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Upload literally everything from the pokecrystal16 expand-move-ID branch

home/16bit.asm

@@ -0,0 +1,92 @@
+MACRO ___conversion_table_homecall
+	; macro arguments: homecall type, function label
+	; all functions clobber af and hl (except for outputs) and preserve bc and de
+	; homecall types:
+	; - read: index to ID conversion (in: a = 8-bit ID; out: hl = 16-bit index)
+	; - write: ID to index conversion (in: hl = 16-bit index; out: a = 8-bit ID)
+	; - lock: ID locking (in: a = ID (or zero to unlock), l = position; out: a = preserved)
+	if strcmp("\1", "read") && strcmp("\1", "write") && strcmp("\1", "lock")
+		fail "16-bit homecall: invalid call type"
+	endc
+
+	if (strcmp("\1", "write") != 0)
+		ld h, a
+	endc
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(\2)
+	rst Bankswitch
+	if (strcmp("\1", "read") == 0)
+		ld a, h
+	endc
+	call \2
+	if (strcmp("\1", "read") != 0)
+		ld l, a
+	endc
+	pop af
+	rst Bankswitch
+	if (strcmp("\1", "read") != 0)
+		ld a, l
+	endc
+	ret
+ENDM
+
+MACRO ___conversion_table_homecall_readlocked
+	; macro argument: table name
+	; in: a = position
+	; out: a = 8-bit index; everything else preserved
+	push hl
+	add a, LOW(\1LockedEntries)
+	ld l, a
+	ldh a, [rSVBK]
+	ld h, a
+	ld a, BANK(\1LockedEntries)
+	ldh [rSVBK], a
+	ld a, h
+	ld h, HIGH(\1LockedEntries)
+	ld l, [hl]
+	ldh [rSVBK], a
+	ld a, l
+	pop hl
+	ret
+ENDM
+
+; in: a = 8-bit index
+; out: hl = 16-bit index; a clobbered
+GetPokemonIndexFromID::
+	___conversion_table_homecall read, _GetPokemonIndexFromID
+
+; in: hl = 16-bit index
+; out: a = 8-bit index, hl clobbered
+GetPokemonIDFromIndex::
+	___conversion_table_homecall write, _GetPokemonIDFromIndex
+
+; in: a = 8-bit index or zero (to clear), l = position
+; out: a = unchanged, hl = clobbered
+LockPokemonID::
+	___conversion_table_homecall lock, _LockPokemonID
+
+; in: a = position
+; out: a = 8-bit index; everything else preserved
+GetLockedPokemonID::
+	___conversion_table_homecall_readlocked wPokemonIndexTable
+
+; in: a = 8-bit index
+; out: hl = 16-bit index; a clobbered
+GetMoveIndexFromID::
+	___conversion_table_homecall read, _GetMoveIndexFromID
+
+; in: hl = 16-bit index
+; out: a = 8-bit index, hl clobbered
+GetMoveIDFromIndex::
+	___conversion_table_homecall write, _GetMoveIDFromIndex
+
+; in: a = 8-bit index or zero (to clear), l = position
+; out: a = unchanged, hl = clobbered
+LockMoveID::
+	___conversion_table_homecall lock, _LockMoveID
+
+; in: a = position
+; out: a = 8-bit index; everything else preserved
+GetLockedMoveID::
+	___conversion_table_homecall_readlocked wMoveIndexTable

home/array.asm

@@ -0,0 +1,71 @@
+IsInArray::
+; Find value a for every de bytes in array hl.
+; Return index in b and carry if found.
+
+	ld b, 0
+	ld c, a
+.loop
+	ld a, [hl]
+	cp -1
+	jr z, .NotInArray
+	cp c
+	jr z, .InArray
+	inc b
+	add hl, de
+	jr .loop
+
+.NotInArray:
+	and a
+	ret
+
+.InArray:
+	scf
+	ret
+
+IsInWordArray_NextItem:
+	add hl, de
+IsInWordArray::
+; Same as IsInArray, but for word values. The value is input in bc; index not returned.
+	ld a, [hli]
+	and [hl]
+	inc a
+	ret z
+	ld a, [hld]
+	cp b
+	jr nz, IsInWordArray_NextItem
+	ld a, [hl]
+	cp c
+	jr nz, IsInWordArray_NextItem
+	scf
+	ret
+
+SkipNames::
+; Skip a names.
+	ld bc, NAME_LENGTH
+	and a
+	ret z
+.loop
+	add hl, bc
+	dec a
+	jr nz, .loop
+	ret
+
+AddNTimes::
+; Add bc * a to hl.
+; Preserves bc
+	and a
+	ret z
+
+	push bc
+.loop
+	rra ; and a from below and above resets carry
+	jr nc, .noadd
+	add hl, bc
+.noadd
+	sla c
+	rl b
+	and a
+	jr nz, .loop
+.done
+	pop bc
+	ret

home/audio.asm

@@ -0,0 +1,517 @@
+; Audio interfaces.
+
+InitSound::
+	push hl
+	push de
+	push bc
+	push af
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_InitSound)
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	call _InitSound
+
+	pop af
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+UpdateSound::
+	push hl
+	push de
+	push bc
+	push af
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_UpdateSound)
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	call _UpdateSound
+
+	pop af
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+_LoadMusicByte::
+; [wCurMusicByte] = [a:de]
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	ld a, [de]
+	ld [wCurMusicByte], a
+	ld a, BANK(LoadMusicByte)
+
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+	ret
+
+PlayMusic::
+; Play music de.
+
+	push hl
+	push de
+	push bc
+	push af
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_PlayMusic) ; aka BANK(_InitSound)
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	ld a, e
+	and a
+	jr z, .nomusic
+
+	call _PlayMusic
+	jr .end
+
+.nomusic
+	call _InitSound
+
+.end
+	pop af
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+PlayMusic2::
+; Stop playing music, then play music de.
+
+	push hl
+	push de
+	push bc
+	push af
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_PlayMusic)
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	push de
+	ld de, MUSIC_NONE
+	call _PlayMusic
+	call DelayFrame
+	pop de
+	call _PlayMusic
+
+	pop af
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+PlayCry::
+; Play cry de.
+
+	push hl
+	push de
+	push bc
+	push af
+
+	ldh a, [hROMBank]
+	push af
+
+	; Cries are stuck in one bank.
+	ld a, BANK(PokemonCries)
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	ld hl, PokemonCries
+rept MON_CRY_LENGTH
+	add hl, de
+endr
+
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+	inc hl
+
+	ld a, [hli]
+	ld [wCryPitch], a
+	ld a, [hli]
+	ld [wCryPitch + 1], a
+	ld a, [hli]
+	ld [wCryLength], a
+	ld a, [hl]
+	ld [wCryLength + 1], a
+
+	ld a, BANK(_PlayCry)
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	call _PlayCry
+
+	pop af
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+PlaySFX::
+; Play sound effect de.
+; Sound effects are ordered by priority (highest to lowest)
+
+	push hl
+	push de
+	push bc
+	push af
+
+	; Is something already playing?
+	call CheckSFX
+	jr nc, .play
+
+	; Does it have priority?
+	ld a, [wCurSFX]
+	cp e
+	jr c, .done
+
+.play
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_PlaySFX)
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+	ld a, e
+	ld [wCurSFX], a
+	call _PlaySFX
+
+	pop af
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+
+.done
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+WaitPlaySFX::
+	call WaitSFX
+	jp PlaySFX
+
+WaitSFX::
+; infinite loop until sfx is done playing
+
+	push hl
+
+.wait
+	ld hl, wChannel5Flags1
+	bit 0, [hl]
+	jr nz, .wait
+	ld hl, wChannel6Flags1
+	bit 0, [hl]
+	jr nz, .wait
+	ld hl, wChannel7Flags1
+	bit 0, [hl]
+	jr nz, .wait
+	ld hl, wChannel8Flags1
+	bit 0, [hl]
+	jr nz, .wait
+
+	pop hl
+	ret
+
+IsSFXPlaying::
+; Return carry if no sound effect is playing.
+; The inverse of CheckSFX.
+	push hl
+
+	ld hl, wChannel5Flags1
+	bit 0, [hl]
+	jr nz, .playing
+	ld hl, wChannel6Flags1
+	bit 0, [hl]
+	jr nz, .playing
+	ld hl, wChannel7Flags1
+	bit 0, [hl]
+	jr nz, .playing
+	ld hl, wChannel8Flags1
+	bit 0, [hl]
+	jr nz, .playing
+
+	pop hl
+	scf
+	ret
+
+.playing
+	pop hl
+	and a
+	ret
+
+MaxVolume::
+	ld a, MAX_VOLUME
+	ld [wVolume], a
+	ret
+
+LowVolume::
+	ld a, $33 ; 50%
+	ld [wVolume], a
+	ret
+
+MinVolume::
+	xor a
+	ld [wVolume], a
+	ret
+
+FadeOutToMusic:: ; unreferenced
+	ld a, 4
+	ld [wMusicFade], a
+	ret
+
+FadeInToMusic::
+	ld a, 4 | (1 << MUSIC_FADE_IN_F)
+	ld [wMusicFade], a
+	ret
+
+SkipMusic::
+; Skip a frames of music.
+.loop
+	and a
+	ret z
+	dec a
+	call UpdateSound
+	jr .loop
+
+FadeToMapMusic::
+	push hl
+	push de
+	push bc
+	push af
+
+	call GetMapMusic_MaybeSpecial
+	ld a, [wMapMusic]
+	cp e
+	jr z, .done
+
+	ld a, 8
+	ld [wMusicFade], a
+	ld a, e
+	ld [wMusicFadeID], a
+	ld a, d
+	ld [wMusicFadeID + 1], a
+	ld a, e
+	ld [wMapMusic], a
+
+.done
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+PlayMapMusic::
+	push hl
+	push de
+	push bc
+	push af
+
+	call GetMapMusic_MaybeSpecial
+	ld a, [wMapMusic]
+	cp e
+	jr z, .done
+
+	push de
+	ld de, MUSIC_NONE
+	call PlayMusic
+	call DelayFrame
+	pop de
+	ld a, e
+	ld [wMapMusic], a
+	call PlayMusic
+
+.done
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+PlayMapMusicBike::
+; If the player's on a bike, play the bike music instead of the map music
+	push hl
+	push de
+	push bc
+	push af
+
+	xor a
+	ld [wDontPlayMapMusicOnReload], a
+	ld de, MUSIC_BICYCLE
+	ld a, [wPlayerState]
+	cp PLAYER_BIKE
+	jr z, .play
+	call GetMapMusic_MaybeSpecial
+.play
+	push de
+	ld de, MUSIC_NONE
+	call PlayMusic
+	call DelayFrame
+	pop de
+
+	ld a, e
+	ld [wMapMusic], a
+	call PlayMusic
+
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+TryRestartMapMusic::
+	ld a, [wDontPlayMapMusicOnReload]
+	and a
+	jr z, RestartMapMusic
+	xor a
+	ld [wMapMusic], a
+	ld de, MUSIC_NONE
+	call PlayMusic
+	call DelayFrame
+	xor a
+	ld [wDontPlayMapMusicOnReload], a
+	ret
+
+RestartMapMusic::
+	push hl
+	push de
+	push bc
+	push af
+	ld de, MUSIC_NONE
+	call PlayMusic
+	call DelayFrame
+	ld a, [wMapMusic]
+	ld e, a
+	ld d, 0
+	call PlayMusic
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+SpecialMapMusic::
+	ld a, [wPlayerState]
+	cp PLAYER_SURF
+	jr z, .surf
+	cp PLAYER_SURF_PIKA
+	jr z, .surf
+
+	ld a, [wStatusFlags2]
+	bit STATUSFLAGS2_BUG_CONTEST_TIMER_F, a
+	jr nz, .contest
+
+.no
+	and a
+	ret
+
+.bike ; unreferenced
+	ld de, MUSIC_BICYCLE
+	scf
+	ret
+
+.surf
+	ld de, MUSIC_SURF
+	scf
+	ret
+
+.contest
+	ld a, [wMapGroup]
+	cp GROUP_ROUTE_35_NATIONAL_PARK_GATE
+	jr nz, .no
+	ld a, [wMapNumber]
+	cp MAP_ROUTE_35_NATIONAL_PARK_GATE
+	jr z, .ranking
+	cp MAP_ROUTE_36_NATIONAL_PARK_GATE
+	jr nz, .no
+
+.ranking
+	ld de, MUSIC_BUG_CATCHING_CONTEST_RANKING
+	scf
+	ret
+
+GetMapMusic_MaybeSpecial::
+	call SpecialMapMusic
+	ret c
+	jp GetMapMusic
+
+CheckSFX::
+; Return carry if any SFX channels are active.
+	ld a, [wChannel5Flags1]
+	bit 0, a
+	jr nz, .playing
+	ld a, [wChannel6Flags1]
+	bit 0, a
+	jr nz, .playing
+	ld a, [wChannel7Flags1]
+	bit 0, a
+	jr nz, .playing
+	ld a, [wChannel8Flags1]
+	bit 0, a
+	jr nz, .playing
+	and a
+	ret
+.playing
+	scf
+	ret
+
+TerminateExpBarSound::
+	xor a
+	ld [wChannel5Flags1], a
+	ld [wPitchSweep], a
+	ldh [rNR10], a
+	ldh [rNR11], a
+	ldh [rNR12], a
+	ldh [rNR13], a
+	ldh [rNR14], a
+	ret
+
+ChannelsOff::
+; Quickly turn off music channels
+	xor a
+	ld [wChannel1Flags1], a
+	ld [wChannel2Flags1], a
+	ld [wChannel3Flags1], a
+	ld [wChannel4Flags1], a
+	ld [wPitchSweep], a
+	ret
+
+SFXChannelsOff::
+; Quickly turn off sound effect channels
+	xor a
+	ld [wChannel5Flags1], a
+	ld [wChannel6Flags1], a
+	ld [wChannel7Flags1], a
+	ld [wChannel8Flags1], a
+	ld [wPitchSweep], a
+	ret

home/battle.asm

@@ -0,0 +1,273 @@
+GetPartyParamLocation::
+; Get the location of parameter a from wCurPartyMon in hl
+	push bc
+	ld hl, wPartyMons
+	ld c, a
+	ld b, 0
+	add hl, bc
+	ld a, [wCurPartyMon]
+	call GetPartyLocation
+	pop bc
+	ret
+
+GetPartyLocation::
+; Add the length of a PartyMon struct to hl a times.
+	ld bc, PARTYMON_STRUCT_LENGTH
+	jp AddNTimes
+
+FarSkipEvolutions::
+; Calls SkipEvolutions from another bank. It can't be a farcall because it uses hl.
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(SkipEvolutions)
+	rst Bankswitch
+	call SkipEvolutions
+	pop af
+	rst Bankswitch
+	ret
+
+UserPartyAttr::
+	push af
+	ldh a, [hBattleTurn]
+	and a
+	jr nz, .ot
+	pop af
+	jr BattlePartyAttr
+.ot
+	pop af
+	jr OTPartyAttr
+
+OpponentPartyAttr::
+	push af
+	ldh a, [hBattleTurn]
+	and a
+	jr z, .ot
+	pop af
+	jr BattlePartyAttr
+.ot
+	pop af
+	jr OTPartyAttr
+
+BattlePartyAttr::
+; Get attribute a from the party struct of the active battle mon.
+	push bc
+	ld c, a
+	ld b, 0
+	ld hl, wPartyMons
+	add hl, bc
+	ld a, [wCurBattleMon]
+	call GetPartyLocation
+	pop bc
+	ret
+
+OTPartyAttr::
+; Get attribute a from the party struct of the active enemy mon.
+	push bc
+	ld c, a
+	ld b, 0
+	ld hl, wOTPartyMon1Species
+	add hl, bc
+	ld a, [wCurOTMon]
+	call GetPartyLocation
+	pop bc
+	ret
+
+ResetDamage::
+	xor a
+	ld [wCurDamage], a
+	ld [wCurDamage + 1], a
+	ret
+
+SetPlayerTurn::
+	xor a
+	ldh [hBattleTurn], a
+	ret
+
+SetEnemyTurn::
+	ld a, 1
+	ldh [hBattleTurn], a
+	ret
+
+UpdateOpponentInParty::
+	ldh a, [hBattleTurn]
+	and a
+	jr z, UpdateEnemyMonInParty
+	jr UpdateBattleMonInParty
+
+UpdateUserInParty::
+	ldh a, [hBattleTurn]
+	and a
+	jr z, UpdateBattleMonInParty
+	jr UpdateEnemyMonInParty
+
+UpdateBattleMonInParty::
+; Update level, status, current HP
+
+	ld a, [wCurBattleMon]
+
+UpdateBattleMon::
+	ld hl, wPartyMon1Level
+	call GetPartyLocation
+
+	ld d, h
+	ld e, l
+	ld hl, wBattleMonLevel
+	ld bc, wBattleMonMaxHP - wBattleMonLevel
+	jp CopyBytes
+
+UpdateEnemyMonInParty::
+; Update level, status, current HP
+
+; No wildmons.
+	ld a, [wBattleMode]
+	dec a
+	ret z
+
+	ld a, [wCurOTMon]
+	ld hl, wOTPartyMon1Level
+	call GetPartyLocation
+
+	ld d, h
+	ld e, l
+	ld hl, wEnemyMonLevel
+	ld bc, wEnemyMonMaxHP - wEnemyMonLevel
+	jp CopyBytes
+
+RefreshBattleHuds::
+	call UpdateBattleHuds
+	ld c, 3
+	call DelayFrames
+	jp WaitBGMap
+
+UpdateBattleHuds::
+	farcall UpdatePlayerHUD
+	farcall UpdateEnemyHUD
+	ret
+
+INCLUDE "home/battle_vars.asm"
+
+FarCopyRadioText::
+	inc hl
+	ldh a, [hROMBank]
+	push af
+	ld a, [hli]
+	ld e, a
+	ld a, [hli]
+	ld d, a
+	ld a, [hli]
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+	ld a, e
+	ld l, a
+	ld a, d
+	ld h, a
+	ld de, wRadioText
+	ld bc, 2 * SCREEN_WIDTH
+	call CopyBytes
+	pop af
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+	ret
+
+MobileTextBorder::
+	; For mobile link battles only.
+	ld a, [wLinkMode]
+	cp LINK_MOBILE
+	ret c
+
+	; Draw a cell phone icon at the
+	; top right corner of the border.
+	hlcoord 19, 12
+	ld [hl], $5e ; top
+	hlcoord 19, 13
+	ld [hl], $5f ; bottom
+	ret
+
+BattleTextbox::
+; Open a textbox and print text at hl.
+	push hl
+	call SpeechTextbox
+	call MobileTextBorder
+	call UpdateSprites
+	call ApplyTilemap
+	pop hl
+	call PrintTextboxText
+	ret
+
+StdBattleTextbox::
+; Open a textbox and print battle text at 20:hl.
+
+	ldh a, [hROMBank]
+	push af
+
+	ld a, BANK(BattleText)
+	rst Bankswitch
+
+	call BattleTextbox
+
+	pop af
+	rst Bankswitch
+	ret
+
+GetBattleAnimPointer::
+	ld a, BANK(BattleAnimations)
+	rst Bankswitch
+
+	ld a, [hli]
+	ld [wBattleAnimAddress], a
+	ld a, [hl]
+	ld [wBattleAnimAddress + 1], a
+
+	; ClearBattleAnims is the only function that calls this...
+	ld a, BANK(ClearBattleAnims)
+	rst Bankswitch
+
+	ret
+
+GetBattleAnimByte::
+	push hl
+	push de
+
+	ld hl, wBattleAnimAddress
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+
+	ld a, BANK(BattleAnimations)
+	rst Bankswitch
+
+	ld a, [de]
+	ld [wBattleAnimByte], a
+	inc de
+
+	ld a, BANK(BattleAnimCommands)
+	rst Bankswitch
+
+	ld [hl], d
+	dec hl
+	ld [hl], e
+
+	pop de
+	pop hl
+
+	ld a, [wBattleAnimByte]
+	ret
+
+PushLYOverrides::
+	ldh a, [hLCDCPointer]
+	and a
+	ret z
+
+	ld a, LOW(wLYOverridesBackup)
+	ld [wRequested2bppSource], a
+	ld a, HIGH(wLYOverridesBackup)
+	ld [wRequested2bppSource + 1], a
+
+	ld a, LOW(wLYOverrides)
+	ld [wRequested2bppDest], a
+	ld a, HIGH(wLYOverrides)
+	ld [wRequested2bppDest + 1], a
+
+	ld a, (wLYOverridesEnd - wLYOverrides) / LEN_2BPP_TILE
+	ld [wRequested2bppSize], a
+	ret

home/battle_vars.asm

@@ -0,0 +1,113 @@
+GetBattleVar::
+	push hl
+	call GetBattleVarAddr
+	pop hl
+	ret
+
+GetBattleVarAddr::
+; Get variable from pair a, depending on whose turn it is.
+; There are 21 variable pairs.
+	push bc
+
+	ld hl, BattleVarPairs
+	ld c, a
+	ld b, 0
+	add hl, bc
+	add hl, bc
+
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+; Enemy turn uses the second byte instead.
+; This lets battle variable calls be side-neutral.
+	ldh a, [hBattleTurn]
+	and a
+	jr z, .getvar
+	inc hl
+
+.getvar
+; var id
+	ld a, [hl]
+	ld c, a
+	ld b, 0
+
+	ld hl, BattleVarLocations
+	add hl, bc
+	add hl, bc
+
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+	ld a, [hl]
+
+	pop bc
+	ret
+
+BattleVarPairs:
+; entries correspond to BATTLE_VARS_* constants
+	table_width 2, BattleVarPairs
+	dw .Substatus1
+	dw .Substatus2
+	dw .Substatus3
+	dw .Substatus4
+	dw .Substatus5
+	dw .Substatus1Opp
+	dw .Substatus2Opp
+	dw .Substatus3Opp
+	dw .Substatus4Opp
+	dw .Substatus5Opp
+	dw .Status
+	dw .StatusOpp
+	dw .MoveAnim
+	dw .MoveEffect
+	dw .MovePower
+	dw .MoveType
+	dw .CurMove
+	dw .LastCounter
+	dw .LastCounterOpp
+	dw .LastMove
+	dw .LastMoveOpp
+	assert_table_length NUM_BATTLE_VARS
+
+;                   player                 enemy
+.Substatus1:     db PLAYER_SUBSTATUS_1,    ENEMY_SUBSTATUS_1
+.Substatus1Opp:  db ENEMY_SUBSTATUS_1,     PLAYER_SUBSTATUS_1
+.Substatus2:     db PLAYER_SUBSTATUS_2,    ENEMY_SUBSTATUS_2
+.Substatus2Opp:  db ENEMY_SUBSTATUS_2,     PLAYER_SUBSTATUS_2
+.Substatus3:     db PLAYER_SUBSTATUS_3,    ENEMY_SUBSTATUS_3
+.Substatus3Opp:  db ENEMY_SUBSTATUS_3,     PLAYER_SUBSTATUS_3
+.Substatus4:     db PLAYER_SUBSTATUS_4,    ENEMY_SUBSTATUS_4
+.Substatus4Opp:  db ENEMY_SUBSTATUS_4,     PLAYER_SUBSTATUS_4
+.Substatus5:     db PLAYER_SUBSTATUS_5,    ENEMY_SUBSTATUS_5
+.Substatus5Opp:  db ENEMY_SUBSTATUS_5,     PLAYER_SUBSTATUS_5
+.Status:         db PLAYER_STATUS,         ENEMY_STATUS
+.StatusOpp:      db ENEMY_STATUS,          PLAYER_STATUS
+.MoveAnim:       db PLAYER_MOVE_ANIMATION, ENEMY_MOVE_ANIMATION
+.MoveEffect:     db PLAYER_MOVE_EFFECT,    ENEMY_MOVE_EFFECT
+.MovePower:      db PLAYER_MOVE_POWER,     ENEMY_MOVE_POWER
+.MoveType:       db PLAYER_MOVE_TYPE,      ENEMY_MOVE_TYPE
+.CurMove:        db PLAYER_CUR_MOVE,       ENEMY_CUR_MOVE
+.LastCounter:    db PLAYER_COUNTER_MOVE,   ENEMY_COUNTER_MOVE
+.LastCounterOpp: db ENEMY_COUNTER_MOVE,    PLAYER_COUNTER_MOVE
+.LastMove:       db PLAYER_LAST_MOVE,      ENEMY_LAST_MOVE
+.LastMoveOpp:    db ENEMY_LAST_MOVE,       PLAYER_LAST_MOVE
+
+BattleVarLocations:
+; entries correspond to PLAYER_* and ENEMY_* constants
+	table_width 2 + 2, BattleVarLocations
+	dw wPlayerSubStatus1,          wEnemySubStatus1
+	dw wPlayerSubStatus2,          wEnemySubStatus2
+	dw wPlayerSubStatus3,          wEnemySubStatus3
+	dw wPlayerSubStatus4,          wEnemySubStatus4
+	dw wPlayerSubStatus5,          wEnemySubStatus5
+	dw wBattleMonStatus,           wEnemyMonStatus
+	dw wPlayerMoveStructAnimation, wEnemyMoveStructAnimation
+	dw wPlayerMoveStructEffect,    wEnemyMoveStructEffect
+	dw wPlayerMoveStructPower,     wEnemyMoveStructPower
+	dw wPlayerMoveStructType,      wEnemyMoveStructType
+	dw wCurPlayerMove,             wCurEnemyMove
+	dw wLastPlayerCounterMove,     wLastEnemyCounterMove
+	dw wLastPlayerMove,            wLastEnemyMove
+	assert_table_length NUM_BATTLE_VAR_LOCATION_PAIRS

home/call_regs.asm

@@ -0,0 +1,8 @@
+; Register aliases
+
+_hl_::
+	jp hl
+
+_de_::
+	push de
+	ret

home/clear_sprites.asm

@@ -0,0 +1,23 @@
+ClearSprites::
+; Erase OAM data
+	ld hl, wShadowOAM
+	ld b, wShadowOAMEnd - wShadowOAM
+	xor a
+.loop
+	ld [hli], a
+	dec b
+	jr nz, .loop
+	ret
+
+HideSprites::
+; Set all OAM y-positions to 160 to hide them offscreen
+	ld hl, wShadowOAMSprite00YCoord
+	ld de, SPRITEOAMSTRUCT_LENGTH
+	ld b, NUM_SPRITE_OAM_STRUCTS
+	ld a, SCREEN_WIDTH_PX
+.loop
+	ld [hl], a ; y
+	add hl, de
+	dec b
+	jr nz, .loop
+	ret

home/compare.asm

@@ -0,0 +1,35 @@
+CompareBytes::
+; Compare c bytes at de and hl.
+; Return z if they all match.
+.loop
+	ld a, [de]
+	cp [hl]
+	ret nz
+	inc de
+	inc hl
+	dec c
+	jr nz, .loop
+	ret
+
+CompareBytesLong::
+; Compare bc bytes at de and hl.
+; Return carry if they all match.
+.loop
+	ld a, [de]
+	cp [hl]
+	jr nz, .diff
+
+	inc de
+	inc hl
+	dec bc
+
+	ld a, b
+	or c
+	jr nz, .loop
+
+	scf
+	ret
+
+.diff:
+	and a
+	ret

