1 files changed, 854 insertions, 0 deletions
diff --git a/de/engine/menu/start_sub_menus.asm b/de/engine/menu/start_sub_menus.asm
new file mode 100755
index 00000000..f31c5d65
--- /dev/null
+++ b/de/engine/menu/start_sub_menus.asm
@@ -0,0 +1,854 @@
+StartMenu_Pokedex:
+	predef ShowPokedexMenu
+	call LoadScreenTilesFromBuffer2 ; restore saved screen
+	call Delay3
+	call LoadGBPal
+	call UpdateSprites
+	jp RedisplayStartMenu
+
+StartMenu_Pokemon:
+	ld a,[wPartyCount]
+	and a
+	jp z,RedisplayStartMenu
+	xor a
+	ld [wMenuItemToSwap],a
+	ld [wPartyMenuTypeOrMessageID],a
+	ld [wUpdateSpritesEnabled],a
+	call DisplayPartyMenu
+	jr .checkIfPokemonChosen
+.loop
+	xor a
+	ld [wMenuItemToSwap],a
+	ld [wPartyMenuTypeOrMessageID],a
+	call GoBackToPartyMenu
+.checkIfPokemonChosen
+	jr nc,.chosePokemon
+.exitMenu
+	call GBPalWhiteOutWithDelay3
+	call RestoreScreenTilesAndReloadTilePatterns
+	call LoadGBPal
+	jp RedisplayStartMenu
+.chosePokemon
+	call SaveScreenTilesToBuffer1
+	ld a,FIELD_MOVE_MON_MENU
+	ld [wTextBoxID],a
+	call DisplayTextBoxID ; display pokemon menu options
+	ld hl,wFieldMoves
+	lb bc, 2, 12 ; max menu item ID, top menu item Y
+	ld e,5
+.adjustMenuVariablesLoop
+	dec e
+	jr z,.storeMenuVariables
+	ld a,[hli]
+	and a ; end of field moves?
+	jr z,.storeMenuVariables
+	inc b
+	dec c
+	dec c
+	jr .adjustMenuVariablesLoop
+.storeMenuVariables
+	ld hl,wTopMenuItemY
+	ld a,c
+	ld [hli],a ; top menu item Y
+	ld a,[hFieldMoveMonMenuTopMenuItemX]
+	ld [hli],a ; top menu item X
+	xor a
+	ld [hli],a ; current menu item ID
+	inc hl
+	ld a,b
+	ld [hli],a ; max menu item ID
+	ld a,A_BUTTON | B_BUTTON
+	ld [hli],a ; menu watched keys
+	xor a
+	ld [hl],a
+	call HandleMenuInput
+	push af
+	call LoadScreenTilesFromBuffer1 ; restore saved screen
+	pop af
+	bit 1,a ; was the B button pressed?
+	jp nz,.loop
+; if the B button wasn't pressed
+	ld a,[wMaxMenuItem]
+	ld b,a
+	ld a,[wCurrentMenuItem] ; menu selection
+	cp b
+	jp z,.exitMenu ; if the player chose Cancel
+	dec b
+	cp b
+	jr z,.choseSwitch
+	dec b
+	cp b
+	jp z,.choseStats
+	ld c,a
+	ld b,0
+	ld hl,wFieldMoves
+	add hl,bc
+	jp .choseOutOfBattleMove
+.choseSwitch
+	ld a,[wPartyCount]
+	cp a,2 ; is there more than one pokemon in the party?
+	jp c,StartMenu_Pokemon ; if not, no switching
+	call SwitchPartyMon_InitVarOrSwapData ; init [wMenuItemToSwap]
+	ld a,SWAP_MONS_PARTY_MENU
+	ld [wPartyMenuTypeOrMessageID],a
+	call GoBackToPartyMenu
+	jp .checkIfPokemonChosen
+.choseStats
+	call ClearSprites
+	xor a ; PLAYER_PARTY_DATA
+	ld [wMonDataLocation],a
+	predef StatusScreen
+	predef StatusScreen2
+	call ReloadMapData
+	jp StartMenu_Pokemon
+.choseOutOfBattleMove
+	push hl
+	ld a,[wWhichPokemon]
+	ld hl,wPartyMonNicks
+	call GetPartyMonName
+	pop hl
+	ld a,[hl]
+	dec a
+	add a
+	ld b,0
+	ld c,a
+	ld hl,.outOfBattleMovePointers
+	add hl,bc
+	ld a,[hli]
+	ld h,[hl]
+	ld l,a
+	ld a,[wObtainedBadges] ; badges obtained
+	jp hl
+.outOfBattleMovePointers
+	dw .cut
+	dw .fly
+	dw .surf
+	dw .surf
+	dw .strength
+	dw .flash
+	dw .dig
+	dw .teleport
+	dw .softboiled
+.fly
+	bit 2,a ; does the player have the Thunder Badge?
