FontAssetCreatorWindow.cs

// Unity C# reference source
// Copyright (c) Unity Technologies. For terms of use, see
// https://unity3d.com/legal/licenses/Unity_Reference_Only_License

using System.Collections.Generic;
using System.Globalization;
using System.Threading;
using System.IO;
using System.Text.RegularExpressions;
using UnityEngine;
using UnityEngine.TextCore.Text;

using UnityEngine.TextCore.LowLevel;
using UnityEditor.TextCore.LowLevel;
using Object = UnityEngine.Object;
using TextAsset = UnityEngine.TextAsset;

using FaceInfo = UnityEngine.TextCore.FaceInfo;
using Glyph = UnityEngine.TextCore.Glyph;
using GlyphRect = UnityEngine.TextCore.GlyphRect;
using GlyphMetrics = UnityEngine.TextCore.GlyphMetrics;
using System;

#pragma warning disable CS0618 // Font feature tables and OTL feature tags; TextCoreShaderGUI, TextCoreShaderGUISDF, TextCoreShaderGUIBitmap, TextShaderUtilities are obsolete; handled natively by ATG

namespace UnityEditor.TextCore.Text
{
    public class FontAssetCreatorWindow : EditorWindow
    {
        [MenuItem("Window/Text/Font Asset Creator", false, 2025)]
        internal static void ShowFontAtlasCreatorWindow()
        {
            var window = GetWindow<FontAssetCreatorWindow>();
            window.titleContent = new GUIContent("Font Asset Creator");
            window.Focus();

            // Make sure TMP Essential Resources have been imported.
            window.CheckEssentialResources();
        }

        public static void ShowFontAtlasCreatorWindow(Font font)
        {
            var window = GetWindow<FontAssetCreatorWindow>();

            window.titleContent = new GUIContent("Font Asset Creator");
            window.Focus();

            window.ClearGeneratedData();
            window.m_LegacyFontAsset = null;
            window.m_SelectedFontAsset = null;

            // Override selected font asset
            window.m_SourceFont = font;

            // Make sure TMP Essential Resources have been imported.
            window.CheckEssentialResources();
        }

        public static void ShowFontAtlasCreatorWindow(FontAsset fontAsset)
        {
            var window = GetWindow<FontAssetCreatorWindow>();

            window.titleContent = new GUIContent("Font Asset Creator");
            window.Focus();

            // Clear any previously generated data
            window.ClearGeneratedData();
            window.m_LegacyFontAsset = null;

            // Load font asset creation settings if we have valid settings
            if (string.IsNullOrEmpty(fontAsset.fontAssetCreationEditorSettings.sourceFontFileGUID) == false)
            {
                window.LoadFontCreationSettings(fontAsset.fontAssetCreationEditorSettings);

                // Override settings to inject character list from font asset
                // window.m_CharacterSetSelectionMode = 6;
                // window.m_CharacterSequence = TextCoreEditorUtilities.GetUnicodeCharacterSequence(FontAsset.GetCharactersArray(fontAsset));


                window.m_ReferencedFontAsset = fontAsset;
                window.m_SavedFontAtlas = fontAsset.atlasTexture;
            }
            else
            {
                window.m_WarningMessage = "Font Asset [" + fontAsset.name + "] does not contain any previous \"Font Asset Creation Settings\". This usually means [" + fontAsset.name + "] was created before this new functionality was added.";
                window.m_SourceFont = null;
                window.m_LegacyFontAsset = fontAsset;
            }

            // Even if we don't have any saved generation settings, we still want to pre-select the source font file.
            window.m_SelectedFontAsset = fontAsset;

            // Make sure TMP Essential Resources have been imported.
            window.CheckEssentialResources();
        }

        [System.Serializable]
        class FontAssetCreationSettingsContainer
        {
            public List<FontAssetCreationEditorSettings> fontAssetCreationSettings;
        }

        FontAssetCreationSettingsContainer m_FontAssetCreationSettingsContainer;

        //static readonly string[] m_FontCreationPresets = new string[] { "Recent 1", "Recent 2", "Recent 3", "Recent 4" };
        int m_FontAssetCreationSettingsCurrentIndex = 0;

        const string k_FontAssetCreationSettingsContainerKey = "TextMeshPro.FontAssetCreator.RecentFontAssetCreationSettings.Container";
        const string k_FontAssetCreationSettingsCurrentIndexKey = "TextMeshPro.FontAssetCreator.RecentFontAssetCreationSettings.CurrentIndex";
        const float k_TwoColumnControlsWidth = 335f;