home/copy.asm

@@ -0,0 +1,131 @@
+CopyBytes::
+; copy bc bytes from hl to de
+	inc b ; we bail the moment b hits 0, so include the last run
+	inc c ; same thing; include last byte
+	jr .HandleLoop
+.CopyByte:
+	ld a, [hli]
+	ld [de], a
+	inc de
+.HandleLoop:
+	dec c
+	jr nz, .CopyByte
+	dec b
+	jr nz, .CopyByte
+	ret
+
+SwapBytes::
+; swap bc bytes between hl and de
+.Loop:
+	; stash [hl] away on the stack
+	ld a, [hl]
+	push af
+
+	; copy a byte from [de] to [hl]
+	ld a, [de]
+	ld [hli], a
+
+	; retrieve the previous value of [hl]; put it in [de]
+	pop af
+	ld [de], a
+	inc de
+
+	; handle loop stuff
+	dec bc
+	ld a, b
+	or c
+	jr nz, .Loop
+	ret
+
+ByteFill::
+; fill bc bytes with the value of a, starting at hl
+	inc b ; we bail the moment b hits 0, so include the last run
+	inc c ; same thing; include last byte
+	jr .HandleLoop
+.PutByte:
+	ld [hli], a
+.HandleLoop:
+	dec c
+	jr nz, .PutByte
+	dec b
+	jr nz, .PutByte
+	ret
+
+GetFarByte::
+; retrieve a single byte from a:hl, and return it in a.
+	; bankswitch to new bank
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+
+	; get byte from new bank
+	ld a, [hl]
+	ldh [hFarByte], a
+
+	; bankswitch to previous bank
+	pop af
+	rst Bankswitch
+
+	; return retrieved value in a
+	ldh a, [hFarByte]
+	ret
+
+GetFarWord::
+; retrieve a word from a:hl, and return it in hl.
+	; bankswitch to new bank
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+
+	; get word from new bank, put it in hl
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+	; bankswitch to previous bank and return
+	pop af
+	rst Bankswitch
+	ret
+
+FarCopyWRAM::
+	ldh [hTempBank], a
+	ldh a, [rSVBK]
+	push af
+	ldh a, [hTempBank]
+	ldh [rSVBK], a
+
+	call CopyBytes
+
+	pop af
+	ldh [rSVBK], a
+	ret
+
+GetFarWRAMByte::
+	ldh [hTempBank], a
+	ldh a, [rSVBK]
+	push af
+	ldh a, [hTempBank]
+	ldh [rSVBK], a
+	ld a, [hl]
+	ldh [hFarByte], a
+	pop af
+	ldh [rSVBK], a
+	ldh a, [hFarByte]
+	ret
+
+GetFarWRAMWord:: ; unreferenced
+	ldh [hTempBank], a
+	ldh a, [rSVBK]
+	push af
+	ldh a, [hTempBank]
+	ldh [rSVBK], a
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	pop af
+	ldh [rSVBK], a
+	ret

home/copy_name.asm

@@ -0,0 +1,36 @@
+CopyName1::
+; Copies the name from de to wStringBuffer2
+	ld hl, wStringBuffer2
+
+CopyName2::
+; Copies the name from de to hl
+.loop
+	ld a, [de]
+	inc de
+	ld [hli], a
+	cp "@"
+	jr nz, .loop
+	ret
+
+CopyStringWithTerminator::
+	; in: hl = source, de = destination, c = length (non-zero)
+	; out: clobbers all but b
+	dec c
+.copy_loop
+	ld a, [hli]
+	ld [de], a
+	inc de
+	cp "@"
+	jr z, .clear_loop
+	dec c
+	jr nz, .copy_loop
+	ld a, "@"
+	ld [de], a
+	ret
+
+.clear_loop
+	ld [de], a
+	inc de
+	dec c
+	jr nz, .clear_loop
+	ret

home/copy_tilemap.asm

@@ -0,0 +1,35 @@
+LoadTilemapToTempTilemap::
+; Load wTilemap into wTempTilemap
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wTempTilemap)
+	ldh [rSVBK], a
+	hlcoord 0, 0
+	decoord 0, 0, wTempTilemap
+	ld bc, wTilemapEnd - wTilemap
+	call CopyBytes
+	pop af
+	ldh [rSVBK], a
+	ret
+
+SafeLoadTempTilemapToTilemap::
+	xor a
+	ldh [hBGMapMode], a
+	call LoadTempTilemapToTilemap
+	ld a, 1
+	ldh [hBGMapMode], a
+	ret
+
+LoadTempTilemapToTilemap::
+; Load wTempTilemap into wTilemap
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wTempTilemap)
+	ldh [rSVBK], a
+	hlcoord 0, 0, wTempTilemap
+	decoord 0, 0
+	ld bc, wTilemapEnd - wTilemap
+	call CopyBytes
+	pop af
+	ldh [rSVBK], a
+	ret

home/decompress.asm

@@ -0,0 +1,317 @@
+FarDecompress::
+; Decompress graphics data from a:hl to de.
+
+	ld [wLZBank], a
+	ldh a, [hROMBank]
+	push af
+	ld a, [wLZBank]
+	rst Bankswitch
+
+	call Decompress
+
+	pop af
+	rst Bankswitch
+	ret
+
+Decompress::
+; Pokemon GSC uses an lz variant (lz3) for compression.
+; This is mainly (but not necessarily) used for graphics.
+
+; This function decompresses lz-compressed data from hl to de.
+
+DEF LZ_END EQU $ff ; Compressed data is terminated with $ff.
+
+; A typical control command consists of:
+
+DEF LZ_CMD EQU %11100000 ; command id (bits 5-7)
+DEF LZ_LEN EQU %00011111 ; length n   (bits 0-4)
+
+; Additional parameters are read during command execution.
+
+; Commands:
+
+DEF LZ_LITERAL   EQU 0 << 5 ; Read literal data for n bytes.
+DEF LZ_ITERATE   EQU 1 << 5 ; Write the same byte for n bytes.
+DEF LZ_ALTERNATE EQU 2 << 5 ; Alternate two bytes for n bytes.
+DEF LZ_ZERO      EQU 3 << 5 ; Write 0 for n bytes.
+
+; Another class of commands reuses data from the decompressed output.
+DEF LZ_RW        EQU 2 + 5 ; bit
+
+; These commands take a signed offset to start copying from.
+; Wraparound is simulated.
+; Positive offsets (15-bit) are added to the start address.
+; Negative offsets (7-bit) are subtracted from the current position.
+
+DEF LZ_REPEAT    EQU 4 << 5 ; Repeat n bytes from the offset.
+DEF LZ_FLIP      EQU 5 << 5 ; Repeat n bitflipped bytes.
+DEF LZ_REVERSE   EQU 6 << 5 ; Repeat n bytes in reverse.
+
+; If the value in the count needs to be larger than 5 bits,
+; LZ_LONG can be used to expand the count to 10 bits.
+DEF LZ_LONG      EQU 7 << 5
+
+; A new control command is read in bits 2-4.
+; The top two bits of the length are bits 0-1.
+; Another byte is read containing the bottom 8 bits.
+DEF LZ_LONG_HI   EQU %00000011
+
+; In other words, the structure of the command becomes
+; 111xxxyy yyyyyyyy
+; x: the new control command
+; y: the length
+
+	; Save the output address
+	; for rewrite commands.
+	ld a, e
+	ld [wLZAddress], a
+	ld a, d
+	ld [wLZAddress + 1], a
+
+.Main:
+	ld a, [hl]
+	cp LZ_END
+	ret z
+
+	and LZ_CMD
+
+	cp LZ_LONG
+	jr nz, .short
+
+; The count is now 10 bits.
+
+	; Read the next 3 bits.
+	; %00011100 -> %11100000
+	ld a, [hl]
+	add a
+	add a ; << 3
+	add a
+
+	; This is our new control code.
+	and LZ_CMD
+	push af
+
+	ld a, [hli]
+	and LZ_LONG_HI
+	ld b, a
+	ld a, [hli]
+	ld c, a
+
+	; read at least 1 byte
+	inc bc
+	jr .command
+
+.short
+	push af
+
+	ld a, [hli]
+	and LZ_LEN
+	ld c, a
+	ld b, 0
+
+	; read at least 1 byte
+	inc c
+
+.command
+	; Increment loop counts.
+	; We bail the moment they hit 0.
+	inc b
+	inc c
+
+	pop af
+
+	bit LZ_RW, a
+	jr nz, .rewrite
+
+	cp LZ_ITERATE
+	jr z, .Iter
+	cp LZ_ALTERNATE
+	jr z, .Alt
+	cp LZ_ZERO
+	jr z, .Zero
+
+; Literal
+; Read literal data for bc bytes.
+.lloop
+	dec c
+	jr nz, .lnext
+	dec b
+	jp z, .Main
+
+.lnext
+	ld a, [hli]
+	ld [de], a
+	inc de
+	jr .lloop
+
+.Iter:
+; Write the same byte for bc bytes.
+	ld a, [hli]
+
+.iloop
+	dec c
+	jr nz, .inext
+	dec b
+	jp z, .Main
+
+.inext
+	ld [de], a
+	inc de
+	jr .iloop
+
+.Alt:
+; Alternate two bytes for bc bytes.
+	dec c
+	jr nz, .anext1
+	dec b
+	jp z, .adone1
+.anext1
+	ld a, [hli]
+	ld [de], a
+	inc de
+
+	dec c
+	jr nz, .anext2
+	dec b
+	jp z, .adone2
+.anext2
+	ld a, [hld]
+	ld [de], a
+	inc de
+
+	jr .Alt
+
+	; Skip past the bytes we were alternating.
+.adone1
+	inc hl
+.adone2
+	inc hl
+	jr .Main
+
+.Zero:
+; Write 0 for bc bytes.
+	xor a
+
+.zloop
+	dec c
+	jr nz, .znext
+	dec b
+	jp z, .Main
+
+.znext
+	ld [de], a
+	inc de
+	jr .zloop
+
+.rewrite
+; Repeat decompressed data from output.
+	push hl
+	push af
+
+	ld a, [hli]
+	bit 7, a ; sign
+	jr z, .positive
+
+; negative
+	; hl = de + -a
+	and %01111111
+	cpl
+	add e
+	ld l, a
+	ld a, -1
+	adc d
+	ld h, a
+	jr .ok
+
+.positive
+; Positive offsets are two bytes.
+	ld l, [hl]
+	ld h, a
+	; add to starting output address
+	ld a, [wLZAddress]
+	add l
+	ld l, a
+	ld a, [wLZAddress + 1]
+	adc h
+	ld h, a
+
+.ok
+	pop af
+
+	cp LZ_REPEAT
+	jr z, .Repeat
+	cp LZ_FLIP
+	jr z, .Flip
+	cp LZ_REVERSE
+	jr z, .Reverse
+
+; Since LZ_LONG is command 7,
+; only commands 0-6 are passed in.
+; This leaves room for an extra command 7.
+; However, lengths longer than 768
+; would be interpreted as LZ_END.
+
+; More practically, LZ_LONG is not recursive.
+; For now, it defaults to LZ_REPEAT.
+
+.Repeat:
+; Copy decompressed data for bc bytes.
+	dec c
+	jr nz, .rnext
+	dec b
+	jr z, .donerw
+
+.rnext
+	ld a, [hli]
+	ld [de], a
+	inc de
+	jr .Repeat
+
+.Flip:
+; Copy bitflipped decompressed data for bc bytes.
+	dec c
+	jr nz, .fnext
+	dec b
+	jp z, .donerw
+
+.fnext
+	ld a, [hli]
+	push bc
+	lb bc, 0, 8
+
+.floop
+	rra
+	rl b
+	dec c
+	jr nz, .floop
+
+	ld a, b
+	pop bc
+
+	ld [de], a
+	inc de
+	jr .Flip
+
+.Reverse:
+; Copy reversed decompressed data for bc bytes.
+	dec c
+	jr nz, .rvnext
+
+	dec b
+	jp z, .donerw
+
+.rvnext
+	ld a, [hld]
+	ld [de], a
+	inc de
+	jr .Reverse
+
+.donerw
+	pop hl
+
+	bit 7, [hl]
+	jr nz, .next
+	inc hl ; positive offset is two bytes
+.next
+	inc hl
+	jp .Main

home/delay.asm

@@ -0,0 +1,20 @@
+DelayFrame::
+; Wait for one frame
+	ld a, 1
+	ld [wVBlankOccurred], a
+
+; Wait for the next VBlank, halting to conserve battery
+.halt
+	halt
+	nop
+	ld a, [wVBlankOccurred]
+	and a
+	jr nz, .halt
+	ret
+
+DelayFrames::
+; Wait c frames
+	call DelayFrame
+	dec c
+	jr nz, DelayFrames
+	ret

home/double_speed.asm

@@ -0,0 +1,27 @@
+; The CGB hardware introduces Double Speed Mode.
+; While active, the clock speed is doubled.
+
+; The hardware can switch between normal speed
+; and double speed at any time, but LCD output
+; collapses during the switch.
+
+DoubleSpeed::
+	ld hl, rKEY1
+	bit 7, [hl]
+	jr z, SwitchSpeed
+	ret
+
+NormalSpeed::
+	ld hl, rKEY1
+	bit 7, [hl]
+	ret z
+
+SwitchSpeed::
+	set 0, [hl]
+	xor a
+	ldh [rIF], a
+	ldh [rIE], a
+	ld a, $30
+	ldh [rJOYP], a
+	stop ; rgbasm adds a nop after this instruction by default
+	ret

home/fade.asm

@@ -0,0 +1,107 @@
+; Functions to fade the screen in and out.
+
+RotateFourPalettesRight::
+	ldh a, [hCGB]
+	and a
+	jr z, .dmg
+	ld hl, IncGradGBPalTable_00
+	ld b, 4
+	jr RotatePalettesRight
+
+.dmg
+	ld hl, IncGradGBPalTable_08
+	ld b, 4
+	jr RotatePalettesRight
+
+RotateThreePalettesRight::
+	ldh a, [hCGB]
+	and a
+	jr z, .dmg
+	ld hl, IncGradGBPalTable_05
+	ld b, 3
+	jr RotatePalettesRight
+
+.dmg
+	ld hl, IncGradGBPalTable_13
+	ld b, 3
+RotatePalettesRight::
+; Rotate palettes to the right and fill with loaded colors from the left
+; If we're already at the leftmost color, fill with the leftmost color
+	push de
+	ld a, [hli]
+	call DmgToCgbBGPals
+	ld a, [hli]
+	ld e, a
+	ld a, [hli]
+	ld d, a
+	call DmgToCgbObjPals
+	ld c, 8
+	call DelayFrames
+	pop de
+	dec b
+	jr nz, RotatePalettesRight
+	ret
+
+RotateFourPalettesLeft::
+	ldh a, [hCGB]
+	and a
+	jr z, .dmg
+	ld hl, IncGradGBPalTable_04 - 1
+	ld b, 4
+	jr RotatePalettesLeft
+
+.dmg
+	ld hl, IncGradGBPalTable_12 - 1
+	ld b, 4
+	jr RotatePalettesLeft
+
+RotateThreePalettesLeft::
+	ldh a, [hCGB]
+	and a
+	jr z, .dmg
+	ld hl, IncGradGBPalTable_07 - 1
+	ld b, 3
+	jr RotatePalettesLeft
+
+.dmg
+	ld hl, IncGradGBPalTable_15 - 1
+	ld b, 3
+RotatePalettesLeft::
+; Rotate palettes to the left and fill with loaded colors from the right
+; If we're already at the rightmost color, fill with the rightmost color
+	push de
+	ld a, [hld]
+	ld d, a
+	ld a, [hld]
+	ld e, a
+	call DmgToCgbObjPals
+	ld a, [hld]
+	call DmgToCgbBGPals
+	ld c, 8
+	call DelayFrames
+	pop de
+	dec b
+	jr nz, RotatePalettesLeft
+	ret
+
+IncGradGBPalTable_00:: dc 3,3,3,3, 3,3,3,3, 3,3,3,3
+IncGradGBPalTable_01:: dc 3,3,3,2, 3,3,3,2, 3,3,3,2
+IncGradGBPalTable_02:: dc 3,3,2,1, 3,3,2,1, 3,3,2,1
+IncGradGBPalTable_03:: dc 3,2,1,0, 3,2,1,0, 3,2,1,0
+
+IncGradGBPalTable_04:: dc 3,2,1,0, 3,2,1,0, 3,2,1,0
+IncGradGBPalTable_05:: dc 2,1,0,0, 2,1,0,0, 2,1,0,0
+IncGradGBPalTable_06:: dc 1,0,0,0, 1,0,0,0, 1,0,0,0
+
+IncGradGBPalTable_07:: dc 0,0,0,0, 0,0,0,0, 0,0,0,0
+;                           bgp      obp1     obp2
+IncGradGBPalTable_08:: dc 3,3,3,3, 3,3,3,3, 3,3,3,3
+IncGradGBPalTable_09:: dc 3,3,3,2, 3,3,3,2, 3,3,2,0
+IncGradGBPalTable_10:: dc 3,3,2,1, 3,2,1,0, 3,2,1,0
+IncGradGBPalTable_11:: dc 3,2,1,0, 3,1,0,0, 3,2,0,0
+
+IncGradGBPalTable_12:: dc 3,2,1,0, 3,1,0,0, 3,2,0,0
+IncGradGBPalTable_13:: dc 2,1,0,0, 2,0,0,0, 2,1,0,0
+IncGradGBPalTable_14:: dc 1,0,0,0, 1,0,0,0, 1,0,0,0
+
+IncGradGBPalTable_15:: dc 0,0,0,0, 0,0,0,0, 0,0,0,0

home/farcall.asm

@@ -0,0 +1,48 @@
+FarCall_de::
+; Call a:de.
+; Preserves other registers.
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+	call FarCall_JumpToDE
+	jr ReturnFarCall
+
+FarCall_JumpToDE:
+	push de
+	ret
+
+FarCall_hl::
+; Call a:hl.
+; Preserves other registers.
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+	call FarCall_JumpToHL
+	; fallthrough
+
+ReturnFarCall::
+; We want to retain the contents of f.
+; To do this, we can pop to bc instead of af.
+	ld a, b
+	ld [wFarCallBC], a
+	ld a, c
+	ld [wFarCallBC + 1], a
+
+; Restore the working bank.
+	pop bc
+	ld a, b
+	rst Bankswitch
+
+; Restore the contents of bc.
+	ld a, [wFarCallBC]
+	ld b, a
+	ld a, [wFarCallBC + 1]
+	ld c, a
+	ret
+
+FarCall_JumpToHL::
+	jp hl

home/flag.asm

@@ -0,0 +1,113 @@
+ResetMapBufferEventFlags::
+	xor a
+	ld hl, wEventFlags
+	ld [hli], a
+	ret
+
+ResetBikeFlags::
+	xor a
+	ld hl, wBikeFlags
+	ld [hli], a
+	ld [hl], a
+	ret
+
+ResetFlashIfOutOfCave::
+	ld a, [wEnvironment]
+	cp ROUTE
+	jr z, .outdoors
+	cp TOWN
+	jr z, .outdoors
+	ret
+
+.outdoors
+	ld hl, wStatusFlags
+	res STATUSFLAGS_FLASH_F, [hl]
+	ret
+
+EventFlagAction::
+	ld hl, wEventFlags
+	call FlagAction
+	ret
+
+FlagAction::
+; Perform action b on bit de in flag array hl.
+
+; inputs:
+; b: function
+;    0  RESET_FLAG  clear bit
+;    1  SET_FLAG    set bit
+;    2  CHECK_FLAG  check bit
+; de: bit number
+; hl: pointer to the flag array
+
+	; get index within the byte
+	ld a, e
+	and 7
+
+	; shift de right by three bits (get the index within memory)
+rept 3
+	srl d
+	rr e
+endr
+	add hl, de
+
+	; implement a decoder
+	ld c, 1
+	rrca
+	jr nc, .one
+	rlc c
+.one
+	rrca
+	jr nc, .two
+	rlc c
+	rlc c
+.two
+	rrca
+	jr nc, .three
+	swap c
+.three
+
+	; check b's value: 0, 1, 2
+	ld a, b
+	cp SET_FLAG
+	jr c, .clearbit ; RESET_FLAG
+	jr z, .setbit ; SET_FLAG
+
+	; check bit
+	ld a, [hl]
+	and c
+	ld c, a
+	ret
+
+.setbit
+	; set bit
+	ld a, [hl]
+	or c
+	ld [hl], a
+	ret
+
+.clearbit
+	; clear bit
+	ld a, c
+	cpl
+	and [hl]
+	ld [hl], a
+	ret
+
+CheckReceivedDex::
+	ld de, ENGINE_POKEDEX
+	ld b, CHECK_FLAG
+	farcall EngineFlagAction
+	ld a, c
+	and a
+	ret
+
+xor_a::
+	xor a
+	ret
+
+xor_a_dec_a::
+	xor a
+	dec a
+	ret
+

home/game_time.asm

@@ -0,0 +1,118 @@
+ResetGameTime::
+	xor a
+	ld [wGameTimeCap], a
+	ld [wGameTimeHours], a
+	ld [wGameTimeHours + 1], a
+	ld [wGameTimeMinutes], a
+	ld [wGameTimeSeconds], a
+	ld [wGameTimeFrames], a
+	ret
+
+GameTimer::
+	nop
+
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wGameTime)
+	ldh [rSVBK], a
+
+	call .Function
+
+	pop af
+	ldh [rSVBK], a
+	ret
+
+.Function:
+; Increment the game timer by one frame.
+; The game timer is capped at 999:59:59.00.
+
+; Don't update if game logic is paused.
+	ld a, [wGameLogicPaused]
+	and a
+	ret nz
+
+; Is the timer paused?
+	ld hl, wGameTimerPaused
+	bit GAME_TIMER_PAUSED_F, [hl]
+	ret z
+
+; Is the timer already capped?
+	ld hl, wGameTimeCap
+	bit 0, [hl]
+	ret nz
+
+; +1 frame
+	ld hl, wGameTimeFrames
+	ld a, [hl]
+	inc a
+
+	cp 60 ; frames/second
+	jr nc, .second
+
+	ld [hl], a
+	ret
+
+.second
+	xor a
+	ld [hl], a
+
+; +1 second
+	ld hl, wGameTimeSeconds
+	ld a, [hl]
+	inc a
+
+	cp 60 ; seconds/minute
+	jr nc, .minute
+
+	ld [hl], a
+	ret
+
+.minute
+	xor a
+	ld [hl], a
+
+; +1 minute
+	ld hl, wGameTimeMinutes
+	ld a, [hl]
+	inc a
+
+	cp 60 ; minutes/hour
+	jr nc, .hour
+
+	ld [hl], a
+	ret
+
+.hour
+	xor a
+	ld [hl], a
+
+; +1 hour
+	ld a, [wGameTimeHours]
+	ld h, a
+	ld a, [wGameTimeHours + 1]
+	ld l, a
+	inc hl
+
+; Cap the timer after 1000 hours.
+	ld a, h
+	cp HIGH(1000)
+	jr c, .ok
+
+	ld a, l
+	cp LOW(1000)
+	jr c, .ok
+
+	ld hl, wGameTimeCap
+	set 0, [hl]
+
+	ld a, 59 ; 999:59:59.00
+	ld [wGameTimeMinutes], a
+	ld [wGameTimeSeconds], a
+	ret
+
+.ok
+	ld a, h
+	ld [wGameTimeHours], a
+	ld a, l
+	ld [wGameTimeHours + 1], a
+	ret

