/// <summary>
/// Handle a movement of the gaze point.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
internal void OnGazeMove(object sender, GazeEventArgs e)
{
// add the gaze point to the history, keep a queue of 10 values
gazeHistory.Enqueue(e.Point.X);
if (gazeHistory.Count > 10)
{
gazeHistory.Dequeue();
}
// calculate average gaze position
var average = gazeHistory.Average(x => x);
// move the paddle so its center aligns with the average location
_pos.X = (int)average - _size.Width / 2;
}
/// <summary>
/// Update the game board.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void tmr_Tick(object sender, EventArgs e)
{
// get the current gaze point
var gea = new GazeEventArgs();
OnGazeMove?.Invoke(this, gea);
// perform calibration for one second
var interval = ((Timer)sender).Interval;
if (_frameIndex < 1000 / interval)
{
gazeOffset.X -= (_dot._pos.X - this.Width / 2);
}
// after the calibration period, kill the circle and text and start the game
else
{
if (!_circle.IsDead)
{
_circle.IsDead = true;
_text.IsDead = true;
Invalidate(_circle.GetRect());
Invalidate(_text.GetRect());
}
}
// apply offset to gaze point
gea.Point.X += gazeOffset.X;
// move the paddle
Invalidate(_paddle.GetRect());
_paddle.OnGazeMove(this, gea);
Invalidate(_paddle.GetRect());
// move the gaze dot
Invalidate(_dot.GetRect());
_dot._pos.X = gea.Point.X;
Invalidate(_dot.GetRect());
Point res;
for (int iBall = 0; iBall < _NumBalls; iBall++)
{
// check if the ball is alive
var ball = _balls[iBall];
if (!ball.IsDead)
{
// detect collisions with the wall
res = DetectCollision(ball, ClientRectangle, fShouldBeInside: true);
if (res.X == 0 && res.Y == 0)
{
// detect colissions with the paddle
res = DetectCollision(ball, _paddle.GetRect(), fShouldBeInside: false);
if (res.X == 0 && res.Y == 0)
{
// all blocks gone?
if (_numBlocksAlive == 0)
{
// increment level
_nLevels++;
// build more blocks
_nBlocksY++;
// bring all balls back to life
int nBallsToBringBackToLife = 0;
for (int i = 0; i < _NumBalls; i++)
{
if (_balls[i].IsDead)
{
_balls[i].IsDead = false;
_balls[i]._pos.X = 100 + 10 * i;
_balls[i]._pos.Y = 100 + 10 * i;
_NumBallsAlive++;
Invalidate(_balls[i].GetRect());
if (++nBallsToBringBackToLife == 3)
{
break;
}
}
}
// recreate the blocks
CreateBlocks();
}
// some blocks remaining
else
{
// detect collision with any block
for (int i = 0; i < _nBlocksX; i++)
{
for (int j = 0; j < _nBlocksY; j++)
{
if (!_blocks[i, j].IsDead)
{
res = DetectCollision(ball, _blocks[i, j].GetRect(), fShouldBeInside: false);
if (res.X != 0 || res.Y != 0)
{
// kill the block
_blocks[i, j].IsDead = true;
_numBlocksAlive--;
_Score++;
Invalidate(_blocks[i, j].GetRect());
}
}
}
}
}
}
// ball hit the paddle
else
{
// bounce handled elsewhere
}
}
// ball hit the wall
else
{
// if the ball hit the bottom wall, it's dead
if (res.Y == -1)
{
ball.IsDead = true;
Invalidate(ball.GetRect());
_NumBallsAlive--;
}
}
// update the ball position
Invalidate(ball.GetRect());
ball._pos.X += ball._velocity.X;
ball._pos.Y += ball._velocity.Y;
Invalidate(ball.GetRect());
}
}
// stop the timer if all balls are dead
if (_NumBallsAlive == 0)
{
this._timer.Enabled = false;
}
// update the frame counter
_frameIndex++;
// update game status
this.Text = string.Format(
"Score = {0} # Levels = {1} # of balls left = {2}",
_Score,
_nLevels,
_NumBallsAlive);
}