main.cpp

#define GLFW_INCLUDE_VULKAN
#include <GLFW/glfw3.h>

#include <iostream>
#include <stdexcept>
#include <functional>
#include <cstdlib>
#include <optional>
#include <set>

#include <cstdint>
#include <algorithm>
#include <fstream>

const int WIDTH = 800;
const int HEIGHT = 600;

const int MAX_FRAMES_IN_FLIGHT = 2;

const std::vector<const char*> validationLayers = {
	"VK_LAYER_KHRONOS_validation"
};

#ifdef NDEBUG
	const bool enableValidationLayers = false;
#else
	const bool enableValidationLayers = true;
#endif

VkResult CreateDebugUtilsMessengerEXT(VkInstance instance,
	const VkDebugUtilsMessengerCreateInfoEXT* pCreateInfo,
	const VkAllocationCallbacks* pAllocator,
	VkDebugUtilsMessengerEXT* pDebugMessenger) {
	auto func = (PFN_vkCreateDebugUtilsMessengerEXT)vkGetInstanceProcAddr(instance,
		"vkCreateDebugUtilsMessengerEXT");
	if (func != nullptr) {
		return func(instance, pCreateInfo, pAllocator, pDebugMessenger);
	}
	else {
		return VK_ERROR_EXTENSION_NOT_PRESENT;
	}
}

void DestroyDebugUtilsMessengerEXT(VkInstance instance,
	VkDebugUtilsMessengerEXT debugMessenger,
	const VkAllocationCallbacks* pAllocator) {
	auto func = (PFN_vkDestroyDebugUtilsMessengerEXT)vkGetInstanceProcAddr(instance,
		"vkDestroyDebugUtilsMessengerEXT");
	if (func != nullptr) {
		func(instance, debugMessenger, pAllocator);
	}
}

class HelloTriangleApplication {
public:
	void run() {
		initWindow();
		initVulkan();
		mainLoop();
		cleanup();
	}

private:
	GLFWwindow* window;
	VkInstance instance;
	VkDebugUtilsMessengerEXT debugMessenger;
	VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
	VkDevice device;
	VkQueue graphicsQueue;
	VkQueue presentQueue;
	VkSurfaceKHR surface;
	const std::vector<const char*> deviceExtensions = {
			VK_KHR_SWAPCHAIN_EXTENSION_NAME
	};
	VkSwapchainKHR swapChain;
	std::vector<VkImage> swapChainImages;
	VkFormat swapChainImageFormat;
	VkExtent2D swapChainExtent;
	std::vector<VkImageView> swapChainImageViews;
	VkRenderPass renderPass;
	VkPipelineLayout pipelineLayout;
	VkPipeline graphicsPipeline;
	std::vector<VkFramebuffer> swapChainFramebuffers;
	VkCommandPool commandPool;
	std::vector<VkCommandBuffer> commandBuffers;
	std::vector<VkSemaphore> imageAvailableSemaphores;
	std::vector<VkSemaphore> renderFinishedSemaphores;
	std::vector<VkFence> inFlightFences;
	size_t currentFrame = 0;


	void initWindow() {
		glfwInit();

		glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
		glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);

		window = glfwCreateWindow(WIDTH, HEIGHT, "Vulkan", nullptr, nullptr);
	}

	void getExtensions() {
		uint32_t extensionCount = 0;
		vkEnumerateInstanceExtensionProperties(nullptr, &extensionCount, nullptr);

		std::vector<VkExtensionProperties> extensions(extensionCount);
		vkEnumerateInstanceExtensionProperties(nullptr, &extensionCount, extensions.data());
		std::cout << "available extensions" << std::endl;

		for (const auto& extension : extensions) {
			std::cout << "\t" << extension.extensionName << std::endl;
		}
	}

	std::vector<const char*> getRequiredExtensions() {
		uint32_t glfwExtensionCount = 0;
		const char** glfwExtensions;
		glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);

		std::vector<const char*> extensions(glfwExtensions, glfwExtensions + glfwExtensionCount);
		
		if (enableValidationLayers) {
			extensions.push_back(VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
		}

		return extensions;
	}

	void createInstance() {
		if (enableValidationLayers && !checkValidationLayerSupport()) {
			throw std::runtime_error("validation layers requested, but not available!");
		}

		VkApplicationInfo appInfo = {};
		appInfo.sType = VK_STRUCTURE_TYPE_APPLICATION_INFO;
		appInfo.pApplicationName = "Hello Triangle";
		appInfo.applicationVersion = VK_MAKE_VERSION(1, 0, 0);
		appInfo.pEngineName = "No Engine";
		appInfo.engineVersion = VK_MAKE_VERSION(1, 0, 0);
		appInfo.apiVersion = VK_API_VERSION_1_0;

