Merge pull request #70 from anmart/master

Uncover Sprite system from MapDataPointers

8 files changed, 303 insertions, 170 deletions

diff --git a/src/constants/sprite_constants.asm b/src/constants/sprite_constants.asm
index dc051d9..8447934 100644
--- a/src/constants/sprite_constants.asm
+++ b/src/constants/sprite_constants.asm
@@ -3,20 +3,33 @@ SPRITE_ANIM_BUFFER_CAPACITY EQU 16 ; sprites
 
 ; sprite_anim_struct constants
 	const_def
-	const SPRITE_ANIM_FIELD_00
-	const SPRITE_ANIM_FIELD_01
+	const SPRITE_ANIM_ENABLED
+	const SPRITE_ANIM_ATTRIBUTES
 	const SPRITE_ANIM_COORD_X
 	const SPRITE_ANIM_COORD_Y
 	const SPRITE_ANIM_TILE_ID
-	const SPRITE_ANIM_FIELD_05
-	const SPRITE_ANIM_FIELD_06
-	const SPRITE_ANIM_FIELD_07
-	const SPRITE_ANIM_FIELD_08
-	const SPRITE_ANIM_FIELD_09
-	const SPRITE_ANIM_FIELD_0A
-	const SPRITE_ANIM_FIELD_0B
-	const SPRITE_ANIM_FIELD_0C
-	const SPRITE_ANIM_FIELD_0D
-	const SPRITE_ANIM_MOVEMENT_COUNTER
-	const SPRITE_ANIM_FIELD_0F
+	const SPRITE_ANIM_ID
+	const SPRITE_ANIM_BANK
+	const SPRITE_ANIM_POINTER
+const_value = const_value+1 ; pointer
+	const SPRITE_ANIM_FRAME_OFFSET_POINTER
+const_value = const_value+1 ; pointer
+	const SPRITE_ANIM_FRAME_BANK
+	const SPRITE_ANIM_FRAME_DATA_POINTER
+const_value = const_value+1 ; pointer
+	const SPRITE_ANIM_COUNTER
+	const SPRITE_ANIM_FLAGS
 SPRITE_ANIM_LENGTH EQU const_value
+
+; SPRITE_ANIM_FLAGS values
+	const_def
+	const SPRITE_ANIM_FLAG_X_SUBTRACT
+	const SPRITE_ANIM_FLAG_Y_SUBTRACT
+	const SPRITE_ANIM_FLAG_SPEED
+	const SPRITE_ANIM_FLAG_3
+	const SPRITE_ANIM_FLAG_4
+	const SPRITE_ANIM_FLAG_5
+	const SPRITE_ANIM_FLAG_6
+	const SPRITE_ANIM_FLAG_SKIP_DRAW
+
+SPRITE_FRAME_OFFSET_SIZE EQU 4
diff --git a/src/engine/bank03.asm b/src/engine/bank03.asm
index 1f1e690..4925b76 100644
--- a/src/engine/bank03.asm
+++ b/src/engine/bank03.asm
@@ -681,7 +681,7 @@ Func_c58b: ; c58b (3:458b)
 	call GetPermissionOfMapPosition
 	and $10
 	push af
-	ld c, SPRITE_ANIM_FIELD_0F
+	ld c, SPRITE_ANIM_FLAGS
 	call GetSpriteAnimBufferProperty
 	pop af
 	ld a, [hl]
@@ -747,7 +747,7 @@ UpdatePlayerSprite: ; c5e9 (3:45e9)
 	ld b, a
 	ld a, [wPlayerDirection]
 	add b
-	farcall Func_12ab5
+	farcall StartNewSpriteAnimation
 	pop bc
 	ret
 
