SDL多线程显示更新窗口

//初始化SDL2和创建一个窗口，并且将屏幕绘制成大红色
#include <iostream>
extern "C"
{
#include <SDL.h>
}

//Refresh Event
#define REFRESH_EVENT	(SDL_USEREVENT + 1)
#define BREAK_EVENT		(SDL_USEREVENT + 2)

bool thread_exit = false;

int threadFunc(void *opaque)
{
	thread_exit = false;
	while (!thread_exit)
	{
		SDL_Event event;
		event.type = REFRESH_EVENT;
		SDL_PushEvent(&event);
		SDL_Delay(40);
	}
	thread_exit = true;
	//Break  
	SDL_Event event;
	event.type = BREAK_EVENT;
	//发送一个事件
	SDL_PushEvent(&event);
	return 0;
}

int main(int argc, char* argv[])
{
	SDL_Window *windowScreen = NULL;	//窗口
	SDL_Surface *windowSurface = NULL;//窗口表面
	SDL_Thread *refresh_thread;		//SDL线程
	SDL_Event event;					//SDL事件
	
	//初始化SDL2
	if (SDL_Init(SDL_INIT_VIDEO) == -1)
	{
		std::cout << SDL_GetError() << std::endl;
		return -1;
	}

	/* 创建窗口
	*第一个参数是窗口的标题
	*第二、三个参数指明了窗口的位置信息
	*第四、五个参数是窗口的大小（宽、高）
	*第六个参数是窗口的状态
	*SDL_WINDOW_SHOWN--显示窗口
	*SDL_WINDOW_BORDERLESS--显示无边框窗口
	*/
	windowScreen = SDL_CreateWindow("title", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 240, 400, SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE);
	if (!windowScreen)
	{
		std::cout << SDL_GetError() << std::endl;
		return -1;
	}
	
	//创建线程
	refresh_thread = SDL_CreateThread(threadFunc, NULL, NULL);
	if (refresh_thread == NULL)
	{
		std::cout << SDL_GetError() << std::endl;
		return -1;
	}

	//事件(消息)循环
	while (true)
	{
		//等待一个事件(类似于WIN32里的GetMessage)
		SDL_WaitEvent(&event);
		if (event.type == REFRESH_EVENT)
		{
			/*填充窗口
			*第一个参数是填充的目标表面
			*第二个是填充的矩形区域(NULL则表示默认全部填充)
			*第三个参数是填充矩形用的颜色
			*/
			SDL_FillRect(windowSurface, NULL, SDL_MapRGB(windowSurface->format, 0xFF, 0x00, 0x00));
			
			//将窗口表面加载到窗口
			SDL_UpdateWindowSurface(windowScreen);
		}
		else if (event.type == SDL_QUIT)
		{
			thread_exit = true;
		}
		else if (event.type == SDL_WINDOWEVENT)
		{
			// 获取窗口的表面
			windowSurface = SDL_GetWindowSurface(windowScreen);
			if (!windowSurface)
			{
				std::cout << SDL_GetError() << std::endl;
				return -1;
			}
		}
		else if (event.type == BREAK_EVENT)
		{
			break;
		}
	}

	SDL_FreeSurface(windowSurface);
	SDL_DestroyWindow(windowScreen);
	SDL_Quit();
	return 0;
}




/*配置
1.VC++目录 include lib dll
2.链接器->输入->附加依赖项 SDL2.lib SDL2main.lib
3.链接器->系统->子系统  窗口 (/SUBSYSTEM:WINDOWS)  控制台 (/SUBSYSTEM:CONSOLE)
4.C++->代码生成->运行库 /MD
编译
cl /MD /c c.cpp
链接
link /SUBSYSTEM:CONSOLE c.obj SDL2.lib SDL2main.lib
*/