wrlib/ppm.c

   1 /* ppm.c - load PPM image from file
   2  *
   3  *  Raster graphics library
   4  *
   5  *  Copyright (c) 1997 Alfredo K. Kojima
   6  *
   7  *  This library is free software; you can redistribute it and/or
   8  *  modify it under the terms of the GNU Library General Public
   9  *  License as published by the Free Software Foundation; either
  10  *  version 2 of the License, or (at your option) any later version.
  11  *
  12  *  This library is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Library General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Library General Public
  18  *  License along with this library; if not, write to the Free
  19  *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <config.h>
  23
  24
  25 #include <X11/Xlib.h>
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29
  30 #include "wraster.h"
  31
  32
  33 static RImage*
  34 load_graymap(char *file_name, FILE *file, int w, int h, int max, int raw)
  35 {
  36     RImage *image;
  37
  38     image = RCreateImage(w, h, 0);
  39     if (!image) {
  40         return NULL;
  41     }
  42     if (!raw) {
  43
  44     } else {
  45         if (max<256) {
  46             if (!fgets(image->data[0], w*h, file))
  47                 goto short_file;
  48             memcpy(image->data[0], image->data[1], w*h);
  49             memcpy(image->data[0], image->data[2], w*h);
  50         } else {
  51
  52         }
  53     }
  54
  55     return image;
  56
  57   short_file:
  58     RErrorCode = RERR_BADIMAGEFILE;
  59     return NULL;
  60 }
  61
  62
  63 static RImage*
  64 load_pixmap(char *file_name, FILE *file, int w, int h, int max, int raw)
  65 {
  66     RImage *image;
  67     int i;
  68     char buf[3];
  69     char *r, *g, *b;
  70
  71     image = RCreateImage(w, h, 0);
  72     if (!image) {
  73         return NULL;
  74     }
  75     r = image->data[0];
  76     g = image->data[1];
  77     b = image->data[2];
  78     if (!raw) {
  79
  80     } else {
  81         if (max<256) {
  82             i = 0;
  83             while (i < w*h) {
  84                 if (fread(buf, 1, 3, file)!=3)
  85                     goto short_file;
  86                 *(r++) = buf[0];
  87                 *(g++) = buf[1];
  88                 *(b++) = buf[2];
  89                 i++;
  90             }
  91         } else {
  92
  93         }
  94     }
  95
  96     return image;
  97
  98   short_file:
  99     RErrorCode = RERR_BADIMAGEFILE;
 100     return NULL;
 101 }
 102
 103
 104 RImage*
 105 RLoadPPM(RContext *context, char *file_name, int index)
 106 {
 107     FILE *file;
 108     RImage *image = NULL;
 109     char buffer[256];
 110     int w, h, m;
 111     int type;
 112
 113 #define GETL() if (!fgets(buffer, 255, file)) goto short_file
 114
 115     file = fopen(file_name, "r");
 116     if (!file) {
 117         RErrorCode = RERR_OPEN;
 118         return NULL;
 119     }
 120
 121     /* get signature */
 122     GETL();
 123
 124     /* only accept raw pixmaps or graymaps */
 125     if (buffer[0] != 'P' || (buffer[1] != '5' && buffer[1] != '6')) {
 126         RErrorCode = RERR_BADFORMAT;
 127         fclose(file);
 128         return NULL;
 129     }
 130
 131     type = buffer[1];
 132
 133     /* skip comments */
 134     while (1) {
 135         GETL();
 136
 137         if (buffer[0]!='#')
 138             break;
 139     }
 140
 141     /* get size */
 142     if (sscanf(buffer, "%i %i", &w, &h)!=2)
 143         goto bad_file;
 144
 145
 146     GETL();
 147     if (sscanf(buffer, "%i", &m)!=1 || m < 1)
 148         goto bad_file;
 149
 150     if (type=='5')
 151         image = load_graymap(file_name, file, w, h, m, type=='5');
 152     else if (type=='6')
 153         image = load_pixmap(file_name, file, w, h, m, type=='6');
 154
 155     fclose(file);
 156     return image;
 157
 158   bad_file:
 159   short_file:
 160     RErrorCode = RERR_BADIMAGEFILE;
 161     fclose(file);
 162     return NULL;
 163 }
 164