        // Diagnostics
        System.Diagnostics.Stopwatch m_StopWatch;
        double m_GlyphPackingGenerationTime;
        double m_GlyphRenderingGenerationTime;

        string[] m_FontSizingOptions = { "Auto Sizing", "Custom Size" };
        int m_PointSizeSamplingMode;
        string[] m_FontResolutionLabels = { "8", "16", "32", "64", "128", "256", "512", "1024", "2048", "4096", "8192" };
        int[] m_FontAtlasResolutions = { 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192 };
        string[] m_FontCharacterSets = { "ASCII", "Extended ASCII", "ASCII Lowercase", "ASCII Uppercase", "Numbers + Symbols", "Custom Range", "Unicode Range (Hex)", "Custom Characters", "Characters from File" };
        enum FontPackingModes { Fast = 0, Optimum = 4 };
        FontPackingModes m_PackingMode = FontPackingModes.Fast;

        int m_CharacterSetSelectionMode;

        string m_CharacterSequence = "";
        string m_OutputFeedback = "";
        string m_WarningMessage;
        int m_CharacterCount;
        Vector2 m_ScrollPosition;
        Vector2 m_OutputScrollPosition;

        bool m_IsRepaintNeeded;

        float m_AtlasGenerationProgress;
        string m_AtlasGenerationProgressLabel = string.Empty;
        bool m_IsGlyphPackingDone;
        bool m_IsGlyphRenderingDone;
        bool m_IsRenderingDone;
        bool m_IsProcessing;
        bool m_IsGenerationDisabled;
        bool m_IsGenerationCancelled;

        bool m_IsFontAtlasInvalid;
        Font m_SourceFont;
        int m_SourceFontFaceIndex;
        private string[] m_SourceFontFaces = Array.Empty<string>();
        FontAsset m_SelectedFontAsset;
        FontAsset m_LegacyFontAsset;
        FontAsset m_ReferencedFontAsset;

        TextAsset m_CharactersFromFile;
        int m_PointSize;
        float m_PaddingFieldValue = 10;
        int m_Padding;

        enum PaddingMode { Undefined = 0, Percentage = 1, Pixel = 2 };

        string[] k_PaddingOptionLabels = { "%", "px" };
        private PaddingMode m_PaddingMode = PaddingMode.Percentage;

        GlyphRenderMode m_GlyphRenderMode = GlyphRenderMode.SDFAA;
        int m_AtlasWidth = 512;
        int m_AtlasHeight = 512;
        byte[] m_AtlasTextureBuffer;
        Texture2D m_FontAtlasTexture;
        Texture2D m_GlyphRectPreviewTexture;
        Texture2D m_SavedFontAtlas;

        //
        List<Glyph> m_FontGlyphTable = new List<Glyph>();
        List<Character> m_FontCharacterTable = new List<Character>();

        Dictionary<uint, uint> m_CharacterLookupMap = new Dictionary<uint, uint>();
        Dictionary<uint, List<uint>> m_GlyphLookupMap = new Dictionary<uint, List<uint>>();

        List<Glyph> m_GlyphsToPack = new List<Glyph>();
        List<Glyph> m_GlyphsPacked = new List<Glyph>();
        List<GlyphRect> m_FreeGlyphRects = new List<GlyphRect>();
        List<GlyphRect> m_UsedGlyphRects = new List<GlyphRect>();
        List<Glyph> m_GlyphsToRender = new List<Glyph>();
        List<uint> m_AvailableGlyphsToAdd = new List<uint>();
        List<uint> m_MissingCharacters = new List<uint>();
        List<uint> m_ExcludedCharacters = new List<uint>();

        private FaceInfo m_FaceInfo;

        bool m_IncludeFontFeatures;


        public void OnEnable()
        {
            // Used for Diagnostics
            m_StopWatch = new System.Diagnostics.Stopwatch();

            // Set Editor window size.
            minSize = new Vector2(315, minSize.y);

            // Initialize & Get shader property IDs.
            TextShaderUtilities.GetShaderPropertyIDs();

            // Load last selected preset if we are not already in the process of regenerating an existing font asset (via the Context menu)
            if (EditorPrefs.HasKey(k_FontAssetCreationSettingsContainerKey))
            {
                if (m_FontAssetCreationSettingsContainer == null)
                    m_FontAssetCreationSettingsContainer = JsonUtility.FromJson<FontAssetCreationSettingsContainer>(EditorPrefs.GetString(k_FontAssetCreationSettingsContainerKey));

                if (m_FontAssetCreationSettingsContainer.fontAssetCreationSettings != null && m_FontAssetCreationSettingsContainer.fontAssetCreationSettings.Count > 0)
                {
                    // Load Font Asset Creation Settings preset.
                    if (EditorPrefs.HasKey(k_FontAssetCreationSettingsCurrentIndexKey))
                        m_FontAssetCreationSettingsCurrentIndex = EditorPrefs.GetInt(k_FontAssetCreationSettingsCurrentIndexKey);

                    LoadFontCreationSettings(m_FontAssetCreationSettingsContainer.fontAssetCreationSettings[m_FontAssetCreationSettingsCurrentIndex]);
                }
            }

            // Get potential font face and styles for the current font.
            m_SourceFontFaces = GetFontFaces();

            ClearGeneratedData();
        }

        public void OnDisable()
        {
            //Debug.Log("TextMeshPro Editor Window has been disabled.");

            // Destroy Engine only if it has been initialized already
            FontEngine.DestroyFontEngine();

            ClearGeneratedData();

            // Remove Glyph Report if one was created.
            if (File.Exists("Assets/TextMesh Pro/Glyph Report.txt"))
            {
                File.Delete("Assets/TextMesh Pro/Glyph Report.txt");
                File.Delete("Assets/TextMesh Pro/Glyph Report.txt.meta");

                AssetDatabase.Refresh();
            }

            // Save Font Asset Creation Settings Index
            SaveCreationSettingsToEditorPrefs(SaveFontCreationSettings());
            EditorPrefs.SetInt(k_FontAssetCreationSettingsCurrentIndexKey, m_FontAssetCreationSettingsCurrentIndex);

