MapCreator.exe — bitmap → .mw4 map authoring tool (deep-dive)¶

Reference record; not an oracle target. See the editor-tools overview.

1. Binary facts¶


File	`reference\MapCreator.exe`
Size	528,384 B (0x81000)
SHA-256	`4f1a37548b352fd36e99a71aded94db13253f9ec84c6d350237b525f5936ea7d`
Toolchain	MSVC6, Linker 6.0, TimeDateStamp 2002-11-26 20:47:03Z
Machine / Subsystem	x86 (0x014C) / GUI (2)
ImageBase	0x00400000
Sections	`.text` RVA 0x1000 VSize 0x68ABB · `.rdata` RVA 0x6A000 · `.data` RVA 0x7C000 VSize 0x78358 (raw 0x3000 — most of `.data` is zero-fill; the tool's literal strings live in the raw part at 0x47C000–0x47C9xx) · `.rsrc` RVA 0xF5000
Imports	MFC42 (135), MSVCRT (76), KERNEL32 (85), USER32 (63), GDI32 (12), ADVAPI32 (12), ole32 (3), MSACM32 (7), VERSION (3), WINMM (5)
Functions	1,556 (Ghidra)

Like NFMEditor, it bundles GameOS and must run from the game install root (Cannot find Language.dll in %s\assets\binaries or %s, this file is required, GameOS build version, Exit:DestroyTextureManager). It also links the Stuff:: engine classes (Stuff::FileStream, Stuff::TreeNodeOf) and a full image-decoding library (TIFF/GIF/TGA/PNG/BMP + zlib + libpng).

2. Purpose and pipeline¶

MapCreator converts a heightfield bitmap + textures into a playable map .mw4. The overall flow (from the writer/handlers):

bitmap (TIF/GIF/TGA/PNG)  ──>  heightfield (256..1024 wide × 256..2048 high,
                               multiple of 256, 24-bit for "interest data")
                                     │
            MapCreator writes (Content\ + Resource\ trees under the game root):
              Content\Maps\<name>                 map definition "info file"
              Content\Maps\<name>\<name>.build     build manifest
              Content\Maps\<name>\tctd.ini         Tctd input config
              Content\Maps\<name>\tctd.ini.bsp     Tctd BSP input config
              Content\textures\maps\...            copied/renamed textures
              Maps\<name>\<name>.instance          instance info
                                     │
            shell:  Tctd /f Content\Maps\<name>\tctd.ini
            shell:  Tctd /f Content\Maps\<name>\tctd.ini -bsp
                                     │
            Tctd.exe builds the final packed map:
              Resource\Maps\<name>.mw4             a #VBD archive (see §7)

Tctd.exe ("Terrain converter/compiler") is an external tool that must be present (Cannot Find Tctd.exe,Make sure this file exists and try again); MapCreator shells out to it with system(). Tctd is what produces the binary terrain/BSP data packed into the final .mw4. The tool then reports Map created successfully. Run Mission Editor to create a mission with this map (or There was an Error in Createing your map [sic] on failure).

3. Layout — .text regions¶

Range	Content
0x401000–0x4072xx	Tool UI + map pipeline (heightfield load/validate, texture pickers, map create/save, Tctd launch)
0x408xxx–0x44Exxx	Bundled GameOS / `Stuff::` engine (file system, textures, DirectX, DirectSound, image codecs)
0x45xxxx–0x465xxx	GameOS config/profile + helpers
0x466Bxx+	Ordinal thunks (MFC/GameOS imports)

The Ghidra inventory names imports Ordinal_XXXX (jmp-thunk table at 0x466B80+). Key ordinal semantics seen in the map code: Ordinal_926/924/ 922 = path-combine string ops, Ordinal_858 = write/create, Ordinal_800 = close, Ordinal_540 = push a "file op" guard, Ordinal_5683 = strrchr, Ordinal_4277 = substring after last \, Ordinal_4129 = strrchr('.'), Ordinal_2818 = sprintf, Ordinal_941 = append to command line, Ordinal_860 = get app path, Ordinal_6334 = _ftol-family.

4. The map definition "info file" (`Content\Maps\<name>`)¶

The map definition is written with the same GameOS info-file format that NFMEditor uses (sections, key=value, case handling — see docs/editor_tools/nfmeditor.md §4). The map file's root carries a gamedata section (all keys below, written by FUN_004021b0 / FUN_004012b0):

Key	Value
`grid`	`<name>.erf` — the grid/terrain source file
`cull`	`nevercull`
`class`	`mechwarrior4::mwmap` — the map class tag
`texturedata`	`<name>.fgd`
`tcffilename`	`<name>.index.tcf`
`waterlevel`	float (water plane height)
`watertexture`	path to water texture
`underwatertexture`	path to underwater texture
`waterdetailtexture`	path to water detail texture
`HudMap`	path to the HUD/minimap texture
`InputPath`	input bitmap path
`MapCenter`	two floats, e.g. `"%.1f %.1f"` (grid center; `this+0x64` × 0x458280 scale const ×2)
`SmoothingPasses`	int (heightfield smoothing passes, `this+0xbc`)
`PolyCount`	int (target poly count, `this+0xc0`)
`HeightField`	heightfield file name
`DeltaY`	float (vertical scale, `this+0xb8`)

Texture/geometry files referenced by the definition: - <name>.fgd — the textured-terrain descriptor, - <name>.index.tcf — the texture-collection/flag file, - <name>.erf — the terrain grid source.

