Add VSync support to Vulkan

Source/Engine/Graphics/GPUDevice.cpp

@@ -622,6 +622,16 @@ void GPUDevice::DumpResources()
 
 extern void ClearVertexLayoutCache();
 
+bool UseVSync()
+{
+    bool vsync = Graphics::UseVSync;
+    if (CommandLine::Options.NoVSync.HasValue())
+        vsync = !CommandLine::Options.NoVSync.GetValue();
+    else if (CommandLine::Options.VSync.HasValue())
+        vsync = CommandLine::Options.VSync.GetValue();
+    return vsync;
+}
+
 void GPUDevice::preDispose()
 {
     Locker.Lock();
@@ -665,26 +675,26 @@ void GPUDevice::DrawEnd()
 {
     PROFILE_CPU_NAMED("Present");
 
-    // Check if use VSync
-    bool useVSync = Graphics::UseVSync;
-    if (CommandLine::Options.NoVSync.HasValue())
-        useVSync = !CommandLine::Options.NoVSync.GetValue();
-    else if (CommandLine::Options.VSync.HasValue())
-        useVSync = CommandLine::Options.VSync.GetValue();
-
-    // Find index of the last rendered window task (use vsync only on the last window)
-    int32 lastWindowIndex = -1;
+    // Check if use VSync (prioritize the last window, in case of multi-window in Editor)
+    bool useVSync = UseVSync();
+    int32 vsyncTask = -1;
     for (int32 i = RenderTask::Tasks.Count() - 1; i >= 0; i--)
     {
         const auto task = RenderTask::Tasks[i];
         if (task && task->LastUsedFrame == Engine::FrameCount && task->SwapChain && task->SwapChain->IsReady())
         {
-            lastWindowIndex = i;
+            vsyncTask = i;
             break;
         }
     }
+    if (_rendererType == RendererType::Vulkan && RenderTask::Tasks.Contains(_lastVSyncTask))
+    {
+        // On Vulkan, maintain the last window that was VSynced to avoid recreating swapchain too often (eg. when using context menus or tooltips)
+        vsyncTask = RenderTask::Tasks.Find(_lastVSyncTask);
+    }
 
     // Call present on all used tasks
+    _lastVSyncTask = nullptr;
     int32 presentCount = 0;
     bool anyVSync = false;
 #if COMPILE_WITH_PROFILER
@@ -696,7 +706,7 @@ void GPUDevice::DrawEnd()
         if (task && task->LastUsedFrame == Engine::FrameCount && task->SwapChain && task->SwapChain->IsReady())
         {
             bool vsync = useVSync;
-            if (lastWindowIndex != i)
+            if (vsyncTask != i)
             {
                 // Perform VSync only on the last window
                 vsync = false;
@@ -711,6 +721,8 @@ void GPUDevice::DrawEnd()
 
             anyVSync |= vsync;
             task->OnPresent(vsync);
+            if (vsync)
+                _lastVSyncTask = task;
             presentCount++;
         }
     }

Source/Engine/Graphics/GPUDevice.h

@@ -162,6 +162,7 @@ protected:
     PrivateData* _res;
     Array<GPUResource*> _resources;
     CriticalSection _resourcesLock;
+    RenderTask* _lastVSyncTask = nullptr;
 
     void OnRequestingExit();
 

Source/Engine/GraphicsDevice/Vulkan/GPUSwapChainVulkan.cpp

@@ -9,7 +9,9 @@
 #include "GPUContextVulkan.h"
 #include "CmdBufferVulkan.h"
 #include "Engine/Core/Log.h"
+#include "Engine/Engine/Engine.h"
 #include "Engine/Graphics/GPULimits.h"
+#include "Engine/Graphics/Graphics.h"
 #include "Engine/Scripting/Enums.h"
 #include "Engine/Profiler/ProfilerCPU.h"
 #include "Engine/Profiler/ProfilerMemory.h"
@@ -153,6 +155,14 @@ void GPUSwapChainVulkan::Begin(RenderTask* task)
             backBuffer.SubmitCmdBuffer = nullptr;
         }
     }
+
+    // Rebuild swapchain if need to
+    if (_vsyncPending != _vsyncCurrent)
+    {
+        LOG(Info, "Changing VSync mode to {}", _vsyncPending ? TEXT("on") : TEXT("off"));
+        _device->WaitForGPU();
+        CreateSwapChain(_width, _height);
+    }
 }
 
