sdl_hello.c

Linux嵌入式设计配套光盘,学习嵌入式设计可参考

/****************************************************************************
 * sdl_hello.c
 *
 * Demonstrate a minimal SDL program to display "Hello, world!".
 ****************************************************************************/
#include "SDL.h"                /* All SDL App's need this */
#include "SDL_ttf.h"            /* Truetype fonts */

int main(int argc, char *argv[]) {
  SDL_Surface *Screen;
  SDL_Surface *helloSurface;

  TTF_Font *helloFont;
  SDL_Color helloColor = {128,128,255,0}; /* light blue */
  SDL_Rect  helloRect  = {150,100,0,0};   /* set x,y; w,h filled in later */

  SDL_Event event;
  int       enableQuit;

  if((SDL_Init(SDL_INIT_VIDEO)==-1)) { 
    fprintf(stderr, "Could not initialize SDL: %s.\n", SDL_GetError());
    exit(1);
  }

  atexit(SDL_Quit);             /* Schedule clean up on exit. */
    
  /* Initialize the display in a 640x480 8-bit palettized mode. */
  Screen = SDL_SetVideoMode(640, 480, 8, 0);
  if ( Screen == NULL ) {
    fprintf(stderr, "Couldn't set 640x480x8 video mode: %s\n",
            SDL_GetError());
    exit(1);
  }

  SDL_ShowCursor(SDL_DISABLE);  /* Hide the mouse cursor. */

  if(TTF_Init() == -1) {
    fprintf(stderr, "TTF_Init: %s\n", TTF_GetError());
    exit(-1);
  }

  atexit(TTF_Quit);             /* Schedule clean up on exit. */

  /* Open a font and create a text surface for "Hello, world!" */
  helloFont = TTF_OpenFont("/usr/local/share/fonts/bitstream/VeraBI.ttf", 42);
  helloSurface = TTF_RenderText_Solid(helloFont, "Hello, world!", helloColor);

  /* Blit the text surface to the screen surface. This will update helloRect
     with the actual blitting rectangle, thus recording helloSurface's width
     and height. */
  SDL_BlitSurface(helloSurface, NULL, Screen, &helloRect);

  /* Update the portion of the screen containing the new text. */
  SDL_UpdateRects(Screen, 1, &helloRect);

  enableQuit = 0;
  while(!enableQuit){

    SDL_WaitEvent(&event);

    switch(event.type){  /* Process the appropiate event type */
      case SDL_KEYDOWN:
        /* Respond to keys that are significant for the application. */
        switch(event.key.keysym.sym){
          case SDLK_SPACE:
          case SDLK_ESCAPE:	/* make it easy to exit */
          case SDLK_RETURN:
            enableQuit = 1;
            break;

          case SDLK_s:
            SDL_SaveBMP(Screen, "/tmp/Screen.bmp");
            break;
        }
        break;
    }
  }

  SDL_ShowCursor(SDL_ENABLE);  /* Hide the mouse cursor. */

  exit(0);                      /* SDL_Quit and TTF_Quit called on exit. */
}