5. Heightfield input rules (from the validator at ~0x401480–0x401780)¶

Rule	Message
exists	`HeightField Does Not Exist` / `Bad Height Field`
width 256..1024	`HeightField Width is too small, must be at least 256` / `HeightField Width is too large, Cannot be larger than 1024`
height 256..2048	`HeightField Height is too small, must be at least 256` / `HeightField Height is too large, must be at most 2048`
both multiple of 256	`HeightField has incorrect size, must be a multiple of 256 i.e. 256,512,768,1024...`
24-bit when "Interest data" used	`HeightField must be 24-bit while using "Interest data"`

File dialog filter: Bitmap Images (*.tif,*.gif,*.tga,*.png)|*.tif;*.gif;*.tga;*.png||. The image decoder handles TIFF (Tiff Error-*), GIF, TGA, PNG (libpng), BMP, JPEG (via ijl10.dll).

6. Texture rules¶

Texture	Constraint
Terrain texture	must exist, must be valid (`Terrain Texture Does Not Exist` / `Bad Terrain Texture`); size must equal the heightfield: `For a Heightfield of %ix%i Terrain Texture should be %ix%i`
Detail texture	`Detail Texture Does Not Exist` / `Bad Detail Texture`; `Detail Texture MUST be 256x256`
Water / water-detail / underwater	must exist; all `MUST be 256x256` (`Water Texture Texture MUST be 256x256` [sic], etc.)
Selection	`FGD Files (.fgd)\|.fgd\|\|` dialog for the FGD; textures written under `Content\textures\maps\` with the `%s\%s.Tga` / `%s\%c%c\%s_%c%c_0_0000.Tga` naming pattern

7. The final map archive — `Resource\Maps\<name>.mw4` is a #VBD¶

The shipped maps (e.g. carps01.mw4, 7–27 MB) are #VBD v4 archives — the container documented in include/mw4/vbd.h. Verified on carps01.mw4: sig #VBD, version 4, key1==key2==0x108, filetime, flags 1/1, archive path resource\maps\carps01.mw4 (25 chars incl. extension).

Two observations beyond vbd.h:

The directory is multi-group. After the header/path, the directory is organised as a sequence of blocks, each block = a path + its member entries: e.g. maps\carps01\carps01.instance, then entry rows textures\composttexture\arctic01_color_rock_active.bid, textures\composttexture\alpine01_color_rockfaceshale_active.bid, ... — one per map asset. entry_count=63 in the header is a capacity/count field, not the actual member count of every archive.
Members are compressed binary. The .instance/.bid members are binary, high-entropy (LZW-style, uncompressed_size > stored_size; the decompressor is the game's FUN_006FC220, see AGENTS.md "Compression codec — LZW"). data_off is relative to dir_file_offset and members are laid out contiguously (next.data_off == prev.data_off + prev.stored_size).

So MapCreator itself never writes a #VBD — it writes the info-file definition + textures and lets Tctd.exe produce the packed archive.

8. Key functions¶

VA	Size	Role
0x004012b0	514	Map-definition metadata writer (InputPath, MapCenter, SmoothingPasses, PolyCount, HeightField, DeltaY)
0x00401750	—	Heightfield load (file dialog `.tif;.gif;.tga;.png`)
~0x401480–0x401780	—	Heightfield validator (size rules §5; not a Ghidra-recognised function)
0x004021b0	1869	Map definition writer (`gamedata` section: grid/cull/class/texturedata/tcffilename/water*/HudMap)
0x00403720	1684	Create-map orchestrator: writes definition + `.build` + `.instance`, copies textures, calls the Tctd launcher
0x00403dc0	266	`.build` manifest writer (`Content\Maps\<name>\<name>.build`)
0x00403ed0	~900	Create-map command handler: name sanitise/validate (`Give the map a valid name`), overwrite prompt (`A map by this name exists, OverWrite?`), success/error messages (region, not a Ghidra function)
0x00404220	486	Tctd.exe launcher: option flags (`/i`, `/s`, `/y`, `/uid`, `/p`) + `system("Tctd /f Content\Maps\<name>\tctd.ini")` + `system("Tctd /f Content\Maps\<name>\tctd.ini -bsp")`; missing-Tctd error
0x00404cb0 / 0x00405790 / 0x00405870 / 0x00405970	—	texture pickers (FGD / water / detail dialogs)
0x004095c0 / 0x00409690 / 0x00409740	60/43/43	info-tree set string / int / float
0x0040a530 / 0x0040a6b0 / 0x0040ad30	171/152/84	info-file open / close / free
0x0040b6b0 / 0x0040b6d0 / 0x0040b890	31/301/218	info-tree helpers (gamedata lookup, subtree)
0x00415f00	161	file-exists check (Tctd.exe)

(The info-file parse/serialize library itself is the same GameOS family as NFMEditor's §4 map — the parser here is the MapCreator's bundled copy.)