+	jp z,.newBadgeRequired
+	call CheckIfInOutsideMap
+	jr z,.canFly
+	ld a,[wWhichPokemon]
+	ld hl,wPartyMonNicks
+	call GetPartyMonName
+	ld hl,.cannotFlyHereText
+	call PrintText
+	jp .loop
+.canFly
+	call ChooseFlyDestination
+	ld a,[wd732]
+	bit 3,a ; did the player decide to fly?
+	jp nz,.goBackToMap
+	call LoadFontTilePatterns
+	ld hl,wd72e
+	set 1,[hl]
+	jp StartMenu_Pokemon
+.cut
+	bit 1,a ; does the player have the Cascade Badge?
+	jp z,.newBadgeRequired
+	predef UsedCut
+	ld a,[wActionResultOrTookBattleTurn]
+	and a
+	jp z,.loop
+	jp CloseTextDisplay
+.surf
+	bit 4,a ; does the player have the Soul Badge?
+	jp z,.newBadgeRequired
+	callba IsSurfingAllowed
+	ld hl,wd728
+	bit 1,[hl]
+	res 1,[hl]
+	jp z,.loop
+	ld a,SURFBOARD
+	ld [wcf91],a
+	ld [wPseudoItemID],a
+	call UseItem
+	ld a,[wActionResultOrTookBattleTurn]
+	and a
+	jp z,.loop
+	call GBPalWhiteOutWithDelay3
+	jp .goBackToMap
+.strength
+	bit 3,a ; does the player have the Rainbow Badge?
+	jp z,.newBadgeRequired
+	predef PrintStrengthTxt
+	call GBPalWhiteOutWithDelay3
+	jp .goBackToMap
+.flash
+	bit 0,a ; does the player have the Boulder Badge?
+	jp z,.newBadgeRequired
+	xor a
+	ld [wMapPalOffset],a
+	ld hl,.flashLightsAreaText
+	call PrintText
+	call GBPalWhiteOutWithDelay3
+	jp .goBackToMap
+.flashLightsAreaText
+	TX_FAR _FlashLightsAreaText
+	db "@"
+.dig
+	ld a,ESCAPE_ROPE
+	ld [wcf91],a
+	ld [wPseudoItemID],a
+	call UseItem
+	ld a,[wActionResultOrTookBattleTurn]
+	and a
+	jp z,.loop
+	call GBPalWhiteOutWithDelay3
+	jp .goBackToMap
+.teleport
+	call CheckIfInOutsideMap
+	jr z,.canTeleport
+	ld a,[wWhichPokemon]
+	ld hl,wPartyMonNicks
+	call GetPartyMonName
+	ld hl,.cannotUseTeleportNowText
+	call PrintText
+	jp .loop
+.canTeleport
+	ld hl,.warpToLastPokemonCenterText
+	call PrintText
+	ld hl,wd732
+	set 3,[hl]
+	set 6,[hl]
+	ld hl,wd72e
+	set 1,[hl]
+	res 4,[hl]
+	ld c,60
+	call DelayFrames
+	call GBPalWhiteOutWithDelay3
+	jp .goBackToMap
+.warpToLastPokemonCenterText
+	TX_FAR _WarpToLastPokemonCenterText
+	db "@"
+.cannotUseTeleportNowText
+	TX_FAR _CannotUseTeleportNowText
+	db "@"
+.cannotFlyHereText
+	TX_FAR _CannotFlyHereText
+	db "@"
+.softboiled
+	ld hl,wPartyMon1MaxHP
+	ld a,[wWhichPokemon]
+	ld bc,wPartyMon2 - wPartyMon1
+	call AddNTimes
+	ld a,[hli]
+	ld [H_DIVIDEND],a
+	ld a,[hl]
+	ld [H_DIVIDEND + 1],a
+	ld a,5
+	ld [H_DIVISOR],a
+	ld b,2 ; number of bytes
+	call Divide
+	ld bc,wPartyMon1HP - wPartyMon1MaxHP
+	add hl,bc
+	ld a,[hld]
+	ld b,a
+	ld a,[H_QUOTIENT + 3]
+	sub b
+	ld b,[hl]
