# Native port status and reference checks

## Reproducible reference

The private `.reference/pokecrystal` checkout is pinned to `7a7881d0d62e0ddbd82dcf10e7116807487ac651`. With RGBDS 1.0.3, its `crystal11` build is byte-identical to the supplied English US/Europe revision 1.1 ROM. `npm run check:reference` verifies the files and commit. It checks every ROM and RAM address in `src/game/rom/profile.ts` against generated symbols, event constants against `constants/event_flags.asm`, and map-group bounds against `data/maps/maps.asm`.

To recreate the private reference:

```sh
git clone https://github.com/pret/pokecrystal.git .reference/pokecrystal
git -C .reference/pokecrystal checkout 7a7881d0d62e0ddbd82dcf10e7116807487ac651
make -C .reference/pokecrystal crystal11 -j4
npm run check:reference
```

Install RGBDS 1.0.3 separately. No script downloads a game ROM. `CRYSTAL_ROM_PATH` optionally selects another local location; checks otherwise use `Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc` at the root.

The reference checkout, rebuilt ROM, extracted graphics, saves and gameplay screenshots must stay local and ignored. The shipping profile contains addresses and format constants, not game content.

## Routine map

These paths refer to the pinned [PRET source](https://github.com/pret/pokecrystal/tree/7a7881d0d62e0ddbd82dcf10e7116807487ac651).

| Native module                    | PRET reference                                                                                                                 | Evidence and limits                                                                                                                                                                                                                     |
| -------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `game/rom/lz.ts`                 | `home/decompress.asm`                                                                                                          | All LZ command types have unit vectors; six tilesets match original ASM execution byte-for-byte.                                                                                                                                        |
| `game/rom/assets.ts` maps/events | `data/maps/maps.asm`, `data/maps/attributes.asm`, `data/maps/scenes.asm`, `data/maps/landmarks.asm`, `macros/scripts/maps.asm` | Any map header in the ROM's 26 groups decodes; only the six ported maps can be entered. Location names, scene-variable owners and connection offsets come from the ROM.                                                                 |
| Tiles/palettes                   | `home/map.asm`, `engine/gfx/color.asm`, `engine/tilesets/mapgroup_roofs.asm`                                                   | Graphics match rebuilt reference bytes. Connected maps draw beyond the edges with the current tileset, like the original strips. Terrain animation and other special palettes pending.                                                  |
| Sprites/rendering                | `data/sprites/sprites.asm`, `data/sprites/facings.asm`, `data/sprites/emotes.asm`                                              | Chris/Kris, standard NPCs, emote bubbles and jump shadows decoded. Walking frames follow `SetFacingStepAction`. Dynamic Pokémon icons and room decorations pending.                                                                     |
| `game/world/world.ts`            | `engine/overworld/events.asm`, `player_movement.asm`, `warp_connection.asm`, `data/collision/collision_permissions.asm`        | 30 Hz overworld ticks, 8-tick walks, 16-tick ledge jumps, directional mats, animated door/stair exits, connection coordinates, events, scenes and callbacks. NPC random walks and spins follow `HandleNPCStep`. Surfing remains absent; turn timing still needs comparison. |
| Event interpreter                | `macros/scripts/events.asm`, `engine/overworld/scripting.asm`, `engine/events/std_scripts.asm`                                 | Resumable; yields text, choices, movement, emotes and pauses. Scenes, phone contacts, string buffers and object commands. Unknown commands and specials abort without committing.                                                       |
| Movement interpreter             | `macros/scripts/movement.asm`, `engine/overworld/movement.asm`, `engine/overworld/map_objects.asm`                             | Turns, steps, slides, jumps (two tiles with the original arc), sleeps, facing locks, visibility and emotes. `follow` moves the follower into the leader's previous square.                                                              |
| Specials                         | `data/events/special_pointers.asm`, `engine/rtc/timeset.asm`, `engine/overworld/decorations.asm`                               | Selected by routine address from the ROM table: `SetDayOfWeek`, initial DST flags, `RestartMapMusic` (no audio yet), the empty-room decoration toggles, `HealParty`, `HealMachineAnim` (presentation only), `CheckPokerus` and the `StubbedTrainerRankings_Healings` stub.                                                                              |
| `game/rom/pokemon.ts`            | `data/pokemon/base_stats`, `evos_attacks.asm`, `data/moves/moves.asm`, `data/items/attributes.asm`, `engine/gfx/load_pics.asm` | Species, move and item names, base data, learnsets, move PP, item pockets, growth-rate exp and front pictures (`FixPicBank`, `PadFrontpic`). Starter pictures match rebuilt bytes.                                                      |
| `game/party`                     | `engine/pokemon/move_mon.asm`, `engine/pokemon/caught_data.asm`, `engine/items/items.asm`                                      | `GeneratePartyMonStats` for script gifts: DVs, `FillMoves`, PP, exp, `CalcMonStatC`, happiness and caught data. `PutItemInPocket`, key items and `TossItem`. PC boxes, TMs and HMs are refused.                                         |
| Text interpreter                 | `macros/scripts/text.asm`, `constants/charmap.asm`, `home/text.asm`                                                            | Literal/far text, RAM names and string buffers from native state, numbers of dots, and sound or pause cues (consumed). `text_asm` and other RAM reads are refused.                                                                      |

