资源工作流之自动设置图片格式

此工具的作用：
1.可以帮助策划or美术导入图片自动设置为Sprite格式
2.并且设置默认的压缩方式

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;

public class SpriteImportEditor : AssetPostprocessor
{
    const string SYMBOL_ALTAS = "Altas";

    const string SYMBOL_ANDROID = "Android";
    const string SYMBOL_IPHONE = "iPhone";

    const string FORDER_RGB32 = "rgb32";
    const string FORDER_SHOP = "shop";
    const string FORDER_LOADING = "loading";
    const string FORDER_ZDW = "zdw";

    const string NAME_DOOR = "_dm_0";

    const string DIR_UI = "Assets/GameRes/UI/Sprites/";
    const string DIR_MAP = "Assets/GameRes/Maps/Sprites/";


    private void OnPreprocessTexture()
    {
        TextureImporter importer = (TextureImporter)assetImporter;
        string assetPath = importer.assetPath;
        bool isInAltas = assetPath.Contains(SYMBOL_ALTAS);
        if (!isInAltas) //不是图集的，先不管，可能需要定制参数
        {
            return;
        }
        Debug.LogFormat("自动帮您导入图片 纠正格式 : {0}", assetPath);
        bool bInUIDir = assetPath.StartsWith(DIR_UI);
        bool bInMap = assetPath.StartsWith(DIR_MAP);
        if (bInUIDir || bInMap)
        {
            OnPreprocess_Internal(importer);
        }
    }

    private void OnPreprocess_Internal(TextureImporter importer)
    {
        NormalSet(importer);
        GetAlphaSet(importer, out int maxSize, out TextureImporterFormat format);
        AndroidSet(importer, format, maxSize);
        iPhoneSet(importer, format, maxSize);
    }

    // ================================================================================================ //

    void NormalSet(TextureImporter importer)
    {
        importer.isReadable = false;
        importer.textureType = TextureImporterType.Sprite;
    }

    bool NeedSetRGBA32_Size1024()
    {
        bool bRGB32 = assetPath.Contains(FORDER_RGB32);
        bool bInShop = assetPath.Contains(FORDER_SHOP);//商城的NB一点
        bool bDoor = assetPath.Contains(NAME_DOOR);//美术说：大门需要高清
        return bRGB32 || bInShop || bDoor;
    }
    bool NeedSetSize128()
    {
        bool bInZdw = assetPath.Contains(FORDER_ZDW);
        return bInZdw;
    }
    bool NeedSetSize1024()
    {
        bool bInLoading = assetPath.Contains(FORDER_LOADING);
        return bInLoading;
    }

    void GetAlphaSet(TextureImporter importer, out int maxSize, out TextureImporterFormat format)
    {
        if (importer.DoesSourceTextureHaveAlpha())
        {
            if (NeedSetRGBA32_Size1024())
            {
                format = TextureImporterFormat.RGBA32;
                maxSize = 1024;
            }
            else
            {
                format = TextureImporterFormat.ETC2_RGBA8;
                maxSize = 512;
                if (NeedSetSize128())
                {
                    maxSize = 128;
                }
                if (NeedSetSize1024())
                {
                    maxSize = 1024;
                }
            }
        }
        else
        {
            format = TextureImporterFormat.ETC2_RGB4;
            maxSize = 512;
        }
    }

    void AndroidSet(TextureImporter importer, TextureImporterFormat format, int maxSize = 512)
    {
        importer.GetPlatformTextureSettings(SYMBOL_ANDROID, out _, out _);
        TextureImporterPlatformSettings settings = new TextureImporterPlatformSettings
        {
            name = SYMBOL_ANDROID,
            format = format,
            maxTextureSize = maxSize,
            crunchedCompression = true,
            overridden = true
        };
        importer.SetPlatformTextureSettings(settings);
    }

    void iPhoneSet(TextureImporter importer, TextureImporterFormat format, int maxSize = 512)
    {
        importer.GetPlatformTextureSettings(SYMBOL_ANDROID, out _, out _);
        TextureImporterPlatformSettings settings = new TextureImporterPlatformSettings
        {
            name = SYMBOL_IPHONE,
            format = format,
            maxTextureSize = maxSize,
            crunchedCompression = true,
            overridden = true
        };
        importer.SetPlatformTextureSettings(settings);
    }
}