Fold attachment layout transitions into subpass (Refs #155)

base/vulkanexamplebase.cpp

@@ -85,16 +85,8 @@ bool VulkanExampleBase::checkCommandBuffers()
 
 void VulkanExampleBase::createCommandBuffers()
 {
-	// Create one command buffer per frame buffer
+	// Create one command buffer for each swap chain image and reuse for rendering
-	// in the swap chain
-	// Command buffers store a reference to the
-	// frame buffer inside their render pass info
-	// so for static usage withouth having to rebuild
-	// them each frame, we use one per frame buffer
-
 	drawCmdBuffers.resize(swapChain.imageCount);
-	prePresentCmdBuffers.resize(swapChain.imageCount);
-	postPresentCmdBuffers.resize(swapChain.imageCount);
 
 	VkCommandBufferAllocateInfo cmdBufAllocateInfo =
 		vkTools::initializers::commandBufferAllocateInfo(
@@ -103,18 +95,11 @@ void VulkanExampleBase::createCommandBuffers()
 			static_cast<uint32_t>(drawCmdBuffers.size()));
 
 	VK_CHECK_RESULT(vkAllocateCommandBuffers(device, &cmdBufAllocateInfo, drawCmdBuffers.data()));
-
-	// Command buffers for submitting present barriers
-	// One pre and post present buffer per swap chain image
-	VK_CHECK_RESULT(vkAllocateCommandBuffers(device, &cmdBufAllocateInfo, prePresentCmdBuffers.data()));
-	VK_CHECK_RESULT(vkAllocateCommandBuffers(device, &cmdBufAllocateInfo, postPresentCmdBuffers.data()));
 }
 
 void VulkanExampleBase::destroyCommandBuffers()
 {
 	vkFreeCommandBuffers(device, cmdPool, static_cast<uint32_t>(drawCmdBuffers.size()), drawCmdBuffers.data());
-	vkFreeCommandBuffers(device, cmdPool, static_cast<uint32_t>(drawCmdBuffers.size()), prePresentCmdBuffers.data());
-	vkFreeCommandBuffers(device, cmdPool, static_cast<uint32_t>(drawCmdBuffers.size()), postPresentCmdBuffers.data());
 }
 
 void VulkanExampleBase::createSetupCommandBuffer()
@@ -220,7 +205,6 @@ void VulkanExampleBase::prepare()
 	createSetupCommandBuffer();
 	setupSwapChain();
 	createCommandBuffers();
-	buildPresentCommandBuffers();
 	setupDepthStencil();
 	setupRenderPass();
 	createPipelineCache();
@@ -625,12 +609,6 @@ void VulkanExampleBase::prepareFrame()
 {
 	// Acquire the next image from the swap chaing
 	VK_CHECK_RESULT(swapChain.acquireNextImage(semaphores.presentComplete, &currentBuffer));
-
-	// Submit post present image barrier to transform the image back to a color attachment that our render pass can write to
-	VkSubmitInfo submitInfo = vkTools::initializers::submitInfo();
-	submitInfo.commandBufferCount = 1;
-	submitInfo.pCommandBuffers = &postPresentCmdBuffers[currentBuffer];
-	VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));
 }
 
 void VulkanExampleBase::submitFrame()
@@ -667,12 +645,6 @@ void VulkanExampleBase::submitFrame()
 		submitInfo.pSignalSemaphores = &semaphores.renderComplete;
 	}
 
-	// Submit pre present image barrier to transform the image from color attachment to present(khr) for presenting to the swap chain
-	VkSubmitInfo submitInfo = vkTools::initializers::submitInfo();
-	submitInfo.commandBufferCount = 1;
-	submitInfo.pCommandBuffers = &prePresentCmdBuffers[currentBuffer];
-	VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));
-
 	VK_CHECK_RESULT(swapChain.queuePresent(queue, currentBuffer, submitTextOverlay ? semaphores.textOverlayComplete : semaphores.renderComplete));
 
 	VK_CHECK_RESULT(vkQueueWaitIdle(queue));
@@ -1472,72 +1444,6 @@ void VulkanExampleBase::buildCommandBuffers()
 	// Can be overriden in derived class
 }
 
