more movement stuff

engine/overworld/movement.asm

@@ -188,7 +188,7 @@ UpdateNPCSprite: ; 4ed1 (1:4ed1)
 	call LoadDEPlusA ; a = [wNPCMovementDirections + $fe] (?)
 	jr .determineDirection
 .randomMovement
-	call getTileSpriteStandsOn
+	call GetTileSpriteStandsOn
 	call Random
 .determineDirection
 	ld b, a
@@ -504,7 +504,7 @@ CheckSpriteAvailability: ; 50dc (1:50dc)
 .skipXVisibilityTest
 ; make the sprite invisible if a text box is in front of it
 ; $5F is the maximum number for map tiles
-	call getTileSpriteStandsOn
+	call GetTileSpriteStandsOn
 	ld d, $60
 	ld a, [hli]
 	cp d
@@ -685,7 +685,7 @@ CanWalkOntoTile: ; 516e (1:516e)
 ; calculates the tile pointer pointing to the tile the current sprite stancs on
 ; this is always the lower left tile of the 2x2 tile blocks all sprites are snapped to
 ; hl: output pointer
-getTileSpriteStandsOn: ; 5207 (1:5207)
+GetTileSpriteStandsOn: ; 5207 (1:5207)
 	ld h, $c1
 	ld a, [H_CURRENTSPRITEOFFSET]
 	add $4
@@ -724,6 +724,10 @@ LoadDEPlusA: ; 522f (1:522f)
 	ret
 
 DoScriptedNPCMovement: ; 5236 (1:5236)
+; This is an alternative method of scripting an NPC's movement and is only used
+; a few times in the game. It is used when the NPC and player must walk together
+; in sync, such as when the player is following the NPC somewhere. An NPC can't
+; be moved in sync with the player using the other method.
 	ld a, [wd730]
 	bit 7, a
 	ret z
@@ -740,28 +744,28 @@ DoScriptedNPCMovement: ; 5236 (1:5236)
 .noCarry
 	ld a, [hl]
 ; check if moving up
-	cp $40
+	cp NPC_MOVEMENT_UP
 	jr nz, .checkIfMovingDown
 	call GetSpriteScreenYPointer
 	ld c, SPRITE_FACING_UP
 	ld a, -2
 	jr .move
 .checkIfMovingDown
-	cp $0
+	cp NPC_MOVEMENT_DOWN
 	jr nz, .checkIfMovingLeft
 	call GetSpriteScreenYPointer
 	ld c, SPRITE_FACING_DOWN
 	ld a, 2
 	jr .move
 .checkIfMovingLeft
-	cp $80
+	cp NPC_MOVEMENT_LEFT
 	jr nz, .checkIfMovingRight
 	call GetSpriteScreenXPointer
 	ld c, SPRITE_FACING_LEFT
 	ld a, -2
 	jr .move
 .checkIfMovingRight
-	cp $c0
+	cp NPC_MOVEMENT_RIGHT
 	jr nz, .noMatch
 	call GetSpriteScreenXPointer
 	ld c, SPRITE_FACING_RIGHT
@@ -781,11 +785,11 @@ DoScriptedNPCMovement: ; 5236 (1:5236)
 	ld a, c
 	ld [hl], a ; facing direction
 	call AnimScriptedNPCMovement
-	ld hl, wcf18
+	ld hl, wScriptedNPCWalkCounter
 	dec [hl]
 	ret nz
-	ld a, $8
+	ld a, 8
-	ld [wcf18], a
+	ld [wScriptedNPCWalkCounter], a
 	ld hl, wNPCMovementDirections2Index
 	inc [hl]
 	ret
@@ -793,8 +797,8 @@ DoScriptedNPCMovement: ; 5236 (1:5236)
 InitScriptedNPCMovement: ; 52a6 (1:52a6)
 	xor a
 	ld [wNPCMovementDirections2Index], a
-	ld a, $8
+	ld a, 8
-	ld [wcf18], a
+	ld [wScriptedNPCWalkCounter], a
 	jp AnimScriptedNPCMovement
 
