src/Fl_PNM_Image.cxx

   1 //
   2 // "$Id: Fl_PNM_Image.cxx 7903 2010-11-28 21:06:39Z matt $"
   3 //
   4 // Fl_PNM_Image routines.
   5 //
   6 // Copyright 1997-2010 by Easy Software Products.
   7 //
   8 // This library is free software; you can redistribute it and/or
   9 // modify it under the terms of the GNU Library General Public
  10 // License as published by the Free Software Foundation; either
  11 // version 2 of the License, or (at your option) any later version.
  12 //
  13 // This library is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 // Library General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU Library General Public
  19 // License along with this library; if not, write to the Free Software
  20 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21 // USA.
  22 //
  23 // Please report all bugs and problems on the following page:
  24 //
  25 //     http://www.fltk.org/str.php
  26 //
  27 // Contents:
  28
  29 //
  30 //   Fl_PNM_Image::Fl_PNM_Image() - Load a PNM image...
  31 //
  32
  33 //
  34 // Include necessary header files...
  35 //
  36
  37 #include <FL/Fl.H>
  38 #include <FL/Fl_PNM_Image.H>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <FL/fl_utf8.h>
  42 #include "flstring.h"
  43
  44
  45 //
  46 // 'Fl_PNM_Image::Fl_PNM_Image()' - Load a PNM image...
  47 //
  48
  49 /**
  50   The constructor loads the named PNM image.
  51   <P>The inherited destructor free all memory and server resources that are used by the image.
  52 */
  53
  54 Fl_PNM_Image::Fl_PNM_Image(const char *name)    // I - File to read
  55   : Fl_RGB_Image(0,0,0) {
  56   FILE          *fp;            // File pointer
  57   int           x, y;           // Looping vars
  58   char          line[1024],     // Input line
  59                 *lineptr;       // Pointer in line
  60   uchar         *ptr,           // Pointer to pixel values
  61                 byte,           // Byte from file
  62                 bit;            // Bit in pixel
  63   int           format,         // Format of PNM file
  64                 val,            // Pixel value
  65                 maxval;         // Maximum pixel value
  66
  67
  68   if ((fp = fl_fopen(name, "rb")) == NULL) return;
  69
  70   //
  71   // Read the file header in the format:
  72   //
  73   //   Pformat
  74   //   # comment1
  75   //   # comment2
  76   //   ...
  77   //   # commentN
  78   //   width
  79   //   height
  80   //   max sample
  81   //
  82
  83   lineptr = fgets(line, sizeof(line), fp);
  84   if (!lineptr) {
  85     fclose(fp);
  86     Fl::error("Early end-of-file in PNM file \"%s\"!", name);
  87     return;
  88   }
  89
  90   lineptr ++;
  91
  92   format = atoi(lineptr);
  93   while (isdigit(*lineptr)) lineptr ++;
  94
  95   if (format == 7) lineptr = (char *)"";
  96
  97   while (lineptr != NULL && w() == 0) {
  98     if (*lineptr == '\0' || *lineptr == '#') {
  99       lineptr = fgets(line, sizeof(line), fp);
 100     } else if (isdigit(*lineptr)) {
 101       w(strtol(lineptr, &lineptr, 10));
 102     } else lineptr ++;
 103   }
 104
 105   while (lineptr != NULL && h() == 0) {
 106     if (*lineptr == '\0' || *lineptr == '#') {
 107       lineptr = fgets(line, sizeof(line), fp);
 108     } else if (isdigit(*lineptr)) {
 109       h(strtol(lineptr, &lineptr, 10));
 110     } else lineptr ++;
 111   }
 112
 113   if (format != 1 && format != 4) {
 114     maxval = 0;
 115
 116     while (lineptr != NULL && maxval == 0) {
 117       if (*lineptr == '\0' || *lineptr == '#') {
 118         lineptr = fgets(line, sizeof(line), fp);
 119       } else if (isdigit(*lineptr)) {
 120         maxval = strtol(lineptr, &lineptr, 10);
 121       } else lineptr ++;
 122     }
 123   } else maxval = 1;
 124
 125   // Allocate memory...
 126   if (format == 1 || format == 2 || format == 4 || format == 5) d(1);
 127   else d(3);
 128
 129 //  printf("%s = %dx%dx%d\n", name, w(), h(), d());
 130
 131   array       = new uchar[w() * h() * d()];
 132   alloc_array = 1;
 133
 134   // Read the image file...
 135   for (y = 0; y < h(); y ++) {
 136     ptr = (uchar *)array + y * w() * d();
 137
 138     switch (format) {
 139       case 1 :
 140       case 2 :
 141           for (x = w(); x > 0; x --)
 142             if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
 143           break;
 144
 145       case 3 :
 146           for (x = w(); x > 0; x --) {
 147             if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
 148             if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
 149             if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
 150           }
 151           break;
 152
 153       case 4 :
 154           for (x = w(), byte = (uchar)getc(fp), bit = 128; x > 0; x --) {
 155             if (byte & bit) *ptr++ = 255;
 156             else *ptr++ = 0;
 157
 158             if (bit > 1) bit >>= 1;
 159             else {
 160               bit  = 128;
 161               byte = (uchar)getc(fp);
 162             }
 163           }
 164           break;
 165
 166       case 5 :
 167       case 6 :
 168         if (maxval < 256) {
 169           if (fread(ptr, w(), d(), fp)) { /* ignored */ }
 170         } else {
 171           for (x = d() * w(); x > 0; x --) {
 172             val = (uchar)getc(fp);
 173             val = (val<<8)|(uchar)getc(fp);
 174             *ptr++ = (255*val)/maxval;
 175           }
 176         }
 177         break;
 178
 179       case 7 : /* XV 3:3:2 thumbnail format */
 180         for (x = w(); x > 0; x --) {
 181           byte = (uchar)getc(fp);
 182
 183           *ptr++ = (uchar)(255 * ((byte >> 5) & 7) / 7);
 184           *ptr++ = (uchar)(255 * ((byte >> 2) & 7) / 7);
 185           *ptr++ = (uchar)(255 * (byte & 3) / 3);
 186         }
 187         break;
 188     }
 189   }
 190
 191   fclose(fp);
 192 }
 193
 194
 195 //
 196 // End of "$Id: Fl_PNM_Image.cxx 7903 2010-11-28 21:06:39Z matt $".
 197 //