old_tests/pixeltest.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) 2009-2010 Cyril Hrubis <metan@ucw.cz>                       *
  23  *                                                                           *
  24  *****************************************************************************/
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <SDL/SDL.h>
  29
  30 #include "GP.h"
  31
  32 /* The surface used as a display (in fact it is a software surface). */
  33 SDL_Surface *display = NULL;
  34
  35 /* Timer used for refreshing the display */
  36 SDL_TimerID timer;
  37
  38 /* An event used for signaling that the timer was triggered. */
  39 SDL_UserEvent timer_event;
  40
  41 /* Values for color pixels in display format. */
  42 long red;
  43 long green;
  44 long blue;
  45
  46 Uint32 timer_callback(__attribute__((unused)) Uint32 interval,
  47                         __attribute__((unused)) void *param)
  48 {
  49         timer_event.type = SDL_USEREVENT;
  50         SDL_PushEvent((SDL_Event *) &timer_event);
  51         return 30;
  52 }
  53
  54 void draw_pixels(void)
  55 {
  56         long pixel;
  57         int x = random() % 320;
  58         int y = random() % 240;
  59
  60         SDL_LockSurface(display);
  61         pixel = GP_GetPixel(display, x, y);
  62
  63         if (pixel == green)
  64                 GP_SetPixel(display, blue, x, y);
  65         else
  66                 GP_SetPixel(display, green, x, y);
  67
  68         SDL_UnlockSurface(display);
  69 }
  70
  71 void event_loop(void)
  72 {
  73         SDL_Event event;
  74
  75         while (SDL_WaitEvent(&event) > 0) {
  76
  77                 switch (event.type) {
  78                         case SDL_USEREVENT:
  79                                 draw_pixels();
  80                                 SDL_Flip(display);
  81                         break;
  82                         case SDL_KEYDOWN:
  83                         case SDL_QUIT:
  84                                 return;
  85                 }
  86         }
  87 }
  88
  89 int main(void)
  90 {
  91         /* Initialize SDL */
  92         if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) != 0) {
  93                 fprintf(stderr, "Could not initialize SDL: %s\n", SDL_GetError());
  94                 return 1;
  95         }
  96
  97         /* Create a window with a software back surface */
  98         display = SDL_SetVideoMode(320, 240, 0, SDL_SWSURFACE);
  99         if (display == NULL) {
 100                 fprintf(stderr, "Could not open display: %s\n", SDL_GetError());
 101                 goto fail;
 102         }
 103
 104         /* Print basic information about the surface */
 105         printf("Display surface properties:\n");
 106         printf("    width: %4d, height: %4d, pitch: %4d\n",
 107                display->w, display->h, display->pitch);
 108         printf("    bits per pixel: %2d, bytes per pixel: %2d\n",
 109                display->format->BitsPerPixel, display->format->BytesPerPixel);
 110
 111         /* Get colors */
 112         red = SDL_MapRGB(display->format, 255, 0, 0);
 113         green = SDL_MapRGB(display->format, 0, 255, 0);
 114         blue = SDL_MapRGB(display->format, 0, 0, 255);
 115
 116         /* Set up a clipping rectangle to test proper clipping of pixels */
 117         SDL_Rect clip_rect = {10, 10, 300, 220};
 118         SDL_SetClipRect(display, &clip_rect);
 119
 120         /* Set up the refresh timer */
 121         timer = SDL_AddTimer(30, timer_callback, NULL);
 122         if (timer == 0) {
 123                 fprintf(stderr, "Could not set up timer: %s\n", SDL_GetError());
 124                 goto fail;
 125         }
 126
 127         /* Enter the event loop */
 128         event_loop();
 129
 130         /* We're done */
 131         SDL_Quit();
 132         return 0;
 133
 134 fail:
 135         SDL_Quit();
 136         return 1;
 137 }
 138