9. Bundled engine / libraries¶

GameOS: file system (Stuff::FileStream, memory-mapped files, Too many files, File '%s' is still open), texture manager (InitializeTextureManager called twice!, Exit:DestroyTextureManager, texture filter/format diagnostics), Direct3D/DirectDraw/DirectSound/DirectInput error tables, driver/registry dump (VideoCard.txt, Driver version, \Config\Platform), Language.dll loader, DirectPlay (DPERR_*), sound (acmStreamOpen, MSADPCM/PCM only).
Image codecs: TIFF ((Is Tiff)Invalid File, Tiff Error-Wrong Version), GIF, TGA (Only 256 color palletized, 24 or 32 bit TGA files supported), PNG (libpng — Not a PNG file, Incompatible libpng version), BMP ("..." is an invalid .BMP file), JPEG (ijl10). Plus zlib. The (Create Fade) / (MaskTo) / (MakeRGB) / (UnDifference) / (Deinterlace) strings are a generic image-processing helper library.
Stuff:: engine classes: Stuff::FileStream, Stuff::TreeNodeOf.
MAPI support (MAPISendMail, Bad MAPI32.DLL) and the same RAID/SQL connection string as NFMEditor (DRIVER={SQL Server};...).

10. Notable strings (VA → value, all in `.data` raw 0x47C000+)¶

0x47C2C0 Content\Maps\ · 0x47C2C8 Maps\ · 0x47C2D0 HudMap · 0x47C2D8/0x47C2EC/0x47C2F1 waterdetailtexture/underwatertexture/ watertexture · 0x47C310 maps\ · 0x47C318 waterlevel · 0x47C324 tcffilename · 0x47C33C texturedata · 0x47C358 mechwarrior4::mwmap · 0x47C350 class · 0x47C374/0x47C36C nevercull/cull · 0x47C380/ 0x47C388 grid/.erf · 0x47C398 gamedata · 0x47C330 .index.tcf · 0x47C348 .fgd · 0x47C3F0 textures.hint · 0x47C400 Content\Textures\ (also Content\Textures\Maps\) · 0x47C450 %s\%s.Tga · 0x47C4B0 TexturePool · 0x47C4E8 .mw4 · 0x47C4F0 Resource\Maps\ · 0x47C500 .build · 0x47C508 Content\ · 0x47C514 Maps\%s\%s.build · 0x47C444/ 0x47C4DC .instance/instance · 0x47C2B4 \tctd.ini · 0x47C68C \tctd.ini -bsp · 0x47C69C Tctd /f Content\Maps\ · 0x47C6B4 Tctd.exe · 0x47C6C0/C4/C8/CC/D4 /i /s /y /uid /p · 0x47C0A0 \ · 0x47C528 There was an Error in Createing your map · 0x47C564 Map created successfully. Run Mission Editor to create a mission with this map · 0x47C5EC A map by this name exists, OverWrite? · 0x47C628 Give the map a valid name · 0x47C64C Cannot Find Tctd.exe,Make sure this file exists and try again · 0x47C244 Bitmap Images (*.tif,*.gif,*.tga,*.png)|*.tif;*.gif;*.tga;*.png|| · 0x47C81C FGD Files (*.fgd)|*.fgd||

Heightfield/texture rule strings: 0x47C14C/0x47C184/0x47C1BC/0x47C1F8 height too large/small, width too large/small · 0x47C0C0 multiple-of-256 · 0x47C114 24-bit-for-interest-data · 0x47C0A4/0x47C230 HeightField Does Not Exist/Bad Height Field · 0x47C714/0x47C734 Terrain Texture Does Not Exist/Bad Terrain Texture · 0x47C77C Detail Texture MUST be 256x256 · 0x47C7E0 For a Heightfield of %ix%i Terrain Texture should be %ix%i · 0x47C924 Water Texture Texture MUST be 256x256

11. Key data-structure take-aways¶

MapCreator writes an info-file map definition tagged class=mechwarrior4::mwmap (the gamedata section keys in §4) — the same GameOS key/value grammar as .nfm.
The heavy lifting (binary terrain/BSP + final packing into the #VBD .mw4) is delegated to the external Tctd.exe; MapCreator only stages inputs and textures. The shipped Resource\Maps\*.mw4 are therefore Tctd's output, not MapCreator's.
Heightfields are strictly bounded: 256..1024 wide, 256..2048 high, both a multiple of 256, 24-bit when "interest data" is enabled.
Terrain texture must match the heightfield size; detail/water textures are fixed 256×256.
The #VBD map archives use a multi-group directory (each asset group has its own path prefix) — a layout detail not captured in vbd.h, whose entry_count=63 field is not the member count. Worth a follow-up update to include/mw4/vbd.h.