/*

 *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file

 *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>

 *

 *  version 1.0 - 1999.10.15 - First version.

 *  version 1.1 - 2015.07.29 - Fixed leaks (Glenn Randers-Pehrson)

 *

 *  Permission to use, copy, modify, and distribute this software and

 *  its documentation for any purpose and without fee is hereby granted,

 *  provided that the above copyright notice appear in all copies and

 *  that both that copyright notice and this permission notice appear in

 *  supporting documentation. This software is provided "as is" without

 *  express or implied warranty.

 */

#include <stdio.h>

#include <stdlib.h>

#ifdef __TURBOC__

#include <mem.h>

#include <fcntl.h>

#endif

#include <zlib.h>

#ifndef BOOL

#define BOOL unsigned char

#endif

#ifndef TRUE

#define TRUE (BOOL) 1

#endif

#ifndef FALSE

#define FALSE (BOOL) 0

#endif

#define STDIN  0

#define STDOUT 1

#define STDERR 2

/* to make pnm2png verbose so we can find problems (needs to be before png.h) */

#ifndef PNG_DEBUG

#define PNG_DEBUG 0

#endif

#include "png.h"

/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */

#ifndef png_jmpbuf

#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)

#endif

/* function prototypes */

int  main (int argc, char *argv[]);

void usage ();

BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,

    BOOL alpha);

void get_token(FILE *pnm_file, char *token);

png_uint_32 get_data (FILE *pnm_file, int depth);

png_uint_32 get_value (FILE *pnm_file, int depth);

/*

 *  main

 */

int main(int argc, char *argv[])

{

  FILE *fp_rd = stdin;

  FILE *fp_al = NULL;

  FILE *fp_wr = stdout;

  BOOL interlace = FALSE;

  BOOL alpha = FALSE;

  int argi;

  for (argi = 1; argi < argc; argi++)

  {

    if (argv[argi][0] == '-')

    {

      switch (argv[argi][1])

      {

        case 'i':

          interlace = TRUE;

          break;

        case 'a':

          alpha = TRUE;

          argi++;

          if ((fp_al = fopen (argv[argi], "rb")) == NULL)

          {

            fprintf (stderr, "PNM2PNG\n");

            fprintf (stderr, "Error:  alpha-channel file %s does not exist\n",

               argv[argi]);

            exit (1);

          }

          break;

        case 'h':

        case '?':

          usage();

          exit(0);

          break;

        default:

          fprintf (stderr, "PNM2PNG\n");

          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);

          usage();

          exit(1);

          break;

      } /* end switch */

    }

    else if (fp_rd == stdin)

    {

      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)

      {

        fprintf (stderr, "PNM2PNG\n");

        fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);

        exit (1);

      }

    }

    else if (fp_wr == stdout)

    {

      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)

      {

        fprintf (stderr, "PNM2PNG\n");

        fprintf (stderr, "Error:  can not create PNG-file %s\n", argv[argi]);

        exit (1);

      }

    }

    else

    {

      fprintf (stderr, "PNM2PNG\n");

      fprintf (stderr, "Error:  too many parameters\n");

      usage();

      exit (1);

    }

  } /* end for */

#ifdef __TURBOC__

  /* set stdin/stdout to binary, we're reading the PNM always! in binary format */

  if (fp_rd == stdin)

  {

    setmode (STDIN, O_BINARY);

  }

  if (fp_wr == stdout)

  {

    setmode (STDOUT, O_BINARY);

  }

#endif

  /* call the conversion program itself */

  if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)

  {

    fprintf (stderr, "PNM2PNG\n");

    fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");

    exit (1);

  }

  /* close input file */

  fclose (fp_rd);

  /* close output file */

  fclose (fp_wr);

  /* close alpha file */

  if (alpha)

    fclose (fp_al);

  return 0;

}

/*

 *  usage

 */

void usage()

{

  fprintf (stderr, "PNM2PNG\n");

  fprintf (stderr, "   by Willem van Schaik, 1999\n");

#ifdef __TURBOC__

  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");

#else

  fprintf (stderr, "   for Linux (and Unix) compilers\n");