 GetSpriteScreenYPointer: ; 52b2 (1:52b2)

engine/overworld/npc_movement.asm

@@ -44,22 +44,25 @@ _EndNPCMovementScript: ; 1a41d (6:641d)
 	ld [wSimulatedJoypadStatesEnd], a
 	ret
 
-ProfOakMovementScriptPointerTable: ; 1a442 (6:6442)
+PalletMovementScriptPointerTable: ; 1a442 (6:6442)
-	dw Func_1a44c
+	dw PalletMovementScript_OakMoveLeft
-	dw Func_1a485
+	dw PalletMovementScript_PlayerMoveLeft
-	dw Func_1a4a1
+	dw PalletMovementScript_WaitAndWalkToLab
-	dw Func_1a4a6
+	dw PalletMovementScript_WalkToLab
-	dw Func_1a4f4
+	dw PalletMovementScript_Done
 
-Func_1a44c: ; 1a44c (6:644c)
+PalletMovementScript_OakMoveLeft: ; 1a44c (6:644c)
 	ld a, [W_XCOORD]
 	sub $a
-	ld [wcca1], a
+	ld [wNumStepsToTake], a
-	jr z, .asm_1a475
+	jr z, .playerOnLeftTile
-	ld b, $0
+; The player is on the right tile of the northern path out of Pallet Town and
+; Prof. Oak is below.
+; Make Prof. Oak step to the left.
+	ld b, 0
 	ld c, a
 	ld hl, wNPCMovementDirections2
-	ld a, $80
+	ld a, NPC_MOVEMENT_LEFT
 	call FillMemory
 	ld [hl], $ff
 	ld a, [wSpriteIndex]
@@ -68,36 +71,39 @@ Func_1a44c: ; 1a44c (6:644c)
 	call MoveSprite
 	ld a, $1
 	ld [wNPCMovementScriptFunctionNum], a
-	jr .asm_1a47a
+	jr .done
-.asm_1a475
+; The player is on the left tile of the northern path out of Pallet Town and
+; Prof. Oak is below.
+; Prof. Oak is already on the right tile.
+.playerOnLeftTile
 	ld a, $3
 	ld [wNPCMovementScriptFunctionNum], a
-.asm_1a47a
+.done
 	ld hl, W_FLAGS_D733
 	set 1, [hl]
 	ld a, $fc
 	ld [wJoyIgnore], a
 	ret
 
-Func_1a485: ; 1a485 (6:6485)
+PalletMovementScript_PlayerMoveLeft: ; 1a485 (6:6485)
 	ld a, [wd730]
-	bit 0, a
+	bit 0, a ; is an NPC being moved by a script?
-	ret nz
+	ret nz ; return if Oak is still moving
-	ld a, [wcca1]
+	ld a, [wNumStepsToTake]
 	ld [wSimulatedJoypadStatesIndex], a
-	ld [$ff95], a
+	ld [hNPCMovementDirections2Index], a
 	predef ConvertNPCMovementDirectionsToJoypadMasks
 	call StartSimulatingJoypadStates
 	ld a, $2
 	ld [wNPCMovementScriptFunctionNum], a
 	ret
 
-Func_1a4a1: ; 1a4a1 (6:64a1)
+PalletMovementScript_WaitAndWalkToLab: ; 1a4a1 (6:64a1)
 	ld a, [wSimulatedJoypadStatesIndex]
-	and a
+	and a ; is the player done moving left yet?
 	ret nz
 
-Func_1a4a6: ; 1a4a6 (6:64a6)
+PalletMovementScript_WalkToLab: ; 1a4a6 (6:64a6)
 	xor a
 	ld [wOverrideSimulatedJoypadStatesMask], a
 	ld a, [wSpriteIndex]
@@ -122,12 +128,12 @@ Func_1a4a6: ; 1a4a6 (6:64a6)
 	ret
 
