Avoid magic numbers for most `CopyData` calls (#542)

22 files changed, 68 insertions, 57 deletions

diff --git a/constants/gfx_constants.asm b/constants/gfx_constants.asm
index 1a06238c..c3f29ca5 100644
--- a/constants/gfx_constants.asm
+++ b/constants/gfx_constants.asm
@@ -7,7 +7,11 @@ DEF SCREEN_BLOCK_HEIGHT EQU 5 ; blocks
 DEF SURROUNDING_WIDTH  EQU SCREEN_BLOCK_WIDTH * BLOCK_WIDTH ; tiles
 DEF SURROUNDING_HEIGHT EQU SCREEN_BLOCK_HEIGHT * BLOCK_HEIGHT ; tiles
 
-DEF SPRITEBUFFERSIZE EQU 7 * 7 * TILE_1BPP_SIZE
+DEF PIC_WIDTH  EQU 7 ; tiles
+DEF PIC_HEIGHT EQU PIC_WIDTH ; tiles
+DEF PIC_SIZE   EQU PIC_WIDTH * PIC_HEIGHT ; tiles
+
+DEF SPRITEBUFFERSIZE EQU PIC_WIDTH * PIC_HEIGHT * TILE_1BPP_SIZE
 
 ; HP bar
 DEF HP_BAR_GREEN  EQU 0
diff --git a/constants/text_constants.asm b/constants/text_constants.asm
index 4dbdf666..ed195172 100644
--- a/constants/text_constants.asm
+++ b/constants/text_constants.asm
@@ -1,6 +1,7 @@
 DEF NAME_LENGTH        EQU 11
 DEF ITEM_NAME_LENGTH   EQU 13
 DEF NAME_BUFFER_LENGTH EQU 20
+DEF GYM_CITY_LENGTH    EQU 17
 
 ; PrintNumber, PrintBCDNumber
 	const_def 5
diff --git a/engine/battle/animations.asm b/engine/battle/animations.asm
index 711ebda4..f66be640 100644
--- a/engine/battle/animations.asm
+++ b/engine/battle/animations.asm
@@ -1213,12 +1213,12 @@ _AnimationSlideMonUp:
 	push bc
 
 ; In each iteration, slide up all rows but the top one (which is overwritten).
-	ld b, 6
+	ld b, PIC_HEIGHT - 1
 .slideLoop
 	push bc
 	push de
 	push hl
-	ld bc, 7
+	ld bc, PIC_WIDTH
 	call CopyData
 ; Note that de and hl are popped in the same order they are pushed, swapping
 ; their values. When CopyData is called, hl points to a tile 1 row below
@@ -1242,10 +1242,10 @@ _AnimationSlideMonUp:
 	ld a, [wSlideMonUpBottomRowLeftTile]
 	inc a
 	ld [wSlideMonUpBottomRowLeftTile], a
-	ld c, 7
+	ld c, PIC_WIDTH
 .fillBottomRowLoop
 	ld [hli], a
-	add 7
+	add PIC_WIDTH
 	dec c
 	jr nz, .fillBottomRowLoop
 
@@ -1723,10 +1723,10 @@ AnimationMinimizeMon:
 	ld hl, wTempPic
 	push hl
 	xor a
-	ld bc, (7 * 7) tiles
+	ld bc, PIC_SIZE tiles
 	call FillMemory
 	pop hl
-	ld de, (7 * 3 + 4) tiles + TILE_SIZE / 4
+	ld de, (PIC_WIDTH * 3 + 4) tiles + TILE_SIZE / 4
 	add hl, de
 	ld de, MinimizedMonSprite
 	ld c, MinimizedMonSpriteEnd - MinimizedMonSprite
@@ -1774,7 +1774,7 @@ AnimationSlideMonDownAndHide:
 	jr nz, .loop
 	call AnimationHideMonPic
 	ld hl, wTempPic
-	ld bc, 7 * 7 tiles
+	ld bc, PIC_SIZE tiles
 	xor a
 	call FillMemory
 	jp CopyTempPicToMonPic
@@ -1867,7 +1867,7 @@ CopyTempPicToMonPic:
 	ld hl, vFrontPic ; enemy turn
 .next
 	ld de, wTempPic
-	ld bc, 7 * 7
+	ld bc, PIC_SIZE
 	jp CopyVideoData
 