            // Unregister to event
            TextEventManager.RESOURCE_LOAD_EVENT.Remove(ON_RESOURCES_LOADED);

            Resources.UnloadUnusedAssets();
        }

        // Event received when TMP resources have been loaded.
        void ON_RESOURCES_LOADED()
        {
            TextEventManager.RESOURCE_LOAD_EVENT.Remove(ON_RESOURCES_LOADED);

            m_IsGenerationDisabled = false;
        }

        // Make sure TMP Essential Resources have been imported.
        void CheckEssentialResources()
        {
            // TODO: Update this
            // if (TMP_Settings.instance == null)
            // {
            //     if (m_IsGenerationDisabled == false)
            //         TMPro_EventManager.RESOURCE_LOAD_EVENT.Add(ON_RESOURCES_LOADED);
            //
            //     m_IsGenerationDisabled = true;
            // }
        }

        public void OnGUI()
        {
            GUILayout.BeginHorizontal();

            DrawControls();

            if (position.width > position.height && position.width > k_TwoColumnControlsWidth)
                DrawPreview();

            GUILayout.EndHorizontal();
        }

        public void Update()
        {
            if (m_IsRepaintNeeded)
            {
                //Debug.Log("Repainting...");
                m_IsRepaintNeeded = false;
                Repaint();
            }

            // Update Progress bar is we are Rendering a Font.
            if (m_IsProcessing)
            {
                m_AtlasGenerationProgress = FontEngine.generationProgress;

                m_IsRepaintNeeded = true;
            }

            if (m_IsGlyphPackingDone)
            {
                UpdateRenderFeedbackWindow();

                if (m_IsGenerationCancelled == false)
                {
                    DrawGlyphRectPreviewTexture();
                    Debug.Log("Glyph packing completed in: " + m_GlyphPackingGenerationTime.ToString("0.000 ms."));
                }

                m_IsGlyphPackingDone = false;
            }

            if (m_IsGlyphRenderingDone)
            {
                Debug.Log("Font Atlas generation completed in: " + m_GlyphRenderingGenerationTime.ToString("0.000 ms."));
                m_IsGlyphRenderingDone = false;
            }

            // Update Feedback Window & Create Font Texture once Rendering is done.
            if (m_IsRenderingDone)
            {
                m_IsProcessing = false;
                m_IsRenderingDone = false;

                if (m_IsGenerationCancelled == false)
                {
                    m_AtlasGenerationProgress = FontEngine.generationProgress;
                    m_AtlasGenerationProgressLabel = "Generation completed in: " + (m_GlyphPackingGenerationTime + m_GlyphRenderingGenerationTime).ToString("0.00 ms.");

                    UpdateRenderFeedbackWindow();
                    CreateFontAtlasTexture();

                    // If dynamic make readable ...
                    m_FontAtlasTexture.Apply(false, false);
                }
                Repaint();
            }
        }

        /// <summary>
        /// Method which returns the character corresponding to a decimal value.
        /// </summary>
        /// <param name="sequence"></param>
        /// <returns></returns>
        static uint[] ParseNumberSequence(string sequence)
        {
            List<uint> unicodeList = new List<uint>();
            string[] sequences = sequence.Split(',');

            foreach (string seq in sequences)
            {
                string[] s1 = seq.Split('-');

                if (s1.Length == 1)
                    try
                    {
                        unicodeList.Add(uint.Parse(s1[0]));
                    }
                    catch
                    {
                        Debug.Log("No characters selected or invalid format.");
                    }
                else
                {
                    for (uint j = uint.Parse(s1[0]); j < uint.Parse(s1[1]) + 1; j++)
                    {
                        unicodeList.Add(j);
                    }
                }
            }

            return unicodeList.ToArray();
        }

        /// <summary>
        /// Method which returns the character (decimal value) from a hex sequence.
        /// </summary>
        /// <param name="sequence"></param>
        /// <returns></returns>
        static uint[] ParseHexNumberSequence(string sequence)
        {
            List<uint> unicodeList = new List<uint>();
            string[] sequences = sequence.Split(',');

            foreach (string seq in sequences)
            {
                string[] s1 = seq.Split('-');

                if (s1.Length == 1)
                    try
                    {
                        unicodeList.Add(uint.Parse(s1[0], NumberStyles.AllowHexSpecifier));
                    }
                    catch
                    {
                        Debug.Log("No characters selected or invalid format.");
                    }
                else
                {
                    for (uint j = uint.Parse(s1[0], NumberStyles.AllowHexSpecifier); j < uint.Parse(s1[1], NumberStyles.AllowHexSpecifier) + 1; j++)
                    {
                        unicodeList.Add(j);
                    }
                }
            }

            return unicodeList.ToArray();
        }

        void DrawControls()
        {
            GUILayout.Space(5f);

            if (position.width > position.height && position.width > k_TwoColumnControlsWidth)
            {
                m_ScrollPosition = EditorGUILayout.BeginScrollView(m_ScrollPosition, GUILayout.Width(315));
            }
            else
            {
                m_ScrollPosition = EditorGUILayout.BeginScrollView(m_ScrollPosition);
            }

