初学Java问题 - "突围"游戏.我的下一步是什么？

Question

这是我关于SO的第一篇文章!

我自己一直在通过斯坦福大学的"编程方法论"课程工作几周,该课程是用java编程的简介.到目前为止,我一直在做所有的程序,没有什么困难,以最小的难度研究我需要的东西.

现在,我所拥有的只是一组砖块和一个我能够从墙上反弹的球.目前球没有做任何事情,只是在画布中反弹并穿过砖块.
涉及很多步骤,其他我非常肯定我可以照顾.我遇到困难的是......

1)让球从砖块上弹开.
2)当球从球上反弹时,让砖块消失.

我一直在使用的一些资源 -
使用ACM图形包
斯坦福PDF和分配指南

我想我的问题是.为了能够解决上面列出的问题,我需要了解什么.在其中一个讲座中,教授谈到使用"getElementAt()"但我真的不明白这种方法是如何工作的,或者我怎么能用它来让我的球从砖块上反弹然后再让它们消失.

我到目前为止编写的代码 -

/*
 * File: Breakout.java
 * -------------------
 * Name: Sandi
 * Section Leader: I'm learning this online
 *
 * This file will eventually implement the game of Breakout.
 */

import acm.graphics.*;
import acm.program.*;
import acm.util.*;

import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class Breakout extends GraphicsProgram {

    /** Width and height of application window in pixels */
    public static final int APPLICATION_WIDTH = 400;
    public static final int APPLICATION_HEIGHT = 600;

    /** Dimensions of game board (usually the same) */
    private static final int WIDTH = APPLICATION_WIDTH;
    private static final int HEIGHT = APPLICATION_HEIGHT;

    /** Dimensions of the paddle */
    private static final int PADDLE_WIDTH = 60;
    private static final int PADDLE_HEIGHT = 10;

    /** Offset of the paddle up from the bottom */
    private static final int PADDLE_Y_OFFSET = 30;

    /** Number of bricks per row */
    private static final int NBRICKS_PER_ROW = 10;

    /** Number of rows of bricks */
    private static final int NBRICK_ROWS = 10;

    /** Separation between bricks */
    private static final int BRICK_SEP = 4;

    /** Width of a brick */
    private static final int BRICK_WIDTH = (WIDTH - (NBRICKS_PER_ROW - 1)
            * BRICK_SEP)
            / NBRICKS_PER_ROW;

    /** Height of a brick */
    private static final int BRICK_HEIGHT = 8;

    /** Radius of the ball in pixels */
    private static final int BALL_RADIUS = 10;

    /** Offset of the top brick row from the top */
    private static final int BRICK_Y_OFFSET = 70;

    /** Number of turns */
    private static final int NTURNS = 3;

    /* Method: run() */
    /** Runs the Breakout program. */

    public void run() {
        addBricks();
        addBall();

        //velocity of the ball's x and y
        ballVX = 1;
        ballVY = 2;

        while (true) {
            moveBall();
            pause(10);
        }
    }

    private void addBricks() {
        int startY = BRICK_Y_OFFSET;
        GRect brick;

        for (int i = 0; i < NBRICK_ROWS; i++) {

            int startX = BRICK_SEP;

            for (int j = 0; j < NBRICKS_PER_ROW; j++) {
                brick = new GRect(startX, startY, BRICK_WIDTH, BRICK_HEIGHT);
                add(brick);

                colorBricks(brick, Color.RED, 0, 1);
                colorBricks(brick, Color.ORANGE, 2, 3);
                colorBricks(brick, Color.YELLOW, 4, 5);
                colorBricks(brick, Color.GREEN, 6, 7);
                colorBricks(brick, Color.CYAN, 8, 9);

                startX += BRICK_WIDTH + BRICK_SEP;
            }

            startY += BRICK_HEIGHT + BRICK_SEP;
        }
    }

    private void colorBricks(GRect brick, Color color, int fromRowNumber,
            int toRowNumber) {
        //this will make it so that if the bricks are between two y coordinates
        //then the method will set it to a certain color and color it.
        if (brick.getY() >= BRICK_Y_OFFSET + fromRowNumber
                * (BRICK_HEIGHT + BRICK_SEP)
                && brick.getY() <= BRICK_Y_OFFSET + toRowNumber
                        * (BRICK_HEIGHT + BRICK_SEP)) {
            brick.setColor(color);
            brick.setFilled(true);
        }
    }

    private void addBall() {
        ball = new GOval(getWidth() / 2, getHeight() / 2, BALL_RADIUS,
                BALL_RADIUS);
        ball.setFilled(true);
        add(ball);
    }

    private void moveBall() {
        double borderX = ball.getX();
        double borderY = ball.getY();

        if (borderX == 0 || borderX == getWidth() - BALL_RADIUS) {
            ballVX = -ballVX;
        }
        if (borderY == 0 || borderY == getHeight() - BALL_RADIUS) {
            ballVY = -ballVY;
        }

        ball.move(ballVX, ballVY);
    }

    private GOval ball;
    private double ballVX;
    private double ballVY;
}

多谢你们!

Answer 1

以一种可以轻松检查某个坐标是否存在砖块的方式对砖块进行索引。

当你创建一块砖块时，你将它添加到容器中，然后你就失去了它。您没有可以用来与当前球位置进行比较的未来参考。

根据您的设计，我相信您应该通过二维数组来完成此操作。创建砖块时，还将GRect对象放入二维数组中。一个维度应该是行，另一个维度应该是列。然后您将能够使用该数组通过 x 和 y 坐标访问这些砖块。（这是您需要执行的操作来检测反弹。）

当球移动时，就像您检测到它从墙壁弹起一样，检查球的位置是否使其与砖块可能所在的位置接壤。如果确实如此，从任何方向，然后通过查看阵列来检查砖块是否确实存在。如果那里有砖块，弹起球并移走砖块。还要确保将数组中的该位置设置为null指示砖块已消失。

然后你也有你的胜利条件......当数组的所有元素都被设置为空时。