 AnimationWavyScreen:
@@ -1935,7 +1935,7 @@ AnimationSubstitute:
 ; Changes the pokemon's sprite to the mini sprite
 	ld hl, wTempPic
 	xor a
-	ld bc, 7 * 7 tiles
+	ld bc, PIC_SIZE tiles
 	call FillMemory
 	ldh a, [hWhoseTurn]
 	and a
@@ -2473,7 +2473,7 @@ AnimationShakeEnemyHUD:
 ; Make a copy of the back pic's tile patterns in sprite tile pattern VRAM.
 	ld de, vBackPic
 	ld hl, vSprites
-	ld bc, 7 * 7
+	ld bc, PIC_SIZE
 	call CopyVideoData
 
 	xor a
diff --git a/engine/battle/core.asm b/engine/battle/core.asm
index 672bd416..4c25373a 100644
--- a/engine/battle/core.asm
+++ b/engine/battle/core.asm
@@ -1183,17 +1183,17 @@ SlideDownFaintedMonPic:
 	push af
 	set BIT_NO_TEXT_DELAY, a
 	ld [wStatusFlags5], a
-	ld b, 7 ; number of times to slide
+	ld b, PIC_HEIGHT ; number of times to slide
 .slideStepLoop ; each iteration, the mon is slid down one row
 	push bc
 	push de
 	push hl
-	ld b, 6 ; number of rows
+	ld b, PIC_HEIGHT - 1 ; number of rows
 .rowLoop
 	push bc
 	push hl
 	push de
-	ld bc, $7
+	ld bc, PIC_WIDTH
 	call CopyData
 	pop de
 	pop hl
@@ -1225,7 +1225,8 @@ SlideDownFaintedMonPic:
 	ret
 
 SevenSpacesText:
-	db "       @"
+	ds PIC_WIDTH, ' '
+	db "@"
 
 ; slides the player or enemy trainer off screen
 ; a is the number of tiles to slide it horizontally (always 9 for the player trainer or 8 for the enemy trainer)
@@ -1237,7 +1238,7 @@ SlideTrainerPicOffScreen:
 .slideStepLoop ; each iteration, the trainer pic is slid one tile left/right
 	push bc
 	push hl
-	ld b, 7 ; number of rows
+	ld b, PIC_HEIGHT ; number of rows
 .rowLoop
 	push hl
 	ldh a, [hSlideAmount]
@@ -1794,7 +1795,7 @@ AnimateRetreatingPlayerMon:
 	lb bc, 7, 7
 	jp ClearScreenArea
 
-; Copies player's current pokemon's current HP and status into the party
+; Copies player's current pokemon's current HP, party pos, and status into the party
 ; struct data so it stays after battle or switching
 ReadPlayerMonCurHPAndStatus:
 	ld a, [wPlayerMonNumber]
@@ -1804,7 +1805,7 @@ ReadPlayerMonCurHPAndStatus:
 	ld d, h
 	ld e, l
 	ld hl, wBattleMonHP
-	ld bc, $4               ; 2 bytes HP, 1 byte unknown (unused?), 1 byte status
+	ld bc, MON_STATUS + 1 - MON_HP ; also copies party pos in-between HP and status
 	jp CopyData
 
