procedural-3d-engine/examples/offscreen/offscreen.cpp

/*
* Vulkan Example - Offscreen rendering using a separate framebuffer
*
* Copyright (C) Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include "vulkanexamplebase.h"
#include "VulkanglTFModel.h"

#define ENABLE_VALIDATION false

// Offscreen frame buffer properties
#define FB_DIM 512
#define FB_COLOR_FORMAT VK_FORMAT_R8G8B8A8_UNORM

class VulkanExample : public VulkanExampleBase
{
public:
	bool debugDisplay = false;

	struct {
		vkglTF::Model example;
		vkglTF::Model plane;
	} models;

	struct {
		vks::Buffer vsShared;
		vks::Buffer vsMirror;
		vks::Buffer vsOffScreen;
	} uniformBuffers;

	struct UBO {
		glm::mat4 projection;
		glm::mat4 view;
		glm::mat4 model;
		glm::vec4 lightPos = glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
	} uboShared;

	struct {
		VkPipeline debug;
		VkPipeline shaded;
		VkPipeline shadedOffscreen;
		VkPipeline mirror;
	} pipelines;

	struct {
		VkPipelineLayout textured;
		VkPipelineLayout shaded;
	} pipelineLayouts;

	struct {
		VkDescriptorSet offscreen;
		VkDescriptorSet mirror;
		VkDescriptorSet model;
	} descriptorSets;

	struct {
		VkDescriptorSetLayout textured;
		VkDescriptorSetLayout shaded;
	} descriptorSetLayouts;

	// Framebuffer for offscreen rendering
	struct FrameBufferAttachment {
		VkImage image;
		VkDeviceMemory mem;
		VkImageView view;
	};
	struct OffscreenPass {
		int32_t width, height;
		VkFramebuffer frameBuffer;
		FrameBufferAttachment color, depth;
		VkRenderPass renderPass;
		VkSampler sampler;
		VkDescriptorImageInfo descriptor;
	} offscreenPass;

	glm::vec3 modelPosition = glm::vec3(0.0f, -1.0f, 0.0f);
	glm::vec3 modelRotation = glm::vec3(0.0f);

	VulkanExample() : VulkanExampleBase(ENABLE_VALIDATION)
	{
		title = "Offscreen rendering";
		timerSpeed *= 0.25f;
		camera.type = Camera::CameraType::lookat;
		camera.setPosition(glm::vec3(0.0f, 1.0f, -6.0f));
		camera.setRotation(glm::vec3(-2.5f, 0.0f, 0.0f));
		camera.setRotationSpeed(0.5f);
		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);
		settings.overlay = true;
		// The scene shader uses a clipping plane, so this feature has to be enabled
		enabledFeatures.shaderClipDistance = VK_TRUE;
	}

	~VulkanExample()
	{
		// Clean up used Vulkan resources
		// Note : Inherited destructor cleans up resources stored in base class

		// Frame buffer

		// Color attachment
		vkDestroyImageView(device, offscreenPass.color.view, nullptr);
		vkDestroyImage(device, offscreenPass.color.image, nullptr);
		vkFreeMemory(device, offscreenPass.color.mem, nullptr);

		// Depth attachment
		vkDestroyImageView(device, offscreenPass.depth.view, nullptr);
		vkDestroyImage(device, offscreenPass.depth.image, nullptr);
		vkFreeMemory(device, offscreenPass.depth.mem, nullptr);

		vkDestroyRenderPass(device, offscreenPass.renderPass, nullptr);
		vkDestroySampler(device, offscreenPass.sampler, nullptr);
		vkDestroyFramebuffer(device, offscreenPass.frameBuffer, nullptr);

		vkDestroyPipeline(device, pipelines.debug, nullptr);
		vkDestroyPipeline(device, pipelines.shaded, nullptr);
		vkDestroyPipeline(device, pipelines.shadedOffscreen, nullptr);
		vkDestroyPipeline(device, pipelines.mirror, nullptr);

		vkDestroyPipelineLayout(device, pipelineLayouts.textured, nullptr);
		vkDestroyPipelineLayout(device, pipelineLayouts.shaded, nullptr);

		vkDestroyDescriptorSetLayout(device, descriptorSetLayouts.shaded, nullptr);
		vkDestroyDescriptorSetLayout(device, descriptorSetLayouts.textured, nullptr);

