// Sample by Sascha Willems

// Contact: webmaster@saschawillems.de

#define GLFW_INCLUDE_VULKAN

#include <GLFW/glfw3.h>

#define GLM_FORCE_RADIANS

#include <glm/glm.hpp>

#include <glm/gtc/matrix_transform.hpp>

#include <iostream>

#include <fstream>

#include <stdexcept>

#include <algorithm>

#include <chrono>

#include <vector>

#include <cstring>

#include <cstdlib>

#include <cstdint>

#include <limits>

#include <array>

#include <optional>

#include <set>

#include <random>

const uint32_t WIDTH = 800;

const uint32_t HEIGHT = 600;

const uint32_t PARTICLE_COUNT = 8192;

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

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);

}

}

struct QueueFamilyIndices {

std::optional<uint32_t> graphicsAndComputeFamily;

std::optional<uint32_t> presentFamily;

bool isComplete() {

return graphicsAndComputeFamily.has_value() && presentFamily.has_value();

}

};

struct SwapChainSupportDetails {

VkSurfaceCapabilitiesKHR capabilities;

std::vector<VkSurfaceFormatKHR> formats;

std::vector<VkPresentModeKHR> presentModes;

};

struct UniformBufferObject {

float deltaTime = 1.0f;

};

struct Particle {

glm::vec2 position;

glm::vec2 velocity;

glm::vec4 color;

static VkVertexInputBindingDescription getBindingDescription() {

VkVertexInputBindingDescription bindingDescription{};

bindingDescription.binding = 0;

bindingDescription.stride = sizeof(Particle);

bindingDescription.inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

return bindingDescription;

}

static std::array<VkVertexInputAttributeDescription, 2> getAttributeDescriptions() {

std::array<VkVertexInputAttributeDescription, 2> attributeDescriptions{};

attributeDescriptions[0].binding = 0;

attributeDescriptions[0].location = 0;

attributeDescriptions[0].format = VK_FORMAT_R32G32_SFLOAT;

attributeDescriptions[0].offset = offsetof(Particle, position);

attributeDescriptions[1].binding = 0;

attributeDescriptions[1].location = 1;

attributeDescriptions[1].format = VK_FORMAT_R32G32B32A32_SFLOAT;

attributeDescriptions[1].offset = offsetof(Particle, color);

return attributeDescriptions;

}

};

class ComputeShaderApplication {

public:

void run() {

initWindow();

initVulkan();

mainLoop();

cleanup();

}

private:

GLFWwindow* window;

VkInstance instance;

VkDebugUtilsMessengerEXT debugMessenger;

VkSurfaceKHR surface;

VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;

VkDevice device;

VkQueue graphicsQueue;

VkQueue computeQueue;

VkQueue presentQueue;

VkSwapchainKHR swapChain;

std::vector<VkImage> swapChainImages;

VkFormat swapChainImageFormat;

VkExtent2D swapChainExtent;

std::vector<VkImageView> swapChainImageViews;

std::vector<VkFramebuffer> swapChainFramebuffers;

VkRenderPass renderPass;

VkPipelineLayout pipelineLayout;

VkPipeline graphicsPipeline;

VkDescriptorSetLayout computeDescriptorSetLayout;

VkPipelineLayout computePipelineLayout;

VkPipeline computePipeline;

VkCommandPool commandPool;

std::vector<VkBuffer> shaderStorageBuffers;

std::vector<VkDeviceMemory> shaderStorageBuffersMemory;

std::vector<VkBuffer> uniformBuffers;

std::vector<VkDeviceMemory> uniformBuffersMemory;

std::vector<void*> uniformBuffersMapped;

VkDescriptorPool descriptorPool;

std::vector<VkDescriptorSet> computeDescriptorSets;

std::vector<VkCommandBuffer> commandBuffers;

std::vector<VkCommandBuffer> computeCommandBuffers;

std::vector<VkSemaphore> imageAvailableSemaphores;

std::vector<VkSemaphore> renderFinishedSemaphores;

std::vector<VkSemaphore> computeFinishedSemaphores;

std::vector<VkFence> inFlightFences;

std::vector<VkFence> computeInFlightFences;

uint32_t currentFrame = 0;

float lastFrameTime = 0.0f;

bool framebufferResized = false;

double lastTime = 0.0f;

void initWindow() {

glfwInit();

glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);