 DrawHUDsAndHPBars:
@@ -6352,7 +6353,7 @@ LoadPlayerBackPic:
 	ld [hl], d ; OAM Y
 	inc hl
 	ld [hl], e ; OAM X
-	ld a, $8 ; height of tile
+	ld a, TILE_HEIGHT
 	add d ; increase Y by height of tile
 	ld d, a
 	inc hl
@@ -6366,7 +6367,7 @@ LoadPlayerBackPic:
 	ldh a, [hOAMTile]
 	add $4 ; increase tile number by 4
 	ldh [hOAMTile], a
-	ld a, $8 ; width of tile
+	ld a, TILE_WIDTH
 	add e ; increase X by width of tile
 	ld e, a
 	dec b
@@ -6381,7 +6382,7 @@ LoadPlayerBackPic:
 	ld de, sSpriteBuffer1
 	ldh a, [hLoadedROMBank]
 	ld b, a
-	ld c, 7 * 7
+	ld c, PIC_SIZE
 	call CopyVideoData
 	xor a
 	ld [rRAMG], a
diff --git a/engine/battle/draw_hud_pokeball_gfx.asm b/engine/battle/draw_hud_pokeball_gfx.asm
index 983e7cdf..011b4b33 100644
--- a/engine/battle/draw_hud_pokeball_gfx.asm
+++ b/engine/battle/draw_hud_pokeball_gfx.asm
@@ -119,7 +119,7 @@ WritePokeballOAMData:
 PlacePlayerHUDTiles:
 	ld hl, PlayerBattleHUDGraphicsTiles
 	ld de, wHUDGraphicsTiles
-	ld bc, $3
+	ld bc, wHUDGraphicsTilesEnd - wHUDGraphicsTiles
 	call CopyData
 	hlcoord 18, 10
 	ld de, -1
@@ -134,7 +134,7 @@ PlayerBattleHUDGraphicsTiles:
 PlaceEnemyHUDTiles:
 	ld hl, EnemyBattleHUDGraphicsTiles
 	ld de, wHUDGraphicsTiles
-	ld bc, $3
+	ld bc, wHUDGraphicsTilesEnd - wHUDGraphicsTiles
 	call CopyData
 	hlcoord 1, 2
 	ld de, $1
@@ -150,7 +150,7 @@ PlaceHUDTiles:
 	ld [hl], $73
 	ld bc, SCREEN_WIDTH
 	add hl, bc
-	ld a, [wHUDGraphicsTiles + 1] ; leftmost tile
+	ld a, [wHUDCornerTile] ; leftmost tile
 	ld [hl], a
 	ld a, 8
 .loop
@@ -159,7 +159,7 @@ PlaceHUDTiles:
 	dec a
 	jr nz, .loop
 	add hl, de
-	ld a, [wHUDGraphicsTiles + 2] ; rightmost tile
+	ld a, [wHUDTriangleTile] ; rightmost tile
 	ld [hl], a
 	ret
 
diff --git a/engine/battle/effects.asm b/engine/battle/effects.asm
index e107853c..003592aa 100644
--- a/engine/battle/effects.asm
+++ b/engine/battle/effects.asm
@@ -754,7 +754,7 @@ PrintStatText:
 	jr .findStatName_inner
 .foundStatName
 	ld de, wStringBuffer
-	ld bc, $a
+	ld bc, NAME_LENGTH - 1 ; all StatModTextStrings are at most 10 bytes
 	jp CopyData
 
 INCLUDE "data/battle/stat_mod_names.asm"
diff --git a/engine/battle/ghost_marowak_anim.asm b/engine/battle/ghost_marowak_anim.asm
index 4b1eb452..1040f85f 100644
--- a/engine/battle/ghost_marowak_anim.asm
+++ b/engine/battle/ghost_marowak_anim.asm
@@ -52,7 +52,7 @@ MarowakAnim:
 CopyMonPicFromBGToSpriteVRAM:
 	ld de, vFrontPic
 	ld hl, vSprites
-	ld bc, 7 * 7
+	ld bc, PIC_SIZE
 	call CopyVideoData
 	ld a, $10
 	ld [wBaseCoordY], a
diff --git a/engine/battle/move_effects/transform.asm b/engine/battle/move_effects/transform.asm
index 6f2e705c..343fa3ca 100644
--- a/engine/battle/move_effects/transform.asm
+++ b/engine/battle/move_effects/transform.asm
@@ -82,14 +82,15 @@ TransformEffect_:
 	ld a, [hli]
 	ld [de], a
 	inc de
-; Attack, Defense, Speed, and Special stats
+; Skip level and max HP
 	inc hl
 	inc hl
 	inc hl
 	inc de
 	inc de
 	inc de
-	ld bc, $8
+; Attack, Defense, Speed, and Special stats
+	ld bc, (NUM_STATS - 1) * 2
 	call CopyData
 	ld bc, wBattleMonMoves - wBattleMonPP
 	add hl, bc ; ld hl, wBattleMonMoves
@@ -99,7 +100,7 @@ TransformEffect_:
 	ld a, [hli]
 	and a
 	jr z, .lessThanFourMoves
-	ld a, $5
+	ld a, 5
 	ld [de], a
 	inc de
 	dec b
@@ -136,7 +137,7 @@ TransformEffect_:
 	ld l, e
 	pop de
 .gotStatsOrModsToCopy
-	ld bc, $8
+	ld bc, (NUM_STATS - 1) * 2
 	jp CopyData
 
