/*
   *  Convert a logo in ASCII PNM format to C source suitable for inclusion in
   *  the Linux kernel
   *
   *  (C) Copyright 2001-2003 by Geert Uytterhoeven <geert@linux-m68k.org>
   *
   *  --------------------------------------------------------------------------
   *
   *  This file is subject to the terms and conditions of the GNU General Public
   *  License. See the file COPYING in the main directory of the Linux
   *  distribution for more details.
   */
  
  #include <ctype.h>
  #include <errno.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  
  static const char *programname;
  static const char *filename;
  static const char *logoname = "linux_logo";
  static const char *outputname;
  static FILE *out;
  
  
  #define LINUX_LOGO_MONO		1	/* monochrome black/white */
  #define LINUX_LOGO_VGA16	2	/* 16 colors VGA text palette */
  #define LINUX_LOGO_CLUT224	3	/* 224 colors */
  #define LINUX_LOGO_GRAY256	4	/* 256 levels grayscale */
  
  static const char *logo_types[LINUX_LOGO_GRAY256+1] = {
      [LINUX_LOGO_MONO] = "LINUX_LOGO_MONO",
      [LINUX_LOGO_VGA16] = "LINUX_LOGO_VGA16",
      [LINUX_LOGO_CLUT224] = "LINUX_LOGO_CLUT224",
      [LINUX_LOGO_GRAY256] = "LINUX_LOGO_GRAY256"
  };
  
  #define MAX_LINUX_LOGO_COLORS	224
  
  struct color {
      unsigned char red;
      unsigned char green;
      unsigned char blue;
  };
  
  static const struct color clut_vga16[16] = {
      { 0x00, 0x00, 0x00 },
      { 0x00, 0x00, 0xaa },
      { 0x00, 0xaa, 0x00 },
      { 0x00, 0xaa, 0xaa },
      { 0xaa, 0x00, 0x00 },
      { 0xaa, 0x00, 0xaa },
      { 0xaa, 0x55, 0x00 },
      { 0xaa, 0xaa, 0xaa },
      { 0x55, 0x55, 0x55 },
      { 0x55, 0x55, 0xff },
      { 0x55, 0xff, 0x55 },
      { 0x55, 0xff, 0xff },
      { 0xff, 0x55, 0x55 },
      { 0xff, 0x55, 0xff },
      { 0xff, 0xff, 0x55 },
      { 0xff, 0xff, 0xff },
  };
  
  
  static int logo_type = LINUX_LOGO_CLUT224;
  static unsigned int logo_width;
  static unsigned int logo_height;
  static struct color **logo_data;
  static struct color logo_clut[MAX_LINUX_LOGO_COLORS];
  static unsigned int logo_clutsize;
  static int is_plain_pbm = 0;
  
  static void die(const char *fmt, ...)
      __attribute__ ((noreturn)) __attribute ((format (printf, 1, 2)));
  static void usage(void) __attribute ((noreturn));
  
  
  static unsigned int get_number(FILE *fp)
  {
      int c, val;
  
      /* Skip leading whitespace */
      do {
  	c = fgetc(fp);
  	if (c == EOF)
  	    die("%s: end of file
  ", filename);
  	if (c == '#') {
  	    /* Ignore comments 'till end of line */
  	    do {
  		c = fgetc(fp);
  		if (c == EOF)
  		    die("%s: end of file
  ", filename);
  	    } while (c != '
  ');
  	}
      } while (isspace(c));
  
      /* Parse decimal number */
      val = 0;
      while (isdigit(c)) {
  	val = 10*val+c-'0';
  	/* some PBM are 'broken'; GiMP for example exports a PBM without space
  	 * between the digits. This is Ok cause we know a PBM can only have a '1'
  	 * or a '0' for the digit. */
  	if (is_plain_pbm)
  		break;
  	c = fgetc(fp);
  	if (c == EOF)
  	    die("%s: end of file
  ", filename);
      }
      return val;
  }
  
  static unsigned int get_number255(FILE *fp, unsigned int maxval)
  {
      unsigned int val = get_number(fp);
      return (255*val+maxval/2)/maxval;
  }
  
  static void read_image(void)
  {
      FILE *fp;
      unsigned int i, j;
      int magic;
      unsigned int maxval;
  
