public void UpdatePosition()
{
shots.UpdatePosition(game.BounceBack, game.SunLocation,
game.InverseGravity, game.Gravity);
if ((state != ShipState.Normal) &&
(state != ShipState.HyperCharge))
{
return;
}
position += velocity;
// Check the game boundaries. If bounce back mode is enabled,
// reverse the velocity when we reach the edge
if (game.BounceBack)
{
if (position.X > screenBounds.Right || position.X < screenBounds.Left)
{
velocity.X = -velocity.X;
}
if (position.Y > screenBounds.Bottom || position.Y < screenBounds.Top)
{
velocity.Y = -velocity.Y;
}
}
else
{
if (position.X > screenBounds.Right)
{
position.X = screenBounds.Left;
}
if (position.X < screenBounds.Left)
{
position.X = screenBounds.Right;
}
if (position.Y > screenBounds.Bottom)
{
position.Y = screenBounds.Top;
}
if (position.Y < screenBounds.Top)
{
position.Y = screenBounds.Bottom;
}
}
// update velocity due to the gravity of the sun...
Point sunLocation = game.SunLocation;
Vector2 gravity = new Vector2(sunLocation.X - position.X, sunLocation.Y - position.Y);
float length = Vector2.Length(gravity);
gravity = Vector2.Normalize(gravity);
gravity = (gravity * game.Gravity) * (1.0f / (length * length));
if (game.InverseGravity)
{
velocity -= gravity;
}
else
{
velocity += gravity;
}
if (length < Constants.SunCollisionLimit)
{
SetState(ShipState.Dying);
game.SendPointToAllPlayers();
}
}