		// Uniform buffers
		uniformBuffers.vsShared.destroy();
		uniformBuffers.vsMirror.destroy();
		uniformBuffers.vsOffScreen.destroy();
	}

	// Setup the offscreen framebuffer for rendering the mirrored scene
	// The color attachment of this framebuffer will then be used to sample from in the fragment shader of the final pass
	void prepareOffscreen()
	{
		offscreenPass.width = FB_DIM;
		offscreenPass.height = FB_DIM;

		// Find a suitable depth format
		VkFormat fbDepthFormat;
		VkBool32 validDepthFormat = vks::tools::getSupportedDepthFormat(physicalDevice, &fbDepthFormat);
		assert(validDepthFormat);

		// Color attachment
		VkImageCreateInfo image = vks::initializers::imageCreateInfo();
		image.imageType = VK_IMAGE_TYPE_2D;
		image.format = FB_COLOR_FORMAT;
		image.extent.width = offscreenPass.width;
		image.extent.height = offscreenPass.height;
		image.extent.depth = 1;
		image.mipLevels = 1;
		image.arrayLayers = 1;
		image.samples = VK_SAMPLE_COUNT_1_BIT;
		image.tiling = VK_IMAGE_TILING_OPTIMAL;
		// We will sample directly from the color attachment
		image.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;

		VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs;

		VK_CHECK_RESULT(vkCreateImage(device, &image, nullptr, &offscreenPass.color.image));
		vkGetImageMemoryRequirements(device, offscreenPass.color.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &offscreenPass.color.mem));
		VK_CHECK_RESULT(vkBindImageMemory(device, offscreenPass.color.image, offscreenPass.color.mem, 0));

		VkImageViewCreateInfo colorImageView = vks::initializers::imageViewCreateInfo();
		colorImageView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		colorImageView.format = FB_COLOR_FORMAT;
		colorImageView.subresourceRange = {};
		colorImageView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		colorImageView.subresourceRange.baseMipLevel = 0;
		colorImageView.subresourceRange.levelCount = 1;
		colorImageView.subresourceRange.baseArrayLayer = 0;
		colorImageView.subresourceRange.layerCount = 1;
		colorImageView.image = offscreenPass.color.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &colorImageView, nullptr, &offscreenPass.color.view));

		// Create sampler to sample from the attachment in the fragment shader
		VkSamplerCreateInfo samplerInfo = vks::initializers::samplerCreateInfo();
		samplerInfo.magFilter = VK_FILTER_LINEAR;
		samplerInfo.minFilter = VK_FILTER_LINEAR;
		samplerInfo.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		samplerInfo.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerInfo.addressModeV = samplerInfo.addressModeU;
		samplerInfo.addressModeW = samplerInfo.addressModeU;
		samplerInfo.mipLodBias = 0.0f;
		samplerInfo.maxAnisotropy = 1.0f;
		samplerInfo.minLod = 0.0f;
		samplerInfo.maxLod = 1.0f;
		samplerInfo.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
		VK_CHECK_RESULT(vkCreateSampler(device, &samplerInfo, nullptr, &offscreenPass.sampler));

		// Depth stencil attachment
		image.format = fbDepthFormat;
		image.usage = VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;

		VK_CHECK_RESULT(vkCreateImage(device, &image, nullptr, &offscreenPass.depth.image));
		vkGetImageMemoryRequirements(device, offscreenPass.depth.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &offscreenPass.depth.mem));
		VK_CHECK_RESULT(vkBindImageMemory(device, offscreenPass.depth.image, offscreenPass.depth.mem, 0));

		VkImageViewCreateInfo depthStencilView = vks::initializers::imageViewCreateInfo();
		depthStencilView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		depthStencilView.format = fbDepthFormat;
		depthStencilView.flags = 0;
		depthStencilView.subresourceRange = {};
		depthStencilView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT | VK_IMAGE_ASPECT_STENCIL_BIT;
		depthStencilView.subresourceRange.baseMipLevel = 0;
		depthStencilView.subresourceRange.levelCount = 1;
		depthStencilView.subresourceRange.baseArrayLayer = 0;
		depthStencilView.subresourceRange.layerCount = 1;
		depthStencilView.image = offscreenPass.depth.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &depthStencilView, nullptr, &offscreenPass.depth.view));

