A Simple Side-Scrolling Shooting Game - C# Game Programming: For Serious Game Creation - page 338

}
public void Render(Renderer renderer)
{
if (Dead)
{
return;
}
renderer.DrawSprite(_sprite);
}
public void Update(double elapsedTime)
{
if (Dead)
{
return;
}
Vector position ¼ _sprite.GetPosition();
position += Direction * Speed * elapsedTime;
_sprite.SetPosition(position);
}
}
}
The BulletManager only has two member variables: a list of bullets it's
managing and a rectangle representing the screen bounds. Remember to include
the using System.Drawing statement at the top of the file so that the
RectangleF class can be used. The screen bounds are used to determine if a
bullet has left the screen and can be destroyed.
The constructor takes in a rectangle, playArea , describing the playing area and
assigns it to the _bounds member. The Shoot method is used to add a bullet to
the BulletManager . Once a bullet is added, the BulletManager tracks it
until it leaves the play area or hits a ship. The Update method updates all the
bullets being tracked and then checks if any are out of bounds; finally, it deletes
any bullets that have the Dead flag set to true.
The CheckOutOfBounds function uses the rectangle intersection test
between the bullet and playing area to determine if it's off-screen. The
RemoveDeadBullets performs an interesting trick; it iterates through the list
of bullets backwards and removes any bullets that are dead. Foreach can't be