ref: 7b676f5851a2b6fe0001f259afde6e9918b93683
parent: 994c2cbf289efa2e23eabf1af96ba62e4f066005
author: YamaArashi <shadow962@live.com>
date: Wed Jul 15 00:27:59 EDT 2015
commented movement stuff
--- a/engine/overworld/movement.asm
+++ b/engine/overworld/movement.asm
@@ -12,7 +12,7 @@
; the maximum number for map tiles
.checkIfTextBoxInFrontOfSprite
aCoord 8, 9
- ld [$ff93], a
+ ld [hTilePlayerStandingOn], a
cp $60
jr c, .lowerLeftTileIsMapTile
.disableSprite
@@ -21,44 +21,46 @@
ret
.lowerLeftTileIsMapTile
call DetectCollisionBetweenSprites
- ld h, $c1
+ ld h, wSpriteStateData1 / $100
ld a, [wWalkCounter]
and a
- jr nz, .asm_4e90
+ jr nz, .moving
ld a, [wd528]
+; check if down
bit 2, a
- jr z, .notDown
+ jr z, .checkIfUp
xor a ; ld a, SPRITE_FACING_DOWN
- jr .done
-.notDown
+ jr .next
+.checkIfUp
bit 3, a
- jr z, .notUp
+ jr z, .checkIfLeft
ld a, SPRITE_FACING_UP
- jr .done
-.notUp
+ jr .next
+.checkIfLeft
bit 1, a
- jr z, .notLeft
+ jr z, .checkIfRight
ld a, SPRITE_FACING_LEFT
- jr .done
-.notLeft
+ jr .next
+.checkIfRight
bit 0, a
- jr z, .notRight
+ jr z, .notMoving
ld a, SPRITE_FACING_RIGHT
- jr .done
-.notRight
+ jr .next
+.notMoving
+; zero the animation counters
xor a
ld [wSpriteStateData1 + 7], a
ld [wSpriteStateData1 + 8], a
- jr .asm_4eab
-.done
- ld [wSpriteStateData1 + 9], a
+ jr .calcImageIndex
+.next
+ ld [wSpriteStateData1 + 9], a ; facing direction
ld a, [wFontLoaded]
bit 0, a
- jr nz, .notRight
-.asm_4e90
+ jr nz, .notMoving
+.moving
ld a, [wd736]
- bit 7, a
- jr nz, .asm_4eb6
+ bit 7, a ; is the player sprite spinning due to a spin tile?
+ jr nz, .skipSpriteAnim
ld a, [H_CURRENTSPRITEOFFSET]
add $7
ld l, a
@@ -65,8 +67,8 @@
ld a, [hl]
inc a
ld [hl], a
- cp $4
- jr nz, .asm_4eab
+ cp 4
+ jr nz, .calcImageIndex
xor a
ld [hl], a
inc hl
@@ -74,28 +76,32 @@
inc a
and $3
ld [hl], a
-.asm_4eab
+.calcImageIndex
ld a, [wSpriteStateData1 + 8]
ld b, a
ld a, [wSpriteStateData1 + 9]
add b
ld [wSpriteStateData1 + 2], a
-.asm_4eb6
- ld a, [$ff93]
+.skipSpriteAnim
+; If the player is standing on a grass tile, make the player's sprite have
+; lower priority than the background so that it's partially obscured by the
+; grass. Only the lower half of the sprite is permitted to have the priority
+; bit set by later logic.
