Question

对于那些熟悉farseer的人，我有一个关于碰撞检测的问题。我已经阅读了很多内容，并观看了Joran Omark撰写的关于XNAtutorial的优秀视频教程。不幸的是他使用了旧版本的farseer（2006版本），所以我不得不稍微调整一下以让我的工作。现在一切正常，除了我的碰撞检测。我似乎无法让那些工作。我决定采用screenmanager方法，因此创建了很好的单独类。

我的GameplayScreen看起来像这样

   public class GamePlayScreen : GameScreen
{
    Texture2D stewieTexture;
    Texture2D floorTexture;
    Sprite stewie;
    Sprite floor;
    World world;

    public GamePlayScreen()
    {
        world = new World(new Vector2(0, 9.81F));
        EnabledGestures = GestureType.Flick;
    }

    public override void LoadContent()
    {
        stewieTexture = ScreenManager.Game.Content.Load<Texture2D>("playerStewie");
        floorTexture = ScreenManager.Game.Content.Load<Texture2D>("Floor");

        this.stewie = new Sprite();
        this.floor = new Sprite();
        this.stewie.LoadGraphicsContent(ScreenManager.SpriteBatch, this.stewieTexture, world);
        this.floor.LoadGraphicsContent(ScreenManager.SpriteBatch, this.floorTexture, world);
       // very ugly unfortunately for now like this.. We need Textures for our sprite that's why
        this.stewie.Initialize(world, BodyType.Dynamic ,new Vector2(16000,1500));
        this.floor.Initialize(world, BodyType.Static, new Vector2(1500, 16000));
    }

    public override void HandleInput(InputState input)
    {
        foreach (GestureSample gesture in input.Gestures)
        {
            if (gesture.GestureType == GestureType.Flick)
            {
                stewie.PhysicsBody.ApplyForce(Vector2.Divide(gesture.Delta, 0.5f));
            }
        }
    }

    public override void Update(GameTime gameTime, bool otherScreenHasFocus, bool coveredByOtherScreen)
    {
        world.Step((float)gameTime.ElapsedGameTime.TotalSeconds);
        this.stewie.Update(gameTime, world);
        this.floor.Update(gameTime, world);
        base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen);
    }

    public override void Draw(GameTime gameTime)
    {
        // TODO: Add your drawing code here
        ScreenManager.SpriteBatch.Begin();

        this.stewie.Draw(gameTime);
        this.floor.Draw(gameTime);
        ScreenManager.SpriteBatch.End();

        base.Draw(gameTime);
    }
}

我的Sprite类

    public class Sprite
{
    private Animation graphicsImage;
    private Body physicsBody;
    //Fixture test  
    //private Fixture fixtureBody;
    private Vector2 _screenCenter;

    private float pixelsPerMeter = 50;  //needed to convert pixels per meter , because the gesture.position is in meters
    public Body PhysicsBody { get { return physicsBody; } }

    public Sprite()
    {
        this.graphicsImage = new Animation();
    }
    /// <summary>
    /// Initialize the sprite sets up position , creates rectangle from bodyfactory 
    /// </summary>
    /// <param name="world"> takes a reference to the worldobject</param>
    public void Initialize(World world, BodyType bodyType,Vector2 position)
    {
        this.graphicsImage.Initialize();

        this.physicsBody = BodyFactory.CreateRectangle(world, this.graphicsImage.Size.X / pixelsPerMeter, this.graphicsImage.Size.Y / pixelsPerMeter, 1f);
        this.graphicsImage.Position = position / pixelsPerMeter;
        this.physicsBody.Position = this.graphicsImage.Position;
        this.physicsBody.BodyType = bodyType;
     //   this.fixtureBody = FixtureFactory.AttachRectangle(this.physicsBody.Position.X / pixelsPerMeter, this.physicsBody.Position.Y / pixelsPerMeter, 3f, new Vector2(100, 100), this.physicsBody);

        //this.physicsBody.Restitution = 0.7f;
        Debug.WriteLine("Initialize Sprite");
        Debug.WriteLine(this.graphicsImage.Position);
    }

    /// <summary>
    /// LoadGraphicsContent for the sprite    call this function in the LoadContent ( initialize also works ) 
    /// </summary>
    /// <param name="spriteBatch">takes a reference to a spritebatch</param>
    /// <param name="texture">takes a reference to texture2D</param>
    public void LoadGraphicsContent(SpriteBatch spriteBatch, Texture2D texture, World world)
    {
        this.graphicsImage.LoadGraphicsContent(spriteBatch, texture);
    }


    /// <summary>
    /// Update sprite for graphicsImage position , and rotation  needs to be called in the main Update function of the game 
    /// </summary>
    /// <param name="gameTime">reference to gameTime</param>
    /// <param name="world">reference to worldobject</param>
    public void Update(GameTime gameTime, World world)
    {
        this.graphicsImage.Update(gameTime);
        this.graphicsImage.Position = this.physicsBody.Position;
        this.graphicsImage.Rotation = this.physicsBody.Rotation;

    }

    /// <summary>
    ///  Draw sprite method needs to be called in the main Draw function of the game
    /// </summary>
    /// <param name="gameTime"></param>
    public void Draw(GameTime gameTime)
    {
        this.graphicsImage.Draw(gameTime);
    } 
}

}

正如我已经说过的那样，我的碰撞是不起作用的。我查看了使用Farseer 3.3的当前样本（就像我一样）。例如，这里是http://farseerphysics.codeplex.com/releases/view/64108，然后是HelloWorld示例。我已经阅读了有关GeomFactory的内容，这些内容正在以前的版本中用于碰撞。然而，随着新版本的Farseer的改变，bodyfactory可以处理大量的东西。那么有谁知道为什么我的碰撞不起作用？

Answer 1

是的，你的定位是关闭的，因为我从使用引擎获得的内容中使用了Meters中的屏幕坐标。这意味着您的屏幕只能是10x16（ish）米（480x800像素），因为这就是微软的屏幕分辨率上限。因此，当你传入16000,1500像素的位置并将其除以50时，你实际上是将身体放在320米和30米处，这对于身体而言在屏幕之外，但是在屏幕上用于绘制功能，因为它认为这些值以像素为单位。

同样从我在他们网站上的HelloWorld示例中看到的，您应该使用64来除以不是50.我不确定为什么这是完全但我猜它是因为64是因子2和计算机喜欢2 lol的因素，所以如果你使用50，你可能会发生一些碰撞事件。

在farseer物理引擎中的碰撞检测3.3

1 个答案: