main.cpp

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

#include <iostream>
#include <fstream>
#include <stdexcept>
#include <algorithm>
#include <vector>
#include <cstring>
#include <cstdlib>
#include <cstdint>
#include <optional>
#include <set>

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"
};

const std::vector<const char*> deviceExtensions = {
	VK_KHR_SWAPCHAIN_EXTENSION_NAME
};

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

//Debug Util Messenger Creating
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;
    }
}

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

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

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

//Swap Chain Support Details
struct SwapChainSupportDetails {
    VkSurfaceCapabilitiesKHR capabilities;
    std::vector<VkSurfaceFormatKHR> formats;
    std::vector<VkPresentModeKHR> presentModes;
};

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

private:
    //GLFW variables
    GLFWwindow* window;
    
    //Vulkan Variables
    VkInstance instance;

    //Vulkan Debug Messenger
    VkDebugUtilsMessengerEXT debugMessenger;

    //VkSurface
    VkSurfaceKHR surface;

    //Physical Devices
    VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
    
	//logical device
	VkDevice device;

	//Graphics Queue
	VkQueue graphicsQueue;

    //Present Queue
    VkQueue presentQueue;

    //Swap Chain Variables
    VkSwapchainKHR swapChain;
    std::vector<VkImage> swapChainImages;
    VkFormat swapChainImageFormat;
    VkExtent2D swapChainExtent;
    std::vector<VkImageView> swapChainImageViews;

    //Render Pass
    VkRenderPass renderPass;

    //Pipeline Layout
    VkPipelineLayout pipelineLayout;

    //Graphics Pipeline
    VkPipeline graphicsPipeline;

    //Swap Chain Framebuffers
    std::vector<VkFramebuffer> swapChainFramebuffers;

    //Command Pool
    VkCommandPool commandPool;

    //Command Buffer
    std::vector<VkCommandBuffer> commandBuffers;

    //Semaphores
    //image available semaphore
    std::vector<VkSemaphore> imageAvailableSemaphores;

    //render finished semaphore
    std::vector<VkSemaphore> renderFinishedSemaphores;

    //In Flight Fences
    std::vector<VkFence> inFlightFences;

    //Current Frame
    size_t currentFrame = 0;

    void initWindow() {
        glfwInit();
        //Setting up glfw for vulkan
        glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
        glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
        
        window = glfwCreateWindow(WIDTH, HEIGHT, "Vulkan", nullptr, nullptr);
    }

    //Initializing Vulkan
    void initVulkan() {
        createInstance();
        setupDebugMessenger();
        createSurface();
        pickPhysicalDevice();
        createLogicalDevice();
        createSwapChain();
        createImageViews();
        createRenderPass();
        createGraphicsPipeline();
        createFramebuffers();
        createCommandPool();
        createCommandBuffers();
        createSyncObjects();
    }
    
    void mainLoop() {
        while(!glfwWindowShouldClose(window)) {
            glfwPollEvents();
            drawFrame();
        }
        vkDeviceWaitIdle(device);
    }

    //Clean up vulkan calls and Terminate GLFW
    void cleanup() {
        //Vulkan Calls
        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);
        
        for(auto framebuffer : swapChainFramebuffers) {
            vkDestroyFramebuffer(device, framebuffer, nullptr);
        }

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

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

        vkDestroySwapchainKHR(device, swapChain, nullptr);
        vkDestroyDevice(device, nullptr);
        
		if(enableValidationLayers) {
            DestroyDebugUtilsMessengerEXT(instance, debugMessenger, nullptr);
        }

        vkDestroySurfaceKHR(instance, surface, nullptr);
        vkDestroyInstance(instance, nullptr);

        //GLFW Calls
        glfwDestroyWindow(window);
        glfwTerminate();
    }

    //Creating vulkan instance
    void createInstance() {
        //Validation layer support check
        if(enableValidationLayers && !checkValidationLayerSupport()) {
            std::cout << "validation layers requested, but not available!" << std::endl;
        }

        //Application specific information
        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;

        //Tells vulkan driver which extensions and validation layers we want
        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;
        }

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

    //Populate Debug Messenger
    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;
    }