		// Create a separate render pass for the offscreen rendering as it may differ from the one used for scene rendering

		std::array<VkAttachmentDescription, 2> attchmentDescriptions = {};
		// Color attachment
		attchmentDescriptions[0].format = FB_COLOR_FORMAT;
		attchmentDescriptions[0].samples = VK_SAMPLE_COUNT_1_BIT;
		attchmentDescriptions[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attchmentDescriptions[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		attchmentDescriptions[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attchmentDescriptions[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attchmentDescriptions[0].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attchmentDescriptions[0].finalLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		// Depth attachment
		attchmentDescriptions[1].format = fbDepthFormat;
		attchmentDescriptions[1].samples = VK_SAMPLE_COUNT_1_BIT;
		attchmentDescriptions[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attchmentDescriptions[1].storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attchmentDescriptions[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attchmentDescriptions[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attchmentDescriptions[1].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attchmentDescriptions[1].finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

		VkAttachmentReference colorReference = { 0, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL };
		VkAttachmentReference depthReference = { 1, VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL };

		VkSubpassDescription subpassDescription = {};
		subpassDescription.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		subpassDescription.colorAttachmentCount = 1;
		subpassDescription.pColorAttachments = &colorReference;
		subpassDescription.pDepthStencilAttachment = &depthReference;

		// Use 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_FRAGMENT_SHADER_BIT;
		dependencies[0].dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependencies[0].srcAccessMask = VK_ACCESS_SHADER_READ_BIT;
		dependencies[0].dstAccessMask = 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_FRAGMENT_SHADER_BIT;
		dependencies[1].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		dependencies[1].dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
		dependencies[1].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;

		// Create the actual renderpass
		VkRenderPassCreateInfo renderPassInfo = {};
		renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
		renderPassInfo.attachmentCount = static_cast<uint32_t>(attchmentDescriptions.size());
		renderPassInfo.pAttachments = attchmentDescriptions.data();
		renderPassInfo.subpassCount = 1;
		renderPassInfo.pSubpasses = &subpassDescription;
		renderPassInfo.dependencyCount = static_cast<uint32_t>(dependencies.size());
		renderPassInfo.pDependencies = dependencies.data();

		VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassInfo, nullptr, &offscreenPass.renderPass));

		VkImageView attachments[2];
		attachments[0] = offscreenPass.color.view;
		attachments[1] = offscreenPass.depth.view;

		VkFramebufferCreateInfo fbufCreateInfo = vks::initializers::framebufferCreateInfo();
		fbufCreateInfo.renderPass = offscreenPass.renderPass;
		fbufCreateInfo.attachmentCount = 2;
		fbufCreateInfo.pAttachments = attachments;
		fbufCreateInfo.width = offscreenPass.width;
		fbufCreateInfo.height = offscreenPass.height;
		fbufCreateInfo.layers = 1;

		VK_CHECK_RESULT(vkCreateFramebuffer(device, &fbufCreateInfo, nullptr, &offscreenPass.frameBuffer));

		// Fill a descriptor for later use in a descriptor set
		offscreenPass.descriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		offscreenPass.descriptor.imageView = offscreenPass.color.view;
		offscreenPass.descriptor.sampler = offscreenPass.sampler;
	}

	void buildCommandBuffers()
	{
		VkCommandBufferBeginInfo cmdBufInfo = vks::initializers::commandBufferBeginInfo();

		VkClearValue clearValues[2];
		VkDeviceSize offsets[1] = { 0 };

		for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
		{
			VK_CHECK_RESULT(vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo));

			/*
				First render pass: Offscreen rendering
			*/
			{
				VkClearValue clearValues[2];
				clearValues[0].color = { { 0.0f, 0.0f, 0.0f, 0.0f } };
				clearValues[1].depthStencil = { 1.0f, 0 };

				VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
				renderPassBeginInfo.renderPass = offscreenPass.renderPass;
				renderPassBeginInfo.framebuffer = offscreenPass.frameBuffer;
				renderPassBeginInfo.renderArea.extent.width = offscreenPass.width;
				renderPassBeginInfo.renderArea.extent.height = offscreenPass.height;
				renderPassBeginInfo.clearValueCount = 2;
				renderPassBeginInfo.pClearValues = clearValues;

				vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

				VkViewport viewport = vks::initializers::viewport((float)offscreenPass.width, (float)offscreenPass.height, 0.0f, 1.0f);
				vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);