      /* open image file */
      fp = fopen(filename, "r");
      if (!fp)
  	die("Cannot open file %s: %s
  ", filename, strerror(errno));
  
      /* check file type and read file header */
      magic = fgetc(fp);
      if (magic != 'P')
  	die("%s is not a PNM file
  ", filename);
      magic = fgetc(fp);
      switch (magic) {
  	case '1':
  	case '2':
  	case '3':
  	    /* Plain PBM/PGM/PPM */
  	    break;
  
  	case '4':
  	case '5':
  	case '6':
  	    /* Binary PBM/PGM/PPM */
  	    die("%s: Binary PNM is not supported
  "
  		"Use pnmnoraw(1) to convert it to ASCII PNM
  ", filename);
  
  	default:
  	    die("%s is not a PNM file
  ", filename);
      }
      logo_width = get_number(fp);
      logo_height = get_number(fp);
  
      /* allocate image data */
      logo_data = (struct color **)malloc(logo_height*sizeof(struct color *));
      if (!logo_data)
  	die("%s
  ", strerror(errno));
      for (i = 0; i < logo_height; i++) {
  	logo_data[i] = malloc(logo_width*sizeof(struct color));
  	if (!logo_data[i])
  	    die("%s
  ", strerror(errno));
      }
  
      /* read image data */
      switch (magic) {
  	case '1':
  	    /* Plain PBM */
  	    is_plain_pbm = 1;
  	    for (i = 0; i < logo_height; i++)
  		for (j = 0; j < logo_width; j++)
  		    logo_data[i][j].red = logo_data[i][j].green =
  			logo_data[i][j].blue = 255*(1-get_number(fp));
  	    break;
  
  	case '2':
  	    /* Plain PGM */
  	    maxval = get_number(fp);
  	    for (i = 0; i < logo_height; i++)
  		for (j = 0; j < logo_width; j++)
  		    logo_data[i][j].red = logo_data[i][j].green =
  			logo_data[i][j].blue = get_number255(fp, maxval);
  	    break;
  
  	case '3':
  	    /* Plain PPM */
  	    maxval = get_number(fp);
  	    for (i = 0; i < logo_height; i++)
  		for (j = 0; j < logo_width; j++) {
  		    logo_data[i][j].red = get_number255(fp, maxval);
  		    logo_data[i][j].green = get_number255(fp, maxval);
  		    logo_data[i][j].blue = get_number255(fp, maxval);
  		}
  	    break;
      }
  
      /* close file */
      fclose(fp);
  }
  
  static inline int is_black(struct color c)
  {
      return c.red == 0 && c.green == 0 && c.blue == 0;
  }
  
  static inline int is_white(struct color c)
  {
      return c.red == 255 && c.green == 255 && c.blue == 255;
  }
  
  static inline int is_gray(struct color c)
  {
      return c.red == c.green && c.red == c.blue;
  }
  
  static inline int is_equal(struct color c1, struct color c2)
  {
      return c1.red == c2.red && c1.green == c2.green && c1.blue == c2.blue;
  }
  
  static void write_header(void)
  {
      /* open logo file */
      if (outputname) {
  	out = fopen(outputname, "w");
  	if (!out)
  	    die("Cannot create file %s: %s
  ", outputname, strerror(errno));
      } else {
  	out = stdout;
      }
  
      fputs("/*
  ", out);
      fputs(" *  DO NOT EDIT THIS FILE!
  ", out);
      fputs(" *
  ", out);
      fprintf(out, " *  It was automatically generated from %s
  ", filename);
      fputs(" *
  ", out);
      fprintf(out, " *  Linux logo %s
  ", logoname);
      fputs(" */
  
