跟着cherno手搓游戏引擎【4】窗口抽象、GLFW配置、窗口事件

发布于：2024-01-16 ⋅ 阅读:(58) ⋅ 点赞:(0)

引入GLFW：

在vendor里创建GLFW文件夹：

在github上下载，把包下载到GLFW包下。

GitHub - TheCherno/glfw: A multi-platform library for OpenGL, OpenGL ES, Vulkan, window and input修改SRC/premake5.lua的配置：12、13、15、36、37、38、39、40行的代码是新加上去的：

workspace "YOTOEngine"		-- sln文件名
	architecture "x64"	
	configurations{
		"Debug",
		"Release",
		"Dist"
	}
-- https://github.com/premake/premake-core/wiki/Tokens#value-tokens
-- 组成输出目录:Debug-windows-x86_64
outputdir = "%{cfg.buildcfg}-%{cfg.system}-%{cfg.architecture}"

IncludeDir={}
IncludeDir["GLFW"]="YOTOEngine/vendor/GLFW/include"

include "YOTOEngine/vendor/GLFW"

project "YOTOEngine"		--Hazel项目
	location "YOTOEngine"--在sln所属文件夹下的Hazel文件夹
	kind "SharedLib"--dll动态库
	language "C++"
	targetdir ("bin/" .. outputdir .. "/%{prj.name}") -- 输出目录
	objdir ("bin-int/" .. outputdir .. "/%{prj.name}")-- 中间目录
	pchheader "ytpch.h"
	pchsource "YOTOEngine/src/ytpch.cpp"
	-- 包含的所有h和cpp文件
	files{
		"%{prj.name}/src/**.h",
		"%{prj.name}/src/**.cpp"
	}
	-- 包含目录
	includedirs{
		"%{prj.name}/src",
		"%{prj.name}/vendor/spdlog-1.x/include",
		"%{IncludeDir.GLFW}"
	}
	links{
		"GLFW",
		"opengl32.lib"
	}
	-- 如果是window系统
	filter "system:windows"
		cppdialect "C++17"
		-- On:代码生成的运行库选项是MTD,静态链接MSVCRT.lib库;
		-- Off:代码生成的运行库选项是MDD,动态链接MSVCRT.dll库;打包后的exe放到另一台电脑上若无这个dll会报错
		staticruntime "On"	
		systemversion "latest"	-- windowSDK版本
		-- 预处理器定义
		defines{
			"YT_PLATFORM_WINDOWS",
			"YT_BUILD_DLL",
			"YT_ENABLE_ASSERTS",
		}
		-- 编译好后移动Hazel.dll文件到Sandbox文件夹下
		postbuildcommands{
			("{COPY} %{cfg.buildtarget.relpath} ../bin/" .. outputdir .. "/Sandbox")
		}
	-- 不同配置下的预定义不同
	filter "configurations:Debug"
		defines "YT_DEBUG"
		symbols "On"

	filter "configurations:Release"
		defines "YT_RELEASE"
		optimize "On"

	filter "configurations:Dist"
		defines "YT_DIST"
		optimize "On"

project "Sandbox"
	location "Sandbox"
	kind "ConsoleApp"
	language "C++"

	targetdir ("bin/" .. outputdir .. "/%{prj.name}")
	objdir ("bin-int/" .. outputdir .. "/%{prj.name}")

	files{
		"%{prj.name}/src/**.h",
		"%{prj.name}/src/**.cpp"
	}
	-- 同样包含spdlog头文件
	includedirs{
		"YOTOEngine/vendor/spdlog-1.x/include",
		"YOTOEngine/src"
	}
	-- 引用hazel
	links{
		"YOTOEngine",
		"GLFW",
		"opengl32.lib"
	}

	filter "system:windows"
		cppdialect "C++17"
		staticruntime "On"
		systemversion "latest"

		defines{
			"YT_PLATFORM_WINDOWS"
		}

	filter "configurations:Debug"
		defines "YT_DEBUG"
		symbols "On"

	filter "configurations:Release"
		defines "YT_RELEASE"
		optimize "On"

	filter "configurations:Dist"
		defines "YT_DIST"
		optimize "On"