-void VulkanExampleBase::buildPresentCommandBuffers()
-{
-	VkCommandBufferBeginInfo cmdBufInfo = vkTools::initializers::commandBufferBeginInfo();
-
-	for (uint32_t i = 0; i < swapChain.imageCount; i++)
-	{
-		// Command buffer for post present barrier
-
-		// Insert a post present image barrier to transform the image back to a
-		// color attachment that our render pass can write to
-		// We always use undefined image layout as the source as it doesn't actually matter
-		// what is done with the previous image contents
-
-		VK_CHECK_RESULT(vkBeginCommandBuffer(postPresentCmdBuffers[i], &cmdBufInfo));
-
-		VkImageMemoryBarrier postPresentBarrier = vkTools::initializers::imageMemoryBarrier();
-		postPresentBarrier.srcAccessMask = 0;
-		postPresentBarrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
-		postPresentBarrier.oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
-		postPresentBarrier.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
-		postPresentBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
-		postPresentBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
-		postPresentBarrier.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };
-		postPresentBarrier.image = swapChain.buffers[i].image;
-
-		vkCmdPipelineBarrier(
-			postPresentCmdBuffers[i],
-			VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
-			VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
-			0,
-			0, nullptr,
-			0, nullptr,
-			1, &postPresentBarrier);
-
-		VK_CHECK_RESULT(vkEndCommandBuffer(postPresentCmdBuffers[i]));
-
-		// Command buffers for pre present barrier
-
-		// Submit a pre present image barrier to the queue
-		// Transforms the (framebuffer) image layout from color attachment to present(khr) for presenting to the swap chain
-
-		VK_CHECK_RESULT(vkBeginCommandBuffer(prePresentCmdBuffers[i], &cmdBufInfo));
-
-		VkImageMemoryBarrier prePresentBarrier = vkTools::initializers::imageMemoryBarrier();
-		prePresentBarrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
-		prePresentBarrier.dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
-		prePresentBarrier.oldLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
-		prePresentBarrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
-		prePresentBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
-		prePresentBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
-		prePresentBarrier.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };
-		prePresentBarrier.image = swapChain.buffers[i].image;
-
-		vkCmdPipelineBarrier(
-			prePresentCmdBuffers[i],
-			VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
-			VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
-			VK_FLAGS_NONE,
-			0, nullptr, // No memory barriers,
-			0, nullptr, // No buffer barriers,
-			1, &prePresentBarrier);
-
-		VK_CHECK_RESULT(vkEndCommandBuffer(prePresentCmdBuffers[i]));
-	}
-}
-
 void VulkanExampleBase::createCommandPool()
 {
 	VkCommandPoolCreateInfo cmdPoolInfo = {};
@@ -1588,14 +1494,7 @@ void VulkanExampleBase::setupDepthStencil()
 	mem_alloc.allocationSize = memReqs.size;
 	mem_alloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
 	VK_CHECK_RESULT(vkAllocateMemory(device, &mem_alloc, nullptr, &depthStencil.mem));
-	
 	VK_CHECK_RESULT(vkBindImageMemory(device, depthStencil.image, depthStencil.mem, 0));
-	vkTools::setImageLayout(
-		setupCmdBuffer,
-		depthStencil.image,
-		VK_IMAGE_ASPECT_DEPTH_BIT | VK_IMAGE_ASPECT_STENCIL_BIT,
-		VK_IMAGE_LAYOUT_UNDEFINED,
-		VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL);
 
 	depthStencilView.image = depthStencil.image;
 	VK_CHECK_RESULT(vkCreateImageView(device, &depthStencilView, nullptr, &depthStencil.view));
@@ -1629,8 +1528,7 @@ void VulkanExampleBase::setupFrameBuffer()
 
 void VulkanExampleBase::setupRenderPass()
 {
-	VkAttachmentDescription attachments[2] = {};
+	std::array<VkAttachmentDescription, 2> attachments = {};
-
 	// Color attachment
 	attachments[0].format = colorformat;
 	attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
@@ -1638,9 +1536,8 @@ void VulkanExampleBase::setupRenderPass()
 	attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
 	attachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
 	attachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
-	attachments[0].initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+	attachments[0].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
-	attachments[0].finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+	attachments[0].finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
-
 	// Depth attachment
 	attachments[1].format = depthFormat;
 	attachments[1].samples = VK_SAMPLE_COUNT_1_BIT;
@@ -1648,7 +1545,7 @@ void VulkanExampleBase::setupRenderPass()
 	attachments[1].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
 	attachments[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
 	attachments[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
-	attachments[1].initialLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
+	attachments[1].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
 	attachments[1].finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
 
 	VkAttachmentReference colorReference = {};
@@ -1659,27 +1556,44 @@ void VulkanExampleBase::setupRenderPass()
 	depthReference.attachment = 1;
 	depthReference.layout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
 