 bool GPUSwapChainVulkan::Resize(int32 width, int32 height)
@@ -213,6 +223,14 @@ bool GPUSwapChainVulkan::CreateSwapChain(int32 width, int32 height)
         // Flush removed resources
         _device->DeferredDeletionQueue.ReleaseResources(true);
     }
+    if (_vsyncInit)
+    {
+        // Guess the VSync value for the 1st time (Present has not been called yet)
+        extern bool UseVSync();
+        _vsyncPending = UseVSync();
+        _vsyncPending &= _window == Engine::MainWindow; // Don't use VSync on new context menus or tooltips in Editor
+        _vsyncInit = false;
+    }
     ASSERT(_surface == VK_NULL_HANDLE);
     ASSERT_LOW_LAYER(_backBuffers.Count() == 0);
 
@@ -329,14 +347,14 @@ bool GPUSwapChainVulkan::CreateSwapChain(int32 width, int32 height)
         Array<VkPresentModeKHR, InlinedAllocation<8>> presentModes;
         presentModes.Resize(presentModesCount);
         VALIDATE_VULKAN_RESULT(vkGetPhysicalDeviceSurfacePresentModesKHR(gpu, _surface, &presentModesCount, presentModes.Get()));
-        if (presentModes.Contains(VK_PRESENT_MODE_MAILBOX_KHR))
-        {
-            presentMode = VK_PRESENT_MODE_MAILBOX_KHR;
-        }
-        else if (presentModes.Contains(VK_PRESENT_MODE_IMMEDIATE_KHR))
+        if (!_vsyncPending && presentModes.Contains(VK_PRESENT_MODE_IMMEDIATE_KHR))
         {
             presentMode = VK_PRESENT_MODE_IMMEDIATE_KHR;
         }
+        else if (!_vsyncPending && presentModes.Contains(VK_PRESENT_MODE_MAILBOX_KHR))
+        {
+            presentMode = VK_PRESENT_MODE_MAILBOX_KHR;
+        }
         else if (presentModes.Contains(VK_PRESENT_MODE_FIFO_KHR))
         {
             presentMode = VK_PRESENT_MODE_FIFO_KHR;
@@ -406,6 +424,7 @@ bool GPUSwapChainVulkan::CreateSwapChain(int32 width, int32 height)
     // Cache data
     _width = width;
     _height = height;
+    _vsyncCurrent = _vsyncPending;
 
     // Setup back buffers
     {
@@ -567,6 +586,9 @@ void GPUSwapChainVulkan::Present(bool vsync)
     PROFILE_CPU();
     ZoneColor(TracyWaitZoneColor);
 
+    // Update pending VSync value based on the present mode
+    _vsyncPending = vsync;
+
     // Ensure that backbuffer has been acquired before presenting it to the window
     const auto backBuffer = (GPUTextureViewVulkan*)GetBackBufferView();
 

Source/Engine/GraphicsDevice/Vulkan/GPUSwapChainVulkan.h

@@ -65,6 +65,7 @@ private:
     int32 _currentImageIndex;
     int32 _semaphoreIndex;
     int32 _acquiredImageIndex;
+    bool _vsyncCurrent = false, _vsyncPending = false, _vsyncInit = true;
     Array<BackBufferVulkan, FixedAllocation<VULKAN_BACK_BUFFERS_COUNT_MAX>> _backBuffers;
     SemaphoreVulkan* _acquiredSemaphore;
 
@@ -75,7 +76,6 @@ public:
     /// <summary>
     /// Gets the Vulkan surface.
     /// </summary>
-    /// <returns>The surface object.</returns>
     FORCE_INLINE VkSurfaceKHR GetSurface() const
     {
         return _surface;
@@ -84,7 +84,6 @@ public:
     /// <summary>
     /// Gets the Vulkan surface swap chain.
     /// </summary>
-    /// <returns>The swap chain object.</returns>
     FORCE_INLINE VkSwapchainKHR GetSwapChain() const
     {
         return _swapChain;