关于J2ME--MIDP1.0中的碰撞检测

/**
 * 检测一个特定点是否进入一个Actor内
 * @param px 特定点的x坐标.
 * @param py 特定点的y坐标
 * @return
 如果特定点进入Actor范围内，那么返回true,否则为false;
 */
public boolean isCollidingWith(int px, int py) {
    if (px >= getX() && px <= (getX() + getActorWidth()) &&
        py >= getY() && py <= (getY() + getActorHeight())) {
        return true;
    }
    return false;
}

/**
 * 检测一个Actor对象是否碰上了当前的Actor对象。
 * @param another 另一个Actor对象
 * @return 如果another和当前对象发生碰撞，则返回true,否则为false.
 */
public boolean isCollidingWith(Actor another) {
// check if any of our corners lie inside the other actor's
// bounding rectangle
    if (isCollidingWith(another.getX(), another.getY()) ||
        isCollidingWith(another.getX() + another.getActorWidth(), another.getY()) ||
        isCollidingWith(another.getX(), another.getY() + another.getActorHeight()) ||
        isCollidingWith(another.getX() + another.getActorWidth(),
                        another.getY() + another.getActorHeight())) {
        return true;
    } else {
        return false;
    }
}

/**
 * 较为通用的矩形碰撞检测方法
 * @param ax a矩形左上角x坐标
 * @param ay a矩形左上角y坐标
 * @param aw a矩形宽度
 * @param ah a矩形高度
 * @param bx b矩形左上角x坐标
 * @param by b矩形左上角y坐标
 * @param bw b矩形宽度
 * @param bh b矩形高度
 * @return
 */
public static final boolean isIntersectingRect(int ax, int ay, int aw,
                                               int ah, int bx, int by, int bw,
                                               int bh) {
    if (by + bh < ay || // is the bottom of b above the top of a?
        by > ay + ah || // is the top of b below bottom of a?
        bx + bw < ax || // is the right of b to the left of a?
        bx > ax + aw) { // is the left of b to the right of a?
        return false;
    }
    return true;
}