using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class CameraShake : MonoBehaviour {

    public void Shake(float duration, float magnitude){
        StartCoroutine(TheShake(duration, magnitude));
    }

    private IEnumerator TheShake(float duration, float magnitude){
        Vector3 pos = transform.localPosition;

        float elapsed = 0f; // 経過時間

        while(elapsed < duration){
            var x = pos.x + Random.Range(-1f, 1f) * magnitude;
            var y = pos.y + Random.Range(-1f, 1f) * magnitude;

            transform.localPosition = new Vector3(x, y, pos.z);
            elapsed += Time.deltaTime;

            yield return null;
        }

        transform.localPosition = pos;
    }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class PlayerHealth : MonoBehaviour {

    public int playerHP;
    public AudioClip damageSound;
    private Image damageScreenImage;
    private Color color;

    // ★視界を揺らす
    private CameraShake shake;

    void Start(){
        damageScreenImage = GameObject.Find("DamageScreen").GetComponent<Image>();
        color = damageScreenImage.color;
        color.a = 0.0f;
        damageScreenImage.color = color;

        // ★視界を揺らす
        shake = GameObject.Find("FPSCamera").GetComponent<CameraShake>();
    }

    void OnCollisionEnter(Collision other){
        if(other.gameObject.tag == "EnemyBullet"){
            playerHP -= 1;
            Destroy(other.gameObject);
            AudioSource.PlayClipAtPoint(damageSound, Camera.main.transform.position);
            color.a += 0.1f;
            damageScreenImage.color = color;

            // ★視界を揺らす
            shake.Shake(0.2f, 0.1f);
        }
    }

    public void AddHP(int amount){
        playerHP += amount;

        if(playerHP > 10){
            playerHP = 10;
        }

        float amountF = (float)amount;

        color.a -= (amountF / 10);

        if(color.a < 0){
            color.a = 0;
        }

        damageScreenImage.color = color;
    }
}