demos/c_simple/backend_example.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 backend example.
  26
  27   */
  28
  29 #include <stdio.h>
  30 #include <GP.h>
  31
  32 static void redraw(GP_Backend *self)
  33 {
  34         GP_Pixmap *pixmap = self->pixmap;
  35         GP_Pixel white_pixel, black_pixel;
  36
  37         black_pixel = GP_RGBToPixmapPixel(0x00, 0x00, 0x00, pixmap);
  38         white_pixel = GP_RGBToPixmapPixel(0xff, 0xff, 0xff, pixmap);
  39
  40         GP_Fill(pixmap, black_pixel);
  41         GP_Line(pixmap, 0, 0, pixmap->w - 1, pixmap->h - 1, white_pixel);
  42         GP_Line(pixmap, 0, pixmap->h - 1, pixmap->w - 1, 0, white_pixel);
  43
  44         /* Update the backend screen */
  45         GP_BackendFlip(self);
  46 }
  47
  48 int main(int argc, char *argv[])
  49 {
  50         GP_Backend *backend;
  51         const char *backend_opts = "X11:100x100";
  52         int opt;
  53
  54         while ((opt = getopt(argc, argv, "b:h")) != -1) {
  55                 switch (opt) {
  56                 case 'b':
  57                         backend_opts = optarg;
  58                 break;
  59                 case 'h':
  60                         GP_BackendInit(NULL, NULL);
  61                         return 0;
  62                 break;
  63                 default:
  64                         fprintf(stderr, "Invalid paramter '%c'\n", opt);
  65                         return 1;
  66                 }
  67         }
  68
  69         backend = GP_BackendInit(backend_opts, "Backend Example");
  70
  71         if (backend == NULL) {
  72                 fprintf(stderr, "Failed to initialize backend\n");
  73                 return 1;
  74         }
  75
  76         redraw(backend);
  77
  78         /* Handle events */
  79         for (;;) {
  80                 GP_Event ev;
  81
  82                 GP_BackendWaitEvent(backend, &ev);
  83
  84                 GP_EventDump(&ev);
  85
  86                 switch (ev.type) {
  87                 case GP_EV_KEY:
  88                         switch (ev.val.val) {
  89                         case GP_KEY_ESC:
  90                         case GP_KEY_Q:
  91                                 GP_BackendExit(backend);
  92                                 return 0;
  93                         break;
  94                         }
  95                 break;
  96                 case GP_EV_SYS:
  97                         switch (ev.code) {
  98                         case GP_EV_SYS_RESIZE:
  99                                 GP_BackendResizeAck(backend);
 100                                 redraw(backend);
 101                         break;
 102                         case GP_EV_SYS_QUIT:
 103                                 GP_BackendExit(backend);
 104                                 return 0;
 105                         break;
 106                         }
 107                 break;
 108                 }
 109         }
 110
 111         GP_BackendExit(backend);
 112
 113         return 0;
 114 }