///////////////////////////////////////////////////////
//
//	bounce.cpp
//
//	Jeff Ondich 11/5/99
//	Based on Mike Tie's example g2 program.
//	Last modified 11/5/99
//
//	Try these:
//
//	1. Make the ball bounce side to side.
//	2. Make the color of the ball change
//	   gradually from blue to red as the
//	   ball moves up, and back from red to
//	   blue as it moves down.
//	3. Make the ball move diagonally,
//	   bouncing off walls, floor, and
//	   ceiling when appropriate.
//
///////////////////////////////////////////////////////

#include <iostream>
#include <g2++.h>
#include <g2_X11++.h>

const int windowHeight = 500;
const int windowWidth  = 500;
const int ballRadius = 50;

int main(void)
{
	// Open a window on screen.  Keep its device ID

	int window = g2_open_X11( windowWidth, windowHeight );


	// Let's define some colors now

	int black_ink = g2_ink(window,0,0,0);
	int white_ink = g2_ink(window,1,1,1);


	// Get ready to draw.

	g2_set_background( window, white_ink );


	// Bounce the ball.

	int y = ballRadius;
	bool goingUp = true;
	while( 1 == 1 )
	{
		// Draw the ball
		g2_pen( window, black_ink );
		g2_filled_circle( window, windowWidth / 2, y, ballRadius );

		// Wait a little while
		for( int i=0; i < 1000000; i++ )
		{
		}

		// Erase the ball
		g2_pen( window, white_ink );  
		g2_filled_circle( window, windowWidth / 2, y, ballRadius );

		// Change the y-coordinate of the ball's center.
		if( goingUp )
		{
			y++;
			if( y + ballRadius > windowHeight )
			{
				y--;
				goingUp = false;
			}
		}
		else
		{
			y--;
			if( y - ballRadius < 0 )
			{
				y--;
				goingUp = true;
			}
		}

	}

	g2_close(window);

	return( 0 );
}