DoomGeo is a Neo Geo AES research prototype that pushes Doom-like gameplay through the hardware the way the machine wants to draw: sprite strips, pre-baked graphics, fix-layer UI, and very small runtime data.
It is not a framebuffer Doom source port. The build tools read Doom-format WAD data offline, convert the map and assets into Neo Geo-friendly structures, and the 68000 runtime drives the scene by updating sprite control blocks rather than drawing pixels.
| Area | Status |
|---|---|
| WAD conversion | Converts E1M1 map lumps, player start, doors, exits, secrets, damaging sectors, texture classes, sector heights, and runtime things into a centered 48x36 Neo Geo grid for the normal experimental WAD path. The current default playable ROM uses the lower-complexity handmade DOOM_SIMPLE_MAP=1 showcase instead, so the menu boots a stable 16x16 NGRayEx-style level with Doom HUD/weapons/things. WAD-derived 16x16 chunks generated by tools/doom_chunk_convert.py remain available as an opt-in experiment through the chunk targets. Generated map arrays are split into doom_map_generated.h declarations and doom_map_generated.c table definitions. |
| Rendering | Default playable build uses the original NGRayEx-style 80-column, full-height grid DDA proportions, with Doom wall/door atlases, HUD, weapons, world sprites, and pre-baked moving floor/ceiling planes. The older 48x36 converted-WAD renderer remains available with DOOM_SIMPLE_MAP=0 for comparison and converter work. Failed/missing or wall-hidden sprite strips no longer consume visible thing slots. |
| HUD | Doom STBAR, face frames, key/weapon indicators, large red status digits, and compact ammo counters. |
| Weapons | Fist, pistol, shotgun, chaingun, rocket launcher, plasma rifle, BFG, and chainsaw have playable runtime paths when the selected IWAD supplies the matching psprite art. The default shareware build masks unavailable plasma/BFG psprites instead of drawing fake placeholders; explicit Freedoom builds exercise the full redistributable weapon-art path. |
| RIPDOOM-lite geometry | make ripdoom-map ripdoom-check ripdoom-runtime-check ripdoom-render-check emits and validates a compact, SNES-inspired geometry package from real Doom VERTEXES, LINEDEFS, SIDEDEFS, SECTORS, SEGS, SSECTORS, NODES, REJECT, BLOCKMAP, and THINGS, plus a linedef-to-seg index for cheap local renderer candidates. DOOM_RIPDOOM_RENDER=1 compiles the C BSP/blockmap query layer and an opt-in local ray-hit wall renderer into a ROM; opened generated chunk doors and lifts are skipped by the RIPDOOM ray path so collision and visual state stay aligned. This is the next converter contract for BSP/seg-driven rendering; the render mode is experimental and not the default gameplay path yet. |
| Gameplay | Pickups, keys, timed powerups, doors, exits, secrets, hurt/bonus/muzzle feedback, monsters with baked Doom rotation frames, barrels, corpses, drops, projectiles, and compact AI are present. Two-sided lines use Doom-like player-height and step-height checks, so small stairs stay passable while high ledges remain blocking. make combat-test-rom, make encounter-test-rom, make monster-gallery-rom, and make arsenal-test-rom boot isolated verification ROMs. |
| Map | The main playable map is now a compact handmade 16x16 showcase with enemies, pickups, a key door, and an exit, chosen because it is currently much more playable on Neo Geo sprite-strip constraints than the full converted E1M1 map. The converted-WAD and chunked map paths remain buildable experiments. Opening and normal closing spread fix-layer work across frames instead of blocking on full one-frame redraws. |
| Flow | Normal ROMs boot to a fix-layer block-letter intro/menu and start the current compiled playable map with B or D. Focused verification ROMs skip the intro so smoke captures still launch directly into their scenario. |
| Audio | Null sound path only. YM2610/Z80 sound and music conversion are not implemented yet. |
| Browser build | GitHub Pages package runs the ROM through EmulatorJS/FBNeo, plus a separate 68000 ASM demo build. |
| Motion showcase |
|---|
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| Intro/menu | Current gameplay |
|---|---|
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| Minimap overlay |
|---|
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| Combat test ROM | Shotgun fire frame |
|---|---|
 |
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| Combat kill smoke |
|---|
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| Sample encounter | Sample scout route |
|---|---|
 |
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| Melee test ROM | Monster gallery ROM |
|---|---|
 |
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| Arsenal test ROM | Held-C weapon shortcut |
|---|---|
 |
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| Death/drop test ROM |
|---|
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| Powerup test ROM |
|---|
 |
The checked-in screenshot and motion-GIF set is currently captured from the
optimized hand-authored sample map, not from the experimental converted-WAD
renderer.