@@ -790,10 +790,10 @@ AttemptPlayerMovement: ; c619 (3:4619)
 	ld [wPlayerCurrentlyMoving], a
 	ld a, $10
 	ld [wd338], a
-	ld c, SPRITE_ANIM_FIELD_0F
+	ld c, SPRITE_ANIM_FLAGS
 	call GetSpriteAnimBufferProperty
 	set 2, [hl]
-	ld c, SPRITE_ANIM_MOVEMENT_COUNTER
+	ld c, SPRITE_ANIM_COUNTER
 	call GetSpriteAnimBufferProperty
 	ld a, $4
 	ld [hl], a
@@ -920,10 +920,10 @@ Func_c6dc: ; c6dc (3:46dc)
 Func_c6f7: ; c6f7 (3:46f7)
 	ld a, [wPlayerSpriteIndex]
 	ld [wWhichSprite], a
-	ld c, SPRITE_ANIM_FIELD_0F
+	ld c, SPRITE_ANIM_FLAGS
 	call GetSpriteAnimBufferProperty
 	res 2, [hl]
-	ld c, SPRITE_ANIM_MOVEMENT_COUNTER
+	ld c, SPRITE_ANIM_COUNTER
 	call GetSpriteAnimBufferProperty
 	ld a, $ff
 	ld [hl], a
diff --git a/src/engine/bank04.asm b/src/engine/bank04.asm
index 13df81b..6564bfc 100644
--- a/src/engine/bank04.asm
+++ b/src/engine/bank04.asm
@@ -509,7 +509,7 @@ Func_10fbc: ; 10fbc (4:4fbc)
 	ld b, $37
 .asm_10fd8
 	ld a, b
-	farcall Func_12ab5
+	farcall StartNewSpriteAnimation
 	ret
 
 Func_10fde: ; 10fde (4:4fde)
@@ -529,12 +529,12 @@ Func_10fde: ; 10fde (4:4fde)
 .asm_10ffe
 	ld a, b
 	ld [wd33c], a
-	call Func_12ab5
+	call StartNewSpriteAnimation
 	ld a, $3e
 	farcall GetEventFlagValue
 	or a
 	jr nz, .asm_11015
-	ld c, SPRITE_ANIM_FIELD_0F
+	ld c, SPRITE_ANIM_FLAGS
 	call GetSpriteAnimBufferProperty
 	set 7, [hl]
 .asm_11015
@@ -545,7 +545,7 @@ Func_11016: ; 11016 (4:5016)
 	ld [wWhichSprite], a
 	ld a, [wd33c]
 	inc a
-	call Func_12ab5
+	call StartNewSpriteAnimation
 	ret
 
 Func_11024: ; 11024 (4:5024)
@@ -553,7 +553,7 @@ Func_11024: ; 11024 (4:5024)
 	call PlaySFX
 	ld a, [wPlayerSpriteIndex]
 	ld [wWhichSprite], a
-	ld c, SPRITE_ANIM_FIELD_0F
+	ld c, SPRITE_ANIM_FLAGS
 	call GetSpriteAnimBufferProperty
 	set 2, [hl]
 	ld hl, Unknown_1229f
@@ -1244,7 +1244,7 @@ CreateSpriteAndAnimBufferEntry: ; 1299f (4:699f)
 	push bc
 	push hl
 	call Func_12c05
-	ld [wd5d3], a
+	ld [wCurrSpriteTileID], a
 	xor a
 	ld [wWhichSprite], a
 	call GetFirstSpriteAnimBufferProperty
@@ -1284,13 +1284,13 @@ FillNewSpriteAnimBufferEntry: ; 129d9 (4:69d9)
 	dec c
 	jr nz, .clearSpriteAnimBufferEntryLoop
 	pop hl
-	ld bc, SPRITE_ANIM_FIELD_05 - 1
+	ld bc, SPRITE_ANIM_ID - 1
 	add hl, bc
-	ld a, [wd5d3]
+	ld a, [wCurrSpriteTileID]
 	ld [hli], a
 	ld a, $ff
 	ld [hl], a
-	ld bc, SPRITE_ANIM_MOVEMENT_COUNTER - SPRITE_ANIM_FIELD_05
+	ld bc, SPRITE_ANIM_COUNTER - SPRITE_ANIM_ID
 	add hl, bc
 	ld a, $ff
 	ld [hl], a
@@ -1301,41 +1301,145 @@ FillNewSpriteAnimBufferEntry: ; 129d9 (4:69d9)
 