		VkInstanceCreateInfo createInfo = {};
		createInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
		createInfo.pApplicationInfo = &appInfo;

		auto extensions = getRequiredExtensions();
		createInfo.enabledExtensionCount = static_cast<uint32_t>(extensions.size());
		createInfo.ppEnabledExtensionNames = extensions.data();

		VkDebugUtilsMessengerCreateInfoEXT debugCreateInfo;
		if (enableValidationLayers) {
			createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());
			createInfo.ppEnabledLayerNames = validationLayers.data();

			populateDebugMessengerCreateInfo(debugCreateInfo);
			createInfo.pNext = (VkDebugUtilsMessengerCreateInfoEXT*) &debugCreateInfo;
		}
		else {
			createInfo.enabledLayerCount = 0;
			createInfo.pNext = nullptr;
		}

		getExtensions();

		if (vkCreateInstance(&createInfo, nullptr, &instance) != VK_SUCCESS) {
			throw std::runtime_error("failed to create instance!");
		}
	}

	bool checkValidationLayerSupport() {
		uint32_t layerCount;
		vkEnumerateInstanceLayerProperties(&layerCount, nullptr);

		std::vector<VkLayerProperties> availableLayers(layerCount);
		vkEnumerateInstanceLayerProperties(&layerCount, availableLayers.data());

		for (const char* layerName : validationLayers) {
			bool layerFound = false;

			for (const auto& layerProperties : availableLayers) {
				if (strcmp(layerName, layerProperties.layerName) == 0) {
					layerFound = true;
					break;
				}
			}

			if (!layerFound) {
				return false;
			}
		}
	}

	void initVulkan() {
		createInstance();
		setupDebugMessenger();
		createSurface();
		pickPhysicalDevice();
		createLogicalDevice();
		createSwapChain();
		createImageViews();
		createRenderPass();
		createGraphicsPipeline();
		createFramebuffers();
		createCommandPool();
		createCommandBuffers();
		createSyncObjects();
	}

	void createSurface() {
		if (glfwCreateWindowSurface(instance, window, nullptr, &surface) != VK_SUCCESS) {
			throw std::runtime_error("failed to create window surface!");
		}
	}

	void createLogicalDevice() {
		QueueFamilyIndices indices = findQueueFamilies(physicalDevice);

		std::vector<VkDeviceQueueCreateInfo> queueCreateInfos;
		std::set<uint32_t> uniqueQueueFamilies = {indices.graphicsFamily.value(), indices.presentFamily.value()};

		float queuePriority = 1.0f;
		for (uint32_t queueFamily : uniqueQueueFamilies) {
			VkDeviceQueueCreateInfo queueCreateInfo = {};
			queueCreateInfo.sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
			queueCreateInfo.queueFamilyIndex = queueFamily;
			queueCreateInfo.queueCount = 1;
			queueCreateInfo.pQueuePriorities = &queuePriority;
			queueCreateInfos.push_back(queueCreateInfo);
		}

		VkPhysicalDeviceFeatures deviceFeatures = {};
		
		VkDeviceCreateInfo createInfo = {};
		createInfo.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
		createInfo.queueCreateInfoCount = static_cast<uint32_t>(queueCreateInfos.size());
		createInfo.pQueueCreateInfos = queueCreateInfos.data();

		createInfo.pEnabledFeatures = &deviceFeatures;

		createInfo.enabledExtensionCount = static_cast<uint32_t>(deviceExtensions.size());
		createInfo.ppEnabledExtensionNames = deviceExtensions.data();

		if (enableValidationLayers) {
			createInfo.enabledLayerCount = static_cast<uint32_t>(validationLayers.size());
			createInfo.ppEnabledLayerNames = validationLayers.data();
		}
		else {
			createInfo.enabledLayerCount = 0;
		}

		if (vkCreateDevice(physicalDevice, &createInfo, nullptr, &device) != VK_SUCCESS) {
			throw std::runtime_error("failed to create logical device!");
		}

		vkGetDeviceQueue(device, indices.graphicsFamily.value(), 0, &graphicsQueue);
		vkGetDeviceQueue(device, indices.presentFamily.value(), 0, &presentQueue);
	}

	void createSwapChain() {
		SwapChainSupportDetails swapChainSupport = querySwapChainSupport(physicalDevice);

		VkSurfaceFormatKHR surfaceFormat = chooseSwapSurfaceFormat(swapChainSupport.formats);
		VkPresentModeKHR presentMode = chooseSwapPresentMode(swapChainSupport.presentModes);
		VkExtent2D extent = chooseSwapExtent(swapChainSupport.capabilities);

		uint32_t imageCount = swapChainSupport.capabilities.minImageCount + 1;

		if (swapChainSupport.capabilities.maxImageCount > 0 && imageCount >
			swapChainSupport.capabilities.maxImageCount) {
			imageCount = swapChainSupport.capabilities.maxImageCount;
		}

