#include <stdio.h>
#include <unistd.h>
#include "SDL.h"
#include "SDL_image.h"

#define DEBUG 0
#define SDL_VIDEO_FLAGS (SDL_HWSURFACE | SDL_DOUBLEBUF | SDL_ANYFORMAT | SDL_RESIZABLE)


#define LARGEUR 70
#define HAUTEUR 70



static void process_events( void ){

//#define LARGEUR 26
//#define HAUTEUR 16

//#define LARGEUR 166
//#define HAUTEUR 100


    /* Our SDL event placeholder. */
    SDL_Event event;

    /* Grab all the events off the queue. */
    while( SDL_PollEvent( &event ) ) {
        switch( event.type ) {
        case SDL_KEYDOWN:
            /* Handle key presses. */
	  if((&event.key.keysym) ->sym == SDLK_ESCAPE){
	    SDL_Quit();
	  exit(0);
	  }
            break;

        case SDL_QUIT:
            /* Handle quit requests (like Ctrl-c). */
	  SDL_Quit();
	  exit(0);
            break;

        default:
            break;
        }
    }
}





int main(int argc, char * argv[]){
  SDL_Surface * screen;
  SDL_Surface * dots[16];
  char filename[16];
  unsigned char wall[LARGEUR][HAUTEUR];
  int i, j;
  unsigned char n, nn, direction;
  
  for(i=0;i<16;i++){
    sprintf(filename,"dots/%X.png",i);
    dots[i]= IMG_Load(filename);
    if(!dots[i]){
      printf ( "IMG_Load: %s\n", IMG_GetError () );
      return 1;
    }
  }
  for(i=0;i<LARGEUR;i++){
    for(j=0;j<HAUTEUR;j++){
      wall[i][j]= 0;
    }
  }
  if (SDL_Init(SDL_INIT_VIDEO) == -1){
    printf("Erreur lors de l'initialisation de SDL: %s\n", SDL_GetError());
    return 1;
  }
 
  screen = SDL_SetVideoMode(LARGEUR*10, HAUTEUR*10, 24, SDL_VIDEO_FLAGS);
  printf("Mode video: %dx%dx%d\n", screen->w, screen->h, 
	 screen->format->BitsPerPixel);
  SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, 0,0,0)) ;
  
//  i=13;
//  j=7;
  i=LARGEUR / 2;
  j=(HAUTEUR / 2) -1;

  direction=1;
  while (1) {
    if(DEBUG) 	  printf("pos %d / %d col : %d !!! \n",i,j,wall[i][j]);
    //wall[i][j]= (wall[i][j]+1)%16;
    n=wall[i][j];
    switch(n){
      case 0:
	nn=7;
	direction=direction+3;
	break;
      case 7:
	nn=11;
	direction=direction+1;
	break;
      case 11:
	nn=15;
	direction=direction+1;
	break;
      case 15:
	nn=0;
	direction=direction+3;
	break;
    }
    wall[i][j]=nn;
    direction = direction % 4;
    SDL_Rect dest={10*i,10*j,0,0};
    //SDL_BlitSurface(dots[n],NULL,screen,&dest);
    SDL_BlitSurface(dots[nn],NULL,screen,&dest);
    //direction = (direction+1 +  2*(((nn/4 )%2))) % 4;
    
    SDL_UpdateRect(screen,10*i,10*j,10,10);
    if(DEBUG) printf("direction=%i\n",direction);
	switch(direction){
	      case 0:
		j=j-1;
		if (j<0) {
		  //j=15;
		  j=HAUTEUR -1	;
		  //direction=direction+2;
		}
		break;
	      case 1:
		i=i+1;
		//if (i>25) {
		if (i> (LARGEUR - 1)) {
		 i=0;
		 //direction=direction+2;
		}
		break;
	      case 2:
		j=j+1;
		//if (j>15) {
		if (j>(HAUTEUR -1)) {
		 j=0;
		 //direction=direction+2;
		}
		break;
	      case 3:
		i=i-1;
		if (i<0) {
		 //i=25;
		 i=LARGEUR - 1;
		 //direction=direction+2;
		}
		break;
	    }
	    direction = direction % 4;
    SDL_Flip(screen);
    process_events();
    usleep(2);
  }
  SDL_Quit();
  return 0;
}