【Archive】Make Your First Game

角色控制，包括移动与多段跳

朝向

float forward = Input.GetAxisRaw("Horizontal");// 返回-1,0,1
if (forward != 0) {
 transform.localScale = new Vector3(forward, 1, 1);
}

移动

public float speed;
private Rigidbody2D body;
void Start(){
 body = GetComponent<Rigidbody2D>();
}
void FixedUpDate(){
 float horizontalMove = Input.GetAxis("Horizontal");
 body.velocity =
        new Vector2(horizontalMove * speed * Time.fixedDeltaTime, body.velocity.y);
 // Input.GetAxis()返回-1f至1f的浮点，这么做会使角色移动产生“脚滑”的现象
}

跳跃

以跳跃作为核心玩法。

public float jumpForce;
public int finalJumpCount;// 用于重置jumpCount
public Transform footPoint;// 用于检测脚是否与地面接触
public LayerMask ground;// 代表地面Layer

private int jumpCount;// 代表玩家当前可跳跃的次数
private bool jumpPressed = false, isJumped = false;
private float time = -1f;// 用于确保jumpPressed随时处于正确状态的计时器
void Update() {
    // 在Update中确保能敏感地接收到起跳请求，再去FixedUpDate中进行Rigidbody相关的运算
    if (Input.GetButtonDown("Jump") && jumpCount > 0) {
        jumpPressed = true;
        time = Time.time + 0.05f;
    }
    if (time >= 0 && time < Time.time) {
        // 经过一个短暂的计时后重置jumpPressed
        jumpPressed = false;
        time = -1f;
    }
}
void FixedUpdate(){
    if (Physics2D.OverlapCircle(footPoint.position, 0.1f, ground)) {
        // 落地时重置跳跃相关的参数，而且要避免刚起跳时OverlapCircle检测到地面
        jumpCount = finalJumpCount;
        isJumped = false;
    }
    if (jumpPressed) {
        // 跳跃
        if (Physics2D.OverlapCircle(footPoint.position, 0.3f, ground)) {
            // 地面起跳
            body.velocity = new Vector2(body.velocity.x, jumpForce);
            jumpCount--;
            jumpPressed = false;
            isJumped = true;// 代表经过跳跃离开地面
        }
        else if (isJumped) {
            // 空中起跳
            body.velocity = new Vector2(body.velocity.x, jumpForce);
            jumpCount--;
            jumpPressed = false;
        }
        // 剩余情况为不经跳跃离开地面且没有消灭敌人/吃到樱桃时请求跳跃，不予起跳
    }
}

玩家与收集物的交互，与敌人的交互。

收集品、简单的UI

using UnityEngine.UI;

public Text diamondCount;
private int diamond = 0;

private void OnTriggerEnter2D(Collider2D collision) {
    if (collision.CompareTag("Cherry")) {
        Destroy(collision.gameObject);
        jumpCount++;
        isJumped = true;
        // 无论怎样离开地面，吃到樱桃后解锁跳跃条件
    }
    if (collision.CompareTag("Diamond")) {;
        Destroy(collision.gameObject);
        diamond++;
        diamondCount.text = diamond.ToString();
    }
}

敌人

父类

首先创建所有敌人类的父类 Enemy，其中播放死亡动画和摧毁对象的方法对所有敌人来说都是通用的。

public class Enemy : MonoBehaviour
{
    protected Animator animator;
    protected Rigidbody2D rb;

    private int deathID;
    protected virtual void Start() {
        animator = GetComponent<Animator>();
        rb = GetComponent<Rigidbody2D>();
        deathID = Animator.StringToHash("Death");
    }
    public void Death() {
        GetComponent<Collider2D>().enabled = false;
        rb.constraints = RigidbodyConstraints2D.FreezeAll;
        // 沿所有轴冻结旋转和移动，保证Enemy不至于一边被玩家一脚踹飞一边播放死亡动画
        animator.SetTrigger(deathID);
    }

    // 在Death动画的结尾调用
    public void Disappear() {
        Destroy(gameObject);
    }
}

Frog类

Frog 需要在一定范围内以跳跃的方式移动，这个坐标由他的两个子物体 leftPoint 和 rightPoint 提供。使用动画事件方便地使函数在正确的时机被调用。

public class EnemyFrog : Enemy
{
    public Transform leftPoint, rightPoint;
    public float speed;
    public float jumpForce;
    public LayerMask ground;
    public bool forwardLeft;