		VkSwapchainCreateInfoKHR createInfo = {};
		createInfo.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
		createInfo.surface = surface;

		createInfo.minImageCount = imageCount;
		createInfo.imageFormat = surfaceFormat.format;
		createInfo.imageColorSpace = surfaceFormat.colorSpace;
		createInfo.imageExtent = extent;
		createInfo.imageArrayLayers = 1;
		createInfo.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;

		QueueFamilyIndices indices = findQueueFamilies(physicalDevice);
		uint32_t queueFamilyIndices[] = { indices.graphicsFamily.value(),
			indices.presentFamily.value() };

		if (indices.graphicsFamily != indices.presentFamily) {
			createInfo.imageSharingMode = VK_SHARING_MODE_CONCURRENT;
			createInfo.queueFamilyIndexCount = 2;
			createInfo.pQueueFamilyIndices = queueFamilyIndices;
		}
		else {
			createInfo.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
			createInfo.queueFamilyIndexCount = 0;
			createInfo.pQueueFamilyIndices = nullptr;
		}

		createInfo.preTransform = swapChainSupport.capabilities.currentTransform;
		createInfo.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;

		createInfo.presentMode = presentMode;
		createInfo.clipped = VK_TRUE;
		createInfo.oldSwapchain = VK_NULL_HANDLE;

		if (vkCreateSwapchainKHR(device, &createInfo, nullptr, &swapChain) != VK_SUCCESS) {
			throw std::runtime_error("failed to create swap chain!");
		}

		vkGetSwapchainImagesKHR(device, swapChain, &imageCount, nullptr);
		swapChainImages.resize(imageCount);
		vkGetSwapchainImagesKHR(device, swapChain, &imageCount, swapChainImages.data());

		swapChainImageFormat = surfaceFormat.format;
		swapChainExtent = extent;
	}

	void createImageViews() {
		swapChainImageViews.resize(swapChainImages.size());

		for (size_t i = 0; i < swapChainImages.size(); i++) {
			VkImageViewCreateInfo createInfo = {};
			createInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
			createInfo.image = swapChainImages[i];
			createInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
			createInfo.format = swapChainImageFormat;

			createInfo.components.r = VK_COMPONENT_SWIZZLE_IDENTITY;
			createInfo.components.g = VK_COMPONENT_SWIZZLE_IDENTITY;
			createInfo.components.b = VK_COMPONENT_SWIZZLE_IDENTITY;
			createInfo.components.a = VK_COMPONENT_SWIZZLE_IDENTITY;

			createInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
			createInfo.subresourceRange.baseMipLevel = 0;
			createInfo.subresourceRange.levelCount = 1;
			createInfo.subresourceRange.baseArrayLayer = 0;
			createInfo.subresourceRange.layerCount = 1;

			if (vkCreateImageView(device, &createInfo, nullptr, &swapChainImageViews[i]) !=
				VK_SUCCESS) {
				throw std::runtime_error("failed to create image views!");
			}
		}
	}

	VkShaderModule createShaderModule(const std::vector<char>& code) {
		VkShaderModuleCreateInfo createInfo = {};
		createInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
		createInfo.codeSize = code.size();
		createInfo.pCode = reinterpret_cast<const uint32_t*>(code.data());

		VkShaderModule shaderModule;
		if (vkCreateShaderModule(device, &createInfo, nullptr, &shaderModule) !=
			VK_SUCCESS) {
			throw std::runtime_error("failed to create shader module!");
		}

		return shaderModule;
	}

	void createRenderPass() {
		VkAttachmentDescription colorAttachment = {};
		colorAttachment.format = swapChainImageFormat;
		colorAttachment.samples = VK_SAMPLE_COUNT_1_BIT;
		colorAttachment.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		colorAttachment.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		colorAttachment.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		colorAttachment.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;

		colorAttachment.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		colorAttachment.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;

		VkAttachmentReference colorAttachmentRef = {};
		colorAttachmentRef.attachment = 0;
		colorAttachmentRef.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

		VkSubpassDescription subpass = {};
		subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		subpass.colorAttachmentCount = 1;
		subpass.pColorAttachments = &colorAttachmentRef;

		VkRenderPassCreateInfo renderPassInfo = {};
		renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
		renderPassInfo.attachmentCount = 1;
		renderPassInfo.pAttachments = &colorAttachment;
		renderPassInfo.subpassCount = 1;
		renderPassInfo.pSubpasses = &subpass;

