tumble_png.c

changeset 166
301f6f17c364
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/tumble_png.c	Mon Dec 14 15:51:53 2009 +0000
     1.3 @@ -0,0 +1,233 @@
     1.4 +/*
     1.5 + * tumble: build a PDF file from image files
     1.6 + *
     1.7 + * Copyright 2004 Daniel Gloeckner
     1.8 + * 
     1.9 + * Derived from tumble_jpeg.c written 2003 by Eric Smith <eric at brouhaha.com>
    1.10 + *
    1.11 + * This program is free software; you can redistribute it and/or modify
    1.12 + * it under the terms of the GNU General Public License version 2 as
    1.13 + * published by the Free Software Foundation.  Note that permission is
    1.14 + * not granted to redistribute this program under the terms of any
    1.15 + * other version of the General Public License.
    1.16 + *
    1.17 + * This program is distributed in the hope that it will be useful,
    1.18 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.19 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.20 + * GNU General Public License for more details.
    1.21 + *
    1.22 + * You should have received a copy of the GNU General Public License
    1.23 + * along with this program; if not, write to the Free Software
    1.24 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA
    1.25 + */
    1.26 +
    1.27 +
    1.28 +#include <stdbool.h>
    1.29 +#include <stdint.h>
    1.30 +#include <stdio.h>
    1.31 +#include <strings.h>  /* strcasecmp() is a BSDism */
    1.32 +
    1.33 +
    1.34 +#include "semantics.h"
    1.35 +#include "tumble.h"
    1.36 +#include "bitblt.h"
    1.37 +#include "pdf.h"
    1.38 +#include "tumble_input.h"
    1.39 +
    1.40 +
    1.41 +static FILE *png_f;
    1.42 +
    1.43 +static struct {
    1.44 +  uint32_t palent;
    1.45 +  uint8_t bpp;
    1.46 +  uint8_t color;
    1.47 +  char pal[256*3];
    1.48 +} cinfo;
    1.49 +
    1.50 +
    1.51 +static bool match_png_suffix (char *suffix)
    1.52 +{
    1.53 +  return (strcasecmp (suffix, ".png") == 0);
    1.54 +}
    1.55 +
    1.56 +static bool close_png_input_file (void)
    1.57 +{
    1.58 +  return (1);
    1.59 +}
    1.60 +
    1.61 +#define BENUM(p) (((p)[0]<<24)+((p)[1]<<16)+((p)[2]<<8)+(p)[3])
    1.62 +
    1.63 +static bool open_png_input_file (FILE *f, char *name)
    1.64 +{
    1.65 +  const char sig [8]="\211PNG\r\n\032\n";
    1.66 +  uint8_t buf [8];
    1.67 +  int l;
    1.68 +
    1.69 +  l = fread (buf, 1, sizeof (sig), f);
    1.70 +  if (l != sizeof (sig) || memcmp(buf,sig,sizeof(sig))) {
    1.71 +    rewind(f);
    1.72 +    return 0;
    1.73 +  }
    1.74 +
    1.75 +  png_f = f;
    1.76 +  
    1.77 +  return 1;
    1.78 +}
    1.79 +
    1.80 +
    1.81 +static bool last_png_input_page (void)
    1.82 +{
    1.83 +  return 1;
    1.84 +}
    1.85 +
    1.86 +
    1.87 +static bool get_png_image_info (int image,
    1.88 +				 input_attributes_t input_attributes,
    1.89 +				 image_info_t *image_info)
    1.90 +{
    1.91 +  uint8_t buf [20], unit;
    1.92 +  uint32_t width,height,xppu,yppu;
    1.93 +  size_t l;
    1.94 +  bool seen_IHDR,seen_PLTE,seen_pHYs;
    1.95 +
    1.96 +  seen_IHDR=seen_PLTE=seen_pHYs=false;
    1.97 +  memset(&cinfo,0,sizeof(cinfo));
    1.98 +  unit=0;
    1.99 +  xppu=yppu=1;
   1.100 +  
   1.101 +  for(;;)
   1.102 +  {
   1.103 +    l = fread (buf, 1, 8, png_f);
   1.104 +    if(l != 8)
   1.105 +      return 0;
   1.106 +    l=BENUM(buf);
   1.107 +    if(!memcmp(buf+4,"IHDR",4)) {
   1.108 +      if(seen_IHDR || l!=13)
   1.109 +	return 0;
   1.110 +      seen_IHDR=true;
   1.111 +      l = fread (buf, 1, 17, png_f);
   1.112 +      if(l!=17)
   1.113 +	return 0;
   1.114 +      width=BENUM(buf);
   1.115 +      height=BENUM(buf+4);
   1.116 +      cinfo.bpp=buf[8];
   1.117 +      cinfo.color=buf[9];
   1.118 +      if(buf[8]>8 || buf[10] || buf[11] || buf[12])
   1.119 +	return 0;
