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 #include <X11/Xlib.h>
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28
  29 #include "wraster.h"
  30
  31 static RImage *load_graymap(FILE * file, int w, int h, int max, int raw)
  32 {
  33         RImage *image;
  34
  35         image = RCreateImage(w, h, 0);
  36         if (!image) {
  37                 return NULL;
  38         }
  39         if (!raw) {
  40
  41         } else {
  42                 if (max < 256) {
  43                         unsigned char *ptr;
  44                         char *buf;
  45                         int x, y;
  46
  47                         buf = malloc(w + 1);
  48                         if (!buf) {
  49                                 return NULL;
  50                         }
  51
  52                         ptr = image->data;
  53                         for (y = 0; y < h; y++) {
  54                                 if (!fread(buf, w, 1, file)) {
  55                                         free(buf);
  56                                         goto short_file;
  57                                 }
  58                                 for (x = 0; x < w; x++) {
  59                                         *(ptr++) = buf[x];
  60                                         *(ptr++) = buf[x];
  61                                         *(ptr++) = buf[x];
  62                                 }
  63                         }
  64                         free(buf);
  65                 } else {
  66
  67                 }
  68         }
  69
  70         return image;
  71
  72  short_file:
  73         RErrorCode = RERR_BADIMAGEFILE;
  74         return NULL;
  75 }
  76
  77 static RImage *load_pixmap(FILE * file, int w, int h, int max, int raw)
  78 {
  79         RImage *image;
  80         int i;
  81         char buf[3];
  82         unsigned char *ptr;
  83
  84         image = RCreateImage(w, h, 0);
  85         if (!image) {
  86                 return NULL;
  87         }
  88         ptr = image->data;
  89         if (!raw) {
  90
  91         } else {
  92                 if (max < 256) {
  93                         i = 0;
  94                         while (i < w * h) {
  95                                 if (fread(buf, 1, 3, file) != 3)
  96                                         goto short_file;
  97                                 *(ptr++) = buf[0];
  98                                 *(ptr++) = buf[1];
  99                                 *(ptr++) = buf[2];
 100                                 i++;
 101                         }
 102                 } else {
 103
 104                 }
 105         }
 106
 107         return image;
 108
 109  short_file:
 110         RErrorCode = RERR_BADIMAGEFILE;
 111         return NULL;
 112 }
 113
 114 RImage *RLoadPPM(char *file_name)
 115 {
 116         FILE *file;
 117         RImage *image = NULL;
 118         char buffer[256];
 119         int w, h, m;
 120         int type;
 121
 122 #define GETL() if (!fgets(buffer, 255, file)) goto short_file
 123
 124         file = fopen(file_name, "rb");
 125         if (!file) {
 126                 RErrorCode = RERR_OPEN;
 127                 return NULL;
 128         }
 129
 130         /* get signature */
 131         GETL();
 132
 133         /* only accept raw pixmaps or graymaps */
 134         if (buffer[0] != 'P' || (buffer[1] != '5' && buffer[1] != '6')) {
 135                 RErrorCode = RERR_BADFORMAT;
 136                 fclose(file);
 137                 return NULL;
 138         }
 139
 140         type = buffer[1];
 141
 142         /* skip comments */
 143         while (1) {
 144                 GETL();
 145
 146                 if (buffer[0] != '#')
 147                         break;
 148         }
 149
 150         /* get size */
 151         if (sscanf(buffer, "%i %i", &w, &h) != 2 || w < 1 || h < 1)
 152                 goto bad_file;
 153
 154         GETL();
 155         if (sscanf(buffer, "%i", &m) != 1 || m < 1)
 156                 goto bad_file;
 157
 158         if (type == '5')
 159                 image = load_graymap(file, w, h, m, type == '5');
 160         else if (type == '6')
 161                 image = load_pixmap(file, w, h, m, type == '6');
 162
 163         fclose(file);
 164         return image;
 165
 166  bad_file:
 167  short_file:
 168         RErrorCode = RERR_BADIMAGEFILE;
 169         fclose(file);
 170         return NULL;
 171 }