		VkSubpassDependency dependency = {};
		dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
		dependency.dstSubpass = 0;
		dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependency.srcAccessMask = 0;
		dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | 
			VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;

		renderPassInfo.dependencyCount = 1;
		renderPassInfo.pDependencies = &dependency;

		if (vkCreateRenderPass(device, &renderPassInfo, nullptr, &renderPass) != VK_SUCCESS) {
			throw std::runtime_error("failed to create render pass!");
		}
	}

	void createGraphicsPipeline() {
		std::vector<char> vertShaderCode = readFile("shaders/vert.spv");
		std::vector<char> fragShaderCode = readFile("shaders/frag.spv");

		std::cout << "The size of the vertShaderCode is: " << vertShaderCode.size() << std::endl;
		std::cout << "The size of the fragShaderCode is: " << fragShaderCode.size() << std::endl;

		VkShaderModule vertShaderModule = createShaderModule(vertShaderCode);
		VkShaderModule fragShaderModule = createShaderModule(fragShaderCode);

		VkPipelineShaderStageCreateInfo vertShaderStageInfo = {};
		vertShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
		vertShaderStageInfo.stage = VK_SHADER_STAGE_VERTEX_BIT;

		vertShaderStageInfo.module = vertShaderModule;
		vertShaderStageInfo.pName = "main";

		VkPipelineShaderStageCreateInfo fragShaderStageInfo = {};
		fragShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
		fragShaderStageInfo.stage = VK_SHADER_STAGE_FRAGMENT_BIT;
		fragShaderStageInfo.module = fragShaderModule;
		fragShaderStageInfo.pName = "main";

		VkPipelineShaderStageCreateInfo shaderStages[] = { vertShaderStageInfo, fragShaderStageInfo };

		VkPipelineVertexInputStateCreateInfo vertexInputInfo = {};
		vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
		vertexInputInfo.vertexBindingDescriptionCount = 0;
		vertexInputInfo.pVertexBindingDescriptions = nullptr;
		vertexInputInfo.vertexAttributeDescriptionCount = 0;
		vertexInputInfo.pVertexAttributeDescriptions = nullptr;

		VkPipelineInputAssemblyStateCreateInfo inputAssembly = {};
		inputAssembly.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
		inputAssembly.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
		inputAssembly.primitiveRestartEnable = VK_FALSE;

		VkViewport viewport = {};
		viewport.x = 0.0f;
		viewport.y = 0.0f;
		viewport.width = (float)swapChainExtent.width;
		viewport.height = (float)swapChainExtent.height;
		viewport.minDepth = 0.0f;
		viewport.maxDepth = 1.0f;

		VkRect2D scissor = {};
		scissor.offset = { 0, 0 };
		scissor.extent = swapChainExtent;

		VkPipelineViewportStateCreateInfo viewportState = {};
		viewportState.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
		viewportState.viewportCount = 1;
		viewportState.pViewports = &viewport;
		viewportState.scissorCount = 1;
		viewportState.pScissors = &scissor;

		VkPipelineRasterizationStateCreateInfo rasterizer = {};
		rasterizer.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
		rasterizer.depthClampEnable = VK_FALSE;
		rasterizer.rasterizerDiscardEnable = VK_FALSE;
		rasterizer.polygonMode = VK_POLYGON_MODE_FILL;
		rasterizer.lineWidth = 1.0f;
		rasterizer.cullMode = VK_CULL_MODE_BACK_BIT;
		rasterizer.frontFace = VK_FRONT_FACE_CLOCKWISE;
		rasterizer.depthBiasEnable = VK_FALSE;
		rasterizer.depthBiasConstantFactor = 0.0f;
		rasterizer.depthBiasClamp = 0.0f;
		rasterizer.depthBiasSlopeFactor = 0.0f;

		VkPipelineMultisampleStateCreateInfo multisampling = {};
		multisampling.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
		multisampling.sampleShadingEnable = VK_FALSE;
		multisampling.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;
		multisampling.minSampleShading = 1.0f;
		multisampling.pSampleMask = nullptr;
		multisampling.alphaToCoverageEnable = VK_FALSE;
		multisampling.alphaToOneEnable = VK_FALSE;

		VkPipelineColorBlendAttachmentState colorBlendAttachment = {};
		colorBlendAttachment.colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT
			| VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;
		colorBlendAttachment.blendEnable = VK_FALSE;
		colorBlendAttachment.srcColorBlendFactor = VK_BLEND_FACTOR_ONE;
		colorBlendAttachment.dstColorBlendFactor = VK_BLEND_FACTOR_ZERO;
		colorBlendAttachment.colorBlendOp = VK_BLEND_OP_ADD;
		colorBlendAttachment.srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE;
		colorBlendAttachment.dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
		colorBlendAttachment.alphaBlendOp = VK_BLEND_OP_ADD;

