Add ITM TF config option

Author: njdom24

src/config/ConfigDescriptions.hpp

@@ -1542,6 +1542,12 @@ inline static const std::vector<SConfigOptionDescription> CONFIG_OPTIONS = {
         .type        = CONFIG_OPTION_CHOICE,
         .data        = SConfigOptionDescription::SChoiceData{0, "disable,always,ondemand,ignore"},
     },
+    SConfigOptionDescription{
+        .value       = "render:cm_itm_tf",
+        .description = "Default transfer function for displaying untagged SDR surfaces in HDR mode. 0 - sRGB, 1 - Gamma 2.2",
+        .type        = CONFIG_OPTION_CHOICE,
+        .data        = SConfigOptionDescription::SChoiceData{0, "srgb,gamma22"},
+    },
 
     /*
      * cursor:

src/config/ConfigManager.cpp

@@ -781,6 +781,7 @@ CConfigManager::CConfigManager() {
     registerConfigVar("render:cm_auto_hdr", Hyprlang::INT{1});
     registerConfigVar("render:new_render_scheduling", Hyprlang::INT{0});
     registerConfigVar("render:non_shader_cm", Hyprlang::INT{2});
+    registerConfigVar("render:cm_itm_tf", Hyprlang::INT{0});
 
     registerConfigVar("ecosystem:no_update_news", Hyprlang::INT{0});
     registerConfigVar("ecosystem:no_donation_nag", Hyprlang::INT{0});

src/render/OpenGL.cpp

@@ -1559,8 +1559,10 @@ static bool isSDR2HDR(const NColorManagement::SImageDescription& imageDescriptio
 
 void CHyprOpenGLImpl::passCMUniforms(SShader& shader, const NColorManagement::SImageDescription& imageDescription,
                                      const NColorManagement::SImageDescription& targetImageDescription, bool modifySDR, float sdrMinLuminance, int sdrMaxLuminance) {
-    const bool needsSDRmod = modifySDR && isSDR2HDR(imageDescription, targetImageDescription);
-    if (needsSDRmod && m_renderData.surface.valid() && !m_renderData.surface->m_colorManagement.valid()) {
+    const bool  needsSDRmod = modifySDR && isSDR2HDR(imageDescription, targetImageDescription);
+    static auto PITMTF      = CConfigValue<Hyprlang::INT>("render:cm_itm_tf");
+
+    if (needsSDRmod && m_renderData.surface.valid() && !m_renderData.surface->m_colorManagement.valid() && *PITMTF == 1) {
         shader.setUniformInt(SHADER_SOURCE_TF, NColorManagement::eTransferFunction::CM_TRANSFER_FUNCTION_GAMMA22);
     } else {
     shader.setUniformInt(SHADER_SOURCE_TF, imageDescription.transferFunction);