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

glfwSetWindowUserPointer(window, this);

glfwSetFramebufferSizeCallback(window, framebufferResizeCallback);

lastTime = glfwGetTime();

}

static void framebufferResizeCallback(GLFWwindow* window, int width, int height) {

auto app = reinterpret_cast<ComputeShaderApplication*>(glfwGetWindowUserPointer(window));

app->framebufferResized = true;

}

void initVulkan() {

createInstance();

setupDebugMessenger();

createSurface();

pickPhysicalDevice();

createLogicalDevice();

createSwapChain();

createImageViews();

createRenderPass();

createComputeDescriptorSetLayout();

createGraphicsPipeline();

createComputePipeline();

createFramebuffers();

createCommandPool();

createShaderStorageBuffers();

createUniformBuffers();

createDescriptorPool();

createComputeDescriptorSets();

createCommandBuffers();

createComputeCommandBuffers();

createSyncObjects();

}

void mainLoop() {

while (!glfwWindowShouldClose(window)) {

glfwPollEvents();

drawFrame();

// We want to animate the particle system using the last frames time to get smooth, frame-rate independent animation

double currentTime = glfwGetTime();

lastFrameTime = (currentTime - lastTime) * 1000.0;

lastTime = currentTime;

}

vkDeviceWaitIdle(device);

}

void cleanupSwapChain() {

for (auto framebuffer : swapChainFramebuffers) {

vkDestroyFramebuffer(device, framebuffer, nullptr);

}

for (auto imageView : swapChainImageViews) {

vkDestroyImageView(device, imageView, nullptr);

}

vkDestroySwapchainKHR(device, swapChain, nullptr);

}

void cleanup() {

cleanupSwapChain();

vkDestroyPipeline(device, graphicsPipeline, nullptr);

vkDestroyPipelineLayout(device, pipelineLayout, nullptr);

vkDestroyPipeline(device, computePipeline, nullptr);

vkDestroyPipelineLayout(device, computePipelineLayout, nullptr);

vkDestroyRenderPass(device, renderPass, nullptr);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {

vkDestroyBuffer(device, uniformBuffers[i], nullptr);

vkFreeMemory(device, uniformBuffersMemory[i], nullptr);

}

vkDestroyDescriptorPool(device, descriptorPool, nullptr);

vkDestroyDescriptorSetLayout(device, computeDescriptorSetLayout, nullptr);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {

vkDestroyBuffer(device, shaderStorageBuffers[i], nullptr);

vkFreeMemory(device, shaderStorageBuffersMemory[i], nullptr);

}

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {

vkDestroySemaphore(device, renderFinishedSemaphores[i], nullptr);

vkDestroySemaphore(device, imageAvailableSemaphores[i], nullptr);

vkDestroySemaphore(device, computeFinishedSemaphores[i], nullptr);

vkDestroyFence(device, inFlightFences[i], nullptr);

vkDestroyFence(device, computeInFlightFences[i], nullptr);

}

vkDestroyCommandPool(device, commandPool, nullptr);

vkDestroyDevice(device, nullptr);

if (enableValidationLayers) {

DestroyDebugUtilsMessengerEXT(instance, debugMessenger, nullptr);

}

vkDestroySurfaceKHR(instance, surface, nullptr);

vkDestroyInstance(instance, nullptr);

glfwDestroyWindow(window);

glfwTerminate();

}

void recreateSwapChain() {

int width = 0, height = 0;

glfwGetFramebufferSize(window, &width, &height);

while (width == 0 || height == 0) {

glfwGetFramebufferSize(window, &width, &height);

glfwWaitEvents();

}

vkDeviceWaitIdle(device);

cleanupSwapChain();

createSwapChain();

createImageViews();

createFramebuffers();

}

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;

}

if (vkCreateInstance(&createInfo, nullptr, &instance) != VK_SUCCESS) {

throw std::runtime_error("failed to create instance!");

