Convert BMFont txt file to Unity font. XML version: Create UGUI Customize Font – 建立 UGUI 自定義字型 – 阿祥的開發日常 https://tedsieblog.wordpress.com/2016/07/11/create-ugui-customize-font/

BitmapFontExporter.cs

using System;
using System.IO;
using System.Text.RegularExpressions;
using UnityEditor;
using UnityEngine;

public class BitmapFontExporter : ScriptableWizard
{
    public TextAsset fontFile;
    public Texture2D textureFile;

    [MenuItem("Tools/BitmapFontExporter/Create")]
    private static void CreateFont()
    {
        ScriptableWizard.DisplayWizard<BitmapFontExporter>("Create Font");
    }

    private void OnWizardCreate()
    {
        if (fontFile == null || textureFile == null)
        {
            return;
        }

        string path = EditorUtility.SaveFilePanelInProject("Save Font", fontFile.name, "", "");

        if (!string.IsNullOrEmpty(path))
        {
            ResolveFont(path);
        }
    }

    private void ResolveFont(string exportPath)
    {
        if (!fontFile) throw new UnityException(fontFile.name + "is not a valid font-txt file");

        Font font = new Font();

        string fontPath = AssetDatabase.GetAssetPath(fontFile);
        var sr = new StreamReader(fontPath);

        // info
        string info = sr.ReadLine();
        if (info == null)
        {
            Debug.LogError(string.Format("Font {0} is not a valid file", fontPath));
            return;
        }
        string face = Regex.Match(info, "face=\"(.*?)\"").Groups[0].Value;

        // common
        sr.ReadLine();
        // page
        sr.ReadLine();
        // chars
        var count = Convert.ToInt32(sr.ReadLine().Substring(12));

        CharacterInfo[] charInfos = new CharacterInfo[count];

        for (int cnt = 0; cnt < count; cnt++)
        {
            string node = sr.ReadLine();
            var match = Regex.Match(node,
                "char id=(-?\\d+)\\s+x=(-?\\d+)\\s+y=(-?\\d+)\\s+width=(-?\\d+)\\s+height=(-?\\d+)\\s+xoffset=(-?\\d+)\\s+yoffset=(-?\\d+)\\s+xadvance=(-?\\d+)\\s+page=(-?\\d+)\\s+chnl=(-?\\d+)");
            CharacterInfo charInfo = new CharacterInfo();

            charInfo.index = ToInt(match.Groups[1].Value);
            // Disable obsolete api warning for compatibility
#pragma warning disable 0618
            charInfo.width = ToInt(match.Groups[8].Value);
            charInfo.uv = GetUV(match.Groups[2].Value, match.Groups[3].Value, match.Groups[4].Value, match.Groups[5].Value);
            charInfo.vert = GetVert(match.Groups[5].Value, match.Groups[7].Value, match.Groups[4].Value, match.Groups[5].Value);
#pragma warning restore 0618

            charInfos[cnt] = charInfo;
        }

        Shader shader = Shader.Find("Unlit/Transparent");
        Material material = new Material(shader);
        material.mainTexture = textureFile;
        AssetDatabase.CreateAsset(material, exportPath + ".mat");

        font.material = material;
        font.name = face;
        font.characterInfo = charInfos;
        AssetDatabase.CreateAsset(font, exportPath + ".fontsettings");
    }

    private Rect GetUV(string x, string y, string width, string height)
    {
        Rect uv = new Rect();

        uv.x = ToFloat(x) / textureFile.width;
        uv.y = ToFloat(y) / textureFile.height;
        uv.width = ToFloat(width) / textureFile.width;
        uv.height = ToFloat(height) / textureFile.height;
        uv.y = 1f - uv.y - uv.height;

        return uv;
    }

    private Rect GetVert(string xoffset, string yoffset, string width, string height)
    {
        Rect uv = new Rect();

        uv.x = ToFloat(xoffset);
        uv.y = ToFloat(yoffset);
        uv.width = ToFloat(width);
        uv.height = ToFloat(height);
        uv.y = -uv.y;
        uv.height = -uv.height;

        return uv;
    }

    private int ToInt(string value)
    {
        return Convert.ToInt32(value);
    }

    private float ToFloat(string value)
    {
        return (float)ToInt(value);
    }
}