#endif

  fprintf (stderr, "Usage:  pnm2png [options] <file>.<pnm> [<file>.png]\n");

  fprintf (stderr, "   or:  ... | pnm2png [options]\n");

  fprintf (stderr, "Options:\n");

  fprintf (stderr, "   -i[nterlace]   write png-file with interlacing on\n");

  fprintf (stderr,

      "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");

  fprintf (stderr, "   -h | -?  print this help-information\n");

}

/*

 *  pnm2png

 */

BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,

     BOOL alpha)

{

  png_struct    *png_ptr = NULL;

  png_info      *info_ptr = NULL;

  png_byte      *png_pixels = NULL;

  png_byte      **row_pointers = NULL;

  png_byte      *pix_ptr = NULL;

  volatile png_uint_32   row_bytes;

  char          type_token[16];

  char          width_token[16];

  char          height_token[16];

  char          maxval_token[16];

  volatile int    color_type=1;

  unsigned long   ul_width=0, ul_alpha_width=0;

  unsigned long   ul_height=0, ul_alpha_height=0;

  unsigned long   ul_maxval=0;

  volatile png_uint_32   width=0, height=0;

  volatile png_uint_32   alpha_width=0, alpha_height=0;

  png_uint_32   maxval;

  volatile int           bit_depth = 0;

  int           channels=0;

  int           alpha_depth = 0;

  int           alpha_present=0;

  int           row, col;

  BOOL          raw, alpha_raw = FALSE;

#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)

  BOOL          packed_bitmap = FALSE;

#endif

  png_uint_32   tmp16;

  int           i;

  /* read header of PNM file */

  get_token(pnm_file, type_token);

  if (type_token[0] != 'P')

  {

    return FALSE;

  }

  else if ((type_token[1] == '1') || (type_token[1] == '4'))

  {

#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)

    raw = (type_token[1] == '4');

    color_type = PNG_COLOR_TYPE_GRAY;

    get_token(pnm_file, width_token);

    sscanf (width_token, "%lu", &ul_width);

    width = (png_uint_32) ul_width;

    get_token(pnm_file, height_token);

    sscanf (height_token, "%lu", &ul_height);

    height = (png_uint_32) ul_height;

    bit_depth = 1;

    packed_bitmap = TRUE;

#else

    fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and \n");

    fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");

#endif

  }

  else if ((type_token[1] == '2') || (type_token[1] == '5'))

  {

    raw = (type_token[1] == '5');

    color_type = PNG_COLOR_TYPE_GRAY;

    get_token(pnm_file, width_token);

    sscanf (width_token, "%lu", &ul_width);

    width = (png_uint_32) ul_width;

    get_token(pnm_file, height_token);

    sscanf (height_token, "%lu", &ul_height);

    height = (png_uint_32) ul_height;

    get_token(pnm_file, maxval_token);

    sscanf (maxval_token, "%lu", &ul_maxval);

    maxval = (png_uint_32) ul_maxval;

    if (maxval <= 1)

      bit_depth = 1;

    else if (maxval <= 3)

      bit_depth = 2;

    else if (maxval <= 15)

      bit_depth = 4;

    else if (maxval <= 255)

      bit_depth = 8;

    else /* if (maxval <= 65535) */

      bit_depth = 16;

  }

  else if ((type_token[1] == '3') || (type_token[1] == '6'))

  {

    raw = (type_token[1] == '6');

    color_type = PNG_COLOR_TYPE_RGB;

    get_token(pnm_file, width_token);

    sscanf (width_token, "%lu", &ul_width);

    width = (png_uint_32) ul_width;

    get_token(pnm_file, height_token);

    sscanf (height_token, "%lu", &ul_height);

    height = (png_uint_32) ul_height;

    get_token(pnm_file, maxval_token);

    sscanf (maxval_token, "%lu", &ul_maxval);

    maxval = (png_uint_32) ul_maxval;

    if (maxval <= 1)

      bit_depth = 1;

    else if (maxval <= 3)

      bit_depth = 2;

    else if (maxval <= 15)

      bit_depth = 4;

    else if (maxval <= 255)

      bit_depth = 8;

    else /* if (maxval <= 65535) */

      bit_depth = 16;

  }

  else

  {

    return FALSE;

  }

  /* read header of PGM file with alpha channel */

  if (alpha)

