change the code to be more semantically correct

src/Cafe/HW/Latte/Renderer/Vulkan/SwapchainInfoVk.cpp

@@ -149,7 +149,7 @@ void SwapchainInfoVk::Create()
 	m_acquireIndex = 0;
 	hasDefinedSwapchainImage = false;
 
-	m_numQueued = 0;
+	m_queueDepth = 0;
 }
 
 void SwapchainInfoVk::Cleanup()
@@ -348,7 +348,7 @@ VkPresentModeKHR SwapchainInfoVk::ChoosePresentMode(const std::vector<VkPresentM
 		return VK_PRESENT_MODE_FIFO_KHR;
 	}
 
-	m_maxQueued = 1;
+	m_maxQueued = 2;
 	return VK_PRESENT_MODE_FIFO_KHR;
 }
 

src/Cafe/HW/Latte/Renderer/Vulkan/SwapchainInfoVk.h

@@ -69,8 +69,8 @@ struct SwapchainInfoVk
 	Vector2i m_desiredExtent{};
 	uint32 swapchainImageIndex = (uint32)-1;
 	uint64 m_presentId = 1;
-	uint64 m_numQueued = 0; //track consecutive present successes
-	uint64 m_maxQueued = 0; //track consecutive present successes
+	uint64 m_queueDepth = 0; //number of frames CPU is ahead of presentation
+	uint64 m_maxQueued = 0;
 
 
 	// swapchain image ringbuffer (indexed by swapchainImageIndex)

src/Cafe/HW/Latte/Renderer/Vulkan/VulkanRenderer.cpp

@@ -2640,6 +2640,16 @@ bool VulkanRenderer::AcquireNextSwapchainImage(bool mainWindow)
 	if (!UpdateSwapchainProperties(mainWindow))
 		return false;
 
+	if(UsePresentWait(chainInfo))
+	{
+		if(chainInfo.m_queueDepth >= chainInfo.m_maxQueued)
+		{
+			uint64 waitFrameId = chainInfo.m_presentId - chainInfo.m_queueDepth;
+			vkWaitForPresentKHR(m_logicalDevice, chainInfo.m_swapchain, waitFrameId, 40'000'000);
+			chainInfo.m_queueDepth--;
+		}
+	}
+
 	bool result = chainInfo.AcquireImage();
 	if (!result)
 		return false;
@@ -2677,6 +2687,11 @@ void VulkanRenderer::RecreateSwapchain(bool mainWindow, bool skipCreate)
 		ImguiInit();
 }
 
+bool VulkanRenderer::UsePresentWait(const SwapchainInfoVk& chain) const
+{
+	return m_featureControl.deviceExtensions.present_wait && chain.m_maxQueued > 0;
+}
+
 bool VulkanRenderer::UpdateSwapchainProperties(bool mainWindow)
 {
 	auto& chainInfo = GetChainInfo(mainWindow);
@@ -2748,10 +2763,8 @@ void VulkanRenderer::SwapBuffer(bool mainWindow)
 	presentInfo.waitSemaphoreCount = 1;
 	presentInfo.pWaitSemaphores = &presentSemaphore;
 
-	const bool enablePresentWait = m_featureControl.deviceExtensions.present_wait && chainInfo.m_maxQueued != 0;
-
-	// if present_wait is available, use it to limit CPU run-ahead
-	if (enablePresentWait)
+	// if present_wait is available and enabled, add frame markers to present requests
+	if (UsePresentWait(chainInfo))
 	{
 		presentId.sType = VK_STRUCTURE_TYPE_PRESENT_ID_KHR;
 		presentId.swapchainCount = 1;
@@ -2768,16 +2781,10 @@ void VulkanRenderer::SwapBuffer(bool mainWindow)
 	if(result == VK_ERROR_OUT_OF_DATE_KHR || result == VK_SUBOPTIMAL_KHR)
 		chainInfo.m_shouldRecreate = true;
 
-	if(enablePresentWait && result == VK_SUCCESS)
+	if(result == VK_SUCCESS)
 	{
-		chainInfo.m_numQueued++;
+		chainInfo.m_queueDepth++;
 		chainInfo.m_presentId++;
-		if (chainInfo.m_numQueued > chainInfo.m_maxQueued)
-		{
-			uint64 waitFrameId = chainInfo.m_presentId - chainInfo.m_numQueued;
-			vkWaitForPresentKHR(m_logicalDevice, chainInfo.m_swapchain, waitFrameId, 40'000'000);
-			chainInfo.m_numQueued--;
-		}
 	}
 
 

src/Cafe/HW/Latte/Renderer/Vulkan/VulkanRenderer.h

@@ -552,6 +552,7 @@ class VulkanRenderer : public Renderer
 	VkPipeline backbufferBlit_createGraphicsPipeline(VkDescriptorSetLayout descriptorLayout, bool padView, RendererOutputShader* shader);
 	bool AcquireNextSwapchainImage(bool mainWindow);
 	void RecreateSwapchain(bool mainWindow, bool skipCreate = false);
+	bool UsePresentWait(const SwapchainInfoVk& chain) const;
 
 	// streamout
 	void streamout_setupXfbBuffer(uint32 bufferIndex, sint32 ringBufferOffset, uint32 rangeAddr, uint32 rangeSize) override;