GLFW中的premake5.lua： 

project "GLFW"
	kind "StaticLib"
	language "C"
	staticruntime "off"
	warnings "off"

	targetdir ("bin/" .. outputdir .. "/%{prj.name}")
	objdir ("bin-int/" .. outputdir .. "/%{prj.name}")

	files
	{
		"include/GLFW/glfw3.h",
		"include/GLFW/glfw3native.h",
		"src/glfw_config.h",
		"src/context.c",
		"src/init.c",
		"src/input.c",
		"src/monitor.c",

		"src/null_init.c",
		"src/null_joystick.c",
		"src/null_monitor.c",
		"src/null_window.c",

		"src/platform.c",
		"src/vulkan.c",
		"src/window.c",
	}

	filter "system:linux"
		pic "On"

		systemversion "latest"
		
		files
		{
			"src/x11_init.c",
			"src/x11_monitor.c",
			"src/x11_window.c",
			"src/xkb_unicode.c",
			"src/posix_module.c",
			"src/posix_time.c",
			"src/posix_thread.c",
			"src/posix_module.c",
			"src/glx_context.c",
			"src/egl_context.c",
			"src/osmesa_context.c",
			"src/linux_joystick.c"
		}

		defines
		{
			"_GLFW_X11"
		}

	filter "system:macosx"
		pic "On"

		files
		{
			"src/cocoa_init.m",
			"src/cocoa_monitor.m",
			"src/cocoa_window.m",
			"src/cocoa_joystick.m",
			"src/cocoa_time.c",
			"src/nsgl_context.m",
			"src/posix_thread.c",
			"src/posix_module.c",
			"src/osmesa_context.c",
			"src/egl_context.c"
		}

		defines
		{
			"_GLFW_COCOA"
		}

	filter "system:windows"
		systemversion "latest"

		files
		{
			"src/win32_init.c",
			"src/win32_joystick.c",
			"src/win32_module.c",
			"src/win32_monitor.c",
			"src/win32_time.c",
			"src/win32_thread.c",
			"src/win32_window.c",
			"src/wgl_context.c",
			"src/egl_context.c",
			"src/osmesa_context.c"
		}

		defines 
		{ 
			"_GLFW_WIN32",
			"_CRT_SECURE_NO_WARNINGS"
		}
--解决bug的部分：buildoptions "/MTD" 和"/MT"

	filter "configurations:Debug"
		defines "YT_DEBUG"
		buildoptions "/MTd"
		symbols "On"
	

	filter { "system:windows", "configurations:Debug-AS" }	
		runtime "Debug"
		symbols "on"
		sanitize { "Address" }
		flags { "NoRuntimeChecks", "NoIncrementalLink" }

	filter "configurations:Release"
		defines "YT_RELEASE"
    
		buildoptions "/MT"
		symbols "On"
    
		filter "configurations:Dist"
		defines "YT_DIST"
		buildoptions "/MT"
		symbols "On"

运行测试：

如出现此BUG:请找GLFW中的premake5文件，把上述的premake5.lua的bug解决部分改一下：

使GLFW项目的运行库，只能是MT或者MTD，不能是MD或者MDD

执行GenerateProject.bat文件：

刷新解决方案得到GLFW的包： 

 

窗口抽象： 

创建window基类，用于不同平台window的实现。

YOTO/Window.h：

#pragma once

#include"ytpch.h"
#include"YOTO/Core.h"
#include"YOTO/Event/Event.h"
namespace YOTO {
	struct WindowProps {
		std::string Title;
		unsigned int Width;
		unsigned int Height;
		WindowProps(const std::string &title="YOTO Engine",unsigned int width =1280, unsigned int height = 1280 )
			:Title(title),Width(width),Height(height){}
	};
	class YOTO_API Window {
	public:
		//用EventCallbackFn代替std::function<void(Event&)>：输入为Event&返回值为void 的函数
		using EventCallbackFn = std::function<void(Event&)>;
		virtual ~Window(){}
		//=0为纯虚函数
		virtual void OnUpdate() = 0;
		virtual unsigned int GetWidth() const = 0;
		virtual unsigned int GetHeight() const = 0;
		
		virtual void SetEventCallback(const EventCallbackFn& callback) = 0;
		virtual void SetSync(bool enable)const = 0;
		virtual bool IsVSync() const = 0;

		static Window* Creat(const WindowProps& props = WindowProps());