}

}

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 createSurface() {

if (glfwCreateWindowSurface(instance, window, nullptr, &surface) != VK_SUCCESS) {

throw std::runtime_error("failed to create window surface!");

}

}

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 createLogicalDevice() {

QueueFamilyIndices indices = findQueueFamilies(physicalDevice);

std::vector<VkDeviceQueueCreateInfo> queueCreateInfos;

std::set<uint32_t> uniqueQueueFamilies = {indices.graphicsAndComputeFamily.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.graphicsAndComputeFamily.value(), 0, &graphicsQueue);

vkGetDeviceQueue(device, indices.graphicsAndComputeFamily.value(), 0, &computeQueue);

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.graphicsAndComputeFamily.value(), indices.presentFamily.value()};

if (indices.graphicsAndComputeFamily != 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;

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!");

}

}

}

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;

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_WRITE_BIT;

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) {

throw std::runtime_error("failed to create render pass!");

}

}

void createComputeDescriptorSetLayout() {

std::array<VkDescriptorSetLayoutBinding, 3> layoutBindings{};

layoutBindings[0].binding = 0;

layoutBindings[0].descriptorCount = 1;

layoutBindings[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;

layoutBindings[0].pImmutableSamplers = nullptr;

layoutBindings[0].stageFlags = VK_SHADER_STAGE_COMPUTE_BIT;

layoutBindings[1].binding = 1;

layoutBindings[1].descriptorCount = 1;

layoutBindings[1].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;

layoutBindings[1].pImmutableSamplers = nullptr;

layoutBindings[1].stageFlags = VK_SHADER_STAGE_COMPUTE_BIT;

layoutBindings[2].binding = 2;

layoutBindings[2].descriptorCount = 1;

layoutBindings[2].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;

layoutBindings[2].pImmutableSamplers = nullptr;

layoutBindings[2].stageFlags = VK_SHADER_STAGE_COMPUTE_BIT;

VkDescriptorSetLayoutCreateInfo layoutInfo{};

layoutInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;

layoutInfo.bindingCount = 3;

layoutInfo.pBindings = layoutBindings.data();

if (vkCreateDescriptorSetLayout(device, &layoutInfo, nullptr, &computeDescriptorSetLayout) != VK_SUCCESS) {

throw std::runtime_error("failed to create compute descriptor set layout!");

}

}

void createGraphicsPipeline() {

auto vertShaderCode = readFile("shaders/vert.spv");

auto fragShaderCode = readFile("shaders/frag.spv");

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;

auto bindingDescription = Particle::getBindingDescription();

auto attributeDescriptions = Particle::getAttributeDescriptions();

vertexInputInfo.vertexBindingDescriptionCount = 1;

vertexInputInfo.vertexAttributeDescriptionCount = static_cast<uint32_t>(attributeDescriptions.size());

vertexInputInfo.pVertexBindingDescriptions = &bindingDescription;

vertexInputInfo.pVertexAttributeDescriptions = attributeDescriptions.data();

VkPipelineInputAssemblyStateCreateInfo inputAssembly{};

inputAssembly.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;

inputAssembly.topology = VK_PRIMITIVE_TOPOLOGY_POINT_LIST;

inputAssembly.primitiveRestartEnable = VK_FALSE;

VkPipelineViewportStateCreateInfo viewportState{};

viewportState.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;

viewportState.viewportCount = 1;

viewportState.scissorCount = 1;

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_COUNTER_CLOCKWISE;

rasterizer.depthBiasEnable = VK_FALSE;

VkPipelineMultisampleStateCreateInfo multisampling{};

multisampling.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;

multisampling.sampleShadingEnable = VK_FALSE;

multisampling.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;

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_TRUE;

colorBlendAttachment.colorBlendOp = VK_BLEND_OP_ADD;

colorBlendAttachment.srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;

colorBlendAttachment.dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;

colorBlendAttachment.alphaBlendOp = VK_BLEND_OP_ADD;

colorBlendAttachment.srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;

colorBlendAttachment.dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;