 RLEList_ProfOakWalkToLab: ; 1a4dc (6:64dc)
-	db $00, $05
+	db NPC_MOVEMENT_DOWN, $05
-	db $80, $01
+	db NPC_MOVEMENT_LEFT, $01
-	db $00, $05
+	db NPC_MOVEMENT_DOWN, $05
-	db $C0, $03
+	db NPC_MOVEMENT_RIGHT, $03
-	db $40, $01
+	db NPC_MOVEMENT_UP, $01
-	db $E0, $01
+	db $E0, $01 ; stand still
 	db $FF
 
 RLEList_PlayerWalkToLab: ; 1a4e9 (6:64e9)
@@ -138,7 +144,7 @@ RLEList_PlayerWalkToLab: ; 1a4e9 (6:64e9)
 	db D_DOWN, $06
 	db $FF
 
-Func_1a4f4: ; 1a4f4 (6:64f4)
+PalletMovementScript_Done: ; 1a4f4 (6:64f4)
 	ld a, [wSimulatedJoypadStatesIndex]
 	and a
 	ret nz
@@ -152,10 +158,10 @@ Func_1a4f4: ; 1a4f4 (6:64f4)
 	jp EndNPCMovementScript
 
 PewterMuseumGuyMovementScriptPointerTable: ; 1a510 (6:6510)
-	dw Func_1a514
+	dw PewterMovementScript_WalkToMuseum
-	dw PewterMovementScriptDone
+	dw PewterMovementScript_Done
 
-Func_1a514: ; 1a514 (6:6514)
+PewterMovementScript_WalkToMuseum: ; 1a514 (6:6514)
 	ld a, BANK(Music_MuseumGuy)
 	ld [wc0ef], a
 	ld [wc0f0], a
@@ -191,13 +197,13 @@ RLEList_PewterMuseumPlayer: ; 1a559 (6:6559)
 	db $FF
 
 RLEList_PewterMuseumGuy: ; 1a562 (6:6562)
-	db $40, $06
+	db NPC_MOVEMENT_UP, $06
-	db $80, $0D
+	db NPC_MOVEMENT_LEFT, $0D
-	db $40, $03
+	db NPC_MOVEMENT_UP, $03
-	db $80, $01
+	db NPC_MOVEMENT_LEFT, $01
 	db $FF
 
-PewterMovementScriptDone: ; 1a56b (6:656b)
+PewterMovementScript_Done: ; 1a56b (6:656b)
 	ld a, [wSimulatedJoypadStatesIndex]
 	and a
 	ret nz
@@ -208,10 +214,10 @@ PewterMovementScriptDone: ; 1a56b (6:656b)
 	jp EndNPCMovementScript
 
 PewterGymGuyMovementScriptPointerTable: ; 1a57d (6:657d)
-	dw Func_1a581
+	dw PewterMovementScript_WalkToGym
-	dw PewterMovementScriptDone
+	dw PewterMovementScript_Done
 
-Func_1a581: ; 1a581 (6:6581)
+PewterMovementScript_WalkToGym: ; 1a581 (6:6581)
 	ld a, BANK(Music_MuseumGuy)
 	ld [wc0ef], a
 	ld [wc0f0], a
@@ -252,12 +258,12 @@ RLEList_PewterGymPlayer: ; 1a5cd (6:65cd)
 	db $FF
 
 RLEList_PewterGymGuy: ; 1a5da (6:65da)
-	db $00, $02
+	db NPC_MOVEMENT_DOWN, $02
-	db $80, $0F
+	db NPC_MOVEMENT_LEFT, $0F
-	db $40, $05
+	db NPC_MOVEMENT_UP, $05
-	db $80, $0B
+	db NPC_MOVEMENT_LEFT, $0B
-	db $00, $05
+	db NPC_MOVEMENT_DOWN, $05
-	db $C0, $03
+	db NPC_MOVEMENT_RIGHT, $03
 	db $FF
 
 FreezeEnemyTrainerSprite: ; 1a5e7 (6:65e7)

engine/overworld/oam.asm

@@ -16,10 +16,10 @@ PrepareOAMData:
 	ld [hOAMBufferOffset], a
 
 .spriteLoop
-	ld [hSpriteDataOffset2], a
+	ld [hSpriteOffset2], a
 
 	ld d, wSpriteStateData1 / $100
-	ld a, [hSpriteDataOffset2]
+	ld a, [hSpriteOffset2]
 	ld e, a
 	ld a, [de] ; c1x0
 	and a
@@ -139,7 +139,7 @@ PrepareOAMData:
 	ld [hOAMBufferOffset], a
 
