/*
 * Trevor's utility to display empeg logos
 *
 * Copyright (C) 2003 Trevor Man
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include "hijack.h"

inline unsigned long get_long(unsigned char *ptr);
inline unsigned int get_short(unsigned char *ptr);

int main(int argc, char *argv[])
{
  int display_fd;
  int input_fd;
  caddr_t display;
  caddr_t input;
  unsigned long offset;
  unsigned int frame;
  unsigned int tmp;
  unsigned int tmp2;
  struct stat stat_buf;
  struct timeval timeout;

  fprintf(stderr, "EmpView v1.0 - Copyright 2004 - Trevor Man\n");

  if (argc != 2) {
    fprintf(stderr, "%s bmp_file/raw_ani_file\n", argv[0]);
    return 1;
  }

  if ((input_fd = open(argv[1], O_RDONLY)) == -1) {
    fprintf(stderr, "Unable to open %s for reading.\n", argv[1]);
    return 1;
  }

  if ((display_fd = open("/dev/display", O_RDWR)) == -1) {
    fprintf(stderr, "Unable to open display.\n");
    return 1;
  }

  if (fstat(input_fd, &stat_buf) == -1) {
    fprintf(stderr, "Unable to stat %s\n.", argv[1]);
    return 1;
  }  

  if ((input = mmap(0, stat_buf.st_size, PROT_READ, MAP_SHARED, input_fd, 0)) == (caddr_t)-1) {
    fprintf(stderr, "Unable to map %s\n", argv[1]);
    return 1;
  }

  if ((display = mmap(0, 2048, PROT_READ | PROT_WRITE, MAP_SHARED, display_fd, 0)) == (caddr_t)-1) {
    fprintf(stderr, "Unable to map display.\n");
    return 1;
  }

  if (*input == 'G' && *(input + 1) == 'I' && *(input + 2) == 'F') {
    fprintf(stderr, "GIF format files are not supported currently.\n");
  } else if (*(input + 6) == 'J' && *(input + 7) == 'F' && *(input + 8) == 'I' && *(input + 9) == 'F') {
    fprintf(stderr, "JPEG format files are not supported currently.\n");
  } else if (*input == 'B' && *(input + 1) == 'M') {
    if (get_long(input + 2) != stat_buf.st_size) {
      fprintf(stderr, "Corrupt BMP file\n");
    } else if (get_long(input + 18) != 128 ||
               get_long(input + 22) != 32 ||
               get_short(input + 28) != 24 ||
               get_short(input + 30) != 0) {
      fprintf(stderr, "Unsupported BMP format.  Must be 128x32@24 uncompressed.\n");
    } else {
      for (tmp = 0; tmp < 32; tmp++) {
        for (tmp2 = 0; tmp2 < 64; tmp2++) {
          *(display + tmp * 64 + tmp2) = ((*(input + get_long(input + 10) + ((32 - tmp - 1) * 128 + 2 * tmp2) * 3)) & 0x0F) |
                                         ((*(input + get_long(input + 10) + ((32 - tmp - 1) * 128 + 2 * tmp2 + 1) * 3)) & 0xF0);
        }
      }
      ioctl(display_fd, _IOW('d', 1, int), 1);
      ioctl(display_fd, _IO('d', 0));
    }
  } else {
    ioctl(display_fd, _IOW('d', 1, int), 1);

    for (frame = 0; ; frame++) {
      if ((offset = ((unsigned long *)input)[frame]) == 0)
        break;
      if (offset + 1024 - 1> stat_buf.st_size) {
        fprintf(stderr, "Corrupt file.  Aborting.\n");
        break;
      }

      for (tmp = 0; tmp < 2048; tmp += 2) {
        *(display + tmp) = ((*(input + offset + (tmp / 2)) & 0xc0) >> 2) |
                           ((*(input + offset + (tmp / 2)) & 0x30) >> 4);
        *(display + tmp + 1) = ((*(input + offset + (tmp / 2)) & 0x0c) << 2) |
                               ((*(input + offset + (tmp / 2)) & 0x03));
      }

      ioctl(display_fd, _IO('d', 0));

      timeout.tv_sec = 0;
      timeout.tv_usec = 1000000 / 12;
      select(0, NULL, NULL, NULL, &timeout);
    }
  }

  if (munmap(display, 2048) == -1) {
    fprintf(stderr, "Unable to unmap display.\n");
  }

  if (munmap(input, stat_buf.st_size) == -1) {
    fprintf(stderr, "Unable to unmap %s.\n", argv[1]);
  }

  close(input_fd);
  close(display_fd);

  return 0;
}

inline unsigned long get_long(unsigned char *ptr)
{
  return *ptr | *(ptr + 1) << 8 | *(ptr + 2) << 16 | *(ptr + 3) << 24;
}

inline unsigned int get_short(unsigned char *ptr)
{
  return *ptr | *(ptr + 1) << 8;
}