demos/c_simple/showimage.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) 2009-2013 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23 /*
  24
  25   Simple example that shows X11 window with image.
  26
  27  */
  28
  29 #include <stdio.h>
  30 #include <errno.h>
  31 #include <string.h>
  32
  33 #include <gfxprim.h>
  34
  35 int main(int argc, char *argv[])
  36 {
  37         gp_backend *backend;
  38         gp_pixmap *image;
  39
  40         if (argc != 2) {
  41                 fprintf(stderr, "Takes image as an argument\n");
  42                 return 1;
  43         }
  44
  45         /* Load image */
  46         image = gp_load_image(argv[1], NULL);
  47
  48         if (!image) {
  49                 fprintf(stderr, "Failed to load bitmap: %s\n", strerror(errno));
  50                 return 1;
  51         }
  52
  53         /* Initalize backend */
  54         backend = gp_x11_init(NULL, 0, 0, image->w, image->h, argv[1], 0);
  55
  56         if (!backend) {
  57                 fprintf(stderr, "Failed to initalize backend\n");
  58                 return 1;
  59         }
  60
  61         /* Blit image into the window and show it */
  62         gp_blit(image, 0, 0, image->w, image->h, backend->pixmap, 0, 0);
  63         gp_backend_flip(backend);
  64
  65         /* Wait for events  */
  66         for (;;) {
  67                 gp_event ev;
  68
  69                 gp_backend_wait_event(backend, &ev);
  70
  71                 if (ev.type == GP_EV_KEY && ev.val.val == GP_KEY_Q) {
  72                         gp_backend_exit(backend);
  73                         return 0;
  74                 }
  75
  76                 if (ev.type == GP_EV_SYS && ev.code == GP_EV_SYS_RESIZE) {
  77                         int cx, cy;
  78
  79                         gp_backend_resize_ack(backend);
  80
  81                         cx = ((int)backend->pixmap->w - (int)image->w) / 2;
  82                         cy = ((int)backend->pixmap->h - (int)image->h) / 2;
  83
  84                         gp_fill(backend->pixmap, 0);
  85                         gp_blit_clipped(image, 0, 0, image->w, image->h, backend->pixmap, cx, cy);
  86                         gp_backend_flip(backend);
  87                 }
  88         }
  89
  90         return 0;
  91 }