+ ld a, [hTilePlayerStandingOn]
ld c, a
ld a, [W_GRASSTILE]
cp c
ld a, $0
- jr nz, .asm_4ec3
+ jr nz, .next2
ld a, $80
-.asm_4ec3
+.next2
ld [wSpriteStateData2 + $07], a
ret
-Func_4ec7: ; 4ec7 (1:4ec7)
+UnusedReadSpriteDataFunction: ; 4ec7 (1:4ec7)
push bc
push af
- ld a, [$ffda]
+ ld a, [H_CURRENTSPRITEOFFSET]
ld c, a
pop af
add c
@@ -103,7 +109,7 @@
pop bc
ret
-Func_4ed1: ; 4ed1 (1:4ed1)
+UpdateNPCSprite: ; 4ed1 (1:4ed1)
ld a, [H_CURRENTSPRITEOFFSET]
swap a
dec a
@@ -148,23 +154,25 @@
ld l, a
ld a, [hl] ; c2x6: movement byte 1
inc a
- jr z, .asm_4f59 ; value $FF
+ jr z, .randomMovement ; value $FF
inc a
- jr z, .asm_4f59 ; value $FE
+ jr z, .randomMovement ; value $FE
+; scripted movement
dec a
- ld [hl], a ; (temporarily) increment movement byte 1
+ ld [hl], a ; increment movement byte 1 (movement data index)
dec a
push hl
ld hl, wcf0f
dec [hl] ; decrement wcf0f
pop hl
- ld de, wcc5b
- call LoadDEPlusA ; a = [wcc5b + movement byte 1]
+ ld de, wNPCMovementDirections
+ call LoadDEPlusA ; a = [wNPCMovementDirections + movement byte 1]
cp $e0
jp z, ChangeFacingDirection
cp $ff
- jr nz, .asm_4f4b
- ld [hl], a ; reset movement byte 1 to initial value
+ jr nz, .next
+; reached end of wNPCMovementDirections list
+ ld [hl], a ; store $ff in movement byte 1, disabling scripted movement
ld hl, wd730
res 0, [hl]
xor a
@@ -171,17 +179,18 @@
ld [wSimulatedJoypadStatesIndex], a
ld [wWastedByteCD3A], a
ret
-.asm_4f4b
+.next
cp $fe
- jr nz, .asm_4f5f
+ jr nz, .determineDirection
+; current NPC movement data is $fe. this seems buggy
ld [hl], $1 ; set movement byte 1 to $1
- ld de, wcc5b
- call LoadDEPlusA ; a = [wcc5b + $fe] (?)
- jr .asm_4f5f
-.asm_4f59
+ ld de, wNPCMovementDirections
+ call LoadDEPlusA ; a = [wNPCMovementDirections + $fe] (?)
+ jr .determineDirection
+.randomMovement
call getTileSpriteStandsOn
call Random
-.asm_4f5f
+.determineDirection
ld b, a
ld a, [wCurSpriteMovement2]
cp $d0
@@ -199,7 +208,7 @@
cp $2
jr z, .moveLeft ; movement byte 2 = $2 only allows left or right
.moveDown
- ld de, 2*20
+ ld de, 2*SCREEN_WIDTH
add hl, de ; move tile pointer two rows down
ld de, $100
@@ -212,7 +221,7 @@
cp $2
jr z, .moveRight ; movement byte 2 = $2 only allows left or right
.moveUp
- ld de, -2*20
+ ld de, -2*SCREEN_WIDTH
add hl, de ; move tile pointer two rows up
ld de, $ff00
ld bc, $804
@@ -249,7 +258,7 @@
; c: new facing direction (0,4,8 or $c)
; d: Y movement delta (-1, 0 or 1)
; e: X movement delta (-1, 0 or 1)
-; hl: pointer to tile the sprite would wlak onto
+; hl: pointer to tile the sprite would walk onto
