1 files changed, 670 insertions, 0 deletions
diff --git a/home/map_objects.asm b/home/map_objects.asm
new file mode 100644
index 00000000..f4a4d6d5
--- /dev/null
+++ b/home/map_objects.asm
@@ -0,0 +1,670 @@
+; Functions handling map objects.
+
+GetSpritePalette:: ; 17ff
+	push hl
+	push de
+	push bc
+	ld c, a
+
+	callba _GetSpritePalette
+
+	ld a, c
+	pop bc
+	pop de
+	pop hl
+	ret
+; 180e
+
+GetSpriteVTile:: ; 180e
+	push hl
+	push bc
+	ld hl, UsedSprites + 2
+	ld c, SPRITE_GFX_LIST_CAPACITY - 1
+	ld b, a
+	ld a, [hMapObjectIndexBuffer]
+	cp 0
+	jr z, .nope
+	ld a, b
+.loop
+	cp [hl]
+	jr z, .found
+rept 2
+	inc hl
+endr
+	dec c
+	jr nz, .loop
+	ld a, [UsedSprites + 1]
+	scf
+	jr .done
+
+.nope
+	ld a, [UsedSprites + 1]
+	jr .done
+
+.found
+	inc hl
+	xor a
+	ld a, [hl]
+
+.done
+	pop bc
+	pop hl
+	ret
+; 1836
+
+DoesSpriteHaveFacings:: ; 1836
+	push de
+	push hl
+
+	ld b, a
+	ld a, [hROMBank]
+	push af
+	ld a, BANK(_DoesSpriteHaveFacings)
+	rst Bankswitch
+
+	ld a, b
+	call _DoesSpriteHaveFacings
+	ld c, a
+
+	pop de
+	ld a, d
+	rst Bankswitch
+
+	pop hl
+	pop de
+	ret
+; 184a
+
+GetPlayerStandingTile:: ; 184a
+	ld a, [PlayerStandingTile]
+	call GetTileCollision
+	ld b, a
+	ret
+; 1852
+
+CheckOnWater:: ; 1852
+	ld a, [PlayerStandingTile]
+	call GetTileCollision
+	sub 1
+	ret z
+	and a
+	ret
+; 185d
+
+GetTileCollision:: ; 185d
+; Get the collision type of tile a.
+
+	push de
+	push hl
+
+	ld hl, TileCollisionTable
+	ld e, a
+	ld d, 0
+	add hl, de
+
+	ld a, [hROMBank]
+	push af
+	ld a, BANK(TileCollisionTable)
+	rst Bankswitch
+	ld e, [hl]
+	pop af
+	rst Bankswitch
+
+	ld a, e
+	and $f ; lo nybble only
+
+	pop hl
+	pop de
+	ret
+; 1875
+
+CheckGrassTile:: ; 1875
+	ld d, a
+	and $f0
+	cp $10
+	jr z, .ok_10
+	cp $20
+	jr z, .ok_20
+	scf
+	ret
+
+.ok_10
+	ld a, d
+	and 7
+	ret z
+	scf
+	ret
+; For some reason, the above code is duplicated down here.
+.ok_20
+	ld a, d
+	and 7
+	ret z
+	scf
+	ret
+; 188e
+
+CheckSuperTallGrassTile:: ; 188e
+	cp $14
+	ret z
+	cp $1c
+	ret
+; 1894
+
+CheckCutTreeTile:: ; 1894
+	cp $12
+	ret z
+	cp $1a
+	ret
+; 189a
+
+CheckHeadbuttTreeTile:: ; 189a
+	cp $15
+	ret z
+	cp $1d
+	ret
+; 18a0
+
+CheckCounterTile:: ; 18a0
+	cp $90
+	ret z
+	cp $98
+	ret
+; 18a6
+
+CheckPitTile:: ; 18a6
+	cp $60
+	ret z
+	cp $68
+	ret
+; 18ac
+
+CheckIceTile:: ; 18ac
+	cp $23
+	ret z
+	cp $2b
+	ret z
+	scf
+	ret
+; 18b4
+
+CheckWhirlpoolTile:: ; 18b4
+	nop
+	cp $24
+	ret z
+	cp $2c
+	ret z
+	scf
+	ret
+; 18bd
+
+CheckWaterfallTile:: ; 18bd
+	cp $33
+	ret z
+	cp $3b
+	ret
+; 18c3
+
+CheckStandingOnEntrance:: ; 18c3
+	ld a, [PlayerStandingTile]
+	cp $71 ; door
+	ret z
+	cp $79
+	ret z
+	cp $7a ; stairs
+	ret z
+	cp $7b ; cave
+	ret
+; 18d2
+
+GetMapObject:: ; 18d2
+; Return the location of map object a in bc.
+	ld hl, MapObjects
+	ld bc, OBJECT_LENGTH
+	call AddNTimes
+	ld b, h
+	ld c, l
+	ret
+; 18de
+
+CheckObjectVisibility:: ; 18de
+; Sets carry if the object is not visible on the screen.
+	ld [hMapObjectIndexBuffer], a
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	jr z, .not_visible
+	ld [hObjectStructIndexBuffer], a
+	call GetObjectStruct
+	and a
+	ret
+
+.not_visible
+	scf
+	ret
+; 18f5
+
+CheckObjectTime:: ; 18f5
+	ld hl, MAPOBJECT_HOUR
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	jr nz, .check_hour
+	ld hl, MAPOBJECT_TIMEOFDAY
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	jr z, .timeofday_always
+	ld hl, .TimeOfDayValues_191e
+	ld a, [TimeOfDay]
+	add l
+	ld l, a
+	jr nc, .ok
+	inc h
+
+.ok
+	ld a, [hl]
+	ld hl, MAPOBJECT_TIMEOFDAY
+	add hl, bc
+	and [hl]
+	jr nz, .timeofday_always
+	scf
+	ret
+
+.timeofday_always
+	and a
+	ret
+
+.TimeOfDayValues_191e
+	db 1 << MORN ; 1
+	db 1 << DAY  ; 2
+	db 1 << NITE ; 4
+
+.check_hour
+	ld hl, MAPOBJECT_HOUR
+	add hl, bc
+	ld d, [hl]
+	ld hl, MAPOBJECT_TIMEOFDAY
+	add hl, bc
+	ld e, [hl]
+	ld hl, hHours
+	ld a, d
+	cp e
+	jr z, .yes
+	jr c, .check_timeofday
+	ld a, [hl]
+	cp d
+	jr nc, .yes
+	cp e
+	jr c, .yes
+	jr z, .yes
+	jr .no
+
+.check_timeofday
+	ld a, e
+	cp [hl]
+	jr c, .no
+	ld a, [hl]
+	cp d
+	jr nc, .yes
+	jr .no
+
+.yes
+	and a
+	ret
+
+.no
+	scf
+	ret
+; 194d
+
+; XXX
+	ld [hMapObjectIndexBuffer], a
+	call GetMapObject
+	call CopyObjectStruct
+	ret
+; 1956
+
+_CopyObjectStruct:: ; 1956
+	ld [hMapObjectIndexBuffer], a
+	call UnmaskObject
+	ld a, [hMapObjectIndexBuffer]
