c# - 无法在 XNA 中绘制超过正方形的图像

Question

我正在制作乒乓球游戏。在调试时，我一直在使用一个简单的 44 x 44 .png 红色方 block 作为我的球。游戏在这个方 block 上运行良好。

当我尝试用除正方形以外的任何东西替换纹理时，我在屏幕上看不到绘制的球，而且我不明白为什么。我在 photoshop 中使我的图像大小完全相同，并使用 .PNG 或 .JPG 并获得相同的结果，但我无法弄清楚我的生活。您认为可能导致此问题的原因是什么？

我在下面的文字中留下了我的球的代码。 GameplayScreen 正在调用我的球的更新和绘制方法(使用 MS 的 GSM 示例)。

    public class Ball : IGameEntity
{
    #region Fields

    private Random rand;                // Random var
    private Texture2D texture;          // Texture for the ball
    private double direction;           // Directon the ball is traveling in                
    private bool isVisible;
    private bool hasHitLeftBat;         // Checked to see if the ball and bat have just collided
    private bool hasHitRightBat;        // Checked to see if the ball and bat have just collided
    private Vector2 ballPosition, resetBallPos, oldBallPos;
    private Rectangle ballRect;
    public float Speed;
    private SpriteBatch spriteBatch;    // Spritebatch
    private bool isBallStopped;
    private Vector2 origin;             // Locate the mid-point of the ball
    public float RotationAngle;
    private AIBat rightBat;             // Player's Bad
    private Bat leftBat;                // AI Bat
    private float ballRelativePos;
    private Rectangle rectangle3;       // Used to draw the collison rectangle
    private Texture2D blank;            // Texture to be drawn on the collision rectangle

    GameplayScreen gameplayScreen;      // Creates an instance of the GameplayScreen
    Game1 gameInstance;                 // Creates an instance of the Game1 class
    int selectedStage;                  // Pass this into GameplayScreen for selecting easy, medium, or hard


    #endregion

    #region Constructors and Destructors

    /// <summary>
    /// Constructor for the ball
    /// </summary>
    public Ball(ContentManager contentManager, Vector2 ScreenSize, Bat bat, AIBat aiBat)
    {
        Speed = 15f;
        texture = contentManager.Load<Texture2D>(@"gfx/balls/redBall");
        direction = 0;
        ballRect = new Rectangle(0, 0, texture.Width /2, texture.Height /2);
        resetBallPos = new Vector2(ScreenSize.X / 2 + origin.X, ScreenSize.Y / 2 + origin.Y);
        ballPosition = resetBallPos;
        rand = new Random();
        isVisible = true;
        origin = new Vector2(texture.Width / 2, texture.Height / 2);
        leftBat = bat; // Creates a new instance of leftBat so that I can access Position.X/Y for LeftBatPatcicles()
        rightBat = aiBat;// Creates a new instance of leftBat so that  can access Position.X/Y for RightBatPatcicles()
        gameplayScreen = new GameplayScreen(null, selectedStage);
        gameInstance = new Game1();
        Rectangle rectangle3 = new Rectangle();
        blank = contentManager.Load<Texture2D>(@"gfx/blank");               

        //   pes = new ParticleEmitterService(game);
    }

    public Ball(Bat myBat)
    {
        leftBat = myBat;          // this assigns and instantiates the member bat
                                  // with myBat which was passed from the constructor
    }

    #endregion

    #region Methods

    /// <summary>
    /// Draws the ball on the screen
    /// </summary>
    public void Draw(SpriteBatch spriteBatch)
    {
        if (isVisible)
        {
            // Draws the rotaing ball
            spriteBatch.Draw(texture, ballPosition, ballRect, Color.White,
                              RotationAngle, origin, .0f, SpriteEffects.None, 0);

            spriteBatch.Draw(blank, rectangle3, Color.LightCoral);
        }
    }

    /// <summary>
    /// Updates position of the ball. Used in Update() for GameplayScreen.
    /// </summary>
    public void UpdatePosition(GameTime gameTime)
    {
        ballRect.X = (int)ballPosition.X;
        ballRect.Y = (int)ballPosition.Y;
        oldBallPos.X = ballPosition.X;
        oldBallPos.Y = ballPosition.Y;

        ballPosition.X += Speed * ((float)Math.Cos(direction));

        ballPosition.Y += Speed * ((float)Math.Sin(direction));
        bool collided = CheckWallHit();