 .nextSprite
-	ld a, [hSpriteDataOffset2]
+	ld a, [hSpriteOffset2]
 	add $10
 	cp $100 % $100
 	jp nz, .spriteLoop

home.asm

@@ -2195,7 +2195,7 @@ RunNPCMovementScript:: ; 310e (0:310e)
 	ld [MBC1RomBank], a
 	ret
 .NPCMovementScriptPointerTables
-	dw ProfOakMovementScriptPointerTable
+	dw PalletMovementScriptPointerTable
 	dw PewterMuseumGuyMovementScriptPointerTable
 	dw PewterGymGuyMovementScriptPointerTable
 .playerStepOutFromDoor
@@ -3078,7 +3078,7 @@ MoveSprite_:: ; 363d (0:363d)
 	ld [wWastedByteCD3A],a
 	ret
 
-; divides [$ffe5] by [$ffe6] and stores the quotient in [$ffe7]
+; divides [hDividend2] by [hDivisor2] and stores the quotient in [hQuotient2]
 DivideBytes:: ; 366b (0:366b)
 	push hl
 	ld hl, $ffe7

hram.asm

@@ -28,7 +28,7 @@ hPartyMonIndex EQU $FF8C
 
 hHalveItemPrices EQU $FF8E
 
-hSpriteDataOffset2 EQU $FF8F
+hSpriteOffset2 EQU $FF8F
 
 hOAMBufferOffset EQU $FF90
 
@@ -39,6 +39,11 @@ hTilePlayerStandingOn EQU $FF93
 
 hSpritePriority EQU $FF94
 
+hNPCMovementDirections2Index EQU $FF95
+
+; CalcPositionOfPlayerRelativeToNPC
+hNPCSpriteOffset EQU $FF95
+
 ; Multiplcation and division variables are meant
 ; to overlap for back-to-back usage. Big endian.
 
@@ -57,6 +62,33 @@ H_NUMTOPRINT        EQU $FF96 ; 3 bytes
 H_POWEROFTEN        EQU $FF99 ; 3 bytes
 H_SAVEDNUMTOPRINT   EQU $FF9C ; 3 bytes
 
+; distance in steps between NPC and player
+hNPCPlayerYDistance EQU $FF95
+hNPCPlayerXDistance EQU $FF96
+
+hFindPathNumSteps EQU $FF97
+
+; bit 0: set when the end of the path's Y coordinate matches the target's
+; bit 1: set when the end of the path's X coordinate matches the target's
+; When both bits are set, the end of the path is at the target's position
+; (i.e. the path has been found).
+hFindPathFlags EQU $FF98
+
+hFindPathYProgress EQU $FF99
+hFindPathXProgress EQU $FF9A
+
+; 0 = from player to NPC
+; 1 = from NPC to player
+hNPCPlayerRelativePosPerspective EQU $FF9B
+
+; bit 0:
+; 0 = target is to the south or aligned
+; 1 = target is to the north
+; bit 1:
+; 0 = target is to the east or aligned
+; 1 = target is to the west
+hNPCPlayerRelativePosFlags EQU $FF9D
+
 hSerialReceivedNewData EQU $FFA9
 
 ; $01 = using external clock
@@ -166,6 +198,10 @@ hTilesetType EQU $FFD7
 
 H_CURRENTSPRITEOFFSET EQU $FFDA ; multiple of $10
 
+hDividend2 EQU $FFE5
+hDivisor2  EQU $FFE6
+hQuotient2 EQU $FFE7
+
 hSpriteVRAMSlotAndFacing EQU $FFE9
 
 hSpriteAnimFrameCounter EQU $FFEA

main.asm

@@ -4521,72 +4521,75 @@ IsItemInBag_: ; f8a5 (3:78a5)
 
