public override void Initialize()
{
// Set random X coordinate for the first Asteroid
int x = random.Next(Asteroid.WIDTH,
Game.GraphicsDevice.Viewport.Width - Asteroid.WIDTH);
// Y coordinate: over the top of the game screen
int y = -Asteroid.HEIGHT;
// Add the first Asteroid
parent.AddComponent(new Asteroid(Game, new Vector2(x, y)));
base.Initialize();
}
/// <summary>
/// Create a new bullet at regular time interval
/// </summary>
/// <param name="gameTime">Game Time</param>
private void CreateNewBullet(GameTime gameTime)
{
createBulletTimer += gameTime.ElapsedGameTime.TotalSeconds;
if (createBulletTimer > BULLET_DUARTION)
{
// Starting X position is a middle of a Alien Spacecraft
float x = position.X + WIDTH / 2 - Bullet.WIDTH / 2;
float y = position.Y + HEIGHT;
parent.AddComponent(new Bullet(Game, new Vector2(x, y)));
createBulletTimer = 0;
}
}
public override void Update(GameTime gameTime)
{
// Set current score text (string) to display it
scoreText = $"Score : {GetScore()} points";
// Set position for display score (top, center horizontally)
scorePosition.X = Game.GraphicsDevice.Viewport.Width / 2 - scoreFont.MeasureString(scoreText).X / 2;
scorePosition.Y = scoreFont.MeasureString(scoreText).Y;
if (((GetScore() >= 100 && GetScore() < 150) ||
(GetScore() >= 1000 && GetScore() < 1050)
) && !Game.Components.OfType <Bonus>().Any())
{
// Create a Bonus on the top
Bonus bonus = new Bonus(Game, new Vector2(50, 10));
parent.AddComponent(bonus);
}
base.Update(gameTime);
}
/// <summary>
/// Move Spacecraft by user key inputs (Up/Down/Left/Right keys)
/// Fire missiles (Space key)
/// </summary>
/// <param name="gameTime"></param>
private void UpdateUserInput(GameTime gameTime)
{
KeyboardState ks = Keyboard.GetState();
if (ks.IsKeyDown(Keys.Right))
{
state = PlayerState.Right;
Position.X += SPEED;
}
else if (ks.IsKeyDown(Keys.Left))
{
state = PlayerState.Left;
Position.X -= SPEED;
}
else
{
state = PlayerState.Idle;
currentFrame = 0;
}
if (ks.IsKeyDown(Keys.Up))
{
state = PlayerState.Idle;
Position.Y -= SPEED;
currentFrame = 0;
}
else if (ks.IsKeyDown(Keys.Down))
{
state = PlayerState.Idle;
Position.Y += SPEED;
currentFrame = 0;
}
// Space Key: Shoot Missile
if (ks.IsKeyDown(Keys.Space))
{
// Check Shooting Time Inverval
shootingTimer += gameTime.ElapsedGameTime.TotalSeconds;
if (shootingTimer >= MISSILE_INTERVAL)
{
if (Missile.missileLevel == 1)
{
// Create a Missile on the top of the player
Missile missile = new Missile(Game, new Vector2(Position.X + WIDTH / 2, Position.Y));
shootingTimer = 0;
parent.AddComponent(missile);
}
else if (Missile.missileLevel == 2)
{
// Create a Missile on the top of the player
Missile missile1 = new Missile(Game, new Vector2(Position.X, Position.Y));
Missile missile2 = new Missile(Game, new Vector2(Position.X + WIDTH, Position.Y));
shootingTimer = 0;
parent.AddComponent(missile1);
parent.AddComponent(missile2);
}
}
}
// Check Boundary, a player cannot go out of the screen
int screenWidth = Game.GraphicsDevice.Viewport.Width;
int screenHeight = Game.GraphicsDevice.Viewport.Height;
Position.X = MathHelper.Clamp(Position.X, 0, screenWidth - WIDTH);
Position.Y = MathHelper.Clamp(Position.Y, 0, screenHeight - HEIGHT);
}