using UnityEngine;
using System.Collections;
using System.Collections.Generic;
/// <summary>
/// 脚本挂载到墙上
/// </summary>

public class ImageFusion : MonoBehaviour {


    public Texture2D bulletTexture;     // 【图片】弹痕 
    private Texture2D wallTexture;      // 【图片】墙
    private Texture2D NewWallTexture;   // 【图片】墙的备份


    private float wall_height;      // 【获取墙和弹痕图片的宽高信息】 
    private float wall_width;

    private float bullet_height;
    private float bullet_width;

    RaycastHit hit;                 // 获取子弹打击点

    private Queue<Vector2> uiQueues;    // 存储像素点信息

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

        wallTexture = GetComponent<MeshRenderer> ().material.mainTexture as Texture2D;
        // 【备份墙的图片】
        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") {
                    // 得到打击点的图片UV坐标
                    // UV坐标是当前图片宽高的百分比【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++) {
                            // 先减去弹痕宽度的一半得到最左边的坐标，依次向右递增
                            float w = uv.x * wall_width - bullet_width / 2 + i;
                            // 同理，从下到上递增
                            float h = uv.y * wall_height - bullet_height / 2 + j;


                            Color wallColor = NewWallTexture.GetPixel ((int)w, (int)h);
                            Color bulletColor = bulletTexture.GetPixel (i, j);
                            // 修改弹痕位置的像素为两图的融合颜色，若不相乘融合会使用弹痕原图
                            NewWallTexture.SetPixel ((int)w, (int)h, wallColor * bulletColor);
                        }
                    }
                    // 应用图片
                    NewWallTexture.Apply ();
                    Invoke ("ReturnWall", 3f);
                }
            }
        }
    }


    void ReturnWall()
    {
        // 还原以打击点为原点的图片像素点
        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;

                // 使用原图的像素进行还原
                Color wallColor = wallTexture.GetPixel ((int)w,(int)h);
                NewWallTexture.SetPixel ((int)w, (int)h, wallColor);
            }
        }
        NewWallTexture.Apply ();
    }










}