javasprite.txt

来自「《24小时教会你游戏编程》上的源码」· 文本 代码 · 共 243 行

public class Sprite {
  // Sprite action flags
  public static final int SA_KILL = 0,
                          SA_RESTOREPOS = 1,
                          SA_ADDSPRITE = 2;
  // Bounds actions
  public static final int BA_STOP = 0,
                          BA_WRAP = 1,
                          BA_BOUNCE = 2,
                          BA_DIE = 3;
  protected Component     component;
  protected Image[]       image;
  protected int           frame,
                          frameInc,
                          frameDelay,
                          frameTrigger;
  protected Rectangle     position,
                          collision;
  protected int           zOrder;
  protected Point         velocity;
  protected Rectangle     bounds;
  protected int           boundsAction;
  protected boolean       hidden = false;

  public Sprite(Component comp, Image img, Point pos, Point vel, int z,
    int ba) {
    component = comp;
    image = new Image[1];
    image[0] = img;
    setPosition(new Rectangle(pos.x, pos.y, img.getWidth(comp),
      img.getHeight(comp)));
    setVelocity(vel);
    frame = 0;
    frameInc = 0;
    frameDelay = frameTrigger = 0;
    zOrder = z;
    bounds = new Rectangle(0, 0, comp.size().width, comp.size().height);
    boundsAction = ba;
  }

  public Sprite(Component comp, Image[] img, int f, int fi, int fd,
    Point pos, Point vel, int z, int ba) {
    component = comp;
    image = img;
    setPosition(new Rectangle(pos.x, pos.y, img[f].getWidth(comp),
      img[f].getHeight(comp)));
    setVelocity(vel);
    frame = f;
    frameInc = fi;
    frameDelay = frameTrigger = fd;
    zOrder = z;
    bounds = new Rectangle(0, 0, comp.size().width, comp.size().height);
    boundsAction = ba;
  }

  public Image[] getImage() {
    return image;
  }

  public void setImage(Image[] img) {
    image = img;
  }

  public int getFrameInc() {
    return frameInc;
  }

  public void setFrameInc(int fi) {
    frameInc = fi;
  }

  public int getFrame() {
    return frame;
  }

  protected void incFrame() {
    if ((frameDelay > 0) && (--frameTrigger <= 0)) {
      // Reset the frame trigger
      frameTrigger = frameDelay;

      // Increment the frame
      frame += frameInc;
      if (frame >= image.length)
        frame = 0;
      else if (frame < 0)
        frame = image.length - 1;
    }
  }

  public Rectangle getPosition() {
    return position;
  }

  void setPosition(Rectangle pos) {
    position = pos;
    setCollision();
  }

  public void setPosition(Point pos) {
    position.move(pos.x, pos.y);
    setCollision();
  }

  protected void setCollision() {
    collision = position;
  }

  protected Rectangle getCollision() {
    return collision;
  }

  public int getZOrder() {
    return zOrder;
  }

  public Point getVelocity() {
    return velocity;
  }

  public void setVelocity(Point vel)
  { 
    velocity = vel;
  }

  public Rectangle getBounds() {
    return bounds;
  }

  public void setBounds(Rectangle b) {
    bounds = b;
  }

  public void show() {
    hidden = false;
  }
  
  public void hide() {
    hidden = true;
  }

  boolean isPointInside(Point pt) {
    return position.inside(pt.x, pt.y);
  }

  public BitSet update() {
    BitSet action = new BitSet();

    // Increment the frame
    incFrame();

    // Update the position
    Point pos = new Point(position.x, position.y);
    pos.translate(velocity.x, velocity.y);

    // Check the bounds
    // Wrap?
    if (boundsAction == Sprite.BA_WRAP) {
      if ((pos.x + position.width) < bounds.x)
        pos.x = bounds.x + bounds.width;
      else if (pos.x > (bounds.x + bounds.width))
        pos.x = bounds.x - position.width;
      if ((pos.y + position.height) < bounds.y)
        pos.y = bounds.y + bounds.height;
      else if (pos.y > (bounds.y + bounds.height))
        pos.y = bounds.y - position.height;
    }
    // Bounce?
    else if (boundsAction == Sprite.BA_BOUNCE) {
      boolean bounce = false;
      Point   vel = new Point(velocity.x, velocity.y);
      if (pos.x < bounds.x) {
        bounce = true;
        pos.x = bounds.x;
        vel.x = -vel.x;
      }
      else if ((pos.x + position.width) >
        (bounds.x + bounds.width)) {
        bounce = true;
        pos.x = bounds.x + bounds.width - position.width;
        vel.x = -vel.x;
      }
      if (pos.y < bounds.y) {
        bounce = true;
        pos.y = bounds.y;
        vel.y = -vel.y;
      }
      else if ((pos.y + position.height) >
        (bounds.y + bounds.height)) {
        bounce = true;
        pos.y = bounds.y + bounds.height - position.height;
        vel.y = -vel.y;
      }
      if (bounce)
        setVelocity(vel);
    }
    // Die?
    else if (boundsAction == Sprite.BA_DIE) {
      if ((pos.x + position.width) < bounds.x ||
        pos.x > bounds.width ||
        (pos.y + position.height) < bounds.y ||
        pos.y > bounds.height) {
        action.set(Sprite.SA_KILL);
        return action;
      }
    }
    // Stop (default)
    else {
      if (pos.x  < bounds.x ||
        pos.x > (bounds.x + bounds.width - position.width)) {
        pos.x = Math.max(bounds.x, Math.min(pos.x,
          bounds.x + bounds.width - position.width));
        setVelocity(new Point(0, 0));
      }
      if (pos.y  < bounds.y ||
        pos.y > (bounds.y + bounds.height - position.height)) {
        pos.y = Math.max(bounds.y, Math.min(pos.y,
          bounds.y + bounds.height - position.height));
        setVelocity(new Point(0, 0));
      }
    }
    setPosition(pos);

    return action;
  }

  public void draw(Graphics g) {
    // Draw the current frame
    if (!hidden)
      g.drawImage(image[frame], position.x, position.y, component);
  }

  protected Sprite addSprite(BitSet action) {
    return null;
  }

  protected boolean testCollision(Sprite test) {
    // Check for collision with another sprite
    if (test != this)
      return collision.intersects(test.getCollision());
    return false;
  }
}