From 948855a98442a2d04665b0ac34d0651c013d4b37 Mon Sep 17 00:00:00 2001
From: vaxerski <43317083+vaxerski@users.noreply.github.com>
Date: Thu, 20 Jul 2023 14:11:05 +0200
Subject: [PATCH] renderer: add canSkipBackBufferClear

---
 src/render/Renderer.cpp | 26 ++++++++++++++++++++++----
 src/render/Renderer.hpp |  1 +
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/render/Renderer.cpp b/src/render/Renderer.cpp
index f3656fc7..6bf783af 100644
--- a/src/render/Renderer.cpp
+++ b/src/render/Renderer.cpp
@@ -995,10 +995,12 @@ void CHyprRenderer::renderMonitor(CMonitor* pMonitor) {
         EMIT_HOOK_EVENT("render", RENDER_POST_MIRROR);
     } else {
         g_pHyprOpenGL->blend(false);
-        if (*PRENDERTEX /* inverted cfg flag */)
-            g_pHyprOpenGL->clear(CColor(17.0 / 255.0, 17.0 / 255.0, 17.0 / 255.0, 1.0));
-        else
-            g_pHyprOpenGL->clearWithTex(); // will apply the hypr "wallpaper"
+        if (!canSkipBackBufferClear(pMonitor)) {
+            if (*PRENDERTEX /* inverted cfg flag */)
+                g_pHyprOpenGL->clear(CColor(17.0 / 255.0, 17.0 / 255.0, 17.0 / 255.0, 1.0));
+            else
+                g_pHyprOpenGL->clearWithTex(); // will apply the hypr "wallpaper"
+        }
         g_pHyprOpenGL->blend(true);
 
         wlr_box renderBox = {0, 0, (int)pMonitor->vecPixelSize.x, (int)pMonitor->vecPixelSize.y};
@@ -2000,3 +2002,19 @@ void CHyprRenderer::setOccludedForBackLayers(CRegion& region, CWorkspace* pWorks
 
     region.subtract(rg);
 }
+
+bool CHyprRenderer::canSkipBackBufferClear(CMonitor* pMonitor) {
+    for (auto& ls : pMonitor->m_aLayerSurfaceLayers[ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND]) {
+        if (!ls->layerSurface)
+            continue;
+
+        if (!ls->layerSurface->surface->opaque || !(ls->alpha.fl() >= 1.f))
+            continue;
+
+        if (ls->geometry.x == pMonitor->vecPosition.x && ls->geometry.y == pMonitor->vecPosition.y && ls->geometry.width == pMonitor->vecSize.x &&
+            ls->geometry.height == pMonitor->vecSize.y)
+            return true;
+    }
+
+    return false;
+}
diff --git a/src/render/Renderer.hpp b/src/render/Renderer.hpp
index 77f063e7..badd4a45 100644
--- a/src/render/Renderer.hpp
+++ b/src/render/Renderer.hpp
@@ -52,6 +52,7 @@ class CHyprRenderer {
     std::tuple<float, float, float> getRenderTimes(CMonitor* pMonitor); // avg max min
     void                            renderLockscreen(CMonitor* pMonitor, timespec* now);
     void                            setOccludedForBackLayers(CRegion& region, CWorkspace* pWorkspace);
+    bool                            canSkipBackBufferClear(CMonitor* pMonitor);
 
     bool                            m_bWindowRequestedCursorHide = false;
     bool                            m_bBlockSurfaceFeedback      = false;