Convert sprite mapping to custom font settings in Unity 3D

ConvertSpriteToFont

    [MenuItem(ItemNamePrefix + "Convert Font")]
    public static void ConvertFont()
    {
        var sb = new StringBuilder();
        var objs = AssetDatabase.LoadAllAssetsAtPath("Assets/Amstrad/AmstradFont.psd");
        var sprites = objs.OfType<Sprite>().OrderBy(s => CalcIndex(s.name)).ToArray();
        foreach (var sprite in sprites)
        {
            sb.AppendLine("name " + sprite.name);
            sb.AppendLine("rect " + sprite.rect);
        }
        Debug.Log(sb.ToString());

        var font = AssetDatabase.LoadAssetAtPath<Font>("Assets/Amstrad/Amstrad.fontsettings");
        Debug.Log(font);
        var ci = new CharacterInfo
        {
            minX = 0, minY = -8, maxX = 8, maxY = 0, uvBottomLeft = new Vector2(4, 4), uvTopRight = new Vector2(12, 12), advance = 8
        };
        var characterInfo = new CharacterInfo[256];
        for (int i = 0; i < 256; i++)
        {
            var sprite = sprites[i];
            var r = sprite.rect;
            ci.index = i;
            ci.uvBottomLeft = new Vector2(r.xMin/ 256, r.yMin / 256);
            ci.uvTopRight = new Vector2(r.xMax / 256, r.yMax / 256);
            characterInfo[i] = ci;
        }
        font.characterInfo = characterInfo;
        EditorUtility.SetDirty(font);
        AssetDatabase.SaveAssets();
    }

    private static int CalcIndex(string name)
    {
        var i = name.IndexOf('_');
        try
        {
            return int.Parse(name.Substring(i+1));
        }
        catch (Exception ex)
        {
            Debug.LogError(ex.Message + " "+name+" "+i);
            throw;
        }
    }