Supported event opcodes are explicit in the interpreter switch. Audio commands consume their operands, but sound sequencing is pending; those opcodes do not imply complete audiovisual behavior. `pause` holds the current text or waits the original number of overworld ticks.

Scripts run on a private draft. The world presents each yielded effect, then resumes the script with the player's answer or when the animation ends. The draft is committed only when the script ends. A save made during a scene returns the committed state, and coordinate events rewind to the source of the triggering walk or two-tile jump. Saves during movement also retain the source tile until arrival events run, including across map connections. A failed scene restores the positions it had changed. As in `LoadMapObjects`, map objects spawn when the map loads. Later flag changes do not remove objects already shown; only `appear` and `disappear` do.

The opening scenes currently run end to end from the ROM: Mom's Pokégear, weekday and DST scene, the teacher at the west edge, the rival at the lab window, Elm's introduction with its yes/no loop, the lab's exit guard, the starter choice with `pokepic`, `givepoke` and the nickname prompt, Elm's directions and the aide's Potion through the ROM's own `GiveItemScript`. `callasm` accepts only explicitly empty routines or native translations: `HalveMoney`, `GetWhiteoutSpawn`, the item ball's `TryReceiveItem` and the fruit tree routines. The naming screen is a native text field limited to the characters the original offers.

## Actual emulator comparison

`tests/reference-parity.spec.ts` loads the user's ROM into the reference emulator and places a small original test trampoline in emulated WRAM. It calls the ROM's `FarDecompress` routine at `$0b40`, then sets a return sentinel. Every output byte is compared with the native decoder for six supported map tilesets. This executes the original routine rather than comparing two copies of our code.

The same suite compares 400 damage cases and 400 type-effectiveness cases per browser against the original battle routines. Battle unit tests cover win, escape, loss, experience, level-up and move-learning flows. This establishes parity only for the compared routines and inputs. It does not prove complete gameplay, rendering, battles, audio, timing or physical-device parity. Extend controlled comparisons as each subsystem is translated.

## Validation

```sh
npm test
npm run test:e2e
npm run check:reference
npm run check:vendor
npm run build
npm run check:release
npm run build:reference
```

User-ROM tests skip when the file is absent, including public CI. Synthetic tests still run. Comparing with rebuilt graphics also needs the private PRET build. Do not report skipped private checks as CI passes.

Native production is `dist/`; the optional reference output is `dist-reference/`. Release checks reject emulator dependencies, binary game files and embedded binary assets in the native output. Source review is still required when adding assets or data.

## Save schema

Native saves are version 3. Version 2 added scene values by owning map, phone contacts, the weekday offset and DST flag, and positions of objects that scripts moved on the current map. Version 3 adds the player ID, party, bag, Pokédex seen/caught sets and money. Early version-3 backups without money receive the original starting balance; explicitly invalid balances are rejected. Restores recompute each Pokémon's stats from its DVs and reject any mismatch, and check every item against its ROM pocket. Older saves migrate with new-game defaults; a missing player ID is drawn as a new game draws it. Objects are restored from the save on continue, and only the TILES callback runs, as in `MapSetupScript_Continue`.

## Next slice

Route 29 and Cherrygrove are enabled with item balls, fruit trees and the daily reset, the Pokémon Center nurse and the recorded whiteout spawn. NPCs roam. Next: trainer sight lines and trainer battles, capture with the catching tutorial, and party, bag and Pokégear menus over the native models. Other specials stay refused until translated.