From 3a7bd8fea2ca9711da5523dc185c05ea30ec0f35 Mon Sep 17 00:00:00 2001
From: Vaxry <vaxry@vaxry.net>
Date: Sat, 4 Apr 2026 23:20:44 +0100
Subject: [PATCH] renderer: add a cm settings cache

---
 src/render/Renderer.cpp | 21 ++++++++++++++++++++-
 src/render/Renderer.hpp | 22 +++++++++++++++++-----
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/src/render/Renderer.cpp b/src/render/Renderer.cpp
index 9d9a4ddba..d32379705 100644
--- a/src/render/Renderer.cpp
+++ b/src/render/Renderer.cpp
@@ -1612,6 +1612,7 @@ void IHyprRenderer::renderSessionLockMissing(PHLMONITOR pMonitor) {
 
 bool IHyprRenderer::beginRender(PHLMONITOR pMonitor, CRegion& damage, eRenderMode mode, SP<IHLBuffer> buffer, SP<IFramebuffer> fb, bool simple) {
     m_renderPass.clear();
+    clearCMSettingsCache();
     m_renderMode          = mode;
     m_renderData.pMonitor = pMonitor;
 
@@ -1765,8 +1766,22 @@ static bool isHDR2SDR(const NColorManagement::SImageDescription& imageDescriptio
          targetImageDescription.transferFunction == NColorManagement::CM_TRANSFER_FUNCTION_GAMMA22);
 }
 
+void IHyprRenderer::clearCMSettingsCache() {
+    m_cmSettingsCache.clear();
+}
+
 SCMSettings IHyprRenderer::getCMSettings(const NColorManagement::PImageDescription imageDescription, const NColorManagement::PImageDescription targetImageDescription,
                                          SP<CWLSurfaceResource> surface, bool modifySDR, float sdrMinLuminance, int sdrMaxLuminance) {
+    const auto srcId = imageDescription->id();
+    const auto dstId = targetImageDescription->id();
+    void*      sPtr  = m_renderData.surface.get();
+
+    for (auto const& entry : m_cmSettingsCache) {
+        if (entry.srcDescId == srcId && entry.dstDescId == dstId && entry.surfacePtr == sPtr && entry.modifySDR == modifySDR && entry.sdrMinLuminance == sdrMinLuminance &&
+            entry.sdrMaxLuminance == sdrMaxLuminance)
+            return entry.settings;
+    }
+
     const auto                          sdrEOTF = NTransferFunction::fromConfig();
     NColorManagement::eTransferFunction srcTF;
 
@@ -1799,7 +1814,7 @@ SCMSettings IHyprRenderer::getCMSettings(const NColorManagement::PImageDescripti
         ((m_renderData.pMonitor->m_sdrSaturation > 0 && m_renderData.pMonitor->m_sdrSaturation != 1.0f) ||
          (m_renderData.pMonitor->m_sdrBrightness > 0 && m_renderData.pMonitor->m_sdrBrightness != 1.0f));
 
-    return {
+    auto result = SCMSettings{
         .sourceTF        = srcTF,
         .targetTF        = targetImageDescription->value().transferFunction,
         .srcTFRange      = {.min = imageDescription->value().getTFMinLuminance(needsSDRmod ? sdrMinLuminance : -1),
@@ -1818,6 +1833,10 @@ SCMSettings IHyprRenderer::getCMSettings(const NColorManagement::PImageDescripti
         .sdrSaturation           = needsSDRmod && m_renderData.pMonitor->m_sdrSaturation > 0 ? m_renderData.pMonitor->m_sdrSaturation : 1.0f,
         .sdrBrightnessMultiplier = needsSDRmod && m_renderData.pMonitor->m_sdrBrightness > 0 ? m_renderData.pMonitor->m_sdrBrightness : 1.0f,
     };
+
+    m_cmSettingsCache.push_back({srcId, dstId, sPtr, modifySDR, sdrMinLuminance, sdrMaxLuminance, result});
+
+    return result;
 }
 
 void IHyprRenderer::renderMirrored() {
diff --git a/src/render/Renderer.hpp b/src/render/Renderer.hpp
index ba0445672..d61333c78 100644
--- a/src/render/Renderer.hpp
+++ b/src/render/Renderer.hpp
@@ -191,6 +191,7 @@ namespace Render {
 
         SCMSettings                     getCMSettings(const NColorManagement::PImageDescription imageDescription, const NColorManagement::PImageDescription targetImageDescription,
                                                       SP<CWLSurfaceResource> surface = nullptr, bool modifySDR = false, float sdrMinLuminance = -1.0f, int sdrMaxLuminance = -1);
+        void                            clearCMSettingsCache();
         virtual bool                    reloadShaders(const std::string& path = "") = 0;
 
       protected:
@@ -216,11 +217,22 @@ namespace Render {
 
         SP<ITexture>         getBackground(PHLMONITOR pMonitor);
         virtual SP<ITexture> getBlurTexture(PHLMONITORREF pMonitor);
-        SP<ITexture>         m_lockDeadTexture;
-        SP<ITexture>         m_lockDead2Texture;
-        SP<ITexture>         m_lockTtyTextTexture;
-        bool                 m_monitorTransformEnabled = false; // do not modify directly
-        std::stack<bool>     m_monitorTransformStack;
+
+        struct SCMSettingsCacheEntry {
+            uint64_t    srcDescId = 0, dstDescId = 0;
+            void*       surfacePtr      = nullptr; // read-only!!
+            bool        modifySDR       = false;
+            float       sdrMinLuminance = -1.F;
+            int         sdrMaxLuminance = -1;
+            SCMSettings settings;
+        };
+        std::vector<SCMSettingsCacheEntry> m_cmSettingsCache;
+
+        SP<ITexture>                       m_lockDeadTexture;
+        SP<ITexture>                       m_lockDead2Texture;
+        SP<ITexture>                       m_lockTtyTextTexture;
+        bool                               m_monitorTransformEnabled = false; // do not modify directly
+        std::stack<bool>                   m_monitorTransformStack;
 
         // old private:
         void arrangeLayerArray(PHLMONITOR, const std::vector<PHLLSREF>&, bool, CBox*);