  ", out);
      fputs("#include <linux/linux_logo.h>
  
  ", out);
      fprintf(out, "static unsigned char %s_data[] __initdata = {
  ",
  	    logoname);
  }
  
  static void write_footer(void)
  {
      fputs("
  };
  
  ", out);
      fprintf(out, "const struct linux_logo %s __initconst = {
  ", logoname);
      fprintf(out, "\t.type\t\t= %s,
  ", logo_types[logo_type]);
      fprintf(out, "\t.width\t\t= %d,
  ", logo_width);
      fprintf(out, "\t.height\t\t= %d,
  ", logo_height);
      if (logo_type == LINUX_LOGO_CLUT224) {
  	fprintf(out, "\t.clutsize\t= %d,
  ", logo_clutsize);
  	fprintf(out, "\t.clut\t\t= %s_clut,
  ", logoname);
      }
      fprintf(out, "\t.data\t\t= %s_data
  ", logoname);
      fputs("};
  
  ", out);
  
      /* close logo file */
      if (outputname)
  	fclose(out);
  }
  
  static int write_hex_cnt;
  
  static void write_hex(unsigned char byte)
  {
      if (write_hex_cnt % 12)
  	fprintf(out, ", 0x%02x", byte);
      else if (write_hex_cnt)
  	fprintf(out, ",
  \t0x%02x", byte);
      else
  	fprintf(out, "\t0x%02x", byte);
      write_hex_cnt++;
  }
  
  static void write_logo_mono(void)
  {
      unsigned int i, j;
      unsigned char val, bit;
  
      /* validate image */
      for (i = 0; i < logo_height; i++)
  	for (j = 0; j < logo_width; j++)
  	    if (!is_black(logo_data[i][j]) && !is_white(logo_data[i][j]))
  		die("Image must be monochrome
  ");
  
      /* write file header */
      write_header();
  
      /* write logo data */
      for (i = 0; i < logo_height; i++) {
  	for (j = 0; j < logo_width;) {
  	    for (val = 0, bit = 0x80; bit && j < logo_width; j++, bit >>= 1)
  		if (logo_data[i][j].red)
  		    val |= bit;
  	    write_hex(val);
  	}
      }
  
      /* write logo structure and file footer */
      write_footer();
  }
  
  static void write_logo_vga16(void)
  {
      unsigned int i, j, k;
      unsigned char val;
  
      /* validate image */
      for (i = 0; i < logo_height; i++)
  	for (j = 0; j < logo_width; j++) {
  	    for (k = 0; k < 16; k++)
  		if (is_equal(logo_data[i][j], clut_vga16[k]))
  		    break;
  	    if (k == 16)
  		die("Image must use the 16 console colors only
  "
  		    "Use ppmquant(1) -map clut_vga16.ppm to reduce the number "
  		    "of colors
  ");
  	}
  
      /* write file header */
      write_header();
  
      /* write logo data */
      for (i = 0; i < logo_height; i++)
  	for (j = 0; j < logo_width; j++) {
  	    for (k = 0; k < 16; k++)
  		if (is_equal(logo_data[i][j], clut_vga16[k]))
  		    break;
  	    val = k<<4;
  	    if (++j < logo_width) {
  		for (k = 0; k < 16; k++)
  		    if (is_equal(logo_data[i][j], clut_vga16[k]))
  			break;
  		val |= k;
  	    }
  	    write_hex(val);
  	}
  
      /* write logo structure and file footer */
      write_footer();
  }
  
  static void write_logo_clut224(void)
  {
      unsigned int i, j, k;
  
      /* validate image */
      for (i = 0; i < logo_height; i++)
  	for (j = 0; j < logo_width; j++) {
  	    for (k = 0; k < logo_clutsize; k++)
  		if (is_equal(logo_data[i][j], logo_clut[k]))
  		    break;
  	    if (k == logo_clutsize) {
  		if (logo_clutsize == MAX_LINUX_LOGO_COLORS)
  		    die("Image has more than %d colors
  "
  			"Use ppmquant(1) to reduce the number of colors
  ",
  			MAX_LINUX_LOGO_COLORS);
  		logo_clut[logo_clutsize++] = logo_data[i][j];
  	    }
  	}
  
