VulkanSwapChain.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
/*=============================================================================
    VulkanSwapChain.h: Vulkan viewport RHI definitions.
=============================================================================*/
 
#pragma once
 
#include "Containers/Array.h"
#include "VulkanConfiguration.h"
#include "VulkanThirdParty.h"
 
class FVulkanDevice;
class FVulkanFence;
class FVulkanQueue;
class FVulkanSemaphore;
class FVulkanTexture;
class FVulkanView;
enum EPixelFormat : uint8;
 
 
struct FVulkanSwapChainRecreateInfo
{
    VkSwapchainKHR SwapChain;
    VkSurfaceKHR Surface;
};
 
 
class FVulkanSwapChain
{
    FVulkanSwapChain(VkInstance InInstance, FVulkanDevice& InDevice, VkSurfaceKHR InSurface, VkSwapchainKHR InSwapChain, 
        VkSurfaceTransformFlagBitsKHR PreTransform, uint32 InWidth, uint32 InHeight, bool InIsFullscreen, uint32 NumSwapChainImages,
        int8 InLockToVsync, FVulkanPlatformWindowContext& WindowContext);
 
public:
    static FVulkanSwapChain* Create(
        VkInstance InInstance, FVulkanDevice& Device, EPixelFormat& InOutPixelFormat,
        uint32 Width, uint32 Height, bool bIsFullScreen,
        uint32* InOutDesiredNumBackBuffers, TArray<VkImage>& OutImages, int8 LockToVsync,
        FVulkanPlatformWindowContext& WindowContext, FVulkanSwapChainRecreateInfo* RecreateInfo);
 
    void Destroy(FVulkanSwapChainRecreateInfo* RecreateInfo);
 
    // Has to be negative as we use this also on other callbacks as the acquired image index
    enum class EStatus
    {
        Healthy = 0,
        OutOfDate = -1,
        SurfaceLost = -2,
    };
    EStatus Present(FVulkanQueue* PresentQueue, FVulkanSemaphore* BackBufferRenderingDoneSemaphore);
 
    void RenderThreadPacing();
    inline int8 DoesLockToVsync() { return LockToVsync; }
 
    inline VkSurfaceTransformFlagBitsKHR GetCachedSurfaceTransform() const { return PreTransform; }
 
protected:
    const VkInstance Instance;
    FVulkanDevice& Device;
 
    VkSurfaceKHR Surface = VK_NULL_HANDLE;
    VkSwapchainKHR SwapChain = VK_NULL_HANDLE;
 
    const VkSurfaceTransformFlagBitsKHR PreTransform;
 
    uint32 InternalWidth = 0;
    uint32 InternalHeight = 0;
    bool bInternalFullScreen = false;
 
    void* WindowHandle = nullptr;
        
    int32 CurrentImageIndex = -1;
    int32 SemaphoreIndex = 0;
    uint32 NumPresentCalls = 0;
    uint32 NumAcquireCalls = 0;
 
    uint32 RTPacingSampleCount = 0;
    double RTPacingPreviousFrameCPUTime = 0;
    double RTPacingSampledDeltaTimeMS = 0;
    
    double NextPresentTargetTime = 0;
 
    TArray<FVulkanSemaphore*> ImageAcquiredSemaphore;
#if VULKAN_USE_IMAGE_ACQUIRE_FENCES
    TArray<FVulkanFence*> ImageAcquiredFences;
#endif
    int8 LockToVsync = 0;
 
    uint32 PresentID = 0;
 
    int32 AcquireImageIndex(FVulkanSemaphore** OutSemaphore);
 
 
    friend class FVulkanViewport;
    friend class FVulkanQueue;
};