[Photo version] Separation of RGB and Alpha channels of images in the Unity Project,

[Photo version] Separation of RGB and Alpha channels of images in the Unity Project,

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

"There are two obvious problems in this article:
1. Processing the Alpha Texture is a pixel-per-pixel processing, using the Texture. SetPixel () function. We recommend that you use the Texture. SetPixels () function for batch processing. We recommend that you use the Texture. SetPixels () function for batch processing ."

Improvement:

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     }