+	ld a,[H_QUOTIENT + 2]
+	sbc b
+	jp nc,.notHealthyEnough
+	ld a,[wPartyAndBillsPCSavedMenuItem]
+	push af
+	ld a,POTION
+	ld [wcf91],a
+	ld [wPseudoItemID],a
+	call UseItem
+	pop af
+	ld [wPartyAndBillsPCSavedMenuItem],a
+	jp .loop
+.notHealthyEnough ; if current HP is less than 1/5 of max HP
+	ld hl,.notHealthyEnoughText
+	call PrintText
+	jp .loop
+.notHealthyEnoughText
+	TX_FAR _NotHealthyEnoughText
+	db "@"
+.goBackToMap
+	call RestoreScreenTilesAndReloadTilePatterns
+	jp CloseTextDisplay
+.newBadgeRequired
+	ld hl,.newBadgeRequiredText
+	call PrintText
+	jp .loop
+.newBadgeRequiredText
+	TX_FAR _NewBadgeRequiredText
+	db "@"
+
+; writes a blank tile to all possible menu cursor positions on the party menu
+ErasePartyMenuCursors:
+	coord hl, 0, 1
+	ld bc,2 * 20 ; menu cursor positions are 2 rows apart
+	ld a,6 ; 6 menu cursor positions
+.loop
+	ld [hl]," "
+	add hl,bc
+	dec a
+	jr nz,.loop
+	ret
+
+ItemMenuLoop:
+	call LoadScreenTilesFromBuffer2DisableBGTransfer ; restore saved screen
+	call RunDefaultPaletteCommand
+
+StartMenu_Item:
+	ld a,[wLinkState]
+	dec a ; is the player in the Colosseum or Trade Centre?
+	jr nz,.notInCableClubRoom
+	ld hl,CannotUseItemsHereText
+	call PrintText
+	jr .exitMenu
+.notInCableClubRoom
+	ld bc,wNumBagItems
+	ld hl,wListPointer
+	ld a,c
+	ld [hli],a
+	ld [hl],b ; store item bag pointer in wListPointer (for DisplayListMenuID)
+	xor a
+	ld [wPrintItemPrices],a
+	ld a,ITEMLISTMENU
+	ld [wListMenuID],a
+	ld a,[wBagSavedMenuItem]
+	ld [wCurrentMenuItem],a
+	call DisplayListMenuID
+	ld a,[wCurrentMenuItem]
+	ld [wBagSavedMenuItem],a
+	jr nc,.choseItem
+.exitMenu
+	call LoadScreenTilesFromBuffer2 ; restore saved screen
+	call LoadTextBoxTilePatterns
+	call UpdateSprites
+	jp RedisplayStartMenu
+.choseItem
+; erase menu cursor (blank each tile in front of an item name)
+	ld a," "
+	Coorda 5, 4
+	Coorda 5, 6
+	Coorda 5, 8
+	Coorda 5, 10
+	call PlaceUnfilledArrowMenuCursor
+	xor a
+	ld [wMenuItemToSwap],a
+	ld a,[wcf91]
+	cp a,BICYCLE
+	jp z,.useOrTossItem
+.notBicycle1
+	ld a,USE_TOSS_MENU_TEMPLATE
+	ld [wTextBoxID],a
+	call DisplayTextBoxID
+	ld hl,wTopMenuItemY
+	ld a,11
+	ld [hli],a ; top menu item Y
+	ld a,14
+	ld [hli],a ; top menu item X
+	xor a
+	ld [hli],a ; current menu item ID
+	inc hl
+	inc a ; a = 1
+	ld [hli],a ; max menu item ID
+	ld a,A_BUTTON | B_BUTTON
+	ld [hli],a ; menu watched keys
+	xor a
+	ld [hl],a ; old menu item id
+	call HandleMenuInput
+	call PlaceUnfilledArrowMenuCursor
+	bit 1,a ; was the B button pressed?
