Vulkan 图像与视图
Vulkan 图像与视图,使用任何的VkImage,包括在交换链或者渲染管线中的,我们都需要创建VkImageView对象。从字面上理解它就是一个针对图像的视图或容器,通过它具体的渲染管线才能够读写渲染数据,换句话说VkImage不能与渲染管线进行交互。除此之外,图像视图可以进一步定义具体Image的格式,比如定义为2D贴图,那么本质上就不需要任何级别的mipmapping。
在本章节我们会新增一个createImageViews函数,为每一个交换链中的图像创建基本的视图,这些视图在后面的内容中会被作为颜色目标与渲染管线配合使用。
首先添加一个类成员用于保存图像视图的句柄集:
std::vector<VkImageView> swapChainImageViews;
创建createImagesViews函数,并在创建交换链完成之后调用:
void initVulkan() {
createInstance();
setupDebugCallback();
createSurface();
pickPhysicalDevice();
createLogicalDevice();
createSwapChain();
createImageViews();
}
void createImageViews() {
}
我们需要做的第一件事情需要定义保存图像视图集合的大小:
void createImageViews() {
swapChainImageViews.resize(swapChainImages.size());
}
下一步,循环迭代所有的交换链图像。
for (size_t i = 0; i < swapChainImages.size(); i++) {
}
创建图像视图的参数被定义在VkImageViewCreateInfo结构体中。前几个参数的填充非常简单、直接。
VkImageViewCreateInfo createInfo = {};
createInfo.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
createInfo.image = swapChainImages[i];
其中viewType和format字段用于描述图像数据该被如何解释。viewType参数允许将图像定义为1D textures, 2D textures,3D textures 和cube maps。
createInfo.viewType = VK_IMAGE_VIEW_TYPE_2D;
createInfo.format = swapChainImageFormat;
components字段允许调整颜色通道的最终的映射逻辑。比如,我们可以将所有颜色通道映射为红色通道,以实现单色纹理。我们也可以将通道映射具体的常量数值0和1。在章节中我们使用默认的映射策略。
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;
subresourceRangle字段用于描述图像的使用目标是什么,以及可以被访问的有效区域。我们的图像将会作为color targets,没有任何mipmapping levels 或是多层 multiple layers。
createInfo.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
createInfo.subresourceRange.baseMipLevel = 0;
createInfo.subresourceRange.levelCount = 1;
createInfo.subresourceRange.baseArrayLayer = 0;
createInfo.subresourceRange.layerCount = 1;
如果在编写沉浸式的3D应用程序,比如VR,就需要创建支持多层的交换链。并且通过不同的层为每一个图像创建多个视图,以满足不同层的图像在左右眼渲染时对视图的需要。
创建图像视图调用vkCreateImageView函数:
if (vkCreateImageView(device, &createInfo, nullptr, &swapChainImageViews[i]) != VK_SUCCESS) {
throw std::runtime_error("failed to create image views!");
}
与图像不同的是,图像视图需要明确的创建过程,所以在程序退出的时候,我们需要添加一个循环去销毁他们。
void cleanup() {
for (size_t i = 0; i < swapChainImageViews.size(); i++) {
vkDestroyImageView(device, swapChainImageViews[i], nullptr);
}
...
}
拥有了图像视图后,使用图像作为贴图已经足够了,但是它还没有准备好作为渲染的 target 。它需要更多的间接步骤去准备,其中一个就是 framebuffer,被称作帧缓冲区。但首先我们要设置图形管线。
附:全部源码
//ImageView.cpp
// swapChain.cpp
#define GLFW_INCLUDE_VULKAN
#include <GLFW/glfw3.h>
#include <iostream>
#include <stdexcept>
#include <vector>
#include <cstring>
#include <cstdlib>
#include <optional>
#include <set>
#include <algorithm>
const int WIDTH = 800;
const int HEIGHT = 600;
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 {
uint32_t graphicsFamily = -1;
uint32_t presentFamily = -1;
bool isComplete() {
return graphicsFamily >= 0 && presentFamily >= 0;
}
};
struct SwapChainSupportDetails {
VkSurfaceCapabilitiesKHR capabilities;
std::vector<VkSurfaceFormatKHR> formats;
std::vector<VkPresentModeKHR> presentModes;
};
class HelloTriangleApplication {
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 presentQueue;
VkSwapchainKHR swapChain;
std::vector<VkImage> swapChainImages;
VkFormat swapChainImageFormat;
VkExtent2D swapChainExtent;
std::vector<VkImageView> swapChainImageViews;
void initWindow() {
glfwInit();
glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
window = glfwCreateWindow(WIDTH, HEIGHT, "Vulkan", nullptr, nullptr);
}
void initVulkan() {
createInstance();
setupDebugMessenger();
createSurface();
pickPhysicalDevice();
createLogicalDevice();
createSwapChain();
createImageViews();
}
void mainLoop() {
while (!glfwWindowShouldClose(window)) {
glfwPollEvents();
}
}
void cleanup() {
for (size_t i = 0; i < swapChainImageViews.size(); i++) {
vkDestroyImageView(device, swapChainImageViews[i], nullptr);
}
vkDestroySwapchainKHR(device, swapChain, nullptr);
vkDestroyDevice(device, nullptr);
if (enableValidationLayers) {
DestroyDebugUtilsMessengerEXT(instance, debugMessenger, nullptr);
}
vkDestroySurfaceKHR(instance, surface, nullptr);
vkDestroyInstance(instance, nullptr);
glfwDestroyWindow(window);
glfwTerminate();
}
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 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 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.graphicsFamily, indices.presentFamily };
float queuePriority = 1.0f;
for (int 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.pQueueCreateInfos = queueCreateInfos.data();
createInfo.queueCreateInfoCount = static_cast<uint32_t>(queueCreateInfos.size());
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, 0, &graphicsQueue);
vkGetDeviceQueue(device, indices.presentFamily, 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[] = { (uint32_t)indices.graphicsFamily, (uint32_t)indices.presentFamily };
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; // Optional
createInfo.pQueueFamilyIndices = nullptr; // Optional
}
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;
}
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();
}
VkExtent2D chooseSwapExtent(const VkSurfaceCapabilitiesKHR& capabilities) {
if (capabilities.currentExtent.width != std::numeric_limits<uint32_t>::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;
}
}
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) {
if (availableFormats.size() == 1 && availableFormats[0].format == VK_FORMAT_UNDEFINED) {
return { VK_FORMAT_B8G8R8A8_UNORM, VK_COLOR_SPACE_SRGB_NONLINEAR_KHR };
}
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) {
VkPresentModeKHR bestMode = VK_PRESENT_MODE_FIFO_KHR;
for (const auto& availablePresentMode : availablePresentModes) {
if (availablePresentMode == VK_PRESENT_MODE_MAILBOX_KHR) {
return availablePresentMode;
}
else if (availablePresentMode == VK_PRESENT_MODE_IMMEDIATE_KHR) {
bestMode = availablePresentMode;
}
}
return bestMode;
}
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) {
if (queueFamily.queueCount > 0 && queueFamily.queueFlags & VK_QUEUE_GRAPHICS_BIT) {
indices.graphicsFamily = i;
}
VkBool32 presentSupport = false;
vkGetPhysicalDeviceSurfaceSupportKHR(device, i, surface, &presentSupport);
if (presentSupport) {
indices.presentFamily = i;
}
if (indices.isComplete()) {
break;
}
i++;
}
return indices;
}
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;
}
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;
}
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;
}