 	INCROM $129fa, $12a21
 
-Func_12a21: ; 12a21 (4:6a21)
-	INCROM $12a21, $12ab5
+HandleAllSpriteAnimations: ; 12a21 (4:6a21)
+	push af
+	ld a, [wd5d7] ; skip animating this frame if enabled
+	or a
+	jr z, .continue
+	pop af
+	ret
+.continue
+	pop af
+	push af
+	push bc
+	push de
+	push hl
+	call ZeroObjectPositions
+	xor a
+	ld [wWhichSprite], a
+	call GetFirstSpriteAnimBufferProperty
+.spriteLoop
+	ld a, [hl]
+	or a
+	jr z, .nextSprite ; skip if SPRITE_ANIM_ENABLED is 0
+	call TryHandleSpriteAnimationFrame
+	call LoadSpriteDataForAnimationFrame
+.nextSprite
+	ld bc, SPRITE_ANIM_LENGTH
+	add hl, bc
+	ld a, [wWhichSprite]
+	inc a
+	ld [wWhichSprite], a
+	cp SPRITE_ANIM_BUFFER_CAPACITY
+	jr nz, .spriteLoop
+	ld hl, wVBlankOAMCopyToggle
+	inc [hl]
+	pop hl
+	pop de
+	pop bc
+	pop af
+	ret
 
-Func_12ab5: ; 12ab5 (4:6ab5)
+LoadSpriteDataForAnimationFrame: ; 12a5b (4:6a5b)
+	push hl
+	push bc
+	inc hl
+	ld a, [hli]
+	ld [wCurrSpriteAttributes], a
+	ld a, [hli]
+	ld [wCurrSpriteXPos], a
+	ld a, [hli]
+	ld [wCurrSpriteYPos], a
+	ld a, [hl]
+	ld [wCurrSpriteTileID], a
+	ld bc, SPRITE_ANIM_FLAGS - SPRITE_ANIM_TILE_ID
+	add hl, bc
+	ld a, [hl]
+	and 1 << SPRITE_ANIM_FLAG_SKIP_DRAW
+	jr nz, .quit
+	ld bc, SPRITE_ANIM_FRAME_BANK - SPRITE_ANIM_FLAGS
+	add hl, bc
+	ld a, [hli]
+	ld [wd5d6], a
+	or a
+	jr z, .quit
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	call DrawSpriteAnimationFrame
+.quit
+	pop bc
+	pop hl
+	ret
+
+; decrements the given sprite's movement counter (2x if SPRITE_ANIM_FLAG_SPEED is set)
+; moves to the next animation frame if necessary
+TryHandleSpriteAnimationFrame: ; 12a8b (4:6a8b)
+	push hl
+	push bc
+	push de
+	push hl
+	ld d, 1
+	ld bc, SPRITE_ANIM_FLAGS
+	add hl, bc
+	bit SPRITE_ANIM_FLAG_SPEED, [hl]
+	jr z, .skipSpeedIncrease
+	inc d
+.skipSpeedIncrease
+	pop hl
+	ld bc, SPRITE_ANIM_COUNTER
+	add hl, bc
+	ld a, [hl]
+	cp $ff
+	jr z, .exit
+	sub d
+	ld [hl], a
+	jr z, .doNextAnimationFrame
+	jr nc, .exit
+.doNextAnimationFrame
+	ld bc, SPRITE_ANIM_ENABLED - SPRITE_ANIM_COUNTER
+	add hl, bc
+	call HandleAnimationFrame
+.exit
+	pop de
+	pop bc
+	pop hl
+	ret
+
+StartNewSpriteAnimation: ; 12ab5 (4:6ab5)
 	push hl
 	push af
-	ld c, SPRITE_ANIM_FIELD_05
+	ld c, SPRITE_ANIM_ID
 	call GetSpriteAnimBufferProperty
 	pop af
 	cp [hl]
 	pop hl
 	ret z
 	push hl
-	call Func_12ae2
-	call Func_12b13
+	call LoadSpriteAnimPointers
+	call HandleAnimationFrame
 	pop hl
 	ret
 ; 0x12ac9
 