+	jr z,.useOrTossItem
+	jp ItemMenuLoop
+.useOrTossItem ; if the player made the choice to use or toss the item
+	ld a,[wcf91]
+	ld [wd11e],a
+	call GetItemName
+	call CopyStringToCF50 ; copy name to wcf50
+	ld a,[wcf91]
+	cp a,BICYCLE
+	jr nz,.notBicycle2
+	ld a,[wd732]
+	bit 5,a
+	jr z,.useItem_closeMenu
+	ld hl,CannotGetOffHereText
+	call PrintText
+	jp ItemMenuLoop
+.notBicycle2
+	ld a,[wCurrentMenuItem]
+	and a
+	jr nz,.tossItem
+; use item
+	ld [wPseudoItemID],a ; a must be 0 due to above conditional jump
+	ld a,[wcf91]
+	cp a,HM_01
+	jr nc,.useItem_partyMenu
+	ld hl,UsableItems_CloseMenu
+	ld de,1
+	call IsInArray
+	jr c,.useItem_closeMenu
+	ld a,[wcf91]
+	ld hl,UsableItems_PartyMenu
+	ld de,1
+	call IsInArray
+	jr c,.useItem_partyMenu
+	call UseItem
+	jp ItemMenuLoop
+.useItem_closeMenu
+	xor a
+	ld [wPseudoItemID],a
+	call UseItem
+	ld a,[wActionResultOrTookBattleTurn]
+	and a
+	jp z,ItemMenuLoop
+	jp CloseStartMenu
+.useItem_partyMenu
+	ld a,[wUpdateSpritesEnabled]
+	push af
+	call UseItem
+	ld a,[wActionResultOrTookBattleTurn]
+	cp a,$02
+	jp z,.partyMenuNotDisplayed
+	call GBPalWhiteOutWithDelay3
+	call RestoreScreenTilesAndReloadTilePatterns
+	pop af
+	ld [wUpdateSpritesEnabled],a
+	jp StartMenu_Item
+.partyMenuNotDisplayed
+	pop af
+	ld [wUpdateSpritesEnabled],a
+	jp ItemMenuLoop
+.tossItem
+	call IsKeyItem
+	ld a,[wIsKeyItem]
+	and a
+	jr nz,.skipAskingQuantity
+	ld a,[wcf91]
+	call IsItemHM
+	jr c,.skipAskingQuantity
+	call DisplayChooseQuantityMenu
+	inc a
+	jr z,.tossZeroItems
+.skipAskingQuantity
+	ld hl,wNumBagItems
+	call TossItem
+.tossZeroItems
+	jp ItemMenuLoop
+
+CannotUseItemsHereText:
+	TX_FAR _CannotUseItemsHereText
+	db "@"
+
+CannotGetOffHereText:
+	TX_FAR _CannotGetOffHereText
+	db "@"
+
+; items which bring up the party menu when used
+UsableItems_PartyMenu:
+	db MOON_STONE
+	db ANTIDOTE
+	db BURN_HEAL
+	db ICE_HEAL
+	db AWAKENING
+	db PARLYZ_HEAL
+	db FULL_RESTORE
+	db MAX_POTION
+	db HYPER_POTION
+	db SUPER_POTION
+	db POTION
+	db FIRE_STONE
+	db THUNDER_STONE
+	db WATER_STONE
+	db HP_UP
+	db PROTEIN
+	db IRON
+	db CARBOS
+	db CALCIUM
+	db RARE_CANDY
+	db LEAF_STONE
+	db FULL_HEAL
+	db REVIVE
+	db MAX_REVIVE
+	db FRESH_WATER
+	db SODA_POP
+	db LEMONADE
+	db X_ATTACK
+	db X_DEFEND
+	db X_SPEED
+	db X_SPECIAL
+	db PP_UP
+	db ETHER
+	db MAX_ETHER
+	db ELIXER
+	db MAX_ELIXER
+	db $ff
+
+; items which close the item menu when used
+UsableItems_CloseMenu:
+	db ESCAPE_ROPE
+	db ITEMFINDER
+	db POKE_FLUTE
+	db OLD_ROD
+	db GOOD_ROD
+	db SUPER_ROD
+	db $ff
+
+StartMenu_TrainerInfo:
+	call GBPalWhiteOut
+	call ClearScreen
+	call UpdateSprites
+	ld a,[hTilesetType]
+	push af
+	xor a
+	ld [hTilesetType],a
+	call DrawTrainerInfo
+	predef DrawBadges ; draw badges
