IOS – OpenGL ES 黑白网状效果 GPUImageCrosshatchFilter

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猿说编程[Python和C]

发布于 2023-03-26 09:41:52

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发布于 2023-03-26 09:41:52

文章被收录于专栏：猿说编程猿说编程

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.

GPUImageCrosshatchFilter GPUImage 黑白网状效果，shader 源码如下：

/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 黑白网状效果 GPUImageCrosshatchFilter
//@Time:2022/05/24 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 kGPUImageCrosshatchFragmentShaderString = SHADER_STRING
(
 varying highp vec2 textureCoordinate;

 uniform sampler2D inputImageTexture;

 uniform highp float crossHatchSpacing;
 uniform highp float lineWidth;

 const highp vec3 W = vec3(0.2125, 0.7154, 0.0721);

 void main()
 {
     highp float luminance = dot(texture2D(inputImageTexture, textureCoordinate).rgb, W);

     lowp vec4 colorToDisplay = vec4(1.0, 1.0, 1.0, 1.0);
     if (luminance < 1.00)
     {
         if (mod(textureCoordinate.x + textureCoordinate.y, crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }
     if (luminance < 0.75)
     {
         if (mod(textureCoordinate.x - textureCoordinate.y, crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }
     if (luminance < 0.50)
     {
         if (mod(textureCoordinate.x + textureCoordinate.y - (crossHatchSpacing / 2.0), crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }
     if (luminance < 0.3)
     {
         if (mod(textureCoordinate.x - textureCoordinate.y - (crossHatchSpacing / 2.0), crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }

     gl_FragColor = colorToDisplay;
 }
);
#else
NSString *const kGPUImageCrosshatchFragmentShaderString = SHADER_STRING
(
 varying vec2 textureCoordinate;

 uniform sampler2D inputImageTexture;

 uniform float crossHatchSpacing;
 uniform float lineWidth;

 const vec3 W = vec3(0.2125, 0.7154, 0.0721);

 void main()
 {
     float luminance = dot(texture2D(inputImageTexture, textureCoordinate).rgb, W);

     vec4 colorToDisplay = vec4(1.0, 1.0, 1.0, 1.0);
     if (luminance < 1.00)
     {
         if (mod(textureCoordinate.x + textureCoordinate.y, crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }
     if (luminance < 0.75)
     {
         if (mod(textureCoordinate.x - textureCoordinate.y, crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }
     if (luminance < 0.50)
     {
         if (mod(textureCoordinate.x + textureCoordinate.y - (crossHatchSpacing / 2.0), crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }
     if (luminance < 0.3)
     {
         if (mod(textureCoordinate.x - textureCoordinate.y - (crossHatchSpacing / 2.0), crossHatchSpacing) <= lineWidth)
         {
             colorToDisplay = vec4(0.0, 0.0, 0.0, 1.0);
         }
     }

     gl_FragColor = colorToDisplay;
 }
);
#endif