tests/SDL/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) 2009-2011 Cyril Hrubis <metan@ucw.cz>                       *
  23  *                                                                           *
  24  *****************************************************************************/
  25
  26 #include <math.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <SDL/SDL.h>
  30
  31 #include "GP.h"
  32 #include "GP_SDL.h"
  33
  34 /* The surface used as a display (in fact it is a software surface). */
  35 SDL_Surface *display = NULL;
  36 GP_Context context;
  37
  38 /* Timer used for refreshing the display */
  39 SDL_TimerID timer;
  40
  41 /* An event used for signaling that the timer was triggered. */
  42 SDL_UserEvent timer_event;
  43
  44 /* Values for color pixels in display format. */
  45 GP_Pixel black, white;
  46
  47 Uint32 timer_callback(__attribute__((unused)) Uint32 interval,
  48                         __attribute__((unused)) void * param)
  49 {
  50         timer_event.type = SDL_USEREVENT;
  51         SDL_PushEvent((SDL_Event *) &timer_event);
  52         return 30;
  53 }
  54
  55 double start_angle = 0.0;
  56
  57 static int aa_flag = 0;
  58 static int pause_flag = 0;
  59
  60 void redraw_screen(void)
  61 {
  62         double angle;
  63         int x, y;
  64         int xcenter = display->w/2;
  65         int ycenter = display->h/2;
  66
  67         SDL_LockSurface(display);
  68         GP_Fill(&context, black);
  69
  70         for (angle = 0.0; angle < 2*M_PI; angle += 0.1) {
  71                 x = (int) (display->w/2 * cos(start_angle + angle));
  72                 y = (int) (display->h/2 * sin(start_angle + angle));
  73
  74                 Uint8 r = 127.0 + 127.0 * cos(start_angle + angle);
  75                 Uint8 b = 127.0 + 127.0 * sin(start_angle + angle);
  76
  77                 GP_Pixel pixel;
  78                 pixel = GP_RGBToPixel(r, 0, b, context.pixel_type);
  79
  80                 if (aa_flag) {
  81                         GP_LineAA_Raw(&context, GP_FP_FROM_INT(xcenter), GP_FP_FROM_INT(ycenter),
  82                                 GP_FP_FROM_INT(xcenter + x), GP_FP_FROM_INT(ycenter + y), pixel);
  83                 } else {
  84                         GP_Line(&context, xcenter + x, ycenter + y, xcenter, ycenter, pixel);
  85                         GP_Line(&context, xcenter, ycenter, xcenter + x, ycenter + y, pixel);
  86                 }
  87         }
  88
  89         /* axes */
  90 //      GP_HLineXYW(&context, 0, ycenter, display->w, white);
  91 //      GP_VLineXYH(&context, xcenter, 0, display->h, white);
  92
  93         SDL_UnlockSurface(display);
  94 }
  95
  96 void event_loop(void)
  97 {
  98         SDL_Event event;
  99
 100         while (SDL_WaitEvent(&event) > 0) {
 101                 switch (event.type) {
 102                 case SDL_USEREVENT:
 103                         redraw_screen();
 104                         SDL_Flip(display);
 105
 106                         if (pause_flag)
 107                                 continue;
 108
 109                         start_angle += 0.01;
 110                         if (start_angle > 2*M_PI) {
 111                                 start_angle = 0.0;
 112                         }
 113                 break;
 114                 case SDL_KEYDOWN:
 115                         switch (event.key.keysym.sym) {
 116                         case SDLK_a:
 117                                 aa_flag = !aa_flag;
 118                         break;
 119                         case SDLK_p:
 120                                 pause_flag = !pause_flag;
 121                         break;
 122                         default:
 123                                 return;
 124                         }
 125                 break;
 126                 case SDL_QUIT:
 127                         return;
 128                 }
 129         }
 130 }
 131
 132 int main(int argc, char **argv)
 133 {
 134         GP_RetCode retcode;
 135         retcode = GP_SDL_VideoInit(&context, 640, 480, argc, argv);
 136         if (retcode != GP_ESUCCESS) {
 137                 fprintf(stderr, "Video initialization failed: %s\n",
 138                         GP_RetCodeName(retcode));
 139                 return 1;
 140         }
 141
 142         display = SDL_GetVideoSurface();
 143         GP_SDL_ContextFromSurface(&context, display);
 144
 145         /* Load colors in display format */
 146         black = GP_ColorToContextPixel(GP_COL_BLACK, &context);
 147         white = GP_ColorToContextPixel(GP_COL_WHITE, &context);
 148
 149         /* Set up the refresh timer */
 150         timer = SDL_AddTimer(30, timer_callback, NULL);
 151         if (timer == 0) {
 152                 fprintf(stderr, "Could not set up timer: %s\n", SDL_GetError());
 153                 goto fail;
 154         }
 155
 156         /* Enter the event loop */
 157         event_loop();
 158
 159         /* We're done */
 160         SDL_Quit();
 161         return 0;
 162
 163 fail:
 164         SDL_Quit();
 165         return 1;
 166 }
 167