GammaDebugger.cpp

#include "Inspectors.h"
 
#include "InspectorGuiHelper.h"
 
#include "imgui.h"
 
namespace{
  float ConvertLinear(float C_srgb)
  {
    if(C_srgb <= 0.04045f){
      return (1.0f/12.92f) * C_srgb;
    }
    else{
      return pow((C_srgb + 0.055f)/1.055f, 2.4f);
    }
  }
  float ConvertSRGB(float C_linear)
  {
    if(C_linear < 0.0031308f){
      return 12.92f * C_linear;
    }
    else{
      return 1.055f * pow(C_linear, (1.0f/2.4f)) - 0.055f;
    }
  }
}
 
namespace Cogs::Core {
  void gammaDebugger(class Context* /*context*/, bool* show)
  {
    if (*show == false) return;
    guiBegin("Gamma Debugger", show);
 
    ImDrawList *draw_list = ImGui::GetWindowDrawList();
 
    ImGui::Text("Gamma Correct");
 
    static int test_col = (int)(ConvertSRGB(0.5f)*255);
 
    {
      ImVec2 c = ImGui::GetCursorScreenPos();
      c.x = ceil(c.x);
      c.y = ceil(c.y);
      draw_list->AddRectFilled(c, c+ImVec2(200, 200), IM_COL32(0, 0, 0, 255));
      for(int i=0; i<200; i++){
        for(int j=0; j<200; j++){
          if((i&1) != (j&1)) {
            ImVec2 p = ImVec2((float)i, (float)j);
            draw_list->AddRectFilled(c+p, c+p+ImVec2(1, 1), IM_COL32(255, 255, 255, 255));
          }
        }
      }
    }
    ImGui::Dummy(ImVec2(200, 200));
 
    ImGui::SameLine(0.0f, 0.0f);
 
    {
      ImVec2 c = ImGui::GetCursorScreenPos();
      draw_list->AddRectFilled(c, c+ImVec2(200, 200), IM_COL32(test_col, test_col, test_col, 255));
    }
    ImGui::Dummy(ImVec2(200, 200));
 
    ImGui::SliderInt("Test Color", &test_col, 0, 255);
 
    float sRGB = (float)test_col/255.0f;
    float linear = ConvertLinear(sRGB);
    ImGui::Text("sRGB: %f Linear: %f", sRGB, linear);
 
    guiEnd();
  }
}