IOS – OpenGL ES 色彩丢失/模糊效果 GPUImageColorPackingFilter

原创

猿说编程[Python和C]

发布于 2023-03-26 09:42:31

2680

发布于 2023-03-26 09:42:31

文章被收录于专栏：猿说编程

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.

GPUImageColorPackingFilter GPUImage 色彩丢失/模糊效果，shader 源码如下：

/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 色彩丢失/模糊效果  GPUImageColorPackingFilter
//@Time:2022/05/26 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 kGPUImageColorPackingFragmentShaderString = SHADER_STRING
(
 precision lowp float;

 uniform sampler2D inputImageTexture;

 uniform mediump mat3 convolutionMatrix;

 varying highp vec2 outputTextureCoordinate;

 varying highp vec2 upperLeftInputTextureCoordinate;
 varying highp vec2 upperRightInputTextureCoordinate;
 varying highp vec2 lowerLeftInputTextureCoordinate;
 varying highp vec2 lowerRightInputTextureCoordinate;

 void main()
 {
     float upperLeftIntensity = texture2D(inputImageTexture, upperLeftInputTextureCoordinate).r;
     float upperRightIntensity = texture2D(inputImageTexture, upperRightInputTextureCoordinate).r;
     float lowerLeftIntensity = texture2D(inputImageTexture, lowerLeftInputTextureCoordinate).r;
     float lowerRightIntensity = texture2D(inputImageTexture, lowerRightInputTextureCoordinate).r;

     gl_FragColor = vec4(upperLeftIntensity, upperRightIntensity, lowerLeftIntensity, lowerRightIntensity);
 }
);
#else
NSString *const kGPUImageColorPackingFragmentShaderString = SHADER_STRING
(
 uniform sampler2D inputImageTexture;

 uniform mat3 convolutionMatrix;

 varying vec2 outputTextureCoordinate;

 varying vec2 upperLeftInputTextureCoordinate;
 varying vec2 upperRightInputTextureCoordinate;
 varying vec2 lowerLeftInputTextureCoordinate;
 varying vec2 lowerRightInputTextureCoordinate;

 void main()
 {
     float upperLeftIntensity = texture2D(inputImageTexture, upperLeftInputTextureCoordinate).r;
     float upperRightIntensity = texture2D(inputImageTexture, upperRightInputTextureCoordinate).r;
     float lowerLeftIntensity = texture2D(inputImageTexture, lowerLeftInputTextureCoordinate).r;
     float lowerRightIntensity = texture2D(inputImageTexture, lowerRightInputTextureCoordinate).r;

     gl_FragColor = vec4(upperLeftIntensity, upperRightIntensity, lowerLeftIntensity, lowerRightIntensity);
 }
);
#endif