java - 我的碰撞是 buggy ，有时会剧烈振动或出界

Question

我正在使用 Beginning Android Games 中的游戏引擎并从头开始制作突破游戏。我的 Racket /球/积木可以正常工作，但现在我正在解决错误。随机地，我的乒乓球会撞到任何墙壁，它会粘在上面并左右振动，然后飞出屏幕。另一个例子是，有时乒乓球击打 Racket 的方式不是弹开它，而是穿过它，然后在穿过它后继续改变方向，我觉得它不遵守我的界限。我在 nexus 7 上测试这里是 pong 类

public class Pong {
    public float x, y;
    public int speedX, speedY;
    public static final int LEFT = 0;
    public static final int RIGHT = 0;
    public static final int WIDTH = 32;
    public static final int HEIGHT = 32;
    public static final int DIAMETER = 15;
    public int direction;
    public boolean inBounds;

    public Pong(int x, int y) {
        this.x = x;
        this.y = y;
        speedX = 500;
        speedY = 500;
        inBounds = true;
    }

    public void stop() {
        speedX = 0;
        speedY = 0;
    }

    public void update(float deltaTime) {
        if (inBounds) {
            x += speedX * deltaTime;
            y += speedY * deltaTime;
            if (x + WIDTH >= 800) {
                speedX *= -1;
            }
            if (x <= 0) {
                speedX *= -1;
            }
            if (y >= 1280) {
                // inBounds = false;
                speedY *= -1;
            }
            if (y <= 0) {
                speedY *= -1;
            }
        }

    }

    public void reverse() {
        speedY *= -1;
    }

}

我的划桨课

public class Paddle {
    public static final int LEFT = 0;
    public static final int RIGHT = 1;
    public static final int NEUTRAL = 2;
    public static final int WIDTH = 192;
    public static final int HEIGHT = 32;
    public float x;
    public int y;
    public int speed;
    public int direction;

    public Paddle(int x, int y) {
        this.x = x;
        this.y = y;

    }

    public void turnLeft() {
        speed = 500;
        direction = LEFT;
    }

    public void turnRight() {
        speed = 500;
        direction = RIGHT;
    }

    public void stop() {
        speed = 0;
    }

    public void update(float deltaTime) {

        if (direction == LEFT && x > 0) {
            x -= speed * deltaTime;
        } else if (direction == RIGHT && x + WIDTH < 800) {
            x += speed * deltaTime;
        } else if (direction == NEUTRAL) {
            stop();
        }

    }
}

我做的碰撞检测可能是错误的

private boolean paddleCollision(Paddle paddle, Pong pong) {
        if (pong.x <= paddle.x + Paddle.WIDTH) {
            if (pong.x >= paddle.x) {
                if (pong.y + Pong.HEIGHT >= paddle.y) {
                    return true;
                }
            }
        }
        return false;

    }

    private boolean tileCollision(Tile tile, Pong pong) {
        if (tile == null) {
            return false;
        }
        if (pong.x <= tile.x + Tile.WIDTH) {
            if (pong.x >= tile.x) {
                if (pong.y <= tile.y + Tile.HEIGHT) {
                    if (pong.y + Pong.HEIGHT >= tile.y) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

Answer 1

我不确定这是解决方案，但是:我不太喜欢 Paddle::update() Pong::update() 方法，因为 if (x > 0 ... x < 800)你要确保 initial 位置有效，然后将最终位置设置为可能在屏幕之外的位置......我会选择类似的东西:

public class Paddle {
    public void stop() {
        speed = 0;
        direction = NEUTRAL;        
    }

    public void update(float deltaTime) {
        // here, x is valid
        x += (direction == LEFT?-1:+1) * speed * deltaTime;

        if (x < 0) {
            x = 0;
            stop();
        }
        else if (x > 800) {
            x = 800;
            stop();
        }

        // here, x is valid
    }
}

public class Pong {
    public void update(float deltaTime) {
        if (inBounds) {
            x += speedX * deltaTime;
            y += speedY * deltaTime;
            if (x + WIDTH >= 800) {
                speedX *= -1;
                x = 800-WIDTH-1;
            }
            if (x <= 0) {
                speedX *= -1;
                x = 1;
            }
            if (y >= 1280) {
                speedY *= -1;
                y = 1279;
            }
            if (y <= 0) {
                speedY *= -1;
                y = 1;
            }

            // here, Pong is in screen
        }

    }
}