	};
}

实现类：

创建文件夹src/Platform/Windows

WindowsWindow.h:

#pragma once
#include "YOTO/Window.h"
#include<GLFW/glfw3.h>
#include"YOTO/Log.h"
namespace YOTO {
	class WindowsWindow :public Window
	{
	public :
		WindowsWindow(const WindowProps& props);
		virtual ~WindowsWindow();
		void OnUpdate() override;
		
		inline unsigned int GetWidth() const override { return m_Data.Width; };
		inline unsigned int GetHeight() const override { return m_Data.Height; };

		inline void SetEventCallback(const EventCallbackFn& callback)override { m_Data.EventCallback = callback; };
		void SetVSync(bool enable) ;
		bool IsVSync()const;
	private: 
		virtual void Init(const WindowProps& props);
		virtual void ShutDown();
	private:
		GLFWwindow* m_Window;
		struct WindowData {
			std::string Title;
			unsigned int Width, Height;
			bool VSync;
			EventCallbackFn EventCallback;
		};
		WindowData m_Data;
	};
}

 WindowsWindow.cpp:

#include "ytpch.h"
#include "WindowsWindow.h"

namespace YOTO {

	static bool s_GLFWInitialized = false;

	Window* Window::Creat(const WindowProps& props) {
		return new WindowsWindow(props);
	}
	WindowsWindow::WindowsWindow(const WindowProps& props) {
		Init(props);
	}
	WindowsWindow::~WindowsWindow() {
		ShutDown();
	}

	void WindowsWindow::Init(const WindowProps& props) {
		m_Data.Title = props.Title;
		m_Data.Width = props.Width;
		m_Data.Height = props.Height;
		YT_CORE_INFO("创建了{0},{1},{2}", props.Title, props.Width, props.Height);
		if (!s_GLFWInitialized) {
			int success = glfwInit();
			YT_CLIENT_ASSERT("不能创建新的glfw,{0}", success);
			s_GLFWInitialized = true;

		}
		m_Window = glfwCreateWindow((int)props.Width, (int)props.Height, m_Data.Title.c_str(), nullptr, nullptr);
		glfwMakeContextCurrent(m_Window); 
		glfwSetWindowUserPointer(m_Window, &m_Data);
		SetVSync(true);
	}
	void WindowsWindow::ShutDown() {
		glfwDestroyWindow(m_Window);
	}
	void WindowsWindow::OnUpdate()
	{
		//轮询事件
		glfwPollEvents();
		//交换缓冲区
		glfwSwapBuffers(m_Window);


	}
	void WindowsWindow::SetVSync(bool enable) {
		if (enable)
			glfwSwapInterval(1);
		else
			glfwSwapInterval(0);
		m_Data.VSync = enable;
		}
	bool WindowsWindow::IsVSync() const {
		return m_Data.VSync;
		}
}

Core.h:添加新的Error

#pragma once
//用于dll的宏
#ifdef YT_PLATFORM_WINDOWS
#ifdef YT_BUILD_DLL
#define YOTO_API __declspec(dllexport) 
#else
#define YOTO_API __declspec(dllimport) 

#endif // DEBUG
#else
#error YOTO_ONLY_SUPPORT_WINDOWS
#endif // YOTO_PLATFORM_WINDOWS

#ifdef YT_ENABLE_ASSERTS
#define YT_CLIENT_ASSERT(x,...) {if(!(x)){YT_CLIENT_ERROR("断言错误：{0}",__VA_ARGS__);__debugbreak();}}
#define YT_CORE_ASSERT(x,...) {if(!(x)){YT_CORE_ERROR("断言错误：{0}",__VA_ARGS__);__debugbreak();}}
#else
#define YT_ASSERT(x,...)
#define YT_CORE_ASSERT(x,...)

