demos/c_simple/convolution.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) 2009-2012 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23  /*
  24
  25    Convolution filter example.
  26
  27   */
  28
  29 #include <stdio.h>
  30 #include <string.h>
  31 #include <errno.h>
  32
  33 #include <GP.h>
  34
  35 struct callback_priv {
  36         char *op;
  37         char *name;
  38 };
  39
  40 static int progress_callback(GP_ProgressCallback *self)
  41 {
  42         struct callback_priv *priv = self->priv;
  43
  44         printf("\r%s '%s' %3.1f%%", priv->op, priv->name, self->percentage);
  45         fflush(stdout);
  46
  47         /*
  48          * It's important to return zero as non-zero return value
  49          * aborts the operation.
  50          */
  51         return 0;
  52 }
  53
  54 int main(int argc, char *argv[])
  55 {
  56         GP_Pixmap *img;
  57         struct callback_priv priv;
  58         GP_ProgressCallback callback = {.callback = progress_callback,
  59                                         .priv = &priv};
  60
  61         if (argc != 2) {
  62                 fprintf(stderr, "Takes an image as an parameter\n");
  63                 return 1;
  64         }
  65
  66         priv.op   = "Loading";
  67         priv.name = argv[1];
  68
  69         img = GP_LoadImage(argv[1], &callback);
  70
  71         if (img == NULL) {
  72                 fprintf(stderr, "Failed to load image '%s': %s\n", argv[1],
  73                         strerror(errno));
  74                 return 1;
  75         }
  76
  77         printf("\n");
  78
  79
  80         GP_FilterKernel2D box = {
  81                 .w = 5,
  82                 .h = 5,
  83                 .div = 11.8,
  84                 .kernel = (float[]) {
  85                         0.0, 0.1, 1.0, 0.1, 0.0,
  86                         0.1, 0.5, 1.0, 0.5, 0.1,
  87                         1.0, 1.0, 1.0, 1.0, 1.0,
  88                         0.1, 0.5, 1.0, 0.5, 0.1,
  89                         0.0, 0.1, 1.0, 0.1, 0.0,
  90                 }
  91         };
  92
  93         priv.op = "Linear Convolution";
  94
  95         /*
  96          * Blur in-place, inner rectangle of the image.
  97          */
  98         GP_FilterConvolutionEx(img, img->w/4, img->h/4, img->w/2, img->h/2,
  99                                img, img->w/4, img->h/4, &box, &callback);
 100
 101         printf("\n");
 102
 103         priv.op   = "Saving";
 104         priv.name = "out.png";
 105
 106         if (GP_SavePNG(img, "out.png", &callback)) {
 107                 fprintf(stderr, "Failed to save image: %s", strerror(errno));
 108                 return 1;
 109         }
 110
 111         printf("\n");
 112
 113         return 0;
 114 }