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;

std::vector<VkDynamicState> dynamicStates = {

VK_DYNAMIC_STATE_VIEWPORT,

VK_DYNAMIC_STATE_SCISSOR

};

VkPipelineDynamicStateCreateInfo dynamicState{};

dynamicState.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;

dynamicState.dynamicStateCount = static_cast<uint32_t>(dynamicStates.size());

dynamicState.pDynamicStates = dynamicStates.data();

VkPipelineLayoutCreateInfo pipelineLayoutInfo{};

pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;

pipelineLayoutInfo.setLayoutCount = 0;

pipelineLayoutInfo.pSetLayouts = 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.pColorBlendState = &colorBlending;

pipelineInfo.pDynamicState = &dynamicState;

pipelineInfo.layout = pipelineLayout;

pipelineInfo.renderPass = renderPass;

pipelineInfo.subpass = 0;

pipelineInfo.basePipelineHandle = VK_NULL_HANDLE;

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 createComputePipeline() {

auto computeShaderCode = readFile("shaders/comp.spv");

VkShaderModule computeShaderModule = createShaderModule(computeShaderCode);

VkPipelineShaderStageCreateInfo computeShaderStageInfo{};

computeShaderStageInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;

computeShaderStageInfo.stage = VK_SHADER_STAGE_COMPUTE_BIT;

computeShaderStageInfo.module = computeShaderModule;

computeShaderStageInfo.pName = "main";

VkPipelineLayoutCreateInfo pipelineLayoutInfo{};

pipelineLayoutInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;

pipelineLayoutInfo.setLayoutCount = 1;

pipelineLayoutInfo.pSetLayouts = &computeDescriptorSetLayout;

if (vkCreatePipelineLayout(device, &pipelineLayoutInfo, nullptr, &computePipelineLayout) != VK_SUCCESS) {

throw std::runtime_error("failed to create compute pipeline layout!");

}

VkComputePipelineCreateInfo pipelineInfo{};

pipelineInfo.sType = VK_STRUCTURE_TYPE_COMPUTE_PIPELINE_CREATE_INFO;

pipelineInfo.layout = computePipelineLayout;

pipelineInfo.stage = computeShaderStageInfo;

if (vkCreateComputePipelines(device, VK_NULL_HANDLE, 1, &pipelineInfo, nullptr, &computePipeline) != VK_SUCCESS) {

throw std::runtime_error("failed to create compute pipeline!");

}

vkDestroyShaderModule(device, computeShaderModule, 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.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;

poolInfo.queueFamilyIndex = queueFamilyIndices.graphicsAndComputeFamily.value();

if (vkCreateCommandPool(device, &poolInfo, nullptr, &commandPool) != VK_SUCCESS) {

throw std::runtime_error("failed to create graphics command pool!");

}

}

void createShaderStorageBuffers() {

// Initialize particles

std::default_random_engine rndEngine((unsigned)time(nullptr));

std::uniform_real_distribution<float> rndDist(0.0f, 1.0f);

// Initial particle positions on a circle

std::vector<Particle> particles(PARTICLE_COUNT);

for (auto& particle : particles) {

float r = 0.25f * sqrt(rndDist(rndEngine));

float theta = rndDist(rndEngine) * 2.0f * 3.14159265358979323846f;

float x = r * cos(theta) * HEIGHT / WIDTH;

float y = r * sin(theta);

particle.position = glm::vec2(x, y);

particle.velocity = glm::normalize(glm::vec2(x,y)) * 0.00025f;

particle.color = glm::vec4(rndDist(rndEngine), rndDist(rndEngine), rndDist(rndEngine), 1.0f);

}

VkDeviceSize bufferSize = sizeof(Particle) * PARTICLE_COUNT;

// Create a staging buffer used to upload data to the gpu

VkBuffer stagingBuffer;

VkDeviceMemory stagingBufferMemory;

createBuffer(bufferSize, VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, stagingBuffer, stagingBufferMemory);

void* data;

vkMapMemory(device, stagingBufferMemory, 0, bufferSize, 0, &data);

memcpy(data, particles.data(), (size_t)bufferSize);

vkUnmapMemory(device, stagingBufferMemory);

shaderStorageBuffers.resize(MAX_FRAMES_IN_FLIGHT);

shaderStorageBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);

