OpenVRBackend: Track queued/visible fbs for vroverlay forwarding

Author: misyltoad

src/Backends/OpenVRBackend.cpp

@@ -212,17 +212,20 @@ namespace gamescope
         float flAlpha = 1.0f;
     };
 
-    class COpenVRPlane
+    class COpenVRPlane final : public IBackendPlane
     {
     public:
         COpenVRPlane( COpenVRConnector *pConnector );
         ~COpenVRPlane();
 
         bool Init( COpenVRPlane *pParent, COpenVRPlane *pSiblingBelow );
+        void InitAsForwarder( vr::VROverlayHandle_t hOverlay ) { m_hOverlay = hOverlay; }
 
         void Present( std::optional<OpenVRPlaneState> oState );
         void Present( const FrameInfo_t::Layer_t *pLayer );
 
+        void ForwardFramebuffer( COpenVRFb *pFb );
+
         vr::VROverlayHandle_t GetOverlay() const { return m_hOverlay; }
         vr::VROverlayHandle_t GetOverlayThumbnail() const { return m_hOverlayThumbnail; }
 
@@ -424,6 +427,17 @@ namespace gamescope
                     }
                 }
 
+                {
+                    std::scoped_lock lock{ m_mutForwarderPlanes };
+
+                    for ( std::shared_ptr<COpenVRPlane> &pPlane : m_pForwarderPlanesInFlight )
+                    {
+                        pPlane->OnPageFlip();
+                    }
+
+                    m_pForwarderPlanesInFlight.clear();
+                }
+
                 ProcessVRInput();
             }
         }
@@ -898,16 +912,31 @@ namespace gamescope
             return true;
         }
 
-        void ForwardFramebuffer( IBackendFb *pFramebuffer, const void *pData ) override
+        void ForwardFramebuffer( std::shared_ptr<IBackendPlane> &pPlane, IBackendFb *pFramebuffer, const void *pData ) override
         {
             COpenVRFb *pVRFB = static_cast<COpenVRFb *>( pFramebuffer );
 
             vr::VROverlayHandle_t hOverlay = static_cast<vr::VROverlayHandle_t>( *reinterpret_cast<const uint64_t*>( pData ) );
-            vr::SharedTextureHandle_t ulHandle = pVRFB->GetSharedTextureHandle();
-
             openvr_log.debugf( "Forwarding for overlay: %lx", (unsigned long)hOverlay );
-            vr::Texture_t texture = { (void *)&ulHandle, vr::TextureType_SharedTextureHandle, vr::ColorSpace_Gamma };
-            vr::VROverlay()->SetOverlayTexture( hOverlay, &texture );
+
+            if ( !pPlane )
+            {
+                std::shared_ptr<COpenVRPlane> pOpenVRPlane = std::make_shared<COpenVRPlane>( nullptr );
+                pOpenVRPlane->InitAsForwarder( hOverlay );
+                pPlane = pOpenVRPlane;
+            }
+
+            std::shared_ptr<COpenVRPlane> pOpenVRPlane = std::static_pointer_cast<COpenVRPlane>( pPlane );
+            assert( pOpenVRPlane->GetOverlay() == hOverlay );
+
+            pOpenVRPlane->ForwardFramebuffer( pVRFB );
+            {
+                std::scoped_lock lock{ m_mutForwarderPlanes };
+                if ( !Algorithm::Contains( m_pForwarderPlanesInFlight, pOpenVRPlane ) )
+                {
+                    m_pForwarderPlanesInFlight.emplace_back( std::move( pOpenVRPlane ) );
+                }
+            }
         }
 
         vr::IVRIPCResourceManagerClient *GetIPCResourceManager()
@@ -1334,6 +1363,9 @@ namespace gamescope
         std::shared_ptr<CLibInputHandler> m_pLibInput;
         CAsyncWaiter<CRawPointer<IWaitable>, 16> m_LibInputWaiter;
 
+        std::mutex m_mutForwarderPlanes;
+        std::vector<std::shared_ptr<COpenVRPlane>> m_pForwarderPlanesInFlight;
+
         // Threads need to go last, as they rely on the other things in the class being constructed before their code is run.
         std::thread m_FlipHandlerThread;
 	};
@@ -1681,7 +1713,7 @@ namespace gamescope
 