            GUILayout.Space(5f);

            GUILayout.Label(m_SelectedFontAsset != null ? string.Format("Font Settings [{0}]", m_SelectedFontAsset.name) : "Font Settings", EditorStyles.boldLabel);

            EditorGUILayout.BeginVertical(EditorStyles.helpBox);

            EditorGUIUtility.labelWidth = 125f;
            EditorGUIUtility.fieldWidth = 5f;

            // Disable Options if already generating a font atlas texture.
            EditorGUI.BeginDisabledGroup(m_IsProcessing);
            {
                // FONT SELECTION
                EditorGUI.BeginChangeCheck();
                m_SourceFont = EditorGUILayout.ObjectField("Source Font", m_SourceFont, typeof(Font), false) as Font;
                if (EditorGUI.EndChangeCheck())
                {
                    m_SelectedFontAsset = null;
                    m_IsFontAtlasInvalid = true;
                    m_SourceFontFaces = GetFontFaces();
                    m_SourceFontFaceIndex = 0;
                }

                // FONT FACE AND STYLE SELECTION
                EditorGUI.BeginChangeCheck();
                GUI.enabled = m_SourceFont != null;
                m_SourceFontFaceIndex = EditorGUILayout.Popup("Font Face", m_SourceFontFaceIndex, m_SourceFontFaces);
                if (EditorGUI.EndChangeCheck())
                {
                    m_SelectedFontAsset = null;
                    m_IsFontAtlasInvalid = true;
                }
                GUI.enabled = true;

                // FONT SIZING
                EditorGUI.BeginChangeCheck();
                if (m_PointSizeSamplingMode == 0)
                {
                    m_PointSizeSamplingMode = EditorGUILayout.Popup("Sampling Point Size", m_PointSizeSamplingMode, m_FontSizingOptions);
                }
                else
                {
                    GUILayout.BeginHorizontal();
                    m_PointSizeSamplingMode = EditorGUILayout.Popup("Sampling Point Size", m_PointSizeSamplingMode, m_FontSizingOptions, GUILayout.Width(225));
                    m_PointSize = EditorGUILayout.IntField(m_PointSize);
                    GUILayout.EndHorizontal();
                }
                if (EditorGUI.EndChangeCheck())
                {
                    m_IsFontAtlasInvalid = true;
                }

                // FONT PADDING
                GUILayout.BeginHorizontal();
                EditorGUI.BeginChangeCheck();

                m_PaddingFieldValue = Mathf.Max(EditorGUILayout.FloatField("Padding", m_PaddingFieldValue), 0);

                int selection = m_PaddingMode == PaddingMode.Undefined || m_PaddingMode == PaddingMode.Pixel ? 1 : 0;
                selection = GUILayout.SelectionGrid(selection, k_PaddingOptionLabels, 2);

                if (m_PaddingMode == PaddingMode.Percentage)
                    m_PaddingFieldValue = Mathf.Min((int)(m_PaddingFieldValue + 0.5f), float.MaxValue);

                if (EditorGUI.EndChangeCheck())
                {
                    m_PaddingMode = (PaddingMode)selection + 1;
                    m_IsFontAtlasInvalid = true;
                }
                GUILayout.EndHorizontal();

                // FONT PACKING METHOD SELECTION
                EditorGUI.BeginChangeCheck();
                m_PackingMode = (FontPackingModes)EditorGUILayout.EnumPopup("Packing Method", m_PackingMode);
                if (EditorGUI.EndChangeCheck())
                {
                    m_IsFontAtlasInvalid = true;
                }

                // FONT ATLAS RESOLUTION SELECTION
                GUILayout.BeginHorizontal();
                GUI.changed = false;

                EditorGUI.BeginChangeCheck();
                EditorGUILayout.PrefixLabel("Atlas Resolution");
                m_AtlasWidth = EditorGUILayout.IntPopup(m_AtlasWidth, m_FontResolutionLabels, m_FontAtlasResolutions);
                m_AtlasHeight = EditorGUILayout.IntPopup(m_AtlasHeight, m_FontResolutionLabels, m_FontAtlasResolutions);
                if (EditorGUI.EndChangeCheck())
                {
                    m_IsFontAtlasInvalid = true;
                }

                GUILayout.EndHorizontal();


                // FONT CHARACTER SET SELECTION
                EditorGUI.BeginChangeCheck();
                bool hasSelectionChanged = false;
                m_CharacterSetSelectionMode = EditorGUILayout.Popup("Character Set", m_CharacterSetSelectionMode, m_FontCharacterSets);
                if (EditorGUI.EndChangeCheck())
                {
                    m_CharacterSequence = "";
                    hasSelectionChanged = true;
                    m_IsFontAtlasInvalid = true;
                }

                switch (m_CharacterSetSelectionMode)
                {
                    case 0: // ASCII
                        //characterSequence = "32 - 126, 130, 132 - 135, 139, 145 - 151, 153, 155, 161, 166 - 167, 169 - 174, 176, 181 - 183, 186 - 187, 191, 8210 - 8226, 8230, 8240, 8242 - 8244, 8249 - 8250, 8252 - 8254, 8260, 8286";
                        m_CharacterSequence = "32 - 126, 160, 8203, 8230, 9633";
                        break;