home/gfx.asm

@@ -0,0 +1,392 @@
+DEF TILES_PER_CYCLE EQU 8
+DEF MOBILE_TILES_PER_CYCLE EQU 6
+
+Get2bppViaHDMA::
+	ldh a, [rLCDC]
+	bit rLCDC_ENABLE, a
+	jp z, Copy2bpp
+
+	homecall HDMATransfer2bpp
+
+	ret
+
+Get1bppViaHDMA::
+	ldh a, [rLCDC]
+	bit rLCDC_ENABLE, a
+	jp z, Copy1bpp
+
+	homecall HDMATransfer1bpp
+
+	ret
+
+FarCopyBytesDouble_DoubleBankSwitch::
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+
+	call FarCopyBytesDouble
+
+	pop af
+	rst Bankswitch
+	ret
+
+SafeHDMATransfer: ; unreferenced
+	dec c
+	ldh a, [hBGMapMode]
+	push af
+	xor a
+	ldh [hBGMapMode], a
+	ldh a, [hROMBank]
+	push af
+	ld a, b
+	rst Bankswitch
+
+.loop
+; load the source and target MSB and LSB
+	ld a, d
+	ldh [rHDMA1], a ; source MSB
+	ld a, e
+	and $f0
+	ldh [rHDMA2], a ; source LSB
+	ld a, h
+	and $1f
+	ldh [rHDMA3], a ; target MSB
+	ld a, l
+	and $f0
+	ldh [rHDMA4], a ; target LSB
+; stop when c < TILES_PER_CYCLE
+	ld a, c
+	cp TILES_PER_CYCLE
+	jr c, .done
+; decrease c by TILES_PER_CYCLE
+	sub TILES_PER_CYCLE
+	ld c, a
+; DMA transfer state
+	ld a, $f
+	ldh [hDMATransfer], a
+	call DelayFrame
+; add $100 to hl and de
+	ld a, l
+	add LOW($100)
+	ld l, a
+	ld a, h
+	adc HIGH($100)
+	ld h, a
+	ld a, e
+	add LOW($100)
+	ld e, a
+	ld a, d
+	adc HIGH($100)
+	ld d, a
+	jr .loop
+
+.done
+	ld a, c
+	and $7f ; pretty silly, considering at most bits 0-2 would be set
+	ldh [hDMATransfer], a
+	call DelayFrame
+	pop af
+	rst Bankswitch
+
+	pop af
+	ldh [hBGMapMode], a
+	ret
+
+UpdatePlayerSprite::
+	farcall _UpdatePlayerSprite
+	ret
+
+LoadStandardFont::
+	farcall _LoadStandardFont
+	ret
+
+LoadFontsBattleExtra::
+	farcall _LoadFontsBattleExtra
+	ret
+
+LoadFontsExtra::
+	farcall _LoadFontsExtra1
+	farcall _LoadFontsExtra2
+	ret
+
+LoadFontsExtra2: ; unreferenced
+	farcall _LoadFontsExtra2
+	ret
+
+DecompressRequest2bpp::
+	push de
+	ld a, BANK(sScratch)
+	call OpenSRAM
+	push bc
+
+	ld de, sScratch
+	ld a, b
+	call FarDecompress
+
+	pop bc
+	pop hl
+
+	ld de, sScratch
+	call Request2bpp
+	call CloseSRAM
+	ret
+
+FarCopyBytes::
+; copy bc bytes from a:hl to de
+
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+
+	call CopyBytes
+
+	pop af
+	rst Bankswitch
+	ret
+
+FarCopyBytesDouble:
+; Copy bc bytes from a:hl to bc*2 bytes at de,
+; doubling each byte in the process.
+
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+
+; switcheroo, de <> hl
+	ld a, h
+	ld h, d
+	ld d, a
+	ld a, l
+	ld l, e
+	ld e, a
+
+	inc b
+	inc c
+	jr .dec
+
+.loop
+	ld a, [de]
+	inc de
+	ld [hli], a
+	ld [hli], a
+.dec
+	dec c
+	jr nz, .loop
+	dec b
+	jr nz, .loop
+
+	pop af
+	rst Bankswitch
+	ret
+
+Request2bpp::
+; Load 2bpp at b:de to occupy c tiles of hl.
+	ldh a, [hBGMapMode]
+	push af
+	xor a
+	ldh [hBGMapMode], a
+
+	ldh a, [hROMBank]
+	push af
+	ld a, b
+	rst Bankswitch
+
+	ldh a, [hTilesPerCycle]
+	push af
+	ld a, TILES_PER_CYCLE
+	ldh [hTilesPerCycle], a
+
+	ld a, [wLinkMode]
+	cp LINK_MOBILE
+	jr nz, .NotMobile
+	ldh a, [hMobile]
+	and a
+	jr nz, .NotMobile
+	ld a, MOBILE_TILES_PER_CYCLE
+	ldh [hTilesPerCycle], a
+
+.NotMobile:
+	ld a, e
+	ld [wRequested2bppSource], a
+	ld a, d
+	ld [wRequested2bppSource + 1], a
+	ld a, l
+	ld [wRequested2bppDest], a
+	ld a, h
+	ld [wRequested2bppDest + 1], a
+.loop
+	ld a, c
+	ld hl, hTilesPerCycle
+	cp [hl]
+	jr nc, .cycle
+
+	ld [wRequested2bppSize], a
+.wait
+	call DelayFrame
+	ld a, [wRequested2bppSize]
+	and a
+	jr nz, .wait
+
+	pop af
+	ldh [hTilesPerCycle], a
+
+	pop af
+	rst Bankswitch
+
+	pop af
+	ldh [hBGMapMode], a
+	ret
+
+.cycle
+	ldh a, [hTilesPerCycle]
+	ld [wRequested2bppSize], a
+
+.wait2
+	call DelayFrame
+	ld a, [wRequested2bppSize]
+	and a
+	jr nz, .wait2
+
+	ld a, c
+	ld hl, hTilesPerCycle
+	sub [hl]
+	ld c, a
+	jr .loop
+
+Request1bpp::
+; Load 1bpp at b:de to occupy c tiles of hl.
+	ldh a, [hBGMapMode]
+	push af
+	xor a
+	ldh [hBGMapMode], a
+
+	ldh a, [hROMBank]
+	push af
+	ld a, b
+	rst Bankswitch
+
+	ldh a, [hTilesPerCycle]
+	push af
+	ld a, TILES_PER_CYCLE
+	ldh [hTilesPerCycle], a
+
+	ld a, [wLinkMode]
+	cp LINK_MOBILE
+	jr nz, .NotMobile
+	ldh a, [hMobile]
+	and a
+	jr nz, .NotMobile
+	ld a, MOBILE_TILES_PER_CYCLE
+	ldh [hTilesPerCycle], a
+
+.NotMobile:
+	ld a, e
+	ld [wRequested1bppSource], a
+	ld a, d
+	ld [wRequested1bppSource + 1], a
+	ld a, l
+	ld [wRequested1bppDest], a
+	ld a, h
+	ld [wRequested1bppDest + 1], a
+.loop
+	ld a, c
+	ld hl, hTilesPerCycle
+	cp [hl]
+	jr nc, .cycle
+
+	ld [wRequested1bppSize], a
+.wait
+	call DelayFrame
+	ld a, [wRequested1bppSize]
+	and a
+	jr nz, .wait
+
+	pop af
+	ldh [hTilesPerCycle], a
+
+	pop af
+	rst Bankswitch
+
+	pop af
+	ldh [hBGMapMode], a
+	ret
+
+.cycle
+	ldh a, [hTilesPerCycle]
+	ld [wRequested1bppSize], a
+
+.wait2
+	call DelayFrame
+	ld a, [wRequested1bppSize]
+	and a
+	jr nz, .wait2
+
+	ld a, c
+	ld hl, hTilesPerCycle
+	sub [hl]
+	ld c, a
+	jr .loop
+
+Get2bpp::
+; copy c 2bpp tiles from b:de to hl
+	ldh a, [rLCDC]
+	bit rLCDC_ENABLE, a
+	jp nz, Request2bpp
+	; fallthrough
+
+Copy2bpp:
+	push hl
+	ld h, d
+	ld l, e
+	pop de
+
+; bank
+	ld a, b
+
+; bc = c * LEN_2BPP_TILE
+	push af
+	swap c
+	ld a, $f
+	and c
+	ld b, a
+	ld a, $f0
+	and c
+	ld c, a
+	pop af
+
+	jp FarCopyBytes
+
+Get1bpp::
+; copy c 1bpp tiles from b:de to hl
+	ldh a, [rLCDC]
+	bit rLCDC_ENABLE, a
+	jp nz, Request1bpp
+	; fallthrough
+
+Copy1bpp::
+	push de
+	ld d, h
+	ld e, l
+
+; bank
+	ld a, b
+
+; bc = c * LEN_1BPP_TILE
+	push af
+	ld h, 0
+	ld l, c
+	add hl, hl
+	add hl, hl
+	add hl, hl
+	ld b, h
+	ld c, l
+	pop af
+
+	pop hl
+	jp FarCopyBytesDouble

home/header.asm

@@ -0,0 +1,70 @@
+; rst vectors (called through the rst instruction)
+
+SECTION "rst0", ROM0[$0000]
+	di
+	jp Start
+
+SECTION "rst8", ROM0[$0008]
+FarCall::
+	jp FarCall_hl
+
+SECTION "rst10", ROM0[$0010]
+Bankswitch::
+	ldh [hROMBank], a
+	ld [MBC3RomBank], a
+	ret
+
+SECTION "rst18", ROM0[$0018]
+	rst $38
+
+SECTION "rst20", ROM0[$0020]
+	rst $38
+
+SECTION "rst28", ROM0[$0028]
+JumpTable::
+	push de
+	ld e, a
+	ld d, 0
+	add hl, de
+	add hl, de
+	ld a, [hli]
+	ld h, [hl]
+; SECTION "rst30", ROM0[$0030]
+	ld l, a
+	pop de
+	jp hl
+
+SECTION "rst38", ROM0[$0038]
+	rst $38
+
+
+; Game Boy hardware interrupts
+
+SECTION "vblank", ROM0[$0040]
+	jp VBlank
+
+SECTION "lcd", ROM0[$0048]
+	jp LCD
+
+SECTION "timer", ROM0[$0050]
+	jp MobileTimer
+
+SECTION "serial", ROM0[$0058]
+	jp Serial
+
+SECTION "joypad", ROM0[$0060]
+	jp Joypad
+
+
+SECTION "Header", ROM0[$0100]
+
+Start::
+; Nintendo requires all Game Boy ROMs to begin with a nop ($00) and a jp ($C3)
+; to the starting address.
+	nop
+	jp _Start
+
+; The Game Boy cartridge header data is patched over by rgbfix.
+; This makes sure it doesn't get used for anything else.
+
+	ds $0150 - @, $00

home/hm_moves.asm

@@ -0,0 +1,28 @@
+; HM moves can't be forgotten
+
+IsHM::
+	cp HM01
+	jr c, .NotHM
+	scf
+	ret
+.NotHM:
+	and a
+	ret
+
+IsHMMove::
+	call GetMoveIndexFromID
+	ld b, h
+	ld c, l
+	ld hl, .HMMoves
+	ld de, 2
+	jp IsInWordArray
+
+.HMMoves:
+	dw CUT
+	dw FLY
+	dw SURF
+	dw STRENGTH
+	dw FLASH
+	dw WATERFALL
+	dw WHIRLPOOL
+	dw -1 ; end

home/indirection.asm

@@ -0,0 +1,76 @@
+LoadIndirectPointer::
+	; in: a:hl: indirect table, bc: index
+	; out: a:hl: pointer to element, b: copy of a, c: clobbered, de: preserved, zero flag: set if pointer is null
+	push de
+	ld d, a
+	ldh a, [hROMBank]
+	push af
+	ld a, d
+	rst Bankswitch
+	ld a, [hli]
+	ld e, a
+	ld a, [hli]
+	ld d, a
+	add a, a
+	jr nc, .loop
+	res 7, d
+	dec bc
+	ld a, b
+	and c
+	inc a
+	jr nz, .loop
+.null
+	ld hl, 0
+	ld b, h
+.done
+	pop af
+	rst Bankswitch
+	pop de
+	ld a, h
+	or l
+	ld a, b
+	ret
+
+.next
+	inc hl
+	inc hl
+	inc hl
+	cpl
+	inc a
+	add a, c
+	ld c, a
+	jr c, .loop ;subtracting by addition has the carry flipped
+	dec b
+.loop
+	ld a, [hli]
+	and a
+	jr z, .null
+	inc b
+	dec b
+	jr nz, .next
+	cp c
+	jr c, .next
+	jr z, .next
+
+	ld a, [hli]
+	ld b, a
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	or h
+	jr z, .done ;no point in setting them to zero if they already are
+	ld a, c
+	ld c, e
+	ld e, b
+	ld b, d
+	call AddNTimes
+	ld b, e
+	jr .done
+
+LoadDoubleIndirectPointer::
+	; for indirect tables of near pointers to data, used for structures of varying size
+	; same calling convention as LoadIndirectPointer
+	call LoadIndirectPointer
+	call nz, GetFarWord
+	ld a, b
+	ret

home/init.asm

@@ -0,0 +1,216 @@
+Reset::
+	di
+	call InitSound
+	xor a
+	ldh [hMapAnims], a
+	call ClearPalettes
+	xor a
+	ldh [rIF], a
+	ld a, 1 << VBLANK
+	ldh [rIE], a
+	ei
+
+	ld hl, wJoypadDisable
+	set JOYPAD_DISABLE_SGB_TRANSFER_F, [hl]
+
+	ld c, 32
+	call DelayFrames
+
+	jr Init
+
+_Start::
+	cp $11
+	jr z, .cgb
+	xor a ; FALSE
+	jr .load
+
+.cgb
+	ld a, TRUE
+
+.load
+	ldh [hCGB], a
+	ld a, TRUE
+	ldh [hSystemBooted], a
+
+Init::
+	di
+
+	xor a
+	ldh [rIF], a
+	ldh [rIE], a
+	ldh [rRP], a
+	ldh [rSCX], a
+	ldh [rSCY], a
+	ldh [rSB], a
+	ldh [rSC], a
+	ldh [rWX], a
+	ldh [rWY], a
+	ldh [rBGP], a
+	ldh [rOBP0], a
+	ldh [rOBP1], a
+	ldh [rTMA], a
+	ldh [rTAC], a
+	ld [wBetaTitleSequenceOpeningType], a
+
+	ld a, %100 ; Start timer at 4096Hz
+	ldh [rTAC], a
+
+.wait
+	ldh a, [rLY]
+	cp LY_VBLANK + 1
+	jr nz, .wait
+
+	xor a
+	ldh [rLCDC], a
+
+; Clear WRAM bank 0
+	ld hl, WRAM0_Begin
+	ld bc, WRAM0_End - WRAM0_Begin
+.ByteFill:
+	ld [hl], 0
+	inc hl
+	dec bc
+	ld a, b
+	or c
+	jr nz, .ByteFill
+
+	ld sp, wStackTop
+
+; Clear HRAM
+	ldh a, [hCGB]
+	push af
+	ldh a, [hSystemBooted]
+	push af
+	xor a
+	ld hl, HRAM_Begin
+	ld bc, HRAM_End - HRAM_Begin
+	call ByteFill
+	pop af
+	ldh [hSystemBooted], a
+	pop af
+	ldh [hCGB], a
+	ld a, -1
+	ldh [hSRAMBank], a
+
+	call ClearWRAM
+	ld a, 1
+	ldh [rSVBK], a
+	call ClearVRAM
+	call ClearSprites
+	call ClearsScratch
+
+	ld a, BANK(WriteOAMDMACodeToHRAM) ; aka BANK(GameInit)
+	rst Bankswitch
+
+	call WriteOAMDMACodeToHRAM
+
+	xor a
+	ldh [hMapAnims], a
+	ldh [hSCX], a
+	ldh [hSCY], a
+	ldh [rJOYP], a
+
+	ld a, $8 ; HBlank int enable
+	ldh [rSTAT], a
+
+	ld a, $90
+	ldh [hWY], a
+	ldh [rWY], a
+
+	ld a, 7
+	ldh [hWX], a
+	ldh [rWX], a
+
+	ld a, LCDC_DEFAULT ; %11100011
+	; LCD on
+	; Win tilemap 1
+	; Win on
+	; BG/Win tiledata 0
+	; BG Tilemap 0
+	; OBJ 8x8
+	; OBJ on
+	; BG on
+	ldh [rLCDC], a
+
+	ld a, CONNECTION_NOT_ESTABLISHED
+	ldh [hSerialConnectionStatus], a
+
+	farcall InitCGBPals
+
+	ld a, HIGH(vBGMap1)
+	ldh [hBGMapAddress + 1], a
+	xor a ; LOW(vBGMap1)
+	ldh [hBGMapAddress], a
+
+	farcall StartClock
+
+	xor a ; SRAM_DISABLE
+	ld [MBC3LatchClock], a
+	ld [MBC3SRamEnable], a
+
+	ldh a, [hCGB]
+	and a
+	jr z, .no_double_speed
+	call NormalSpeed
+.no_double_speed
+
+	xor a
+	ldh [rIF], a
+	ld a, IE_DEFAULT
+	ldh [rIE], a
+	ei
+
+	call DelayFrame
+
+	predef InitSGBBorder
+
+	call InitSound
+	xor a
+	ld [wMapMusic], a
+	jp GameInit
+
+ClearVRAM::
+; Wipe VRAM banks 0 and 1
+
+	ld a, 1
+	ldh [rVBK], a
+	call .clear
+
+	xor a ; 0
+	ldh [rVBK], a
+.clear
+	ld hl, VRAM_Begin
+	ld bc, VRAM_End - VRAM_Begin
+	xor a
+	call ByteFill
+	ret
+
+ClearWRAM::
+; Wipe swappable WRAM banks (1-7)
+; Assumes CGB or AGB
+
+	ld a, 1
+.bank_loop
+	push af
+	ldh [rSVBK], a
+	xor a
+	ld hl, WRAM1_Begin
+	ld bc, WRAM1_End - WRAM1_Begin
+	call ByteFill
+	pop af
+	inc a
+	cp 8
+	jr c, .bank_loop
+	ret
+
+ClearsScratch::
+; Wipe the first 32 bytes of sScratch
+
+	ld a, BANK(sScratch)
+	call OpenSRAM
+	ld hl, sScratch
+	ld bc, $20
+	xor a
+	call ByteFill
+	call CloseSRAM
+	ret

home/item.asm

@@ -0,0 +1,70 @@
+DoItemEffect::
+	farcall _DoItemEffect
+	ret
+
+CheckTossableItem::
+	push hl
+	push de
+	push bc
+	farcall _CheckTossableItem
+	pop bc
+	pop de
+	pop hl
+	ret
+
+TossItem::
+	push hl
+	push de
+	push bc
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_TossItem)
+	rst Bankswitch
+
+	call _TossItem
+
+	pop bc
+	ld a, b
+	rst Bankswitch
+	pop bc
+	pop de
+	pop hl
+	ret
+
+ReceiveItem::
+	push bc
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_ReceiveItem)
+	rst Bankswitch
+	push hl
+	push de
+
+	call _ReceiveItem
+
+	pop de
+	pop hl
+	pop bc
+	ld a, b
+	rst Bankswitch
+	pop bc
+	ret
+
+CheckItem::
+	push hl
+	push de
+	push bc
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_CheckItem)
+	rst Bankswitch
+
+	call _CheckItem
+
+	pop bc
+	ld a, b
+	rst Bankswitch
+	pop bc
+	pop de
+	pop hl
+	ret

home/joypad.asm

@@ -0,0 +1,483 @@
+Joypad::
+; Replaced by UpdateJoypad, called from VBlank instead of the useless
+; joypad interrupt.
+
+; This is a placeholder in case the interrupt is somehow enabled.
+	reti
+
+ClearJoypad::
+	xor a
+; Pressed this frame (delta)
+	ldh [hJoyPressed], a
+; Currently pressed
+	ldh [hJoyDown], a
+	ret
+
+UpdateJoypad::
+; This is called automatically every frame in VBlank.
+; Read the joypad register and translate it to something more
+; workable for use in-game. There are 8 buttons, so we can use
+; one byte to contain all player input.
+
+; Updates:
+
+; hJoypadReleased: released this frame (delta)
+; hJoypadPressed: pressed this frame (delta)
+; hJoypadDown: currently pressed
+; hJoypadSum: pressed so far
+
+; Any of these three bits can be used to disable input.
+	ld a, [wJoypadDisable]
+	and (1 << JOYPAD_DISABLE_MON_FAINT_F) | (1 << JOYPAD_DISABLE_SGB_TRANSFER_F) | (1 << 4)
+	ret nz
+
+; If we're saving, input is disabled.
+	ld a, [wGameLogicPaused]
+	and a
+	ret nz
+
+; We can only get four inputs at a time.
+; We take d-pad first for no particular reason.
+	ld a, R_DPAD
+	ldh [rJOYP], a
+; Read twice to give the request time to take.
+	ldh a, [rJOYP]
+	ldh a, [rJOYP]
+
+; The Joypad register output is in the lo nybble (inversed).
+; We make the hi nybble of our new container d-pad input.
+	cpl
+	and $f
+	swap a
+
+; We'll keep this in b for now.
+	ld b, a
+
+; Buttons make 8 total inputs (A, B, Select, Start).
+; We can fit this into one byte.
+	ld a, R_BUTTONS
+	ldh [rJOYP], a
+; Wait for input to stabilize.
+rept 6
+	ldh a, [rJOYP]
+endr
+; Buttons take the lo nybble.
+	cpl
+	and $f
+	or b
+	ld b, a
+
+; Reset the joypad register since we're done with it.
+	ld a, $30
+	ldh [rJOYP], a
+
+; To get the delta we xor the last frame's input with the new one.
+	ldh a, [hJoypadDown] ; last frame
+	ld e, a
+	xor b
+	ld d, a
+; Released this frame:
+	and e
+	ldh [hJoypadReleased], a
+; Pressed this frame:
+	ld a, d
+	and b
+	ldh [hJoypadPressed], a
+
+; Add any new presses to the list of collective presses:
+	ld c, a
+	ldh a, [hJoypadSum]
+	or c
+	ldh [hJoypadSum], a
+
+; Currently pressed:
+	ld a, b
+	ldh [hJoypadDown], a
+
+; Now that we have the input, we can do stuff with it.
+
+; For example, soft reset:
+	and A_BUTTON | B_BUTTON | SELECT | START
+	cp  A_BUTTON | B_BUTTON | SELECT | START
+	jp z, Reset
+
+	ret
+
+GetJoypad::
+; Update mirror joypad input from hJoypadDown (real input)
+
+; hJoyReleased: released this frame (delta)
+; hJoyPressed: pressed this frame (delta)
+; hJoyDown: currently pressed
+
+; bit 0 A
+;     1 B
+;     2 SELECT
+;     3 START
+;     4 RIGHT
+;     5 LEFT
+;     6 UP
+;     7 DOWN
+
+	push af
+	push hl
+	push de
+	push bc
+
+; The player input can be automated using an input stream.
+; See more below.
+	ld a, [wInputType]
+	cp AUTO_INPUT
+	jr z, .auto
+
+; To get deltas, take this and last frame's input.
+	ldh a, [hJoypadDown] ; real input
+	ld b, a
+	ldh a, [hJoyDown] ; last frame mirror
+	ld e, a
+
+; Released this frame:
+	xor b
+	ld d, a
+	and e
+	ldh [hJoyReleased], a
+
+; Pressed this frame:
+	ld a, d
+	and b
+	ldh [hJoyPressed], a
+
+; It looks like the collective presses got commented out here.
+	ld c, a
+
+; Currently pressed:
+	ld a, b
+	ldh [hJoyDown], a ; frame input
+
+.quit
+	pop bc
+	pop de
+	pop hl
+	pop af
+	ret
+
+.auto
+; Use a predetermined input stream (used in the catching tutorial).
+
+; Stream format: [input][duration]
+; A value of $ff will immediately end the stream.
+
+; Read from the input stream.
+	ldh a, [hROMBank]
+	push af
+	ld a, [wAutoInputBank]
+	rst Bankswitch
+
+	ld hl, wAutoInputAddress
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+; We only update when the input duration has expired.
+	ld a, [wAutoInputLength]
+	and a
+	jr z, .updateauto
+
+; Until then, don't change anything.
+	dec a
+	ld [wAutoInputLength], a
+	pop af
+	rst Bankswitch
+	jr .quit
+
+.updateauto
+; An input of $ff will end the stream.
+	ld a, [hli]
+	cp -1
+	jr z, .stopauto
+	ld b, a
+
+; A duration of $ff will end the stream indefinitely.
+	ld a, [hli]
+	ld [wAutoInputLength], a
+	cp -1
+	jr nz, .next
+
+; The current input is overwritten.
+	dec hl
+	dec hl
+	ld b, NO_INPUT
+	jr .finishauto
+
+.next
+; On to the next input...
+	ld a, l
+	ld [wAutoInputAddress], a
+	ld a, h
+	ld [wAutoInputAddress + 1], a
+	jr .finishauto
+
+.stopauto
+	call StopAutoInput
+	ld b, NO_INPUT
+
+.finishauto
+	pop af
+	rst Bankswitch
+	ld a, b
+	ldh [hJoyPressed], a ; pressed
+	ldh [hJoyDown], a ; input
+	jr .quit
+
+StartAutoInput::
+; Start reading automated input stream at a:hl.
+
+	ld [wAutoInputBank], a
+	ld a, l
+	ld [wAutoInputAddress], a
+	ld a, h
+	ld [wAutoInputAddress + 1], a
+; Start reading the stream immediately.
+	xor a
+	ld [wAutoInputLength], a
+; Reset input mirrors.
+	xor a
+	ldh [hJoyPressed], a ; pressed this frame
+	ldh [hJoyReleased], a ; released this frame
+	ldh [hJoyDown], a ; currently pressed
+
+	ld a, AUTO_INPUT
+	ld [wInputType], a
+	ret
+
+StopAutoInput::
+; Clear variables related to automated input.
+	xor a
+	ld [wAutoInputBank], a
+	ld [wAutoInputAddress], a
+	ld [wAutoInputAddress + 1], a
+	ld [wAutoInputLength], a
+; Back to normal input.
+	ld [wInputType], a
+	ret
+
+JoyTitleScreenInput:: ; unreferenced
+.loop
+	call DelayFrame
+
+	push bc
+	call JoyTextDelay
+	pop bc
+
+; Save data can be deleted by pressing Up + B + Select.
+	ldh a, [hJoyDown]
+	cp D_UP | SELECT | B_BUTTON
+	jr z, .keycombo
+
+; Press Start or A to start the game.
+	ldh a, [hJoyLast]
+	and START | A_BUTTON
+	jr nz, .keycombo
+
+	dec c
+	jr nz, .loop
+
+	and a
+	ret
+
+.keycombo
+	scf
+	ret
+
+JoyWaitAorB::
+.loop
+	call DelayFrame
+	call GetJoypad
+	ldh a, [hJoyPressed]
+	and A_BUTTON | B_BUTTON
+	ret nz
+	call UpdateTimeAndPals
+	jr .loop
+
+WaitButton::
+	ldh a, [hOAMUpdate]
+	push af
+	ld a, 1
+	ldh [hOAMUpdate], a
+	call WaitBGMap
+	call JoyWaitAorB
+	pop af
+	ldh [hOAMUpdate], a
+	ret
+
+JoyTextDelay::
+	call GetJoypad
+	ldh a, [hInMenu]
+	and a
+	ldh a, [hJoyPressed]
+	jr z, .ok
+	ldh a, [hJoyDown]
+.ok
+	ldh [hJoyLast], a
+	ldh a, [hJoyPressed]
+	and a
+	jr z, .checkframedelay
+	ld a, 15
+	ld [wTextDelayFrames], a
+	ret
+
+.checkframedelay
+	ld a, [wTextDelayFrames]
+	and a
+	jr z, .restartframedelay
+	xor a
+	ldh [hJoyLast], a
+	ret
+
+.restartframedelay
+	ld a, 5
+	ld [wTextDelayFrames], a
+	ret
+
+WaitPressAorB_BlinkCursor::
+; Show a blinking cursor in the lower right-hand
+; corner of a textbox and wait until A or B is
+; pressed.
+;
+; NOTE: The cursor has to be shown before calling
+; this function or no cursor will be shown at all.
+	ldh a, [hMapObjectIndex]
+	push af
+	ldh a, [hObjectStructIndex]
+	push af
+	xor a
+	ldh [hMapObjectIndex], a
+	ld a, 6
+	ldh [hObjectStructIndex], a
+
+.loop
+	push hl
+	hlcoord 18, 17
+	call BlinkCursor
+	pop hl
+
+	call JoyTextDelay
+	ldh a, [hJoyLast]
+	and A_BUTTON | B_BUTTON
+	jr z, .loop
+
+	pop af
+	ldh [hObjectStructIndex], a
+	pop af
+	ldh [hMapObjectIndex], a
+	ret
+
+SimpleWaitPressAorB::
+.loop
+	call JoyTextDelay
+	ldh a, [hJoyLast]
+	and A_BUTTON | B_BUTTON
+	jr z, .loop
+	ret
+
+PromptButton::
+; Show a blinking cursor in the lower right-hand
+; corner of a textbox and wait until A or B is
+; pressed, afterwards, play a sound.
+	ld a, [wLinkMode]
+	and a
+	jr nz, .link
+	call .wait_input
+	push de
+	ld de, SFX_READ_TEXT_2
+	call PlaySFX
+	pop de
+	ret
+
+.link
+	ld c, 65
+	jp DelayFrames
+
+.wait_input
+	ldh a, [hOAMUpdate]
+	push af
+	ld a, $1
+	ldh [hOAMUpdate], a
+	ld a, [wInputType]
+	or a
+	jr z, .input_wait_loop
+	farcall _DudeAutoInput_A
+
+.input_wait_loop
+	call .blink_cursor
+	call JoyTextDelay
+	ldh a, [hJoyPressed]
+	and A_BUTTON | B_BUTTON
+	jr nz, .received_input
+	call UpdateTimeAndPals
+	ld a, $1
+	ldh [hBGMapMode], a
+	call DelayFrame
+	jr .input_wait_loop
+
+.received_input
+	pop af
+	ldh [hOAMUpdate], a
+	ret
+
+.blink_cursor
+	ldh a, [hVBlankCounter]
+	and %00010000 ; bit 4, a
+	jr z, .cursor_off
+	ld a, "▼"
+	jr .load_cursor_state
+
+.cursor_off
+	lda_coord 17, 17
+
+.load_cursor_state
+	ldcoord_a 18, 17
+	ret
+
+BlinkCursor::
+	push bc
+	ld a, [hl]
+	ld b, a
+	ld a, "▼"
+	cp b
+	pop bc
+	jr nz, .place_arrow
+	ldh a, [hMapObjectIndex]
+	dec a
+	ldh [hMapObjectIndex], a
+	ret nz
+	ldh a, [hObjectStructIndex]
+	dec a
+	ldh [hObjectStructIndex], a
+	ret nz
+	ld a, "─"
+	ld [hl], a
+	ld a, -1
+	ldh [hMapObjectIndex], a
+	ld a, 6
+	ldh [hObjectStructIndex], a
+	ret
+
+.place_arrow
+	ldh a, [hMapObjectIndex]
+	and a
+	ret z
+	dec a
+	ldh [hMapObjectIndex], a
+	ret nz
+	dec a
+	ldh [hMapObjectIndex], a
+	ldh a, [hObjectStructIndex]
+	dec a
+	ldh [hObjectStructIndex], a
+	ret nz
+	ld a, 6
+	ldh [hObjectStructIndex], a
+	ld a, "▼"
+	ld [hl], a
+	ret