		VkPipelineColorBlendStateCreateInfo colorBlending = {};
		colorBlending.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
		colorBlending.logicOpEnable = VK_FALSE;
		colorBlending.logicOp = VK_LOGIC_OP_COPY;
		colorBlending.attachmentCount = 1;
		colorBlending.pAttachments = &colorBlendAttachment;
		colorBlending.blendConstants[0] = 0.0f;
		colorBlending.blendConstants[1] = 0.0f;
		colorBlending.blendConstants[2] = 0.0f;
		colorBlending.blendConstants[3] = 0.0f;

		VkDynamicState dynamicStates[] = {
			VK_DYNAMIC_STATE_VIEWPORT,
			VK_DYNAMIC_STATE_LINE_WIDTH
		};

		VkPipelineDynamicStateCreateInfo dynamicState = {};
		dynamicState.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
		dynamicState.dynamicStateCount = 2;
		dynamicState.pDynamicStates = dynamicStates;
		
		VkPipelineLayoutCreateInfo pipelineLayoutInfo = {};
		pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
		pipelineLayoutInfo.setLayoutCount = 0;
		pipelineLayoutInfo.pSetLayouts = nullptr;
		pipelineLayoutInfo.pushConstantRangeCount = 0;
		pipelineLayoutInfo.pPushConstantRanges = nullptr;

		if (vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayout)
			!= VK_SUCCESS) {
			throw std::runtime_error("failed to create pipeline layout!");
		}

		VkGraphicsPipelineCreateInfo pipelineInfo = {};
		pipelineInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
		pipelineInfo.stageCount = 2;
		pipelineInfo.pStages = shaderStages;
		pipelineInfo.pVertexInputState = &vertexInputInfo;
		pipelineInfo.pInputAssemblyState = &inputAssembly;
		pipelineInfo.pViewportState = &viewportState;
		pipelineInfo.pRasterizationState = &rasterizer;
		pipelineInfo.pMultisampleState = &multisampling;
		pipelineInfo.pDepthStencilState = nullptr;
		pipelineInfo.pColorBlendState = &colorBlending;
		pipelineInfo.pDynamicState = nullptr;
		
		pipelineInfo.layout = pipelineLayout;

		pipelineInfo.renderPass = renderPass;
		pipelineInfo.subpass = 0;
		pipelineInfo.basePipelineHandle = VK_NULL_HANDLE;
		pipelineInfo.basePipelineIndex = -1;

		if (vkCreateGraphicsPipelines(device, VK_NULL_HANDLE, 1, &pipelineInfo, nullptr,
			&graphicsPipeline) != VK_SUCCESS) {
			throw std::runtime_error("failed to create graphics pipeline!");
		}

		vkDestroyShaderModule(device, fragShaderModule, nullptr);
		vkDestroyShaderModule(device, vertShaderModule, nullptr);
	}

	void createFramebuffers() {
		swapChainFramebuffers.resize(swapChainImageViews.size());

		for (size_t i = 0; i < swapChainImageViews.size(); i++) {
			VkImageView attachments[] = {
				swapChainImageViews[i]
			};

			VkFramebufferCreateInfo framebufferInfo = {};
			framebufferInfo.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
			framebufferInfo.renderPass = renderPass;
			framebufferInfo.attachmentCount = 1;
			framebufferInfo.pAttachments = attachments;
			framebufferInfo.width = swapChainExtent.width;
			framebufferInfo.height = swapChainExtent.height;
			framebufferInfo.layers = 1;

			if (vkCreateFramebuffer(device, &framebufferInfo, nullptr, &swapChainFramebuffers[i])
				!= VK_SUCCESS) {
				throw std::runtime_error("failed to create framebuffer!");
			}
		}
	}

	void createCommandPool() {
		QueueFamilyIndices queueFamilyIndices = findQueueFamilies(physicalDevice);

		VkCommandPoolCreateInfo poolInfo = {};
		poolInfo.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
		poolInfo.queueFamilyIndex = queueFamilyIndices.graphicsFamily.value();
		poolInfo.flags = 0;

		if (vkCreateCommandPool(device, &poolInfo, nullptr, &commandPool) != VK_SUCCESS) {
			throw std::runtime_error("failed to create command pool!");
		}
	}

	void createCommandBuffers() {
		commandBuffers.resize(swapChainFramebuffers.size());