   1.120 +      continue;
   1.121 +    }
   1.122 +    if(!seen_IHDR)
   1.123 +      return 0;
   1.124 +    if(!memcmp(buf+4,"PLTE",4)) {
   1.125 +      size_t i;
   1.126 +      if(seen_PLTE || l>256*3 || l%3 || !cinfo.color)
   1.127 +	return 0;
   1.128 +      seen_PLTE=true;
   1.129 +      i = fread (cinfo.pal, 1, l, png_f);
   1.130 +      if(i != l)
   1.131 +	return 0;
   1.132 +      cinfo.palent=l/3;
   1.133 +      fseek(png_f,4,SEEK_CUR);
   1.134 +    } else if(!memcmp(buf+4,"pHYs",4)) {
   1.135 +      if(seen_pHYs || l!=9)
   1.136 +	return 0;
   1.137 +      seen_pHYs=true;
   1.138 +      l = fread (buf, 1, 13, png_f);
   1.139 +      if(l != 13)
   1.140 +	return 0;
   1.141 +      xppu=BENUM(buf);
   1.142 +      yppu=BENUM(buf+4);
   1.143 +      unit=buf[8];
   1.144 +    } else if(!memcmp(buf+4,"IDAT",4)) {
   1.145 +      fseek(png_f,-8,SEEK_CUR);
   1.146 +      break;
   1.147 +    } else {
   1.148 +      fseek(png_f,l+4,SEEK_CUR);
   1.149 +    }
   1.150 +  }
   1.151 +  if(cinfo.color==3 && !seen_PLTE)
   1.152 +    return 0;
   1.153 +
   1.154 +#ifdef DEBUG_JPEG
   1.155 +  printf ("color type: %d\n", cinfo.color);
   1.156 +  printf ("bit depth: %d\n", cinfo.bpp);
   1.157 +  printf ("density unit: %d\n", unit);
   1.158 +  printf ("x density: %d\n", xppu);
   1.159 +  printf ("y density: %d\n", yppu);
   1.160 +  printf ("width: %d\n", width);
   1.161 +  printf ("height: %d\n", height);
   1.162 +#endif
   1.163 +
   1.164 +  switch (cinfo.color)
   1.165 +    {
   1.166 +    case 0:
   1.167 +      image_info->color = 0;
   1.168 +      break;
   1.169 +    case 2:
   1.170 +    case 3:
   1.171 +      image_info->color = 1;
   1.172 +      break;
   1.173 +    default:
   1.174 +      fprintf (stderr, "PNG color type %d not supported\n", cinfo.color);
   1.175 +      return (0);
   1.176 +    }
   1.177 +  image_info->width_samples = width;
   1.178 +  image_info->height_samples = height;
   1.179 +
   1.180 +  switch (unit==1)
   1.181 +  {
   1.182 +    case 1:
   1.183 +      image_info->width_points = ((image_info->width_samples * POINTS_PER_INCH) /
   1.184 +				  (xppu * 0.0254));
   1.185 +      image_info->height_points = ((image_info->height_samples * POINTS_PER_INCH) /
   1.186 +				   (yppu * 0.0254));
   1.187 +      break;
   1.188 +    case 0:
   1.189 +      /* assume 300 DPI - not great, but what else can we do? */
   1.190 +      image_info->width_points = (image_info->width_samples * POINTS_PER_INCH) / 300.0;
   1.191 +      image_info->height_points = ((double) yppu * image_info->height_samples * POINTS_PER_INCH) / ( 300.0 * xppu);
   1.192 +      break;
   1.193 +    default:
   1.194 +      fprintf (stderr, "PNG pHYs unit %d not supported\n", unit);
   1.195 +  }
   1.196 +
   1.197 +  return 1;
   1.198 +}
   1.199 +
   1.200 +
   1.201 +static bool process_png_image (int image,  /* range 1 .. n */
   1.202 +				input_attributes_t input_attributes,
   1.203 +				image_info_t *image_info,
   1.204 +				pdf_page_handle page)
   1.205 +{
   1.206 +  pdf_write_png_image (page,
   1.207 +			0, 0,  /* x, y */
   1.208 +			image_info->width_points,
   1.209 +			image_info->height_points,
   1.210 +			cinfo.color,
   1.211 +			cinfo.color==3?cinfo.pal:NULL,
   1.212 +			cinfo.palent,
   1.213 +			cinfo.bpp,
   1.214 +			image_info->width_samples,
   1.215 +			image_info->height_samples,
   1.216 +			png_f);
   1.217 +
   1.218 +  return (1);
   1.219 +}
   1.220 +
   1.221 +
   1.222 +input_handler_t png_handler =
   1.223 +  {
   1.224 +    match_png_suffix,
   1.225 +    open_png_input_file,
   1.226 +    close_png_input_file,
   1.227 +    last_png_input_page,
   1.228 +    get_png_image_info,
   1.229 +    process_png_image
   1.230 +  };
   1.231 +
   1.232 +
   1.233 +void init_png_handler (void)
   1.234 +{
   1.235 +  install_input_handler (& png_handler);
   1.236 +}