				VkRect2D scissor = vks::initializers::rect2D(offscreenPass.width, offscreenPass.height, 0, 0);
				vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);

				VkDeviceSize offsets[1] = { 0 };

				// Mirrored scene
				vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.shaded, 0, 1, &descriptorSets.offscreen, 0, NULL);
				vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.shadedOffscreen);
				models.example.draw(drawCmdBuffers[i]);

				vkCmdEndRenderPass(drawCmdBuffers[i]);
			}

			/*
				Note: Explicit synchronization is not required between the render pass, as this is done implicit via sub pass dependencies
			*/

			/*
				Second render pass: Scene rendering with applied radial blur
			*/
			{
				clearValues[0].color = defaultClearColor;
				clearValues[1].depthStencil = { 1.0f, 0 };

				VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
				renderPassBeginInfo.renderPass = renderPass;
				renderPassBeginInfo.framebuffer = frameBuffers[i];
				renderPassBeginInfo.renderArea.extent.width = width;
				renderPassBeginInfo.renderArea.extent.height = height;
				renderPassBeginInfo.clearValueCount = 2;
				renderPassBeginInfo.pClearValues = clearValues;

				vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

				VkViewport viewport = vks::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
				vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);

				VkRect2D scissor = vks::initializers::rect2D(width, height, 0, 0);
				vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);

				VkDeviceSize offsets[1] = { 0 };

				if (debugDisplay)
				{
					// Display the offscreen render target
					vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.textured, 0, 1, &descriptorSets.mirror, 0, nullptr);
					vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.debug);
					vkCmdDraw(drawCmdBuffers[i], 3, 1, 0, 0);
				} else {
					// Render the scene
					// Reflection plane
					vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.textured, 0, 1, &descriptorSets.mirror, 0, nullptr);
					vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.mirror);
					models.plane.draw(drawCmdBuffers[i]);
					// Model
					vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.shaded, 0, 1, &descriptorSets.model, 0, nullptr);
					vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.shaded);
					models.example.draw(drawCmdBuffers[i]);
				}

				drawUI(drawCmdBuffers[i]);

				vkCmdEndRenderPass(drawCmdBuffers[i]);
			}

			VK_CHECK_RESULT(vkEndCommandBuffer(drawCmdBuffers[i]));
		}
	}

	void loadAssets()
	{
		const uint32_t glTFLoadingFlags = vkglTF::FileLoadingFlags::PreTransformVertices | vkglTF::FileLoadingFlags::PreMultiplyVertexColors | vkglTF::FileLoadingFlags::FlipY;
		models.plane.loadFromFile(getAssetPath() + "models/plane.gltf", vulkanDevice, queue, glTFLoadingFlags);
		models.example.loadFromFile(getAssetPath() + "models/chinesedragon.gltf", vulkanDevice, queue, glTFLoadingFlags);
	}

	void setupDescriptorPool()
	{
		std::vector<VkDescriptorPoolSize> poolSizes = {
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 6),
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 8)
		};
		VkDescriptorPoolCreateInfo descriptorPoolInfo = vks::initializers::descriptorPoolCreateInfo(poolSizes, 5);
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));
	}

	void setupDescriptorSetLayout()
	{
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings;
		VkDescriptorSetLayoutCreateInfo descriptorLayoutInfo;
		VkPipelineLayoutCreateInfo pipelineLayoutInfo;

		// Binding 0 : Vertex shader uniform buffer
		setLayoutBindings.push_back(vks::initializers::descriptorSetLayoutBinding(
			VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
			VK_SHADER_STAGE_VERTEX_BIT,
			0));
		// Binding 1 : Fragment shader image sampler
		setLayoutBindings.push_back(vks::initializers::descriptorSetLayoutBinding(
			VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
			VK_SHADER_STAGE_FRAGMENT_BIT,
			1));
		// Binding 2 : Fragment shader image sampler
		setLayoutBindings.push_back(vks::initializers::descriptorSetLayoutBinding(
			VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
			VK_SHADER_STAGE_FRAGMENT_BIT,
			2));