home/lcd.asm

@@ -0,0 +1,63 @@
+; LCD handling
+
+LCD::
+	push af
+	ldh a, [hLCDCPointer]
+	and a
+	jr z, .done
+
+; At this point it's assumed we're in BANK(wLYOverrides)!
+	push bc
+	ldh a, [rLY]
+	ld c, a
+	ld b, HIGH(wLYOverrides)
+	ld a, [bc]
+	ld b, a
+	ldh a, [hLCDCPointer]
+	ld c, a
+	ld a, b
+	ldh [c], a
+	pop bc
+
+.done
+	pop af
+	reti
+
+DisableLCD::
+; Turn the LCD off
+
+; Don't need to do anything if the LCD is already off
+	ldh a, [rLCDC]
+	bit rLCDC_ENABLE, a
+	ret z
+
+	xor a
+	ldh [rIF], a
+	ldh a, [rIE]
+	ld b, a
+
+; Disable VBlank
+	res VBLANK, a
+	ldh [rIE], a
+
+.wait
+; Wait until VBlank would normally happen
+	ldh a, [rLY]
+	cp LY_VBLANK + 1
+	jr nz, .wait
+
+	ldh a, [rLCDC]
+	and ~(1 << rLCDC_ENABLE)
+	ldh [rLCDC], a
+
+	xor a
+	ldh [rIF], a
+	ld a, b
+	ldh [rIE], a
+	ret
+
+EnableLCD::
+	ldh a, [rLCDC]
+	set rLCDC_ENABLE, a
+	ldh [rLCDC], a
+	ret

home/map_objects.asm

@@ -0,0 +1,575 @@
+; Functions handling map objects.
+
+GetSpritePalette::
+	push hl
+	push de
+	push bc
+	ld c, a
+
+	farcall _GetSpritePalette
+
+	ld a, c
+	pop bc
+	pop de
+	pop hl
+	ret
+
+GetSpriteVTile::
+	push hl
+	push bc
+	ld hl, wUsedSprites + 2
+	ld c, SPRITE_GFX_LIST_CAPACITY - 1
+	ld b, a
+	ldh a, [hMapObjectIndex]
+	cp 0
+	jr z, .nope
+	ld a, b
+.loop
+	cp [hl]
+	jr z, .found
+	inc hl
+	inc hl
+	dec c
+	jr nz, .loop
+	ld a, [wUsedSprites + 1]
+	scf
+	jr .done
+
+.nope
+	ld a, [wUsedSprites + 1]
+	jr .done
+
+.found
+	inc hl
+	xor a
+	ld a, [hl]
+
+.done
+	pop bc
+	pop hl
+	ret
+
+DoesSpriteHaveFacings::
+	push de
+	push hl
+
+	ld b, a
+	ldh 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
+
+GetPlayerTile::
+	ld a, [wPlayerTile]
+	call GetTileCollision
+	ld b, a
+	ret
+
+CheckOnWater::
+	ld a, [wPlayerTile]
+	call GetTileCollision
+	sub WATER_TILE
+	ret z
+	and a
+	ret
+
+GetTileCollision::
+; Get the collision type of tile a.
+
+	push de
+	push hl
+
+	ld hl, TileCollisionTable
+	ld e, a
+	ld d, 0
+	add hl, de
+
+	ldh 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
+
+CheckGrassTile::
+	ld d, a
+	and $f0
+	cp HI_NYBBLE_TALL_GRASS
+	jr z, .check
+	cp HI_NYBBLE_WATER
+	jr nz, .nope
+.check
+	ld a, d
+	and LO_NYBBLE_GRASS
+	ret z
+.nope
+	scf
+	ret
+
+CheckSuperTallGrassTile::
+	cp COLL_LONG_GRASS
+	ret z
+	cp COLL_LONG_GRASS_1C
+	ret
+
+CheckCutTreeTile::
+	cp COLL_CUT_TREE
+	ret z
+	cp COLL_CUT_TREE_1A
+	ret
+
+CheckHeadbuttTreeTile::
+	cp COLL_HEADBUTT_TREE
+	ret z
+	cp COLL_HEADBUTT_TREE_1D
+	ret
+
+CheckCounterTile::
+	cp COLL_COUNTER
+	ret z
+	cp COLL_COUNTER_98
+	ret
+
+CheckPitTile::
+	cp COLL_PIT
+	ret z
+	cp COLL_PIT_68
+	ret
+
+CheckIceTile::
+	cp COLL_ICE
+	ret z
+	cp COLL_ICE_2B
+	ret z
+	scf
+	ret
+
+CheckWhirlpoolTile::
+	nop
+	cp COLL_WHIRLPOOL
+	ret z
+	cp COLL_WHIRLPOOL_2C
+	ret z
+	scf
+	ret
+
+CheckWaterfallTile::
+	cp COLL_WATERFALL
+	ret z
+	cp COLL_CURRENT_DOWN
+	ret
+
+CheckStandingOnEntrance::
+	ld a, [wPlayerTile]
+	cp COLL_DOOR
+	ret z
+	cp COLL_DOOR_79
+	ret z
+	cp COLL_STAIRCASE
+	ret z
+	cp COLL_CAVE
+	ret
+
+GetMapObject::
+; Return the location of map object a in bc.
+	ld hl, wMapObjects
+	ld bc, MAPOBJECT_LENGTH
+	call AddNTimes
+	ld b, h
+	ld c, l
+	ret
+
+CheckObjectVisibility::
+; Sets carry if the object is not visible on the screen.
+	ldh [hMapObjectIndex], a
+	call GetMapObject
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, bc
+	ld a, [hl]
+	cp -1
+	jr z, .not_visible
+	ldh [hObjectStructIndex], a
+	call GetObjectStruct
+	and a
+	ret
+
+.not_visible
+	scf
+	ret
+
+CheckObjectTime::
+	ld hl, MAPOBJECT_HOUR_1
+	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, .TimesOfDay
+	ld a, [wTimeOfDay]
+	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
+
+.TimesOfDay:
+; entries correspond to TimeOfDay values
+	db MORN
+	db DAY
+	db NITE
+
+.check_hour
+	ld hl, MAPOBJECT_HOUR_1
+	add hl, bc
+	ld d, [hl]
+	ld hl, MAPOBJECT_HOUR_2
+	add hl, bc
+	ld e, [hl]
+	ld hl, hHours
+	ld a, d
+	cp e
+	ret z
+	jr c, .check_timeofday
+	ld a, [hl]
+	cp d
+	ret nc
+	cp e
+	ret z
+	ccf
+	ret
+
+.check_timeofday
+	ld a, e
+	cp [hl]
+	ret c
+	ld a, [hl]
+	cp d
+	ret
+
+UnmaskCopyMapObjectStruct::
+	ldh [hMapObjectIndex], a
+	call UnmaskObject
+	ldh a, [hMapObjectIndex]
+	call GetMapObject
+	farcall CopyObjectStruct
+	ret
+
+ApplyDeletionToMapObject::
+	ldh [hMapObjectIndex], 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
+	farcall DeleteMapObject
+	ret
+
+.CheckStopFollow:
+	ld hl, wObjectFollow_Leader
+	cp [hl]
+	jr z, .ok
+	ld hl, wObjectFollow_Follower
+	cp [hl]
+	ret nz
+.ok
+	farcall StopFollow
+	ld a, -1
+	ld [wObjectFollow_Leader], a
+	ld [wObjectFollow_Follower], a
+	ret
+
+DeleteObjectStruct::
+	call ApplyDeletionToMapObject
+	jp MaskObject
+
+CopyPlayerObjectTemplate::
+	push hl
+	call GetMapObject
+	ld d, b
+	ld e, c
+	ld a, -1
+	ld [de], a
+	inc de
+	pop hl
+	ld bc, MAPOBJECT_LENGTH - 1
+	jp CopyBytes
+
+LoadMovementDataPointer::
+; Load the movement data pointer for object a.
+	ld [wMovementObject], a
+	ldh a, [hROMBank]
+	ld [wMovementDataBank], a
+	ld a, l
+	ld [wMovementDataAddress], a
+	ld a, h
+	ld [wMovementDataAddress + 1], a
+	ld a, [wMovementObject]
+	call CheckObjectVisibility
+	ret c
+
+	ld hl, OBJECT_MOVEMENT_TYPE
+	add hl, bc
+	ld [hl], SPRITEMOVEDATA_SCRIPTED
+
+	ld hl, OBJECT_STEP_TYPE
+	add hl, bc
+	ld [hl], STEP_TYPE_RESET
+
+	ld hl, wVramState
+	set 7, [hl]
+	and a
+	ret
+
+FindFirstEmptyObjectStruct::
+; 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, wObjectStructs
+	ld de, OBJECT_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
+
+GetSpriteMovementFunction::
+	ld hl, OBJECT_MOVEMENT_TYPE
+	add hl, bc
+	ld a, [hl]
+	cp NUM_SPRITEMOVEDATA
+	jr c, .ok
+	xor a
+
+.ok
+	ld hl, SpriteMovementData + SPRITEMOVEATTR_MOVEMENT
+	ld e, a
+	ld d, 0
+rept NUM_SPRITEMOVEDATA_FIELDS
+	add hl, de
+endr
+	ld a, [hl]
+	ret
+
+GetInitialFacing::
+	push bc
+	push de
+	ld e, a
+	ld d, 0
+	ld hl, SpriteMovementData + SPRITEMOVEATTR_FACING
+rept NUM_SPRITEMOVEDATA_FIELDS
+	add hl, de
+endr
+	ld a, BANK(SpriteMovementData)
+	call GetFarByte
+	add a
+	add a
+	maskbits NUM_DIRECTIONS, 2
+	pop de
+	pop bc
+	ret
+
+CopySpriteMovementData::
+	ld l, a
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(SpriteMovementData)
+	rst Bankswitch
+	ld a, l
+	push bc
+
+	call .CopyData
+
+	pop bc
+	pop af
+	rst Bankswitch
+
+	ret
+
+.CopyData:
+	ld hl, OBJECT_MOVEMENT_TYPE
+	add hl, de
+	ld [hl], a
+
+	push de
+	ld e, a
+	ld d, 0
+	ld hl, SpriteMovementData + SPRITEMOVEATTR_FACING
+rept NUM_SPRITEMOVEDATA_FIELDS
+	add hl, de
+endr
+	ld b, h
+	ld c, l
+	pop de
+
+	ld a, [bc]
+	inc bc
+	rlca
+	rlca
+	maskbits NUM_DIRECTIONS, 2
+	ld hl, OBJECT_DIRECTION
+	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
+
+_GetMovementIndex::
+; Switch to the movement data bank
+	ldh a, [hROMBank]
+	push af
+	ld a, [hli]
+	rst Bankswitch
+; Load the current script byte as given by OBJECT_MOVEMENT_INDEX, and increment OBJECT_MOVEMENT_INDEX
+	ld a, [hli]
+	ld d, [hl]
+	ld hl, OBJECT_MOVEMENT_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
+
+SetVramState_Bit0:: ; unreferenced
+	ld hl, wVramState
+	set 0, [hl]
+	ret
+
+ResetVramState_Bit0:: ; unreferenced
+	ld hl, wVramState
+	res 0, [hl]
+	ret
+
+UpdateSprites::
+	ld a, [wVramState]
+	bit 0, a
+	ret z
+
+	farcall UpdateAllObjectsFrozen
+	farcall _UpdateSprites
+	ret
+
+GetObjectStruct::
+	ld bc, OBJECT_LENGTH
+	ld hl, wObjectStructs
+	call AddNTimes
+	ld b, h
+	ld c, l
+	ret
+
+DoesObjectHaveASprite::
+	ld hl, OBJECT_SPRITE
+	add hl, bc
+	ld a, [hl]
+	and a
+	ret
+
+SetSpriteDirection::
+	; preserves other flags
+	push af
+	ld hl, OBJECT_DIRECTION
+	add hl, bc
+	ld a, [hl]
+	and %11110011
+	ld e, a
+	pop af
+	maskbits NUM_DIRECTIONS, 2
+	or e
+	ld [hl], a
+	ret
+
+GetSpriteDirection::
+	ld hl, OBJECT_DIRECTION
+	add hl, bc
+	ld a, [hl]
+	maskbits NUM_DIRECTIONS, 2
+	ret

home/math.asm

@@ -0,0 +1,58 @@
+SimpleMultiply::
+; Return a * c.
+	and a
+	ret z
+
+	push bc
+	ld b, a
+	xor a
+.loop
+	add c
+	dec b
+	jr nz, .loop
+	pop bc
+	ret
+
+SimpleDivide::
+; Divide a by c. Return quotient b and remainder a.
+	ld b, 0
+.loop
+	inc b
+	sub c
+	jr nc, .loop
+	dec b
+	add c
+	ret
+
+Multiply::
+; Multiply hMultiplicand (3 bytes) by hMultiplier. Result in hProduct.
+; All values are big endian.
+	push hl
+	push bc
+
+	callfar _Multiply
+
+	pop bc
+	pop hl
+	ret
+
+Divide::
+; Divide hDividend length b (max 4 bytes) by hDivisor. Result in hQuotient.
+; All values are big endian.
+	push hl
+	push de
+	push bc
+	homecall _Divide
+	pop bc
+	pop de
+	pop hl
+	ret
+
+SubtractAbsolute:: ; unreferenced
+; Return |a - b|, sign in carry.
+	sub b
+	ret nc
+	cpl
+	add 1
+	scf
+	ret

home/menu.asm

@@ -0,0 +1,813 @@
+Load2DMenuData::
+	push hl
+	push bc
+	ld hl, w2DMenuData
+	ld b, w2DMenuDataEnd - w2DMenuData
+.loop
+	ld a, [de]
+	inc de
+	ld [hli], a
+	dec b
+	jr nz, .loop
+
+	; Reset menu state
+	ld a, $1
+	ld [hli], a ; wMenuCursorY
+	ld [hli], a ; wMenuCursorX
+	xor a
+	ld [hli], a ; wCursorOffCharacter
+	ld [hli], a ; wCursorCurrentTile
+	ld [hli], a
+	pop bc
+	pop hl
+	ret
+
+StaticMenuJoypad::
+	callfar _StaticMenuJoypad
+	jr GetMenuJoypad
+
+ScrollingMenuJoypad::
+	callfar _ScrollingMenuJoypad
+; fallthrough
+
+GetMenuJoypad::
+	push bc
+	push af
+	ldh a, [hJoyLast]
+	and D_PAD
+	ld b, a
+	ldh a, [hJoyPressed]
+	and BUTTONS
+	or b
+	ld b, a
+	pop af
+	ld a, b
+	pop bc
+	ret
+
+PlaceHollowCursor::
+	ld hl, wCursorCurrentTile
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld [hl], "▷"
+	ret
+
+HideCursor::
+	ld hl, wCursorCurrentTile
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld [hl], " "
+	ret
+
+PushWindow::
+	callfar _PushWindow
+	ret
+
+ExitMenu::
+	push af
+	callfar _ExitMenu
+	pop af
+	ret
+
+InitVerticalMenuCursor::
+	callfar _InitVerticalMenuCursor
+	ret
+
+CloseWindow::
+	push af
+	call ExitMenu
+	call ApplyTilemap
+	call UpdateSprites
+	pop af
+	ret
+
+RestoreTileBackup::
+	call MenuBoxCoord2Tile
+	call .copy
+	call MenuBoxCoord2Attr
+
+.copy
+	call GetMenuBoxDims
+	inc b
+	inc c
+
+.row
+	push bc
+	push hl
+
+.col
+	ld a, [de]
+	ld [hli], a
+	dec de
+	dec c
+	jr nz, .col
+
+	pop hl
+	ld bc, SCREEN_WIDTH
+	add hl, bc
+	pop bc
+	dec b
+	jr nz, .row
+
+	ret
+
+PopWindow::
+	ld b, wMenuHeaderEnd - wMenuHeader
+	ld de, wMenuHeader
+.loop
+	ld a, [hld]
+	ld [de], a
+	inc de
+	dec b
+	jr nz, .loop
+	ret
+
+GetMenuBoxDims::
+	ld a, [wMenuBorderTopCoord] ; top
+	ld b, a
+	ld a, [wMenuBorderBottomCoord] ; bottom
+	sub b
+	ld b, a
+	ld a, [wMenuBorderLeftCoord] ; left
+	ld c, a
+	ld a, [wMenuBorderRightCoord] ; right
+	sub c
+	ld c, a
+	ret
+
+CopyMenuData::
+	push hl
+	push de
+	push bc
+	push af
+	ld hl, wMenuDataPointer
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld de, wMenuData
+	ld bc, wMenuDataEnd - wMenuData
+	call CopyBytes
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
+
+GetWindowStackTop::
+	ld hl, wWindowStackPointer
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	inc hl
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ret
+
+PlaceVerticalMenuItems::
+	call CopyMenuData
+	ld hl, wMenuDataPointer
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+	call GetMenuTextStartCoord
+	call Coord2Tile ; hl now contains the tilemap address where we will start printing text.
+	inc de
+	ld a, [de] ; Number of items
+	inc de
+	ld b, a
+.loop
+	push bc
+	call PlaceString
+	inc de
+	ld bc, 2 * SCREEN_WIDTH
+	add hl, bc
+	pop bc
+	dec b
+	jr nz, .loop
+
+	ld a, [wMenuDataFlags]
+	bit 4, a
+	ret z
+
+	call MenuBoxCoord2Tile
+	ld a, [de]
+	ld c, a
+	inc de
+	ld b, 0
+	add hl, bc
+	jp PlaceString
+
+MenuBox::
+	call MenuBoxCoord2Tile
+	call GetMenuBoxDims
+	dec b
+	dec c
+	jp Textbox
+
+GetMenuTextStartCoord::
+	ld a, [wMenuBorderTopCoord]
+	ld b, a
+	inc b
+	ld a, [wMenuBorderLeftCoord]
+	ld c, a
+	inc c
+; bit 6: if not set, leave extra room on top
+	ld a, [wMenuDataFlags]
+	bit 6, a
+	jr nz, .bit_6_set
+	inc b
+
+.bit_6_set
+; bit 7: if set, leave extra room on the left
+	ld a, [wMenuDataFlags]
+	bit 7, a
+	ret z
+	inc c
+	ret
+
+ClearMenuBoxInterior::
+	call MenuBoxCoord2Tile
+	ld bc, SCREEN_WIDTH + 1
+	add hl, bc
+	call GetMenuBoxDims
+	dec b
+	dec c
+	jp ClearBox
+
+ClearWholeMenuBox::
+	call MenuBoxCoord2Tile
+	call GetMenuBoxDims
+	inc c
+	inc b
+	jp ClearBox
+
+MenuBoxCoord2Tile::
+	ld a, [wMenuBorderLeftCoord]
+	ld c, a
+	ld a, [wMenuBorderTopCoord]
+	ld b, a
+	; fallthrough
+
+Coord2Tile::
+; Return the address of wTilemap(c, b) in hl.
+	xor a
+	ld h, a
+	ld l, b
+	ld a, c
+	ld b, h
+	ld c, l
+	add hl, hl
+	add hl, hl
+	add hl, bc
+	add hl, hl
+	add hl, hl
+	ld c, a
+	xor a
+	ld b, a
+	add hl, bc
+	bccoord 0, 0
+	add hl, bc
+	ret
+
+MenuBoxCoord2Attr::
+	ld a, [wMenuBorderLeftCoord]
+	ld c, a
+	ld a, [wMenuBorderTopCoord]
+	ld b, a
+	; fallthrough
+
+Coord2Attr:: ; unreferenced
+; Return the address of wAttrmap(c, b) in hl.
+	xor a
+	ld h, a
+	ld l, b
+	ld a, c
+	ld b, h
+	ld c, l
+	add hl, hl
+	add hl, hl
+	add hl, bc
+	add hl, hl
+	add hl, hl
+	ld c, a
+	xor a
+	ld b, a
+	add hl, bc
+	bccoord 0, 0, wAttrmap
+	add hl, bc
+	ret
+
+LoadMenuHeader::
+	call CopyMenuHeader
+	jp PushWindow
+
+CopyMenuHeader::
+	ld de, wMenuHeader
+	ld bc, wMenuHeaderEnd - wMenuHeader
+	call CopyBytes
+	ldh a, [hROMBank]
+	ld [wMenuDataBank], a
+	ret
+
+StoreMenuCursorPosition::
+	ld [wMenuCursorPosition], a
+	ret
+
+MenuTextbox::
+	push hl
+	call LoadMenuTextbox
+	pop hl
+	jp PrintText
+
+LoadMenuTextbox::
+	ld hl, .MenuHeader
+	jp LoadMenuHeader
+
+.MenuHeader:
+	db MENU_BACKUP_TILES ; flags
+	menu_coords 0, 12, SCREEN_WIDTH - 1, SCREEN_HEIGHT - 1
+	dw vTiles0
+	db 0 ; default option
+
+MenuTextboxBackup::
+	call MenuTextbox
+	jp CloseWindow
+
+LoadStandardMenuHeader::
+	ld hl, .MenuHeader
+	jp LoadMenuHeader
+
+.MenuHeader:
+	db MENU_BACKUP_TILES ; flags
+	menu_coords 0, 0, SCREEN_WIDTH - 1, SCREEN_HEIGHT - 1
+	dw 0
+	db 1 ; default option
+
+VerticalMenu::
+	xor a
+	ldh [hBGMapMode], a
+	call MenuBox
+	call UpdateSprites
+	call PlaceVerticalMenuItems
+	call ApplyTilemap
+	call CopyMenuData
+	ld a, [wMenuDataFlags]
+	bit 7, a
+	jr z, .cancel
+	call InitVerticalMenuCursor
+	call StaticMenuJoypad
+	call MenuClickSound
+	bit 1, a
+	jr z, .okay
+.cancel
+	scf
+	ret
+
+.okay
+	and a
+	ret
+
+GetMenu2::
+	call LoadMenuHeader
+	call VerticalMenu
+	call CloseWindow
+	ld a, [wMenuCursorY]
+	ret
+
+CopyNameFromMenu::
+	push hl
+	push bc
+	push af
+	ld hl, wMenuDataPointer
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	inc hl
+	inc hl
+	pop af
+	call GetNthString
+	ld d, h
+	ld e, l
+	call CopyName1
+	pop bc
+	pop hl
+	ret
+
+PlaceGenericTwoOptionBox:: ; unreferenced
+	call LoadMenuHeader
+	jr InterpretTwoOptionMenu
+
+YesNoBox::
+	lb bc, SCREEN_WIDTH - 6, 7
+; fallthrough
+
+PlaceYesNoBox::
+; Return nc (yes) or c (no).
+	push bc
+	ld hl, YesNoMenuHeader
+	call CopyMenuHeader
+	pop bc
+; This seems to be an overflow prevention,
+; but it was coded wrong.
+	ld a, b
+	cp SCREEN_WIDTH - 1 - 5
+	jr nz, .okay ; should this be "jr nc"?
+	ld a, SCREEN_WIDTH - 1 - 5
+	ld b, a
+
+.okay
+	ld a, b
+	ld [wMenuBorderLeftCoord], a
+	add 5
+	ld [wMenuBorderRightCoord], a
+	ld a, c
+	ld [wMenuBorderTopCoord], a
+	add 4
+	ld [wMenuBorderBottomCoord], a
+	call PushWindow
+; fallthrough
+
+InterpretTwoOptionMenu::
+	call VerticalMenu
+	push af
+	ld c, $f
+	call DelayFrames
+	call CloseWindow
+	pop af
+	jr c, .no
+	ld a, [wMenuCursorY]
+	cp 2 ; no
+	jr z, .no
+	and a
+	ret
+
+.no
+	ld a, 2
+	ld [wMenuCursorY], a
+	scf
+	ret
+
+YesNoMenuHeader::
+	db MENU_BACKUP_TILES ; flags
+	menu_coords 10, 5, 15, 9
+	dw .MenuData
+	db 1 ; default option
+
+.MenuData:
+	db STATICMENU_CURSOR | STATICMENU_NO_TOP_SPACING ; flags
+	db 2
+	db "YES@"
+	db "NO@"
+
+OffsetMenuHeader::
+	call _OffsetMenuHeader
+	jp PushWindow
+
+_OffsetMenuHeader::
+	push de
+	call CopyMenuHeader
+	pop de
+	ld a, [wMenuBorderLeftCoord]
+	ld h, a
+	ld a, [wMenuBorderRightCoord]
+	sub h
+	ld h, a
+	ld a, d
+	ld [wMenuBorderLeftCoord], a
+	add h
+	ld [wMenuBorderRightCoord], a
+	ld a, [wMenuBorderTopCoord]
+	ld l, a
+	ld a, [wMenuBorderBottomCoord]
+	sub l
+	ld l, a
+	ld a, e
+	ld [wMenuBorderTopCoord], a
+	add l
+	ld [wMenuBorderBottomCoord], a
+	ret
+
+DoNthMenu::
+	call DrawVariableLengthMenuBox
+	call MenuWriteText
+	call InitMenuCursorAndButtonPermissions
+	call GetStaticMenuJoypad
+	call GetMenuJoypad
+	jp MenuClickSound
+
+SetUpMenu::
+	call DrawVariableLengthMenuBox
+	call MenuWriteText
+	call InitMenuCursorAndButtonPermissions
+	ld hl, w2DMenuFlags1
+	set 7, [hl]
+	ret
+
+DrawVariableLengthMenuBox::
+	call CopyMenuData
+	call GetMenuIndexSet
+	call AutomaticGetMenuBottomCoord
+	jp MenuBox
+
+MenuWriteText::
+	xor a
+	ldh [hBGMapMode], a
+	call GetMenuIndexSet ; sort out the text
+	call RunMenuItemPrintingFunction ; actually write it
+	call SafeUpdateSprites
+	ldh a, [hOAMUpdate]
+	push af
+	ld a, $1
+	ldh [hOAMUpdate], a
+	call ApplyTilemap
+	pop af
+	ldh [hOAMUpdate], a
+	ret
+
+AutomaticGetMenuBottomCoord::
+	ld a, [wMenuBorderLeftCoord]
+	ld c, a
+	ld a, [wMenuBorderRightCoord]
+	sub c
+	ld c, a
+	ld a, [wMenuDataItems]
+	add a
+	inc a
+	ld b, a
+	ld a, [wMenuBorderTopCoord]
+	add b
+	ld [wMenuBorderBottomCoord], a
+	ret
+
+GetMenuIndexSet::
+	ld hl, wMenuDataIndicesPointer
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld a, [wWhichIndexSet]
+	and a
+	jr z, .skip
+	ld b, a
+	ld c, -1
+.loop
+	ld a, [hli]
+	cp c
+	jr nz, .loop
+	dec b
+	jr nz, .loop
+
+.skip
+	ld d, h
+	ld e, l
+	ld a, [hl]
+	ld [wMenuDataItems], a
+	ret
+
+RunMenuItemPrintingFunction::
+	call MenuBoxCoord2Tile
+	ld bc, 2 * SCREEN_WIDTH + 2
+	add hl, bc
+.loop
+	inc de
+	ld a, [de]
+	cp -1
+	ret z
+	ld [wMenuSelection], a
+	push de
+	push hl
+	ld d, h
+	ld e, l
+	ld hl, wMenuDataDisplayFunctionPointer
+	call ._hl_
+	pop hl
+	ld de, 2 * SCREEN_WIDTH
+	add hl, de
+	pop de
+	jr .loop
+
+._hl_
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	jp hl
+
+InitMenuCursorAndButtonPermissions::
+	call InitVerticalMenuCursor
+	ld hl, wMenuJoypadFilter
+	ld a, [wMenuDataFlags]
+	bit 3, a
+	jr z, .disallow_select
+	set START_F, [hl]
+
+.disallow_select
+	ld a, [wMenuDataFlags]
+	bit 2, a
+	ret z
+	set D_LEFT_F, [hl]
+	set D_RIGHT_F, [hl]
+	ret
+
+GetScrollingMenuJoypad::
+	call ScrollingMenuJoypad
+	ld hl, wMenuJoypadFilter
+	and [hl]
+	jr ContinueGettingMenuJoypad
+
+GetStaticMenuJoypad::
+	xor a
+	ld [wMenuJoypad], a
+	call StaticMenuJoypad
+; fallthrough
+
+ContinueGettingMenuJoypad:
+	bit A_BUTTON_F, a
+	jr nz, .a_button
+	bit B_BUTTON_F, a
+	jr nz, .b_start
+	bit START_F, a
+	jr nz, .b_start
+	bit D_RIGHT_F, a
+	jr nz, .d_right
+	bit D_LEFT_F, a
+	jr nz, .d_left
+	xor a
+	ld [wMenuJoypad], a
+	jr .done
+
+.d_right
+	ld a, D_RIGHT
+	ld [wMenuJoypad], a
+	jr .done
+
+.d_left
+	ld a, D_LEFT
+	ld [wMenuJoypad], a
+	jr .done
+
+.a_button
+	ld a, A_BUTTON
+	ld [wMenuJoypad], a
+
+.done
+	call GetMenuIndexSet
+	ld a, [wMenuCursorY]
+	ld l, a
+	ld h, 0
+	add hl, de
+	ld a, [hl]
+	ld [wMenuSelection], a
+	ld a, [wMenuCursorY]
+	ld [wMenuCursorPosition], a
+	and a
+	ret
+
+.b_start
+	ld a, B_BUTTON
+	ld [wMenuJoypad], a
+	ld a, -1
+	ld [wMenuSelection], a
+	scf
+	ret
+
+PlaceMenuStrings::
+	push de
+	ld hl, wMenuDataPointerTableAddr
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld a, [wMenuSelection]
+	call GetNthString
+	ld d, h
+	ld e, l
+	pop hl
+	jp PlaceString
+
+PlaceNthMenuStrings::
+	push de
+	ld a, [wMenuSelection]
+	call GetMenuDataPointerTableEntry
+	inc hl
+	inc hl
+	ld a, [hli]
+	ld d, [hl]
+	ld e, a
+	pop hl
+	jp PlaceString
+
+MenuJumptable::
+	ld a, [wMenuSelection]
+	call GetMenuDataPointerTableEntry
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	jp hl
+
+GetMenuDataPointerTableEntry::
+	ld e, a
+	ld d, 0
+	ld hl, wMenuDataPointerTableAddr
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	add hl, de
+	add hl, de
+	add hl, de
+	add hl, de
+	ret
+
+ClearWindowData::
+	ld hl, wMenuMetadata
+	call .ClearMenuData
+	ld hl, wMenuHeader
+	call .ClearMenuData
+	ld hl, wMenuData
+	call .ClearMenuData
+	ld hl, wMoreMenuData
+	call .ClearMenuData
+
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wWindowStack)
+	ldh [rSVBK], a
+
+	xor a
+	ld hl, wWindowStackBottom
+	ld [hld], a
+	ld [hld], a
+	ld a, l
+	ld [wWindowStackPointer], a
+	ld a, h
+	ld [wWindowStackPointer + 1], a
+
+	pop af
+	ldh [rSVBK], a
+	ret
+
+.ClearMenuData:
+	ld bc, wMenuMetadataEnd - wMenuMetadata
+	assert wMenuMetadataEnd - wMenuMetadata == wMenuHeaderEnd - wMenuHeader
+	assert wMenuMetadataEnd - wMenuMetadata == wMenuDataEnd - wMenuData
+	assert wMenuMetadataEnd - wMenuMetadata == wMoreMenuDataEnd - wMoreMenuData
+	xor a
+	jp ByteFill
+
+MenuClickSound::
+	push af
+	and A_BUTTON | B_BUTTON
+	jr z, .nosound
+	ld hl, wMenuFlags
+	bit 3, [hl]
+	jr nz, .nosound
+	call PlayClickSFX
+.nosound
+	pop af
+	ret
+
+PlayClickSFX::
+	push de
+	ld de, SFX_READ_TEXT_2
+	call PlaySFX
+	pop de
+	ret
+
+MenuTextboxWaitButton::
+	call MenuTextbox
+	call WaitButton
+	jp ExitMenu
+
+Place2DMenuItemName::
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+
+	call PlaceString
+	pop af
+	rst Bankswitch
+
+	ret
+
+_2DMenu::
+	ldh a, [hROMBank]
+	ld [wMenuData_2DMenuItemStringsBank], a
+	farcall _2DMenu_
+	ld a, [wMenuCursorPosition]
+	ret
+
+InterpretBattleMenu::
+	ldh a, [hROMBank]
+	ld [wMenuData_2DMenuItemStringsBank], a
+	farcall _InterpretBattleMenu
+	ld a, [wMenuCursorPosition]
+	ret
+
+InterpretMobileMenu:: ; unreferenced
+	ldh a, [hROMBank]
+	ld [wMenuData_2DMenuItemStringsBank], a
+	farcall _InterpretMobileMenu
+	ld a, [wMenuCursorPosition]
+	ret

