/// <summary>
/// The base update loop calls update loops corresponding to the current game state
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values</param>
protected override void Update(GameTime gameTime)
{
// Update the game time
GameTime = gameTime;
// Switch over the current state
switch (State)
{
// Call the corresponding update functions for each menu
case GameState.MainMenu:
MainMenuScreen.Update();
break;
case GameState.Instructions:
InstructionsScreen.Update();
break;
case GameState.ModeSelection:
ModeSelectionScreen.Update();
break;
// Game Modes
case GameState.ClassicGameplay:
// Create a new gameplay screen if it is null
if (gameplayScreen == null)
{
gameplayScreen = new GameplayScreen();
}
// Update the gameplay screen
gameplayScreen.Update();
break;
// The gameplay screens are identical and differ only in the EnemyManager (what enemies spawn)
// and PlayerShip (how the player is controlled), meaning GameplayScreen can be used generically
// in handling all operations regarding drawing and updating gameplay
case GameState.FreeGameplay:
if (gameplayScreen == null)
{
gameplayScreen = new GameplayScreen();
}
gameplayScreen.Update();
break;
}
// Check to see if the game state is not in gameplay
if (State != GameState.ClassicGameplay && State != GameState.FreeGameplay)
{
// Set the gameplay screen to null since the player ship controls and enemies are agnostic
// to the current scene. The gameplay screen prevents updates to the player and enemies but
// will still draw them unless the gameplay screen is reset entirely
gameplayScreen = null;
}
// Update the root update loop
base.Update(gameTime);
}
/// <summary>
/// The base draw loop handles drawing all draw loops corresponding to the current game state
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values</param>
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.Black);
// Switch based on the current scene
switch (State)
{
// Call each corresponding draw method
case GameState.MainMenu:
MainMenuScreen.Draw(spriteBatch);
break;
case GameState.Instructions:
InstructionsScreen.Draw(spriteBatch);
break;
case GameState.ModeSelection:
ModeSelectionScreen.Draw(spriteBatch);
break;
// If the gameplayScreen is not defined because the state updates asynchronously from
// the update loop creating a new instance of gameplayScreen, ignore the current frame
// and wait until the gameplayScreen is defined
case GameState.ClassicGameplay:
if (gameplayScreen != null)
{
gameplayScreen.Draw(spriteBatch);
}
break;
case GameState.FreeGameplay:
if (gameplayScreen != null)
{
gameplayScreen.Draw(spriteBatch);
}
break;
}
}
public Game1()
{
graphics = new GraphicsDeviceManager(this);
graphics.PreferredBackBufferWidth = screenWidth;
graphics.PreferredBackBufferHeight = screenHeight;
this.IsMouseVisible = true;
Content.RootDirectory = "Content";
ScreenRectangle = new Rectangle(0, 0, screenWidth, screenHeight);
Components.Add(new InputHandler(this));
stateManager = new GameStateManager(this);
Components.Add(stateManager);
TitleMenuScreen = new TitleMenuScreen(this, stateManager);
InstructionsScreen = new InstructionsScreen(this, stateManager);
GameScreen = new GameScreen(this, stateManager);
GameOverScreen = new GameOverScreen(this, stateManager);
WinnerScreen = new WinnerScreen(this, stateManager);
stateManager.ChangeState(TitleMenuScreen);
}
public void OnClickBackToTitleScreen()
{
TitleScreen.SetActive(true);
CreditsScreen.SetActive(false);
InstructionsScreen.SetActive(false);
}
public void OnClickInstructions()
{
TitleScreen.SetActive(false);
InstructionsScreen.SetActive(true);
}
// Use this for initialization
void Start () {
instance = this;
}
void Awake() {
instance = this;
}
