（六）窗口表面

这节主要三部分
一，窗口表面的创建和销毁
二，呈现队列
三，与以前实现的图形能力队列的兼容

一，窗口表面
1，创建
VkSurfaceKHR surface;

//创建窗口表面
glfwCreateWindowSurface(
	instance,	//vkInstance对象
	window,		//GLFW窗口指针
	nullptr,	//自定义内存分配器
	&surface);	//存储返回的表面的内存地址

2，销毁

vkDestroySurfaceKHR(instance, surface, nullptr);

二，呈现队列：将图像呈现到窗口表面，也是种能力，所以要有这个队列。

1，结构体

//队列族索引,同时支持绘制指令的队列族和支持表现的队列族
struct QueueFaminliyIndices
{
//-1表示没找到满足需求的队列族
int graphicsFamily = -1;
int presentFamily = -1;
bool isCompleted()
{
return graphicsFamily >= 0 && presentFamily >= 0;
}
};

2，检查是否支持

	VkBool32 presentSupport = false;
	vkGetPhysicalDeviceSurfaceSupportKHR(device, i, surface, &presentSupport);
	if (queueFamily.queueCount > 0 && presentSupport)
	{
		indices.presentFamily = i;
	}

3，获取队列句柄
//呈现队列
VkQueue presentQueue;
vkGetDeviceQueue(device, indices.presentFamily, 0, &presentQueue);

三，与以前实现的图形能力队列的兼容

std::set<int> uniqueQueueFamilies = { indices.graphicsFamily, indices.presentFamily };

std::vector<VkDeviceQueueCreateInfo> queueCreateInfos;
float queuePriority = 1.0f;

//遍历各个队列族，
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);
}
createInfo.pQueueCreateInfos = queueCreateInfos.data();
createInfo.queueCreateInfoCount = static_cast<uint32_t> (queueCreateInfos.size());

运行

完整代码如下：
MyApplication.h
#pragma once
#include <Windows.h>
#include <glm/vec4.hpp>
#include <glm/mat4x4.hpp>
#include <vulkan/vulkan.h>
#include <vulkan/vulkan_win32.h>
#include
#include “D:/install/filament-v1.18.0/third_party/imgui/examples/libs/glfw/include/GLFW/glfw3.h”
#include
#include
#include
#include
#include

//队列族索引,同时支持绘制指令的队列族和支持表现的队列族
struct QueueFaminliyIndices
{
//-1表示没找到满足需求的队列族
int graphicsFamily = -1;
int presentFamily = -1;
bool isCompleted()
{
return graphicsFamily >= 0 && presentFamily >= 0;
}
};
class MyApplication
{
public:
void run();

private:
//初始化窗口
void initWindow();
//初始化Vulkan对象
void initVulkan();
//主循环进行渲染操作
void mainLoop();
//资源清理
void cleanUp();

//创建一个实例初始化Vulkan库,指定驱动程序需要使用的应用程序信息
void createInstance();
//查询显卡设备
void pickPhysicalDevice();

//返回查找的队列族索引
QueueFaminliyIndices findQueueFamilies(VkPhysicalDevice device);
//确保选择的设备能执行需要的指令
bool isDeviceSuitable(VkPhysicalDevice device);
//创建逻辑设备
void createLogicalDevice();
//创建表面
void createSurface();

private:
//窗口
GLFWwindow* window = nullptr;

//实例句柄
VkInstance instance;
//存储显卡信息
VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
//逻辑设备
VkDevice device;
//存储逻辑设备的队列句柄
VkQueue graphicsQueue;

//窗口表面
VkSurfaceKHR surface;
//呈现队列
VkQueue presentQueue;

};
MyApplication.cpp
#include “MyApplication.h”

void MyApplication::run()
{
initWindow();
initVulkan();
mainLoop();
cleanUp();
}

void MyApplication::initWindow()
{

//初始化GLFW库，
glfwInit();
//阻止创建OpenGL上下文
glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
//禁止窗口大小改变
glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
//存储窗口句柄
const int WIDTH = 800;
const int HEIGHT = 600;
window = glfwCreateWindow(WIDTH, HEIGHT, "Vulkan window", nullptr, nullptr);