home/mobile.asm

@@ -0,0 +1,255 @@
+MobileAPI::
+; Mobile
+	cp $2
+	ld [wMobileAPIIndex], a
+	ld a, l
+	ld [wc986], a
+	ld a, h
+	ld [wc987], a
+	jr nz, .okay
+
+	ld [wc982], a
+	ld a, l
+	ld [wc981], a
+	ld hl, wc983
+	ld a, c
+	ld [hli], a
+	ld a, b
+	ld [hl], a
+
+.okay
+	ld hl, wc822
+	set 6, [hl]
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_MobileAPI)
+	ld [wc981], a
+	rst Bankswitch
+
+	jp _MobileAPI
+
+ReturnMobileAPI::
+; Return from _MobileAPI
+	ld [wc986], a
+	ld a, l
+	ld [wc987], a
+	ld a, h
+	ld [wMobileAPIIndex], a
+
+	pop bc
+	ld a, b
+	ld [wc981], a
+	rst Bankswitch
+
+	ld hl, wc822
+	res 6, [hl]
+	ld hl, wc987
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld a, [wc986]
+	ret
+
+MobileReceive::
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_MobileReceive)
+	ld [wc981], a
+	rst Bankswitch
+
+	call _MobileReceive
+	pop bc
+	ld a, b
+	ld [wc981], a
+	rst Bankswitch
+
+	ret
+
+MobileTimer::
+	push af
+	push bc
+	push de
+	push hl
+
+	ldh a, [hMobile]
+	and a
+	jr z, .pop_ret
+
+	xor a
+	ldh [rTAC], a
+
+; Turn off timer interrupt
+	ldh a, [rIF]
+	and 1 << VBLANK | 1 << LCD_STAT | 1 << SERIAL | 1 << JOYPAD
+	ldh [rIF], a
+
+	ld a, [wc86a]
+	or a
+	jr z, .pop_ret
+
+	ld a, [wc822]
+	bit 1, a
+	jr nz, .skip_timer
+
+	ldh a, [rSC]
+	and 1 << rSC_ON
+	jr nz, .skip_timer
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_Timer)
+	ld [wc981], a
+	rst Bankswitch
+
+	call _Timer
+
+	pop bc
+	ld a, b
+	ld [wc981], a
+	rst Bankswitch
+
+.skip_timer
+	ldh a, [rTMA]
+	ldh [rTIMA], a
+
+	ld a, 1 << rTAC_ON | rTAC_65536_HZ
+	ldh [rTAC], a
+
+.pop_ret
+	pop hl
+	pop de
+	pop bc
+	pop af
+	reti
+
+Function3eea::
+	push hl
+	push bc
+	ld de, wAttrmap - wTilemap
+	add hl, de
+	inc b
+	inc b
+	inc c
+	inc c
+	call Function3f35
+	pop bc
+	pop hl
+	jp MobileHome_PlaceBox
+
+Function3f20::
+	hlcoord 0, 0, wAttrmap
+	ld b,  6
+	ld c, 20
+	call Function3f35
+	hlcoord 0, 0
+	ld b,  4
+	ld c, 18
+	jp MobileHome_PlaceBox
+
+Function3f35::
+	ld a, 6
+	ld de, SCREEN_WIDTH
+.row
+	push bc
+	push hl
+.col
+	ld [hli], a
+	dec c
+	jr nz, .col
+	pop hl
+	add hl, de
+	pop bc
+	dec b
+	jr nz, .row
+	ret
+
+MobileHome_PlaceBox:
+	push bc
+	call .FillTop
+	pop bc
+.RowLoop:
+	push bc
+	call .FillMiddle
+	pop bc
+	dec b
+	jr nz, .RowLoop
+	call .FillBottom
+	ret
+
+.FillTop:
+	ld a, $63
+	ld d, $62
+	ld e, $64
+	jr .FillRow
+
+.FillBottom:
+	ld a, $68
+	ld d, $67
+	ld e, $69
+	jr .FillRow
+
+.FillMiddle:
+	ld a, $7f
+	ld d, $65
+	ld e, $66
+
+.FillRow:
+	push hl
+	ld [hl], d
+	inc hl
+.FillLoop:
+	ld [hli], a
+	dec c
+	jr nz, .FillLoop
+	ld [hl], e
+	pop hl
+	ld de, SCREEN_WIDTH
+	add hl, de
+	ret
+
+Function3f7c::
+	call MenuBoxCoord2Tile
+	call GetMenuBoxDims
+	dec b
+	dec c
+	jp Function3eea
+
+Function3f88::
+	ld hl, wDecompressScratch
+	ld b, 0
+.row
+	push bc
+	ld c, 1 tiles / 2
+.col
+	ld a, [de]
+	inc de
+	cpl
+	ld [hl], 0
+	inc hl
+	ld [hli], a
+	dec c
+	jr nz, .col
+	pop bc
+	dec c
+	jr nz, .row
+	ret
+
+Function3f9f::
+	ld hl, wDecompressScratch
+.row
+	push bc
+	ld c, 1 tiles / 2
+.col
+	ld a, [de]
+	inc de
+	inc de
+	cpl
+	ld [hl], $0
+	inc hl
+	ld [hli], a
+	dec c
+	jr nz, .col
+	pop bc
+	dec c
+	jr nz, .row
+	ret

home/movement.asm

@@ -0,0 +1,128 @@
+InitMovementBuffer::
+	ld [wMovementBufferObject], a
+	xor a
+	ld [wMovementBufferCount], a
+	ld [wUnusedMovementBufferBank], a
+	ld a, LOW(wMovementBuffer)
+	ld [wUnusedMovementBufferPointer], a
+	ld a, HIGH(wMovementBuffer)
+	ld [wUnusedMovementBufferPointer + 1], a
+	ret
+
+DecrementMovementBufferCount::
+	ld a, [wMovementBufferCount]
+	and a
+	ret z
+	dec a
+	ld [wMovementBufferCount], a
+	ret
+
+AppendToMovementBuffer::
+	push hl
+	push de
+	ld hl, wMovementBufferCount
+	ld e, [hl]
+	inc [hl]
+	ld d, 0
+	ld hl, wMovementBuffer
+	add hl, de
+	ld [hl], a
+	pop de
+	pop hl
+	ret
+
+AppendToMovementBufferNTimes::
+	push af
+	ld a, c
+	and a
+	jr nz, .okay
+	pop af
+	ret
+
+.okay
+	pop af
+.loop
+	call AppendToMovementBuffer
+	dec c
+	jr nz, .loop
+	ret
+
+ComputePathToWalkToPlayer::
+	push af
+; compare x coords, load left/right into h, and x distance into d
+	ld a, b
+	sub d
+	ld h, LEFT
+	jr nc, .got_x_distance
+	dec a
+	cpl
+	ld h, RIGHT
+
+.got_x_distance
+	ld d, a
+; compare y coords, load up/down into l, and y distance into e
+	ld a, c
+	sub e
+	ld l, UP
+	jr nc, .got_y_distance
+	dec a
+	cpl
+	ld l, DOWN
+
+.got_y_distance
+	ld e, a
+; if the x distance is less than the y distance, swap h and l, and swap d and e
+	cp d
+	jr nc, .done
+	ld a, h
+	ld h, l
+	ld l, a
+	ld a, d
+	ld d, e
+	ld e, a
+
+.done
+	pop af
+	ld b, a
+; Add movement in the longer direction first...
+	ld a, h
+	call .GetMovementData
+	ld c, d
+	call AppendToMovementBufferNTimes
+; ... then add the shorter direction.
+	ld a, l
+	call .GetMovementData
+	ld c, e
+	call AppendToMovementBufferNTimes
+	ret
+
+.GetMovementData:
+	push de
+	push hl
+	ld l, b
+	ld h, 0
+	add hl, hl
+	add hl, hl
+	ld e, a
+	ld d, 0
+	add hl, de
+	ld de, .MovementData
+	add hl, de
+	ld a, [hl]
+	pop hl
+	pop de
+	ret
+
+.MovementData:
+	slow_step DOWN
+	slow_step UP
+	slow_step LEFT
+	slow_step RIGHT
+	step DOWN
+	step UP
+	step LEFT
+	step RIGHT
+	big_step DOWN
+	big_step UP
+	big_step LEFT
+	big_step RIGHT

home/moves.asm

@@ -0,0 +1,36 @@
+GetMoveAttribute::
+; Return attribute a of move l in a; clobbers hl.
+; Replaces the old GetMoveAttr (renamed to avoid confusion).
+	sub 1
+	push bc
+	ld c, a
+	ld a, l
+	jr c, .done
+	call GetMoveAddress
+	ld b, 0
+	add hl, bc
+	call GetFarByte
+.done
+	pop bc
+	ret
+
+GetMoveAddress::
+; Get the far address for move a's attributes in a:hl.
+; This structure will not contain the animation byte! All MOVE_* constants must be reduced by 1 when indexing.
+	push bc
+	call GetMoveIndexFromID
+	ld b, h
+	ld c, l
+	ld hl, Moves
+	ld a, BANK(Moves)
+	call LoadIndirectPointer
+	pop bc
+	ret
+
+GetMoveData::
+; Copy move struct a to de.
+	ld [de], a
+	inc de
+	call GetMoveAddress
+	ld bc, MOVE_LENGTH - 1
+	jp FarCopyBytes

home/names.asm

@@ -0,0 +1,284 @@
+NamesPointers::
+; entries correspond to GetName constants (see constants/text_constants.asm); MON_NAME and MOVE_NAME are not handled by this table
+	dba ItemNames           ; ITEM_NAME
+	dbw 0, wPartyMonOTs     ; PARTY_OT_NAME
+	dbw 0, wOTPartyMonOTs   ; ENEMY_OT_NAME
+	dba TrainerClassNames   ; TRAINER_NAME
+
+GetName::
+; Return name wCurSpecies from name list wNamedObjectType in wStringBuffer1.
+
+	ldh a, [hROMBank]
+	push af
+	push hl
+	push bc
+	push de
+
+	ld a, [wCurSpecies]
+	ld [wNamedObjectIndex], a
+
+	ld a, [wNamedObjectType]
+	dec a ; MON_NAME
+	ld hl, GetPokemonName
+	jr z, .go
+	dec a ; MOVE_NAME
+	ld hl, GetMoveName
+	jr z, .go
+	dec a
+	ld hl, .generic_function
+.go
+	call _hl_
+
+	pop de
+	pop bc
+	pop hl
+	pop af
+	rst Bankswitch
+	ret
+
+.generic_function
+	ld l, a
+	add a, a
+	add a, l
+	add a, LOW(NamesPointers)
+	ld l, a
+	ld a, HIGH(NamesPointers)
+	adc 0
+	ld h, a
+	ld a, [hli]
+	rst Bankswitch
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+	ld a, [wCurSpecies]
+	dec a
+	call GetNthString
+
+	ld de, wStringBuffer1
+	ld bc, ITEM_NAME_LENGTH
+	jp CopyBytes
+
+GetNthString16::
+; Like GetNthString, but with a 16-bit index in bc
+	inc b
+	jr .handle_loop
+
+.loop
+	xor a
+	call GetNthString.loop ; will act as a = $100
+.handle_loop
+	dec b
+	jr nz, .loop
+	ld a, c
+	; fallthrough
+
+GetNthString::
+; Return the address of the
+; ath string starting from hl.
+
+	and a
+	ret z
+
+.loop
+	push bc
+	ld b, a
+	ld c, "@"
+.readChar
+	ld a, [hli]
+	cp c
+	jr nz, .readChar
+	dec b
+	jr nz, .readChar
+	pop bc
+	ret
+
+GetBasePokemonName::
+; Discards gender (Nidoran).
+
+	push hl
+	call GetPokemonName
+
+	ld hl, wStringBuffer1
+.loop
+	ld a, [hl]
+	cp "@"
+	jr z, .quit
+	cp "♂"
+	jr z, .end
+	cp "♀"
+	jr z, .end
+	inc hl
+	jr .loop
+.end
+	ld [hl], "@"
+.quit
+	pop hl
+	ret
+
+GetPokemonName::
+; Get Pokemon name for wNamedObjectIndex.
+
+	ldh a, [hROMBank]
+	push af
+	push hl
+	ld a, BANK(PokemonNames)
+	rst Bankswitch
+
+; Each name is ten characters
+	ld a, [wNamedObjectIndex]
+	call GetPokemonIndexFromID
+	ld e, l
+	ld d, h
+	add hl, hl
+	add hl, hl
+	add hl, de
+	add hl, hl
+	ld de, PokemonNames - 10
+	add hl, de
+
+; Terminator
+	ld de, wStringBuffer1
+	push de
+	ld bc, MON_NAME_LENGTH - 1
+	call CopyBytes
+	ld hl, wStringBuffer1 + MON_NAME_LENGTH - 1
+	ld [hl], "@"
+	pop de
+
+	pop hl
+	pop af
+	rst Bankswitch
+	ret
+
+GetItemName::
+; Get item name for wNamedObjectIndex.
+
+	push hl
+	push bc
+	ld a, [wNamedObjectIndex]
+
+	cp TM01
+	jr nc, .TM
+
+	ld [wCurSpecies], a
+	ld a, ITEM_NAME
+	ld [wNamedObjectType], a
+	call GetName
+	jr .Copied
+.TM:
+	call GetTMHMName
+.Copied:
+	ld de, wStringBuffer1
+	pop bc
+	pop hl
+	ret
+
+GetTMHMName::
+; Get TM/HM name for item wNamedObjectIndex.
+
+	push hl
+	push de
+	push bc
+	ld a, [wNamedObjectIndex]
+	push af
+
+; TM/HM prefix
+	cp HM01
+	push af
+	jr c, .TM
+
+	ld hl, .HMText
+	ld bc, .HMTextEnd - .HMText
+	jr .copy
+
+.TM:
+	ld hl, .TMText
+	ld bc, .TMTextEnd - .TMText
+
+.copy
+	ld de, wStringBuffer1
+	call CopyBytes
+
+; TM/HM number
+	push de
+	ld a, [wNamedObjectIndex]
+	ld c, a
+	callfar GetTMHMNumber
+	pop de
+
+; HM numbers start from 51, not 1
+	pop af
+	ld a, c
+	jr c, .not_hm
+	sub NUM_TMS
+.not_hm
+
+; Divide and mod by 10 to get the top and bottom digits respectively
+	ld b, "0"
+.mod10
+	sub 10
+	jr c, .done_mod
+	inc b
+	jr .mod10
+
+.done_mod
+	add 10
+	push af
+	ld a, b
+	ld [de], a
+	inc de
+	pop af
+
+	ld b, "0"
+	add b
+	ld [de], a
+
+; End the string
+	inc de
+	ld a, "@"
+	ld [de], a
+
+	pop af
+	ld [wNamedObjectIndex], a
+	pop bc
+	pop de
+	pop hl
+	ret
+
+.TMText:
+	db "TM"
+.TMTextEnd:
+	db "@"
+
+.HMText:
+	db "HM"
+.HMTextEnd:
+	db "@"
+
+INCLUDE "home/hm_moves.asm"
+
+GetMoveName::
+	push hl
+	push bc
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(MoveNames)
+	rst Bankswitch
+	ld a, [wNamedObjectIndex]
+	call GetMoveIndexFromID
+	dec hl
+	ld b, h
+	ld c, l
+	ld hl, MoveNames
+	call GetNthString16
+	ld de, wStringBuffer1
+	push de
+	ld bc, MOVE_NAME_LENGTH
+	call CopyBytes
+	pop de
+	pop af
+	rst Bankswitch
+	pop bc
+	pop hl
+	ret

home/palettes.asm

@@ -0,0 +1,329 @@
+; Functions dealing with palettes.
+
+UpdatePalsIfCGB::
+; update bgp data from wBGPals2
+; update obp data from wOBPals2
+; return carry if successful
+
+; check cgb
+	ldh a, [hCGB]
+	and a
+	ret z
+
+UpdateCGBPals::
+; return carry if successful
+; any pals to update?
+	ldh a, [hCGBPalUpdate]
+	and a
+	ret z
+	; fallthrough
+
+ForceUpdateCGBPals::
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wBGPals2)
+	ldh [rSVBK], a
+
+	ld hl, wBGPals2
+
+; copy 8 pals to bgpd
+	ld a, 1 << rBGPI_AUTO_INCREMENT
+	ldh [rBGPI], a
+	ld c, LOW(rBGPD)
+	ld b, 8 / 2
+.bgp
+rept (1 palettes) * 2
+	ld a, [hli]
+	ldh [c], a
+endr
+
+	dec b
+	jr nz, .bgp
+
+; hl is now wOBPals2
+
+; copy 8 pals to obpd
+	ld a, 1 << rOBPI_AUTO_INCREMENT
+	ldh [rOBPI], a
+	ld c, LOW(rOBPD)
+	ld b, 8 / 2
+.obp
+rept (1 palettes) * 2
+	ld a, [hli]
+	ldh [c], a
+endr
+
+	dec b
+	jr nz, .obp
+
+	pop af
+	ldh [rSVBK], a
+
+; clear pal update queue
+	xor a
+	ldh [hCGBPalUpdate], a
+
+	scf
+	ret
+
+DmgToCgbBGPals::
+; exists to forego reinserting cgb-converted image data
+
+; input: a -> bgp
+
+	ldh [rBGP], a
+	push af
+
+; Don't need to be here if DMG
+	ldh a, [hCGB]
+	and a
+	jr z, .end
+
+	push hl
+	push de
+	push bc
+
+	ldh a, [rSVBK]
+	push af
+
+	ld a, BANK(wBGPals2)
+	ldh [rSVBK], a
+
+; copy & reorder bg pal buffer
+	ld hl, wBGPals2 ; to
+	ld de, wBGPals1 ; from
+; order
+	ldh a, [rBGP]
+	ld b, a
+; all pals
+	ld c, 8
+	call CopyPals
+; request pal update
+	ld a, TRUE
+	ldh [hCGBPalUpdate], a
+
+	pop af
+	ldh [rSVBK], a
+
+	pop bc
+	pop de
+	pop hl
+.end
+	pop af
+	ret
+
+DmgToCgbObjPals::
+; exists to forego reinserting cgb-converted image data
+
+; input: d -> obp1
+;        e -> obp2
+
+	ld a, e
+	ldh [rOBP0], a
+	ld a, d
+	ldh [rOBP1], a
+
+	ldh a, [hCGB]
+	and a
+	ret z
+
+	push hl
+	push de
+	push bc
+
+	ldh a, [rSVBK]
+	push af
+
+	ld a, BANK(wOBPals2)
+	ldh [rSVBK], a
+
+; copy & reorder obj pal buffer
+	ld hl, wOBPals2 ; to
+	ld de, wOBPals1 ; from
+; order
+	ldh a, [rOBP0]
+	ld b, a
+; all pals
+	ld c, 8
+	call CopyPals
+; request pal update
+	ld a, TRUE
+	ldh [hCGBPalUpdate], a
+
+	pop af
+	ldh [rSVBK], a
+
+	pop bc
+	pop de
+	pop hl
+	ret
+
+DmgToCgbObjPal0::
+	ldh [rOBP0], a
+	push af
+
+; Don't need to be here if not CGB
+	ldh a, [hCGB]
+	and a
+	jr z, .dmg
+
+	push hl
+	push de
+	push bc
+
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wOBPals2)
+	ldh [rSVBK], a
+
+	ld hl, wOBPals2 palette 0
+	ld de, wOBPals1 palette 0
+	ldh a, [rOBP0]
+	ld b, a
+	ld c, 1
+	call CopyPals
+	ld a, TRUE
+	ldh [hCGBPalUpdate], a
+
+	pop af
+	ldh [rSVBK], a
+
+	pop bc
+	pop de
+	pop hl
+
+.dmg
+	pop af
+	ret
+
+DmgToCgbObjPal1::
+	ldh [rOBP1], a
+	push af
+
+	ldh a, [hCGB]
+	and a
+	jr z, .dmg
+
+	push hl
+	push de
+	push bc
+
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wOBPals2)
+	ldh [rSVBK], a
+
+	ld hl, wOBPals2 palette 1
+	ld de, wOBPals1 palette 1
+	ldh a, [rOBP1]
+	ld b, a
+	ld c, 1
+	call CopyPals
+	ld a, TRUE
+	ldh [hCGBPalUpdate], a
+
+	pop af
+	ldh [rSVBK], a
+
+	pop bc
+	pop de
+	pop hl
+
+.dmg
+	pop af
+	ret
+
+CopyPals::
+; copy c palettes in order b from de to hl
+
+	push bc
+	ld c, NUM_PAL_COLORS
+.loop
+	push de
+	push hl
+
+; get pal color
+	ld a, b
+	maskbits 1 << PAL_COLOR_SIZE
+; 2 bytes per color
+	add a
+	ld l, a
+	ld h, 0
+	add hl, de
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+
+; dest
+	pop hl
+; write color
+	ld [hl], e
+	inc hl
+	ld [hl], d
+	inc hl
+; next pal color
+rept PAL_COLOR_SIZE
+	srl b
+endr
+; source
+	pop de
+; done pal?
+	dec c
+	jr nz, .loop
+
+; de += 8 (next pal)
+	ld a, PALETTE_SIZE
+	add e
+	jr nc, .ok
+	inc d
+.ok
+	ld e, a
+
+; how many more pals?
+	pop bc
+	dec c
+	jr nz, CopyPals
+	ret
+
+ClearVBank1::
+	ldh a, [hCGB]
+	and a
+	ret z
+
+	ld a, 1
+	ldh [rVBK], a
+
+	ld hl, VRAM_Begin
+	ld bc, VRAM_End - VRAM_Begin
+	xor a
+	call ByteFill
+
+	xor a
+	ldh [rVBK], a
+	ret
+
+ReloadSpritesNoPalettes::
+	ldh a, [hCGB]
+	and a
+	ret z
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wBGPals2)
+	ldh [rSVBK], a
+	ld hl, wBGPals2
+	ld bc, (8 palettes) + (2 palettes)
+	xor a
+	call ByteFill
+	pop af
+	ldh [rSVBK], a
+	ld a, TRUE
+	ldh [hCGBPalUpdate], a
+	jp DelayFrame
+
+SwapTextboxPalettes::
+	homecall _SwapTextboxPalettes
+	ret
+
+ScrollBGMapPalettes::
+	homecall _ScrollBGMapPalettes
+	ret