Native Doom comparison tooling remains available through tools/capture_compare.sh
for future converter work.
| Input | Action |
|---|---|
| D-pad Up / Down on intro menu | Move menu selection |
| B or D on intro menu | Confirm selection / start compiled map |
| A on submenu | Return to the main intro menu |
| D-pad Up / Down | Move forward/back |
| D-pad Left / Right | Turn |
| Hold A + Left/Right | Strafe |
| B | Fire weapon |
| C | Cycle to next ready weapon |
| Hold C + D-pad | Fast weapon shortcuts: Up shotgun, Right chaingun, Down rocket, Down+Right plasma, Down+Left BFG, Left close/basic. Direction-first and C-first chords both work. |
| D | Use facing door |
| Hold A + C | Toggle minimap |
| D after DEAD/EXIT | Restart compiled level |
Default GnGeo keyboard mapping used by the repo launchers: Neo Geo A=Z,
B=X, C=A, D=S, Start=1, Coin=3, and movement uses the arrow keys.
That means the minimap toggle is keyboard Z + A.
The default make cart path now boots the hand-authored sample map. For the
experimental converted E1M1 chunk/RIPDOOM-lite path, use:
make chunk-playable-rom DOOM_IWAD=/path/to/Doom1.WAD
make chunk-playable-gngeo DOOM_IWAD=/path/to/Doom1.WADThis differs from chunk-movement-test-rom, which intentionally overrides
input with a scripted forward-walk sequence for regression testing.
The default GnGeo keyboard mapping is:
| Neo Geo | Keyboard |
|---|---|
| A / B / C / D | Z / X / A / S |
| Start / Coin | 1 / 3 |
| D-pad | Arrow keys |
| Menu | Esc |
Tools and downloaded WAD data are kept under .tools/, which is ignored by git.
The default build uses the Doom 1 shareware WAD zip. To compare against an owned
Doom 1 IWAD, pass DOOM_IWAD=/path/to/DOOM.WAD; to test the full
redistributable weapon-art path explicitly, pass DOOM_IWAD=$(FREEDOOM_ZIP).
