判断资源贴图是否有alpha

/*

  modfly selected textures`s maxSize and ImportFormat

  bool hasAlpha = true;

  if(hasAlpha)then(texture.size/2 and trueColor)else(16bit)

2014.05.27

*/
using UnityEngine;

using System.Collections;

using UnityEditor;

public class modflyTextures : ScriptableObject{
[MenuItem ("Custom/modflyTextures")]

    static void processTexture_Auto() {

        processTexture();

    }
static void processTexture() {
Object[] textures = GetSelectedTextures();

        Selection.objects = new Object[0];

        foreach (Texture2D tex in textures)  {

            string path = AssetDatabase.GetAssetPath(tex);

            TextureImporter importerTexture = AssetImporter.GetAtPath(path) as TextureImporter;
if(importerTexture.DoesSourceTextureHaveAlpha() ==  true){

                if(tex.width >= tex.height )

                    importerTexture.maxTextureSize = tex.width/2;

                else importerTexture.maxTextureSize = tex.height/2;
importerTexture.textureFormat = TextureImporterFormat.AutomaticTruecolor;

            }else{

                if(tex.width >= tex.height )

                    importerTexture.maxTextureSize = tex.width;

                else importerTexture.maxTextureSize = tex.height;
importerTexture.textureFormat = TextureImporterFormat.AutomaticCompressed;

            }

            AssetDatabase.ImportAsset(path);

        }

    }
static Object[] GetSelectedTextures()

    {

        return Selection.GetFiltered(typeof(Texture2D), SelectionMode.DeepAssets);

    }

}

判断资源贴图是否有alpha