// Copy initial particle data to all storage buffers

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {

createBuffer(bufferSize, VK_BUFFER_USAGE_STORAGE_BUFFER_BIT | VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, shaderStorageBuffers[i], shaderStorageBuffersMemory[i]);

copyBuffer(stagingBuffer, shaderStorageBuffers[i], bufferSize);

}

vkDestroyBuffer(device, stagingBuffer, nullptr);

vkFreeMemory(device, stagingBufferMemory, nullptr);

}

void createUniformBuffers() {

VkDeviceSize bufferSize = sizeof(UniformBufferObject);

uniformBuffers.resize(MAX_FRAMES_IN_FLIGHT);

uniformBuffersMemory.resize(MAX_FRAMES_IN_FLIGHT);

uniformBuffersMapped.resize(MAX_FRAMES_IN_FLIGHT);

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {

createBuffer(bufferSize, VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, uniformBuffers[i], uniformBuffersMemory[i]);

vkMapMemory(device, uniformBuffersMemory[i], 0, bufferSize, 0, &uniformBuffersMapped[i]);

}

}

void createDescriptorPool() {

std::array<VkDescriptorPoolSize, 2> poolSizes{};

poolSizes[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;

poolSizes[0].descriptorCount = static_cast<uint32_t>(MAX_FRAMES_IN_FLIGHT);

poolSizes[1].type = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;

poolSizes[1].descriptorCount = static_cast<uint32_t>(MAX_FRAMES_IN_FLIGHT) * 2;

VkDescriptorPoolCreateInfo poolInfo{};

poolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;

poolInfo.poolSizeCount = 2;

poolInfo.pPoolSizes = poolSizes.data();

poolInfo.maxSets = static_cast<uint32_t>(MAX_FRAMES_IN_FLIGHT);

if (vkCreateDescriptorPool(device, &poolInfo, nullptr, &descriptorPool) != VK_SUCCESS) {

throw std::runtime_error("failed to create descriptor pool!");

}

}

void createComputeDescriptorSets() {

std::vector<VkDescriptorSetLayout> layouts(MAX_FRAMES_IN_FLIGHT, computeDescriptorSetLayout);

VkDescriptorSetAllocateInfo allocInfo{};

allocInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;

allocInfo.descriptorPool = descriptorPool;

allocInfo.descriptorSetCount = static_cast<uint32_t>(MAX_FRAMES_IN_FLIGHT);

allocInfo.pSetLayouts = layouts.data();

computeDescriptorSets.resize(MAX_FRAMES_IN_FLIGHT);

if (vkAllocateDescriptorSets(device, &allocInfo, computeDescriptorSets.data()) != VK_SUCCESS) {

throw std::runtime_error("failed to allocate descriptor sets!");

}

for (size_t i = 0; i < MAX_FRAMES_IN_FLIGHT; i++) {

VkDescriptorBufferInfo uniformBufferInfo{};

uniformBufferInfo.buffer = uniformBuffers[i];

uniformBufferInfo.offset = 0;

uniformBufferInfo.range = sizeof(UniformBufferObject);

std::array<VkWriteDescriptorSet, 3> descriptorWrites{};

descriptorWrites[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;

descriptorWrites[0].dstSet = computeDescriptorSets[i];

descriptorWrites[0].dstBinding = 0;

descriptorWrites[0].dstArrayElement = 0;

descriptorWrites[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;

descriptorWrites[0].descriptorCount = 1;

descriptorWrites[0].pBufferInfo = &uniformBufferInfo;

VkDescriptorBufferInfo storageBufferInfoLastFrame{};

storageBufferInfoLastFrame.buffer = shaderStorageBuffers[(i - 1) % MAX_FRAMES_IN_FLIGHT];

storageBufferInfoLastFrame.offset = 0;

storageBufferInfoLastFrame.range = sizeof(Particle) * PARTICLE_COUNT;

descriptorWrites[1].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;

descriptorWrites[1].dstSet = computeDescriptorSets[i];

descriptorWrites[1].dstBinding = 1;

descriptorWrites[1].dstArrayElement = 0;

descriptorWrites[1].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;

descriptorWrites[1].descriptorCount = 1;

descriptorWrites[1].pBufferInfo = &storageBufferInfoLastFrame;