+	call GetMapObject
+	callba CopyObjectStruct
+	ret
+; 1967
+
+ApplyDeletionToMapObject:: ; 1967
+	ld [hMapObjectIndexBuffer], a
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	ret z ; already hidden
+	ld [hl], -1
+	push af
+	call .CheckStopFollow
+	pop af
+	call GetObjectStruct
+	callba DeleteMapObject
+	ret
+
+.CheckStopFollow
+	ld hl, wObjectFollow_Leader
+	cp [hl]
+	jr z, .ok
+	ld hl, wObjectFollow_Follower
+	cp [hl]
+	ret nz
+.ok
+	callba StopFollow
+	ld a, -1
+	ld [wObjectFollow_Leader], a
+	ld [wObjectFollow_Follower], a
+	ret
+; 199f
+
+DeleteObjectStruct:: ; 199f
+	call ApplyDeletionToMapObject
+	call MaskObject
+	ret
+; 19a6
+
+CopyPlayerObjectTemplate:: ; 19a6
+	push hl
+	call GetMapObject
+	ld d, b
+	ld e, c
+	ld a, -1
+	ld [de], a
+	inc de
+	pop hl
+	ld bc, OBJECT_LENGTH - 1
+	call CopyBytes
+	ret
+; 19b8
+
+; XXX
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	push af
+	ld [hl], -1
+	inc hl
+	ld bc, OBJECT_LENGTH - 1
+	xor a
+	call ByteFill
+	pop af
+	cp -1
+	ret z
+	cp $d
+	ret nc
+	ld b, a
+	ld a, [wObjectFollow_Leader]
+	cp b
+	jr nz, .ok
+	ld a, -1
+	ld [wObjectFollow_Leader], a
+
+.ok
+	ld a, b
+	call GetObjectStruct
+	callba DeleteMapObject
+	ret
+; 19e9
+
+LoadMovementDataPointer:: ; 19e9
+; Load the movement data pointer for person a.
+	ld [wMovementPerson], a
+	ld a, [hROMBank]
+	ld [wMovementDataPointer], a
+	ld a, l
+	ld [wMovementDataPointer + 1], a
+	ld a, h
+	ld [wMovementDataPointer + 2], a
+	ld a, [wMovementPerson]
+	call CheckObjectVisibility
+	ret c
+
+	ld hl, OBJECT_MOVEMENTTYPE
+	add hl, bc
+	ld [hl], SPRITEMOVEDATA_SCRIPTED
+
+	ld hl, OBJECT_STEP_TYPE
+	add hl, bc
+	ld [hl], STEP_TYPE_00
+
+	ld hl, VramState
+	set 7, [hl]
+	and a
+	ret
+; 1a13
+
+FindFirstEmptyObjectStruct:: ; 1a13
+; Returns the index of the first empty object struct in A and its address in HL, then sets carry.
+; If all object structs are occupied, A = 0 and Z is set.
+; Preserves BC and DE.
+	push bc
+	push de
+	ld hl, ObjectStructs
+	ld de, OBJECT_STRUCT_LENGTH
+	ld c, NUM_OBJECT_STRUCTS
+.loop
+	ld a, [hl]
+	and a
+	jr z, .break
+	add hl, de
+	dec c
+	jr nz, .loop
+	xor a
+	jr .done
+
+.break
+	ld a, NUM_OBJECT_STRUCTS
+	sub c
+	scf
+
+.done
+	pop de
+	pop bc
+	ret
+; 1a2f
+
+GetSpriteMovementFunction:: ; 1a2f
+	ld hl, OBJECT_MOVEMENTTYPE
+	add hl, bc
+	ld a, [hl]
+	cp NUM_SPRITEMOVEDATA
+	jr c, .ok
+	xor a
+
+.ok
+	ld hl, SpriteMovementData
+	ld e, a
+	ld d, 0
+rept SPRITEMOVEDATA_FIELDS
