wrlib/ppm.c

   1 /* ppm.c - load PPM image from file
   2  *
   3  * Raster graphics library
   4  *
   5  * Copyright (c) 1997-2003 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             unsigned char *ptr;
  47             char *buf;
  48             int x, y;
  49
  50             buf = malloc(w+1);
  51             if (!buf) {
  52                 return NULL;
  53             }
  54
  55             ptr = image->data;
  56             for (y = 0; y < h; y++) {
  57                 if (!fread(buf, w, 1, file)) {
  58                     free(buf);
  59                     goto short_file;
  60                 }
  61                 for (x = 0; x < w; x++) {
  62                     *(ptr++) = buf[x];
  63                     *(ptr++) = buf[x];
  64                     *(ptr++) = buf[x];
  65                 }
  66             }
  67             free(buf);
  68         } else {
  69
  70         }
  71     }
  72
  73     return image;
  74
  75 short_file:
  76     RErrorCode = RERR_BADIMAGEFILE;
  77     return NULL;
  78 }
  79
  80
  81 static RImage*
  82 load_pixmap(char *file_name, FILE *file, int w, int h, int max, int raw)
  83 {
  84     RImage *image;
  85     int i;
  86     char buf[3];
  87     unsigned char *ptr;
  88
  89     image = RCreateImage(w, h, 0);
  90     if (!image) {
  91         return NULL;
  92     }
  93     ptr = image->data;
  94     if (!raw) {
  95
  96     } else {
  97         if (max<256) {
  98             i = 0;
  99             while (i < w*h) {
 100                 if (fread(buf, 1, 3, file)!=3)
 101                     goto short_file;
 102                 *(ptr++) = buf[0];
 103                 *(ptr++) = buf[1];
 104                 *(ptr++) = buf[2];
 105                 i++;
 106             }
 107         } else {
 108
 109         }
 110     }
 111
 112     return image;
 113
 114 short_file:
 115     RErrorCode = RERR_BADIMAGEFILE;
 116     return NULL;
 117 }
 118
 119
 120 RImage*
 121 RLoadPPM(RContext *context, char *file_name, int index)
 122 {
 123     FILE *file;
 124     RImage *image = NULL;
 125     char buffer[256];
 126     int w, h, m;
 127     int type;
 128
 129 #define GETL() if (!fgets(buffer, 255, file)) goto short_file
 130
 131     file = fopen(file_name, "rb");
 132     if (!file) {
 133         RErrorCode = RERR_OPEN;
 134         return NULL;
 135     }
 136
 137     /* get signature */
 138     GETL();
 139
 140     /* only accept raw pixmaps or graymaps */
 141     if (buffer[0] != 'P' || (buffer[1] != '5' && buffer[1] != '6')) {
 142         RErrorCode = RERR_BADFORMAT;
 143         fclose(file);
 144         return NULL;
 145     }
 146
 147     type = buffer[1];
 148
 149     /* skip comments */
 150     while (1) {
 151         GETL();
 152
 153         if (buffer[0]!='#')
 154             break;
 155     }
 156
 157     /* get size */
 158     if (sscanf(buffer, "%i %i", &w, &h)!=2 || w < 1 || h < 1)
 159         goto bad_file;
 160
 161
 162     GETL();
 163     if (sscanf(buffer, "%i", &m)!=1 || m < 1)
 164         goto bad_file;
 165
 166     if (type=='5')
 167         image = load_graymap(file_name, file, w, h, m, type=='5');
 168     else if (type=='6')
 169         image = load_pixmap(file_name, file, w, h, m, type=='6');
 170
 171     fclose(file);
 172     return image;
 173
 174 bad_file:
 175 short_file:
 176     RErrorCode = RERR_BADIMAGEFILE;
 177     fclose(file);
 178     return NULL;
 179 }
 180