; set carry on failure, clears carry on success
TryWalking: ; 4fcb (1:4fcb)
push hl
@@ -470,7 +479,7 @@
ld l, a
ld a, [hl] ; c2x6: movement byte 1
cp $fe
- jr c, .skipXVisibilityTest ; movement byte 1 < $fe
+ jr c, .skipXVisibilityTest ; movement byte 1 < $fe (i.e. the sprite's movement is scripted)
ld a, [H_CURRENTSPRITEOFFSET]
add $4
ld l, a
@@ -572,10 +581,11 @@
ld l, a
ld a, [hl] ; c2x6 (movement byte 1)
cp $fe
- jr nc, .canMove ; values $fe and $ff
+ jr nc, .notScripted ; values $fe and $ff
+; always allow walking if the movement is scripted
and a
ret
-.canMove
+.notScripted
ld a, [W_TILESETCOLLISIONPTR]
ld l, a
ld a, [W_TILESETCOLLISIONPTR+1]
@@ -713,7 +723,7 @@
ld a, [de]
ret
-Func_5236: ; 5236 (1:5236)
+DoScriptedNPCMovement: ; 5236 (1:5236)
ld a, [wd730]
bit 7, a
ret z
@@ -720,46 +730,47 @@
ld hl, wd72e
bit 7, [hl]
set 7, [hl]
- jp z, Func_52a6
+ jp z, InitScriptedNPCMovement
ld hl, wNPCMovementDirections2
ld a, [wNPCMovementDirections2Index]
add l
ld l, a
- jr nc, .asm_5251
+ jr nc, .noCarry
inc h
-.asm_5251
+.noCarry
ld a, [hl]
+; check if moving up
cp $40
- jr nz, .asm_525f
- call Func_52b2
- ld c, $4
- ld a, $fe
- jr .asm_5289
-.asm_525f
+ jr nz, .checkIfMovingDown
+ call GetSpriteScreenYPointer
+ ld c, SPRITE_FACING_UP
+ ld a, -2
+ jr .move
+.checkIfMovingDown
cp $0
- jr nz, .asm_526c
- call Func_52b2
- ld c, $0
- ld a, $2
- jr .asm_5289
-.asm_526c
+ jr nz, .checkIfMovingLeft
+ call GetSpriteScreenYPointer
+ ld c, SPRITE_FACING_DOWN
+ ld a, 2
+ jr .move
+.checkIfMovingLeft
cp $80
- jr nz, .asm_5279
- call Func_52b7
- ld c, $8
- ld a, $fe
- jr .asm_5289
-.asm_5279
+ jr nz, .checkIfMovingRight
+ call GetSpriteScreenXPointer
+ ld c, SPRITE_FACING_LEFT
+ ld a, -2
+ jr .move
+.checkIfMovingRight
cp $c0
- jr nz, .asm_5286
- call Func_52b7
- ld c, $c
- ld a, $2
- jr .asm_5289
-.asm_5286
+ jr nz, .noMatch
+ call GetSpriteScreenXPointer
+ ld c, SPRITE_FACING_RIGHT
+ ld a, 2
+ jr .move
+.noMatch
cp $ff
ret
-.asm_5289
+.move
ld b, a
ld a, [hl]
add b
@@ -768,8 +779,8 @@
add $9
ld l, a
ld a, c
- ld [hl], a
- call Func_52c3
+ ld [hl], a ; facing direction
+ call AnimScriptedNPCMovement
ld hl, wcf18
dec [hl]
ret nz
@@ -779,22 +790,23 @@
inc [hl]
ret
-Func_52a6: ; 52a6 (1:52a6)
+InitScriptedNPCMovement: ; 52a6 (1:52a6)
xor a
ld [wNPCMovementDirections2Index], a
ld a, $8
ld [wcf18], a
- jp Func_52c3
+ jp AnimScriptedNPCMovement
-Func_52b2: ; 52b2 (1:52b2)
+GetSpriteScreenYPointer: ; 52b2 (1:52b2)
ld a, $4
ld b, a
- jr asm_52ba
+ jr GetSpriteScreenXYPointerCommon
-Func_52b7: ; 52b7 (1:52b7)
+GetSpriteScreenXPointer: ; 52b7 (1:52b7)