                    case 1: // EXTENDED ASCII
                        m_CharacterSequence = "32 - 126, 160 - 255, 8192 - 8303, 8364, 8482, 9633";
                        // Could add 9632 for missing glyph
                        break;

                    case 2: // Lowercase
                        m_CharacterSequence = "32 - 64, 91 - 126, 160";
                        break;

                    case 3: // Uppercase
                        m_CharacterSequence = "32 - 96, 123 - 126, 160";
                        break;

                    case 4: // Numbers & Symbols
                        m_CharacterSequence = "32 - 64, 91 - 96, 123 - 126, 160";
                        break;

                    case 5: // Custom Range
                        EditorGUILayout.BeginVertical(EditorStyles.helpBox);
                        GUILayout.Label("Enter a sequence of decimal values to define the characters to be included in the font asset or retrieve one from another font asset.", TM_EditorStyles.label);
                        GUILayout.Space(10f);

                        EditorGUI.BeginChangeCheck();
                        m_ReferencedFontAsset = EditorGUILayout.ObjectField("Select Font Asset", m_ReferencedFontAsset, typeof(FontAsset), false) as FontAsset;
                        if (EditorGUI.EndChangeCheck() || hasSelectionChanged)
                        {
                            if (m_ReferencedFontAsset != null)
                            {
                                    m_CharacterSequence = TextCoreEditorUtilities.GetDecimalCharacterSequence(FontAsset.GetCharactersArray(m_ReferencedFontAsset));
                            }

                            m_IsFontAtlasInvalid = true;
                        }

                        // Filter out unwanted characters.
                        char chr = Event.current.character;
                        if ((chr < '0' || chr > '9') && (chr < ',' || chr > '-'))
                        {
                            Event.current.character = '\0';
                        }
                        GUILayout.Label("Character Sequence (Decimal)", EditorStyles.boldLabel);
                        EditorGUI.BeginChangeCheck();
                        m_CharacterSequence = EditorGUILayout.TextArea(m_CharacterSequence, TM_EditorStyles.textAreaBoxWindow, GUILayout.Height(120), GUILayout.ExpandWidth(true));
                        if (EditorGUI.EndChangeCheck())
                        {
                            m_IsFontAtlasInvalid = true;
                        }

                        EditorGUILayout.EndVertical();
                        break;

                    case 6: // Unicode HEX Range
                        EditorGUILayout.BeginVertical(EditorStyles.helpBox);
                        GUILayout.Label("Enter a sequence of Unicode (hex) values to define the characters to be included in the font asset or retrieve one from another font asset.", TM_EditorStyles.label);
                        GUILayout.Space(10f);

                        EditorGUI.BeginChangeCheck();
                        m_ReferencedFontAsset = EditorGUILayout.ObjectField("Select Font Asset", m_ReferencedFontAsset, typeof(FontAsset), false) as FontAsset;
                        if (EditorGUI.EndChangeCheck() || hasSelectionChanged)
                        {
                            if (m_ReferencedFontAsset != null)
                            {
                                    m_CharacterSequence = TextCoreEditorUtilities.GetUnicodeCharacterSequence(FontAsset.GetCharactersArray(m_ReferencedFontAsset));
                            }

                            m_IsFontAtlasInvalid = true;
                        }

                        // Filter out unwanted characters.
                        chr = Event.current.character;
                        if ((chr < '0' || chr > '9') && (chr < 'a' || chr > 'f') && (chr < 'A' || chr > 'F') && (chr < ',' || chr > '-'))
                        {
                            Event.current.character = '\0';
                        }
                        GUILayout.Label("Character Sequence (Hex)", EditorStyles.boldLabel);
                        EditorGUI.BeginChangeCheck();
                        m_CharacterSequence = EditorGUILayout.TextArea(m_CharacterSequence, TM_EditorStyles.textAreaBoxWindow, GUILayout.Height(120), GUILayout.ExpandWidth(true));
                        if (EditorGUI.EndChangeCheck())
                        {
                            m_IsFontAtlasInvalid = true;
                        }

                        EditorGUILayout.EndVertical();
                        break;

                    case 7: // Characters from Font Asset
                        EditorGUILayout.BeginVertical(EditorStyles.helpBox);
                        GUILayout.Label("Type the characters to be included in the font asset or retrieve them from another font asset.", TM_EditorStyles.label);
                        GUILayout.Space(10f);

                        EditorGUI.BeginChangeCheck();
                        m_ReferencedFontAsset = EditorGUILayout.ObjectField("Select Font Asset", m_ReferencedFontAsset, typeof(FontAsset), false) as FontAsset;
                        if (EditorGUI.EndChangeCheck() || hasSelectionChanged)
                        {
                            if (m_ReferencedFontAsset != null)
                            {
                                    m_CharacterSequence = FontAsset.GetCharacters(m_ReferencedFontAsset);
                            }

                            m_IsFontAtlasInvalid = true;
                        }

                        EditorGUI.indentLevel = 0;

