SDL2.0学习教程（一）——显示一张Hello World图片

英文版作者代码：https://github.com/Twinklebear/TwinklebearDev-Lessons

中文版翻译：http://adolfans.github.io/sdltutorialcn/blog/2013/01/26/lesson-1-hello-world/

觉得中文版翻译讲得有些繁琐，就按照自己的理解，整理如下：

代码：

#include <iostream>
#include <SDL.h>

int main(int, char**)
{
    if (SDL_Init(SDL_INIT_VIDEO))
    {
        std::cout << "SDL_Init Error: " << SDL_GetError() << std::endl;
        return 1;
    }

    SDL_Window *win = SDL_CreateWindow("Hello World!", 100, 100, 640, 480, SDL_WINDOW_SHOWN);

    if (win == nullptr)
    {
        std::cout << "SDL_CreateWindow Error: " << SDL_GetError() << std::endl;
        return 1;
    }

    SDL_Renderer *ren = SDL_CreateRenderer(win, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
    if (ren == nullptr)
    {
        SDL_DestroyWindow(win);
        std::cout << "SDL_CreateRender Error: " << SDL_GetError() << std::endl;
        SDL_Quit();
        return 1;
    }

    std::string imagePath = "hello.bmp";
    SDL_Surface *bmp = SDL_LoadBMP(imagePath.c_str());
    if (bmp == nullptr)
    {
        SDL_DestroyRenderer(ren);
        SDL_DestroyWindow(win);
        std::cout << "SDL_LoadBMP Error: " << SDL_GetError() << std::endl;
        SDL_Quit();
        return 1;
    }

    SDL_Texture *tex = SDL_CreateTextureFromSurface(ren, bmp);

    SDL_FreeSurface(bmp);
    if (tex == nullptr)
    {
        SDL_DestroyRenderer(ren);
        SDL_DestroyWindow(win);
        std::cout << "SDL_CreateTextureFromSurface Error: " << SDL_GetError() << std::endl;
        SDL_Quit();
        return 1;
    }

    for (int i = 0; i < 3; ++i)
    {
        SDL_RenderClear(ren);
        SDL_RenderCopy(ren, tex, NULL, NULL);
        SDL_RenderPresent(ren);
        SDL_Delay(1000);
    }

    SDL_DestroyTexture(tex);
    SDL_DestroyRenderer(ren);
    SDL_DestroyWindow(win);
    SDL_Quit();

    return 0;
}

 初始化: 

SDL_Init(): 初始化SDL。 
SDL_CreateWindow(): 创建窗口（Window）。 
SDL_CreateRenderer(): 基于窗口创建渲染器（Render）。 
SDL_CreateTexture(): 创建纹理（Texture）。 

循环渲染数据: 

SDL_UpdateTexture(): 设置纹理的数据。 
SDL_RenderCopy(): 纹理复制给渲染器。 
SDL_RenderPresent(): 显示。

具体参考：http://blog.csdn.net/leixiaohua1020/article/details/40680907