VkDescriptorBufferInfo storageBufferInfoCurrentFrame{};

storageBufferInfoCurrentFrame.buffer = shaderStorageBuffers[i];

storageBufferInfoCurrentFrame.offset = 0;

storageBufferInfoCurrentFrame.range = sizeof(Particle) * PARTICLE_COUNT;

descriptorWrites[2].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;

descriptorWrites[2].dstSet = computeDescriptorSets[i];

descriptorWrites[2].dstBinding = 2;

descriptorWrites[2].dstArrayElement = 0;

descriptorWrites[2].descriptorType = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER;

descriptorWrites[2].descriptorCount = 1;

descriptorWrites[2].pBufferInfo = &storageBufferInfoCurrentFrame;

vkUpdateDescriptorSets(device, 3, descriptorWrites.data(), 0, nullptr);

}

}

void createBuffer(VkDeviceSize size, VkBufferUsageFlags usage, VkMemoryPropertyFlags properties, VkBuffer& buffer, VkDeviceMemory& bufferMemory) {

VkBufferCreateInfo bufferInfo{};

bufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;

bufferInfo.size = size;

bufferInfo.usage = usage;

bufferInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;

if (vkCreateBuffer(device, &bufferInfo, nullptr, &buffer) != VK_SUCCESS) {

throw std::runtime_error("failed to create buffer!");

}

VkMemoryRequirements memRequirements;

vkGetBufferMemoryRequirements(device, buffer, &memRequirements);

VkMemoryAllocateInfo allocInfo{};

allocInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;

allocInfo.allocationSize = memRequirements.size;

allocInfo.memoryTypeIndex = findMemoryType(memRequirements.memoryTypeBits, properties);

if (vkAllocateMemory(device, &allocInfo, nullptr, &bufferMemory) != VK_SUCCESS) {

throw std::runtime_error("failed to allocate buffer memory!");

}

vkBindBufferMemory(device, buffer, bufferMemory, 0);

}

void copyBuffer(VkBuffer srcBuffer, VkBuffer dstBuffer, VkDeviceSize size) {

VkCommandBufferAllocateInfo allocInfo{};

allocInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;

allocInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;

allocInfo.commandPool = commandPool;

allocInfo.commandBufferCount = 1;

VkCommandBuffer commandBuffer;

vkAllocateCommandBuffers(device, &allocInfo, &commandBuffer);

VkCommandBufferBeginInfo beginInfo{};

beginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;

beginInfo.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;

vkBeginCommandBuffer(commandBuffer, &beginInfo);

VkBufferCopy copyRegion{};

copyRegion.size = size;

vkCmdCopyBuffer(commandBuffer, srcBuffer, dstBuffer, 1, &copyRegion);

vkEndCommandBuffer(commandBuffer);

VkSubmitInfo submitInfo{};

submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;

submitInfo.commandBufferCount = 1;

submitInfo.pCommandBuffers = &commandBuffer;

vkQueueSubmit(graphicsQueue, 1, &submitInfo, VK_NULL_HANDLE);

vkQueueWaitIdle(graphicsQueue);

vkFreeCommandBuffers(device, commandPool, 1, &commandBuffer);

}

uint32_t findMemoryType(uint32_t typeFilter, VkMemoryPropertyFlags properties) {

VkPhysicalDeviceMemoryProperties memProperties;

vkGetPhysicalDeviceMemoryProperties(physicalDevice, &memProperties);

for (uint32_t i = 0; i < memProperties.memoryTypeCount; i++) {

if ((typeFilter & (1 << i)) && (memProperties.memoryTypes[i].propertyFlags & properties) == properties) {

return i;

}

}

throw std::runtime_error("failed to find suitable memory type!");

}

void createCommandBuffers() {

commandBuffers.resize(MAX_FRAMES_IN_FLIGHT);

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!");

}

}