 .failed
diff --git a/engine/battle/trainer_ai.asm b/engine/battle/trainer_ai.asm
index 4134047f..546dd60e 100644
--- a/engine/battle/trainer_ai.asm
+++ b/engine/battle/trainer_ai.asm
@@ -583,7 +583,7 @@ AISwitchIfEnoughMons:
 
 SwitchEnemyMon:
 
-; prepare to withdraw the active monster: copy hp, number, and status to roster
+; prepare to withdraw the active monster: copy HP, party pos, and status to roster
 
 	ld a, [wEnemyMonPartyPos]
 	ld hl, wEnemyMon1HP
@@ -592,7 +592,7 @@ SwitchEnemyMon:
 	ld d, h
 	ld e, l
 	ld hl, wEnemyMonHP
-	ld bc, 4
+	ld bc, MON_STATUS + 1 - MON_HP ; also copies party pos in-between HP and status
 	call CopyData
 
 	ld hl, AIBattleWithdrawText
diff --git a/engine/events/in_game_trades.asm b/engine/events/in_game_trades.asm
index 4c6041b0..5cc251f4 100644
--- a/engine/events/in_game_trades.asm
+++ b/engine/events/in_game_trades.asm
@@ -226,7 +226,7 @@ InGameTrade_CopyDataToReceivedMon:
 	ld bc, wPartyMon2 - wPartyMon1
 	call InGameTrade_GetReceivedMonPointer
 	ld hl, wTradedEnemyMonOTID
-	ld bc, $2
+	ld bc, 2
 	jp CopyData
 
