C# pbm decode / gocr cache explorer

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace textblit
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        Ptn[] ptn;
        private class Ptn
        {
            public string fn;
            public string asc;
            public Ptn(string f, string a)
            {
                fn = f;
                asc = a;
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Timer t = new Timer();
            t.Interval = 100;
            t.Start();
            t.Tick += t_Tick;
        }

        void t_Tick(object sender, EventArgs e)
        {
            ((Timer)sender).Stop();
            gp.BackgroundImage = null;
            List<Ptn> lptn = new List<Ptn>();
            string[] strs = System.IO.File.ReadAllLines(@"C:\inc\b64\db\dbdb.lst");
            foreach (string str in strs)
            {
                int i = str.IndexOf(' ');
                string a = str.Substring(i + 1);
                lptn.Add(new Ptn(str.Substring(0, i),
                    a.Length == 1 ? a :
                    a[0] == '"' ? a.Substring(1, a.Length - 2) :
                    ((char)Convert.ToInt32(a, 16)).ToString()));
            }
            ptn = lptn.ToArray();
            Array.Sort(ptn, (x,y) =>
                x.asc.Length == 1 && y.asc.Length == 1 ? x.asc[0] - y.asc[0] :
                x.asc.Length == y.asc.Length ? x.asc.CompareTo(y.asc) :
                x.asc.Length - y.asc.Length);
            set(0);
        }
        void fuck()
        {
            Bitmap bsrc = new Bitmap("src.png");
            Bitmap bout = new Bitmap(bsrc.Width * 2, bsrc.Height, bsrc.PixelFormat);
            BitmapData dsrc = bsrc.LockBits(new Rectangle(0, 0, bsrc.Width, bsrc.Height), ImageLockMode.ReadOnly, bsrc.PixelFormat);
            BitmapData dout = bsrc.LockBits(new Rectangle(0, 0, bout.Width, bout.Height), ImageLockMode.WriteOnly, bout.PixelFormat);
            int sz = dsrc.Stride * dsrc.Height;
            byte[] ci = new byte[dsrc.Stride];
            byte[] co = new byte[dout.Stride];
            for (int x = 0; x < ci.Length; x++) ci[x] = 255;
            for (int x = 0; x < co.Length; x++) co[x] = 255;
            for (int y = 0; y < bsrc.Height; y++)
            {
                System.Runtime.InteropServices.Marshal.Copy(dsrc.Scan0, ci, dsrc.Stride * y, dsrc.Stride);
                for (int x = 0; x < bsrc.Width; x++)
                {
                    co[x] = ci[x];
                }
                System.Runtime.InteropServices.Marshal.Copy(co, 0, dout.Scan0 + dout.Stride * y, dout.Stride);
            }
            bsrc.UnlockBits(dsrc);
            bout.UnlockBits(dout);
            bout.Save("test.bmp");
        }

        private void gn_KeyDown(object sender, KeyEventArgs e)
        {
            int i = 0;
            try
            {
                i = Convert.ToInt32(gn.Text);
                if (e.KeyCode == Keys.Down) i--;
                if (e.KeyCode == Keys.Up) i++;
                set(i);
            }
            catch { }
        }

        private void gs_KeyUp(object sender, KeyEventArgs e)
        {
            int dir = 0;
            int ofs = 0;
            Int32.TryParse(gn.Text, out ofs);
            if (e.KeyCode == Keys.Down) dir--;
            if (e.KeyCode == Keys.Up) dir++;
            if (dir != 0)
            {
                for (ofs += dir; dir > 0 ? ofs < ptn.Length : ofs > 1; ofs += dir)
                {
                    if (gs.Text == ptn[ofs].asc)
                    {
                        set(ofs);
                        return;
                    }
                }
            }
            if (e.KeyCode == Keys.Enter)
            {
                ptn[ofs].asc = gs.Text;
                set(ofs);
            }
        }

        void set(int i)
        {
            byte[] data = System.IO.File.ReadAllBytes(@"C:\inc\b64\db\db" + ptn[i].fn);
            gn.Text = i.ToString();
            gt.Text = gs.Text = ptn[i].asc;
            gs.SelectionStart = gs.Text.Length;
            label1.Text = ptn[i].fn;
            string res = null;
            int a = 3;
            for (; a < 90; a++)
            {
                if (data[a] == '\n')
                {
                    res = Encoding.UTF8.GetString(data, 3, a - 3);
                    break;
                }
            }
            if (string.IsNullOrEmpty(res)) return;
            string[] ress = res.Split(' ');
            Bitmap bm = new Bitmap(
                Convert.ToInt32(ress[0]),
                Convert.ToInt32(ress[1]));

            int x = 0, y = 0; //a--;
            while (++a < data.Length)
            {
                for (int n = 7; n >= 0; n--)
                {
                    bool black = (data[a] & (1 << n)) == 0;
                    bm.SetPixel(x, y, black ? Color.Black : Color.White);
                    if (++x >= bm.Width)
                    {
                        x = 0;
                        n = 0;
                        if (++y >= bm.Height)
                        {
                            goto lolgoto;
                        }
                    }
                }
            }

        lolgoto:
            if (gp.BackgroundImage != null)
                gp.BackgroundImage.Dispose();
            gp.BackgroundImage = bm;
        }
    }
}