 FindPathToPlayer: ; f8ba (3:78ba)
 	xor a
-	ld hl, $ff97
+	ld hl, hFindPathNumSteps
-	ld [hli], a
+	ld [hli], a ; hFindPathNumSteps
-	ld [hli], a
+	ld [hli], a ; hFindPathFlags
-	ld [hli], a
+	ld [hli], a ; hFindPathYProgress
-	ld [hl], a
+	ld [hl], a  ; hFindPathXProgress
 	ld hl, wNPCMovementDirections2
 	ld de, $0
 .loop
-	ld a, [$ff99]
+	ld a, [hFindPathYProgress]
 	ld b, a
-	ld a, [$ff95] ; Y distance in steps
+	ld a, [hNPCPlayerYDistance] ; Y distance in steps
 	call CalcDifference
 	ld d, a
 	and a
 	jr nz, .asm_f8da
-	ld a, [$ff98]
+	ld a, [hFindPathFlags]
-	set 0, a
+	set 0, a ; current end of path matches the player's Y coordinate
-	ld [$ff98], a
+	ld [hFindPathFlags], a
 .asm_f8da
-	ld a, [$ff9a]
+	ld a, [hFindPathXProgress]
 	ld b, a
-	ld a, [$ff96] ; X distance in steps
+	ld a, [hNPCPlayerXDistance] ; X distance in steps
 	call CalcDifference
 	ld e, a
 	and a
 	jr nz, .asm_f8ec
-	ld a, [$ff98]
+	ld a, [hFindPathFlags]
-	set 1, a
+	set 1, a ; current end of path matches the player's X coordinate
-	ld [$ff98], a
+	ld [hFindPathFlags], a
 .asm_f8ec
-	ld a, [$ff98]
+	ld a, [hFindPathFlags]
-	cp $3
+	cp $3 ; has the end of the path reached the player's position?
 	jr z, .done
+; Compare whether the X distance between the player and the current of the path
+; is greater or if the Y distance is. Then, try to reduce whichever is greater.
 	ld a, e
 	cp d
-	jr c, .asm_f90a
+	jr c, .yDistanceGreater
-	ld a, [$ff9d]
+; x distance is greater
+	ld a, [hNPCPlayerRelativePosFlags]
 	bit 1, a
-	jr nz, .asm_f900
+	jr nz, .playerIsLeftOfNPC
 	ld d, NPC_MOVEMENT_RIGHT
-	jr .asm_f902
+	jr .next1
-.asm_f900
+.playerIsLeftOfNPC
 	ld d, NPC_MOVEMENT_LEFT
-.asm_f902
+.next1
-	ld a, [$ff9a]
+	ld a, [hFindPathXProgress]
-	add $1
+	add 1
-	ld [$ff9a], a
+	ld [hFindPathXProgress], a
-	jr .asm_f91c
+	jr .storeDirection
-.asm_f90a
+.yDistanceGreater
-	ld a, [$ff9d]
+	ld a, [hNPCPlayerRelativePosFlags]
 	bit 0, a
-	jr nz, .asm_f914
+	jr nz, .playerIsAboveNPC
 	ld d, NPC_MOVEMENT_DOWN
-	jr .asm_f916
+	jr .next2
-.asm_f914
+.playerIsAboveNPC
 	ld d, NPC_MOVEMENT_UP
-.asm_f916
+.next2
-	ld a, [$ff99]
+	ld a, [hFindPathYProgress]
-	add $1
+	add 1
-	ld [$ff99], a
+	ld [hFindPathYProgress], a
-.asm_f91c
+.storeDirection
 	ld a, d
 	ld [hli], a
-	ld a, [$ff97]
+	ld a, [hFindPathNumSteps]
 	inc a
-	ld [$ff97], a
+	ld [hFindPathNumSteps], a
 	jp .loop
 .done
 	ld [hl], $ff
@@ -4594,13 +4597,13 @@ FindPathToPlayer: ; f8ba (3:78ba)
 