home/pokedex_flags.asm

@@ -0,0 +1,110 @@
+CountSetBits::
+; Count the number of set bits in b bytes starting from hl.
+; Return in a, c and [wNumSetBits].
+	ld c, 0
+.next
+	ld a, [hli]
+	ld e, a
+	ld d, 8
+
+.count
+	srl e
+	ld a, 0
+	adc c
+	ld c, a
+	dec d
+	jr nz, .count
+
+	dec b
+	jr nz, .next
+
+	ld a, c
+	ld [wNumSetBits], a
+	ret
+
+CountSetBits16::
+; Count the number of set bits in bc bytes starting from hl - assumes bc < $1000
+; Returns in bc; hl points to the end of the buffer; clobbers everything else
+; Assumes that CountSetBits will leave hl pointing to the end of the buffer
+	swap b
+	ld a, c
+	swap a
+	and $f
+	or b
+	ld d, a
+	ld a, c
+	jr z, .small_count
+	ld bc, 0
+	and $f
+	jr z, .loop
+	push de
+	call .small_count
+	pop de
+.loop
+	push bc
+	push de
+	ld b, $10
+	call CountSetBits
+	pop de
+	pop bc
+	add a, c
+	ld c, a
+	jr nc, .handle_loop
+	inc b
+.handle_loop
+	dec d
+	jr nz, .loop
+	ret
+
+.small_count
+	ld b, a
+	call CountSetBits
+	ld b, 0
+	ret
+
+GetWeekday::
+	ld a, [wCurDay]
+.mod
+	sub 7
+	jr nc, .mod
+	add 7
+	ret
+
+SetSeenAndCaughtMon::
+	call GetPokemonFlagIndex
+	push de
+	call SetSeenMonIndex
+	pop de
+SetCaughtMonIndex::
+	ld hl, wPokedexCaught
+	jr SetPokedexStatusMonIndex
+
+SetSeenMon::
+	call GetPokemonFlagIndex
+SetSeenMonIndex::
+	ld hl, wPokedexSeen
+SetPokedexStatusMonIndex:
+	ld b, SET_FLAG
+	jr FlagActionBaseOne
+
+CheckCaughtMon::
+	call GetPokemonFlagIndex
+CheckCaughtMonIndex::
+	ld hl, wPokedexCaught
+	jr CheckPokedexStatusMonIndex
+
+CheckSeenMon::
+	call GetPokemonFlagIndex
+CheckSeenMonIndex::
+	ld hl, wPokedexSeen
+CheckPokedexStatusMonIndex:
+	ld b, CHECK_FLAG
+FlagActionBaseOne:
+	dec de
+	jp FlagAction
+
+GetPokemonFlagIndex:
+	call GetPokemonIndexFromID
+	ld d, h
+	ld e, l
+	ret

home/pokemon.asm

@@ -0,0 +1,318 @@
+IsAPokemon::
+; Return carry if species a is not a Pokemon.
+	and a
+	jr z, .NotAPokemon
+	cp EGG
+	jr z, .Pokemon
+	cp MON_TABLE_ENTRIES + 1
+	jr c, .Pokemon
+
+.NotAPokemon:
+	scf
+	ret
+
+.Pokemon:
+	and a
+	ret
+
+DrawBattleHPBar::
+; Draw an HP bar d tiles long at hl
+; Fill it up to e pixels
+
+	push hl
+	push de
+	push bc
+
+; Place 'HP:'
+	ld a, $60
+	ld [hli], a
+	ld a, $61
+	ld [hli], a
+
+; Draw a template
+	push hl
+	ld a, $62 ; empty bar
+.template
+	ld [hli], a
+	dec d
+	jr nz, .template
+	ld a, $6b ; bar end
+	add b
+	ld [hl], a
+	pop hl
+
+; Safety check # pixels
+	ld a, e
+	and a
+	jr nz, .fill
+	ld a, c
+	and a
+	jr z, .done
+	ld e, 1
+
+.fill
+; Keep drawing tiles until pixel length is reached
+	ld a, e
+	sub TILE_WIDTH
+	jr c, .lastbar
+
+	ld e, a
+	ld a, $6a ; full bar
+	ld [hli], a
+	ld a, e
+	and a
+	jr z, .done
+	jr .fill
+
+.lastbar
+	ld a, $62  ; empty bar
+	add e      ; + e
+	ld [hl], a
+
+.done
+	pop bc
+	pop de
+	pop hl
+	ret
+
+PrepMonFrontpic::
+	ld a, $1
+	ld [wBoxAlignment], a
+
+_PrepMonFrontpic::
+	ld a, [wCurPartySpecies]
+	call IsAPokemon
+	jr c, .not_pokemon
+
+	push hl
+	ld de, vTiles2
+	predef GetMonFrontpic
+	pop hl
+	xor a
+	ldh [hGraphicStartTile], a
+	lb bc, 7, 7
+	predef PlaceGraphic
+	xor a
+	ld [wBoxAlignment], a
+	ret
+
+.not_pokemon
+	xor a
+	ld [wBoxAlignment], a
+	inc a
+	ld [wCurPartySpecies], a
+	ret
+
+PlayStereoCry::
+	push af
+	ld a, 1
+	ld [wStereoPanningMask], a
+	pop af
+	call _PlayMonCry
+	call WaitSFX
+	ret
+
+PlayStereoCry2::
+; Don't wait for the cry to end.
+; Used during pic animations.
+	push af
+	ld a, 1
+	ld [wStereoPanningMask], a
+	pop af
+	jp _PlayMonCry
+
+PlayMonCry::
+	call PlayMonCry2
+	call WaitSFX
+	ret
+
+PlayMonCry2::
+; Don't wait for the cry to end.
+	push af
+	xor a
+	ld [wStereoPanningMask], a
+	ld [wCryTracks], a
+	pop af
+	call _PlayMonCry
+	ret
+
+_PlayMonCry::
+	push hl
+	push de
+	push bc
+
+	call GetCryIndex
+	jr c, .done
+
+	ld e, c
+	ld d, b
+	call PlayCry
+
+.done
+	pop bc
+	pop de
+	pop hl
+	ret
+
+LoadCry::
+	call GetCryIndex
+	ret c
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(PokemonCries)
+	rst Bankswitch
+
+	ld hl, PokemonCries
+rept MON_CRY_LENGTH
+	add hl, bc
+endr
+
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+	inc hl
+
+	ld a, [hli]
+	ld [wCryPitch], a
+	ld a, [hli]
+	ld [wCryPitch + 1], a
+	ld a, [hli]
+	ld [wCryLength], a
+	ld a, [hl]
+	ld [wCryLength + 1], a
+
+	pop af
+	rst Bankswitch
+	and a
+	ret
+
+GetCryIndex::
+	and a
+	jr z, .no
+	cp MON_TABLE_ENTRIES + 1
+	jr nc, .no
+
+	push hl
+	call GetPokemonIndexFromID
+	dec hl
+	ld b, h
+	ld c, l
+	pop hl
+	and a
+	ret
+
+.no
+	scf
+	ret
+
+PrintLevel::
+; Print wTempMonLevel at hl
+
+	ld a, [wTempMonLevel]
+	ld [hl], "<LV>"
+	inc hl
+
+; How many digits?
+	ld c, 2
+	cp 100 ; This is distinct from MAX_LEVEL.
+	jr c, Print8BitNumLeftAlign
+
+; 3-digit numbers overwrite the :L.
+	dec hl
+	inc c
+	jr Print8BitNumLeftAlign
+
+PrintLevel_Force3Digits::
+; Print :L and all 3 digits
+	ld [hl], "<LV>"
+	inc hl
+	ld c, 3
+
+Print8BitNumLeftAlign::
+	ld [wTextDecimalByte], a
+	ld de, wTextDecimalByte
+	ld b, PRINTNUM_LEFTALIGN | 1
+	jp PrintNum
+
+GetBaseData::
+	push bc
+	push de
+	push hl
+	ldh a, [hROMBank]
+	push af
+
+; Egg doesn't have BaseData
+	ld a, [wCurSpecies]
+	cp EGG
+	jr z, .egg
+
+; Get BaseData
+	call GetPokemonIndexFromID
+	ld b, h
+	ld c, l
+	ld a, BANK(BaseData)
+	ld hl, BaseData
+	call LoadIndirectPointer
+	; jr z, <some error handler>
+	rst Bankswitch
+	ld de, wCurBaseData
+	ld bc, BASE_DATA_SIZE
+	call CopyBytes
+	jr .end
+
+.egg
+	ld de, UnusedEggPic
+
+; Sprite dimensions
+	ld b, $55 ; 5x5
+	ld hl, wBasePicSize
+	ld [hl], b
+
+; Beta front and back sprites
+; (see pokegold-spaceworld's data/pokemon/base_stats/*)
+	ld hl, wBaseUnusedFrontpic
+	ld [hl], e
+	inc hl
+	ld [hl], d
+	inc hl
+	ld [hl], e
+	inc hl
+	ld [hl], d
+	jr .end ; useless
+
+.end
+; Replace Pokedex # with species
+	ld a, [wCurSpecies]
+	ld [wBaseSpecies], a
+
+	pop af
+	rst Bankswitch
+	pop hl
+	pop de
+	pop bc
+	ret
+
+GetCurNickname::
+	ld a, [wCurPartyMon]
+	ld hl, wPartyMonNicknames
+
+GetNickname::
+; Get nickname a from list hl.
+
+	push hl
+	push bc
+
+	call SkipNames
+	ld de, wStringBuffer1
+
+	push de
+	ld bc, MON_NAME_LENGTH
+	call CopyBytes
+	pop de
+
+	callfar CorrectNickErrors
+
+	pop bc
+	pop hl
+	ret

home/predef.asm

@@ -0,0 +1,52 @@
+Predef::
+; Call predefined function a.
+; Preserves bc, de, hl and f.
+
+	ld [wPredefID], a
+	ldh a, [hROMBank]
+	push af
+
+	ld a, BANK(GetPredefPointer)
+	rst Bankswitch
+	call GetPredefPointer ; stores hl in wPredefHL
+
+; Switch to the new function's bank
+	rst Bankswitch
+
+; Instead of directly calling stuff,
+; push it to the stack in reverse.
+
+	ld hl, .Return
+	push hl
+
+; Call the Predef function
+	ld a, [wPredefAddress]
+	ld h, a
+	ld a, [wPredefAddress + 1]
+	ld l, a
+	push hl
+
+; Get hl back
+	ld a, [wPredefHL]
+	ld h, a
+	ld a, [wPredefHL + 1]
+	ld l, a
+	ret
+
+.Return:
+; Clean up after the Predef call
+
+	ld a, h
+	ld [wPredefHL], a
+	ld a, l
+	ld [wPredefHL + 1], a
+
+	pop hl
+	ld a, h
+	rst Bankswitch
+
+	ld a, [wPredefHL]
+	ld h, a
+	ld a, [wPredefHL + 1]
+	ld l, a
+	ret

home/print_bcd.asm

@@ -0,0 +1,79 @@
+PrintBCDNumber::
+; function to print a BCD (Binary-coded decimal) number
+; de = address of BCD number
+; hl = destination address
+; c = flags and length
+; bit 7: if set, do not print leading zeroes
+;        if unset, print leading zeroes
+; bit 6: if set, left-align the string (do not pad empty digits with spaces)
+;        if unset, right-align the string
+; bit 5: if set, print currency symbol at the beginning of the string
+;        if unset, do not print the currency symbol
+; bits 0-4: length of BCD number in bytes
+; Note that bits 5 and 7 are modified during execution. The above reflects
+; their meaning at the beginning of the functions's execution.
+	ld b, c ; save flags in b
+	res PRINTNUM_LEADINGZEROS_F, c
+	res PRINTNUM_LEFTALIGN_F, c
+	res PRINTNUM_MONEY_F, c ; c now holds the length
+	bit PRINTNUM_MONEY_F, b
+	jr z, .loop
+	bit PRINTNUM_LEADINGZEROS_F, b
+	jr nz, .loop ; skip currency symbol
+	ld [hl], "¥"
+	inc hl
+.loop
+	ld a, [de]
+	swap a
+	call PrintBCDDigit ; print upper digit
+	ld a, [de]
+	call PrintBCDDigit ; print lower digit
+	inc de
+	dec c
+	jr nz, .loop
+	bit PRINTNUM_LEADINGZEROS_F, b
+	ret z ; if so, we are done
+; every digit of the BCD number is zero
+	bit PRINTNUM_LEFTALIGN_F, b
+	jr nz, .skipLeftAlignmentAdjustment
+; the string is left-aligned; it needs to be moved back one space
+	dec hl
+.skipLeftAlignmentAdjustment
+	bit PRINTNUM_MONEY_F, b
+	jr z, .skipCurrencySymbol
+	ld [hl], "¥" ; currency symbol
+	inc hl
+.skipCurrencySymbol
+	ld [hl], "0"
+	call PrintLetterDelay
+	inc hl
+	ret
+
+PrintBCDDigit::
+	and %00001111
+	and a
+	jr z, .zeroDigit
+; nonzero digit
+	bit PRINTNUM_LEADINGZEROS_F, b ; have any non-space characters been printed?
+	jr z, .outputDigit
+; if bit 7 is set, then no numbers have been printed yet
+	bit PRINTNUM_MONEY_F, b
+	jr z, .skipCurrencySymbol
+	ld [hl], "¥"
+	inc hl
+	res PRINTNUM_MONEY_F, b
+.skipCurrencySymbol
+	res PRINTNUM_LEADINGZEROS_F, b ; unset 7 to indicate that a nonzero digit has been reached
+.outputDigit
+	add "0"
+	ld [hli], a
+	jp PrintLetterDelay
+
+.zeroDigit
+	bit PRINTNUM_LEADINGZEROS_F, b ; either printing leading zeroes or already reached a nonzero digit?
+	jr z, .outputDigit ; if so, print a zero digit
+	bit PRINTNUM_LEFTALIGN_F, b
+	ret nz
+	ld a, " "
+	ld [hli], a ; if right-aligned, "print" a space by advancing the pointer
+	ret

home/print_text.asm

@@ -0,0 +1,127 @@
+PrintLetterDelay::
+; Wait before printing the next letter.
+
+; The text speed setting in wOptions is actually a frame count:
+; 	fast: 1 frame
+; 	mid:  3 frames
+; 	slow: 5 frames
+
+; wTextboxFlags[!0] and A or B override text speed with a one-frame delay.
+; wOptions[4] and wTextboxFlags[!1] disable the delay.
+
+	ld a, [wOptions]
+	bit NO_TEXT_SCROLL, a
+	ret nz
+
+; non-scrolling text?
+	ld a, [wTextboxFlags]
+	bit NO_TEXT_DELAY_F, a
+	ret z
+
+	push hl
+	push de
+	push bc
+
+; force fast scroll?
+	ld a, [wTextboxFlags]
+	bit FAST_TEXT_DELAY_F, a
+	jr z, .fast
+
+; text speed
+	ld a, [wOptions]
+	and %111
+	jr .updatedelay
+
+.fast
+	ld a, TEXT_DELAY_FAST
+
+.updatedelay
+	ld [wTextDelayFrames], a
+
+.checkjoypad
+	call GetJoypad
+
+; input override
+	ld a, [wDisableTextAcceleration]
+	and a
+	jr nz, .wait
+
+; Wait one frame if holding A or B.
+	ldh a, [hJoyDown]
+	bit A_BUTTON_F, a
+	jr z, .checkb
+	jr .delay
+.checkb
+	bit B_BUTTON_F, a
+	jr z, .wait
+
+.delay
+	call DelayFrame
+	jr .end
+
+.wait
+	ld a, [wTextDelayFrames]
+	and a
+	jr nz, .checkjoypad
+
+.end
+	pop bc
+	pop de
+	pop hl
+	ret
+
+CopyDataUntil::
+; Copy [hl .. bc) to de.
+
+; In other words, the source data is
+; from hl up to but not including bc,
+; and the destination is de.
+
+	ld a, [hli]
+	ld [de], a
+	inc de
+	ld a, h
+	cp b
+	jr nz, CopyDataUntil
+	ld a, l
+	cp c
+	jr nz, CopyDataUntil
+	ret
+
+PrintNum::
+	homecall _PrintNum
+	ret
+
+MobilePrintNum::
+	homecall _MobilePrintNum
+	ret
+
+FarPrintText::
+	ldh [hTempBank], a
+	ldh a, [hROMBank]
+	push af
+	ldh a, [hTempBank]
+	rst Bankswitch
+
+	call PrintText
+
+	pop af
+	rst Bankswitch
+	ret
+
+CallPointerAt::
+	ldh a, [hROMBank]
+	push af
+	ld a, [hli]
+	rst Bankswitch
+
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+	call _hl_
+
+	pop hl
+	ld a, h
+	rst Bankswitch
+	ret

home/printer.asm

@@ -0,0 +1,41 @@
+PrinterReceive::
+	homecall _PrinterReceive
+	ret
+
+AskSerial::
+; send out a handshake while serial int is off
+	ld a, [wPrinterConnectionOpen]
+	bit 0, a
+	ret z
+
+; if we're still interpreting data, don't try to receive
+	ld a, [wPrinterOpcode]
+	and a
+	ret nz
+
+; once every 6 frames
+	ld hl, wHandshakeFrameDelay
+	inc [hl]
+	ld a, [hl]
+	cp 6
+	ret c
+
+	xor a
+	ld [hl], a
+
+	ld a, $0c
+	ld [wPrinterOpcode], a
+
+; handshake
+	ld a, $88
+	ldh [rSB], a
+
+; switch to internal clock
+	ld a, (0 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+
+; start transfer
+	ld a, (1 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+
+	ret

home/queue_script.asm

@@ -0,0 +1,12 @@
+QueueScript::
+; Push pointer hl in the current bank to wQueuedScriptBank.
+	ldh a, [hROMBank]
+
+FarQueueScript::
+; Push pointer a:hl to wQueuedScriptBank.
+	ld [wQueuedScriptBank], a
+	ld a, l
+	ld [wQueuedScriptAddr], a
+	ld a, h
+	ld [wQueuedScriptAddr + 1], a
+	ret

home/random.asm

@@ -0,0 +1,80 @@
+Random::
+; A simple hardware-based random number generator (RNG).
+
+; Two random numbers are generated by adding and subtracting
+; the divider to the respective values every time it's called.
+
+; The divider is a register that increments at a rate of 16384Hz.
+; For comparison, the Game Boy operates at a clock speed of 4.2MHz.
+
+; Additionally, an equivalent function is executed in VBlank.
+
+; This leaves a with the value in hRandomSub.
+
+	push bc
+
+	ldh a, [rDIV]
+	ld b, a
+	ldh a, [hRandomAdd]
+	adc b
+	ldh [hRandomAdd], a
+
+	ldh a, [rDIV]
+	ld b, a
+	ldh a, [hRandomSub]
+	sbc b
+	ldh [hRandomSub], a
+
+	pop bc
+	ret
+
+BattleRandom::
+; _BattleRandom lives in another bank.
+
+; It handles all RNG calls in the battle engine, allowing
+; link battles to remain in sync using a shared PRNG.
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_BattleRandom)
+	rst Bankswitch
+
+	call _BattleRandom
+
+	ld [wPredefHL + 1], a
+	pop af
+	rst Bankswitch
+	ld a, [wPredefHL + 1]
+	ret
+
+RandomRange::
+; Return a random number between 0 and a (non-inclusive).
+
+	push bc
+	ld c, a
+
+	; b = $100 % c
+	xor a
+	sub c
+.mod
+	sub c
+	jr nc, .mod
+	add c
+	ld b, a
+
+	; Get a random number
+	; from 0 to $ff - b.
+	push bc
+.loop
+	call Random
+	ldh a, [hRandomAdd]
+	ld c, a
+	add b
+	jr c, .loop
+	ld a, c
+	pop bc
+
+	call SimpleDivide
+
+	pop bc
+	ret

home/region.asm

@@ -0,0 +1,32 @@
+IsInJohto::
+; Return 0 if the player is in Johto, and 1 in Kanto.
+
+	ld a, [wMapGroup]
+	ld b, a
+	ld a, [wMapNumber]
+	ld c, a
+	call GetWorldMapLocation
+
+	cp LANDMARK_FAST_SHIP
+	jr z, .Johto
+
+	cp LANDMARK_SPECIAL
+	jr nz, .CheckRegion
+
+	ld a, [wBackupMapGroup]
+	ld b, a
+	ld a, [wBackupMapNumber]
+	ld c, a
+	call GetWorldMapLocation
+
+.CheckRegion:
+	cp KANTO_LANDMARK
+	jr nc, .Kanto
+
+.Johto:
+	xor a ; JOHTO_REGION
+	ret
+
+.Kanto:
+	ld a, KANTO_REGION
+	ret

home/scrolling_menu.asm

@@ -0,0 +1,61 @@
+ScrollingMenu::
+	call CopyMenuData
+	ldh a, [hROMBank]
+	push af
+
+	ld a, BANK(_ScrollingMenu) ; aka BANK(_InitScrollingMenu)
+	rst Bankswitch
+
+	call _InitScrollingMenu
+	call .UpdatePalettes
+	call _ScrollingMenu
+
+	pop af
+	rst Bankswitch
+
+	ld a, [wMenuJoypad]
+	ret
+
+.UpdatePalettes:
+	ld hl, wVramState
+	bit 0, [hl]
+	jp nz, UpdateTimePals
+	jp SetPalettes
+
+InitScrollingMenu::
+	ld a, [wMenuBorderTopCoord]
+	dec a
+	ld b, a
+	ld a, [wMenuBorderBottomCoord]
+	sub b
+	ld d, a
+	ld a, [wMenuBorderLeftCoord]
+	dec a
+	ld c, a
+	ld a, [wMenuBorderRightCoord]
+	sub c
+	ld e, a
+	push de
+	call Coord2Tile
+	pop bc
+	jp Textbox
+
+JoyTextDelay_ForcehJoyDown::
+	call DelayFrame
+
+	ldh a, [hInMenu]
+	push af
+	ld a, $1
+	ldh [hInMenu], a
+	call JoyTextDelay
+	pop af
+	ldh [hInMenu], a
+
+	ldh a, [hJoyLast]
+	and D_RIGHT + D_LEFT + D_UP + D_DOWN
+	ld c, a
+	ldh a, [hJoyPressed]
+	and A_BUTTON + B_BUTTON + SELECT + START
+	or c
+	ld c, a
+	ret