 	INCROM $12ac9, $12ae2
 
-Func_12ae2: ; 12ae2 (4:6ae2)
+; Given an animation ID, fills the current sprite's Animation Pointer and Frame Offset Pointer
+; a - Animation ID for current sprite
+LoadSpriteAnimPointers: ; 12ae2 (4:6ae2)
 	push bc
 	push af
 	call GetFirstSpriteAnimBufferProperty
 	pop af
 	push hl
-	ld bc, $0005
+	ld bc, SPRITE_ANIM_ID
 	add hl, bc
 	ld [hli], a
 	push hl
-	ld l, $6
+	ld l, 6 ; 4th entry in MapDataPointers
 	farcall GetMapDataPointer
-	farcall Func_80229
-	pop hl
+	farcall LoadGraphicsPointerFromHL
+	pop hl ; hl is animation bank
 	ld a, [wTempPointerBank]
 	ld [hli], a
 	ld a, [wTempPointer]
@@ -1354,60 +1458,63 @@ Func_12ae2: ; 12ae2 (4:6ae2)
 	pop bc
 	ret
 
-Func_12b13: ; 12b13 (4:6b13)
+; hl - beginning of current sprite_anim_buffer
+; Handles a full animation frame using all values in animation structure
+; (frame data offset, anim counter, X Mov, Y Mov)
+HandleAnimationFrame: ; 12b13 (4:6b13)
 	push bc
 	push de
 	push hl
-.asm_12b16
+.tryHandlingFrame
 	push hl
-	ld bc, $0006
+	ld bc, SPRITE_ANIM_BANK
 	add hl, bc
 	ld a, [hli]
 	ld [wTempPointerBank], a
 	inc hl
 	inc hl
-	ld a, [hl]
+	ld a, [hl] ; SPRITE_ANIM_FRAME_OFFSET_POINTER
 	ld [wTempPointer], a
-	add $4
+	add SPRITE_FRAME_OFFSET_SIZE ; advance FRAME_OFFSET_POINTER by 1 frame, 4 bytes
 	ld [hli], a
 	ld a, [hl]
 	ld [wTempPointer + 1], a
-	adc $0
+	adc 0
 	ld [hl], a
 	ld de, wd23e
-	ld bc, $0004
+	ld bc, SPRITE_FRAME_OFFSET_SIZE
 	call CopyBankedDataToDE
-	pop hl
+	pop hl ; beginning of current sprite_anim_buffer
 	ld de, wd23e
 	ld a, [de]
-	call Func_12b6a
+	call GetAnimFramePointerFromOffset
 	inc de
 	ld a, [de]
-	call Func_12b89
-	jr c, .asm_12b16
+	call SetAimationCounterAndLoop
+	jr c, .tryHandlingFrame
 	inc de
-	ld bc, $0002
+	ld bc, SPRITE_ANIM_COORD_X
 	add hl, bc
 	push hl
-	ld bc, $000d
+	ld bc, SPRITE_ANIM_FLAGS - SPRITE_ANIM_COORD_X
 	add hl, bc
 	ld b, [hl]
 	pop hl
 	ld a, [de]
-	bit 0, b
-	jr z, .asm_12b5a
+	bit SPRITE_ANIM_FLAG_X_SUBTRACT, b
+	jr z, .addXOffset
 	cpl
 	inc a
-.asm_12b5a
+.addXOffset
 	add [hl]
 	ld [hli], a
 	inc de
 	ld a, [de]
-	bit 1, b
-	jr z, .asm_12b64
+	bit SPRITE_ANIM_FLAG_Y_SUBTRACT, b
+	jr z, .addYOffset
 	cpl
 	inc a
-.asm_12b64
+.addYOffset
 	add [hl]
 	ld [hl], a
 	pop hl
@@ -1415,13 +1522,16 @@ Func_12b13: ; 12b13 (4:6b13)
 	pop bc
 	ret
 
-Func_12b6a: ; 12b6a (4:6b6a)
+; Calls GetAnimationFramePointer after setting up wTempPointerBank and wd4ca
+; a - frame offset from Animation Data
+; hl - beginning of Sprite Anim Buffer
+GetAnimFramePointerFromOffset: ; 12b6a (4:6b6a)
 	ld [wd4ca], a
 	push hl
 	push bc
 	push de
 	push hl
-	ld bc, $0006
+	ld bc, SPRITE_ANIM_BANK
 	add hl, bc
 	ld a, [hli]
 	ld [wTempPointerBank], a
@@ -1430,34 +1540,36 @@ Func_12b6a: ; 12b6a (4:6b6a)
 	ld a, [hli]
 	ld [wTempPointer + 1], a
 	pop hl
-	call Func_3d72
+	call GetAnimationFramePointer ; calls with the original map data script pointer/bank
 	pop de
 	pop bc
 	pop hl
 	ret
 