}

void MyApplication::initVulkan()
{
createInstance();
createSurface();
pickPhysicalDevice();
createLogicalDevice();
}

void MyApplication::mainLoop()
{
//在没有错误和窗口没有被关闭下一直运行，事件循环
while (!glfwWindowShouldClose(window))
{
glfwPollEvents();
}
}

void MyApplication::cleanUp()
{
vkDestroyDevice(device, nullptr);
vkDestroySurfaceKHR(instance, surface, nullptr);
vkDestroyInstance(instance, nullptr);
glfwDestroyWindow(window);
glfwTerminate();
}

void MyApplication::createInstance()
{
//应用程序信息,便于优化
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;

//创建Vulkan驱动程序需要的信息
VkInstanceCreateInfo createInfo = {};
createInfo.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
createInfo.pApplicationInfo = &appInfo;

//返回需要的窗口交互扩展
uint32_t glfwExtensionCount = 0;
const char** glfwExtensions = glfwGetRequiredInstanceExtensions(&glfwExtensionCount);
createInfo.enabledExtensionCount = glfwExtensionCount;
createInfo.ppEnabledExtensionNames = glfwExtensions;

//全局扩展层（对整个应用程序都有效，而不仅仅对一个设备有效）
//暂时设置为0，不使用全局扩展层
createInfo.enabledLayerCount = 0;

//创建Vulkan实例
VkResult result = vkCreateInstance(
	&createInfo,	//包含创建信息的结构体指针
	nullptr,		//自定义的分配器回调函数，暂时设置为nullptr,不使用
	&instance);		//指向新对象句柄存储位置的指针。

//检测扩展支持
//获取扩展数量
uint32_t extensionCount = 0;
vkEnumerateInstanceExtensionProperties(nullptr, &extensionCount, nullptr);
//存储信息数组
std::vector<VkExtensionProperties> extensions(extensionCount);

vkEnumerateInstanceExtensionProperties(nullptr, &extensionCount, extensions.data());

}

void MyApplication::pickPhysicalDevice()
{
//获取显卡设备数量
uint32_t deviceCount = 0;
vkEnumeratePhysicalDevices(instance, &deviceCount, nullptr);

//获取显卡数组
std::vector<VkPhysicalDevice> devices(deviceCount);
vkEnumeratePhysicalDevices(instance, &deviceCount, devices.data());

//选择合适的
for (const auto& device : devices)
{
	if (isDeviceSuitable(device))
	{
		physicalDevice = device;
		break;
	}
}

}

QueueFaminliyIndices MyApplication::findQueueFamilies(VkPhysicalDevice device)
{
//获取设备的队列族个数
uint32_t queueFamilyCount = 0;
vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, nullptr);
//获取队列族数组
std::vector queueFamilies(queueFamilyCount);
vkGetPhysicalDeviceQueueFamilyProperties(device, &queueFamilyCount, queueFamilies.data());

QueueFaminliyIndices indices;
//支持
//1,图形指令
//2,呈现图像到窗口表面能力
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 (queueFamily.queueCount > 0 && presentSupport)
	{
		indices.presentFamily = i;
	}
	if (indices.isCompleted())
	{
		break;
	}
	i++;
}
return indices;

}

bool MyApplication::isDeviceSuitable(VkPhysicalDevice device)
{
QueueFaminliyIndices indices = findQueueFamilies(device);
return indices.isCompleted();
}

void MyApplication::createLogicalDevice()
{
//同时图形能力和呈现到表面能力
QueueFaminliyIndices indices = findQueueFamilies(physicalDevice);
std::set uniqueQueueFamilies = { indices.graphicsFamily, indices.presentFamily };

std::vector<VkDeviceQueueCreateInfo> queueCreateInfos;
float queuePriority = 1.0f;

//遍历各个队列族，
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);
}
//应用的设备特性
VkPhysicalDeviceFeatures deviceFeatures = {};

//创建逻辑设备
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 = 0;

//暂时不用校验层
createInfo.enabledLayerCount = 0;
vkCreateDevice(physicalDevice, &createInfo, nullptr, &device);

//获取队列族的队列句柄
vkGetDeviceQueue(device, indices.graphicsFamily, 0, &graphicsQueue);
vkGetDeviceQueue(device, indices.presentFamily, 0, &presentQueue);

}

void MyApplication::createSurface()
{
//创建窗口表面
glfwCreateWindowSurface(
instance, //vkInstance对象
window, //GLFW窗口指针
nullptr, //自定义内存分配器
&surface); //存储返回的表面的内存地址

}

调用
main.cpp
#define GLFW_INCLUDE_VULKAN
#define GLM_FORCE_RADIANS
#define GLM_FORCE_DEPTH_ZERO_TO_ONE
#include “MyApplication.h”

int main()
{
MyApplication app;
app.run();
return 0;
}