using UnityEngine;
using System.Collections;
using System.Collections.Generic;
/// <summary>
/// 腳本掛載到墻上
/// </summary>

public class ImageFusion : MonoBehaviour {


    public Texture2D bulletTexture;     // 【圖片】彈痕 
    private Texture2D wallTexture;      // 【圖片】墻
    private Texture2D NewWallTexture;   // 【圖片】墻的備份


    private float wall_height;      // 【獲取墻和彈痕圖片的寬高信息】 
    private float wall_width;

    private float bullet_height;
    private float bullet_width;

    RaycastHit hit;                 // 獲取子彈打擊點

    private Queue<Vector2> uiQueues;    // 存儲像素點信息

    // Use this for initialization
    void Start () {
        uiQueues = new Queue<Vector2> ();

        wallTexture = GetComponent<MeshRenderer> ().material.mainTexture as Texture2D;
        // 【備份墻的圖片】
        NewWallTexture = Instantiate (wallTexture);

        GetComponent<MeshRenderer> ().material.mainTexture = NewWallTexture;

        wall_height = wallTexture.height;
        wall_width = wallTexture.width;

        bullet_height = bulletTexture.height;
        bullet_width = bulletTexture.width;

        Debug.Log (wall_width);
        Debug.Log (bullet_width);
    }

    // Update is called once per frame
    void Update () {
        if (Input.GetMouseButtonDown(0)) {
            Ray ray = Camera.main.ScreenPointToRay (Input.mousePosition);
            if (Physics.Raycast(ray,out hit)) {
                if (hit.collider.name == "Plane") {
                    // 得到打擊點的圖片UV坐標
                    // UV坐標是當前圖片寬高的百分比【左下角(0,0)，右上角(1,1)】
                    Vector2 uv = hit.textureCoord;

                    uiQueues.Enqueue (uv);

                    for (int i = 0; i < bullet_width; i++) {
                        for (int j = 0; j < bullet_height; j++) {
                            // 先減去彈痕寬度的一半得到最左邊的坐標，依次向右遞增
                            float w = uv.x * wall_width - bullet_width / 2 + i;
                            // 同理，從下到上遞增
                            float h = uv.y * wall_height - bullet_height / 2 + j;


                            Color wallColor = NewWallTexture.GetPixel ((int)w, (int)h);
                            Color bulletColor = bulletTexture.GetPixel (i, j);
                            // 修改彈痕位置的像素為兩圖的融合顏色，若不相乘融合會使用彈痕原圖
                            NewWallTexture.SetPixel ((int)w, (int)h, wallColor * bulletColor);
                        }
                    }
                    // 應用圖片
                    NewWallTexture.Apply ();
                    Invoke ("ReturnWall", 3f);
                }
            }
        }
    }


    void ReturnWall()
    {
        // 還原以打擊點為原點的圖片像素點
        Vector2 uv = uiQueues.Dequeue ();

        for (int i = 0; i < bullet_width; i++) {
            for (int j = 0; j < bullet_height; j++) {
                float w = uv.x * wall_width - bullet_width / 2 + i;
                float h = uv.y * wall_height - bullet_height / 2 + j;

                // 使用原圖的像素進行還原
                Color wallColor = wallTexture.GetPixel ((int)w,(int)h);
                NewWallTexture.SetPixel ((int)w, (int)h, wallColor);
            }
        }
        NewWallTexture.Apply ();
    }










}