public static void SaveExpansionPdb(string strFile, Document[] adoc, string strVersion)
        {
            // First save all level docs

            //annoying
            //DocManager.SaveAllModified(typeof(LevelDoc));

            // Remember active document

            LevelDoc lvldActive = (LevelDoc)DocManager.GetActiveDocument(typeof(LevelDoc));

            // Save documents adoc in an expansion .pdb. Expansion .pdbs need:
            // - .lvl, .tmap, .trmap, but not .tsets since these come from game .pdbs
            // - need a version.txt
            // - need an if demo trigger check "inserted" at save time
            // - .pdb needs WARI creator, ADD1 type
            // - data should be compressed for obfuscation purposes

            PdbPacker pdbp = new PdbPacker();

            // Add version.txt

            byte[] abT = new byte[strVersion.Length + 1];
            for (int n = 0; n < strVersion.Length; n++)
                abT[n] = (byte)strVersion[n];
            abT[abT.Length - 1] = 0;
            pdbp.Add(new PdbPacker.File("version.txt", abT));

            // Load res.h from embedded resource in prep for pre-process

            System.Reflection.Assembly ass = typeof(GobImage).Module.Assembly;
            Stream stmResDotH = ass.GetManifestResourceStream("m.EmbeddedResources." + "res.h");
            if (stmResDotH == null)
                throw new Exception("Cannot load res.h");

            // Compile levels

            Random rand = new Random();
            ArrayList alsTileSets = new ArrayList();
            foreach (LevelDoc lvld in adoc) {
                // Need to do this unfortunately; some of the "saving" code relies on what the "active" document
                // is!!

                DocManager.SetActiveDocument(typeof(LevelDoc), lvld);

                TemplateDoc tmpd = lvld.GetTemplateDoc();

                // Get appropriate TileSet, or make one if this map
                // uses a new tile collection

                TileSet tset = null;
                foreach (TileSet tsetT in alsTileSets) {
                    if (tsetT.TemplateDoc == tmpd) {
                        tset = tsetT;
                        break;
                    }
                }

                // Create new tile set if none found

                if (tset == null) {
                    tset = new TileSet(tmpd, tmpd.GetName() + ".tset");
                    alsTileSets.Add(tset);
                }

            #if false
                // Generate base file name for this level (this is never user-visible, but it should be
                // as unique as possible

                char[] achBase = new char[16];
                for (int n = 0; n < achBase.Length; n++) {
                    int nT = rand.Next() % (26 + 10);
                    if (nT < 26) {
                        achBase[n] = (char)(nT + 97);
                    } else {
                        achBase[n] = (char)(nT + 48 - 26);
                    }
                }
                if (lvld.MaxPlayers > 1) {
                    achBase[0] = 'm';
                    achBase[1] = '_';
                }
                string strBase = new String(achBase);
            #else
                // This isn't unique which can cause problems due to how packfiles work.
                // Could change packfile api to accept .pdb parameter.
                // Note1: set next mission action requires predictable filename
                // Note2: mission sorting is based on filename, not title
                // Could put lots of "support" in to fix these problems, or just ship
                // it like this.
                //
                // Hack: filename length 29
                // Maximum extension on filename: 7

                string strBase = lvld.Title;
                if (strBase.Length > 29 - 7)
                    strBase = strBase.Substring(0, 29 - 7);

                // If multiplayer, add "m_" to the name by losing the last two characters
                // so sort order is preserved

                if (lvld.MaxPlayers > 1)
                    strBase = "m_" + strBase.Substring(0, strBase.Length - 2);
            #endif

                // Get tile map file for this level

                MemoryStream stmTmap = new MemoryStream();
                TileMap tmap = TileMap.CreateFromImage(tset, lvld.GetMapBitmap(tmpd.TileSize, tmpd, true), tmpd.TileSize);
                tmap.Save(stmTmap);
                string strTmap = strBase + ".tmap";
                pdbp.Add(new PdbPacker.File(strTmap, stmTmap.ToArray()));
                stmTmap.Close();

                // Get the terrain map file for this level

                MemoryStream stmTRmap = new MemoryStream();
                TerrainMap trmap = new TerrainMap(lvld.GetTerrainMap(tmpd.TileSize, tmpd, false));
                trmap.Save(stmTRmap);
                string strTRmap = strBase + ".trmap";
                pdbp.Add(new PdbPacker.File(strTRmap, stmTRmap.ToArray()));
                stmTRmap.Close();

                // Save .ini file for this level doc

                MemoryStream stmLvld = new MemoryStream();
                lvld.SaveIni(stmLvld, -1, strTmap, strTRmap, tmpd.GetName() + ".palbin", true);

                // Pre-process

                stmLvld.Seek(0, SeekOrigin.Begin);
                MemoryStream stmPreprocessed = Misc.PreprocessStream(stmLvld, stmResDotH);
                stmPreprocessed.Seek(0, SeekOrigin.Begin);
                Ini iniPreProcessed = new Ini(stmPreprocessed);

                MemoryStream stmLvldPreProcessedBinary = new MemoryStream();
                iniPreProcessed.SaveBinary(stmLvldPreProcessedBinary);
                stmLvldPreProcessedBinary.Close();

                string strLvlName = lvld.OutputFilename;
                if (strLvlName == null) {
                    strLvlName = strBase + ".lvl";
                }
                pdbp.Add(new PdbPacker.File(strLvlName, stmLvldPreProcessedBinary.ToArray()));
                stmLvldPreProcessedBinary.Close();
            }
            stmResDotH.Close();

            // Restore active document

            if (lvldActive != null)
                DocManager.SetActiveDocument(typeof(LevelDoc), lvldActive);

            // Now save out pdb

            pdbp.Save(strFile, "WARI", "ADD2");
        }