renderer: fade out windows on silent moves

src/desktop/Window.cpp

@@ -31,6 +31,7 @@ PHLWINDOW CWindow::create(SP<CXWaylandSurface> surface) {
     pWindow->m_fActiveInactiveAlpha.create(g_pConfigManager->getAnimationPropertyConfig("fadeSwitch"), pWindow, AVARDAMAGE_ENTIRE);
     pWindow->m_cRealShadowColor.create(g_pConfigManager->getAnimationPropertyConfig("fadeShadow"), pWindow, AVARDAMAGE_SHADOW);
     pWindow->m_fDimPercent.create(g_pConfigManager->getAnimationPropertyConfig("fadeDim"), pWindow, AVARDAMAGE_ENTIRE);
+    pWindow->m_fMovingToWorkspaceAlpha.create(g_pConfigManager->getAnimationPropertyConfig("fadeOut"), pWindow, AVARDAMAGE_ENTIRE);
 
     pWindow->addWindowDeco(std::make_unique<CHyprDropShadowDecoration>(pWindow));
     pWindow->addWindowDeco(std::make_unique<CHyprBorderDecoration>(pWindow));
@@ -52,6 +53,7 @@ PHLWINDOW CWindow::create(SP<CXDGSurfaceResource> resource) {
     pWindow->m_fActiveInactiveAlpha.create(g_pConfigManager->getAnimationPropertyConfig("fadeSwitch"), pWindow, AVARDAMAGE_ENTIRE);
     pWindow->m_cRealShadowColor.create(g_pConfigManager->getAnimationPropertyConfig("fadeShadow"), pWindow, AVARDAMAGE_SHADOW);
     pWindow->m_fDimPercent.create(g_pConfigManager->getAnimationPropertyConfig("fadeDim"), pWindow, AVARDAMAGE_ENTIRE);
+    pWindow->m_fMovingToWorkspaceAlpha.create(g_pConfigManager->getAnimationPropertyConfig("fadeOut"), pWindow, AVARDAMAGE_ENTIRE);
 
     pWindow->addWindowDeco(std::make_unique<CHyprDropShadowDecoration>(pWindow));
     pWindow->addWindowDeco(std::make_unique<CHyprBorderDecoration>(pWindow));
@@ -407,6 +409,11 @@ void CWindow::moveToWorkspace(PHLWORKSPACE pWorkspace) {
 
     const auto  OLDWORKSPACE = m_pWorkspace;
 
+    m_iMonitorMovedFrom = OLDWORKSPACE ? OLDWORKSPACE->m_iMonitorID : -1;
+    m_fMovingToWorkspaceAlpha.setValueAndWarp(1.F);
+    m_fMovingToWorkspaceAlpha = 0.F;
+    m_fMovingToWorkspaceAlpha.setCallbackOnEnd([this](void* thisptr) { m_iMonitorMovedFrom = -1; });
+
     m_pWorkspace = pWorkspace;
 
     setAnimationsToMove();
@@ -502,6 +509,7 @@ void CWindow::onUnmap() {
     m_fAlpha.setCallbackOnEnd(unregisterVar);
     m_cRealShadowColor.setCallbackOnEnd(unregisterVar);
     m_fDimPercent.setCallbackOnEnd(unregisterVar);
+    m_fMovingToWorkspaceAlpha.setCallbackOnEnd(unregisterVar);
 
     m_vRealSize.setCallbackOnBegin(nullptr);
 
@@ -542,6 +550,7 @@ void CWindow::onMap() {
     m_fAlpha.resetAllCallbacks();
     m_cRealShadowColor.resetAllCallbacks();
     m_fDimPercent.resetAllCallbacks();
+    m_fMovingToWorkspaceAlpha.resetAllCallbacks();
 
     m_vRealPosition.registerVar();
     m_vRealSize.registerVar();
@@ -551,6 +560,7 @@ void CWindow::onMap() {
     m_fAlpha.registerVar();
     m_cRealShadowColor.registerVar();
     m_fDimPercent.registerVar();
+    m_fMovingToWorkspaceAlpha.registerVar();
 
     m_fBorderAngleAnimationProgress.setCallbackOnEnd([&](void* ptr) { onBorderAngleAnimEnd(ptr); }, false);
 

src/desktop/Window.hpp

@@ -352,6 +352,10 @@ class CWindow {
     // animated tint
     CAnimatedVariable<float> m_fDimPercent;
 
+    // animate moving to an invisible workspace
+    int                      m_iMonitorMovedFrom = -1; // -1 means not moving
+    CAnimatedVariable<float> m_fMovingToWorkspaceAlpha;
+
     // swallowing
     PHLWINDOWREF m_pSwallowed;
 

src/render/Renderer.cpp

@@ -266,6 +266,11 @@ bool CHyprRenderer::shouldRenderWindow(PHLWINDOW pWindow, CMonitor* pMonitor) {
     if (pWindow->m_bPinned)
         return true;
 
+    // if the window is being moved to a workspace that is not invisible, and the alpha is > 0.F, render it.
+    if (pWindow->m_iMonitorMovedFrom != -1 && pWindow->m_fMovingToWorkspaceAlpha.isBeingAnimated() && pWindow->m_fMovingToWorkspaceAlpha.value() > 0.F &&
+        !g_pCompositor->isWorkspaceVisible(pWindow->m_pWorkspace))
+        return true;
+
     const auto PWINDOWWORKSPACE = pWindow->m_pWorkspace;
     if (PWINDOWWORKSPACE && PWINDOWWORKSPACE->m_iMonitorID == pMonitor->ID) {
         if (PWINDOWWORKSPACE->m_vRenderOffset.isBeingAnimated() || PWINDOWWORKSPACE->m_fAlpha.isBeingAnimated() || PWINDOWWORKSPACE->m_bForceRendering)
@@ -540,9 +545,13 @@ void CHyprRenderer::renderWindow(PHLWINDOW pWindow, CMonitor* pMonitor, timespec
     if (ignoreAllGeometry)
         decorate = false;
 
+    // whether to use m_fMovingToWorkspaceAlpha, only if fading out into an invisible ws
+    const bool USE_WORKSPACE_FADE_ALPHA = pWindow->m_iMonitorMovedFrom != -1 && !g_pCompositor->isWorkspaceVisible(pWindow->m_pWorkspace);
+
     renderdata.surface   = pWindow->m_pWLSurface->resource();
     renderdata.dontRound = pWindow->isEffectiveInternalFSMode(FSMODE_FULLSCREEN) || pWindow->m_sWindowData.noRounding.valueOrDefault();
-    renderdata.fadeAlpha = pWindow->m_fAlpha.value() * (pWindow->m_bPinned ? 1.f : PWORKSPACE->m_fAlpha.value());
+    renderdata.fadeAlpha = pWindow->m_fAlpha.value() * (pWindow->m_bPinned || USE_WORKSPACE_FADE_ALPHA ? 1.f : PWORKSPACE->m_fAlpha.value()) *
+        (USE_WORKSPACE_FADE_ALPHA ? pWindow->m_fMovingToWorkspaceAlpha.value() : 1.F);
     renderdata.alpha    = pWindow->m_fActiveInactiveAlpha.value();
     renderdata.decorate = decorate && !pWindow->m_bX11DoesntWantBorders && !pWindow->isEffectiveInternalFSMode(FSMODE_FULLSCREEN);
     renderdata.rounding = ignoreAllGeometry || renderdata.dontRound ? 0 : pWindow->rounding() * pMonitor->scale;