 CalcPositionOfPlayerRelativeToNPC: ; f929 (3:7929)
 	xor a
-	ld [$ff9d], a
+	ld [hNPCPlayerRelativePosFlags], a
 	ld a, [wSpriteStateData1 + 4] ; player's sprite screen Y position in pixels
 	ld d, a
 	ld a, [wSpriteStateData1 + 6] ; player's sprite screen X position in pixels
 	ld e, a
 	ld hl, wSpriteStateData1
-	ld a, [$ff95] ; sprite offset
+	ld a, [hNPCSpriteOffset]
 	add l
 	add $4
 	ld l, a
@@ -4614,26 +4617,26 @@ CalcPositionOfPlayerRelativeToNPC: ; f929 (3:7929)
 	jr nc, .NPCSouthOfOrAlignedWithPlayer
 .NPCNorthOfPlayer
 	push hl
-	ld hl, $ff9d
+	ld hl, hNPCPlayerRelativePosFlags
 	bit 0, [hl]
 	set 0, [hl]
 	pop hl
 	jr .divideYDistance
 .NPCSouthOfOrAlignedWithPlayer
 	push hl
-	ld hl, $ff9d
+	ld hl, hNPCPlayerRelativePosFlags
 	bit 0, [hl]
 	res 0, [hl]
 	pop hl
 .divideYDistance
 	push hl
-	ld hl, $ffe5
+	ld hl, hDividend2
 	ld [hli], a
 	ld a, 16
 	ld [hli], a
 	call DivideBytes ; divide Y absolute distance by 16
 	ld a, [hl] ; quotient
-	ld [$ff95], a
+	ld [hNPCPlayerYDistance], a
 	pop hl
 	inc hl
 	ld b, e
@@ -4642,35 +4645,35 @@ CalcPositionOfPlayerRelativeToNPC: ; f929 (3:7929)
 	jr nc, .NPCEastOfOrAlignedWithPlayer
 .NPCWestOfPlayer
 	push hl
-	ld hl, $ff9d
+	ld hl, hNPCPlayerRelativePosFlags
 	bit 1, [hl]
 	set 1, [hl]
 	pop hl
 	jr .divideXDistance
 .NPCEastOfOrAlignedWithPlayer
 	push hl
-	ld hl, $ff9d
+	ld hl, hNPCPlayerRelativePosFlags
 	bit 1, [hl]
 	res 1, [hl]
 	pop hl
 .divideXDistance
-	ld [$ffe5], a
+	ld [hDividend2], a
 	ld a, 16
-	ld [$ffe6], a
+	ld [hDivisor2], a
 	call DivideBytes ; divide X absolute distance by 16
-	ld a, [$ffe7] ; quotient
+	ld a, [hQuotient2]
-	ld [$ff96], a
+	ld [hNPCPlayerXDistance], a
-	ld a, [$ff9b]
+	ld a, [hNPCPlayerRelativePosPerspective]
 	and a
 	ret z
-	ld a, [$ff9d]
+	ld a, [hNPCPlayerRelativePosFlags]
 	cpl
 	and $3
-	ld [$ff9d], a
+	ld [hNPCPlayerRelativePosFlags], a
 	ret
 
 ConvertNPCMovementDirectionsToJoypadMasks: ; f9a0 (3:79a0)
-	ld a, [$ff95]
+	ld a, [hNPCMovementDirections2Index]
 	ld [wNPCMovementDirections2Index], a
 	dec a
 	ld de, wSimulatedJoypadStatesEnd
@@ -4684,9 +4687,9 @@ ConvertNPCMovementDirectionsToJoypadMasks: ; f9a0 (3:79a0)
 	call ConvertNPCMovementDirectionToJoypadMask
 	ld [de], a
 	inc de
-	ld a, [$ff95]
+	ld a, [hNPCMovementDirections2Index]
 	dec a
-	ld [$ff95], a
+	ld [hNPCMovementDirections2Index], a
 	jr nz, .loop
 	ret
 

