#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

unsigned short
PixelCreate(int r, int g, int b)
{
   r >>= 3;
   g >>= 3;
   b >>= 3;
   
   return
      ((r & 31) << 10) |
      ((g & 31) <<  5) |
      ((b & 31) <<  0) ;
}

int
PPMRead(FILE* file)
{
   char s[256];

   fscanf(file, "%s", s);
         
   while (s[0] == '#') fscanf(file, "%[^\n]%c%s", s, s, s); 
         
   return atoi(s);
}

void
main(int argc, char* argv[])
{
   char  full_path[_MAX_PATH];
   char  drive[_MAX_DRIVE];
   char  dir[_MAX_DIR];
   char  fname[_MAX_FNAME];
   char  ext[_MAX_EXT];
   char  s[256];
   int  i, x, y, r, g, b, width, height, depth;
   unsigned short pixel;
   FILE* outfile;
   FILE* infile;
   
   for (i = 1; i < argc; i++)
   {
      _splitpath(argv[i], drive, dir, fname, ext);
      _makepath(full_path, drive, dir, fname, "hic");

      fprintf(stderr, "Converting: '%s' to '%s'\n", argv[i], full_path);
      
      infile = fopen(argv[i], "r");

      assert(infile);

      outfile = fopen(full_path, "wb");

      assert(outfile);
   
      fscanf(infile, "%s", s);
   
      assert(!strcmp(s, "P3"));
   
      width  = PPMRead(infile);
      height = PPMRead(infile);
      depth  = PPMRead(infile);
   
      assert(depth == 255);
      
      fwrite(&width , sizeof(int), 1, outfile);
      fwrite(&height, sizeof(int), 1, outfile);
      
      for (y = 0; y < height; y++)
      {
         for (x = 0; x < width; x++)
         {
            fscanf(infile, "%d%d%d", &r, &g, &b);
   
            pixel = PixelCreate(r, g, b);
   
            fwrite(&pixel, sizeof(short), 1, outfile);
         }
      }

      fclose(infile);
      fclose(outfile);
   }
}