ld a, $6
ld b, a
-asm_52ba: ; 52ba (1:52ba)
+
+GetSpriteScreenXYPointerCommon: ; 52ba (1:52ba)
ld hl, wSpriteStateData1
ld a, [H_CURRENTSPRITEOFFSET]
add l
@@ -802,12 +814,12 @@
ld l, a
ret
-Func_52c3: ; 52c3 (1:52c3)
+AnimScriptedNPCMovement: ; 52c3 (1:52c3)
ld hl, wSpriteStateData2
ld a, [H_CURRENTSPRITEOFFSET]
add $e
ld l, a
- ld a, [hl]
+ ld a, [hl] ; VRAM slot
dec a
swap a
ld b, a
@@ -815,47 +827,47 @@
ld a, [H_CURRENTSPRITEOFFSET]
add $9
ld l, a
- ld a, [hl]
- cp $0
- jr z, .asm_52ea
- cp $4
- jr z, .asm_52ea
- cp $8
- jr z, .asm_52ea
- cp $c
- jr z, .asm_52ea
+ ld a, [hl] ; facing direction
+ cp SPRITE_FACING_DOWN
+ jr z, .anim
+ cp SPRITE_FACING_UP
+ jr z, .anim
+ cp SPRITE_FACING_LEFT
+ jr z, .anim
+ cp SPRITE_FACING_RIGHT
+ jr z, .anim
ret
-.asm_52ea
+.anim
add b
ld b, a
- ld [$ffe9], a
- call Func_5301
+ ld [hSpriteVRAMSlotAndFacing], a
+ call AdvanceScriptedNPCAnimFrameCounter
ld hl, wSpriteStateData1
ld a, [H_CURRENTSPRITEOFFSET]
add $2
ld l, a
- ld a, [$ffe9]
+ ld a, [hSpriteVRAMSlotAndFacing]
ld b, a
- ld a, [$ffea]
+ ld a, [hSpriteAnimFrameCounter]
add b
ld [hl], a
ret
-Func_5301: ; 5301 (1:5301)
+AdvanceScriptedNPCAnimFrameCounter: ; 5301 (1:5301)
ld a, [H_CURRENTSPRITEOFFSET]
add $7
ld l, a
- ld a, [hl]
+ ld a, [hl] ; intra-animation frame counter
inc a
ld [hl], a
- cp $4
+ cp 4
ret nz
xor a
- ld [hl], a
+ ld [hl], a ; reset intra-animation frame counter
inc l
- ld a, [hl]
+ ld a, [hl] ; animation frame counter
inc a
and $3
ld [hl], a
- ld [$ffea], a
+ ld [hSpriteAnimFrameCounter], a
ret
--- a/engine/overworld/npc_movement.asm
+++ b/engine/overworld/npc_movement.asm
@@ -63,7 +63,7 @@
call FillMemory
ld [hl], $ff
ld a, [wSpriteIndex]
- ld [H_DOWNARROWBLINKCNT2], a
+ ld [H_SPRITEINDEX], a
ld de, wNPCMovementDirections2
call MoveSprite
ld a, $1
--- a/engine/overworld/oam.asm
+++ b/engine/overworld/oam.asm
@@ -4,7 +4,7 @@
ld a, [wUpdateSpritesEnabled]
dec a
- jr z, .asm_4b1e
+ jr z, .updateEnabled
cp 0 - 1
ret nz
@@ -11,18 +11,19 @@
ld [wUpdateSpritesEnabled], a
jp HideSprites
-.asm_4b1e
+.updateEnabled
xor a
- ld [$ff90], a
-.asm_4b21
- ld [$ff8f], a
+ ld [hOAMBufferOffset], a
+.spriteLoop
+ ld [hSpriteDataOffset2], a
+
ld d, wSpriteStateData1 / $100
- ld a, [$ff8f]
+ ld a, [hSpriteDataOffset2]
ld e, a
ld a, [de] ; c1x0
and a
- jp z, .asm_4bad
+ jp z, .nextSprite
inc e
inc e
@@ -31,21 +32,25 @@
cp $ff ; off-screen (don't draw)
jr nz, .visible
- call Func_4bd1
- jr .asm_4bad
+ call GetSpriteScreenXY
+ jr .nextSprite
.visible
- cp $a0
+ cp $a0 ; is the sprite unchanging like an item ball or boulder?