  {

    if (color_type == PNG_COLOR_TYPE_GRAY)

      color_type = PNG_COLOR_TYPE_GRAY_ALPHA;

    if (color_type == PNG_COLOR_TYPE_RGB)

      color_type = PNG_COLOR_TYPE_RGB_ALPHA;

    get_token(alpha_file, type_token);

    if (type_token[0] != 'P')

    {

      return FALSE;

    }

    else if ((type_token[1] == '2') || (type_token[1] == '5'))

    {

      alpha_raw = (type_token[1] == '5');

      get_token(alpha_file, width_token);

      sscanf (width_token, "%lu", &ul_alpha_width);

      alpha_width=(png_uint_32) ul_alpha_width;

      if (alpha_width != width)

        return FALSE;

      get_token(alpha_file, height_token);

      sscanf (height_token, "%lu", &ul_alpha_height);

      alpha_height = (png_uint_32) ul_alpha_height;

      if (alpha_height != height)

        return FALSE;

      get_token(alpha_file, maxval_token);

      sscanf (maxval_token, "%lu", &ul_maxval);

      maxval = (png_uint_32) ul_maxval;

      if (maxval <= 1)

        alpha_depth = 1;

      else if (maxval <= 3)

        alpha_depth = 2;

      else if (maxval <= 15)

        alpha_depth = 4;

      else if (maxval <= 255)

        alpha_depth = 8;

      else /* if (maxval <= 65535) */

        alpha_depth = 16;

      if (alpha_depth != bit_depth)

        return FALSE;

    }

    else

    {

      return FALSE;

    }

  } /* end if alpha */

  /* calculate the number of channels and store alpha-presence */

  if (color_type == PNG_COLOR_TYPE_GRAY)

    channels = 1;

  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)

    channels = 2;

  else if (color_type == PNG_COLOR_TYPE_RGB)

    channels = 3;

  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)

    channels = 4;

#if 0

  else

    channels = 0; /* cannot happen */

#endif

  alpha_present = (channels - 1) % 2;

#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)

  if (packed_bitmap)

    /* row data is as many bytes as can fit width x channels x bit_depth */

    row_bytes = (width * channels * bit_depth + 7) / 8;

  else

#endif

    /* row_bytes is the width x number of channels x (bit-depth / 8) */

    row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);

  if ((png_pixels = (png_byte *)

     malloc (row_bytes * height * sizeof (png_byte))) == NULL)

    return FALSE;

  /* read data from PNM file */

  pix_ptr = png_pixels;

  for (row = 0; row < (int) height; row++)

  {

#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)

    if (packed_bitmap) {

      for (i = 0; i < (int) row_bytes; i++)

        /* png supports this format natively so no conversion is needed */

        *pix_ptr++ = get_data (pnm_file, 8);

    } else

#endif

    {

      for (col = 0; col < (int) width; col++)

      {

        for (i = 0; i < (channels - alpha_present); i++)

        {

          if (raw)

            *pix_ptr++ = get_data (pnm_file, bit_depth);

          else

            if (bit_depth <= 8)

              *pix_ptr++ = get_value (pnm_file, bit_depth);

            else

            {

              tmp16 = get_value (pnm_file, bit_depth);

              *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);

              pix_ptr++;

              *pix_ptr = (png_byte) (tmp16 & 0xFF);

              pix_ptr++;

            }

        }

        if (alpha) /* read alpha-channel from pgm file */

        {

          if (alpha_raw)

            *pix_ptr++ = get_data (alpha_file, alpha_depth);

          else

            if (alpha_depth <= 8)

              *pix_ptr++ = get_value (alpha_file, bit_depth);

            else

            {

              tmp16 = get_value (alpha_file, bit_depth);

              *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);

              *pix_ptr++ = (png_byte) (tmp16 & 0xFF);

            }

        } /* if alpha */

      } /* if packed_bitmap */

    } /* end for col */

  } /* end for row */

  /* prepare the standard PNG structures */

  png_ptr = png_create_write_struct (png_get_libpng_ver(NULL), NULL, NULL,

      NULL);

  if (!png_ptr)

  {

    free (png_pixels);

    png_pixels = NULL;

    return FALSE;

  }

  info_ptr = png_create_info_struct (png_ptr);

  if (!info_ptr)

  {

    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);

    free (png_pixels);

    png_pixels = NULL;

    return FALSE;

  }

#if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)

  if (packed_bitmap == TRUE)