    private Rigidbody2D body;
    private Collider2D collisionBox;
    private float leftX, rightX;
    private int jumpingID, fallingID;
    protected override void Start() {
        base.Start();
        body = GetComponent<Rigidbody2D>();
        collisionBox = GetComponent<Collider2D>();
        leftX = leftPoint.position.x;
        rightX = rightPoint.position.x;
        Destroy(leftPoint.gameObject);
        Destroy(rightPoint.gameObject);
        // 获取移动范围坐标后即可摧毁标志对象
        jumpingID = Animator.StringToHash("Jumping");
        fallingID = Animator.StringToHash("Falling");
    }
    void Update() {
        if (animator.GetBool(jumpingID) && body.velocity.y <= 0) {
            animator.SetBool(jumpingID, false);
            animator.SetBool(fallingID, true);
        }
        if (animator.GetBool(fallingID) && collisionBox.IsTouchingLayers(ground)) {
            animator.SetBool(fallingID, false);
            body.velocity = new Vector2(0, 0);
        }
    }
    void movement() {// 在Idel动画的结尾调用
        if (forwardLeft) {// 朝左
            if (transform.position.x <= leftX) {// 需要转身
                forwardLeft = false;
                transform.localScale = new Vector3(-1, 1, 1);
            }
            body.velocity = new Vector2(-transform.localScale.x * speed, jumpForce);
            animator.SetBool(jumpingID, true);
        }
        else {// 朝右
            if (transform.position.x >= rightX) {// 需要转身
                forwardLeft = true;
                transform.localScale = new Vector3(1, 1, 1);
            }
            body.velocity = new Vector2(-transform.localScale.x * speed, jumpForce);
            animator.SetBool(jumpingID, true);
        }
    }
}

PlayerController类

private void OnCollisionEnter2D(Collision2D collision) {
    if (collision.gameObject.CompareTag("Enemy")) {// 触敌
        if (animator.GetBool(fallingID) &&
            transform.position.y - collision.transform.position.y > 0.35f) {

            // 保证触敌时两者处于一个相对垂直的位置
            Enemy enemy = collision.gameObject.GetComponent<Enemy>();
            enemy.Death();
            body.velocity = new Vector2(body.velocity.x, jumpForce);
            jumpCount = finalJumpCount;
            isJumped = true;
            // 无论怎样离开地面，消灭敌人后解锁跳跃条件
        }
        else {// 受伤
            isHurt = true;// 用于切换动画以及屏蔽受伤状态下移动相关的输入
            if (transform.position.x <= collision.transform.position.x) {// 右侧触敌
                body.velocity = new Vector2(-10f, body.velocity.y + jumpForce * 0.7f);
            }
            else {// 左侧接敌
                body.velocity = new Vector2(10f, body.velocity.y + jumpForce * 0.7f);
            }
        }
    }
}

对话框、运动透视、菜单中调节音量。

对话框提示

对话框的渐入渐出和移动由录制动画实现，通用的 Dialog 类挂载在一个 Trigger 上，负责动画的切换。

public class Dialog : MonoBehaviour
{
    public GameObject dialog;

    private Animator animator;
    private int enterID,exitID;
    private void Start() {
        animator = dialog.GetComponent<Animator>();
        enterID = Animator.StringToHash("Enter");
        exitID = Animator.StringToHash("Exit");
    }
    private void OnTriggerStay2D(Collider2D collision) {
        if (collision.CompareTag("Player") && !dialog.activeSelf) {
            dialog.SetActive(true);
            animator.SetBool(enterID, true);
            animator.SetBool(exitID, false);
        }
    }
    private void OnTriggerExit2D(Collider2D collision) {
        if (collision.CompareTag("Player")) {
            animator.SetBool(enterID, false);
            animator.SetBool(exitID, true);
            Invoke("setActiceFalse", 0.1f);//等待退出动画结束
        }
    }
    private void setActiceFalse() {
        dialog.SetActive(false);
    }
}

运动透视

将这个脚本挂载在某一层背景上。

public class Parallax : MonoBehaviour
{
    public new Transform camera;
    public float moveRate;
    public bool lockY;

    private float bgStartX, bgStartY;
    private float cmStartX, cmStartY;
    void Start(){
        bgStartX = transform.position.x;
        bgStartY = transform.position.y;

        cmStartX = camera.position.x;
        cmStartY = camera.position.y;
    }
    void Update(){
        float difX = camera.position.x - cmStartX;
        float difY = camera.position.y - cmStartY;

        if (lockY) {
            transform.position = new Vector2(bgStartX + difX * moveRate,
                transform.position.y);
        }
        else {
            transform.position =
                new Vector2(bgStartX + difX, bgStartY + difY) * moveRate;
        }
    }
}

音量调节

将所有 Source 输出到一个 Mixer 内，若想更新 Mixer 的属性（比如音量），需先将音频组检视面板中的属性暴露出来再 Set。再将该函数交由一 SliderUI 调用，动态地传入值即可。

public void SetAudioVolume(float volume) {
    audioMixer.SetFloat("MainVolume", volume);
}

相关链接

M_Studio
Input
Rigidbody2D
Physics2D
RigidbodyConstraints2D
timeScale