我的子弹出现在错误的地方

Question

在我的游戏中，玩家可以使用方向键旋转。根据玩家旋转的角度，当子弹发射时，它会朝着玩家面对的方向行进。

该部分有效，但是，子弹在错误的位置生成。下面是两张显示产卵差异的图片。在第一张图片中，子弹在红点上生成。但是，旋转时圆点不会相应移动，这会阻止子弹正确生成。

注意：红点只是为了视觉效果（基于子弹的生成坐标）

the bullet spawns correctly when facing upwards

the bullet spawns incorrectly when facing every other direction

相关代码如下：

主要的KeyListener：

if (e.getKeyCode() == KeyEvent.VK_SPACE) {
                //Creates bullets when the spacebar is pressed, as long as the user is not exceeding 3 at a time
                if(player.amountOfBullets() >= 0 && player.amountOfBullets() < 10)
                {
                player.setNB(player.getGunX(), player.getGunY(), player.getAngle());
                }
}

玩家：

public class Player {
private BufferedImage spriteSheet;

private double x;
private double y;
private int height;
private int width;

private int gunX;
private int gunY;


private BufferedImage[] sprites = new BufferedImage[13];
private BufferedImage currentImg;
private int frame;
private double angle = 0;

private ArrayList<Bullet> nb = new ArrayList<Bullet>(10); 

public Player(){
    try { 
        spriteSheet = ImageIO.read(getClass().getResource("/Sprites.png"));
    } catch (IOException e) { 
        System.err.println("Sprites3.png could not be found");
    }

    for (int i = 0; i < sprites.length; i++){
        sprites[i] = grabImage(1, i+1, 100);
    }
    currentImg = sprites[0];
    x = 10;
    y = 10;
    width = currentImg.getWidth();
    height = currentImg.getHeight();

    gunX = (int) x + width - 15;
    gunY = (int) y;
}

public BufferedImage grabImage(int col, int row, int length){
    BufferedImage img = spriteSheet.getSubimage(((col-1) * length), ((row-1) * length), length, length);
    return img;
}

public void paint(Graphics2D g2d){

    for(int i = 0; i < nb.size(); i++)
    {
        if(nb.get(i).getTime()*10 >= 15)
        {
            nb.set(0, null);
            nb.remove(nb.get(0));//removes bullets based on the time they are in game
        }
    }

    double rotationRequired = Math.toRadians (angle);
    double locationX = currentImg.getWidth() / 2;
    double locationY = currentImg.getHeight() / 2;
    AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
    AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);

    for (int i = 0; i < nb.size(); i++)
    {
        nb.get(i).move();//moves the bullets
        nb.get(i).paint(g2d);
    }

    // Drawing the rotated image at the required drawing locations
    g2d.drawImage(op.filter(currentImg, null), (int)x, (int)y, null);
    //g2d.fillOval(x, y, 10, 10);
    g2d.setColor(Color.RED);
    int x = (int) this.x;
    int y = (int) this.y;
    g2d.fillOval(gunX, gunY, 10, 10);
}

public void update(){
    currentImg = sprites[frame];
}

public void move(double xM, double yM){
    if (yM == 5) xM = -5;
    else xM = 5;
    x += xM * Math.sin(Math.toRadians(angle));
    y += yM * Math.cos(Math.toRadians(angle));

    gunY += yM * Math.cos(Math.toRadians(angle));
    gunX += xM * Math.sin(Math.toRadians(angle));

    if (frame < 12){
        frame++;
    }
    else frame = 0;
}

public void turn(double angle){    
    this.angle += angle;
}

public int getX() {
    return (int) x;
}

public int getY(){
    return (int) y;
}

public int getGunX() {
    return gunX;
}

public int getGunY(){
    return gunY;
}

public int getHeight(){
    return height;
}

public int getWidth(){
    return width;
}

public void setNB(int x, int y, double angle)//sets position and movement of bullet
{
    if (nb.size() > 10)
    {
        nb.set(0, null);
        nb.remove(nb.get(0));//removes the bullets from the game when tried to exceed 3
    }
    if (nb.size() < 10)//only 3 shots allowed at a time
    {
        nb.add(new Bullet(x, y, angle));//adds bullets to list when a new one is shot
    }
}

public ArrayList<Bullet> getNB()//sets position and movement of bullet
{
    return nb;
}