python3 tools/doomgeo_build.py install
python3 tools/doomgeo_build.py doctor
python3 tools/doomgeo_build.py build
SDL_VIDEODRIVER=x11 make gngeoUseful variants:
make cart # default simple 16x16 showcase, DOOM_DETAIL=quality
make cart DOOM_DETAIL=clarity # simple showcase with clarity-tier assets
make cart DOOM_DETAIL=quality # simple showcase with quality-tier assets
make cart DOOM_DETAIL=balanced # simple showcase with balanced-tier assets
make cart DOOM_DETAIL=speed # simple showcase with speed-tier assets
make cart DOOM_SIMPLE_MAP=0 # experimental converted-WAD grid renderer
make route-check
make DOOM_MAP=E1M1 BUILDDIR=build/chunk-e1m1 chunk-map chunk-route-check chunk-visibility-check chunk-stream-check chunk-movement-check
make DOOM_MAP=E1M1 BUILDDIR=build/ripdoom-e1m1 ripdoom-map ripdoom-check
make DOOM_MAP=E1M1 BUILDDIR=build/ripdoom-e1m1 ripdoom-runtime-check
make DOOM_MAP=E1M1 DOOM_SIMPLE_MAP=1 DOOM_RIPDOOM_RENDER=1 BUILDDIR=build/ripdoom-render-e1m1 ROM=build/ripdoom-render-e1m1-cart GFX_ROM_DIR=build/ripdoom-render-e1m1-assets cart
make bsp-asset-check
tools/smoke_gameplay.sh
make key-test-rom
make key-test-gngeo
make key-door-test-rom
make key-door-test-gngeo
tools/smoke_key_door.sh
make combat-test-rom
make combat-test-gngeo
tools/smoke_combat_interaction.sh
make encounter-test-rom
make encounter-test-gngeo
tools/smoke_e1m1_encounter.sh
make exit-test-rom
make exit-test-gngeo
tools/smoke_e1m1_exit.sh
tools/smoke_enemy_visibility.sh
make monster-gallery-rom
make monster-gallery-gngeo
make arsenal-test-rom
make arsenal-test-gngeo
make death-test-rom
make death-test-gngeo
tools/smoke_death_drop.sh
make powerup-test-rom
make powerup-test-gngeo
tools/smoke_powerup.sh
tools/stress_movement.sh
tools/bench_movement.sh
make DOOM_MAP=E1M2
make DOOM_IWAD=/path/to/DOOM.WAD DOOM_MAP=E1M1
make DOOM_MAP=E1M1 DOOM_MAP_WIDTH=38 DOOM_MAP_HEIGHT=27
make DOOM_MAP=E1M1 DOOM_SKILL_MASK=2
python3 tools/doomgeo_build.py pages --out dist/pages
make smoke-screenshot
DOOM_MAP=E1M1 tools/capture_compare.sh
COMPARE_WAYPOINT=e1m1-scout tools/capture_compare.sh
COMPARE_WAYPOINT=e1m2-start tools/capture_compare.sh
python3 tools/inspect_map_specials.py --map E1M2You must provide your own Neo Geo BIOS for local emulation. The browser package
uses a separate Freedoom-based ROM and an FBNeo-compatible packaging path. The
browser player launches a magdrop2 romset package internally so the arcade
core accepts the generated DoomGeo homebrew ROM zip.
- Feature Inventory
- Architecture Notes
- Roadmap
- Reference Port Notes
- Build and Packaging
- Release Plan
- Video Reference Transcript
- Neo Geo Playability Patch Notes
Special thanks to Dimitris Giannakis, MVG / Modern Vintage Gamer, for the Neo Geo Doom/raycasting video reference that motivated the sprite-strip direction: https://www.youtube.com/watch?v=4f1-7c6WX10
These projects are useful references, but code is not copied into this branch:
- SNES Doom / DOOM-FX is the closest low-power console Doom reference for map packaging, preprocessed render data, and the tradeoffs around leaving floors/ceilings simpler than PC Doom.
- doomgeneric shows a compact platform API around Doom's tick/frame/input model.
- PureDOOM shows a single-header, callback-oriented Doom source packaging style and a clear license section.
- id Software DOOM is the historical source release used for license and architecture context.
Any future code import from these projects must be deliberate, attributed, and license-compatible. Current work adapts ideas and terminology only.
DoomGeo is research/homebrew work derived from this repo's Neo Geo raycaster
code plus original conversion/runtime code written here. It does not include a
commercial Doom IWAD, a Neo Geo BIOS, or proprietary id Software game data. The
default build downloads shareware/Freedoom-compatible WAD data under .tools/
for local conversion.
The official id Software DOOM source release is distributed under GPL-2.0. The historical DOOM Source Code License text, included below because several Doom ports keep it visible for provenance, is not a grant for commercial Doom asset redistribution.
Historical DOOM Source Code License text
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Built against ngdevkit. Hardware details were cross-referenced with the Neo Geo Development Wiki.