  {

    png_set_packing (png_ptr);

    png_set_invert_mono (png_ptr);

  }

#endif

  /* setjmp() must be called in every function that calls a PNG-reading libpng function */

  if (setjmp (png_jmpbuf(png_ptr)))

  {

    png_destroy_write_struct (&png_ptr, &info_ptr);

    free (png_pixels);

    png_pixels = NULL;

    return FALSE;

  }

  /* initialize the png structure */

  png_init_io (png_ptr, png_file);

  /* we're going to write more or less the same PNG as the input file */

  png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,

    (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,

    PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);

  /* write the file header information */

  png_write_info (png_ptr, info_ptr);

  /* if needed we will allocate memory for an new array of row-pointers */

  if (row_pointers == (unsigned char**) NULL)

  {

    if ((row_pointers = (png_byte **)

        malloc (height * sizeof (png_bytep))) == NULL)

    {

      png_destroy_write_struct (&png_ptr, &info_ptr);

      free (png_pixels);

      png_pixels = NULL;

      return FALSE;

    }

  }

  /* set the individual row_pointers to point at the correct offsets */

  for (i = 0; i < (int) height; i++)

    row_pointers[i] = png_pixels + i * row_bytes;

  /* write out the entire image data in one call */

  png_write_image (png_ptr, row_pointers);

  /* write the additional chunks to the PNG file (not really needed) */

  png_write_end (png_ptr, info_ptr);

  /* clean up after the write, and free any memory allocated */

  png_destroy_write_struct (&png_ptr, &info_ptr);

  if (row_pointers != (unsigned char**) NULL)

    free (row_pointers);

  if (png_pixels != (unsigned char*) NULL)

    free (png_pixels);

  return TRUE;

} /* end of pnm2png */

/*

 * get_token() - gets the first string after whitespace

 */

void get_token(FILE *pnm_file, char *token)

{

  int i = 0;

  int ret;

  /* remove white-space and comment lines */

  do

  {

    ret = fgetc(pnm_file);

    if (ret == '#') {

      /* the rest of this line is a comment */

      do

      {

        ret = fgetc(pnm_file);

      }

      while ((ret != '\n') && (ret != '\r') && (ret != EOF));

    }

    if (ret == EOF) break;

    token[i] = (unsigned char) ret;

  }

  while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));

  /* read string */

  do

  {

    ret = fgetc(pnm_file);

    if (ret == EOF) break;

    i++;

    token[i] = (unsigned char) ret;

  }

  while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));

  token[i] = '\0';

  return;

}

/*

 * get_data() - takes first byte and converts into next pixel value,

 *        taking as much bits as defined by bit-depth and

 *        using the bit-depth to fill up a byte (0Ah -> AAh)

 */

png_uint_32 get_data (FILE *pnm_file, int depth)

{

  static int bits_left = 0;

  static int old_value = 0;

  static int mask = 0;

  int i;

  png_uint_32 ret_value;

  if (mask == 0)

    for (i = 0; i < depth; i++)

      mask = (mask >> 1) | 0x80;

  if (bits_left <= 0)

  {

    old_value = fgetc (pnm_file);

    bits_left = 8;

  }

  ret_value = old_value & mask;

  for (i = 1; i < (8 / depth); i++)

    ret_value = ret_value || (ret_value >> depth);

  old_value = (old_value << depth) & 0xFF;

  bits_left -= depth;

  return ret_value;

}

/*

 * get_value() - takes first (numeric) string and converts into number,

 *         using the bit-depth to fill up a byte (0Ah -> AAh)

 */

png_uint_32 get_value (FILE *pnm_file, int depth)

{

  static png_uint_32 mask = 0;

  png_byte token[16];

  unsigned long ul_ret_value;

  png_uint_32 ret_value;

  int i = 0;

  if (mask == 0)

    for (i = 0; i < depth; i++)

      mask = (mask << 1) | 0x01;

  get_token (pnm_file, (char *) token);

  sscanf ((const char *) token, "%lu", &ul_ret_value);

  ret_value = (png_uint_32) ul_ret_value;

  ret_value &= mask;

  if (depth < 8)

    for (i = 0; i < (8 / depth); i++)

      ret_value = (ret_value << depth) || ret_value;

  return ret_value;

}

/* end of source */