		VkCommandBufferAllocateInfo allocInfo = {};
		allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
		allocInfo.commandPool = commandPool;
		allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
		allocInfo.commandBufferCount = (uint32_t)commandBuffers.size();

		if (vkAllocateCommandBuffers(device, &allocInfo, commandBuffers.data()) !=
			VK_SUCCESS) {
			throw std::runtime_error("failed to allocate command buffers!");
		}

		for (size_t i = 0; i < commandBuffers.size(); i++) {
			VkCommandBufferBeginInfo beginInfo = {};
			beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
			beginInfo.flags = 0;
			beginInfo.pInheritanceInfo = nullptr;

			if (vkBeginCommandBuffer(commandBuffers[i], &beginInfo) != VK_SUCCESS) {
				throw std::runtime_error("failed to begin recording command buffer!");
			}

			VkRenderPassBeginInfo renderPassInfo = {};
			renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
			renderPassInfo.renderPass = renderPass;
			renderPassInfo.framebuffer = swapChainFramebuffers[i];

			renderPassInfo.renderArea.offset = { 0, 0 };
			renderPassInfo.renderArea.extent = swapChainExtent;

			VkClearValue clearColor = { 0.0f, 0.0f, 0.0f, 1.0f };
			renderPassInfo.clearValueCount = 1;
			renderPassInfo.pClearValues = &clearColor;

			vkCmdBeginRenderPass(commandBuffers[i], &renderPassInfo, VK_SUBPASS_CONTENTS_INLINE);
			vkCmdBindPipeline(commandBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, graphicsPipeline);
			vkCmdDraw(commandBuffers[i], 3, 1, 0, 0);
			vkCmdEndRenderPass(commandBuffers[i]);

			if (vkEndCommandBuffer(commandBuffers[i]) != VK_SUCCESS) {
				throw std::runtime_error("failed to record command buffer!");
			}
		}
	}

	void createSyncObjects() {
		imageAvailableSemaphores.resize(MAX_FRAMES_IN_FLIGHT);
		renderFinishedSemaphores.resize(MAX_FRAMES_IN_FLIGHT);
		inFlightFences.resize(MAX_FRAMES_IN_FLIGHT);

		VkSemaphoreCreateInfo semaphoreInfo = {};
		semaphoreInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;

		VkFenceCreateInfo fenceInfo = {};
		fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
		fenceInfo.flags = VK_FENCE_CREATE_SIGNALED_BIT;

		for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
			if (vkCreateSemaphore(device, &semaphoreInfo, nullptr, &imageAvailableSemaphores[i])
				!= VK_SUCCESS || vkCreateSemaphore(device, &semaphoreInfo, nullptr,
					&renderFinishedSemaphores[i]) != VK_SUCCESS
				|| vkCreateFence(device, &fenceInfo, nullptr, &inFlightFences[i])
				!= VK_SUCCESS) {
				throw std::runtime_error("failed to create semaphores for a frame!");
			}
		}
	}

	static std::vector<char> readFile(const std::string& filename) {
		std::ifstream file(filename, std::ios::ate | std::ios::binary);

		if (!file.is_open()) {
			throw std::runtime_error("failed to open file!");
		}

		size_t fileSize = (size_t)file.tellg();
		std::vector<char> buffer(fileSize);

		file.seekg(0);
		file.read(buffer.data(), fileSize);
		file.close();

		return buffer;
	}

	struct QueueFamilyIndices {
		std::optional<uint32_t> graphicsFamily;
		std::optional<uint32_t> presentFamily;

		bool isComplete() {
			return graphicsFamily.has_value() && presentFamily.has_value();
		}
	};

	QueueFamilyIndices findQueueFamilies(VkPhysicalDevice device) {
		QueueFamilyIndices indices;

		uint32_t queueFamilyCount = 0;
		vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, nullptr);

		std::vector<VkQueueFamilyProperties> queueFamilies(queueFamilyCount);
		vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, queueFamilies.data());

		int i = 0;
		for (const auto& queueFamily : queueFamilies) {
			VkBool32 presentSupport = false;
			vkGetPhysicalDeviceSurfaceSupportKHR(device, i, surface, &presentSupport);

			if (queueFamily.queueCount > 0 && presentSupport) {
				indices.presentFamily = i;
			}
			
			if (queueFamily.queueCount > 0 && queueFamily.queueFlags & VK_QUEUE_GRAPHICS_BIT) {
				indices.graphicsFamily = i;
			}

			if (indices.isComplete()) {
				break;
			}

			i++;
		}

		return indices;
	}

	bool isDeviceSuitable(VkPhysicalDevice device) {
		QueueFamilyIndices indices = findQueueFamilies(device);

		bool extensionsSupported = checkDeviceExtensionSupport(device);

		bool swapChainAdequate = false;
		if (extensionsSupported) {
			SwapChainSupportDetails swapChainSupport = querySwapChainSupport(device);
			swapChainAdequate = !swapChainSupport.formats.empty() && 
				!swapChainSupport.presentModes.empty();
		}