 ; the received mon's index is (partyCount - 1),
diff --git a/engine/items/item_effects.asm b/engine/items/item_effects.asm
index 1b68e47a..7fffae59 100644
--- a/engine/items/item_effects.asm
+++ b/engine/items/item_effects.asm
@@ -1302,13 +1302,13 @@ ItemUseMedicine:
 .statNameInnerLoop
 	ld a, [hli]
 	ld b, a
-	ld a, $50
+	ld a, '@'
 	cp b
 	jr nz, .statNameInnerLoop
 	jr .statNameLoop
 .gotStatName
 	ld de, wStringBuffer
-	ld bc, 10
+	ld bc, NAME_LENGTH - 1 ; all VitaminStats are at most 10 bytes
 	call CopyData ; copy the stat's name to wStringBuffer
 	ld a, SFX_HEAL_AILMENT
 	call PlaySound
@@ -2029,7 +2029,7 @@ ItemUsePPRestore:
 	ld bc, wPartyMon2 - wPartyMon1
 	call AddNTimes
 	ld de, wBattleMonPP
-	ld bc, 4
+	ld bc, NUM_MOVES
 	call CopyData ; copy party data to in-battle data
 .skipUpdatingInBattleData
 	ld a, SFX_HEAL_AILMENT
diff --git a/engine/items/town_map.asm b/engine/items/town_map.asm
index 573ba581..35acaa29 100644
--- a/engine/items/town_map.asm
+++ b/engine/items/town_map.asm
@@ -20,7 +20,7 @@ DisplayTownMap:
 	call PlaceString
 	ld hl, wShadowOAMSprite00
 	ld de, wShadowOAMBackupSprite00
-	ld bc, 4 * 4
+	ld bc, OBJ_SIZE * 4
 	call CopyData
 	ld hl, vSprites tile BIRD_BASE_TILE
 	ld de, TownMapCursor
@@ -64,7 +64,7 @@ DisplayTownMap:
 	call PlaceString
 	ld hl, wShadowOAMSprite04
 	ld de, wShadowOAMBackupSprite04
-	ld bc, 4 * 4
+	ld bc, OBJ_SIZE * 4
 	call CopyData
 .inputLoop
 	call TownMapSpriteBlinkingAnimation
diff --git a/engine/movie/evolution.asm b/engine/movie/evolution.asm
index 4258b94d..b6e541c5 100644
--- a/engine/movie/evolution.asm
+++ b/engine/movie/evolution.asm
@@ -30,7 +30,7 @@ EvolveMon:
 	call Evolution_LoadPic
 	ld de, vFrontPic
 	ld hl, vBackPic
-	ld bc, 7 * 7
+	ld bc, PIC_SIZE
 	call CopyVideoData
 	ld a, [wEvoOldSpecies]
 	ld [wCurPartySpecies], a
diff --git a/engine/movie/hall_of_fame.asm b/engine/movie/hall_of_fame.asm
index b2c0de42..88e777af 100644
--- a/engine/movie/hall_of_fame.asm
+++ b/engine/movie/hall_of_fame.asm
@@ -188,7 +188,7 @@ HoFLoadPlayerPics:
 	call UncompressSpriteFromDE
 	ld hl, sSpriteBuffer1
 	ld de, sSpriteBuffer0
-	ld bc, $310
+	ld bc, 2 * SPRITEBUFFERSIZE
 	call CopyData
 	ld de, vFrontPic
 	call InterlaceMergeSpriteBuffers
diff --git a/engine/movie/splash.asm b/engine/movie/splash.asm
index 7f06c68b..cc5526ae 100644
--- a/engine/movie/splash.asm
+++ b/engine/movie/splash.asm
@@ -133,7 +133,7 @@ AnimateShootingStar:
 ; shift the existing OAM entries down to make room for the next wave
 	ld hl, wShadowOAMSprite04
 	ld de, wShadowOAM
-	ld bc, $50
+	ld bc, OBJ_SIZE * 20
 	call CopyData
 
