如何在2D javafx游戏中计算碰撞标志

Question

我最近开始研究2D街机游戏引擎。它是用java编写的，使用javafx而不是swing。目前，我已经能够模拟物体的重力并移动它们。我想在我的引擎中添加冲突。一个例子是：

框（对象A）向东滑向框（对象B）。当对象A与对象B发生碰撞时，我想检测对象A的东侧是否碰到了什么。

我一直试图让这个工作好几天了。目前我的代码在某些时候有效。它在水平碰撞中运作良好。

我的方法是检测物体的哪一侧相撞。

public Rectangle2D getBoundary() {
    return new Rectangle2D(getX(), getY(), image.getWidth(), image.getHeight());
}

public CollisionFlag getCollisionFlag(ArrayList<GameObject> objects) {
    for (GameObject object : objects) {
        if (object.getBoundary().intersects(this.getBoundary())) {
            if (this.getBoundary().getMaxY() > object.getBoundary().getMaxY()) {
                // ball under object, means my ball getY() is in the object
                if (this.getX() < object.getX()
                        || (this.getX() >= object.getX() && this.getX() <= object.getBoundary().getMaxX())) {
                    // ball is somewhere inside objects x
                    return CollisionFlag.NORTH;
                }
            } else if (this.getY() < object.getY()) {
                // ball above object, means my ball getMaxY() is in object
                if (this.getX() < object.getX()
                        || (this.getX() >= object.getX() && this.getX() <= object.getBoundary().getMaxX())) {
                    return CollisionFlag.SOUTH;
                }
            } else if (this.getX() < object.getX()) {
                // ball to the left of object, means my ball getMaxX() is in
                // object
                if (this.getY() < object.getY()
                        || (this.getY() <= object.getBoundary().getMaxY() && this.getY() >= object.getY())) {
                    return CollisionFlag.EAST;
                }
            } else if (this.getBoundary().getMaxX() > object.getBoundary().getMaxX()) {
                // ball to the right of object, means my ball getX() is in
                // object
                if (this.getY() < object.getY()
                        || (this.getY() <= object.getBoundary().getMaxY() && this.getY() >= object.getY())) {
                    return CollisionFlag.WEST;
                }
            }
        }
    }
    return CollisionFlag.NONE;
}

这是我的完整GameObject类。

    package org.bautista.ag.api.objects;

import java.util.ArrayList;

import org.bautista.ag.api.GameEngine;
import org.bautista.ag.api.locatable.CollisionFlag;
import org.bautista.ag.api.locatable.Position;

import javafx.geometry.Rectangle2D;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;

public abstract class GameObject extends ImageView {

    private final Image image;
    private final boolean movable;
    private double xVelocity;
    private double yVelocity;
    private Position position;

    public GameObject(final Image image, final Position position, final boolean movable) {
        super(image);
        this.image = image;
        this.movable = movable;
        this.position = position;
        reposition(position);
    }

    public Rectangle2D getBoundary() {
        return new Rectangle2D(getX(), getY(), image.getWidth(), image.getHeight());
    }

    public CollisionFlag getCollisionFlag(ArrayList<GameObject> objects) {
        for (GameObject object : objects) {
            if (object.getBoundary().intersects(this.getBoundary())) {
                if (this.getBoundary().getMaxY() > object.getBoundary().getMaxY()) {
                    // ball under object, means my ball getY() is in the object
                    if (this.getX() < object.getX()
                            || (this.getX() >= object.getX() && this.getX() <= object.getBoundary().getMaxX())) {
                        // ball is somewhere inside objects x
                        return CollisionFlag.NORTH;
                    }
                } else if (this.getY() < object.getY()) {
                    // ball above object, means my ball getMaxY() is in object
                    if (this.getX() < object.getX()
                            || (this.getX() >= object.getX() && this.getX() <= object.getBoundary().getMaxX())) {
                        return CollisionFlag.SOUTH;
                    }
                } else if (this.getX() < object.getX()) {
                    // ball to the left of object, means my ball getMaxX() is in
                    // object
                    if (this.getY() < object.getY()
                            || (this.getY() <= object.getBoundary().getMaxY() && this.getY() >= object.getY())) {
                        return CollisionFlag.EAST;
                    }
                } else if (this.getBoundary().getMaxX() > object.getBoundary().getMaxX()) {
                    // ball to the right of object, means my ball getX() is in
                    // object
                    if (this.getY() < object.getY()
                            || (this.getY() <= object.getBoundary().getMaxY() && this.getY() >= object.getY())) {
                        return CollisionFlag.WEST;
                    }
                }
            }
        }
        return CollisionFlag.NONE;
    }

    public Position getPosition() {
        return position;
    }

    public double getXVelocity() {
        return xVelocity;
    }

    public double getYVelocity() {
        return yVelocity;
    }

    public boolean intersects(final GameObject gameObject) {
        return gameObject.getBoundary().intersects(getBoundary())
                && (gameObject.getPosition().getZ() == getPosition().getZ());
    }

    public boolean isElevated() {
        return getBoundary().getMaxY() < GameEngine.getInstance().getBackground().getHeight();
    }

    public boolean isMovable() {
        return movable;
    }

    public boolean isMoving() {
        return xVelocity != 0 || yVelocity != 0;
    }

    public void reposition(final double x, final double y, final double z) {
        reposition(new Position(x, y, z));
    }

    public void reposition(final Position position) {
        this.position = position;
        setX(position.getX());
        setY(position.getY());
    }

    public void setXVelocity(final double xVelocity) {
        this.xVelocity = xVelocity;
    }

    public void setYVelocity(final double yVelocity) {
        this.yVelocity = yVelocity;
    }

    public void update() {
        updateLocation();
    }

    private void updateLocation() {
        if (movable) {
            reposition((getX() + xVelocity), (getY() - yVelocity), position.getZ());
        }
    }

}