jr c, .usefacing
+
+; unchanging
and $f
- add $10
- jr .asm_4b48
+ add $10 ; skip to the second half of the table which doesn't account for facing direction
+ jr .next
.usefacing
and $f
-.asm_4b48
+
+.next
ld l, a
+; get sprite priority
push de
inc d
ld a, e
@@ -53,15 +58,15 @@
ld e, a
ld a, [de] ; c2x7
and $80
- ld [$ff94], a ; temp store sprite priority
+ ld [hSpritePriority], a ; temp store sprite priority
pop de
+; read the entry from the table
ld h, 0
ld bc, SpriteFacingAndAnimationTable
add hl, hl
add hl, hl
add hl, bc
-
ld a, [hli]
ld c, a
ld a, [hli]
@@ -70,24 +75,25 @@
ld h, [hl]
ld l, a
- call Func_4bd1
+ call GetSpriteScreenXY
- ld a, [$ff90]
+ ld a, [hOAMBufferOffset]
ld e, a
ld d, wOAMBuffer / $100
-.tile
- ld a, [$ff92] ; temp for sprite Y position
+
+.tileLoop
+ ld a, [hSpriteScreenY] ; temp for sprite Y position
add $10 ; Y=16 is top of screen (Y=0 is invisible)
add [hl] ; add Y offset from table
ld [de], a ; write new sprite OAM Y position
inc hl
- ld a, [$ff91] ; temp for sprite X position
+ ld a, [hSpriteScreenX] ; temp for sprite X position
add $8 ; X=8 is left of screen (X=0 is invisible)
add [hl] ; add X offset from table
inc e
ld [de], a ; write new sprite OAM X position
inc e
- ld a, [bc] ; read pattern number offset (accomodates orientation (offset 0,4 or 8) and animation (offset 0 or $80))
+ ld a, [bc] ; read pattern number offset (accommodates orientation (offset 0,4 or 8) and animation (offset 0 or $80))
inc bc
push bc
ld b, a
@@ -99,11 +105,11 @@
; Sprites $a and $b have one face (and therefore 4 tiles instead of 12).
; As a result, sprite $b's tile offset is less than normal.
cp $b
- jr nz, .offset
+ jr nz, .notFourTileSprite
ld a, $a * 12 + 4
- jr .gotoffset
+ jr .next2
-.offset
+.notFourTileSprite
; a *= 12
sla a
sla a
@@ -110,35 +116,36 @@
ld c, a
sla a
add c
-.gotoffset
- add b ; which frame
+
+.next2
+ add b ; add the tile offset from the table (based on frame and facing direction)
pop bc
ld [de], a ; tile id
inc hl
inc e
ld a, [hl]
- bit 1, a ; sprite priority
- jr z, .fg
- ld a, [$ff94] ; facing priority
+ bit 1, a ; is the tile allowed to set the sprite priority bit?
+ jr z, .skipPriority
+ ld a, [hSpritePriority]
or [hl]
-.fg
+.skipPriority
inc hl
ld [de], a
inc e
bit 0, a ; OAMFLAG_ENDOFDATA
- jr z, .tile
+ jr z, .tileLoop
ld a, e
- ld [$ff90], a
+ ld [hOAMBufferOffset], a
-.asm_4bad
- ld a, [$ff8f]
+.nextSprite
+ ld a, [hSpriteDataOffset2]
add $10
cp $100 % $100
- jp nz, .asm_4b21
+ jp nz, .spriteLoop
; Clear unused OAM.