home/serial.asm

@@ -0,0 +1,407 @@
+Serial::
+; The serial interrupt.
+
+	push af
+	push bc
+	push de
+	push hl
+
+	ldh a, [hMobileReceive]
+	and a
+	jr nz, .mobile
+
+	ld a, [wPrinterConnectionOpen]
+	bit 0, a
+	jr nz, .printer
+
+	ldh a, [hSerialConnectionStatus]
+	inc a ; is it equal to CONNECTION_NOT_ESTABLISHED?
+	jr z, .establish_connection
+
+	ldh a, [rSB]
+	ldh [hSerialReceive], a
+
+	ldh a, [hSerialSend]
+	ldh [rSB], a
+
+	ldh a, [hSerialConnectionStatus]
+	cp USING_INTERNAL_CLOCK
+	jr z, .player2
+
+	ld a, (0 << rSC_ON) | (0 << rSC_CLOCK)
+	ldh [rSC], a
+	ld a, (1 << rSC_ON) | (0 << rSC_CLOCK)
+	ldh [rSC], a
+	jr .player2
+
+.mobile
+	call MobileReceive
+	jr .end
+
+.printer
+	call PrinterReceive
+	jr .end
+
+.establish_connection
+	ldh a, [rSB]
+	cp USING_EXTERNAL_CLOCK
+	jr z, .player1
+	cp USING_INTERNAL_CLOCK
+	jr nz, .player2
+
+.player1
+	ldh [hSerialReceive], a
+	ldh [hSerialConnectionStatus], a
+	cp USING_INTERNAL_CLOCK
+	jr z, ._player2
+
+	xor a
+	ldh [rSB], a
+
+	ld a, 3
+	ldh [rDIV], a
+.delay_loop
+	ldh a, [rDIV]
+	bit 7, a
+	jr nz, .delay_loop
+
+	ld a, (0 << rSC_ON) | (0 << rSC_CLOCK)
+	ldh [rSC], a
+	ld a, (1 << rSC_ON) | (0 << rSC_CLOCK)
+	ldh [rSC], a
+	jr .player2
+
+._player2
+	xor a
+	ldh [rSB], a
+
+.player2
+	ld a, TRUE
+	ldh [hSerialReceivedNewData], a
+	ld a, SERIAL_NO_DATA_BYTE
+	ldh [hSerialSend], a
+
+.end
+	pop hl
+	pop de
+	pop bc
+	pop af
+	reti
+
+Serial_ExchangeBytes::
+; send bc bytes from hl, receive bc bytes to de
+	ld a, TRUE
+	ldh [hSerialIgnoringInitialData], a
+
+.loop
+	ld a, [hl]
+	ldh [hSerialSend], a
+	call Serial_ExchangeByte
+	push bc
+	ld b, a
+	inc hl
+
+	ld a, 48
+.wait
+	dec a
+	jr nz, .wait
+
+	ldh a, [hSerialIgnoringInitialData]
+	and a
+	ld a, b
+	pop bc
+	jr z, .load
+	dec hl
+	cp SERIAL_PREAMBLE_BYTE
+	jr nz, .loop
+	xor a ; FALSE
+	ldh [hSerialIgnoringInitialData], a
+	jr .loop
+
+.load
+	ld [de], a
+	inc de
+	dec bc
+	ld a, b
+	or c
+	jr nz, .loop
+	ret
+
+Serial_ExchangeByte::
+.timeout_loop
+	xor a
+	ldh [hSerialReceivedNewData], a
+	ldh a, [hSerialConnectionStatus]
+	cp USING_INTERNAL_CLOCK
+	jr nz, .not_player_2
+	ld a, (0 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+	ld a, (1 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+.not_player_2
+.loop
+	ldh a, [hSerialReceivedNewData]
+	and a
+	jr nz, .await_new_data
+	ldh a, [hSerialConnectionStatus]
+	cp USING_EXTERNAL_CLOCK
+	jr nz, .not_player_1_or_timed_out
+	call CheckLinkTimeoutFramesNonzero
+	jr z, .not_player_1_or_timed_out
+	call .ShortDelay
+	push hl
+	ld hl, wLinkTimeoutFrames + 1
+	inc [hl]
+	jr nz, .no_rollover_up
+	dec hl
+	inc [hl]
+
+.no_rollover_up
+	pop hl
+	call CheckLinkTimeoutFramesNonzero
+	jr nz, .loop
+	jp SerialDisconnected
+
+.not_player_1_or_timed_out
+	ldh a, [rIE]
+	and (1 << SERIAL) | (1 << TIMER) | (1 << LCD_STAT) | (1 << VBLANK)
+	cp 1 << SERIAL
+	jr nz, .loop
+	ld a, [wLinkByteTimeout]
+	dec a
+	ld [wLinkByteTimeout], a
+	jr nz, .loop
+	ld a, [wLinkByteTimeout + 1]
+	dec a
+	ld [wLinkByteTimeout + 1], a
+	jr nz, .loop
+	ldh a, [hSerialConnectionStatus]
+	cp USING_EXTERNAL_CLOCK
+	jr z, .await_new_data
+
+	ld a, 255
+.long_delay_loop
+	dec a
+	jr nz, .long_delay_loop
+
+.await_new_data
+	xor a
+	ldh [hSerialReceivedNewData], a
+	ldh a, [rIE]
+	and (1 << SERIAL) | (1 << TIMER) | (1 << LCD_STAT) | (1 << VBLANK)
+	sub 1 << SERIAL
+	jr nz, .non_serial_interrupts_enabled
+
+	; a == 0
+	assert LOW(SERIAL_LINK_BYTE_TIMEOUT) == 0
+	ld [wLinkByteTimeout], a
+	ld a, HIGH(SERIAL_LINK_BYTE_TIMEOUT)
+	ld [wLinkByteTimeout + 1], a
+
+.non_serial_interrupts_enabled
+	ldh a, [hSerialReceive]
+	cp SERIAL_NO_DATA_BYTE
+	ret nz
+	call CheckLinkTimeoutFramesNonzero
+	jr z, .timed_out
+	push hl
+	ld hl, wLinkTimeoutFrames + 1
+	ld a, [hl]
+	dec a
+	ld [hld], a
+	inc a
+	jr nz, .no_rollover
+	dec [hl]
+
+.no_rollover
+	pop hl
+	call CheckLinkTimeoutFramesNonzero
+	jr z, SerialDisconnected
+
+.timed_out
+	ldh a, [rIE]
+	and (1 << SERIAL) | (1 << TIMER) | (1 << LCD_STAT) | (1 << VBLANK)
+	cp 1 << SERIAL
+	ld a, SERIAL_NO_DATA_BYTE
+	ret z
+	ld a, [hl]
+	ldh [hSerialSend], a
+	call DelayFrame
+	jp .timeout_loop
+
+.ShortDelay:
+	ld a, 15
+.short_delay_loop
+	dec a
+	jr nz, .short_delay_loop
+	ret
+
+CheckLinkTimeoutFramesNonzero::
+	push hl
+	ld hl, wLinkTimeoutFrames
+	ld a, [hli]
+	or [hl]
+	pop hl
+	ret
+
+; This sets wLinkTimeoutFrames to $ffff, since
+; a is always 0 when it is called.
+SerialDisconnected::
+	dec a
+	ld [wLinkTimeoutFrames], a
+	ld [wLinkTimeoutFrames + 1], a
+	ret
+
+; This is used to check that both players entered the same Cable Club room.
+Serial_ExchangeSyncBytes::
+	ld hl, wLinkPlayerSyncBuffer
+	ld de, wLinkReceivedSyncBuffer
+	ld c, 2
+	ld a, TRUE
+	ldh [hSerialIgnoringInitialData], a
+.exchange
+	call DelayFrame
+	ld a, [hl]
+	ldh [hSerialSend], a
+	call Serial_ExchangeByte
+	ld b, a
+	inc hl
+	ldh a, [hSerialIgnoringInitialData]
+	and a
+	ld a, FALSE
+	ldh [hSerialIgnoringInitialData], a
+	jr nz, .exchange
+	ld a, b
+	ld [de], a
+	inc de
+	dec c
+	jr nz, .exchange
+	ret
+
+Serial_PrintWaitingTextAndSyncAndExchangeNybble::
+	call LoadTilemapToTempTilemap
+	callfar PlaceWaitingText
+	call WaitLinkTransfer
+	jp SafeLoadTempTilemapToTilemap
+
+Serial_SyncAndExchangeNybble:: ; unreferenced
+	call LoadTilemapToTempTilemap
+	callfar PlaceWaitingText
+	jp WaitLinkTransfer ; pointless
+
+WaitLinkTransfer::
+	vc_hook Wireless_WaitLinkTransfer
+	ld a, $ff
+	ld [wOtherPlayerLinkAction], a
+.loop
+	call LinkTransfer
+	call DelayFrame
+	call CheckLinkTimeoutFramesNonzero
+	jr z, .check
+	push hl
+	ld hl, wLinkTimeoutFrames + 1
+	dec [hl]
+	jr nz, .skip
+	dec hl
+	dec [hl]
+	jr nz, .skip
+	; We might be disconnected
+	pop hl
+	xor a
+	jp SerialDisconnected
+
+.skip
+	pop hl
+
+.check
+	ld a, [wOtherPlayerLinkAction]
+	inc a
+	jr z, .loop
+
+	vc_patch Wireless_net_delay_1
+if DEF(_CRYSTAL_VC)
+	ld b, 26
+else
+	ld b, 10
+endc
+	vc_patch_end
+.receive
+	call DelayFrame
+	call LinkTransfer
+	dec b
+	jr nz, .receive
+
+	vc_patch Wireless_net_delay_2
+if DEF(_CRYSTAL_VC)
+	ld b, 26
+else
+	ld b, 10
+endc
+	vc_patch_end
+.acknowledge
+	call DelayFrame
+	call LinkDataReceived
+	dec b
+	jr nz, .acknowledge
+
+	ld a, [wOtherPlayerLinkAction]
+	ld [wOtherPlayerLinkMode], a
+	vc_hook Wireless_WaitLinkTransfer_ret
+	ret
+
+LinkTransfer::
+	push bc
+	ld b, SERIAL_TIMECAPSULE
+	ld a, [wLinkMode]
+	cp LINK_TIMECAPSULE
+	jr z, .got_high_nybble
+	ld b, SERIAL_TIMECAPSULE
+	jr c, .got_high_nybble
+	cp LINK_TRADECENTER
+	ld b, SERIAL_TRADECENTER
+	jr z, .got_high_nybble
+	ld b, SERIAL_BATTLE
+
+.got_high_nybble
+	call .Receive
+	ld a, [wPlayerLinkAction]
+	add b
+	ldh [hSerialSend], a
+	ldh a, [hSerialConnectionStatus]
+	cp USING_INTERNAL_CLOCK
+	jr nz, .player_1
+	ld a, (0 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+	ld a, (1 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+
+.player_1
+	call .Receive
+	pop bc
+	ret
+
+.Receive:
+	ldh a, [hSerialReceive]
+	ld [wOtherPlayerLinkMode], a
+	and $f0
+	cp b
+	ret nz
+	xor a
+	ldh [hSerialReceive], a
+	ld a, [wOtherPlayerLinkMode]
+	and $f
+	ld [wOtherPlayerLinkAction], a
+	ret
+
+LinkDataReceived::
+; Let the other system know that the data has been received.
+	xor a
+	ldh [hSerialSend], a
+	ldh a, [hSerialConnectionStatus]
+	cp USING_INTERNAL_CLOCK
+	ret nz
+	ld a, (0 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+	ld a, (1 << rSC_ON) | (1 << rSC_CLOCK)
+	ldh [rSC], a
+	ret

home/sine.asm

@@ -0,0 +1,9 @@
+Cosine:: ; unreferenced
+; a = d * cos(a * pi/32)
+	add %010000 ; cos(x) = sin(x + pi/2)
+	; fallthrough
+Sine::
+; a = d * sin(a * pi/32)
+	ld e, a
+	homecall _Sine
+	ret

home/sprite_anims.asm

@@ -0,0 +1,31 @@
+InitSpriteAnimStruct::
+	ld [wSpriteAnimID], a
+	ldh a, [hROMBank]
+	push af
+
+	ld a, BANK(_InitSpriteAnimStruct)
+	rst Bankswitch
+	ld a, [wSpriteAnimID]
+
+	call _InitSpriteAnimStruct
+
+	pop af
+	rst Bankswitch
+
+	ret
+
+ReinitSpriteAnimFrame::
+	ld [wSpriteAnimID], a
+	ldh a, [hROMBank]
+	push af
+
+	ld a, BANK(_ReinitSpriteAnimFrame)
+	rst Bankswitch
+	ld a, [wSpriteAnimID]
+
+	call _ReinitSpriteAnimFrame
+
+	pop af
+	rst Bankswitch
+
+	ret

home/sprite_updates.asm

@@ -0,0 +1,19 @@
+DisableSpriteUpdates::
+	xor a
+	ldh [hMapAnims], a
+	ld a, [wVramState]
+	res 0, a
+	ld [wVramState], a
+	xor a
+	ld [wSpriteUpdatesEnabled], a
+	ret
+
+EnableSpriteUpdates::
+	ld a, $1
+	ld [wSpriteUpdatesEnabled], a
+	ld a, [wVramState]
+	set 0, a
+	ld [wVramState], a
+	ld a, $1
+	ldh [hMapAnims], a
+	ret

home/sram.asm

@@ -0,0 +1,30 @@
+OpenSRAM::
+; if invalid bank, sram is disabled
+	cp NUM_SRAM_BANKS
+	jr nc, CloseSRAM
+
+; switch to sram bank a
+	push af
+; latch clock data
+	ld a, 1
+	ld [MBC3LatchClock], a
+; enable sram/clock write
+	ld a, SRAM_ENABLE
+	ld [MBC3SRamEnable], a
+; select sram bank
+	pop af
+	ldh [hSRAMBank], a
+	ld [MBC3SRamBank], a
+	ret
+
+CloseSRAM::
+	push af
+	ld a, -1
+	ldh [hSRAMBank], a
+	ld a, SRAM_DISABLE
+; reset clock latch for next time
+	ld [MBC3LatchClock], a
+; disable sram/clock write
+	ld [MBC3SRamEnable], a
+	pop af
+	ret

home/stone_queue.asm

@@ -0,0 +1,124 @@
+HandleStoneQueue::
+	ldh a, [hROMBank]
+	push af
+
+	call SwitchToMapScriptsBank
+	call .WarpAction
+
+	pop bc
+	ld a, b
+	rst Bankswitch
+	ret
+
+.WarpAction:
+	ld hl, OBJECT_MAP_OBJECT_INDEX
+	add hl, de
+	ld a, [hl]
+	cp $ff
+	ret nc
+
+	ld l, a
+	push hl
+	call .IsObjectOnWarp
+	pop hl
+	ret nc
+	ld d, a
+	ld e, l
+	call .IsObjectInStoneTable
+	ret nc
+	call CallMapScript
+	farcall EnableScriptMode
+	scf
+	ret
+
+.IsObjectOnWarp:
+	push de
+
+	ld hl, OBJECT_MAP_X
+	add hl, de
+	ld a, [hl]
+	ld hl, OBJECT_MAP_Y
+	add hl, de
+	ld e, [hl]
+
+	sub 4
+	ld d, a
+	ld a, e
+	sub 4
+	ld e, a
+	call .check_on_warp
+
+	pop de
+	ret
+
+.check_on_warp
+	ld hl, wCurMapWarpsPointer
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld a, [wCurMapWarpCount]
+	and a
+	ret z
+
+.loop
+	push af
+	ld a, [hl]
+	cp e
+	jr nz, .not_on_warp
+	inc hl
+	ld a, [hld]
+	cp d
+	jr z, .found_warp
+
+.not_on_warp
+	ld a, WARP_EVENT_SIZE
+	add l
+	ld l, a
+	jr nc, .no_carry
+	inc h
+.no_carry
+
+	pop af
+	dec a
+	jr nz, .loop
+	and a
+	ret
+
+.found_warp
+	pop af
+	ld d, a
+	ld a, [wCurMapWarpCount]
+	sub d
+	inc a
+	scf
+	ret
+
+.IsObjectInStoneTable:
+	inc e
+	ld hl, CMDQUEUE_ADDR
+	add hl, bc
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+.loop2
+	ld a, [hli]
+	cp $ff
+	ret z
+	cp d
+	jr nz, .next_inc3
+	ld a, [hli]
+	cp e
+	jr nz, .next_inc2
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	scf
+	ret
+
+.next_inc3
+	inc hl
+
+.next_inc2
+	inc hl
+	inc hl
+	jr .loop2

home/string.asm

@@ -0,0 +1,35 @@
+InitString::
+; Init a string of length c.
+	push hl
+	jr _InitString
+
+InitName::
+; Intended for names, so this function is limited to ten characters.
+	push hl
+	ld c, NAME_LENGTH - 1
+_InitString::
+; if the string pointed to by hl is empty (defined as "zero or more spaces
+; followed by a null"), then initialize it to the string pointed to by de.
+	push bc
+.loop
+	ld a, [hli]
+	cp "@"
+	jr z, .blank
+	cp " "
+	jr nz, .notblank
+	dec c
+	jr nz, .loop
+.blank
+	pop bc
+	ld l, e
+	ld h, d
+	pop de
+	ld b, 0
+	inc c
+	call CopyBytes
+	ret
+
+.notblank
+	pop bc
+	pop hl
+	ret

home/tilemap.asm

@@ -0,0 +1,226 @@
+ClearBGPalettes::
+	call ClearPalettes
+WaitBGMap::
+; Tell VBlank to update BG Map
+	ld a, 1 ; BG Map 0 tiles
+	ldh [hBGMapMode], a
+; Wait for it to do its magic
+	ld c, 4
+	jp DelayFrames
+
+WaitBGMap2::
+	ldh a, [hCGB]
+	and a
+	jr z, .bg0
+
+	ld a, 2
+	ldh [hBGMapMode], a
+	ld c, 4
+	call DelayFrames
+
+.bg0
+	ld a, 1
+	ldh [hBGMapMode], a
+	ld c, 4
+	jp DelayFrames
+
+IsCGB::
+	ldh a, [hCGB]
+	and a
+	ret
+
+ApplyTilemap::
+	ldh a, [hCGB]
+	and a
+	jr z, .dmg
+
+	ld a, [wSpriteUpdatesEnabled]
+	and a
+	jr z, .dmg
+
+	ld a, 1
+	ldh [hBGMapMode], a
+	jr CopyTilemapAtOnce
+
+.dmg
+; WaitBGMap
+	ld a, 1
+	ldh [hBGMapMode], a
+	ld c, 4
+	jp DelayFrames
+
+CGBOnly_CopyTilemapAtOnce::
+	ldh a, [hCGB]
+	and a
+	jr z, WaitBGMap
+
+CopyTilemapAtOnce::
+	ldh a, [hBGMapMode]
+	push af
+	xor a
+	ldh [hBGMapMode], a
+
+	ldh a, [hMapAnims]
+	push af
+	xor a
+	ldh [hMapAnims], a
+
+.wait
+	ldh a, [rLY]
+	cp $80 - 1
+	jr c, .wait
+
+	di
+	ld a, BANK(vBGMap2)
+	ldh [rVBK], a
+	hlcoord 0, 0, wAttrmap
+	call .CopyBGMapViaStack
+	ld a, BANK(vBGMap0)
+	ldh [rVBK], a
+	hlcoord 0, 0
+	call .CopyBGMapViaStack
+
+.wait2
+	ldh a, [rLY]
+	cp $80 - 1
+	jr c, .wait2
+	ei
+
+	pop af
+	ldh [hMapAnims], a
+	pop af
+	ldh [hBGMapMode], a
+	ret
+
+.CopyBGMapViaStack:
+; Copy all tiles to vBGMap
+	ld [hSPBuffer], sp
+	ld sp, hl
+	ldh a, [hBGMapAddress + 1]
+	ld h, a
+	ld l, 0
+	ld a, SCREEN_HEIGHT
+	ldh [hTilesPerCycle], a
+	ld b, 1 << 1 ; not in v/hblank
+	ld c, LOW(rSTAT)
+
+.loop
+rept SCREEN_WIDTH / 2
+	pop de
+; if in v/hblank, wait until not in v/hblank
+.loop\@
+	ldh a, [c]
+	and b
+	jr nz, .loop\@
+; load vBGMap
+	ld [hl], e
+	inc l
+	ld [hl], d
+	inc l
+endr
+
+	ld de, BG_MAP_WIDTH - SCREEN_WIDTH
+	add hl, de
+	ldh a, [hTilesPerCycle]
+	dec a
+	ldh [hTilesPerCycle], a
+	jr nz, .loop
+
+	ldh a, [hSPBuffer]
+	ld l, a
+	ldh a, [hSPBuffer + 1]
+	ld h, a
+	ld sp, hl
+	ret
+
+SetPalettes::
+; Inits the Palettes
+; depending on the system the monochromes palettes or color palettes
+	ldh a, [hCGB]
+	and a
+	jr nz, .SetPalettesForGameBoyColor
+	ld a, %11100100
+	ldh [rBGP], a
+	ld a, %11010000
+	ldh [rOBP0], a
+	ldh [rOBP1], a
+	ret
+
+.SetPalettesForGameBoyColor:
+	push de
+	ld a, %11100100
+	call DmgToCgbBGPals
+	lb de, %11100100, %11100100
+	call DmgToCgbObjPals
+	pop de
+	ret
+
+ClearPalettes::
+; Make all palettes white
+
+; CGB: make all the palette colors white
+	ldh a, [hCGB]
+	and a
+	jr nz, .cgb
+
+; DMG: just change palettes to 0 (white)
+	xor a
+	ldh [rBGP], a
+	ldh [rOBP0], a
+	ldh [rOBP1], a
+	ret
+
+.cgb
+	ldh a, [rSVBK]
+	push af
+
+	ld a, BANK(wBGPals2)
+	ldh [rSVBK], a
+
+; Fill wBGPals2 and wOBPals2 with $ffff (white)
+	ld hl, wBGPals2
+	ld bc, 16 palettes
+	ld a, $ff
+	call ByteFill
+
+	pop af
+	ldh [rSVBK], a
+
+; Request palette update
+	ld a, TRUE
+	ldh [hCGBPalUpdate], a
+	ret
+
+GetMemSGBLayout::
+	ld b, SCGB_DEFAULT
+GetSGBLayout::
+; load sgb packets unless dmg
+
+	ldh a, [hCGB]
+	and a
+	jr nz, .sgb
+
+	ldh a, [hSGB]
+	and a
+	ret z
+
+.sgb
+	predef_jump LoadSGBLayout
+
+SetHPPal::
+; Set palette for hp bar pixel length e at hl.
+	call GetHPPal
+	ld [hl], d
+	ret
+
+GetHPPal::
+; Get palette for hp bar pixel length e in d.
+	ld d, HP_GREEN
+	ld a, e
+	cp (HP_BAR_LENGTH_PX * 50 / 100) ; 24
+	ret nc
+	inc d ; HP_YELLOW
+	cp (HP_BAR_LENGTH_PX * 21 / 100) ; 10
+	ret nc
+	inc d ; HP_RED
+	ret

home/time.asm

@@ -0,0 +1,271 @@
+; Functions relating to the timer interrupt and the real-time-clock.
+
+Timer:: ; unreferenced
+	push af
+	ldh a, [hMobile]
+	and a
+	jr z, .not_mobile
+	call MobileTimer
+
+.not_mobile
+	pop af
+	reti
+
+LatchClock::
+; latch clock counter data
+	ld a, 0
+	ld [MBC3LatchClock], a
+	ld a, 1
+	ld [MBC3LatchClock], a
+	ret
+
+UpdateTime::
+	call GetClock
+	call FixDays
+	call FixTime
+	farcall GetTimeOfDay
+	ret
+
+GetClock::
+; store clock data in hRTCDayHi-hRTCSeconds
+
+; enable clock r/w
+	ld a, SRAM_ENABLE
+	ld [MBC3SRamEnable], a
+
+; clock data is 'backwards' in hram
+
+	call LatchClock
+	ld hl, MBC3SRamBank
+	ld de, MBC3RTC
+
+	ld [hl], RTC_S
+	ld a, [de]
+	maskbits 60
+	ldh [hRTCSeconds], a
+
+	ld [hl], RTC_M
+	ld a, [de]
+	maskbits 60
+	ldh [hRTCMinutes], a
+
+	ld [hl], RTC_H
+	ld a, [de]
+	maskbits 24
+	ldh [hRTCHours], a
+
+	ld [hl], RTC_DL
+	ld a, [de]
+	ldh [hRTCDayLo], a
+
+	ld [hl], RTC_DH
+	ld a, [de]
+	ldh [hRTCDayHi], a
+
+; unlatch clock / disable clock r/w
+	jp CloseSRAM
+
+FixDays::
+; fix day count
+; mod by 140
+
+; check if day count > 255 (bit 8 set)
+	ldh a, [hRTCDayHi] ; DH
+	bit 0, a
+	jr z, .daylo
+; reset dh (bit 8)
+	res 0, a
+	ldh [hRTCDayHi], a
+
+; mod 140
+; mod twice since bit 8 (DH) was set
+	ldh a, [hRTCDayLo]
+.modh
+	sub 140
+	jr nc, .modh
+.modl
+	sub 140
+	jr nc, .modl
+	add 140
+
+; update dl
+	ldh [hRTCDayLo], a
+
+; flag for sRTCStatusFlags
+	ld a, %01000000
+	jr .set
+
+.daylo
+; quit if fewer than 140 days have passed
+	ldh a, [hRTCDayLo]
+	cp 140
+	jr c, .quit
+
+; mod 140
+.mod
+	sub 140
+	jr nc, .mod
+	add 140
+
+; update dl
+	ldh [hRTCDayLo], a
+
+; flag for sRTCStatusFlags
+	ld a, %00100000
+
+.set
+; update clock with modded day value
+	push af
+	call SetClock
+	pop af
+	scf
+	ret
+
+.quit
+	xor a
+	ret
+
+FixTime::
+; add ingame time (set at newgame) to current time
+; store time in wCurDay, hHours, hMinutes, hSeconds
+
+; second
+	ldh a, [hRTCSeconds]
+	ld c, a
+	ld a, [wStartSecond]
+	add c
+	sub 60
+	jr nc, .updatesec
+	add 60
+.updatesec
+	ldh [hSeconds], a
+
+; minute
+	ccf ; carry is set, so turn it off
+	ldh a, [hRTCMinutes]
+	ld c, a
+	ld a, [wStartMinute]
+	adc c
+	sub 60
+	jr nc, .updatemin
+	add 60
+.updatemin
+	ldh [hMinutes], a
+
+; hour
+	ccf ; carry is set, so turn it off
+	ldh a, [hRTCHours]
+	ld c, a
+	ld a, [wStartHour]
+	adc c
+	sub 24
+	jr nc, .updatehr
+	add 24
+.updatehr
+	ldh [hHours], a
+
+; day
+	ccf ; carry is set, so turn it off
+	ldh a, [hRTCDayLo]
+	ld c, a
+	ld a, [wStartDay]
+	adc c
+	ld [wCurDay], a
+	ret
+
+InitTimeOfDay::
+	xor a
+	ld [wStringBuffer2], a
+	ld a, 0 ; useless
+	ld [wStringBuffer2 + 3], a
+	jr InitTime
+
+InitDayOfWeek::
+	call UpdateTime
+	ldh a, [hHours]
+	ld [wStringBuffer2 + 1], a
+	ldh a, [hMinutes]
+	ld [wStringBuffer2 + 2], a
+	ldh a, [hSeconds]
+	ld [wStringBuffer2 + 3], a
+	jr InitTime ; useless
+
+InitTime::
+	farcall _InitTime
+	ret
+
+ClearClock::
+	xor a
+	ldh [hRTCSeconds], a
+	ldh [hRTCMinutes], a
+	ldh [hRTCHours], a
+	ldh [hRTCDayLo], a
+	ldh [hRTCDayHi], a
+; fallthrough
+
+SetClock::
+; set clock data from hram
+
+; enable clock r/w
+	ld a, SRAM_ENABLE
+	ld [MBC3SRamEnable], a
+
+; set clock data
+; stored 'backwards' in hram
+
+	call LatchClock
+	ld hl, MBC3SRamBank
+	ld de, MBC3RTC
+
+; seconds
+	ld [hl], RTC_S
+	ldh a, [hRTCSeconds]
+	ld [de], a
+; minutes
+	ld [hl], RTC_M
+	ldh a, [hRTCMinutes]
+	ld [de], a
+; hours
+	ld [hl], RTC_H
+	ldh a, [hRTCHours]
+	ld [de], a
+; day lo
+	ld [hl], RTC_DL
+	ldh a, [hRTCDayLo]
+	ld [de], a
+; day hi
+	ld [hl], RTC_DH
+	ldh a, [hRTCDayHi]
+	res 6, a ; make sure timer is active
+	ld [de], a
+
+; cleanup
+	jp CloseSRAM ; unlatch clock, disable clock r/w
+
+ClearRTCStatus:: ; unreferenced
+; clear sRTCStatusFlags
+	xor a
+	push af
+	ld a, BANK(sRTCStatusFlags)
+	call OpenSRAM
+	pop af
+	ld [sRTCStatusFlags], a
+	jp CloseSRAM
+
+RecordRTCStatus::
+; append flags to sRTCStatusFlags
+	ld hl, sRTCStatusFlags
+	push af
+	ld a, BANK(sRTCStatusFlags)
+	call OpenSRAM
+	pop af
+	or [hl]
+	ld [hl], a
+	jp CloseSRAM
+
+CheckRTCStatus::
+; check sRTCStatusFlags
+	ld a, BANK(sRTCStatusFlags)
+	call OpenSRAM
+	ld a, [sRTCStatusFlags]
+	jp CloseSRAM

home/time_palettes.asm

@@ -0,0 +1,22 @@
+UpdateTimeAndPals::
+; update time and time-sensitive palettes
+
+; rtc enabled?
+	ld a, [wSpriteUpdatesEnabled]
+	cp 0
+	ret z
+
+	call UpdateTime
+
+; obj update on?
+	ld a, [wVramState]
+	bit 0, a ; obj update
+	ret z
+
+TimeOfDayPals::
+	callfar _TimeOfDayPals
+	ret
+
+UpdateTimePals::
+	callfar _UpdateTimePals
+	ret

