LyricDisplay.cs

using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using UnityEngine.TextCore.LowLevel;
using TMPro;
using System.Globalization;

class LyricText : MonoBehaviour
{
    [SerializeField]
    TextMeshProUGUI currentPhraseDisplay;

    [SerializeField]
    TextMeshProUGUI nextPhraseDisplay;

    [SerializeField]
    TextMeshProUGUI fadePhraseDisplay;

    [SerializeField]
    Font[] fallbackFonts;

    TMP_FontAsset dynamicFont;

    List<Phrase> phrases;

    private IEnumerable<uint> GetUTF32Chars(string s)
    {
        var tee = StringInfo.GetTextElementEnumerator(s);

        while (tee.MoveNext())
        {
            yield return (uint)char.ConvertToUtf32(s, tee.ElementIndex);
        }
    }

    private string UTF32ToString(uint[] input)
    {
        string[] output = new string[input.Length];

        for (int i = 0; i < input.Length; ++i)
        {
            output[i] = char.ConvertFromUtf32((int)input[i]);
        }

        return string.Concat(output);
    }

    private TMP_FontAsset LoadFontAsset(Font sourceFont, uint[] characters, out uint[] missingGlphs)
    {
        TMP_FontAsset dynamicFont = TMP_FontAsset.CreateFontAsset(sourceFont, 90, 9, GlyphRenderMode.SDFAA, 1024, 1024, AtlasPopulationMode.Dynamic);

        dynamicFont.TryAddCharacters(characters, out missingGlphs);

        if (missingGlphs != null && missingGlphs.Length != 0)
        {
            Debug.Log($"Characters not supported by font: {UTF32ToString(missingGlphs)}");
        }
        return dynamicFont;
    }

    private IEnumerable<uint> GetLyricUTF32Chars()
    {
        foreach (Phrase phrase in phrases)
        {
            foreach (uint codePoint in GetUTF32Chars(phrase.text))
            {
                yield return codePoint;
            }
        }
    }

    public void SetupFont()
    {
        uint[] startingGlyphs = GetLyricUTF32Chars().Distinct().ToArray();
        uint[] remainingGlyphs = startingGlyphs;

        List<TMP_FontAsset> fontAssets = new List<TMP_FontAsset>();

        foreach (Font font in fallbackFonts)
        {
            fontAssets.Add(LoadFontAsset(font, remainingGlyphs, out remainingGlyphs));
            if (remainingGlyphs == null)
                break;
        }

        Debug.Log($"starting glyphs: {UTF32ToString(startingGlyphs)}");

        dynamicFont = fontAssets[0];

        for (int i = 1; i < fontAssets.Count; ++i)
        {
            dynamicFont.fallbackFontAssetTable.Add(fontAssets[i]);
        }

        currentPhraseDisplay.font = dynamicFont;
        nextPhraseDisplay.font = dynamicFont;
        fadePhraseDisplay.font = dynamicFont;
    }
}