demos/c_simple/loaders_register.c

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2014 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23  /*
  24
  25    Shows how to register custom image loader/saver.
  26
  27    Feed it with small image (cca 60x60 pixels) to produce ASCII art version.
  28
  29   */
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <errno.h>
  34
  35 #include <gfxprim.h>
  36
  37 /*
  38  * Saves 2 bpp grayscale image as ASCII Art
  39  */
  40 static int write_data(const gp_pixmap *img, gp_io *io,
  41                       gp_progress_cb *callback)
  42 {
  43         gp_io *bio;
  44         int err;
  45
  46         if (img->pixel_type != GP_PIXEL_G4) {
  47                 errno = ENOSYS;
  48                 return 1;
  49         }
  50
  51         /* Create buffered I/O */
  52         bio = gp_io_wbuffer(io, 0);
  53
  54         if (!bio)
  55                 return 1;
  56
  57         unsigned int i, j;
  58         const char *const table[] = {" ", ".", ",", "-", "=", "#", "O", "$"};
  59
  60         for (j = 0; j < img->h; j++) {
  61                 for (i = 0; i < img->w; i++) {
  62                         gp_pixel p = gp_getpixel_raw(img, i, j);
  63                         const char *c = table[p>>1];
  64
  65                         err = gp_io_flush(bio, c, 1);
  66                         if (err)
  67                                 return 1;
  68                 }
  69
  70                 if (gp_io_flush(bio, "\n", 1))
  71                         return 1;
  72
  73                 if (gp_progress_cb_report(callback, j, img->h, img->w)) {
  74                         errno = ECANCELED;
  75                         return 1;
  76                 }
  77         }
  78
  79         gp_io_close(bio);
  80         gp_progress_cb_done(callback);
  81         return 0;
  82 }
  83
  84 static gp_pixel_type save_ptypes[] = {
  85         GP_PIXEL_G4,
  86         GP_PIXEL_UNKNOWN,
  87 };
  88
  89 const gp_loader loader = {
  90         .Write = write_data,
  91         .save_ptypes = save_ptypes,
  92         .fmt_name = "ASCII Art",
  93         .extensions = {"txt", NULL},
  94 };
  95
  96 int main(int argc, char *argv[])
  97 {
  98         gp_pixmap *c, *gc, *sc;
  99
 100         gp_loader_register(&loader);
 101
 102         /* List all loaders */
 103         gp_loaders_lists();
 104         printf("\n\n");
 105
 106         if (argc != 2) {
 107                 fprintf(stderr, "ERROR: Takes image as an argument\n");
 108                 return 1;
 109         }
 110
 111         /* Now load image and save it using our loader */
 112         c = gp_load_image(argv[1], NULL);
 113         if (c == NULL) {
 114                 fprintf(stderr, "Failed to load image: %s\n", strerror(errno));
 115                 return 1;
 116         }
 117
 118         /*
 119          * Font letters are not square resize the image so that it's twice it
 120          * original width.
 121          */
 122         gp_size w = 120;
 123         gp_size h = (w/2 * c->h + c->w/2)/c->w;
 124
 125         sc = gp_filter_resize_alloc(c, w, h, GP_INTERP_LINEAR_LF_INT, NULL);
 126         gc = gp_filter_floyd_steinberg_alloc(sc, GP_PIXEL_G4, NULL);
 127
 128         if (gc == NULL) {
 129                 fprintf(stderr, "FloydSteinberg: %s\n", strerror(errno));
 130                 return 1;
 131         }
 132
 133         printf("Saving to test.txt\n");
 134
 135         if (gp_save_image(gc, "test.txt", NULL)) {
 136                 fprintf(stderr, "Failed to save image: %s\n", strerror(errno));
 137                 return 1;
 138         }
 139
 140         return 0;
 141 }