sdl笔记

阅读更多

sdl教程教程
https://github.com/Twinklebear/TwinklebearDev-Lessons

asm.js的教程
https://github.com/3dgen/cppwasm-book
入门
http://www.ruanyifeng.com/blog/2017/09/asmjs_emscripten.html



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vim格式化：
1，gg 跳转到第一行
2，shift+v 转到可视模式
3，shift+g 全选
4，按下神奇的 =


centos7安装

yum install SDL SDL-devel SDL-static -y
helloworld
https://www.linuxidc.com/Linux/2012-12/75255.htm

main.c

#include "SDL/SDL.h"  
int main( int argc, char* args[] )  
{  
    //Start SDL  
    SDL_Init( SDL_INIT_EVERYTHING );  
    //Quit SDL  
    SDL_Quit();  
    return 0;      
} 

emscripten 加载文件
https://github.com/3dgen/cppwasm-book/blob/master/zh/ch3-runtime/ch3-03-fs.md

加载一张图片

#include 
#include 
int main()
{
    //The images
    SDL_Surface* hello = NULL;
    SDL_Surface* screen = NULL;
    SDL_Init( SDL_INIT_EVERYTHING );
    //Set up screen
    screen = SDL_SetVideoMode( 640, 480, 32, SDL_SWSURFACE );
    //Load image
    //hello = SDL_LoadBMP( "1.bmp" );
    hello = SDL_LoadBMP( "1.bmp" );
    //Apply image to screen
    SDL_BlitSurface( hello, NULL, screen, NULL );
    //Update Screen
    SDL_Flip( screen );
    //Pause
    SDL_Delay( 5000 );
    //Quit SDL
    SDL_Quit();
    //Free memory
    SDL_FreeSurface( hello );
    //Quit SDL
    SDL_Quit();
    return 0;
}

############################


emcc使用sdl2
emcc main.c -s USE_SDL=2 -o main.html



https://blog.csdn.net/pkx1993/article/details/82015659?utm_source=blogxgwz4

Emscripten Ports

有用库的收集，并移植到Emscripten。Github地址：https://github.com/emscripten-ports

他们已经被整合到了emcc中。当你请求一个ports被使用时，emcc会从远程服务器获取，设置并在本地构建它，然后将其链接到您的项目，向您的构建命令添加必需的包含。
例如：SDL2是一个ports，可以请求并并使用命令-s USE_SDL=2链接他。

emcc tests/sdl2glshader.c -s USE_SDL=2 -s LEGACY_GL_EMULATION=1 -o sdl2.html

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SDL入门教程：
https://segmentfault.com/a/1190000011328496

emscripten 加载sdl的helloworld
hello_world_cube.cpp

#include 
#include 

#ifdef __EMSCRIPTEN__
#include 
#endif

extern "C" int main(int argc, char** argv) {
  printf("hello, world!\n");

  SDL_Init(SDL_INIT_VIDEO);
  SDL_Surface *screen = SDL_SetVideoMode(256, 256, 32, SDL_SWSURFACE);

#ifdef TEST_SDL_LOCK_OPTS
  EM_ASM("SDL.defaults.copyOnLock = false; SDL.defaults.discardOnLock = true; SDL.defaults.opaqueFrontBuffer = false;");
#endif

  if (SDL_MUSTLOCK(screen)) SDL_LockSurface(screen);
  for (int i = 0; i < 256; i++) {
    for (int j = 0; j < 256; j++) {
#ifdef TEST_SDL_LOCK_OPTS
      // Alpha behaves like in the browser, so write proper opaque pixels.
      int alpha = 255;
#else
     // To emulate native behavior with blitting to screen, alpha component is ignored. Test that it is so by outputting
      // data (and testing that it does get discarded)
      int alpha = (i+j) % 255;
#endif
      *((Uint32*)screen->pixels + i * 256 + j) = SDL_MapRGBA(screen->format, i, j, 255-i, alpha);
    }
  }
  if (SDL_MUSTLOCK(screen)) SDL_UnlockSurface(screen);
  SDL_Flip(screen);

  printf("you should see a smoothly-colored square - no sharp lines but the square borders!\n");
  printf("and here is some text that should be HTML-friendly: amp: |&| double-quote: |\"| quote: |'| less-than, greater-than, html-like tags: ||\nanother line.\n");

  SDL_Quit();

  return 0;
}

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问题:
1.浏览器最基本的sdl
2.加载图片？