    //Debug Messenger Setup
    void setupDebugMessenger() {
        if(!enableValidationLayers) return;

        VkDebugUtilsMessengerCreateInfoEXT createInfo;
        populateDebugMessengerCreateInfo(createInfo);
        
        if(CreateDebugUtilsMessengerEXT(instance, &createInfo, nullptr, &debugMessenger) != VK_SUCCESS) {
            std::cout << "failed to set up debug messenger!" << std::endl;
        }
    }
    
    //Create Window Surface 
    void createSurface() {
        if(glfwCreateWindowSurface(instance, window, nullptr, &surface) != VK_SUCCESS) {
            std::cout << "failed to create window surface!" << std::endl;
        }
    }

    //Picking the graphics card
    void pickPhysicalDevice() {
        uint32_t deviceCount = 0;
        vkEnumeratePhysicalDevices(instance, &deviceCount, nullptr);

        //checks to see if their is a suitable vulkan supported card
        if(deviceCount == 0) {
            std::cout << "failed to find GPUs with Vulkan support!" << std::endl;
        }
            
        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) {
            std::cout << "failed to find a suitable GPU!" << std::endl;
        }
    }

    //Create Logical Device
    void createLogicalDevice() {
        QueueFamilyIndices indices = findQueueFamilies(physicalDevice);

        //Queue Family info
        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);
        }

        //Device Features
        VkPhysicalDeviceFeatures deviceFeatures = {};

        //Device Info
        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) {
            std::cout << "failed to create logical device!" << std::endl;
        }

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

    //Create Swap Chain
    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.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) {
            std::cout << "failed to create swap chain!" << std::endl;
        }

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

        swapChainImageFormat = surfaceFormat.format;
        swapChainExtent = extent;
    }

    //Image View Creation
    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];
            
            //Specify how the image data should be interpreted
            createInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
            createInfo.format = swapChainImageFormat;
            
            //Swizzle color channels
            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;
            
            //What part of the image should be accessed
            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) {
                std::cout << "Failed to create image views!" << std::endl;
            }
        }
    }

    //The render pass creation
    void createRenderPass() {
        //Color Attachment
        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;

        //Color Attachment Ref
        VkAttachmentReference colorAttachmentRef = {};
        colorAttachmentRef.attachment = 0;
        colorAttachmentRef.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

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

        //Subpass Dependency
        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;

        //Render Pass Info
        VkRenderPassCreateInfo renderPassInfo = {};
        renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
        renderPassInfo.attachmentCount = 1;
        renderPassInfo.pAttachments = &colorAttachment;
        renderPassInfo.subpassCount = 1;
        renderPassInfo.pSubpasses = &subpass;
        renderPassInfo.dependencyCount = 1;
        renderPassInfo.pDependencies = &dependency;

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

    //The graphics pipeline creation
    void createGraphicsPipeline() {
        auto vertShaderCode = readFile("shaders/vert.spv");
        auto fragShaderCode = readFile("shaders/frag.spv");
    
        VkShaderModule vertShaderModule = createShaderModule(vertShaderCode);
        VkShaderModule fragShaderModule = createShaderModule(fragShaderCode);

        //Vertex shader info
        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";

        //Fragment shader info
        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";

        //Shader Stage Info
        VkPipelineShaderStageCreateInfo shaderStages[] = { vertShaderStageInfo, fragShaderStageInfo };

        //Vertex Input
        VkPipelineVertexInputStateCreateInfo vertexInputInfo = {};
        vertexInputInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
        vertexInputInfo.vertexBindingDescriptionCount = 0;
        vertexInputInfo.pVertexBindingDescriptions = nullptr;

        //Optional
        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;

        //Viewport
        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;

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

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

        //Rasterizer
        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;

        //Optional
        rasterizer.depthBiasConstantFactor = 0.0f;
        rasterizer.depthBiasClamp = 0.0f;
        rasterizer.depthBiasSlopeFactor = 0.0f;

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

        //Color Blend Attachment
        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;

