在gpupixel中自定义锐化filter

基本的结构

classCustomFilter:publicFilter{public:staticstd::shared_ptr<CustomFilter>Create();boolInit();virtualboolDoRender(boolupdateSinks=true)override;// Custom parameter settersvoidsetParameter(floatvalue);protected:CustomFilter(){};// Filter parametersfloat_parameter;};

自定义头文件

sharpen_filter.h

#pragmaonce#include"gpupixel/filter/nearby_sampling3x3_filter.h"#include"gpupixel/gpupixel_define.h"namespacegpupixel{classGPUPIXEL_APISharpenFilter:publicNearbySampling3x3Filter{public:staticstd::shared_ptr<SharpenFilter>Create();boolInit();virtualboolDoRender(boolupdateSinks=true)override;// 锐化强度：通常 0.0 到 4.0，0.0 为原图voidsetSharpness(floatsharpness);protected:SharpenFilter(){};floatsharpness_;};}// namespace gpupixel

自定义源文件

sharpen_filter.cc

#include"gpupixel/filter/sharpen_filter.h"#include"core/gpupixel_context.h"namespacegpupixel{// 锐化 Shader 逻辑：中心像素权重增加，周围像素权重减少conststd::string kSharpenFragmentShaderString=R"( precision mediump float; uniform sampler2D inputImageTexture; uniform float sharpness; varying vec2 textureCoordinate; varying vec2 vLeftTexCoord; varying vec2 vRightTexCoord; varying vec2 vTopTexCoord; varying vec2 vBottomTexCoord; void main() { vec4 centerColor = texture2D(inputImageTexture, textureCoordinate); vec3 leftColor = texture2D(inputImageTexture, vLeftTexCoord).rgb; vec3 rightColor = texture2D(inputImageTexture, vRightTexCoord).rgb; vec3 topColor = texture2D(inputImageTexture, vTopTexCoord).rgb; vec3 bottomColor = texture2D(inputImageTexture, vBottomTexCoord).rgb; // 计算周围像素的平均值贡献 // 锐化公式：Result = Center + sharpness * (Center - Average(Surrounding)) vec3 sharpenedColor = centerColor.rgb * (1.0 + 4.0 * sharpness) - (leftColor + rightColor + topColor + bottomColor) * sharpness; gl_FragColor = vec4(sharpenedColor, centerColor.a); })";std::shared_ptr<SharpenFilter>SharpenFilter::Create(){autoret=std::shared_ptr<SharpenFilter>(newSharpenFilter());gpupixel::GPUPixelContext::GetInstance()->SyncRunWithContext([&]{if(ret&&!ret->Init()){ret.reset();}});returnret;}boolSharpenFilter::Init(){if(!InitWithFragmentShaderString(kSharpenFragmentShaderString)){returnfalse;}sharpness_=0.5;// 默认中等锐化RegisterProperty("sharpness",sharpness_,"The sharpness adjustment to apply (0.0 - 4.0)",[this](float&sharpness){setSharpness(sharpness);});returntrue;}voidSharpenFilter::setSharpness(floatsharpness){sharpness_=sharpness;}boolSharpenFilter::DoRender(boolupdateSinks){filter_program_->SetUniformValue("sharpness",sharpness_);returnNearbySampling3x3Filter::DoRender(updateSinks);}}// namespace gpupixel

修改CMakeLists.txt

在 common_source_files 列表的 filter 部分（建议放在 toon_filter.cc 附近），添加你的新文件路径：

# ... 前面的文件 ...${CMAKE_CURRENT_SOURCE_DIR}/filter/toon_filter.cc${CMAKE_CURRENT_SOURCE_DIR}/filter/sharpen_filter.cc# <--- 添加这一行${CMAKE_CURRENT_SOURCE_DIR}/filter/pixellation_filter.cc# ... 后面的文件 ...

为了保持项目整洁，在下方的 public_filter_header_files 列表中也添加对应的 .h 文件：

# ...${PROJECT_SOURCE_DIR}/include/gpupixel/filter/toon_filter.h${PROJECT_SOURCE_DIR}/include/gpupixel/filter/sharpen_filter.h# <--- 添加这一行${PROJECT_SOURCE_DIR}/include/gpupixel/filter/contrast_filter.h# ...

参考

https://github.com/pixpark/gpupixel