     COpenVRPlane::COpenVRPlane( COpenVRConnector *pConnector )
         : m_pConnector{ pConnector }
-        , m_pBackend{ pConnector->GetBackend() }
+        , m_pBackend{ pConnector ? pConnector->GetBackend() : nullptr }
     {
     }
     COpenVRPlane::~COpenVRPlane()
@@ -1888,6 +1920,19 @@ namespace gamescope
         }
     }
 
+    void COpenVRPlane::ForwardFramebuffer( COpenVRFb *pFb )
+    {
+        vr::SharedTextureHandle_t ulHandle = pFb->GetSharedTextureHandle();
+
+        vr::Texture_t texture = { (void *)&ulHandle, vr::TextureType_SharedTextureHandle, vr::ColorSpace_Gamma };
+        vr::VROverlay()->SetOverlayTexture( m_hOverlay, &texture );
+
+        {
+            std::scoped_lock lock{ m_mutFbIds };
+            m_pQueuedFbId = pFb;
+        }
+    }
+
     void COpenVRPlane::OnPageFlip()
     {
         {

src/backend.h

@@ -258,6 +258,12 @@ namespace gamescope
         virtual void SetReleasePoint( std::shared_ptr<CReleaseTimelinePoint> pReleasePoint ) = 0;
     };
 
+    class IBackendPlane
+    {
+    public:
+        virtual ~IBackendPlane() = default;
+    };
+
     class CBaseBackendFb : public IBackendFb
     {
     public:
@@ -354,7 +360,7 @@ namespace gamescope
         virtual void NotifyPhysicalInput( InputType eInputType ) = 0;
 
         virtual bool SupportsVROverlayForwarding() = 0;
-        virtual void ForwardFramebuffer( IBackendFb *pFramebuffer, const void *pData ) = 0;
+        virtual void ForwardFramebuffer( std::shared_ptr<IBackendPlane> &pPlane, IBackendFb *pFramebuffer, const void *pData ) = 0;
 
         static IBackend *Get();
         template <typename T>
@@ -387,7 +393,7 @@ namespace gamescope
         virtual void NotifyPhysicalInput( InputType eInputType ) override {}
 
         virtual bool SupportsVROverlayForwarding() override { return false; }
-        virtual void ForwardFramebuffer( IBackendFb *pFramebuffer, const void *pData ) override {}
+        virtual void ForwardFramebuffer( std::shared_ptr<IBackendPlane> &pPlane, IBackendFb *pFramebuffer, const void *pData ) override {}
     };
 
     // This is a blob of data that may be associated with

src/steamcompmgr.cpp

@@ -2441,7 +2441,7 @@ static void ForwardVROverlayTargets()
 					continue;
 
 				const uint64_t ulOverlayHandle = *w->oulTargetVROverlay;
-				GetBackend()->ForwardFramebuffer( pFb, &ulOverlayHandle );
+				GetBackend()->ForwardFramebuffer( w->pForwarderPlane, pFb, &ulOverlayHandle );
 			}
 		}
 	}
@@ -4522,6 +4522,7 @@ map_win(xwayland_ctx_t* ctx, Window id, unsigned long sequence)
 		w->appID = 0;
 
 	w->oulTargetVROverlay = get_u64_prop(ctx, w->xwayland().id, ctx->atoms.steamGamescopeVROverlayTarget);
+	w->pForwarderPlane = nullptr;
 
 	get_size_hints(ctx, w);
 
@@ -5586,6 +5587,7 @@ handle_property_notify(xwayland_ctx_t *ctx, XPropertyEvent *ev)
 		if (w)
 		{
 			w->oulTargetVROverlay = get_u64_prop(ctx, w->xwayland().id, ctx->atoms.steamGamescopeVROverlayTarget);
+			w->pForwarderPlane = nullptr;
 			MakeFocusDirty();
 			hasRepaint = true;
 		}

src/steamcompmgr_shared.hpp

@@ -157,6 +157,7 @@ struct steamcompmgr_win_t {
 	steamcompmgr_win_type_t		type;
 
 	std::optional<uint64_t> oulTargetVROverlay;
+	std::shared_ptr<gamescope::IBackendPlane> pForwarderPlane;
 
 	steamcompmgr_xwayland_win_t& xwayland() { return std::get<steamcompmgr_xwayland_win_t>(_window_types); }
 	const steamcompmgr_xwayland_win_t& xwayland() const { return std::get<steamcompmgr_xwayland_win_t>(_window_types); }