                        GUILayout.Label("Custom Character List", EditorStyles.boldLabel);
                        EditorGUI.BeginChangeCheck();
                        m_CharacterSequence = EditorGUILayout.TextArea(m_CharacterSequence, TM_EditorStyles.textAreaBoxWindow, GUILayout.Height(120), GUILayout.ExpandWidth(true));
                        if (EditorGUI.EndChangeCheck())
                        {
                            m_IsFontAtlasInvalid = true;
                        }
                        EditorGUILayout.EndVertical();
                        break;

                    case 8: // Character List from File
                        EditorGUI.BeginChangeCheck();
                        m_CharactersFromFile = EditorGUILayout.ObjectField("Character File", m_CharactersFromFile, typeof(TextAsset), false) as TextAsset;
                        if (EditorGUI.EndChangeCheck())
                        {
                            m_IsFontAtlasInvalid = true;
                        }

                        if (m_CharactersFromFile != null)
                        {
                            Regex rx = new Regex(@"(?<!\\)(?:\\u[0-9a-fA-F]{4}|\\U[0-9a-fA-F]{8})");

                            m_CharacterSequence = rx.Replace(m_CharactersFromFile.text,
                                match =>
                                {
                                    if (match.Value.StartsWith("\\U"))
                                        return char.ConvertFromUtf32(int.Parse(match.Value.Replace("\\U", ""), NumberStyles.HexNumber));

                                    return char.ConvertFromUtf32(int.Parse(match.Value.Replace("\\u", ""), NumberStyles.HexNumber));
                                });
                        }
                        break;
                }

                // FONT STYLE SELECTION
                //GUILayout.BeginHorizontal();
                //EditorGUI.BeginChangeCheck();
                ////m_FontStyle = (FaceStyles)EditorGUILayout.EnumPopup("Font Style", m_FontStyle, GUILayout.Width(225));
                ////m_FontStyleValue = EditorGUILayout.IntField((int)m_FontStyleValue);
                //if (EditorGUI.EndChangeCheck())
                //{
                //    m_IsFontAtlasInvalid = true;
                //}
                //GUILayout.EndHorizontal();

                // Render Mode Selection
                GlyphRenderModeUI selectedUIMode = (GlyphRenderModeUI)m_GlyphRenderMode;

                EditorGUI.BeginChangeCheck();
                selectedUIMode = (GlyphRenderModeUI)EditorGUILayout.EnumPopup("Render Mode", selectedUIMode);
                if (EditorGUI.EndChangeCheck())
                {
                    m_GlyphRenderMode = (GlyphRenderMode)selectedUIMode;
                }

                m_IncludeFontFeatures = EditorGUILayout.Toggle("Get Font Features", m_IncludeFontFeatures);

                EditorGUILayout.Space();
            }

            EditorGUI.EndDisabledGroup();

            if (!string.IsNullOrEmpty(m_WarningMessage))
            {
                EditorGUILayout.HelpBox(m_WarningMessage, MessageType.Warning);
            }

            GUI.enabled = m_SourceFont != null && !m_IsProcessing && !m_IsGenerationDisabled; // Enable Preview if we are not already rendering a font.
            if (GUILayout.Button("Generate Font Atlas") && GUI.enabled)
            {
                if (!m_IsProcessing && m_SourceFont != null)
                {
                    DestroyImmediate(m_FontAtlasTexture);
                    DestroyImmediate(m_GlyphRectPreviewTexture);
                    m_FontAtlasTexture = null;
                    m_SavedFontAtlas = null;
                    m_OutputFeedback = string.Empty;

                    // Initialize font engine
                    FontEngineError errorCode = FontEngine.InitializeFontEngine();
                    if (errorCode != FontEngineError.Success)
                    {
                        Debug.Log("Font Asset Creator - Error [" + errorCode + "] has occurred while Initializing the FreeType Library.");
                    }

                    if (errorCode == FontEngineError.Success)
                    {
                        errorCode = FontEngine.LoadFontFace(m_SourceFont, 0, m_SourceFontFaceIndex);

                        if (errorCode != FontEngineError.Success)
                        {
                            Debug.LogWarning("Unable to load font face for [" + m_SourceFont.name + "]. Make sure \"Include Font Data\" is enabled in the Font Import Settings. You may disable it after creating the static Font Asset.", m_SourceFont);
                        }
                    }

                    // Define an array containing the characters we will render.
                    if (errorCode == FontEngineError.Success)
                    {
                        uint[] characterSet = null;

                        // Get list of characters that need to be packed and rendered to the atlas texture.
                        if (m_CharacterSetSelectionMode == 7 || m_CharacterSetSelectionMode == 8)
                        {
                            // Ensure these characters are always added
                            List<uint> char_List = new List<uint>()
                            {
                                9, // Space
                                95 // Underline
                            };

                            for (int i = 0; i < m_CharacterSequence.Length; i++)
                            {
                                uint unicode = m_CharacterSequence[i];

                                // Handle surrogate pairs
                                if (i < m_CharacterSequence.Length - 1 && char.IsHighSurrogate((char)unicode) && char.IsLowSurrogate(m_CharacterSequence[i + 1]))
                                {
                                    unicode = (uint)char.ConvertToUtf32(m_CharacterSequence[i], m_CharacterSequence[i + 1]);
                                    i += 1;
                                }

                                // Check to make sure we don't include duplicates
                                if (char_List.FindIndex(item => item == unicode) == -1)
                                    char_List.Add(unicode);
                            }