home/trainers.asm

@@ -0,0 +1,244 @@
+CheckTrainerBattle::
+	ldh a, [hROMBank]
+	push af
+
+	call SwitchToMapScriptsBank
+	call _CheckTrainerBattle
+
+	pop bc
+	ld a, b
+	rst Bankswitch
+	ret
+
+_CheckTrainerBattle::
+; Check if any trainer on the map sees the player and wants to battle.
+
+; Skip the player object.
+	ld a, 1
+	ld de, wMap1Object
+
+.loop
+
+; Start a battle if the object:
+	push af
+	push de
+
+; Has a sprite
+	ld hl, MAPOBJECT_SPRITE
+	add hl, de
+	ld a, [hl]
+	and a
+	jr z, .next
+
+; Is a trainer
+	ld hl, MAPOBJECT_TYPE
+	add hl, de
+	ld a, [hl]
+	and MAPOBJECT_TYPE_MASK
+	cp OBJECTTYPE_TRAINER
+	jr nz, .next
+
+; Is visible on the map
+	ld hl, MAPOBJECT_OBJECT_STRUCT_ID
+	add hl, de
+	ld a, [hl]
+	cp -1
+	jr z, .next
+
+; Is facing the player...
+	call GetObjectStruct
+	call FacingPlayerDistance_bc
+	jr nc, .next
+
+; ...within their sight range
+	ld hl, MAPOBJECT_SIGHT_RANGE
+	add hl, de
+	ld a, [hl]
+	cp b
+	jr c, .next
+
+; And hasn't already been beaten
+	push bc
+	push de
+	ld hl, MAPOBJECT_SCRIPT_POINTER
+	add hl, de
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+	ld b, CHECK_FLAG
+	call EventFlagAction
+	ld a, c
+	pop de
+	pop bc
+	and a
+	jr z, .startbattle
+
+.next
+	pop de
+	ld hl, MAPOBJECT_LENGTH
+	add hl, de
+	ld d, h
+	ld e, l
+
+	pop af
+	inc a
+	cp NUM_OBJECTS
+	jr nz, .loop
+	xor a
+	ret
+
+.startbattle
+	pop de
+	pop af
+	ldh [hLastTalked], a
+	ld a, b
+	ld [wSeenTrainerDistance], a
+	ld a, c
+	ld [wSeenTrainerDirection], a
+	jr LoadTrainer_continue
+
+TalkToTrainer::
+	ld a, 1
+	ld [wSeenTrainerDistance], a
+	ld a, -1
+	ld [wSeenTrainerDirection], a
+
+LoadTrainer_continue::
+	call GetMapScriptsBank
+	ld [wSeenTrainerBank], a
+
+	ldh a, [hLastTalked]
+	call GetMapObject
+
+	ld hl, MAPOBJECT_SCRIPT_POINTER
+	add hl, bc
+	ld a, [wSeenTrainerBank]
+	call GetFarWord
+	ld de, wTempTrainer
+	ld bc, wTempTrainerEnd - wTempTrainer
+	ld a, [wSeenTrainerBank]
+	call FarCopyBytes
+	xor a
+	ld [wRunningTrainerBattleScript], a
+	scf
+	ret
+
+FacingPlayerDistance_bc::
+	push de
+	call FacingPlayerDistance
+	ld b, d
+	ld c, e
+	pop de
+	ret
+
+FacingPlayerDistance::
+; Return carry if the sprite at bc is facing the player,
+; its distance in d, and its direction in e.
+
+	ld hl, OBJECT_MAP_X ; x
+	add hl, bc
+	ld d, [hl]
+
+	ld hl, OBJECT_MAP_Y ; y
+	add hl, bc
+	ld e, [hl]
+
+	ld a, [wPlayerMapX]
+	cp d
+	jr z, .CheckY
+
+	ld a, [wPlayerMapY]
+	cp e
+	jr z, .CheckX
+
+	and a
+	ret
+
+.CheckY:
+	ld a, [wPlayerMapY]
+	sub e
+	jr z, .NotFacing
+	jr nc, .Above
+
+; Below
+	cpl
+	inc a
+	ld d, a
+	ld e, OW_UP
+	jr .CheckFacing
+
+.Above:
+	ld d, a
+	ld e, OW_DOWN
+	jr .CheckFacing
+
+.CheckX:
+	ld a, [wPlayerMapX]
+	sub d
+	jr z, .NotFacing
+	jr nc, .Left
+
+; Right
+	cpl
+	inc a
+	ld d, a
+	ld e, OW_LEFT
+	jr .CheckFacing
+
+.Left:
+	ld d, a
+	ld e, OW_RIGHT
+
+.CheckFacing:
+	call GetSpriteDirection
+	cp e
+	jr nz, .NotFacing
+	scf
+	ret
+
+.NotFacing:
+	and a
+	ret
+
+CheckTrainerFlag:: ; unreferenced
+	push bc
+	ld hl, OBJECT_MAP_OBJECT_INDEX
+	add hl, bc
+	ld a, [hl]
+	call GetMapObject
+	ld hl, MAPOBJECT_SCRIPT_POINTER
+	add hl, bc
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	call GetMapScriptsBank
+	call GetFarWord
+	ld d, h
+	ld e, l
+	push de
+	ld b, CHECK_FLAG
+	call EventFlagAction
+	pop de
+	ld a, c
+	and a
+	pop bc
+	ret
+
+PrintWinLossText::
+	ld a, [wBattleResult]
+	ld hl, wWinTextPointer
+	and $f ; WIN?
+	jr z, .ok
+	ld hl, wLossTextPointer
+
+.ok
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	call GetMapScriptsBank
+	call FarPrintText
+	call WaitBGMap
+	jp WaitPressAorB_BlinkCursor

home/vblank.asm

@@ -0,0 +1,421 @@
+; VBlank is the interrupt responsible for updating VRAM.
+
+; In Pokemon Crystal, VBlank has been hijacked to act as the
+; main loop. After time-sensitive graphics operations have been
+; performed, joypad input and sound functions are executed.
+
+; This prevents the display and audio output from lagging.
+
+VBlank::
+	push af
+	push bc
+	push de
+	push hl
+
+	ldh a, [hVBlank]
+	and 7
+
+	ld e, a
+	ld d, 0
+	ld hl, .VBlanks
+	add hl, de
+	add hl, de
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+	call _hl_
+
+	call GameTimer
+
+	pop hl
+	pop de
+	pop bc
+	pop af
+	reti
+
+.VBlanks:
+	dw VBlank0
+	dw VBlank1
+	dw VBlank2
+	dw VBlank3
+	dw VBlank4
+	dw VBlank5
+	dw VBlank6
+	dw VBlank0 ; just in case
+
+VBlank0::
+; normal operation
+
+; rng
+; scx, scy, wy, wx
+; bg map buffer
+; palettes
+; dma transfer
+; bg map
+; tiles
+; oam
+; joypad
+; sound
+
+	; inc frame counter
+	ld hl, hVBlankCounter
+	inc [hl]
+
+	; advance random variables
+	ldh a, [rDIV]
+	ld b, a
+	ldh a, [hRandomAdd]
+	adc b
+	ldh [hRandomAdd], a
+
+	ldh a, [rDIV]
+	ld b, a
+	ldh a, [hRandomSub]
+	sbc b
+	ldh [hRandomSub], a
+
+	ldh a, [hROMBank]
+	ldh [hROMBankBackup], a
+
+	ldh a, [hSCX]
+	ldh [rSCX], a
+	ldh a, [hSCY]
+	ldh [rSCY], a
+	ldh a, [hWY]
+	ldh [rWY], a
+	ldh a, [hWX]
+	ldh [rWX], a
+
+	; There's only time to call one of these in one vblank.
+	; Calls are in order of priority.
+
+	call UpdateBGMapBuffer
+	jr c, .done
+	call UpdatePalsIfCGB
+	jr c, .done
+	call DMATransfer
+	jr c, .done
+	call UpdateBGMap
+
+	; These have their own timing checks.
+
+	call Serve2bppRequest
+	call Serve1bppRequest
+	call AnimateTileset
+
+.done
+
+	ldh a, [hOAMUpdate]
+	and a
+	jr nz, .done_oam
+	call hTransferShadowOAM
+.done_oam
+
+	; vblank-sensitive operations are done
+
+	xor a
+	ld [wVBlankOccurred], a
+
+	ld a, [wOverworldDelay]
+	and a
+	jr z, .ok
+	dec a
+	ld [wOverworldDelay], a
+.ok
+
+	ld a, [wTextDelayFrames]
+	and a
+	jr z, .ok2
+	dec a
+	ld [wTextDelayFrames], a
+.ok2
+
+	call UpdateJoypad
+
+	ld a, BANK(_UpdateSound)
+	rst Bankswitch
+	call _UpdateSound
+	ldh a, [hROMBankBackup]
+	rst Bankswitch
+
+	ldh a, [hSeconds]
+	ldh [hUnusedBackup], a
+
+	ret
+
+VBlank2::
+; sound only
+
+	ldh a, [hROMBank]
+	ldh [hROMBankBackup], a
+
+	ld a, BANK(_UpdateSound)
+	rst Bankswitch
+	call _UpdateSound
+
+	ldh a, [hROMBankBackup]
+	rst Bankswitch
+
+	xor a
+	ld [wVBlankOccurred], a
+	ret
+
+VBlank1::
+; scx, scy
+; palettes
+; bg map
+; tiles
+; oam
+; sound / lcd stat
+
+	ldh a, [hROMBank]
+	ldh [hROMBankBackup], a
+
+	ldh a, [hSCX]
+	ldh [rSCX], a
+	ldh a, [hSCY]
+	ldh [rSCY], a
+
+	call UpdatePals
+	jr c, .done
+
+	call UpdateBGMap
+	call Serve2bppRequest_VBlank
+
+	call hTransferShadowOAM
+
+.done
+	xor a
+	ld [wVBlankOccurred], a
+
+	; get requested ints
+	ldh a, [rIF]
+	ld b, a
+	; discard requested ints
+	xor a
+	ldh [rIF], a
+	; enable lcd stat
+	ld a, 1 << LCD_STAT
+	ldh [rIE], a
+	; rerequest serial int if applicable (still disabled)
+	; request lcd stat
+	ld a, b
+	and 1 << SERIAL
+	or 1 << LCD_STAT
+	ldh [rIF], a
+
+	ei
+	ld a, BANK(_UpdateSound)
+	rst Bankswitch
+	call _UpdateSound
+	ldh a, [hROMBankBackup]
+	rst Bankswitch
+	di
+
+	; get requested ints
+	ldh a, [rIF]
+	ld b, a
+	; discard requested ints
+	xor a
+	ldh [rIF], a
+	; enable ints besides joypad
+	ld a, IE_DEFAULT
+	ldh [rIE], a
+	; rerequest ints
+	ld a, b
+	ldh [rIF], a
+	ret
+
+UpdatePals::
+; update pals for either dmg or cgb
+
+	ldh a, [hCGB]
+	and a
+	jp nz, UpdateCGBPals
+
+	; update gb pals
+	ld a, [wBGP]
+	ldh [rBGP], a
+	ld a, [wOBP0]
+	ldh [rOBP0], a
+	ld a, [wOBP1]
+	ldh [rOBP1], a
+
+	and a
+	ret
+
+VBlank3::
+; scx, scy
+; palettes
+; bg map
+; tiles
+; oam
+; sound / lcd stat
+
+	ldh a, [hROMBank]
+	ldh [hROMBankBackup], a
+
+	ldh a, [hSCX]
+	ldh [rSCX], a
+	ldh a, [hSCY]
+	ldh [rSCY], a
+
+	ldh a, [hCGBPalUpdate]
+	and a
+	call nz, ForceUpdateCGBPals
+	jr c, .done
+
+	call UpdateBGMap
+	call Serve2bppRequest_VBlank
+
+	call hTransferShadowOAM
+.done
+
+	xor a
+	ld [wVBlankOccurred], a
+
+	ldh a, [rIF]
+	push af
+	xor a
+	ldh [rIF], a
+	ld a, 1 << LCD_STAT
+	ldh [rIE], a
+	ldh [rIF], a
+
+	ei
+	ld a, BANK(_UpdateSound)
+	rst Bankswitch
+	call _UpdateSound
+	ldh a, [hROMBankBackup]
+	rst Bankswitch
+	di
+
+	; request lcdstat
+	ldh a, [rIF]
+	ld b, a
+	; and any other ints
+	pop af
+	or b
+	ld b, a
+	; reset ints
+	xor a
+	ldh [rIF], a
+	; enable ints besides joypad
+	ld a, IE_DEFAULT
+	ldh [rIE], a
+	; request ints
+	ld a, b
+	ldh [rIF], a
+	ret
+
+VBlank4::
+; bg map
+; tiles
+; oam
+; joypad
+; serial
+; sound
+
+	ldh a, [hROMBank]
+	ldh [hROMBankBackup], a
+
+	call UpdateBGMap
+	call Serve2bppRequest
+
+	call hTransferShadowOAM
+
+	call UpdateJoypad
+
+	xor a
+	ld [wVBlankOccurred], a
+
+	call AskSerial
+
+	ld a, BANK(_UpdateSound)
+	rst Bankswitch
+	call _UpdateSound
+
+	ldh a, [hROMBankBackup]
+	rst Bankswitch
+	ret
+
+VBlank5::
+; scx
+; palettes
+; bg map
+; tiles
+; joypad
+;
+
+	ldh a, [hROMBank]
+	ldh [hROMBankBackup], a
+
+	ldh a, [hSCX]
+	ldh [rSCX], a
+
+	call UpdatePalsIfCGB
+	jr c, .done
+
+	call UpdateBGMap
+	call Serve2bppRequest
+.done
+
+	xor a
+	ld [wVBlankOccurred], a
+
+	call UpdateJoypad
+
+	xor a
+	ldh [rIF], a
+	ld a, 1 << LCD_STAT
+	ldh [rIE], a
+	; request lcd stat
+	ldh [rIF], a
+
+	ei
+	ld a, BANK(_UpdateSound)
+	rst Bankswitch
+	call _UpdateSound
+	ldh a, [hROMBankBackup]
+	rst Bankswitch
+	di
+
+	xor a
+	ldh [rIF], a
+	; enable ints besides joypad
+	ld a, IE_DEFAULT
+	ldh [rIE], a
+	ret
+
+VBlank6::
+; palettes
+; tiles
+; dma transfer
+; sound
+
+	ldh a, [hROMBank]
+	ldh [hROMBankBackup], a
+
+	; inc frame counter
+	ld hl, hVBlankCounter
+	inc [hl]
+
+	call UpdateCGBPals
+	jr c, .done
+
+	call Serve2bppRequest
+	call Serve1bppRequest
+	call DMATransfer
+.done
+
+	xor a
+	ld [wVBlankOccurred], a
+
+	ld a, BANK(_UpdateSound)
+	rst Bankswitch
+	call _UpdateSound
+
+	ldh a, [hROMBankBackup]
+	rst Bankswitch
+	ret

home/video.asm

@@ -0,0 +1,459 @@
+; Functions dealing with VRAM.
+
+DMATransfer::
+; Return carry if the transfer is completed.
+
+	ldh a, [hDMATransfer]
+	and a
+	ret z
+
+; Start transfer
+	ldh [rHDMA5], a
+
+; Execution is halted until the transfer is complete.
+
+	xor a
+	ldh [hDMATransfer], a
+	scf
+	ret
+
+UpdateBGMapBuffer::
+; Copy [hBGMapTileCount] 16x8 tiles from wBGMapBuffer
+; to bg map addresses in wBGMapBufferPointers.
+
+; [hBGMapTileCount] must be even since this is done in pairs.
+
+; Return carry on success.
+
+	ldh a, [hBGMapUpdate]
+	and a
+	ret z
+
+	ldh a, [rVBK]
+	push af
+
+; Relocate the stack pointer to wBGMapBufferPointers
+	ld [hSPBuffer], sp
+	ld hl, wBGMapBufferPointers
+	ld sp, hl
+
+; We can now pop the addresses of affected spots on the BG Map
+
+	ld hl, wBGMapPalBuffer
+	ld de, wBGMapBuffer
+
+.next
+; Copy a pair of 16x8 blocks (one 16x16 block)
+
+rept 2
+; Get our BG Map address
+	pop bc
+
+; Palettes
+	ld a, 1
+	ldh [rVBK], a
+
+	ld a, [hli]
+	ld [bc], a
+	inc c
+	ld a, [hli]
+	ld [bc], a
+	dec c
+
+; Tiles
+	xor a
+	ldh [rVBK], a
+
+	ld a, [de]
+	inc de
+	ld [bc], a
+	inc c
+	ld a, [de]
+	inc de
+	ld [bc], a
+endr
+
+; We've done 2 16x8 blocks
+	ldh a, [hBGMapTileCount]
+	dec a
+	dec a
+	ldh [hBGMapTileCount], a
+
+	jr nz, .next
+
+; Restore the stack pointer
+	ldh a, [hSPBuffer]
+	ld l, a
+	ldh a, [hSPBuffer + 1]
+	ld h, a
+	ld sp, hl
+
+	pop af
+	ldh [rVBK], a
+
+	xor a
+	ldh [hBGMapUpdate], a
+	scf
+	ret
+
+WaitTop::
+; Wait until the top third of the BG Map is being updated.
+
+	ldh a, [hBGMapMode]
+	and a
+	ret z
+
+	ldh a, [hBGMapThird]
+	and a
+	jr z, .done
+
+	call DelayFrame
+	jr WaitTop
+
+.done
+	xor a
+	ldh [hBGMapMode], a
+	ret
+
+UpdateBGMap::
+; Update the BG Map, in thirds, from wTilemap and wAttrmap.
+
+	ldh a, [hBGMapMode]
+	and a ; 0
+	ret z
+
+; BG Map 0
+	dec a ; 1
+	jr z, .Tiles
+	dec a ; 2
+	jr z, .Attr
+
+; BG Map 1
+	dec a ; useless
+
+	ldh a, [hBGMapAddress]
+	ld l, a
+	ldh a, [hBGMapAddress + 1]
+	ld h, a
+	push hl
+
+	xor a ; LOW(vBGMap1)
+	ldh [hBGMapAddress], a
+	ld a, HIGH(vBGMap1)
+	ldh [hBGMapAddress + 1], a
+
+	ldh a, [hBGMapMode]
+	push af
+	cp 3
+	call z, .Tiles
+	pop af
+	cp 4
+	call z, .Attr
+
+	pop hl
+	ld a, l
+	ldh [hBGMapAddress], a
+	ld a, h
+	ldh [hBGMapAddress + 1], a
+	ret
+
+.Attr:
+	ld a, 1
+	ldh [rVBK], a
+
+	hlcoord 0, 0, wAttrmap
+	call .update
+
+	xor a
+	ldh [rVBK], a
+	ret
+
+.Tiles:
+	hlcoord 0, 0
+
+.update
+	ld [hSPBuffer], sp
+
+; Which third?
+	ldh a, [hBGMapThird]
+	and a ; 0
+	jr z, .top
+	dec a ; 1
+	jr z, .middle
+	; 2
+
+DEF THIRD_HEIGHT EQU SCREEN_HEIGHT / 3
+
+; bottom
+	ld de, 2 * THIRD_HEIGHT * SCREEN_WIDTH
+	add hl, de
+	ld sp, hl
+
+	ldh a, [hBGMapAddress + 1]
+	ld h, a
+	ldh a, [hBGMapAddress]
+	ld l, a
+
+	ld de, 2 * THIRD_HEIGHT * BG_MAP_WIDTH
+	add hl, de
+
+; Next time: top third
+	xor a
+	jr .start
+
+.middle
+	ld de, THIRD_HEIGHT * SCREEN_WIDTH
+	add hl, de
+	ld sp, hl
+
+	ldh a, [hBGMapAddress + 1]
+	ld h, a
+	ldh a, [hBGMapAddress]
+	ld l, a
+
+	ld de, THIRD_HEIGHT * BG_MAP_WIDTH
+	add hl, de
+
+; Next time: bottom third
+	ld a, 2
+	jr .start
+
+.top
+	ld sp, hl
+
+	ldh a, [hBGMapAddress + 1]
+	ld h, a
+	ldh a, [hBGMapAddress]
+	ld l, a
+
+; Next time: middle third
+	ld a, 1
+
+.start
+; Which third to update next time
+	ldh [hBGMapThird], a
+
+; Rows of tiles in a third
+	ld a, THIRD_HEIGHT
+
+; Discrepancy between wTilemap and BGMap
+	ld bc, BG_MAP_WIDTH - (SCREEN_WIDTH - 1)
+
+.row
+; Copy a row of 20 tiles
+rept SCREEN_WIDTH / 2 - 1
+	pop de
+	ld [hl], e
+	inc l
+	ld [hl], d
+	inc l
+endr
+	pop de
+	ld [hl], e
+	inc l
+	ld [hl], d
+
+	add hl, bc
+	dec a
+	jr nz, .row
+
+	ldh a, [hSPBuffer]
+	ld l, a
+	ldh a, [hSPBuffer + 1]
+	ld h, a
+	ld sp, hl
+	ret
+
+Serve1bppRequest::
+; Only call during the first fifth of VBlank
+
+	ld a, [wRequested1bppSize]
+	and a
+	ret z
+
+; Back out if we're too far into VBlank
+	ldh a, [rLY]
+	cp LY_VBLANK
+	ret c
+	cp LY_VBLANK + 2
+	ret nc
+
+; Copy [wRequested1bppSize] 1bpp tiles from [wRequested1bppSource] to [wRequested1bppDest]
+
+	ld [hSPBuffer], sp
+
+; Source
+	ld hl, wRequested1bppSource
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld sp, hl
+
+; Destination
+	ld hl, wRequested1bppDest
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+; # tiles to copy
+	ld a, [wRequested1bppSize]
+	ld b, a
+
+	xor a
+	ld [wRequested1bppSize], a
+
+.next
+
+rept 3
+	pop de
+	ld [hl], e
+	inc l
+	ld [hl], e
+	inc l
+	ld [hl], d
+	inc l
+	ld [hl], d
+	inc l
+endr
+	pop de
+	ld [hl], e
+	inc l
+	ld [hl], e
+	inc l
+	ld [hl], d
+	inc l
+	ld [hl], d
+
+	inc hl
+	dec b
+	jr nz, .next
+
+	ld a, l
+	ld [wRequested1bppDest], a
+	ld a, h
+	ld [wRequested1bppDest + 1], a
+
+	ld [wRequested1bppSource], sp
+
+	ldh a, [hSPBuffer]
+	ld l, a
+	ldh a, [hSPBuffer + 1]
+	ld h, a
+	ld sp, hl
+	ret
+
+Serve2bppRequest::
+; Only call during the first fifth of VBlank
+
+	ld a, [wRequested2bppSize]
+	and a
+	ret z
+
+; Back out if we're too far into VBlank
+	ldh a, [rLY]
+	cp LY_VBLANK
+	ret c
+	cp LY_VBLANK + 2
+	ret nc
+	jr _Serve2bppRequest
+
+Serve2bppRequest_VBlank::
+	ld a, [wRequested2bppSize]
+	and a
+	ret z
+
+_Serve2bppRequest::
+; Copy [wRequested2bppSize] 2bpp tiles from [wRequested2bppSource] to [wRequested2bppDest]
+
+	ld [hSPBuffer], sp
+
+; Source
+	ld hl, wRequested2bppSource
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	ld sp, hl
+
+; Destination
+	ld hl, wRequested2bppDest
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+
+; # tiles to copy
+	ld a, [wRequested2bppSize]
+	ld b, a
+
+	xor a
+	ld [wRequested2bppSize], a
+
+.next
+
+rept 7
+	pop de
+	ld [hl], e
+	inc l
+	ld [hl], d
+	inc l
+endr
+	pop de
+	ld [hl], e
+	inc l
+	ld [hl], d
+
+	inc hl
+	dec b
+	jr nz, .next
+
+	ld a, l
+	ld [wRequested2bppDest], a
+	ld a, h
+	ld [wRequested2bppDest + 1], a
+
+	ld [wRequested2bppSource], sp
+
+	ldh a, [hSPBuffer]
+	ld l, a
+	ldh a, [hSPBuffer + 1]
+	ld h, a
+	ld sp, hl
+	ret
+
+AnimateTileset::
+; Only call during the first fifth of VBlank
+
+	ldh a, [hMapAnims]
+	and a
+	ret z
+
+; Back out if we're too far into VBlank
+	ldh a, [rLY]
+	cp LY_VBLANK
+	ret c
+	cp LY_VBLANK + 7
+	ret nc
+
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(_AnimateTileset)
+	rst Bankswitch
+
+	ldh a, [rSVBK]
+	push af
+	ld a, BANK(wTilesetAnim)
+	ldh [rSVBK], a
+
+	ldh a, [rVBK]
+	push af
+	xor a
+	ldh [rVBK], a
+
+	call _AnimateTileset
+
+	pop af
+	ldh [rVBK], a
+	pop af
+	ldh [rSVBK], a
+	pop af
+	rst Bankswitch
+	ret

home/window.asm

@@ -0,0 +1,93 @@
+RefreshScreen::
+	call ClearWindowData
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(ReanchorBGMap_NoOAMUpdate) ; aka BANK(LoadFonts_NoOAMUpdate)
+	rst Bankswitch
+
+	call ReanchorBGMap_NoOAMUpdate
+	call _OpenAndCloseMenu_HDMATransferTilemapAndAttrmap
+	call LoadFonts_NoOAMUpdate
+
+	pop af
+	rst Bankswitch
+	ret
+
+CloseText::
+	ldh a, [hOAMUpdate]
+	push af
+	ld a, $1
+	ldh [hOAMUpdate], a
+
+	call .CloseText
+
+	pop af
+	ldh [hOAMUpdate], a
+	ld hl, wVramState
+	res 6, [hl]
+	ret
+
+.CloseText:
+	call ClearWindowData
+	xor a
+	ldh [hBGMapMode], a
+	call OverworldTextModeSwitch
+	call _OpenAndCloseMenu_HDMATransferTilemapAndAttrmap
+	xor a
+	ldh [hBGMapMode], a
+	call SafeUpdateSprites
+	ld a, $90
+	ldh [hWY], a
+	call UpdatePlayerSprite
+	farcall InitMapNameSign
+	farcall LoadOverworldFont
+	ret
+
+OpenText::
+	call ClearWindowData
+	ldh a, [hROMBank]
+	push af
+	ld a, BANK(ReanchorBGMap_NoOAMUpdate) ; aka BANK(LoadFonts_NoOAMUpdate)
+	rst Bankswitch
+
+	call ReanchorBGMap_NoOAMUpdate ; clear bgmap
+	call SpeechTextbox
+	call _OpenAndCloseMenu_HDMATransferTilemapAndAttrmap ; anchor bgmap
+	call LoadFonts_NoOAMUpdate ; load font
+	pop af
+	rst Bankswitch
+
+	ret
+
+_OpenAndCloseMenu_HDMATransferTilemapAndAttrmap::
+	ldh a, [hOAMUpdate]
+	push af
+	ld a, $1
+	ldh [hOAMUpdate], a
+
+	farcall OpenAndCloseMenu_HDMATransferTilemapAndAttrmap
+
+	pop af
+	ldh [hOAMUpdate], a
+	ret
+
+SafeUpdateSprites::
+	ldh a, [hOAMUpdate]
+	push af
+	ldh a, [hBGMapMode]
+	push af
+	xor a
+	ldh [hBGMapMode], a
+	ld a, $1
+	ldh [hOAMUpdate], a
+
+	call UpdateSprites
+
+	xor a
+	ldh [hOAMUpdate], a
+	call DelayFrame
+	pop af
+	ldh [hBGMapMode], a
+	pop af
+	ldh [hOAMUpdate], a
+	ret