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 #include "imgformat.h"
  32
  33 static RImage *load_graymap(FILE * file, int w, int h, int max, int raw)
  34 {
  35         RImage *image;
  36
  37         image = RCreateImage(w, h, 0);
  38         if (!image) {
  39                 return NULL;
  40         }
  41         if (!raw) {
  42
  43         } else {
  44                 if (max < 256) {
  45                         unsigned char *ptr;
  46                         char *buf;
  47                         int x, y;
  48
  49                         buf = malloc(w + 1);
  50                         if (!buf) {
  51                                 return NULL;
  52                         }
  53
  54                         ptr = image->data;
  55                         for (y = 0; y < h; y++) {
  56                                 if (!fread(buf, w, 1, file)) {
  57                                         free(buf);
  58                                         goto short_file;
  59                                 }
  60                                 for (x = 0; x < w; x++) {
  61                                         *(ptr++) = buf[x];
  62                                         *(ptr++) = buf[x];
  63                                         *(ptr++) = buf[x];
  64                                 }
  65                         }
  66                         free(buf);
  67                 } else {
  68
  69                 }
  70         }
  71
  72         return image;
  73
  74  short_file:
  75         RErrorCode = RERR_BADIMAGEFILE;
  76         return NULL;
  77 }
  78
  79 static RImage *load_pixmap(FILE * file, int w, int h, int max, int raw)
  80 {
  81         RImage *image;
  82         int i;
  83         char buf[3];
  84         unsigned char *ptr;
  85
  86         image = RCreateImage(w, h, 0);
  87         if (!image) {
  88                 return NULL;
  89         }
  90         ptr = image->data;
  91         if (!raw) {
  92
  93         } else {
  94                 if (max < 256) {
  95                         i = 0;
  96                         while (i < w * h) {
  97                                 if (fread(buf, 1, 3, file) != 3)
  98                                         goto short_file;
  99                                 *(ptr++) = buf[0];
 100                                 *(ptr++) = buf[1];
 101                                 *(ptr++) = buf[2];
 102                                 i++;
 103                         }
 104                 } else {
 105
 106                 }
 107         }
 108
 109         return image;
 110
 111  short_file:
 112         RErrorCode = RERR_BADIMAGEFILE;
 113         return NULL;
 114 }
 115
 116 RImage *RLoadPPM(const char *file_name)
 117 {
 118         FILE *file;
 119         RImage *image = NULL;
 120         char buffer[256];
 121         int w, h, m;
 122         int type;
 123
 124 #define GETL() if (!fgets(buffer, 255, file)) goto short_file
 125
 126         file = fopen(file_name, "rb");
 127         if (!file) {
 128                 RErrorCode = RERR_OPEN;
 129                 return NULL;
 130         }
 131
 132         /* get signature */
 133         GETL();
 134
 135         /* only accept raw pixmaps or graymaps */
 136         if (buffer[0] != 'P' || (buffer[1] != '5' && buffer[1] != '6')) {
 137                 RErrorCode = RERR_BADFORMAT;
 138                 fclose(file);
 139                 return NULL;
 140         }
 141
 142         type = buffer[1];
 143
 144         /* skip comments */
 145         while (1) {
 146                 GETL();
 147
 148                 if (buffer[0] != '#')
 149                         break;
 150         }
 151
 152         /* get size */
 153         if (sscanf(buffer, "%i %i", &w, &h) != 2 || w < 1 || h < 1)
 154                 goto bad_file;
 155
 156         GETL();
 157         if (sscanf(buffer, "%i", &m) != 1 || m < 1)
 158                 goto bad_file;
 159
 160         if (type == '5')
 161                 image = load_graymap(file, w, h, m, type == '5');
 162         else if (type == '6')
 163                 image = load_pixmap(file, w, h, m, type == '6');
 164
 165         fclose(file);
 166         return image;
 167
 168  bad_file:
 169  short_file:
 170         RErrorCode = RERR_BADIMAGEFILE;
 171         fclose(file);
 172         return NULL;
 173 }