                            characterSet = char_List.ToArray();
                        }
                        else if (m_CharacterSetSelectionMode == 6)
                        {
                            characterSet = ParseHexNumberSequence(m_CharacterSequence);
                        }
                        else
                        {
                            characterSet = ParseNumberSequence(m_CharacterSequence);
                        }

                        m_CharacterCount = characterSet.Length;

                        m_AtlasGenerationProgress = 0;
                        m_IsProcessing = true;
                        m_IsGenerationCancelled = false;

                        GlyphLoadFlags glyphLoadFlags = ((GlyphRasterModes)m_GlyphRenderMode & GlyphRasterModes.RASTER_MODE_HINTED) == GlyphRasterModes.RASTER_MODE_HINTED
                            ? GlyphLoadFlags.LOAD_RENDER
                            : GlyphLoadFlags.LOAD_RENDER | GlyphLoadFlags.LOAD_NO_HINTING;

                        glyphLoadFlags = ((GlyphRasterModes)m_GlyphRenderMode & GlyphRasterModes.RASTER_MODE_MONO) == GlyphRasterModes.RASTER_MODE_MONO
                            ? glyphLoadFlags | GlyphLoadFlags.LOAD_MONOCHROME
                            : glyphLoadFlags;

                        glyphLoadFlags = ((GlyphRasterModes)m_GlyphRenderMode & GlyphRasterModes.RASTER_MODE_COLOR) == GlyphRasterModes.RASTER_MODE_COLOR
                            ? glyphLoadFlags | GlyphLoadFlags.LOAD_COLOR
                            : glyphLoadFlags;


                        //
                        AutoResetEvent autoEvent = new AutoResetEvent(false);

                        // Worker thread to pack glyphs in the given texture space.
                        ThreadPool.QueueUserWorkItem(PackGlyphs =>
                        {
                            // Start Stop Watch
                            m_StopWatch = System.Diagnostics.Stopwatch.StartNew();

                            // Clear the various lists used in the generation process.
                            m_AvailableGlyphsToAdd.Clear();
                            m_MissingCharacters.Clear();
                            m_ExcludedCharacters.Clear();
                            m_CharacterLookupMap.Clear();
                            m_GlyphLookupMap.Clear();
                            m_GlyphsToPack.Clear();
                            m_GlyphsPacked.Clear();

                            // Check if requested characters are available in the source font file.
                            for (int i = 0; i < characterSet.Length; i++)
                            {
                                uint unicode = characterSet[i];
                                uint glyphIndex;

                                if (FontEngine.TryGetGlyphIndex(unicode, out glyphIndex))
                                {
                                    // Skip over potential duplicate characters.
                                    if (m_CharacterLookupMap.ContainsKey(unicode))
                                        continue;

                                    // Add character to character lookup map.
                                    m_CharacterLookupMap.Add(unicode, glyphIndex);

                                    // Skip over potential duplicate glyph references.
                                    if (m_GlyphLookupMap.ContainsKey(glyphIndex))
                                    {
                                        // Add additional glyph reference for this character.
                                        m_GlyphLookupMap[glyphIndex].Add(unicode);
                                        continue;
                                    }

                                    // Add glyph reference to glyph lookup map.
                                    m_GlyphLookupMap.Add(glyphIndex, new List<uint>() { unicode });

                                    // Add glyph index to list of glyphs to add to texture.
                                    m_AvailableGlyphsToAdd.Add(glyphIndex);
                                }
                                else
                                {
                                    // Add Unicode to list of missing characters.
                                    m_MissingCharacters.Add(unicode);
                                }
                            }

                            // Pack available glyphs in the provided texture space.
                            if (m_AvailableGlyphsToAdd.Count > 0)
                            {
                                int packingModifier = ((GlyphRasterModes)m_GlyphRenderMode & GlyphRasterModes.RASTER_MODE_BITMAP) == GlyphRasterModes.RASTER_MODE_BITMAP ? 0 : 1;

                                if (m_PointSizeSamplingMode == 0) // Auto-Sizing Point Size Mode
                                {
                                    // Estimate min / max range for auto sizing of point size.
                                    int minPointSize = 0;
                                    int maxPointSize = (int)Mathf.Sqrt((m_AtlasWidth * m_AtlasHeight) / m_AvailableGlyphsToAdd.Count) * 3;

                                    m_PointSize = (maxPointSize + minPointSize) / 2;

                                    bool optimumPointSizeFound = false;
                                    for (int iteration = 0; iteration < 15 && optimumPointSizeFound == false && m_PointSize > 0; iteration++)
                                    {
                                        m_AtlasGenerationProgressLabel = "Packing glyphs - Pass (" + iteration + ")";

                                        FontEngine.SetFaceSize(m_PointSize);

                                        m_Padding = (int)(m_PaddingMode == PaddingMode.Percentage ? m_PointSize * m_PaddingFieldValue / 100f : m_PaddingFieldValue);

                                        m_GlyphsToPack.Clear();
                                        m_GlyphsPacked.Clear();

                                        m_FreeGlyphRects.Clear();
                                        m_FreeGlyphRects.Add(new GlyphRect(0, 0, m_AtlasWidth - packingModifier, m_AtlasHeight - packingModifier));
                                        m_UsedGlyphRects.Clear();

