Hooks State Queries Rooms - drizztdourden08/relic-of-the-past GitHub Wiki

State Queries for Rooms & Collision

Collision grids, room geometry, doors, stairs, and dungeon-map placement: the data the navigation engine consumes. All return HEAPU8 pointers.

Sources: state_queries.c, state_queries_grids.c, state_queries_rooms.c, state_queries_room_exits.c Bridge: lib/game/bridge/room-grids.ts, room-layout.ts, room-doors.ts

Collision attributes

WasmGetIndoorAttrTable

int WasmGetIndoorAttrTable(void) β†’ pointer to dung_bg2_attr_table (8 KB). 0x0000-0x0FFF = upper-layer attrs, 0x1000-0x1FFF = lower-layer attrs (64Γ—64 tiles per layer).

WasmGetLinkIsOnLowerLevel

int WasmGetLinkIsOnLowerLevel(void) β†’ 1 if Link is on the lower layer, else 0.

WasmGetRoomCollisionType

int WasmGetRoomCollisionType(void) β†’ current room's collision type (dung_hdr_collision), or -1 if outdoors.

WasmGetRoomCollisionTypeForRoom

int WasmGetRoomCollisionTypeForRoom(int room_id) β†’ collision type (hdr[0] >> 2) & 7 read straight from the ROM header for any room id (0-0x127); headless-safe. Returns -1 if out of range.

WasmBuildOverworldAttrGrid

int WasmBuildOverworldAttrGrid(int screen_idx) β†’ builds a 64Γ—64 collision-attr grid for an overworld screen on demand and returns its pointer (row stride 64). Decodes Map16β†’Map8β†’attr and propagates the deep-grass/water priority bit.

WasmBuildRoomAttrGrid

int WasmBuildRoomAttrGrid(int room_id) β†’ loads room_id into the dungeon tilemap, rebuilds the collision attr table and returns a pointer to a private copy of it (read 64Γ—64, +0x1000 for the lower layer). This is heavy: it runs the real room loader, so call it off the hot path.

It snapshots and restores all of WRAM around the rebuild, so it leaves the running game untouched. It still answers from room data, not live state. For the room the player currently occupies use WasmGetIndoorAttrTable, which reports the runtime collision the player is actually walking on (opened doorways, lifted pots, pushed blocks).

WasmGetToggleFloorPositions

int WasmGetToggleFloorPositions(void) β†’ the toggle-floor positions captured by the last WasmBuildRoomAttrGrid call: [count, pad] then up to 16 Γ— [posLo, posHi, row, col].

Room geometry

WasmGetRoomLayoutInfo

int WasmGetRoomLayoutInfo(void) β†’ 8-byte buffer (zeroed if outdoors):

Off Field Off Field
0 layout index 0-7 3 Link quadrant X (0/1)
1 quadrant fullsize X (0=normal, 2=merged) 4 Link quadrant Y (0/2)
2 quadrant fullsize Y 5-7 pad

WasmGetDungeonMapPosition

int WasmGetDungeonMapPosition(void) β†’ 12-byte buffer giving the room's footprint in the 5Γ—5 dungeon map grid (zeroed for caves/houses):

Off Field Off Field
0 map col 5 found (0/1)
1 map row 6 effective width (cells)
2 current floor 7 effective height (cells)
3 # above-ground floors 8 origin col (= map col)
4 # basement floors 9 origin row (= map row)

WasmGetRoomDoorBoundaryTiles

int WasmGetRoomDoorBoundaryTiles(void) β†’ [count, pad] then up to 16 Γ— 5 bytes: [direction, tileCol, tileRow, doorType, isOpen]. direction 0=N 1=S 2=W 3=E. For N/S doors tileCol is the leftmost of the 4-tile opening; for W/E, tileRow is the topmost.

Exits, stairs & inter-room links

WasmGetRoomExitDoors

int WasmGetRoomExitDoors(void) β†’ [count, pad] then up to 8 Γ— [tileCol, tileRow, direction] (exit-to-overworld doors + entrance-type doors). Empty if outdoors.

WasmGetRoomStairInfo

int WasmGetRoomStairInfo(void) β†’ [count, pad] then up to 4 Γ— [destRoom, tileRow, tileCol, direction]. direction: 0=up, 4=down (attr bit 2). Found by scanning attr tiles 0x30-0x37 (low 2 bits = stair index).

WasmGetRoomTravelDestinations

int WasmGetRoomTravelDestinations(void) β†’ 5 bytes from the room header: [0]=pit/block destination, [1..4]=stair destinations for stair indices 0-3. Zeroed if outdoors.

WasmGetStaircaseType

int WasmGetStaircaseType(void) β†’ kind_of_in_room_staircase: 0=intra-room stairs (layer change + room shift), 1=layer stairs, 2=pseudo/water/none (layer changes are blocked). -1 if outdoors.

WasmGetRoomWalkBoundaries

int WasmGetRoomWalkBoundaries(void) → [count, pad] then up to 4 × [destRoomLo, destRoomHi, tileRow, tileCol]: palace toggle-door passages where walking through switches rooms (e.g. Castle→Sewer). Destination is inferred from the edge the toggle sits on.