蛇头与蛇身体碰撞问题Java（加工）

Question

我已经为大学项目开始了一个Snake游戏，我目前遇到的问题是，存储在数组中的主体的第一段与头部位于同一位置。我不太清楚如何抵消身体第一段的位置，因此它与头部的位置不同。

当我在身体和头部之间创建碰撞检测时我注意到了这一点，并且由于第一段与头部位于同一位置而无法正常工作。

的 MainApp.java

import processing.core.*;
import java.awt.*;

/**
 * Created by Wills on 25/05/2018.
 */
public class MainApp extends PApplet{
    Snake snake;
    Food food;
    public static void main(String[] args){
        PApplet.main("MainApp", args);
    }
    int screenSize = 800;
    int scale = 20;
    public void settings(){
        size(screenSize,screenSize);
        snake = new Snake(width/2, height/2, 0, 1, scale, screenSize );
        food = new Food(screenSize, scale);
    }
    public void setup(){
        frameRate(10);
        rect(food.getX(), food.getY(), scale, scale);
    }
    public void draw() {
        background(0);
        snake.update();
        fill(255);
        rect(snake.getX(), snake.getY(), snake.getScale(), snake.getScale());
        if(snake.getX()  == food.getX() && snake.getY() == food.getY()){
            snake.eat();
        }
        for(Point p: snake.getBody()){
            if(food.getX() == p.getX() && food.getY() == p.getY()){
                food.rePos();
            }
            rect((float)p.getX(), (float)p.getY(), snake.getScale(), snake.getScale());
        }
        fill(255,0,0);
        rect(food.getX(), food.getY(), scale, scale);
    }
    public void mouseClicked(){
        snake.eat();
        snake.eat();
        snake.eat();
        snake.eat();
    }
    public void keyPressed(){
        if(key == 'a'){
            snake.setDirection(-1, 0);
        }
        if(key == 'd'){
            snake.setDirection(1, 0);
        }
        if(key == 'w'){
            snake.setDirection(0, -1);
        }
        if(key == 's'){
            snake.setDirection(0, 1);
        }
    }
}

的 Snake.java

import processing.core.PApplet;

import java.awt.*;
import java.util.ArrayList;

/**
 * Created by Wills on 25/05/2018.
 */
public class Snake extends PApplet{
    int x, y, yspeed, xspeed, scale;
    int score;
    int screenSize;
    ArrayList<Point> body;
    public Snake(int x, int y, int xspeed, int yspeed, int scale, int screenSize){
        body = new ArrayList<Point>();
        this.x = x;
        this.y = y;
        this.xspeed = xspeed;
        this.yspeed = yspeed;
        this.scale = scale;
        this.screenSize = screenSize;
    }
    public int getX(){
        return x;
    }
    public int getY() {
        return y;
    }
    public void setDirection(int x, int y){
        this.xspeed = x;
        this.yspeed = y;
    }
    public float getScale(){
        return scale;
    }
    void update(){
        x = constrain(x + xspeed * scale,0, screenSize - scale);
        y =constrain(y + yspeed * scale,0, screenSize - scale);
        body.add(0, new Point(x, y));
        body.remove(score);
    }
    void eat(){
        body.add(new Point(x,y));
        score ++;
        System.out.println(score);

    }
    void kill(){
        score = 0;
        x = screenSize/2;
        y = screenSize/2;
    }
    ArrayList<Point> getBody(){
        return body;
    }

}

的 Food.java

import processing.core.PApplet;

import java.awt.*;
import java.util.ArrayList;

/**
 * Created by Wills on 25/05/2018.
 */
public class Food extends PApplet{
    float screenSize;
    int scale, x, y;
    Food(int screenSize, int scale){
        this.scale = scale;
        this.screenSize = screenSize;
        generate();
    }
    float getX(){
        return x;
    }
    float getY(){
        return y;
    }
    public void rePos() {
        generate();
    }
    private void generate(){
        x = floor(random(0, scale));
        y = floor(random(0, scale));
        x = (int) map(x, 0, scale, 0, screenSize);
        y = (int) map(y, 0, scale, 0, screenSize);
    }
}

非常感谢任何帮助！