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., 51 Franklin St, Fifth Floor, Boston,
  20  *  MA 02110-1301, USA.
  21  */
  22
  23 #include <config.h>
  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 static RImage *load_graymap(FILE * file, int w, int h, int max, int raw)
  33 {
  34         RImage *image;
  35
  36         image = RCreateImage(w, h, 0);
  37         if (!image) {
  38                 return NULL;
  39         }
  40         if (!raw) {
  41
  42         } else {
  43                 if (max < 256) {
  44                         unsigned char *ptr;
  45                         char *buf;
  46                         int x, y;
  47
  48                         buf = malloc(w + 1);
  49                         if (!buf) {
  50                                 return NULL;
  51                         }
  52
  53                         ptr = image->data;
  54                         for (y = 0; y < h; y++) {
  55                                 if (!fread(buf, w, 1, file)) {
  56                                         free(buf);
  57                                         goto short_file;
  58                                 }
  59                                 for (x = 0; x < w; x++) {
  60                                         *(ptr++) = buf[x];
  61                                         *(ptr++) = buf[x];
  62                                         *(ptr++) = buf[x];
  63                                 }
  64                         }
  65                         free(buf);
  66                 } else {
  67
  68                 }
  69         }
  70
  71         return image;
  72
  73  short_file:
  74         RErrorCode = RERR_BADIMAGEFILE;
  75         return NULL;
  76 }
  77
  78 static RImage *load_pixmap(FILE * file, int w, int h, int max, int raw)
  79 {
  80         RImage *image;
  81         int i;
  82         char buf[3];
  83         unsigned char *ptr;
  84
  85         image = RCreateImage(w, h, 0);
  86         if (!image) {
  87                 return NULL;
  88         }
  89         ptr = image->data;
  90         if (!raw) {
  91
  92         } else {
  93                 if (max < 256) {
  94                         i = 0;
  95                         while (i < w * h) {
  96                                 if (fread(buf, 1, 3, file) != 3)
  97                                         goto short_file;
  98                                 *(ptr++) = buf[0];
  99                                 *(ptr++) = buf[1];
 100                                 *(ptr++) = buf[2];
 101                                 i++;
 102                         }
 103                 } else {
 104
 105                 }
 106         }
 107
 108         return image;
 109
 110  short_file:
 111         RErrorCode = RERR_BADIMAGEFILE;
 112         return NULL;
 113 }
 114
 115 RImage *RLoadPPM(char *file_name)
 116 {
 117         FILE *file;
 118         RImage *image = NULL;
 119         char buffer[256];
 120         int w, h, m;
 121         int type;
 122
 123 #define GETL() if (!fgets(buffer, 255, file)) goto short_file
 124
 125         file = fopen(file_name, "rb");
 126         if (!file) {
 127                 RErrorCode = RERR_OPEN;
 128                 return NULL;
 129         }
 130
 131         /* get signature */
 132         GETL();
 133
 134         /* only accept raw pixmaps or graymaps */
 135         if (buffer[0] != 'P' || (buffer[1] != '5' && buffer[1] != '6')) {
 136                 RErrorCode = RERR_BADFORMAT;
 137                 fclose(file);
 138                 return NULL;
 139         }
 140
 141         type = buffer[1];
 142
 143         /* skip comments */
 144         while (1) {
 145                 GETL();
 146
 147                 if (buffer[0] != '#')
 148                         break;
 149         }
 150
 151         /* get size */
 152         if (sscanf(buffer, "%i %i", &w, &h) != 2 || w < 1 || h < 1)
 153                 goto bad_file;
 154
 155         GETL();
 156         if (sscanf(buffer, "%i", &m) != 1 || m < 1)
 157                 goto bad_file;
 158
 159         if (type == '5')
 160                 image = load_graymap(file, w, h, m, type == '5');
 161         else if (type == '6')
 162                 image = load_pixmap(file, w, h, m, type == '6');
 163
 164         fclose(file);
 165         return image;
 166
 167  bad_file:
 168  short_file:
 169         RErrorCode = RERR_BADIMAGEFILE;
 170         fclose(file);
 171         return NULL;
 172 }