        // Stops the issue where ball was oscillating on the ceiling or floor
        if (collided)
        {
            ballPosition.X = oldBallPos.X + Speed * (float)1.5 * (float)Math.Cos(direction);
            ballPosition.Y = oldBallPos.Y + Speed * (float)Math.Sin(direction);
        }

        // As long as the ball is to the right of the back, check for an update
        if (ballPosition.X > leftBat.BatPosition.X)
        {
            // When the ball and bat collide, draw the rectangle where they intersect
            BatCollisionRectLeft();
        }

        // As longas the ball is to the left of the back, check for an update
        if (ballPosition.X < rightBat.BatPosition.X)
        {   // When the ball and bat collide, draw the rectangle where they intersec
            BatCollisionRectRight();
        }

        // The time since Update was called last.
        float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;

        // Rotation for the ball
        RotationAngle += elapsed;
        float circle = MathHelper.Pi * 2;
        RotationAngle = RotationAngle % circle;

        //      base.Update(gameTime);
        gameInstance.update();

    }


    /// <summary>
    /// Checks for the current direction of the ball
    /// </summary>
    public double GetDirection()
    {
        return direction;
    }

    /// <summary>
    /// Checks for the current position of the ball
    /// </summary>
    public Vector2 GetPosition()
    {
        return ballPosition;
    }

    /// <summary>
    /// Checks for the current size of the ball (for the powerups)
    /// </summary>
    public Rectangle GetSize()
    {
        return ballRect;
    }



    /// <summary>
    /// Checks to see if ball went out of bounds, and triggers warp sfx. Used in GameplayScreen.
    /// </summary>
    public void OutOfBounds()
    {
        AudioManager.Instance.PlaySoundEffect("Muzzle_shot");
    }

    /// <summary>
    /// Speed for the ball when Speedball powerup is activated
    /// </summary>
    public void PowerupSpeed()
    {
        Speed += 20.0f;
    }

    /// <summary>
    /// Check for where to reset the ball after each point is scored
    /// </summary>
    public void Reset(bool left)
    {
        if (left)
        {
            direction = 0;
        }
        else
        {
            direction = Math.PI;
        }

        ballPosition = resetBallPos; // Resets the ball to the center of the screen
        isVisible = true;
        Speed = 15f; // Returns the ball back to the default speed, in case the speedBall was active
        if (rand.Next(2) == 0)
        {
            direction += MathHelper.ToRadians(rand.Next(30));
        }
        else
        {
            direction -= MathHelper.ToRadians(rand.Next(30));
        }
    }

    /// <summary>
    /// Shrinks the ball when the ShrinkBall powerup is activated
    /// </summary>
    public void ShrinkBall()
    {
        ballRect = new Rectangle(0, 0, texture.Width / 2, texture.Height / 2);
    }

    /// <summary>
    /// Stops the ball each time it is reset. Ex: Between points / rounds
    /// </summary>
    public void Stop()
    {
        isVisible = true;
        Speed = 0;
        isBallStopped = true;
    }

    /// <summary>
    /// Checks for collision with the ceiling or floor. 2*Math.pi = 360 degrees
    /// </summary>
    private bool CheckWallHit()
    {
        while (direction > 2 * Math.PI)
        {
            direction -= 2 * Math.PI;
            return true;
        }

        while (direction < 0)
        {
            direction += 2 * Math.PI;
            return true;
        }

        if (ballPosition.Y <= 0 || (ballPosition.Y > resetBallPos.Y * 2 - ballRect.Height))
        {
            direction = 2 * Math.PI - direction;
            return true;
        }
        return true;
    }

    /// <summary>
    /// Used to determine the location where the particles will initialize when the ball and bat collide
    /// </summary>
    private void BatCollisionRectLeft()
    {
        // For the left bat
        if (ballRect.Intersects(leftBat.batRect))
        {
            rectangle3 = Rectangle.Intersect(ballRect, leftBat.batRect);
        }
    }

    /// <summary>
    ///Checks for collision of Right Bat
    /// </summary>
    private void BatCollisionRectRight()
    {
        // for the right bat
        if (ballRect.Intersects(rightBat.batRect))
        {
            rectangle3 = Rectangle.Intersect(ballRect, rightBat.batRect); ;
        }
    }

Answer 1

我注意到 2 件事，我不认为你想在调用时将矩形尺寸减半

ballRect = new Rectangle(0, 0, texture.Width /2, texture.Height /2);

此外，您在球的顶部绘制了这个空白 Sprite ，因此如果它们重叠，您将看不到球，但如果是这样的话我不知道为什么它与广场一起工作。