#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <windows.h>
#include <unistd.h>

int high,width;
int ball_x ,ball_y;
int ball_vx, ball_vy;

void gotoxy (int x, int y)
{
	HANDLE handle = GetStdHandle(STD_OUTPUT_HANDLE);
	COORD pos;
	pos.X = x;
	pos.Y = y;
	SetConsoleCursorPosition(handle, pos); 
}

void startup()
{
	high = 15;
	width = 20;
	ball_x = 0;
	ball_y = width / 2;
	ball_vx = 1;
	ball_vy = 1;
}

void show()
{
	gotoxy(0,0);
	int i, j;
	for(i = 0; i < high; i++)
	{
		for(j = 0; j < width; j++)
		{
			if((i == ball_x) && (j == ball_y))
				printf("0");
			else
				printf(" ");
		}
		printf("\n");
	}
}

void updateWithoutInput()
{
	ball_x = ball_x + ball_vx;
	ball_y = ball_y + ball_vy;
	
	if((ball_x == 0) || (ball_x = high - 1))
		ball_vx = -ball_vx;
	if((ball_y == 0) || (ball_y == width - 1))
		ball_vy = -ball_vy;
		
	usleep(50000);
}

void updateWithInput()
{
}

int main ()
{
	startup();
	while(1)
	{
		show();
		updateWithoutInput();
		updateWithInput();
	}
	return 0;
}