-Func_12b89: ; 12b89 (4:6b89)
+; Sets the animation counter for the current sprite. If the value is zero, loop the animation
+; a - new animation counter
+SetAimationCounterAndLoop: ; 12b89 (4:6b89)
 	push hl
 	push bc
-	ld bc, $000e
+	ld bc, SPRITE_ANIM_COUNTER
 	add hl, bc
 	ld [hl], a
 	or a
-	jr nz, .asm_12ba4
-	ld bc, $fff9
+	jr nz, .exit
+	ld bc, SPRITE_ANIM_POINTER - SPRITE_ANIM_COUNTER
 	add hl, bc
 	ld a, [hli]
-	add $3
+	add 3 ; skip base bank/pointer at beginning of data structure
 	ld c, a
 	ld a, [hli]
-	adc $0
+	adc 0
 	ld b, a
 	ld a, c
 	ld [hli], a
 	ld a, b
 	ld [hl], a
 	scf
-.asm_12ba4
+.exit
 	pop bc
 	pop hl
 	ret
diff --git a/src/engine/bank07.asm b/src/engine/bank07.asm
index 45cc8b1..9b109be 100644
--- a/src/engine/bank07.asm
+++ b/src/engine/bank07.asm
@@ -319,7 +319,7 @@ Func_1c58e: ; 1c58e (7:458e)
 	add [hl]
 	inc hl
 .asm_1c5ae
-	farcall Func_12ab5
+	farcall StartNewSpriteAnimation
 .quit
 	pop af
 	ld [wWhichSprite], a
@@ -654,7 +654,7 @@ Func_1c94a:
 	call Func_1c980
 	pop af
 	
-	farcall Func_12ab5
+	farcall StartNewSpriteAnimation
 	or a
 	jr .return
 
@@ -667,7 +667,7 @@ Func_1c980: ; 1c980 (7:4980)
 	push hl
 	push bc
 	ld a, [wAnimationQueue]
-	ld c, SPRITE_ANIM_FIELD_01
+	ld c, SPRITE_ANIM_ATTRIBUTES
 	call GetSpriteAnimBufferProperty_SpriteInA
 	call Func_1c9a2
 
diff --git a/src/engine/bank20.asm b/src/engine/bank20.asm
index b656f90..867ee77 100644
--- a/src/engine/bank20.asm
+++ b/src/engine/bank20.asm
@@ -276,6 +276,8 @@ Func_801f1: ; 801f1 (20:41f1)
 	pop hl
 	ret
 
+; l - map data offset (0,2,4,6,8 for banks 0,1,2,3,4)
+; a - map index (inside of the given bank)
 GetMapDataPointer: ; 8020f (20:420f)
 	push bc
 	push af
@@ -296,13 +298,14 @@ GetMapDataPointer: ; 8020f (20:420f)
 	pop bc
 	ret
 
-Func_80229: ; 80229 (20:4229)
+; Loads a pointer from [hl] to wTempPointer. Adds the graphics bank offset ($20)
+LoadGraphicsPointerFromHL: ; 80229 (20:4229)
 	ld a, [hli]
 	ld [wTempPointer], a
 	ld a, [hli]
 	ld [wTempPointer + 1], a
 	ld a, [hli]
-	add $20
+	add BANK(MapDataPointers)
 	ld [wTempPointerBank], a
 	ret
 ; 0x80238
@@ -313,7 +316,7 @@ Func_8025b: ; 8025b (20:425b)
 	push hl
 	ld l, $4
 	call GetMapDataPointer
-	call Func_80229
+	call LoadGraphicsPointerFromHL
 	ld a, [hl]
 	push af
 	ld [wd4c8], a
@@ -390,7 +393,7 @@ Func_803b9: ; 803b9 (20:43b9)
 	ld l, $00
 	ld a, [wd131]
 	call GetMapDataPointer
-	call Func_80229
+	call LoadGraphicsPointerFromHL
 	ld a, [hl]
 	ld [$d239], a
 	ret
@@ -515,15 +518,19 @@ Func_80baa: ; 80baa (20:4baa)
 