 	pop af
diff --git a/engine/overworld/cut2.asm b/engine/overworld/cut2.asm
index 69c8cb13..7697d430 100644
--- a/engine/overworld/cut2.asm
+++ b/engine/overworld/cut2.asm
@@ -77,13 +77,13 @@ AnimCutGrass_UpdateOAMEntries:
 AnimCutGrass_SwapOAMEntries:
 	ld hl, wShadowOAMSprite36
 	ld de, wBuffer
-	ld bc, $8
+	ld bc, 2 * OBJ_SIZE
 	call CopyData
 	ld hl, wShadowOAMSprite38
 	ld de, wShadowOAMSprite36
-	ld bc, $8
+	ld bc, 2 * OBJ_SIZE
 	call CopyData
 	ld hl, wBuffer
 	ld de, wShadowOAMSprite38
-	ld bc, $8
+	ld bc, 2 * OBJ_SIZE
 	jp CopyData
diff --git a/engine/overworld/player_animations.asm b/engine/overworld/player_animations.asm
index 4ed1f49f..657c001e 100644
--- a/engine/overworld/player_animations.asm
+++ b/engine/overworld/player_animations.asm
@@ -264,7 +264,7 @@ InitFacingDirectionList:
 	ld [wSavedPlayerScreenY], a
 	ld hl, PlayerSpinningFacingOrder
 	ld de, wFacingDirectionList
-	ld bc, 4
+	ld bc, OBJ_SIZE
 	call CopyData
 	ld a, [wSpritePlayerStateData1ImageIndex] ; (image index is locked to standing images)
 	ld hl, wFacingDirectionList
@@ -288,7 +288,7 @@ SpinPlayerSprite:
 	push hl
 	ld hl, wFacingDirectionList
 	ld de, wFacingDirectionList - 1
-	ld bc, 4
+	ld bc, OBJ_SIZE
 	call CopyData
 	ld a, [wFacingDirectionList - 1]
 	ld [wFacingDirectionList + 3], a
@@ -393,7 +393,7 @@ FishingAnim:
 	ld hl, FishingRodOAM
 	add hl, bc
 	ld de, wShadowOAMSprite39
-	ld bc, $4
+	ld bc, OBJ_SIZE
 	call CopyData
 	ld c, 100
 	call DelayFrames
diff --git a/engine/pokemon/add_mon.asm b/engine/pokemon/add_mon.asm
index 7eaca222..a7c201ea 100644
--- a/engine/pokemon/add_mon.asm
+++ b/engine/pokemon/add_mon.asm
@@ -231,7 +231,7 @@ _AddPartyMon::
 	dec a
 	jr nz, .calcFreshStats
 	ld hl, wEnemyMonMaxHP
-	ld bc, $a
+	ld bc, NUM_STATS * 2
 	call CopyData          ; copy stats of cur enemy mon
 	pop hl
 	jr .done
diff --git a/engine/slots/slot_machine.asm b/engine/slots/slot_machine.asm
index 147519c7..2e02caf3 100644
--- a/engine/slots/slot_machine.asm
+++ b/engine/slots/slot_machine.asm
@@ -447,7 +447,7 @@ SlotMachine_CheckForMatches:
 	ld h, [hl]
 	ld l, a
 	ld de, wStringBuffer
-	ld bc, 4
+	ld bc, 4 ; every SlotReward*Text is at most 4 bytes
 	call CopyData
 	pop hl
 	ld de, .flashScreenLoop
diff --git a/home/trainers.asm b/home/trainers.asm
index ab8d5fff..f00c4df9 100644
--- a/home/trainers.asm
+++ b/home/trainers.asm
@@ -31,7 +31,7 @@ ExecuteCurMapScriptInTable::
 LoadGymLeaderAndCityName::
 	push de
 	ld de, wGymCityName
-	ld bc, $11
+	ld bc, GYM_CITY_LENGTH
 	call CopyData   ; load city name
 	pop hl
 	ld de, wGymLeaderName
diff --git a/ram/vram.asm b/ram/vram.asm
index fafb5d8e..0819fe0a 100644
--- a/ram/vram.asm
+++ b/ram/vram.asm
@@ -12,8 +12,8 @@ NEXTU
 ; battle/menu
 vSprites::  ds $80 tiles
 vFont::     ds $80 tiles
-vFrontPic:: ds 7 * 7 tiles
-vBackPic::  ds 7 * 7 tiles
+vFrontPic:: ds PIC_SIZE tiles
+vBackPic::  ds PIC_SIZE tiles
 
 NEXTU
 ; overworld
@@ -25,7 +25,7 @@ NEXTU
 ; title
 	ds $80 tiles
 vTitleLogo::  ds $80 tiles
-	ds 7 * 7 tiles
+	ds PIC_SIZE tiles
 vTitleLogo2:: ds 30 tiles
 
 ENDU
diff --git a/ram/wram.asm b/ram/wram.asm
index ff7d10ae..0b00d272 100644
--- a/ram/wram.asm
+++ b/ram/wram.asm
@@ -191,7 +191,7 @@ wOverworldMap:: ds 1300
 wOverworldMapEnd::
 
 NEXTU
-wTempPic:: ds 7 * 7 tiles
+wTempPic:: ds PIC_SIZE tiles
 ENDU
 
 
@@ -688,7 +688,11 @@ NEXTU
 	ds 1
 ; difference in X between the next ball and the current one
 wHUDPokeballGfxOffsetX:: db
-wHUDGraphicsTiles:: ds 3
+wHUDGraphicsTiles::
+wHUDUnusedTopTile:: db
+wHUDCornerTile:: db
+wHUDTriangleTile:: db
+wHUDGraphicsTilesEnd::
 
 NEXTU
 ; the level of the mon at the time it entered day care
@@ -1079,7 +1083,7 @@ wExpAmountGained:: dw
 wGainBoostedExp:: db
 ENDU
 
-wGymCityName:: ds 17
+wGymCityName:: ds GYM_CITY_LENGTH
 
 wGymLeaderName:: ds NAME_LENGTH