+	ld b, SET_PAL_TRAINER_CARD
+	call RunPaletteCommand
+	call GBPalNormal
+	call WaitForTextScrollButtonPress ; wait for button press
+	call GBPalWhiteOut
+	call LoadFontTilePatterns
+	call LoadScreenTilesFromBuffer2 ; restore saved screen
+	call RunDefaultPaletteCommand
+	call ReloadMapData
+	call LoadGBPal
+	pop af
+	ld [hTilesetType],a
+	jp RedisplayStartMenu
+
+; loads tile patterns and draws everything except for gym leader faces / badges
+DrawTrainerInfo:
+	ld de,RedPicFront
+	lb bc, BANK(RedPicFront), $01
+	predef DisplayPicCenteredOrUpperRight
+	call DisableLCD
+	coord hl, 0, 2
+	ld a," "
+	call TrainerInfo_DrawVerticalLine
+	coord hl, 1, 2
+	call TrainerInfo_DrawVerticalLine
+	ld hl,vChars2 + $70
+	ld de,vChars2
+	ld bc,$70 * 4
+	call CopyData
+	ld hl,TrainerInfoTextBoxTileGraphics ; trainer info text box tile patterns
+	ld de,vChars2 + $770
+	ld bc,$0080
+	push bc
+	call TrainerInfo_FarCopyData
+	ld hl,BlankLeaderNames
+	ld de,vChars2 + $600
+	ld bc,$0170
+	call TrainerInfo_FarCopyData
+	pop bc
+	ld hl,BadgeNumbersTileGraphics  ; badge number tile patterns
+	ld de,vChars1 + $580
+	call TrainerInfo_FarCopyData
+	ld hl,GymLeaderFaceAndBadgeTileGraphics  ; gym leader face and badge tile patterns
+	ld de,vChars2 + $200
+	ld bc,$0400
+	ld a,$03
+	call FarCopyData2
+	ld hl,TextBoxGraphics
+	ld de,$00d0
+	add hl,de ; hl = colon tile pattern
+	ld de,vChars1 + $560
+	ld bc,$0010
+	ld a,$04
+	push bc
+	call FarCopyData2
+	pop bc
+	ld hl,TrainerInfoTextBoxTileGraphics + $80  ; background tile pattern
+	ld de,vChars1 + $570
+	call TrainerInfo_FarCopyData
+	call EnableLCD
+	ld hl,wTrainerInfoTextBoxWidthPlus1
+	ld a,18 + 1
+	ld [hli],a
+	dec a
+	ld [hli],a
+	ld [hl],1
+	coord hl, 0, 0
+	call TrainerInfo_DrawTextBox
+	ld hl,wTrainerInfoTextBoxWidthPlus1
+	ld a,16 + 1
+	ld [hli],a
+	dec a
+	ld [hli],a
+	ld [hl],3
+	coord hl, 1, 10
+	call TrainerInfo_DrawTextBox
+	coord hl, 0, 10
+	ld a,$d7
+	call TrainerInfo_DrawVerticalLine
+	coord hl, 19, 10
+	call TrainerInfo_DrawVerticalLine
+	coord hl, 6, 9
+	ld de,TrainerInfo_BadgesText
+	call PlaceString
+	coord hl, 2, 2
+	ld de,TrainerInfo_NameMoneyTimeText
+	call PlaceString
+	coord hl, 7, 2
+	ld de,wPlayerName
+	call PlaceString
+	coord hl, 8, 4
+	ld de,wPlayerMoney
+	ld c,$e3
+	call PrintBCDNumber
+	coord hl, 9, 6
+	ld de,wPlayTimeHours ; hours
+	lb bc, LEFT_ALIGN | 1, 3
+	call PrintNumber
+	ld [hl],$d6 ; colon tile ID
+	inc hl
+	ld de,wPlayTimeMinutes ; minutes
+	lb bc, LEADING_ZEROES | 1, 2
+	jp PrintNumber
+
+TrainerInfo_FarCopyData:
+	ld a,BANK(TrainerInfoTextBoxTileGraphics)
+	jp FarCopyData2
+
+TrainerInfo_NameMoneyTimeText:
+	db   "NAME/"
+	next "GELD/"
+	next "ZEIT/@"
+
+; $76 is a circle tile
+TrainerInfo_BadgesText:
+	db $76,"ORDEN",$76,"@"