 	INCROM $80c21, $80e5a
 
-Unknown_80e5a: ; 80e5a (20:4e5a)
-	INCROM $80e5a, $80e5d
+SpriteNullAnimationPointer: ; 80e5a (20:4e5a)
+	dw SpriteNullAnimationFrame
+
+SpriteNullAnimationFrame:
+	db 0
 
 ; might be closer to "screen specific data" than map data
+; data in each section is 4 bytes long.
 MapDataPointers: ; 80e5d (20:4e5d)
 	dw MapDataPointers_80e67
 	dw MapDataPointers_8100f
 	dw MapDataPointers_8116b
-	dw MapDataPointers_81333
+	dw SpriteAnimationPointers
 	dw MapDataPointers_81697
 
 MapDataPointers_80e67: ; 80e67 (20:4e67)
@@ -535,7 +542,8 @@ MapDataPointers_8100f: ; 8100f (20:500f)
 MapDataPointers_8116b: ; 8116b (20:516b)
 	INCROM $8116b, $81333
 
-MapDataPointers_81333: ; 81333 (20:5333)
+; pointer low, pointer high, bank (minus $20), unknown
+SpriteAnimationPointers: ; 81333 (20:5333)
 	INCROM $81333, $81697
 
 MapDataPointers_81697: ; 81697 (20:5697)
diff --git a/src/engine/home.asm b/src/engine/home.asm
index 78e0bf1..03e8ca4 100644
--- a/src/engine/home.asm
+++ b/src/engine/home.asm
@@ -11522,141 +11522,145 @@ Func_3ca4: ; 3ca4 (0:3ca4)
 Func_3cb4: ; 3cb4 (0:3cb4)
 	ldh a, [hBankROM]
 	push af
-	ld a, BANK(Func_12a21)
+	ld a, BANK(HandleAllSpriteAnimations)
 	call BankswitchROM
-	call Func_12a21
+	call HandleAllSpriteAnimations
 	pop af
 	call BankswitchROM
 	ret
 ; 0x3cc4
 
