demos/c_simple/linetest.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) 2009-2010 Jiri "BlueBear" Dluhos                            *
  20  *                         <jiri.bluebear.dluhos@gmail.com>                  *
  21  *                                                                           *
  22  * Copyright (C) 2009-2013 Cyril Hrubis <metan@ucw.cz>                       *
  23  *                                                                           *
  24  *****************************************************************************/
  25
  26 #include <math.h>
  27
  28 #include <GP.h>
  29
  30 /* Values for color pixels in display format. */
  31 static GP_Pixel black, white;
  32
  33 static double start_angle = 0.0;
  34
  35 static int aa_flag = 0;
  36 static int pause_flag = 0;
  37
  38 static GP_Backend *win;
  39
  40 void redraw_screen(void)
  41 {
  42         double angle;
  43         int x, y;
  44         int w = win->context->w;
  45         int h = win->context->h;
  46         int xcenter = w/2;
  47         int ycenter = h/2;
  48
  49         GP_Fill(win->context, black);
  50
  51         for (angle = 0.0; angle < 2*M_PI; angle += 0.1) {
  52                 x = (int) (w/2 * cos(start_angle + angle));
  53                 y = (int) (h/2 * sin(start_angle + angle));
  54
  55                 int r = 127.0 + 127.0 * cos(start_angle + angle);
  56                 int b = 127.0 + 127.0 * sin(start_angle + angle);
  57
  58                 GP_Pixel pixel;
  59                 pixel = GP_RGBToPixel(r, 0, b, win->context->pixel_type);
  60
  61                 if (aa_flag) {
  62                         GP_LineAA_Raw(win->context, GP_FP_FROM_INT(xcenter), GP_FP_FROM_INT(ycenter),
  63                                 GP_FP_FROM_INT(xcenter + x), GP_FP_FROM_INT(ycenter + y), pixel);
  64                 } else {
  65                         GP_Line(win->context, xcenter + x, ycenter + y, xcenter, ycenter, pixel);
  66                         GP_Line(win->context, xcenter, ycenter, xcenter + x, ycenter + y, pixel);
  67                 }
  68         }
  69
  70         GP_BackendFlip(win);
  71
  72         /* axes */
  73 //      GP_HLineXYW(&context, 0, ycenter, display->w, white);
  74 //      GP_VLineXYH(&context, xcenter, 0, display->h, white);
  75 }
  76
  77 void event_loop(void)
  78 {
  79         GP_Event ev;
  80
  81         while (GP_BackendGetEvent(win, &ev)) {
  82                 switch (ev.type) {
  83                 case GP_EV_KEY:
  84                         if (ev.code != GP_EV_KEY_DOWN)
  85                                 continue;
  86
  87                         switch (ev.val.key.key) {
  88                         case GP_KEY_A:
  89                                 aa_flag = !aa_flag;
  90                         break;
  91                         case GP_KEY_ESC:
  92                                 GP_BackendExit(win);
  93                                 exit(0);
  94                         break;
  95                         case GP_KEY_P:
  96                                 pause_flag = !pause_flag;
  97                         break;
  98                         }
  99                 break;
 100                 case GP_EV_SYS:
 101                         switch(ev.code) {
 102                         case GP_EV_SYS_QUIT:
 103                                 GP_BackendExit(win);
 104                                 exit(0);
 105                         break;
 106                         case GP_EV_SYS_RESIZE:
 107                                 GP_BackendResizeAck(win);
 108                         break;
 109                         }
 110                 break;
 111                 }
 112         }
 113 }
 114
 115 int main(int argc, char *argv[])
 116 {
 117         const char *backend_opts = "X11";
 118         int opt;
 119
 120         while ((opt = getopt(argc, argv, "b:")) != -1) {
 121                 switch (opt) {
 122                 case 'b':
 123                         backend_opts = optarg;
 124                 break;
 125                 default:
 126                         fprintf(stderr, "Invalid paramter '%c'\n", opt);
 127                 }
 128         }
 129
 130         win = GP_BackendInit(backend_opts, "Line Test");
 131
 132         if (win == NULL) {
 133                 fprintf(stderr, "Failed to initalize backend '%s'\n",
 134                         backend_opts);
 135                 return 1;
 136         }
 137
 138         white = GP_ColorToContextPixel(GP_COL_WHITE, win->context);
 139         black = GP_ColorToContextPixel(GP_COL_BLACK, win->context);
 140
 141         redraw_screen();
 142
 143         for (;;) {
 144                 GP_BackendPoll(win);
 145                 event_loop();
 146
 147                 usleep(20000);
 148
 149                 if (pause_flag)
 150                         continue;
 151
 152                 redraw_screen();
 153                 GP_BackendFlip(win);
 154
 155                 start_angle += 0.01;
 156                 if (start_angle > 2*M_PI) {
 157                         start_angle = 0.0;
 158                 }
 159         }
 160 }