+
+; draws a text box on the trainer info screen
+; height is always 6
+; INPUT:
+; hl = destination address
+; [wTrainerInfoTextBoxWidthPlus1] = width
+; [wTrainerInfoTextBoxWidth] = width - 1
+; [wTrainerInfoTextBoxNextRowOffset] = distance from the end of a text box row to the start of the next
+TrainerInfo_DrawTextBox:
+	ld a,$79 ; upper left corner tile ID
+	lb de, $7a, $7b ; top edge and upper right corner tile ID's
+	call TrainerInfo_DrawHorizontalEdge ; draw top edge
+	call TrainerInfo_NextTextBoxRow
+	ld a,[wTrainerInfoTextBoxWidthPlus1]
+	ld e,a
+	ld d,0
+	ld c,6 ; height of the text box
+.loop
+	ld [hl],$7c ; left edge tile ID
+	add hl,de
+	ld [hl],$78 ; right edge tile ID
+	call TrainerInfo_NextTextBoxRow
+	dec c
+	jr nz,.loop
+	ld a,$7d ; lower left corner tile ID
+	lb de,$77, $7e ; bottom edge and lower right corner tile ID's
+
+TrainerInfo_DrawHorizontalEdge:
+	ld [hli],a ; place left corner tile
+	ld a,[wTrainerInfoTextBoxWidth]
+	ld c,a
+	ld a,d
+.loop
+	ld [hli],a ; place edge tile
+	dec c
+	jr nz,.loop
+	ld a,e
+	ld [hl],a ; place right corner tile
+	ret
+
+TrainerInfo_NextTextBoxRow:
+	ld a,[wTrainerInfoTextBoxNextRowOffset] ; distance to the start of the next row
+.loop
+	inc hl
+	dec a
+	jr nz,.loop
+	ret
+
+; draws a vertical line
+; INPUT:
+; hl = address of top tile in the line
+; a = tile ID
+TrainerInfo_DrawVerticalLine:
+	ld de,SCREEN_WIDTH
+	ld c,8
+.loop
+	ld [hl],a
+	add hl,de
+	dec c
+	jr nz,.loop
+	ret
+
+StartMenu_SaveReset:
+	ld a,[wd72e]
+	bit 6,a ; is the player using the link feature?
+	jp nz,Init
+	predef SaveSAV ; save the game
+	call LoadScreenTilesFromBuffer2 ; restore saved screen
+	jp HoldTextDisplayOpen
+
+StartMenu_Option:
+	xor a
+	ld [H_AUTOBGTRANSFERENABLED],a
+	call ClearScreen
+	call UpdateSprites
+	callab DisplayOptionMenu
+	call LoadScreenTilesFromBuffer2 ; restore saved screen
+	call LoadTextBoxTilePatterns
+	call UpdateSprites
+	jp RedisplayStartMenu
+
+SwitchPartyMon:
+	call SwitchPartyMon_InitVarOrSwapData ; swap data
+	ld a, [wSwappedMenuItem]
+	call SwitchPartyMon_ClearGfx
+	ld a, [wCurrentMenuItem]
+	call SwitchPartyMon_ClearGfx
+	jp RedrawPartyMenu_
+
+SwitchPartyMon_ClearGfx:
+	push af
+	coord hl, 0, 0
+	ld bc, SCREEN_WIDTH * 2
+	call AddNTimes
+	ld c, SCREEN_WIDTH * 2
+	ld a, " "
+.clearMonBGLoop ; clear the mon's row in the party menu
+	ld [hli], a
+	dec c
+	jr nz, .clearMonBGLoop
+	pop af
+	ld hl, wOAMBuffer
+	ld bc, $10
+	call AddNTimes
+	ld de, $4
+	ld c, e
+.clearMonOAMLoop
+	ld [hl], $a0
+	add hl, de
+	dec c
+	jr nz, .clearMonOAMLoop
+	call WaitForSoundToFinish
+	ld a, SFX_SWAP
+	jp PlaySound
+
+SwitchPartyMon_InitVarOrSwapData:
+; This is used to initialise [wMenuItemToSwap] and to actually swap the data.