                                        for (int i = 0; i < m_AvailableGlyphsToAdd.Count; i++)
                                        {
                                            uint glyphIndex = m_AvailableGlyphsToAdd[i];
                                            Glyph glyph;

                                            if (FontEngine.TryGetGlyphWithIndexValue(glyphIndex, glyphLoadFlags, out glyph))
                                            {
                                                if (glyph.glyphRect.width > 0 && glyph.glyphRect.height > 0)
                                                {
                                                    m_GlyphsToPack.Add(glyph);
                                                }
                                                else
                                                {
                                                    m_GlyphsPacked.Add(glyph);
                                                }
                                            }
                                        }

                                        FontEngine.TryPackGlyphsInAtlas(m_GlyphsToPack, m_GlyphsPacked, m_Padding, (GlyphPackingMode)m_PackingMode, m_GlyphRenderMode, m_AtlasWidth, m_AtlasHeight, m_FreeGlyphRects, m_UsedGlyphRects);

                                        if (m_IsGenerationCancelled)
                                        {
                                            DestroyImmediate(m_FontAtlasTexture);
                                            m_FontAtlasTexture = null;
                                            return;
                                        }

                                        //Debug.Log("Glyphs remaining to add [" + m_GlyphsToAdd.Count + "]. Glyphs added [" + m_GlyphsAdded.Count + "].");

                                        if (m_GlyphsToPack.Count > 0)
                                        {
                                            if (m_PointSize > minPointSize)
                                            {
                                                maxPointSize = m_PointSize;
                                                m_PointSize = (m_PointSize + minPointSize) / 2;

                                                //Debug.Log("Decreasing point size from [" + maxPointSize + "] to [" + m_PointSize + "].");
                                            }
                                        }
                                        else
                                        {
                                            if (maxPointSize - minPointSize > 1 && m_PointSize < maxPointSize)
                                            {
                                                minPointSize = m_PointSize;
                                                m_PointSize = (m_PointSize + maxPointSize) / 2;

                                                //Debug.Log("Increasing point size from [" + minPointSize + "] to [" + m_PointSize + "].");
                                            }
                                            else
                                            {
                                                //Debug.Log("[" + iteration + "] iterations to find the optimum point size of : [" + m_PointSize + "].");
                                                optimumPointSizeFound = true;
                                            }
                                        }
                                    }
                                }
                                else // Custom Point Size Mode
                                {
                                    m_AtlasGenerationProgressLabel = "Packing glyphs...";

                                    // Set point size
                                    FontEngine.SetFaceSize(m_PointSize);

                                    m_Padding = (int)(m_PaddingMode == PaddingMode.Percentage ? m_PointSize * m_PaddingFieldValue / 100 : m_PaddingFieldValue);

                                    m_GlyphsToPack.Clear();
                                    m_GlyphsPacked.Clear();

                                    m_FreeGlyphRects.Clear();
                                    m_FreeGlyphRects.Add(new GlyphRect(0, 0, m_AtlasWidth - packingModifier, m_AtlasHeight - packingModifier));
                                    m_UsedGlyphRects.Clear();

                                    for (int i = 0; i < m_AvailableGlyphsToAdd.Count; i++)
                                    {
                                        uint glyphIndex = m_AvailableGlyphsToAdd[i];
                                        Glyph glyph;

                                        if (FontEngine.TryGetGlyphWithIndexValue(glyphIndex, glyphLoadFlags, out glyph))
                                        {
                                            if (glyph.glyphRect.width > 0 && glyph.glyphRect.height > 0)
                                            {
                                                m_GlyphsToPack.Add(glyph);
                                            }
                                            else
                                            {
                                                m_GlyphsPacked.Add(glyph);
                                            }
                                        }
                                    }

                                    FontEngine.TryPackGlyphsInAtlas(m_GlyphsToPack, m_GlyphsPacked, m_Padding, (GlyphPackingMode)m_PackingMode, m_GlyphRenderMode, m_AtlasWidth, m_AtlasHeight, m_FreeGlyphRects, m_UsedGlyphRects);

                                    if (m_IsGenerationCancelled)
                                    {
                                        DestroyImmediate(m_FontAtlasTexture);
                                        m_FontAtlasTexture = null;
                                        return;
                                    }
                                    //Debug.Log("Glyphs remaining to add [" + m_GlyphsToAdd.Count + "]. Glyphs added [" + m_GlyphsAdded.Count + "].");
                                }
                            }
                            else
                            {
                                int packingModifier = ((GlyphRasterModes)m_GlyphRenderMode & GlyphRasterModes.RASTER_MODE_BITMAP) == GlyphRasterModes.RASTER_MODE_BITMAP ? 0 : 1;

                                FontEngine.SetFaceSize(m_PointSize);

                                m_Padding = (int)(m_PaddingMode == PaddingMode.Percentage ? m_PointSize * m_PaddingFieldValue / 100 : m_PaddingFieldValue);

                                m_GlyphsToPack.Clear();
                                m_GlyphsPacked.Clear();

                                m_FreeGlyphRects.Clear();
                                m_FreeGlyphRects.Add(new GlyphRect(0, 0, m_AtlasWidth - packingModifier, m_AtlasHeight - packingModifier));
                                m_UsedGlyphRects.Clear();
                            }

                            //Stop StopWatch
                            m_StopWatch.Stop();