- ld a, [$ff90]
+ ld a, [hOAMBufferOffset]
ld l, a
ld h, wOAMBuffer / $100
ld de, $4
@@ -159,24 +166,24 @@
add hl, de
jr .clear
-Func_4bd1: ; 4bd1 (1:4bd1)
+GetSpriteScreenXY: ; 4bd1 (1:4bd1)
inc e
inc e
ld a, [de] ; c1x4
- ld [$ff92], a
+ ld [hSpriteScreenY], a
inc e
inc e
ld a, [de] ; c1x6
- ld [$ff91], a
- ld a, $4
+ ld [hSpriteScreenX], a
+ ld a, 4
add e
ld e, a
- ld a, [$ff92]
- add $4
+ ld a, [hSpriteScreenY]
+ add 4
and $f0
ld [de], a ; c1xa (y)
inc e
- ld a, [$ff91]
+ ld a, [hSpriteScreenX]
and $f0
ld [de], a ; c1xb (x)
ret
--- a/home.asm
+++ b/home.asm
@@ -3043,8 +3043,8 @@
ret
MoveSprite:: ; 363a (0:363a)
-; move the sprite [$FF8C] with the movement pointed to by de
-; actually only copies the movement data to wcc5b for later
+; move the sprite [H_SPRITEINDEX] with the movement pointed to by de
+; actually only copies the movement data to wNPCMovementDirections for later
call SetSpriteMovementBytesToFF
MoveSprite_:: ; 363d (0:363d)
push hl
@@ -3052,7 +3052,7 @@
call GetSpriteMovementByte1Pointer
xor a
ld [hl],a
- ld hl,wcc5b
+ ld hl,wNPCMovementDirections
ld c,0
.loop
--- a/hram.asm
+++ b/hram.asm
@@ -28,6 +28,17 @@
hHalveItemPrices EQU $FF8E
+hSpriteDataOffset2 EQU $FF8F
+
+hOAMBufferOffset EQU $FF90
+
+hSpriteScreenX EQU $FF91
+hSpriteScreenY EQU $FF92
+
+hTilePlayerStandingOn EQU $FF93
+
+hSpritePriority EQU $FF94
+
; Multiplcation and division variables are meant
; to overlap for back-to-back usage. Big endian.
@@ -154,6 +165,10 @@
hTilesetType EQU $FFD7
H_CURRENTSPRITEOFFSET EQU $FFDA ; multiple of $10
+
+hSpriteVRAMSlotAndFacing EQU $FFE9
+
+hSpriteAnimFrameCounter EQU $FFEA
H_WHOSETURN EQU $FFF3 ; 0 on player’s turn, 1 on enemy’s turn
--- a/main.asm
+++ b/main.asm
@@ -218,9 +218,9 @@
ld a, [H_CURRENTSPRITEOFFSET]
cp b
jr nz, .unequal
- jp Func_5236
+ jp DoScriptedNPCMovement
.unequal
- jp Func_4ed1
+ jp UpdateNPCSprite
; This detects if the current sprite (whose offset is at H_CURRENTSPRITEOFFSET)
; is going to collide with another sprite by looping over the other sprites.
--- a/wram.asm
+++ b/wram.asm
@@ -369,6 +369,8 @@
wAnimationType:: ; cc5b
; values between 0-6. Shake screen horizontally, shake screen vertically, blink Pokemon...
+wNPCMovementDirections:: ; cc5b
+
wcc5b:: ds 1 ; these upcoming values below are miscellaneous storage values
wcc5c:: ds 1 ; used in pokedex evaluation as well
wcc5d:: ds 1 ; used in pokedex evaluation
@@ -1092,7 +1094,10 @@
wcfca:: ds 1 ; also used with audio too
wUpdateSpritesEnabled:: ; cfcb
-; $01 enables UpdateSprites; anything else disables it
+; $00 = causes sprites to be hidden and the value to change to $ff
+; $01 = enabled
+; $ff = disabled
+; other values aren't used
ds 1
W_ENEMYMOVENUM:: ; cfcc
@@ -2291,13 +2296,16 @@
wd72d:: ds 1 ; misc temp flags? (in some scripts, bit 6 and 7 set after a special battle (e.g. gym leaders) has been won)
; also used as a start menu flag
-wd72e:: ds 2 ; more temp misc flags, used with npc movement, main menu and other stuff
+wd72e::
+; bit 7: set if scripted NPC movement has been initialised
+ ds 2 ; more temp misc flags, used with npc movement, main menu and other stuff
+
wd730::
; bit 0: NPC sprite being moved by script
; bit 5: ignore joypad input
; bit 6: print text with no delay between each letter
-; bit 7: set if joypad states are being simulated in the overworld
+; bit 7: set if joypad states are being simulated in the overworld or an NPC's movement is being scripted
ds 1
ds 1
@@ -2328,6 +2336,7 @@
; bit 1: the player is currently stepping down from a door
; bit 2: standing on a warp
; bit 6: jumping down a ledge / fishing animation
+; bit 7: player sprite spinning due to spin tiles (Rocket hidehout / Viridian Gym)
ds 1
wCompletedInGameTradeFlags:: ; d737