#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <SDL/SDL.h>
#include <windows.h>
#include <math.h>

#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600
#define SCREEN_DEPTH 16

#define SCALE 10

const int radius = 200;
int angle = 0;

#define _X(x) ((SCREEN_WIDTH / 2) + (x))

#define _Y(y) return (T)((SCREEN_HEIGHT / 2) - (y))

/* The screen surface */
SDL_Surface *screen = NULL;

void draw ()
{
	angle++;
	SDL_Rect box;
	box.w = 40;
	box.h = 40;

	double cosx;

	cosx = cos(deg2rad(angle));

	box.x = (int)_X(cosx*radius) ;
	box.y = (int)_X(cosx*radius);
	
	//SDL_FillRect(screen, NULL, SDL_MapRGB(screen->format, 0, 0, 0));
	SDL_FillRect(screen, &box, SDL_MapRGB(screen->format, 255, 0, 0));


    /* Make sure everything is displayed on screen */
    SDL_Flip (screen);
    /* Don't run too fast */
    SDL_Delay (1);
}


int main (int argc, char *argv[])
{
    char *msg;
    int done;

    /* Initialize SDL */
    if (SDL_Init (SDL_INIT_VIDEO) < 0)
    {
        sprintf (msg, "Couldn't initialize SDL: %s\n", SDL_GetError ());
        MessageBox (0, msg, "Error", MB_ICONHAND); 
        free (msg);
        exit (1);
    }
    atexit (SDL_Quit);

    /* Set 640x480 16-bits video mode */
    screen = SDL_SetVideoMode (SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_DEPTH, SDL_SWSURFACE | SDL_DOUBLEBUF);
    if (screen == NULL)
    {
        sprintf (msg, "Couldn't set 640x480x16 video mode: %s\n",
          SDL_GetError ());
        MessageBox (0, msg, "Error", MB_ICONHAND); 
        free (msg);
        exit (2);
    }
    SDL_WM_SetCaption ("Circulator Rotation around a Vertex", NULL);

    done = 0;
    while (!done)
    {
        SDL_Event event;

        /* Check for events */
        while (SDL_PollEvent (&event))
        {
            switch (event.type)
            {
            case SDL_KEYDOWN:
                break;
            case SDL_QUIT:
                done = 1;
                break;
            default:
                break;
            }
        }

        /* Draw to screen */
        draw ();
    }

    return 0;
}