      /* write file header */
      write_header();
  
      /* write logo data */
      for (i = 0; i < logo_height; i++)
  	for (j = 0; j < logo_width; j++) {
  	    for (k = 0; k < logo_clutsize; k++)
  		if (is_equal(logo_data[i][j], logo_clut[k]))
  		    break;
  	    write_hex(k+32);
  	}
      fputs("
  };
  
  ", out);
  
      /* write logo clut */
      fprintf(out, "static unsigned char %s_clut[] __initdata = {
  ",
  	    logoname);
      write_hex_cnt = 0;
      for (i = 0; i < logo_clutsize; i++) {
  	write_hex(logo_clut[i].red);
  	write_hex(logo_clut[i].green);
  	write_hex(logo_clut[i].blue);
      }
  
      /* write logo structure and file footer */
      write_footer();
  }
  
  static void write_logo_gray256(void)
  {
      unsigned int i, j;
  
      /* validate image */
      for (i = 0; i < logo_height; i++)
  	for (j = 0; j < logo_width; j++)
  	    if (!is_gray(logo_data[i][j]))
  		die("Image must be grayscale
  ");
  
      /* write file header */
      write_header();
  
      /* write logo data */
      for (i = 0; i < logo_height; i++)
  	for (j = 0; j < logo_width; j++)
  	    write_hex(logo_data[i][j].red);
  
      /* write logo structure and file footer */
      write_footer();
  }
  
  static void die(const char *fmt, ...)
  {
      va_list ap;
  
      va_start(ap, fmt);
      vfprintf(stderr, fmt, ap);
      va_end(ap);
  
      exit(1);
  }
  
  static void usage(void)
  {
      die("
  "
  	"Usage: %s [options] <filename>
  "
  	"
  "
  	"Valid options:
  "
  	"    -h          : display this usage information
  "
  	"    -n <name>   : specify logo name (default: linux_logo)
  "
  	"    -o <output> : output to file <output> instead of stdout
  "
  	"    -t <type>   : specify logo type, one of
  "
  	"                      mono    : monochrome black/white
  "
  	"                      vga16   : 16 colors VGA text palette
  "
  	"                      clut224 : 224 colors (default)
  "
  	"                      gray256 : 256 levels grayscale
  "
  	"
  ", programname);
  }
  
  int main(int argc, char *argv[])
  {
      int opt;
  
      programname = argv[0];
  
      opterr = 0;
      while (1) {
  	opt = getopt(argc, argv, "hn:o:t:");
  	if (opt == -1)
  	    break;
  
  	switch (opt) {
  	    case 'h':
  		usage();
  		break;
  
  	    case 'n':
  		logoname = optarg;
  		break;
  
  	    case 'o':
  		outputname = optarg;
  		break;
  
  	    case 't':
  		if (!strcmp(optarg, "mono"))
  		    logo_type = LINUX_LOGO_MONO;
  		else if (!strcmp(optarg, "vga16"))
  		    logo_type = LINUX_LOGO_VGA16;
  		else if (!strcmp(optarg, "clut224"))
  		    logo_type = LINUX_LOGO_CLUT224;
  		else if (!strcmp(optarg, "gray256"))
  		    logo_type = LINUX_LOGO_GRAY256;
  		else
  		    usage();
  		break;
  
  	    default:
  		usage();
  		break;
  	}
      }
      if (optind != argc-1)
  	usage();
  
      filename = argv[optind];
  
      read_image();
      switch (logo_type) {
  	case LINUX_LOGO_MONO:
  	    write_logo_mono();
  	    break;
  
  	case LINUX_LOGO_VGA16:
  	    write_logo_vga16();
  	    break;
  
  	case LINUX_LOGO_CLUT224:
  	    write_logo_clut224();
  	    break;
  
  	case LINUX_LOGO_GRAY256:
  	    write_logo_gray256();
  	    break;
      }
      exit(0);
  }