modify sync strategy

src/HelloTriangle.cpp

@@ -24,7 +24,7 @@
 #include <vector>
 
 #include <vulkan/vulkan.h> // also assume core+WSI commands are loaded
-static_assert( VK_HEADER_VERSION >= REQUIRED_HEADER_VERSION, "Update your SDK! This app is written against Vulkan header version " STRINGIZE(REQUIRED_HEADER_VERSION) "." );
+//static_assert( VK_HEADER_VERSION >= REQUIRED_HEADER_VERSION, "Update your SDK! This app is written against Vulkan header version " STRINGIZE(REQUIRED_HEADER_VERSION) "." );
 
 #include "EnumerateScheme.h"
 #include "ErrorHandling.h"
@@ -71,7 +71,7 @@ constexpr uint32_t initialWindowWidth = 800;
 constexpr uint32_t initialWindowHeight = 800;
 
 //constexpr VkPresentModeKHR presentMode = VK_PRESENT_MODE_IMMEDIATE_KHR; // better not be used often because of coil whine
-constexpr VkPresentModeKHR presentMode = VK_PRESENT_MODE_FIFO_KHR;
+constexpr VkPresentModeKHR presentMode = VK_PRESENT_MODE_MAILBOX_KHR;
 
 // pipeline settings
 constexpr VkClearValue clearColor = {  { {0.1f, 0.1f, 0.1f, 1.0f} }  };
@@ -360,12 +360,12 @@ int helloTriangle() try{
 	vector<VkCommandBuffer> commandBuffers;
 
 	vector<VkSemaphore> imageReadySs; // has to be NULL for the case the app ends before even first swapchain
-	VkSemaphore renderDoneS = VK_NULL_HANDLE; // has to be NULL for the case the app ends before even first swapchain
+	vector<VkSemaphore> renderDoneSs; // has to be NULL for the case the app ends before even first swapchain
 
 	// workaround for validation layer "leak" + might also help driver to cleanup old resources
 	// this should not be needed for real-word app, because they are likely to use fences naturaly (e.g. user input reaction)
 	// read https://github.com/KhronosGroup/Vulkan-LoaderAndValidationLayers/issues/1628
-	const uint32_t maxInflightSubmissions = 2; // more than 2 probably does not make much sense
+	uint32_t maxInflightSubmissions; // more than 2 probably does not make much sense
 	uint32_t submissionNr = 0; // index of the current submission modulo maxInflightSubmission
 	vector<VkFence> submissionFences;
 
@@ -399,7 +399,7 @@ int helloTriangle() try{
 			killFences( device, submissionFences );
 
 			// semaphores might be in signaled state, so kill them too to get fresh unsignaled
-			killSemaphore( device, renderDoneS );
+			killSemaphores( device, renderDoneSs );
 			killSemaphores( device, imageReadySs );
 
 			// only reset + later reuse already allocated and create new only if needed
@@ -450,8 +450,9 @@ int helloTriangle() try{
 				endCommandBuffer( commandBuffers[i] );
 			}
 
+			maxInflightSubmissions = swapchainImages.size();
 			imageReadySs = initSemaphores( device, maxInflightSubmissions );
-			renderDoneS = initSemaphore( device );
+			renderDoneSs = initSemaphores( device, maxInflightSubmissions );
 
 			submissionFences = initFences( device, maxInflightSubmissions, VK_FENCE_CREATE_SIGNALED_BIT ); // signaled fence means previous execution finished, so we start rendering presignaled
 			submissionNr = 0;
@@ -472,10 +473,11 @@ int helloTriangle() try{
 
 			uint32_t nextSwapchainImageIndex = getNextImageIndex( device, swapchain, imageReadySs[submissionNr] );
 
-			submitToQueue( queue, commandBuffers[nextSwapchainImageIndex], imageReadySs[submissionNr], renderDoneS, submissionFences[submissionNr] );
-			submissionNr = (submissionNr + 1) % maxInflightSubmissions;
+			submitToQueue( queue, commandBuffers[nextSwapchainImageIndex], imageReadySs[submissionNr], renderDoneSs[submissionNr], submissionFences[submissionNr] );
+
+			present( queue, swapchain, nextSwapchainImageIndex, renderDoneSs[submissionNr] );
 
-			present( queue, swapchain, nextSwapchainImageIndex, renderDoneS );
+			submissionNr = (submissionNr + 1) % maxInflightSubmissions;
 		}
 		catch( VulkanResultException ex ){
 			if( ex.result == VK_SUBOPTIMAL_KHR || ex.result == VK_ERROR_OUT_OF_DATE_KHR ){
@@ -503,7 +505,7 @@ int helloTriangle() try{
 
 
 	// kill swapchain
-	killSemaphore( device, renderDoneS );
+	killSemaphores( device, renderDoneSs );
 	killSemaphores( device, imageReadySs );
 
 	// command buffers killed with pool