-; refresh sprites?
-Func_3cc4: ; 3cc4 (0:3cc4)
+; hl - pointer to animation frame
+; wd5d6 - bank of animation frame
+DrawSpriteAnimationFrame: ; 3cc4 (0:3cc4)
 	ldh a, [hBankROM]
 	push af
 	ld a, [wd5d6]
 	call BankswitchROM
-	ld a, [wd5d1]
+	ld a, [wCurrSpriteXPos]
 	cp $f0
-	ld a, $00
-	jr c, .asm_3cd7
+	ld a, 0
+	jr c, .notNearRight
 	dec a
-.asm_3cd7
-	ld [wd5d4], a
-	ld a, [wd5d2]
+.notNearRight
+	ld [wCurrSpriteRightEdgeCheck], a
+	ld a, [wCurrSpriteYPos]
 	cp $f0
-	ld a, $00
-	jr c, .asm_3ce4
+	ld a, 0
+	jr c, .setBottomEdgeCheck
 	dec a
-.asm_3ce4
-	ld [wd5d5], a
+.setBottomEdgeCheck
+	ld [wCurrSpriteBottomEdgeCheck], a
 	ld a, [hli]
 	or a
 	jp z, .done
 	ld c, a
-.asm_3ced
+.loop
 	push bc
 	push hl
-	ld b, $00
+	ld b, 0
 	bit 7, [hl]
-	jr z, .asm_3cf6
+	jr z, .beginY
 	dec b
-.asm_3cf6
-	ld a, [wd5d0]
-	bit 6, a
-	jr z, .asm_3d10
+.beginY
+	ld a, [wCurrSpriteAttributes]
+	bit OAM_Y_FLIP, a
+	jr z, .unflippedY
 	ld a, [hl]
-	add $08
+	add 8 ; size of a tile
 	ld c, a
-	ld a, $00
+	ld a, 0
 	adc b
 	ld b, a
-	ld a, [wd5d2]
+	ld a, [wCurrSpriteYPos]
 	sub c
 	ld e, a
-	ld a, [wd5d5]
+	ld a, [wCurrSpriteBottomEdgeCheck]
 	sbc b
-	jr .asm_3d19
-.asm_3d10
-	ld a, [wd5d2]
+	jr .finishYPosition
+.unflippedY
+	ld a, [wCurrSpriteYPos]
 	add [hl]
 	ld e, a
-	ld a, [wd5d5]
+	ld a, [wCurrSpriteBottomEdgeCheck]
 	adc b
-.asm_3d19
+.finishYPosition
 	or a
-	jr nz, .asm_3d64
+	jr nz, .endCurrentIteration
 	inc hl
-	ld b, $00
+	ld b, 0
 	bit 7, [hl]
-	jr z, .asm_3d24
+	jr z, .beginX
 	dec b
-.asm_3d24
-	ld a, [wd5d0]
-	bit 5, a
-	jr z, .asm_3d3e
+.beginX
+	ld a, [wCurrSpriteAttributes]
+	bit OAM_X_FLIP, a
+	jr z, .unflippedX
 	ld a, [hl]
-	add $08
+	add 8 ; size of a tile
 	ld c, a
-	ld a, $00
+	ld a, 0
 	adc b
 	ld b, a
-	ld a, [wd5d1]
+	ld a, [wCurrSpriteXPos]
 	sub c
 	ld d, a
-	ld a, [wd5d4]
+	ld a, [wCurrSpriteRightEdgeCheck]
 	sbc b
-	jr .asm_3d47
-.asm_3d3e
-	ld a, [wd5d1]
+	jr .finishXPosition
+.unflippedX
+	ld a, [wCurrSpriteXPos]
 	add [hl]
 	ld d, a
-	ld a, [wd5d4]
+	ld a, [wCurrSpriteRightEdgeCheck]
 	adc b
-.asm_3d47
+.finishXPosition
 	or a
-	jr nz, .asm_3d64
+	jr nz, .endCurrentIteration
 	inc hl
-	ld a, [wd5d3]
+	ld a, [wCurrSpriteTileID]
 	add [hl]
 	ld c, a
 	inc hl
-	ld a, [wd5d0]
+	ld a, [wCurrSpriteAttributes]
 	add [hl]
-	and $17
+	and OAM_PALETTE | (1 << OAM_OBP_NUM)
 	ld b, a
-	ld a, [wd5d0]
+	ld a, [wCurrSpriteAttributes]
 	xor [hl]
-	and $e0
+	and (1 << OAM_X_FLIP) | (1 << OAM_Y_FLIP) | (1 << OAM_PRIORITY)
 	or b
 	ld b, a
 	inc hl
 	call SetOneObjectAttributes
-.asm_3d64
+.endCurrentIteration
 	pop hl
-	ld bc, $4
+	ld bc, 4 ; size of info for one sub tile
 	add hl, bc
 	pop bc
 	dec c
-	jr nz, .asm_3ced
+	jr nz, .loop
 .done
 	pop af
 	call BankswitchROM
 	ret
-; 0x3d72
 
-Func_3d72: ; 3d72 (0:3d72)
+; Loads a pointer to the current animation frame into SPRITE_ANIM_FRAME_DATA_POINTER using 
+; the current frame's offset
+; [wd4ca] - current frame offset
+; wTempPointer* - Pointer to current Animation
+GetAnimationFramePointer: ; 3d72 (0:3d72)
 	ldh a, [hBankROM]
 	push af
 	push hl
 	push hl
 	ld a, [wd4ca]
 	cp $ff
-	jr nz, .asm_3d84
-	ld de, Unknown_80e5a
+	jr nz, .useLoadedOffset
+	ld de, SpriteNullAnimationPointer
 	xor a
-	jr .asm_3da1
-.asm_3d84
+	jr .loadPointer
+.useLoadedOffset
 	ld a, [wTempPointer]
 	ld l, a
 	ld a, [wTempPointer + 1]
@@ -11672,13 +11676,13 @@ Func_3d72: ; 3d72 (0:3d72)
 	ld e, a
 	inc hl
 	ld a, [hl]
-	adc $0
+	adc 0
 	ld d, a
 	pop af
-.asm_3da1
-	add BANK(Unknown_80e5a)
+.loadPointer
+	add BANK(SpriteNullAnimationPointer)
 	pop hl
-	ld bc, $000b
+	ld bc, SPRITE_ANIM_FRAME_BANK
 	add hl, bc
 	ld [hli], a
 	call BankswitchROM
@@ -11694,7 +11698,7 @@ Func_3d72: ; 3d72 (0:3d72)
 
