Silnik aparatu XNA 2D, który śledzi Sprite

Question

Jaki jest najlepszy sposób na stworzenie efektu paralaksy w grze XNA? Chciałbym, żeby kamera podążała za moim duszkiem, gdy porusza się po świecie, dzięki czemu mogę budować efekty takie jak zoom, przesuwanie, potrząsanie i inne efekty. Ktoś ma solidny przykład tego, jak to się robi, najlepiej w GameComponent?

Answer 1

Więc zorientowaliśmy się, stosując kombinację ćwiczeń powyżej stworzyliśmy klasę poniżej. Dopasowuje się do celu i podąża za nim. Wypróbuj to.

public interface IFocusable 
{ 
    Vector2 Position { get; } 
} 

public interface ICamera2D 
{ 
    /// <summary> 
    /// Gets or sets the position of the camera 
    /// </summary> 
    /// <value>The position.</value> 
    Vector2 Position { get; set; } 

    /// <summary> 
    /// Gets or sets the move speed of the camera. 
    /// The camera will tween to its destination. 
    /// </summary> 
    /// <value>The move speed.</value> 
    float MoveSpeed { get; set; } 

    /// <summary> 
    /// Gets or sets the rotation of the camera. 
    /// </summary> 
    /// <value>The rotation.</value> 
    float Rotation { get; set; } 

    /// <summary> 
    /// Gets the origin of the viewport (accounts for Scale) 
    /// </summary>   
    /// <value>The origin.</value> 
    Vector2 Origin { get; } 

    /// <summary> 
    /// Gets or sets the scale of the Camera 
    /// </summary> 
    /// <value>The scale.</value> 
    float Scale { get; set; } 

    /// <summary> 
    /// Gets the screen center (does not account for Scale) 
    /// </summary> 
    /// <value>The screen center.</value> 
    Vector2 ScreenCenter { get; } 

    /// <summary> 
    /// Gets the transform that can be applied to 
    /// the SpriteBatch Class. 
    /// </summary> 
    /// <see cref="SpriteBatch"/> 
    /// <value>The transform.</value> 
    Matrix Transform { get; } 

    /// <summary> 
    /// Gets or sets the focus of the Camera. 
    /// </summary> 
    /// <seealso cref="IFocusable"/> 
    /// <value>The focus.</value> 
    IFocusable Focus { get; set; } 

    /// <summary> 
    /// Determines whether the target is in view given the specified position. 
    /// This can be used to increase performance by not drawing objects 
    /// directly in the viewport 
    /// </summary> 
    /// <param name="position">The position.</param> 
    /// <param name="texture">The texture.</param> 
    /// <returns> 
    ///  <c>true</c> if the target is in view at the specified position; otherwise, <c>false</c>. 
    /// </returns> 
    bool IsInView(Vector2 position, Texture2D texture); 
} 

public class Camera2D : GameComponent, ICamera2D 
{ 
    private Vector2 _position; 
    protected float _viewportHeight; 
    protected float _viewportWidth; 

    public Camera2D(Game game) 
     : base(game) 
    {} 

    #region Properties 

    public Vector2 Position 
    { 
     get { return _position; } 
     set { _position = value; } 
    } 
    public float Rotation { get; set; } 
    public Vector2 Origin { get; set; } 
    public float Scale { get; set; } 
    public Vector2 ScreenCenter { get; protected set; } 
    public Matrix Transform { get; set; } 
    public IFocusable Focus { get; set; } 
    public float MoveSpeed { get; set; } 

    #endregion 

    /// <summary> 
    /// Called when the GameComponent needs to be initialized. 
    /// </summary> 
    public override void Initialize() 
    { 
     _viewportWidth = Game.GraphicsDevice.Viewport.Width; 
     _viewportHeight = Game.GraphicsDevice.Viewport.Height; 

     ScreenCenter = new Vector2(_viewportWidth/2, _viewportHeight/2); 
     Scale = 1; 
     MoveSpeed = 1.25f; 

     base.Initialize(); 
    } 

    public override void Update(GameTime gameTime) 
    { 
     // Create the Transform used by any 
     // spritebatch process 
     Transform = Matrix.Identity* 
        Matrix.CreateTranslation(-Position.X, -Position.Y, 0)* 
        Matrix.CreateRotationZ(Rotation)* 
        Matrix.CreateTranslation(Origin.X, Origin.Y, 0)* 
        Matrix.CreateScale(new Vector3(Scale, Scale, Scale)); 

     Origin = ScreenCenter/Scale; 

     // Move the Camera to the position that it needs to go 
     var delta = (float) gameTime.ElapsedGameTime.TotalSeconds; 

     _position.X += (Focus.Position.X - Position.X) * MoveSpeed * delta; 
     _position.Y += (Focus.Position.Y - Position.Y) * MoveSpeed * delta; 

     base.Update(gameTime); 
    } 

    /// <summary> 
    /// Determines whether the target is in view given the specified position. 
    /// This can be used to increase performance by not drawing objects 
    /// directly in the viewport 
    /// </summary> 
    /// <param name="position">The position.</param> 
    /// <param name="texture">The texture.</param> 
    /// <returns> 
    ///  <c>true</c> if [is in view] [the specified position]; otherwise, <c>false</c>. 
    /// </returns> 
    public bool IsInView(Vector2 position, Texture2D texture) 
    { 
     // If the object is not within the horizontal bounds of the screen 

     if ((position.X + texture.Width) < (Position.X - Origin.X) || (position.X) > (Position.X + Origin.X)) 
      return false; 

     // If the object is not within the vertical bounds of the screen 
     if ((position.Y + texture.Height) < (Position.Y - Origin.Y) || (position.Y) > (Position.Y + Origin.Y)) 
      return false; 

     // In View 
     return true; 
    } 
} 

A oto w jaki sposób używać go z SpriteBatch:

spriteBatch.Begin(SpriteBlendMode.AlphaBlend, 
        SpriteSortMode.FrontToBack, 
        SaveStateMode.SaveState, 
        Camera.Transform); 
spriteBatch.Draw(_heliTexture, 
       _heliPosition, 
       heliSourceRectangle, 
       Color.White, 
       0.0f, 
       new Vector2(0,0), 
       0.5f, 
       SpriteEffects.FlipHorizontally, 
       0.0f); 
spriteBatch.End(); 

Daj mi znać, jeśli to pomaga się, a dzięki StackOverflow i społeczności. W00t!

Answer 2

Oto kilka tutoriali na realizację kamerę 2D w XNA:

1. http://www.paradeofrain.com/?page_id=32
2. http://gamecamp.no/blogs/tutorials/archive/2008/01/29/creating-a-simple-xna-camera-class.aspx

Answer 3

Oto kolejny jeden

http://www.david-amador.com/2009/10/xna-camera-2d-with-zoom-and-rotation/

Answer 4

Wiem, że to stare pytanie, ale miałem ten sam jeden i znalazłem to wielka biblioteka kamera Monogame więc pomyślałem, że powinienem dzielić ...

https://github.com/aloisdeniel/Comora

to jest naprawdę łatwe do zainstalowania i podążać ikonki trzeba tylko dodać

this.camera.Position = pozycja twojego duszka;