scripts/oakslab.asm

@@ -333,14 +333,14 @@ OaksLabScript10: ; 1cd6d (7:4d6d)
 	ld [$ff8c], a
 	call DisplayTextID
 	ld a, $1
-	ld [$ff9b], a
+	ld [hNPCPlayerRelativePosPerspective], a
 	ld a, $1
 	swap a
-	ld [$ff95], a
+	ld [hNPCSpriteOffset], a
 	predef CalcPositionOfPlayerRelativeToNPC
-	ld a, [$ff95]
+	ld a, [hNPCPlayerYDistance]
 	dec a
-	ld [$ff95], a
+	ld [hNPCPlayerYDistance], a
 	predef FindPathToPlayer
 	ld de, wNPCMovementDirections2
 	ld a, $1

scripts/pallettown.asm

@@ -33,7 +33,7 @@ PalletTownScript0: ; 18e81 (6:4e81)
 	ld a,$FF
 	call PlaySound ; stop music
 	ld a, BANK(Music_MeetProfOak)
-	ld c,a ; song bank
+	ld c,a
 	ld a, MUSIC_MEET_PROF_OAK ; “oak appears” music
 	call PlayMusic
 	ld a,$FC
@@ -50,7 +50,7 @@ PalletTownScript1: ; 18eb2 (6:4eb2)
 	xor a
 	ld [wcf0d],a
 	ld a,1
-	ld [$FF8C],a
+	ld [hSpriteIndexOrTextID],a
 	call DisplayTextID
 	ld a,$FF
 	ld [wJoyIgnore],a
@@ -65,25 +65,25 @@ PalletTownScript1: ; 18eb2 (6:4eb2)
 
 PalletTownScript2: ; 18ed2 (6:4ed2)
 	ld a,1
-	ld [$FF8C],a
+	ld [H_SPRITEINDEX],a
-	ld a,4
+	ld a,SPRITE_FACING_UP
 	ld [$FF8D],a
 	call SetSpriteFacingDirectionAndDelay
 	call Delay3
 	ld a,1
 	ld [W_YCOORD],a
 	ld a,1
-	ld [$FF9B],a
+	ld [hNPCPlayerRelativePosPerspective],a
 	ld a,1
 	swap a
-	ld [$FF95],a
+	ld [hNPCSpriteOffset],a
 	predef CalcPositionOfPlayerRelativeToNPC
-	ld hl,$FF95
+	ld hl,hNPCPlayerYDistance
 	dec [hl]
 	predef FindPathToPlayer ; load Oak’s movement into wNPCMovementDirections2
 	ld de,wNPCMovementDirections2
 	ld a,1 ; oak
-	ld [$FF8C],a
+	ld [H_SPRITEINDEX],a
 	call MoveSprite
 	ld a,$FF
 	ld [wJoyIgnore],a
@@ -104,8 +104,9 @@ PalletTownScript3: ; 18f12 (6:4f12)
 	ld a,$FC
 	ld [wJoyIgnore],a
 	ld a,1
-	ld [$FF8C],a
+	ld [hSpriteIndexOrTextID],a
 	call DisplayTextID
+; set up movement script that causes the player to follow Oak to his lab
 	ld a,$FF
 	ld [wJoyIgnore],a
 	ld a,1
@@ -124,7 +125,7 @@ PalletTownScript3: ; 18f12 (6:4f12)
 
 PalletTownScript4: ; 18f4b (6:4f4b)
 	ld a,[wNPCMovementScriptPointerTableNum]
-	and a
+	and a ; is the movement script over?
 	ret nz
 
 	; trigger the next script

wram.asm

@@ -390,7 +390,9 @@ wSwitchPartyMonTempBuffer:: ; cc97
 ; temporary buffer when swapping party mon data
 	ds 10
 
-wcca1:: ds 49 ; used in overworld npc movement
+wNumStepsToTake:: ; cca1
+; used in Pallet Town scripted movement
+	ds 49
 
 wRLEByteCount:: ; ccd2
 	ds 1
@@ -988,7 +990,10 @@ wNPCMovementScriptSpriteOffset:: ; cf17
 ; sprite offset of sprite being controlled by NPC movement script
 	ds 1
 
-wcf18:: ds 2 ; used with overworld movement
+wScriptedNPCWalkCounter:: ; cf18
+	ds 1
+
+	ds 1
 
 wGBC:: ; cf1a
 	ds 1