tumble: tumble_png.c@2fae6df568f6 (annotated)

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tumble_png.c@2fae6df568f6 (annotated)

tumble_png.c

Mon, 14 Dec 2009 16:18:21 +0000

author: Philip Pemberton <philpem@philpem.me.uk>
date: Mon, 14 Dec 2009 16:18:21 +0000
changeset 172: 2fae6df568f6
parent 166: 301f6f17c364
permissions: -rw-r--r--

remove erroneous 0.33-philpem1 tag

 /*
  * tumble: build a PDF file from image files
  *
  * Copyright 2004 Daniel Gloeckner
  *
  * Derived from tumble_jpeg.c written 2003 by Eric Smith <eric at brouhaha.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.  Note that permission is
  * not granted to redistribute this program under the terms of any
  * other version of the General Public License.
  *
  * 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 USA
  */
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <strings.h>  /* strcasecmp() is a BSDism */
 #include "semantics.h"
 #include "tumble.h"
 #include "bitblt.h"
 #include "pdf.h"
 #include "tumble_input.h"
 static FILE *png_f;
 static struct {
   uint32_t palent;
   uint8_t bpp;
   uint8_t color;
   char pal[256*3];
 } cinfo;
 static bool match_png_suffix (char *suffix)
 {
   return (strcasecmp (suffix, ".png") == 0);
 }
 static bool close_png_input_file (void)
 {
   return (1);
 }
 #define BENUM(p) (((p)[0]<<24)+((p)[1]<<16)+((p)[2]<<8)+(p)[3])
 static bool open_png_input_file (FILE *f, char *name)
 {
   const char sig [8]="\211PNG\r\n\032\n";
   uint8_t buf [8];
   int l;
   l = fread (buf, 1, sizeof (sig), f);
   if (l != sizeof (sig) || memcmp(buf,sig,sizeof(sig))) {
     rewind(f);
     return 0;
   }
   png_f = f;
   return 1;
 }
 static bool last_png_input_page (void)
 {
   return 1;
 }
 static bool get_png_image_info (int image,
 				 input_attributes_t input_attributes,
 				 image_info_t *image_info)
 {
   uint8_t buf [20], unit;
   uint32_t width,height,xppu,yppu;
   size_t l;
   bool seen_IHDR,seen_PLTE,seen_pHYs;
   seen_IHDR=seen_PLTE=seen_pHYs=false;
   memset(&cinfo,0,sizeof(cinfo));
   unit=0;
   xppu=yppu=1;
   for(;;)
   {
     l = fread (buf, 1, 8, png_f);
     if(l != 8)
       return 0;
     l=BENUM(buf);
     if(!memcmp(buf+4,"IHDR",4)) {
       if(seen_IHDR || l!=13)
 	return 0;
       seen_IHDR=true;
       l = fread (buf, 1, 17, png_f);
       if(l!=17)
 	return 0;
       width=BENUM(buf);
       height=BENUM(buf+4);
       cinfo.bpp=buf[8];
       cinfo.color=buf[9];
       if(buf[8]>8 || buf[10] || buf[11] || buf[12])
 	return 0;
       continue;
     }
     if(!seen_IHDR)
       return 0;
     if(!memcmp(buf+4,"PLTE",4)) {
       size_t i;
       if(seen_PLTE || l>256*3 || l%3 || !cinfo.color)
 	return 0;
       seen_PLTE=true;
       i = fread (cinfo.pal, 1, l, png_f);
       if(i != l)
 	return 0;
       cinfo.palent=l/3;
       fseek(png_f,4,SEEK_CUR);
     } else if(!memcmp(buf+4,"pHYs",4)) {
       if(seen_pHYs || l!=9)
 	return 0;
       seen_pHYs=true;
       l = fread (buf, 1, 13, png_f);
       if(l != 13)
 	return 0;
       xppu=BENUM(buf);
       yppu=BENUM(buf+4);
       unit=buf[8];
     } else if(!memcmp(buf+4,"IDAT",4)) {
       fseek(png_f,-8,SEEK_CUR);
       break;
     } else {
       fseek(png_f,l+4,SEEK_CUR);
     }
   }
   if(cinfo.color==3 && !seen_PLTE)
     return 0;
 #ifdef DEBUG_JPEG
   printf ("color type: %d\n", cinfo.color);
   printf ("bit depth: %d\n", cinfo.bpp);
   printf ("density unit: %d\n", unit);
   printf ("x density: %d\n", xppu);
   printf ("y density: %d\n", yppu);
   printf ("width: %d\n", width);
   printf ("height: %d\n", height);
 #endif
   switch (cinfo.color)
     {
     case 0:
       image_info->color = 0;
       break;
     case 2:
     case 3:
       image_info->color = 1;
       break;
     default:
       fprintf (stderr, "PNG color type %d not supported\n", cinfo.color);
       return (0);
     }
   image_info->width_samples = width;
   image_info->height_samples = height;
   switch (unit==1)
   {
     case 1:
       image_info->width_points = ((image_info->width_samples * POINTS_PER_INCH) /
 				  (xppu * 0.0254));
       image_info->height_points = ((image_info->height_samples * POINTS_PER_INCH) /
 				   (yppu * 0.0254));
       break;
     case 0:
       /* assume 300 DPI - not great, but what else can we do? */
       image_info->width_points = (image_info->width_samples * POINTS_PER_INCH) / 300.0;
       image_info->height_points = ((double) yppu * image_info->height_samples * POINTS_PER_INCH) / ( 300.0 * xppu);
       break;
     default:
       fprintf (stderr, "PNG pHYs unit %d not supported\n", unit);
   }
   return 1;
 }
 static bool process_png_image (int image,  /* range 1 .. n */
 				input_attributes_t input_attributes,
 				image_info_t *image_info,
 				pdf_page_handle page)
 {
   pdf_write_png_image (page,
 , 0,  /* x, y */
 			image_info->width_points,
 			image_info->height_points,
 			cinfo.color,
 			cinfo.color==3?cinfo.pal:NULL,
 			cinfo.palent,
 			cinfo.bpp,
 			image_info->width_samples,
 			image_info->height_samples,
 			png_f);
   return (1);
 }
 input_handler_t png_handler =
   {
     match_png_suffix,
     open_png_input_file,
     close_png_input_file,
     last_png_input_page,
     get_png_image_info,
     process_png_image
   };
 void init_png_handler (void)
 {
   install_input_handler (& png_handler);
 }

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tumble_png.c@2fae6df568f6 (annotated)

tumble_png.c