我正在写一个Snake程序,并试图让它变得如此,吃每一块食物都会增加Snake的长度。取而代之的是食物和一条长度的蛇重新设置了它们的位置。我不知道如何制作,这样(例如),在吃了一种食物后,第一个盒子的前一个位置出现了一个新盒子,蛇就一直在走。提前感谢您提供的任何帮助!
import acm.program.*;
import acm.graphics.*;
import acm.util.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.awt.Component.*;
import java.awt.Color.*;
import acm.program.*;
import acm.graphics.*;
import acm.util.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
public class Board extends GraphicsProgram
{
// constants
private final int
APPLICATION_WIDTH = 300,
APPLICATION_HEIGHT = 300; // application width and height should be equal
private final int ALL_DOTS = 900;
private final int DELAY = 100;
ArrayList<GRect> snakeJoints = new ArrayList<GRect>();
private Enemy enemy;
private int dots, foodX, foodY;
private int randPos = APPLICATION_WIDTH/10 - 1;
private int dotSize = APPLICATION_WIDTH/30;
private boolean right = false;
private boolean left = false;
private boolean up = false;
private boolean down = false;
private boolean gameOver = false;
private GImage ball, food;
private RandomGenerator rand;
private GLabel gameLost;
public void init()
{
setSize(APPLICATION_WIDTH + 3*dotSize, APPLICATION_HEIGHT + 8*dotSize);
addKeyListeners();
rand = new RandomGenerator();
GRect dot = new GRect(dotSize, dotSize);
snakeJoints.add(new GRect(dotSize, dotSize));
snakeJoints.get(0).setFillColor(Color.RED);
snakeJoints.get(0).setFilled(true);
food = new GImage("food.png");
food.setSize(.9 * dotSize, .9 * dotSize);
setBackground(Color.BLACK);
newSquare();
placeFood();
enemy = new Enemy(dotSize);
add(enemy);
enemy.setFillColor(Color.MAGENTA);
enemy.setFilled(true);
enemy.setLocation(rand.nextInt(1, randPos - 3)*dotSize,
rand.nextInt(1, randPos - 3)*dotSize);
}
public void run()
{
while (!gameOver)
{
oneTimeStep();
pause(DELAY);
}
}
public void oneTimeStep()
{
checkLoseCollision();
checkFood();
move();
}
public void newSquare()
{
snakeJoints.add(new GRect(dotSize, dotSize));
snakeJoints.get(0).setFillColor(Color.RED);
snakeJoints.get(0).setFilled(true);
add(snakeJoints.get(0), APPLICATION_WIDTH/2, APPLICATION_HEIGHT/2);
}
public void placeFood()
{
int i = (int) (Math.random() * randPos);
foodX = ((i * dotSize));
i = (int) (Math.random() * randPos);
foodY = ((i * dotSize));
add(food, foodX - dotSize, foodY - dotSize);
}
public void gameLost()
{
gameOver = true;
gameLost = new GLabel("Game Over", APPLICATION_WIDTH/2,
APPLICATION_HEIGHT/2);
gameLost.setColor(Color.BLUE);
add(gameLost);
}
public void checkFood()
{
if (snakeJoints.get(0).getBounds().intersects(food.getBounds()))
{
remove(food);
newSquare();
placeFood();
}
}
public void move()
{
for (int i = snakeJoints.size()-1; i > 0; i--)
{
snakeJoints.get(i).setLocation(snakeJoints.get(i-1).getX(), snakeJoints.get(i-1).getY());
}
if (left)
{
snakeJoints.get(0).move(-dotSize, 0);
}
if (right)
{
snakeJoints.get(0).move(dotSize, 0);
}
if (up)
{
snakeJoints.get(0).move(0, -dotSize);
}
if (down)
{
snakeJoints.get(0).move(0, dotSize);
}
}
public void checkLoseCollision()
{
for (int i = dots; i > 0; i--)
{
if ((i > 4) && (snakeJoints.get(0).getBounds().intersects
(snakeJoints.get(i).getBounds())))
{
gameLost();
}
}
if (snakeJoints.get(0).getY() + dotSize > APPLICATION_HEIGHT || snakeJoints.get(0).getY() < 0)
{
gameLost();
}
if (snakeJoints.get(0).getX() + dotSize > APPLICATION_WIDTH || snakeJoints.get(0).getX() < 0)
{
gameLost();
}
if (snakeJoints.get(0).getBounds().intersects(enemy.getBounds()))
{
gameLost();
}
}
public void keyPressed(KeyEvent e)
{
int key = e.getKeyCode();
if (key == KeyEvent.VK_LEFT)
{
left = true;
right = false;
up = false;
down = false;
}
if (key == KeyEvent.VK_RIGHT)
{
right = true;
left = false;
up = false;
down = false;
}
if (key == KeyEvent.VK_UP)
{
up = true;
down = false;
right = false;
left = false;
}
if (key == KeyEvent.VK_DOWN)
{
down = true;
up = false;
right = false;
left = false;
}
}
}
public void newSquare()
{
snakeJoints.add(new GRect(dotSize, dotSize));
snakeJoints.get(0).setFillColor(Color.RED);
snakeJoints.get(0).setFilled(true);
**add(snakeJoints.get(0), APPLICATION_WIDTH/2, APPLICATION_HEIGHT/2);**
}
我相信你的最后一行(添加(snakeJoints.get(0),APPLICATION_WIDTH/2,APPLICATION _HEIGHT/2))将你的蛇设置在中心。您的调用checkFood调用newSquare,而不是在蛇的末端添加新的正方形,将其设置为应用程序窗口的中心(dimensions/2)。
请注意,如果你的蛇头图形与其他部分相同,你基本上可以把食物变成正方形,然后做成蛇的新头(效果是一样的——蛇变长了)。
在这段代码中,您有几个问题:
public void newSquare()
{
snakeJoints.add(new GRect(dotSize, dotSize));
snakeJoints.get(0).setFillColor(Color.RED);
snakeJoints.get(0).setFilled(true);
add(snakeJoints.get(0), APPLICATION_WIDTH/2, APPLICATION_HEIGHT/2);
}
snakeJoins.add()
会将新关节添加到列表的末尾,但随后将继续操作第一个元素。此外,您还可以将新联接的坐标设置到屏幕中间。
我认为你应该做的是,为了正确地生长你的蛇,在你移动它之前,检查你的蛇何时会吃掉食物。这样你就可以制作它,使食物矩形成为你的蛇的第一个关节,你不再需要在这个迭代中移动它。
编辑:一些思考的食物(伪代码):
public void move()
{
for (int i = snakeJoints.size()-1; i > 0; i--)
{
snakeJoints.get(i).setLocation(snakeJoints.get(i-1).getX(), snakeJoints.get(i-1).getY());
}
GRect newPosition = new GRect(snakeJoints.get(0).getBounds());
if (left)
{
newPostition.setLocation(newPostition.getX()-dotSize, newPosition.getY());
}
if (right) {//etc
}
if (intersectsWithFood(newLocation) {
//repaint food as snake joint
food.setFillColor(Color.RED);
food.setFilled(true);
snakeJoints.addFirst(food); //add food as a joint
createFood();//create another food
} else {
snakeJoints.get(0).setLocation(newLocation.getX(), newLocation.getY());
}
}