a - 2.0 * (base.a - base.r) * (overlay.a - overlay.r) + overlay.r * (1.0 - base.a) + base.r * (1.0 - overlay.a);
     }

     float ga;
     if (2.0 * base.g < base.a) {
         ga = 2.0 * overlay.g * base.g + overlay.g * (1.0 - base.a) + base.g * (1.0 - overlay.a);
     } else {
         ga = overlay.a * base.a - 2.0 * (base.a - base.g) * (overlay.a - overlay.g) + overlay.g * (1.0 - base.a) + base.g * (1.0 - overlay.a);
     }

     float ba;
     if (2.0 * base.b < base.a) {
         ba = 2.0 * overlay.b * base.b + overlay.b * (1.0 - base.a) + base.b * (1.0 - overlay.a);
     } else {
         ba = overlay.a * base.a - 2.0 * (base.a - base.b) * (overlay.a - overlay.b) + overlay.b * (1.0 - base.a) + base.b * (1.0 - overlay.a);
     }

     gl_FragColor = vec4(ra, ga, ba, 1.0);
 }
);
#endif