【改进版】Unity工程里图片的RGB和Alpha通道的分离

http://blog.csdn.net/u010153703/article/details/39477887

“这篇文章里有两个明显的问题：
1. 处理Alpha贴图时是一个像素一个像素地处理，用Texture.SetPixel()函数。推荐批量处理，用Texture.SetPixels()函数。推荐批量处理，用Texture.SetPixels()函数。”

改进之：

using UnityEngine;  using System.Collections;  using System.Collections.Generic;  using UnityEditor;  using System.IO;  using System.Reflection;    public class MaterialTextureForETC1{    private static string defaultWhiteTexPath_relative = "Assets/Default_Alpha.png";    private static Texture2D defaultWhiteTex = null;      [MenuItem("EffortForETC1/Depart RGB and Alpha Channel")]    static void SeperateAllTexturesRGBandAlphaChannel()    {        Debug.Log("Start Departing.");        if (!GetDefaultWhiteTexture())        {            return;        }              string[] paths = Directory.GetFiles(Application.dataPath, "*.*", SearchOption.AllDirectories);        foreach (string path in paths)        {            if (!string.IsNullOrEmpty(path) && IsTextureFile(path) && !IsTextureConverted(path))   //full name              {                SeperateRGBAandlphaChannel(path);            }        }        AssetDatabase.Refresh();    //Refresh to ensure new generated RBA and Alpha textures shown in Unity as well as the meta file        Debug.Log("Finish Departing.");    }    #region process texture    static void SeperateRGBAandlphaChannel(string _texPath)    {        string assetRelativePath = GetRelativeAssetPath(_texPath);        SetTextureReadableEx(assetRelativePath);    //set readable flag and set textureFormat TrueColor        Texture2D sourcetex = Resources.LoadAssetAtPath(assetRelativePath, typeof(Texture2D)) as Texture2D;  //not just the textures under Resources file          if (!sourcetex)        {            Debug.LogError("Load Texture Failed : " + assetRelativePath);            return;        }        TextureImporter ti = null;        try        {            ti = (TextureImporter)TextureImporter.GetAtPath(assetRelativePath);        }        catch        {            Debug.LogError("Load Texture failed: " + assetRelativePath);            return;        }        if (ti == null)        {            return;        }          bool bGenerateMipMap = ti.mipmapEnabled;    //same with the texture import setting              Texture2D rgbTex = new Texture2D(sourcetex.width, sourcetex.height, TextureFormat.RGB24, bGenerateMipMap);        rgbTex.SetPixels(sourcetex.GetPixels());             Texture2D mipMapTex = new Texture2D(sourcetex.width, sourcetex.height, TextureFormat.RGBA32, true);  //Alpha Channel needed here        mipMapTex.SetPixels(sourcetex.GetPixels());        mipMapTex.Apply();        Color[] colors2rdLevel = mipMapTex.GetPixels(1);   //Second level of Mipmap        Color[] colorsAlpha = new Color[colors2rdLevel.Length];        if (colors2rdLevel.Length != (mipMapTex.width+1) / 2 * (mipMapTex.height+1) / 2)        {            Debug.LogError("Size Error.");            return;        }        bool bAlphaExist = false;        for (int i = 0; i < colors2rdLevel.Length; ++i)        {            colorsAlpha[i].r = colors2rdLevel[i].a;            colorsAlpha[i].g = colors2rdLevel[i].a;            colorsAlpha[i].b = colors2rdLevel[i].a;            if (!Mathf.Approximately(colors2rdLevel[i].a, 1.0f))            {                bAlphaExist = true;            }        }        Texture2D alphaTex = null;        if (bAlphaExist)        {            alphaTex = new Texture2D((sourcetex.width+1) / 2, (sourcetex.height+1) / 2, TextureFormat.RGB24, bGenerateMipMap);        }        else        {            alphaTex = new Texture2D(defaultWhiteTex.width, defaultWhiteTex.height, TextureFormat.RGB24, false);        }        alphaTex.SetPixels(colorsAlpha);        rgbTex.Apply();        alphaTex.Apply();        byte[] bytes = rgbTex.EncodeToPNG();        File.WriteAllBytes(assetRelativePath, bytes);        byte[] alphabytes = alphaTex.EncodeToPNG();        string alphaTexRelativePath = GetAlphaTexPath(_texPath);        File.WriteAllBytes(alphaTexRelativePath, alphabytes);        ReImportAsset(assetRelativePath, rgbTex.width, rgbTex.height);        ReImportAsset(alphaTexRelativePath, alphaTex.width, alphaTex.height);        Debug.Log("Succeed Departing : " + assetRelativePath);    }    static void ReImportAsset(string path, int width, int height)    {        try        {            AssetDatabase.ImportAsset(path);        }        catch        {            Debug.LogError("Import Texture failed: " + path);            return;        }        TextureImporter importer = null;        try        {            importer = (TextureImporter)TextureImporter.GetAtPath(path);        }        catch        {            Debug.LogError("Load Texture failed: " + path);            return;        }        if (importer == null)        {            return;        }        importer.maxTextureSize = Mathf.Max(width, height);        importer.anisoLevel = 0;        importer.isReadable = false;  //increase memory cost if readable is true        importer.textureFormat = TextureImporterFormat.AutomaticCompressed;        importer.textureType = TextureImporterType.Image;        if (path.Contains("/UI/"))        {            importer.textureType = TextureImporterType.GUI;        }        AssetDatabase.ImportAsset(path);    }    static void SetTextureReadableEx(string _relativeAssetPath)    //set readable flag and set textureFormat TrueColor    {        TextureImporter ti = null;        try        {            ti = (TextureImporter)TextureImporter.GetAtPath(_relativeAssetPath);        }        catch        {            Debug.LogError("Load Texture failed: " + _relativeAssetPath);            return;        }        if (ti == null)        {            return;        }               ti.isReadable = true;        ti.textureFormat = TextureImporterFormat.AutomaticTruecolor;      //this is essential for departing Textures for ETC1. No compression format for following operation.        AssetDatabase.ImportAsset(_relativeAssetPath);    }    static bool GetDefaultWhiteTexture()    {        defaultWhiteTex = Resources.LoadAssetAtPath(defaultWhiteTexPath_relative, typeof(Texture2D)) as Texture2D;  //not just the textures under Resources file          if (!defaultWhiteTex)        {            Debug.LogError("Load Texture Failed : " + defaultWhiteTexPath_relative);            return false;        }        return true;    }    #endregion       #region string or path helper        static bool IsTextureFile(string _path)      {          string path = _path.ToLower();          return path.EndsWith(".psd") || path.EndsWith(".tga") || path.EndsWith(".png") || path.EndsWith(".jpg") || path.EndsWith(".bmp") || path.EndsWith(".tif") || path.EndsWith(".gif");      }    static bool IsTextureConverted(string _path)    {        return _path.Contains("_RGB.") || _path.Contains("_Alpha.");    }      static string GetRGBTexPath(string _texPath)      {          return GetTexPath(_texPath, "_RGB.");      }        static string GetAlphaTexPath(string _texPath)      {          return GetTexPath(_texPath, "_Alpha.");      }        static string GetTexPath(string _texPath, string _texRole)      {        string dir = System.IO.Path.GetDirectoryName(_texPath);        string filename = System.IO.Path.GetFileNameWithoutExtension(_texPath);        string result = dir + "/" + filename + _texRole + "png";        return result;      }        static string GetRelativeAssetPath(string _fullPath)      {          _fullPath = GetRightFormatPath(_fullPath);          int idx = _fullPath.IndexOf("Assets");          string assetRelativePath = _fullPath.Substring(idx);          return assetRelativePath;      }        static string GetRightFormatPath(string _path)      {          return _path.Replace("\\", "/");      }       #endregion     }