#endif // YT_ENABLE_ASSERTS



#define BIT(x)(1<<x)

Application.h:创建智能指针作为窗口的指针

#pragma once
#include"Core.h"
#include"Event/Event.h"
#include <YOTO/Window.h>

namespace YOTO {
	class YOTO_API Application
	{
	public:
		Application();
		virtual ~Application();
		void Run();
	private:
		std::unique_ptr<Window>  m_Window;
		bool m_Running = true;
	};
	//在客户端定义
	Application* CreateApplication();
}

测试：

Application.cpp:在构造函数中创建窗口，在run的while循环中调用Update，写一段opengl测试代码窗口改变颜色

#include"ytpch.h"
#include "Application.h"
#include"Event/ApplicationEvent.h"
#include"Log.h"
#include<GLFW/glfw3.h>
namespace YOTO {
	Application::Application() {
		//智能指针
		m_Window = std::unique_ptr<Window>(Window::Creat());
	}
	Application::~Application() {

	}
	void Application::Run() {
		WindowResizeEvent e(1280, 720);
		if (e.IsInCategory(EventCategoryApplication)) {
			YT_CORE_TRACE(e);
		}
		if (e.IsInCategory(EventCategoryInput)) {
			YT_CORE_ERROR(e);
		}

		while (m_Running)
		{
			glClearColor(1,0,1,1);
			glClear(GL_COLOR_BUFFER_BIT);
			m_Window->OnUpdate();
		}
	}
}

 BUG:只需要重新生成一下YOTOEngine就好了

BUG:可抽象的一个bug。原因是WindowsWindow.cpp错误的添加了#include"YOTO.h"把它删掉就好了。

结果：

窗口事件：

核心机制：

        在windowswindow.cpp的Init方法中，绑定GLFW回调，每次glfw发生某事件之后，调用回调函数。

        在Application.cpp的构造函数中，将所有事件绑定到OnEvent，通过多态传进来的事件信息，用EventDispatcher判断事件类型，并且调用绑定的事件。

Application.h：添加了OnEvent和OnWindowClosed的定义

#pragma once
#include"Core.h"
#include"Event/Event.h"
#include"Event/ApplicationEvent.h"
#include "YOTO/Window.h"

namespace YOTO {
	class YOTO_API Application
	{
	public:
		Application();
		virtual ~Application();
		void Run();
		void OnEvent(Event &e);
	private:
		bool  OnWindowClosed(WindowCloseEvent& e);
		std::unique_ptr<Window>  m_Window;
		bool m_Running = true;
	};
	//在客户端定义
	Application* CreateApplication();
}

Application.cpp： 绑定了OnEvent和OnWindowClosed

#include"ytpch.h"
#include "Application.h"

#include"Log.h"
#include<GLFW/glfw3.h>
namespace YOTO {
#define BIND_EVENT_FN(x) std::bind(&x, this, std::placeholders::_1)
	Application::Application() {
		//智能指针
		m_Window = std::unique_ptr<Window>(Window::Creat());
		//设置回调函数
		m_Window->SetEventCallback(BIND_EVENT_FN(Application::OnEvent));
	}
	/// <summary>
	/// 所有的Window事件都会在这触发，作为参数e
	/// </summary>
	/// <param name="e"></param>
	void Application::OnEvent(Event& e) {
		//根据事件类型绑定对应事件
		EventDispatcher dispatcher(e);
		dispatcher.Dispatch<WindowCloseEvent>(BIND_EVENT_FN(Application::OnWindowClosed));
		//输出事件信息
		YT_CORE_INFO("{0}",e);
	}
	Application::~Application() {

	}
	bool Application::OnWindowClosed(WindowCloseEvent& e) {
		m_Running = false;
		return true;
	}
	void Application::Run() {
		WindowResizeEvent e(1280, 720);
		if (e.IsInCategory(EventCategoryApplication)) {
			YT_CORE_TRACE(e);
		}
		if (e.IsInCategory(EventCategoryInput)) {
			YT_CORE_ERROR(e);
		}

		while (m_Running)
		{
			glClearColor(1,0,1,1);
			glClear(GL_COLOR_BUFFER_BIT);
			m_Window->OnUpdate();
		}
	}
}

WindowsWindow.cpp:Init方法事件添加回调（lambda表达式）

#include "ytpch.h"
#include "WindowsWindow.h"
#include"YOTO/Event/ApplicationEvent.h"
#include"YOTO/Event/MouseEvent.h"
#include"YOTO/Event/KeyEvent.h"
namespace YOTO {

	static bool s_GLFWInitialized = false;