+	ld a, [wMenuItemToSwap]
+	and a ; has [wMenuItemToSwap] been initialised yet?
+	jr nz, .pickedMonsToSwap
+; If not, initialise [wMenuItemToSwap] so that it matches the current mon.
+	ld a, [wWhichPokemon]
+	inc a ; [wMenuItemToSwap] counts from 1
+	ld [wMenuItemToSwap], a
+	ret
+.pickedMonsToSwap
+	xor a
+	ld [wPartyMenuTypeOrMessageID], a
+	ld a, [wMenuItemToSwap]
+	dec a
+	ld b, a
+	ld a, [wCurrentMenuItem]
+	ld [wSwappedMenuItem], a
+	cp b ; swapping a mon with itself?
+	jr nz, .swappingDifferentMons
+; can't swap a mon with itself
+	xor a
+	ld [wMenuItemToSwap], a
+	ld [wPartyMenuTypeOrMessageID], a
+	ret
+.swappingDifferentMons
+	ld a, b
+	ld [wMenuItemToSwap], a
+	push hl
+	push de
+	ld hl, wPartySpecies
+	ld d, h
+	ld e, l
+	ld a, [wCurrentMenuItem]
+	add l
+	ld l, a
+	jr nc, .noCarry
+	inc h
+.noCarry
+	ld a, [wMenuItemToSwap]
+	add e
+	ld e, a
+	jr nc, .noCarry2
+	inc d
+.noCarry2
+	ld a, [hl]
+	ld [hSwapTemp], a
+	ld a, [de]
+	ld [hl], a
+	ld a, [hSwapTemp]
+	ld [de], a
+	ld hl, wPartyMons
+	ld bc, wPartyMon2 - wPartyMon1
+	ld a, [wCurrentMenuItem]
+	call AddNTimes
+	push hl
+	ld de, wSwitchPartyMonTempBuffer
+	ld bc, wPartyMon2 - wPartyMon1
+	call CopyData
+	ld hl, wPartyMons
+	ld bc, wPartyMon2 - wPartyMon1
+	ld a, [wMenuItemToSwap]
+	call AddNTimes
+	pop de
+	push hl
+	ld bc, wPartyMon2 - wPartyMon1
+	call CopyData
+	pop de
+	ld hl, wSwitchPartyMonTempBuffer
+	ld bc, wPartyMon2 - wPartyMon1
+	call CopyData
+	ld hl, wPartyMonOT
+	ld a, [wCurrentMenuItem]
+	call SkipFixedLengthTextEntries
+	push hl
+	ld de, wSwitchPartyMonTempBuffer
+	ld bc, NAME_LENGTH
+	call CopyData
+	ld hl, wPartyMonOT
+	ld a, [wMenuItemToSwap]
+	call SkipFixedLengthTextEntries
+	pop de
+	push hl
+	ld bc, NAME_LENGTH
+	call CopyData
+	pop de
+	ld hl, wSwitchPartyMonTempBuffer
+	ld bc, NAME_LENGTH
+	call CopyData
+	ld hl, wPartyMonNicks
+	ld a, [wCurrentMenuItem]
+	call SkipFixedLengthTextEntries
+	push hl
+	ld de, wSwitchPartyMonTempBuffer
+	ld bc, NAME_LENGTH
+	call CopyData
+	ld hl, wPartyMonNicks
+	ld a, [wMenuItemToSwap]
+	call SkipFixedLengthTextEntries
+	pop de
+	push hl
+	ld bc, NAME_LENGTH
+	call CopyData
+	pop de
+	ld hl, wSwitchPartyMonTempBuffer
+	ld bc, NAME_LENGTH
+	call CopyData
+	ld a, [wMenuItemToSwap]
+	ld [wSwappedMenuItem], a
+	xor a
+	ld [wMenuItemToSwap], a
+	ld [wPartyMenuTypeOrMessageID], a
+	pop de
+	pop hl
+	ret