-	VkSubpassDescription subpass = {};
+	VkSubpassDescription subpassDescription = {};
-	subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
+	subpassDescription.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
-	subpass.flags = 0;
+	subpassDescription.colorAttachmentCount = 1;
-	subpass.inputAttachmentCount = 0;
+	subpassDescription.pColorAttachments = &colorReference;
-	subpass.pInputAttachments = NULL;
+	subpassDescription.pDepthStencilAttachment = &depthReference;
-	subpass.colorAttachmentCount = 1;
+	subpassDescription.inputAttachmentCount = 0;
-	subpass.pColorAttachments = &colorReference;
+	subpassDescription.pInputAttachments = nullptr;
-	subpass.pResolveAttachments = NULL;
+	subpassDescription.preserveAttachmentCount = 0;
-	subpass.pDepthStencilAttachment = &depthReference;
+	subpassDescription.pPreserveAttachments = nullptr;
-	subpass.preserveAttachmentCount = 0;
+	subpassDescription.pResolveAttachments = nullptr;
-	subpass.pPreserveAttachments = NULL;
+
+	// Subpass dependencies for layout transitions
+	std::array<VkSubpassDependency, 2> dependencies;
+
+	dependencies[0].srcSubpass = VK_SUBPASS_EXTERNAL;
+	dependencies[0].dstSubpass = 0;
+	dependencies[0].srcStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
+	dependencies[0].dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+	dependencies[0].srcAccessMask = VK_ACCESS_MEMORY_READ_BIT;
+	dependencies[0].dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+	dependencies[0].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;
+
+	dependencies[1].srcSubpass = 0;
+	dependencies[1].dstSubpass = VK_SUBPASS_EXTERNAL;
+	dependencies[1].srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+	dependencies[1].dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
+	dependencies[1].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+	dependencies[1].dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
+	dependencies[1].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;
 
 	VkRenderPassCreateInfo renderPassInfo = {};
 	renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
-	renderPassInfo.pNext = NULL;
+	renderPassInfo.attachmentCount = static_cast<uint32_t>(attachments.size());
-	renderPassInfo.attachmentCount = 2;
+	renderPassInfo.pAttachments = attachments.data();
-	renderPassInfo.pAttachments = attachments;
 	renderPassInfo.subpassCount = 1;
-	renderPassInfo.pSubpasses = &subpass;
+	renderPassInfo.pSubpasses = &subpassDescription;
-	renderPassInfo.dependencyCount = 0;
+	renderPassInfo.dependencyCount = static_cast<uint32_t>(dependencies.size());
-	renderPassInfo.pDependencies = NULL;
+	renderPassInfo.pDependencies = dependencies.data();
 
 	VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassInfo, nullptr, &renderPass));
 }
@@ -1718,7 +1632,6 @@ void VulkanExampleBase::windowResize()
 	destroyCommandBuffers();
 	createCommandBuffers();
 	buildCommandBuffers();
-	buildPresentCommandBuffers();
 
 	vkQueueWaitIdle(queue);
 	vkDeviceWaitIdle(device);

base/vulkanexamplebase.h

@@ -104,10 +104,6 @@ protected:
 	VkCommandPool cmdPool;
 	// Command buffer used for setup
 	VkCommandBuffer setupCmdBuffer = VK_NULL_HANDLE;
-	// Command buffer for submitting a post present image barrier
-	std::vector<VkCommandBuffer> postPresentCmdBuffers = { VK_NULL_HANDLE };
-	// Command buffers for submitting a pre present image barrier
-	std::vector<VkCommandBuffer> prePresentCmdBuffers = { VK_NULL_HANDLE };
 	// Pipeline stage flags for the submit info structure
 	VkPipelineStageFlags submitPipelineStages = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
 	// Contains command buffers and semaphores to be presented to the queue
@@ -248,9 +244,6 @@ public:
 	// all command buffers that may reference this
 	virtual void buildCommandBuffers();
 
-	// Builds the command buffers used to submit the present barriers
-	void buildPresentCommandBuffers();
-
 	// Creates a new (graphics) command pool object storing command buffers
 	void createCommandPool();
 	// Setup default depth and stencil views
@@ -358,13 +351,11 @@ public:
 
 	// Prepare the frame for workload submission
 	// - Acquires the next image from the swap chain 
-	// - Submits a post present barrier
 	// - Sets the default wait and signal semaphores
 	void prepareFrame();
 
 	// Submit the frames' workload 
 	// - Submits the text overlay (if enabled)
-	// - 
 	void submitFrame();
 
 };