        //Optional
        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;
        colorBlendAttachment.blendEnable = VK_TRUE;
        colorBlendAttachment.srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
        colorBlendAttachment.dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
        colorBlendAttachment.colorBlendOp = VK_BLEND_OP_ADD;
        colorBlendAttachment.srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE;
        colorBlendAttachment.dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
        colorBlendAttachment.alphaBlendOp = VK_BLEND_OP_ADD;

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

        //Dynamic States
        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;

        //Pipeline Layout Info
        VkPipelineLayoutCreateInfo pipelineLayoutInfo = {};
        pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
        pipelineLayoutInfo.setLayoutCount = 0; // Optional
        pipelineLayoutInfo.pSetLayouts = nullptr; // Optional
        pipelineLayoutInfo.pushConstantRangeCount = 0; // Optional
        pipelineLayoutInfo.pPushConstantRanges = nullptr; // Optional

        if (vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &pipelineLayout) != VK_SUCCESS) {
            std::cout << "failed to create pipeline layout!" << std::endl;
        }
        
        //Pipeline Info
        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;

        //Optional
        pipelineInfo.basePipelineIndex = -1;

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

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

    //Frame buffer Creation
    void createFramebuffers() {
        swapChainFramebuffers.resize(swapChainImageViews.size());

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

            //Frame Buffer Info
            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) {
                std::cout << "failed to create framebuffer!" << std::endl;
            }
        }
    }

    //Command Pool Creation
    void createCommandPool() {
        QueueFamilyIndices queueFamilyIndices = findQueueFamilies(physicalDevice);

        //Command Pool Info
        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) {
            std::cout << "failed to create command pool!" << std::endl;
        }
    }

    //Command Buffer Creation
    void createCommandBuffers() {
        commandBuffers.resize(swapChainFramebuffers.size());

        //Command Buffer Allocation Info
        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) {
            std::cout << "failed to allocate command buffers!" << std::endl;
        }

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

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

            //Render Pass Begin Info
            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;
            
            //Clear Color
            VkClearValue clearColor = {0.0f, 0.0f, 0.0f, 1.0f};
            renderPassInfo.clearValueCount = 1;
            renderPassInfo.pClearValues = &clearColor;

            //Begin Rendering
            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) {
                std::cout << "failed to record command buffers!" << std::endl;
            }
        }
    }

    //Semaphore and Fence Creation
    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) {
                std::cout << "failed to create synchronization objects for a frame!" << std::endl;
            }
        }
    }

    //Draw The Frame
    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) {
            std::cout << "failed to submit draw command buffer!" << std::endl;
        }

        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;
    }

    //Creating Shader Module
    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) {
            std::cout << "Failed to create shader module!" << std::endl;
        }

        return shaderModule;
    }

    VkSurfaceFormatKHR chooseSwapSurfaceFormat(const std::vector<VkSurfaceFormatKHR>& availableFormats) {
        for(const auto& availableFormat : availableFormats) {
            if(availableFormat.format == VK_FORMAT_B8G8R8_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;
        }
    }

    //Query Swapn Chain Support
    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;
    }

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

		bool extensionsSupported = checkDeviceExtensionSupport(device);

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

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

    //Checks device for extension support
	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();
	}

    //Queue Family lookup function
    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;
        //Find atleast one queue family that supports VK_QUEUE_GRAPHICS_BIT
        for(const auto& queueFamily : queueFamilies) {
			if(queueFamily.queueCount > 0 && queueFamily.queueFlags & VK_QUEUE_GRAPHICS_BIT) {
				indices.graphicsFamily = i;
			}

            VkBool32 presentSupport = false;
            vkGetPhysicalDeviceSurfaceSupportKHR(device, i, surface, &presentSupport);

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

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

			i++;
        }
        
        return indices;
    }

    //Get Required Extensions
    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;
    }

    //Checks Validation Support
    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;
            }
        }

        return true;
    }

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

        //check to see if file is open
        if(!file.is_open()) {
            std::cout << "Failed to open file!" << std::endl;
        }

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

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

        file.close();

        return buffer;
    }

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

        return VK_FALSE;
    }

};

int main() {
    HelloTriangleApplication app;

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

    return EXIT_SUCCESS;
}