		return indices.isComplete() && extensionsSupported && swapChainAdequate;
	}

	bool checkDeviceExtensionSupport(VkPhysicalDevice device) {
		uint32_t extensionCount;
		vkEnumerateDeviceExtensionProperties(device, nullptr, &extensionCount, nullptr);

		std::vector<VkExtensionProperties> availableExtensions(extensionCount);
		vkEnumerateDeviceExtensionProperties(device, nullptr, &extensionCount, availableExtensions.data());

		std::set<std::string> requiredExtensions(deviceExtensions.begin(), deviceExtensions.end());

		for (const auto& extension : availableExtensions) {
			requiredExtensions.erase(extension.extensionName);
		}

		return requiredExtensions.empty();
	}

	struct SwapChainSupportDetails {
		VkSurfaceCapabilitiesKHR capabilities;
		std::vector<VkSurfaceFormatKHR> formats;
		std::vector<VkPresentModeKHR> presentModes;
	};

	SwapChainSupportDetails querySwapChainSupport(VkPhysicalDevice device) {
		SwapChainSupportDetails details;

		vkGetPhysicalDeviceSurfaceCapabilitiesKHR(device, surface, &details.capabilities);

		uint32_t formatCount;
		vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, &formatCount, nullptr);

		if (formatCount != 0) {
			details.formats.resize(formatCount);
			vkGetPhysicalDeviceSurfaceFormatsKHR(device, surface, &formatCount, details.formats.data());
		}

		uint32_t presentModeCount;
		vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, &presentModeCount, nullptr);

		if (presentModeCount != 0) {
			details.presentModes.resize(presentModeCount);
			vkGetPhysicalDeviceSurfacePresentModesKHR(device, surface, &presentModeCount,
				details.presentModes.data());
		}

		return details;
	}

	VkSurfaceFormatKHR chooseSwapSurfaceFormat(const std::vector<VkSurfaceFormatKHR>& availableFormats) {
		for (const auto& availableFormat : availableFormats) {
			if (availableFormat.format == VK_FORMAT_B8G8R8A8_UNORM && availableFormat.colorSpace ==
				VK_COLOR_SPACE_SRGB_NONLINEAR_KHR) {
				return availableFormat;
			}
		}

		return availableFormats[0];
	}

	VkPresentModeKHR chooseSwapPresentMode(const std::vector<VkPresentModeKHR>& availablePresentModes) {
		for (const auto& availablePresentMode : availablePresentModes) {
			if (availablePresentMode == VK_PRESENT_MODE_MAILBOX_KHR) {
				return availablePresentMode;
			}
		}
		
		return VK_PRESENT_MODE_FIFO_KHR;
	}

	VkExtent2D chooseSwapExtent(const VkSurfaceCapabilitiesKHR& capabilities) {
		if (capabilities.currentExtent.width != UINT32_MAX) {
			return capabilities.currentExtent;
		}
		else {
			VkExtent2D actualExtent = { WIDTH, HEIGHT };

			actualExtent.width = std::max(capabilities.minImageExtent.width,
				std::min(capabilities.maxImageExtent.width, actualExtent.width));
			actualExtent.height = std::max(capabilities.minImageExtent.height,
				std::min(capabilities.maxImageExtent.height, actualExtent.height));

			return actualExtent;
		}
	}

	void pickPhysicalDevice() {
		uint32_t deviceCount = 0;
		vkEnumeratePhysicalDevices(instance, &deviceCount, nullptr);

		if (deviceCount == 0) {
			throw std::runtime_error("failed to find GPUs with Vulkan support!");
		}

		std::vector<VkPhysicalDevice> devices(deviceCount);
		vkEnumeratePhysicalDevices(instance, &deviceCount, devices.data());

		for (const auto& device : devices) {
			if (isDeviceSuitable(device)) {
				physicalDevice = device;
				break;
			}
		}

		if (physicalDevice == VK_NULL_HANDLE) {
			throw std::runtime_error("failed to find a suitable GPU!");
		}
	}

	void populateDebugMessengerCreateInfo(VkDebugUtilsMessengerCreateInfoEXT& createInfo) {
		createInfo = {};
		createInfo.sType = VK_STRUCTURE_TYPE_DEBUG_UTILS_MESSENGER_CREATE_INFO_EXT;
		createInfo.messageSeverity = VK_DEBUG_UTILS_MESSAGE_SEVERITY_VERBOSE_BIT_EXT |
			VK_DEBUG_UTILS_MESSAGE_SEVERITY_WARNING_BIT_EXT |
			VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT;
		createInfo.messageType = VK_DEBUG_UTILS_MESSAGE_TYPE_GENERAL_BIT_EXT |
			VK_DEBUG_UTILS_MESSAGE_TYPE_VALIDATION_BIT_EXT |
			VK_DEBUG_UTILS_MESSAGE_TYPE_PERFORMANCE_BIT_EXT;
		createInfo.pfnUserCallback = debugCallback;
	}

	void setupDebugMessenger() {
		if (!enableValidationLayers) return;

