Game Remake

Game Remake

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Faithful C++ reimplementation of Might & Magic II (Amiga), driven by the 68k disassembly and decoded .dat / asset formats in EXTRACTED/.

Design principle

• 100% ASM/Amiga fidelity — match original 68k behaviour exactly; no invented UX. See Game remake (game/) in CLAUDE.md.

Targets

Platform	Backend	C/C++ runtime
Windows, Linux, macOS	SDL2	Host libc + libstdc++
Amiga (68000+)	ACE (AmigaPorts/ACE)	mini-std + custom new/delete/operator[] — no libstdc++

Desktop builds use SDL2 directly (not ACE’s experimental SDL shim). Amiga builds link ACE for blitter/copper/input/audio and route all dynamic allocation through mm2::runtime (memAlloc / memFree).

Layout

game/
  CMakeLists.txt
  include/mm2/          Shared headers (platform-neutral game API)
  src/
    main.cpp            Entry (desktop) or thin wrapper (Amiga + ACE generic main)
    Game.cpp            High-level setup / tick / draw
    TitleScreen.cpp     Title attract/menu (320×200), logo, peekers
    ui/                 Character UI backends (AmigaClassic / Stub)
    gfx/                320×200 compositor + Mm2Font8x8.inc
    platform/sdl/       SDL2 window, input, file I/O
    platform/amiga/     ACE viewport, chip/fast mem, OS file hooks
    runtime/            Allocators, freestanding buffers
EXTRACTED/decomp/       Pure-C codecs lifted from RE (shared with editor tools)

Architecture

flowchart TB
  subgraph host [Host layer]
    SDL[SDL2 PC/Linux]
    ACE[ACE Amiga]
  end
  subgraph plat [mm2::platform]
    IO[File I/O]
    IN[Input]
    VID[Present / blit]
    CLK[Timer]
  end
  subgraph core [Game core — portable C++]
    GS[GameState A4 workspace]
    MAP[map.dat + 3D view]
    EVT[event VM 0x172CA]
    CBT[combat 0x12A22]
    SVC[town services]
  end
  subgraph data [Data layer — C codecs]
    DAT[.dat loaders]
    GFX[.32 / .anm codecs]
    STR[str.dat]
  end
  SDL --> plat
  ACE --> plat
  plat --> core
  core --> data

Loading

Implementation phases

1. Bootstrap (current) — 320×200 compositor (ScreenCompositor), title screen (intro.32 @ (3,0) + introclips.32 pegasus/peekers + nwcp.32 logo + book.32 menu on black), roster viewer (roster.dat), 2× SDL present. Menu text uses Mm2Font8x8.inc (plain ASCII). Title animation spec: EXTRACTED/docs/39-title-screen-animation.md. Character UI is pluggable — see 39-character-ui-view-create.md.
2. Data + state — wire all .dat codecs; materialize A4 workspace (mm2_gamestate.h).
3. 3D view — port 0x2900 hood renderer (208×120 viewport, wall fields from map page 0).
4. Main loop — 0x1280 mode dispatch (overland, town, combat, menus).
5. Events — triplet scanner 0x175E2, script VM, OP_0E town-service dispatch.
6. Combat — round loop, player bar, monster AI, rewards.
7. Audio — Paula tone path from master.32 or MOD export fallback on desktop.
8. Copy protection — externalize globe/disk strings (already extracted to EXTRACTED/embedded_strings.json).

RE references: EXTRACTED/docs/README.md, EXTRACTED/mm2.capstone.annotated.asm, per-location events in EXTRACTED/docs/events/.

Build (desktop / SDL2)

Requires CMake ≥ 3.16, C++17, network on first configure (SDL2 fetched via FetchContent).

cd game
cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build
./build/mm2 ../          # pass MM2 data directory (contains map.dat, town.32, …)
./build/mm2 ../ --ui=stub   # text-only character UI fallback

Character UI plugin

View Party (P) and Create (C) use a swappable layer (game/include/mm2/ui/):

Backend	Select
AmigaClassic (default)	--ui=classic, MM2_UI=classic, or -DMM2_UI=classic
Stub (text overlay)	--ui=stub, MM2_UI=stub, or -DMM2_UI=stub

Requires book.32 in the data directory for the classic sheet backdrop. See EXTRACTED/docs/39-character-ui-view-create.md.

Validate .32 decode (C codec vs Python reference):

cmake --build build
python ../tools/test_image32_golden.py --data-dir ..

Build (Amiga / ACE)

Cross-compile with AmigaCMakeCrossToolchains and Bartman’s or Bebbo’s m68k GCC. ACE is pulled as a submodule/FetchContent when -DAMIGA=ON.

cmake -S . -B build-amiga -DCMAKE_TOOLCHAIN_FILE=…/m68k-amigaos.cmake -DAMIGA=ON
cmake --build build-amiga

Amiga link flags use -fno-exceptions -fno-rtti; game code must not depend on STL containers or iostreams on that target.

Conventions

• Endianness: .dat multibyte fields are little-endian on disk (see root CLAUDE.md).
• Graphics: planar 5-bp .32 / .anm image chunks — mm2_image32_codec.c.
• Naming: lifted routines keep sub_<addr>_<purpose> until fully understood.
• No Blitz3D: original 68k ASM is the source of truth for runtime behaviour.