	Window* Window::Creat(const WindowProps& props) {
		return new WindowsWindow(props);
	}
	WindowsWindow::WindowsWindow(const WindowProps& props) {
		Init(props);
	}
	WindowsWindow::~WindowsWindow() {
		ShutDown();
	}

	void WindowsWindow::Init(const WindowProps& props) {
		m_Data.Title = props.Title;
		m_Data.Width = props.Width;
		m_Data.Height = props.Height;
		YT_CORE_INFO("创建了{0},{1},{2}", props.Title, props.Width, props.Height);
		if (!s_GLFWInitialized) {
			int success = glfwInit();
			YT_CLIENT_ASSERT("不能创建新的glfw,{0}", success);
			glfwSetErrorCallback([](int error_code, const char* description) {
				YT_CORE_ERROR("GLFW错误:错误码({0})：{1} ", error_code, description);
				});
			s_GLFWInitialized = true;

		}
		m_Window = glfwCreateWindow((int)props.Width, (int)props.Height, m_Data.Title.c_str(), nullptr, nullptr);
		glfwMakeContextCurrent(m_Window); 
		glfwSetWindowUserPointer(m_Window, &m_Data);
		SetVSync(true);


		//GLFW回调，每次改变调用lambda里的部分
		glfwSetWindowSizeCallback(m_Window, [](GLFWwindow* window, int width, int height) {
			WindowData& data=*(WindowData*)glfwGetWindowUserPointer(window);
			data.Width = width;
			data.Height = height;
			WindowResizeEvent event(width, height);
			//调用回调函数
			data.EventCallback(event);
			});
		glfwSetWindowCloseCallback(m_Window, [](GLFWwindow* window) {
			WindowData& data = *(WindowData*)glfwGetWindowUserPointer(window);
			WindowCloseEvent event;
			data.EventCallback(event);
			});
		glfwSetKeyCallback(m_Window, [](GLFWwindow* window, int key, int scancode, int action, int mods) {
			WindowData& data = *(WindowData*)glfwGetWindowUserPointer(window);
			switch (action) {
				case GLFW_PRESS:
				{
					KeyPressedEvent event(key, 0);
					data.EventCallback(event);
					break;
				}
				case GLFW_RELEASE:
				{
					KeyReleasedEvent event(key);
					data.EventCallback(event);
					break;
				}
				case GLFW_REPEAT:
				{
					KeyPressedEvent event(key, 1);
					data.EventCallback(event);
					break;
				}
				}
			});
		glfwSetMouseButtonCallback(m_Window, [](GLFWwindow* window, int button, int action, int mods) {
			WindowData& data = *(WindowData*)glfwGetWindowUserPointer(window);
			switch (action)
			{
				case GLFW_PRESS:
				{
					MouseButtonPressedEvent event(button);
					data.EventCallback(event);
					break;
				}

				case GLFW_RELEASE:
				{
					MouseButtonReleasedEvent event(button);
					data.EventCallback(event);
					break;
				}
			}
			});
		glfwSetScrollCallback(m_Window, [](GLFWwindow* window, double xoffset, double yoffset) {
			WindowData& data = *(WindowData*)glfwGetWindowUserPointer(window);
			MouseScrolledEvent event((float)xoffset, (float)yoffset);
			data.EventCallback(event);
			});
		glfwSetCursorPosCallback(m_Window, [](GLFWwindow* window, double xpos, double ypos) {
			WindowData& data = *(WindowData*)glfwGetWindowUserPointer(window);
			MouseMovedEvent event((float)xpos, (float)ypos);
			data.EventCallback(event);
			});
	}
	void WindowsWindow::ShutDown() {
		glfwDestroyWindow(m_Window);
	}
	void WindowsWindow::OnUpdate()
	{
		//轮询事件
		glfwPollEvents();
		//交换缓冲区
		glfwSwapBuffers(m_Window);


	}
	void WindowsWindow::SetVSync(bool enable) {
		if (enable)
			glfwSwapInterval(1);
		else
			glfwSwapInterval(0);
		m_Data.VSync = enable;
		}
	bool WindowsWindow::IsVSync() const {
		return m_Data.VSync;
		}
}

测试：

cool 运行成功，事件系统投入使用。

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