+	add hl,de
+endr
+	ld a, [hl]
+	ret
+; 1a47
+
+GetInitialFacing:: ; 1a47
+	push bc
+	push de
+	ld e, a
+	ld d, 0
+	ld hl, SpriteMovementData + 1 ; init facing
+rept SPRITEMOVEDATA_FIELDS
+	add hl,de
+endr
+	ld a, BANK(SpriteMovementData)
+	call GetFarByte
+rept 2
+	add a
+endr
+	and $c
+	pop de
+	pop bc
+	ret
+; 1a61
+
+CopySpriteMovementData:: ; 1a61
+	ld l, a
+	ld a, [hROMBank]
+	push af
+	ld a, BANK(SpriteMovementData)
+	rst Bankswitch
+	ld a, l
+	push bc
+
+	call .CopyData
+
+	pop bc
+	pop af
+	rst Bankswitch
+
+	ret
+; 1a71
+
+.CopyData ; 1a71
+	ld hl, OBJECT_MOVEMENTTYPE
+	add hl, de
+	ld [hl], a
+
+	push de
+	ld e, a
+	ld d, 0
+	ld hl, SpriteMovementData + 1 ; init facing
+rept SPRITEMOVEDATA_FIELDS
+	add hl, de
+endr
+	ld b, h
+	ld c, l
+	pop de
+
+	ld a, [bc]
+	inc bc
+	rlca
+	rlca
+	and %00001100
+	ld hl, OBJECT_FACING
+	add hl, de
+	ld [hl], a
+
+	ld a, [bc]
+	inc bc
+	ld hl, OBJECT_ACTION
+	add hl, de
+	ld [hl], a
+
+	ld a, [bc]
+	inc bc
+	ld hl, OBJECT_FLAGS1
+	add hl, de
+	ld [hl], a
+
+	ld a, [bc]
+	inc bc
+	ld hl, OBJECT_FLAGS2
+	add hl, de
+	ld [hl], a
+
+	ld a, [bc]
+	inc bc
+	ld hl, OBJECT_PALETTE
+	add hl, de
+	ld [hl], a
+	ret
+; 1aae
+
+_GetMovementByte:: ; 1aae
+; Switch to the movement data bank
+	ld a, [hROMBank]
+	push af
+	ld a, [hli]
+	rst Bankswitch
+; Load the current script byte as given by OBJECT_MOVEMENT_BYTE_INDEX, and increment OBJECT_MOVEMENT_BYTE_INDEX
+	ld a, [hli]
+	ld d, [hl]
+	ld hl, OBJECT_MOVEMENT_BYTE_INDEX
+	add hl, bc
+	add [hl]
+	ld e, a
+	ld a, d
+	adc 0
+	ld d, a
+	inc [hl]
+	ld a, [de]
+	ld h, a
+	pop af
+	rst Bankswitch
+
+	ld a, h
+	ret
+; 1ac6
+
+SetVramState_Bit0:: ; 1ac6
+	ld hl, VramState
+	set 0, [hl]
+	ret
+; 1acc
+
+ResetVramState_Bit0:: ; 1acc
+	ld hl, VramState
+	res 0, [hl]
+	ret
+; 1ad2
+
+UpdateSprites:: ; 1ad2
+	ld a, [VramState]
+	bit 0, a
+	ret z
+
+	callba Function55e0
+	callba _UpdateSprites
+	ret
+; 1ae5
+
+GetObjectStruct:: ; 1ae5
+	ld bc, OBJECT_STRUCT_LENGTH
+	ld hl, ObjectStructs
+	call AddNTimes
+	ld b, h
+	ld c, l
+	ret
+; 1af1
+
+GetObjectSprite:: ; 1af1
+	ld hl, OBJECT_SPRITE
+	add hl, bc
+	ld a, [hl]
+	and a
+	ret
+; 1af8
+
+SetSpriteDirection:: ; 1af8
+	; preserves other flags
+	push af
+	ld hl, OBJECT_FACING
+	add hl, bc
+	ld a, [hl]
+	and %11110011
+	ld e, a
+	pop af
+	and %00001100
+	or e
+	ld [hl], a
+	ret
+; 1b07
+
+GetSpriteDirection:: ; 1b07
+	ld hl, OBJECT_FACING
+	add hl, bc
+	ld a, [hl]
+	and %00001100
+	ret
+; 1b0f