		// Shaded layouts (only use first layout binding)
		descriptorLayoutInfo = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings.data(), 1);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayoutInfo, nullptr, &descriptorSetLayouts.shaded));

		pipelineLayoutInfo = vks::initializers::pipelineLayoutCreateInfo(&descriptorSetLayouts.shaded, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayouts.shaded));

		// Textured layouts (use all layout bindings)
		descriptorLayoutInfo = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings.data(), static_cast<uint32_t>(setLayoutBindings.size()));
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayoutInfo, nullptr, &descriptorSetLayouts.textured));

		pipelineLayoutInfo = vks::initializers::pipelineLayoutCreateInfo(&descriptorSetLayouts.textured, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayouts.textured));
	}

	void setupDescriptorSet()
	{
		// Mirror plane descriptor set
		VkDescriptorSetAllocateInfo allocInfo =
			vks::initializers::descriptorSetAllocateInfo(
				descriptorPool,
				&descriptorSetLayouts.textured,
				1);

		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets.mirror));

		std::vector<VkWriteDescriptorSet> writeDescriptorSets =
		{
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::writeDescriptorSet(
				descriptorSets.mirror,
				VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
				0,
				&uniformBuffers.vsMirror.descriptor),
			// Binding 1 : Fragment shader texture sampler
			vks::initializers::writeDescriptorSet(
				descriptorSets.mirror,
				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
				1,
				&offscreenPass.descriptor),
		};

		vkUpdateDescriptorSets(device, static_cast<uint32_t>(writeDescriptorSets.size()), writeDescriptorSets.data(), 0, nullptr);

		// Shaded descriptor sets
		allocInfo.pSetLayouts = &descriptorSetLayouts.shaded;

		// Model
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets.model));

		std::vector<VkWriteDescriptorSet> modelWriteDescriptorSets =
		{
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::writeDescriptorSet(
				descriptorSets.model,
				VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
				0,
				&uniformBuffers.vsShared.descriptor)
		};
		vkUpdateDescriptorSets(device, static_cast<uint32_t>(modelWriteDescriptorSets.size()), modelWriteDescriptorSets.data(), 0, nullptr);

		// Offscreen
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSets.offscreen));

		std::vector<VkWriteDescriptorSet> offScreenWriteDescriptorSets =
		{
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::writeDescriptorSet(
				descriptorSets.offscreen,
				VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
				0,
				&uniformBuffers.vsOffScreen.descriptor)
		};
		vkUpdateDescriptorSets(device, static_cast<uint32_t>(offScreenWriteDescriptorSets.size()), offScreenWriteDescriptorSets.data(), 0, nullptr);
	}

	void preparePipelines()
	{
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyState = vks::initializers::pipelineInputAssemblyStateCreateInfo(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, 0, VK_FALSE);
 		VkPipelineRasterizationStateCreateInfo rasterizationState = vks::initializers::pipelineRasterizationStateCreateInfo(VK_POLYGON_MODE_FILL, VK_CULL_MODE_BACK_BIT, VK_FRONT_FACE_COUNTER_CLOCKWISE,0);
		VkPipelineColorBlendAttachmentState blendAttachmentState = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendState = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentState);
		VkPipelineDepthStencilStateCreateInfo depthStencilState = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_TRUE, VK_TRUE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportState = vks::initializers::pipelineViewportStateCreateInfo(1, 1, 0);
		VkPipelineMultisampleStateCreateInfo multisampleState = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT, 0);
		std::vector<VkDynamicState> dynamicStateEnables = {VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR};
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages;

		VkGraphicsPipelineCreateInfo pipelineCI = vks::initializers::pipelineCreateInfo(pipelineLayouts.textured, renderPass, 0);
		pipelineCI.pInputAssemblyState = &inputAssemblyState;
		pipelineCI.pRasterizationState = &rasterizationState;
		pipelineCI.pColorBlendState = &colorBlendState;
		pipelineCI.pMultisampleState = &multisampleState;
		pipelineCI.pViewportState = &viewportState;
		pipelineCI.pDepthStencilState = &depthStencilState;
		pipelineCI.pDynamicState = &dynamicState;
		pipelineCI.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCI.pStages = shaderStages.data();
		pipelineCI.pVertexInputState = vkglTF::Vertex::getPipelineVertexInputState({vkglTF::VertexComponent::Position, vkglTF::VertexComponent::Color, vkglTF::VertexComponent::Normal});

		rasterizationState.cullMode = VK_CULL_MODE_NONE;