 GetFirstSpriteAnimBufferProperty: ; 3db7 (0:3db7)
 	push bc
-	ld c, SPRITE_ANIM_FIELD_00
+	ld c, SPRITE_ANIM_ENABLED
 	call GetSpriteAnimBufferProperty
 	pop bc
 	ret
@@ -11729,7 +11733,7 @@ GetSpriteAnimBufferProperty_SpriteInA:
 Func_3ddb: ; 3ddb (0:3ddb)
 	push hl
 	push bc
-	ld c, SPRITE_ANIM_FIELD_0F
+	ld c, SPRITE_ANIM_FLAGS
 	call GetSpriteAnimBufferProperty_SpriteInA
 	res 2, [hl]
 	pop bc
@@ -11740,7 +11744,7 @@ Func_3ddb: ; 3ddb (0:3ddb)
 Func_3de7: ; 3de7 (0:3de7)
 	push hl
 	push bc
-	ld c, SPRITE_ANIM_FIELD_0F
+	ld c, SPRITE_ANIM_FLAGS
 	call GetSpriteAnimBufferProperty_SpriteInA
 	set 2, [hl]
 	pop bc
diff --git a/src/macros/wram.asm b/src/macros/wram.asm
index c8b9a88..8545972 100644
--- a/src/macros/wram.asm
+++ b/src/macros/wram.asm
@@ -46,24 +46,20 @@ text_header: MACRO
 \1RomBank::     ds 1
 ENDM
 
-; TODO: Figure out what the rest are for
 sprite_anim_struct: MACRO
-\1Field0x00::  ds 1
-\1Field0x01::  ds 1 ; movement handling / palette
-\1CoordX::     ds 1
-\1CoordY::     ds 1
-\1TileID::     ds 1
-\1Field0x05::  ds 1
-\1Field0x06::  ds 1
-\1Field0x07::  ds 1
-\1Field0x08::  ds 1
-\1Field0x09::  ds 1
-\1Field0x0a::  ds 1
-\1Field0x0b::  ds 1
-\1Field0x0c::  ds 1
-\1Field0x0d::  ds 1
-\1MovementCounter::  ds 1
-\1Field0x0f::  ds 1
+\1Enabled::             ds 1
+\1Attributes::          ds 1
+\1CoordX::              ds 1
+\1CoordY::              ds 1
+\1TileID::              ds 1
+\1ID::                  ds 1
+\1Bank::                ds 1
+\1Pointer::             ds 2
+\1FrameOffsetPointer::  ds 2
+\1FrameBank::           ds 1
+\1FrameDataPointer::    ds 2
+\1Counter::             ds 1
+\1Flags::               ds 1
 ENDM
 
 loaded_npc_struct: MACRO
diff --git a/src/wram.asm b/src/wram.asm
index a54a8d2..15a6e1a 100644
--- a/src/wram.asm
+++ b/src/wram.asm
@@ -2390,22 +2390,22 @@ wSpriteAnimBuffer:: ; d4d0
 	sprite_anim_struct wSprite15
 	sprite_anim_struct wSprite16
 
-wd5d0:: ; d5d0
+wCurrSpriteAttributes:: ; d5d0
 	ds $1
 
-wd5d1:: ; d5d1
+wCurrSpriteXPos:: ; d5d1
 	ds $1
 
-wd5d2:: ; d5d2
+wCurrSpriteYPos:: ; d5d2
 	ds $1
 
-wd5d3:: ; d5d3
+wCurrSpriteTileID:: ; d5d3
 	ds $1
 
-wd5d4:: ; d5d4
+wCurrSpriteRightEdgeCheck:: ; d5d4
 	ds $1
 
-wd5d5:: ; d5d5
+wCurrSpriteBottomEdgeCheck:: ; d5d5
 	ds $1
 
 wd5d6:: ; d5d6