public void removeNB(int i)//removes bullet from game when it hits an asteroid
{
    nb.set(i, null);
    nb.remove(nb.get(i));
}

public int getBulletX(int i)//gets bullet X coord
{
    return nb.get(i).getX();
}

public int getBulletY(int i)//gets bullet Y coord
{
    return nb.get(i).getY();
}

public int getBulletWidth(int i)//gets bullet width
{
    return nb.get(i).getWidth();
}

public int getBulletHeight(int i)//gets bullet height
{
    return nb.get(i).getHeight();
}

public int getBulletAngle(int i)//gets bullet angle
{
    return nb.get(i).getAngle();
}

public double getAngle() {
    return angle;
}

public int amountOfBullets() //checks amount of bullets in game
{
    return nb.size();
}
}

项目符号：

public class Bullet
{  
//width = 6px, height = 8px
private BufferedImage bullet = null;
private BufferedImage img2 = null;
private double x, y;
private double angle;
//Creates an instance of timer since each bullet is supposed to only last 1.5 seconds
private Stopwatch timer = new Stopwatch();

public Bullet(int x, int y, double angle)
{   
    //Get the image of the normal bullet
    try { 
        bullet = ImageIO.read(getClass().getResource("/Bullet.png"));
    } catch (IOException e) { 
        System.err.println("Bullet.png could not be found");
    }
    //Sets the position and direction of the bullet relative to the spacecraft when it is created
    timer.start();
    this.x=x;
    this.y=y;
    this.angle=angle+90;
}

public void paint(Graphics2D g2d)
{
    //Since the bullet sprite is not always oriented in the direction of the shot, orient it properly
    angle-=90;

    double rotationRequired = Math.toRadians(angle);
    double locationX = bullet.getWidth() / 2;
    double locationY = bullet.getHeight() / 2;
    AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
    AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);

    // Drawing the rotated image at the required drawing locations
    int x = (int) this.x;
    int y = (int) this.y;
    //g.drawImage(img2, x - 150, y - 150, null);
    g2d.drawImage(op.filter(bullet, null), x, y, null);
    //Change the angle back to the original for the bullet to travel in the correct direction
    angle+=90;

}

public void move()
{
    //Move the projectile in the direction it is facing
    x+=-5* Math.cos(Math.toRadians(angle));
    y+=-5* Math.sin(Math.toRadians(angle));
}


//Returns how long the bullet has been in existence
public long getTime()
{
    return timer.getElapsedTime();
}

public int getX()//returns the x position of the bullet for collision detection
{
    return (int)x;
}

public int getY()//returns the y position of the bullet for collision detection
{
    return (int)y;
}

public int getWidth()//returns the width of the sprite for collision detection
{
    return bullet.getWidth();
}

public int getHeight()//returns the height of the sprite for collision detection
{
    return bullet.getHeight();
}

public int getAngle()//returns the angle of the bullet
{
    return (int)angle;
}
}

Answer 1

好的，这是您新的绘画移动和转动方法 - 您还需要变换枪尖：

public void paint(Graphics g2d){
    // Drawing the rotated image at the required drawing locations
    if(op!=null) g2d.drawImage(op.filter(currentImg, null), (int)x, (int)y, null);
    else g2d.drawImage(currentImg, (int)x, (int)y, null);
    g2d.setColor(Color.blue);
    g2d.fillOval(gunX, gunY, 10, 10);
}


public void move(double xM, double yM){
    x += xM * Math.cos(Math.toRadians(angle));
    y += yM * Math.sin(Math.toRadians(angle));

    gunY += yM * Math.sin(Math.toRadians(angle));
    gunX += xM * Math.cos(Math.toRadians(angle));

    repaint();
}


public void turn(double angle){    
    this.angle += angle;
    double rotationRequired = Math.toRadians (this.angle);
    double locationX = currentImg.getWidth() / 2;
    double locationY = currentImg.getHeight() / 2;
    AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
    op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);
    int gx= currentImg.getWidth() - 15;
    int gy=0;
    Point pt1=new Point(gx, gy), pt2=new Point();
    tx.transform(pt1, pt2);
    gunX=(int)x+pt2.x; gunY=(int)y+pt2.y;
    repaint();
}

你需要：

一个全局变量

AffineTransformOp op;

在播放器中。

我的子弹出现在错误的地方

My bullets spawn in the wrong place

java

affinetransform

game-physics

projectile