		VkDebugUtilsMessengerCreateInfoEXT createInfo;
		populateDebugMessengerCreateInfo(createInfo);

		if (CreateDebugUtilsMessengerEXT(instance,
			&createInfo, nullptr, &debugMessenger) != VK_SUCCESS) {
			throw std::runtime_error("failed to set up debug messenger!");
		}
	}

	void mainLoop() {
		while (!glfwWindowShouldClose(window)) {
			glfwPollEvents();
			drawFrame();
		}

		vkDeviceWaitIdle(device);
	}

	void drawFrame() {
		vkWaitForFences(device, 1, &inFlightFences[currentFrame], VK_TRUE, UINT64_MAX);
		vkResetFences(device, 1, &inFlightFences[currentFrame]);

		uint32_t imageIndex;
		vkAcquireNextImageKHR(device, swapChain, UINT64_MAX, 
			imageAvailableSemaphores[currentFrame], 
			VK_NULL_HANDLE,
			&imageIndex);

		VkSubmitInfo submitInfo = {};
		submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;

		VkSemaphore waitSemaphores[] = { imageAvailableSemaphores[currentFrame] };
		VkPipelineStageFlags waitStages[] = { VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT };
		submitInfo.waitSemaphoreCount = 1;
		submitInfo.pWaitSemaphores = waitSemaphores;
		submitInfo.pWaitDstStageMask = waitStages;
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &commandBuffers[imageIndex];

		VkSemaphore signalSemaphores[] = { renderFinishedSemaphores[currentFrame] };
		submitInfo.signalSemaphoreCount = 1;
		submitInfo.pSignalSemaphores = signalSemaphores;

		if (vkQueueSubmit(graphicsQueue, 1, &submitInfo, inFlightFences[currentFrame]) 
			!= VK_SUCCESS) {
			throw std::runtime_error("failed to submit draw command buffer!");
		}

		VkPresentInfoKHR presentInfo = {};
		presentInfo.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
		presentInfo.waitSemaphoreCount = 1;
		presentInfo.pWaitSemaphores = signalSemaphores;

		VkSwapchainKHR swapChains[] = { swapChain };
		presentInfo.swapchainCount = 1;
		presentInfo.pSwapchains = swapChains;
		presentInfo.pImageIndices = &imageIndex;
		presentInfo.pResults = nullptr;
		vkQueuePresentKHR(presentQueue, &presentInfo);

		currentFrame = (currentFrame + 1) % MAX_FRAMES_IN_FLIGHT;
	}

	void cleanup() {
		for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {
			vkDestroySemaphore(device, renderFinishedSemaphores[i], nullptr);
			vkDestroySemaphore(device, imageAvailableSemaphores[i], nullptr);
			vkDestroyFence(device, inFlightFences[i], nullptr);
		}

		vkDestroyCommandPool(device, commandPool, nullptr);
		vkDestroyPipeline(device, graphicsPipeline, nullptr);
		vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
		vkDestroyRenderPass(device, renderPass, nullptr);

		for (auto framebuffer : swapChainFramebuffers) {
			vkDestroyFramebuffer(device, framebuffer, nullptr);
		}

		for (auto imageView : swapChainImageViews) {
			vkDestroyImageView(device, imageView, nullptr);
		}
		
		vkDestroySwapchainKHR(device, swapChain, nullptr);

		vkDestroyDevice(device, nullptr);

		vkDestroySurfaceKHR(instance, surface, nullptr);

		if (enableValidationLayers) {
			DestroyDebugUtilsMessengerEXT(instance, debugMessenger, nullptr);
		}

		vkDestroyInstance(instance, nullptr);
		
		glfwDestroyWindow(window);

		glfwTerminate();
	}

	static VKAPI_ATTR VkBool32 VKAPI_CALL debugCallback(
		VkDebugUtilsMessageSeverityFlagBitsEXT messageSeverity,
		VkDebugUtilsMessageTypeFlagsEXT messageType,
		const VkDebugUtilsMessengerCallbackDataEXT* pCallbackData,
		void* pUserData) {
		std::cerr << "validation layer: " << pCallbackData->pMessage << std::endl;

		return VK_FALSE;
	}
};

int main() {
	HelloTriangleApplication app;

	try {
		app.run();
	}
	catch (const std::exception& e) {
		std::cerr << e.what() << std::endl;
		return EXIT_FAILURE;
	}

	return EXIT_SUCCESS;
}