		// Render-target debug display
		shaderStages[0] = loadShader(getShadersPath() + "offscreen/quad.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "offscreen/quad.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.debug));

		// Mirror
		shaderStages[0] = loadShader(getShadersPath() + "offscreen/mirror.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "offscreen/mirror.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.mirror));

		rasterizationState.cullMode = VK_CULL_MODE_BACK_BIT;

		// Phong shading pipelines
		pipelineCI.layout = pipelineLayouts.shaded;
		// Scene
		shaderStages[0] = loadShader(getShadersPath() + "offscreen/phong.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "offscreen/phong.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.shaded));
		// Offscreen
		// Flip cull mode
		rasterizationState.cullMode = VK_CULL_MODE_FRONT_BIT;
		pipelineCI.renderPass = offscreenPass.renderPass;
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.shadedOffscreen));

	}

	// Prepare and initialize uniform buffer containing shader uniforms
	void prepareUniformBuffers()
	{
		// Mesh vertex shader uniform buffer block
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			&uniformBuffers.vsShared,
			sizeof(uboShared)));

		// Mirror plane vertex shader uniform buffer block
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			&uniformBuffers.vsMirror,
			sizeof(uboShared)));

		// Offscreen vertex shader uniform buffer block
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			&uniformBuffers.vsOffScreen,
			sizeof(uboShared)));

		// Map persistent
		VK_CHECK_RESULT(uniformBuffers.vsShared.map());
		VK_CHECK_RESULT(uniformBuffers.vsMirror.map());
		VK_CHECK_RESULT(uniformBuffers.vsOffScreen.map());

		updateUniformBuffers();
		updateUniformBufferOffscreen();
	}

	void updateUniformBuffers()
	{
		uboShared.projection = camera.matrices.perspective;
		uboShared.view = camera.matrices.view;

		// Model
		uboShared.model = glm::mat4(1.0f);
		uboShared.model = glm::rotate(uboShared.model, glm::radians(modelRotation.y), glm::vec3(0.0f, 1.0f, 0.0f));
		uboShared.model = glm::translate(uboShared.model, modelPosition);
		memcpy(uniformBuffers.vsShared.mapped, &uboShared, sizeof(uboShared));

		// Mirror
		uboShared.model = glm::mat4(1.0f);
		memcpy(uniformBuffers.vsMirror.mapped, &uboShared, sizeof(uboShared));
	}

	void updateUniformBufferOffscreen()
	{
		uboShared.projection = camera.matrices.perspective;
		uboShared.view = camera.matrices.view;
		uboShared.model = glm::mat4(1.0f);
		uboShared.model = glm::rotate(uboShared.model, glm::radians(modelRotation.y), glm::vec3(0.0f, 1.0f, 0.0f));
		uboShared.model = glm::scale(uboShared.model, glm::vec3(1.0f, -1.0f, 1.0f));
		uboShared.model = glm::translate(uboShared.model, modelPosition);
		memcpy(uniformBuffers.vsOffScreen.mapped, &uboShared, sizeof(uboShared));
	}

	void draw()
	{
		VulkanExampleBase::prepareFrame();

		// Command buffer to be submitted to the queue
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &drawCmdBuffers[currentBuffer];

		// Submit to queue
		VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));

		VulkanExampleBase::submitFrame();
	}

	void prepare()
	{
		VulkanExampleBase::prepare();
		loadAssets();
		prepareOffscreen();
		prepareUniformBuffers();
		setupDescriptorSetLayout();
		preparePipelines();
		setupDescriptorPool();
		setupDescriptorSet();
		buildCommandBuffers();
		prepared = true;
	}

	virtual void render()
	{
		if (!prepared)
			return;
		draw();
		if (!paused || camera.updated)
		{
			if (!paused) {
				modelRotation.y += frameTimer * 10.0f;
			}
			updateUniformBuffers();
			updateUniformBufferOffscreen();
		}
	}

	virtual void OnUpdateUIOverlay(vks::UIOverlay *overlay)
	{
		if (overlay->header("Settings")) {
			if (overlay->checkBox("Display render target", &debugDisplay)) {
				buildCommandBuffers();
			}
		}
	}
};

VULKAN_EXAMPLE_MAIN()