Add Experience Bar

engine/battle/core.asm

@@ -1823,6 +1823,7 @@ DrawPlayerHUDAndHPBar:
 	hlcoord 10, 7
 	call CenterMonName
 	call PlaceString
+	callfar PrintEXPBar
 	ld hl, wBattleMonSpecies
 	ld de, wLoadedMon
 	ld bc, wBattleMonDVs - wBattleMonSpecies

engine/battle/experience.asm

@@ -151,6 +151,7 @@ GainExperience:
 	xor a ; PLAYER_PARTY_DATA
 	ld [wMonDataLocation], a
 	call LoadMonData
+	call AnimateEXPBar
 	pop hl
 	ld bc, wPartyMon1Level - wPartyMon1Exp
 	add hl, bc
@@ -160,6 +161,7 @@ GainExperience:
 	ld a, [hl] ; current level
 	cp d
 	jp z, .nextMon ; if level didn't change, go to next mon
+	call KeepEXPBarFull
 	ld a, [wCurEnemyLevel]
 	push af
 	push hl
@@ -245,6 +247,7 @@ GainExperience:
 	xor a ; PLAYER_PARTY_DATA
 	ld [wMonDataLocation], a
 	call LoadMonData
+	call AnimateEXPBarAgain
 	ld d, $1
 	callfar PrintStatsBox
 	call WaitForTextScrollButtonPress

engine/gfx/exp_bar.asm

@@ -0,0 +1,247 @@
+DEF EXP_BAR_BASE_TILE_ID EQU $c0
+
+PrintEXPBar:
+	call CalcEXPBarPixelLength
+	ldh a, [hQuotient + 3] ; pixel length
+	ld [wEXPBarPixelLength], a
+	ld b, a
+	ld c, 8
+	ld d, 8
+	hlcoord 17, 11
+.loop
+	ld a, b
+	sub c
+	jr nc, .skip
+	ld c, b
+	jr .loop
+.skip
+	ld b, a
+	ld a, EXP_BAR_BASE_TILE_ID
+	add c
+.loop2
+	ld [hld], a
+	dec d
+	ret z
+	ld a, b
+	and a
+	jr nz, .loop
+	ld a, EXP_BAR_BASE_TILE_ID
+	jr .loop2
+
+CalcEXPBarPixelLength:
+	ld hl, wEXPBarKeepFullFlag
+	bit 0, [hl]
+	jr z, .start
+	res 0, [hl]
+	ld a, 8 * 8
+	ldh [hQuotient + 3], a
+	ret
+
+.start
+	; get the base exp needed for the current level
+	ld a, [wPlayerBattleStatus3]
+	ld hl, wBattleMonSpecies
+	bit TRANSFORMED, a
+	jr z, .skip
+	ld hl, wPartyMon1
+	call BattleMonPartyAttr
+.skip
+	ld a, [hl]
+	ld [wCurSpecies], a
+	call GetMonHeader
+	ld a, [wBattleMonLevel]
+	ld d, a
+	callfar CalcExperience
+	ld hl, hMultiplicand
+	ld de, wEXPBarBaseEXP
+	ld a, [hli]
+	ld [de], a
+	inc de
+	ld a, [hli]
+	ld [de], a
+	inc de
+	ld a, [hl]
+	ld [de], a
+
+	; get the exp needed to gain a level
+	ld a, [wBattleMonLevel]
+	ld d, a
+	inc d
+	callfar CalcExperience
+
+	; get the address of the active Pokemon's current experience
+	ld hl, wPartyMon1Exp
+	call BattleMonPartyAttr
+
+	; current exp - base exp
+	ld b, h
+	ld c, l
+	ld hl, wEXPBarBaseEXP
+	ld de, wEXPBarCurEXP
+	call SubThreeByteNum
+
+	; exp needed - base exp
+	ld bc, hMultiplicand
+	ld hl, wEXPBarBaseEXP
+	ld de, wEXPBarNeededEXP
+	call SubThreeByteNum
+
+	; make the divisor an 8-bit number
+	ld hl, wEXPBarNeededEXP
+	ld de, wEXPBarCurEXP + 1
+	ld a, [hli]
+	and a
+	jr z, .twoBytes
+	ld a, [hli]
+	ld [hld], a
+	dec hl
+	ld a, [hli]
+	ld [hld], a
+	ld a, [de]
+	inc de
+	ld [de], a
+	dec de
+	dec de
+	ld a, [de]
+	inc de
+	ld [de], a
+	dec de
+	xor a
+	ld [hli], a
+	ld [de], a
+	inc de
+.twoBytes
+	ld a, [hl]
+	and a
+	jr z, .oneByte
+	srl a
+	ld [hli], a
+	ld a, [hl]
+	rr a
+	ld [hld], a
+	ld a, [de]
+	srl a
+	ld [de], a
+	inc de
+	ld a, [de]
+	rr a
+	ld [de], a
+	dec de
+	jr .twoBytes
+.oneByte
+
+	; current exp * (8 tiles * 8 pixels)
+	ld hl, hMultiplicand
+	ld de, wEXPBarCurEXP
+	ld a, [de]
+	inc de
+	ld [hli], a
+	ld a, [de]
+	inc de
+	ld [hli], a
+	ld a, [de]
+	ld [hl], a
+	ld a, 8 * 8
+	ldh [hMultiplier], a
+	call Multiply
+
+	; product / needed exp = pixel length
+	ld a, [wEXPBarNeededEXP + 2]
+	ldh [hDivisor], a
+	ld b, 4
+	jp Divide
+
+; calculates the three byte number starting at [bc]
+; minus the three byte number starting at [hl]
+; and stores it into the three bytes starting at [de]
+; assumes that [hl] is smaller than [bc]
+SubThreeByteNum:
+	call .subByte
+	call .subByte
+.subByte
+	ld a, [bc]
+	inc bc
+	sub [hl]
+	inc hl
+	ld [de], a
+	jr nc, .noCarry
+	dec de
+	ld a, [de]
+	dec a
+	ld [de], a
+	inc de
+.noCarry
+	inc de
+	ret
+
+; return the address of the BattleMon's party struct attribute in hl
+BattleMonPartyAttr:
+	ld a, [wPlayerMonNumber]
+	ld bc, wPartyMon2 - wPartyMon1
+	jp AddNTimes
+
+AnimateEXPBarAgain:
+	call IsCurrentMonBattleMon
+	ret nz
+	xor a
+	ld [wEXPBarPixelLength], a
+	hlcoord 17, 11
+	ld a, EXP_BAR_BASE_TILE_ID
+	ld c, 8
+.loop
+	ld [hld], a
+	dec c
+	jr nz, .loop
+AnimateEXPBar:
+	call IsCurrentMonBattleMon
+	ret nz
+	ld a, SFX_HEAL_HP
+	call PlaySoundWaitForCurrent
+	call CalcEXPBarPixelLength
+	ld hl, wEXPBarPixelLength
+	ld a, [hl]
+	ld b, a
+	ldh a, [hQuotient + 3]
+	ld [hl], a
+	sub b
+	jr z, .done
+	ld b, a
+	ld c, 8
+	hlcoord 17, 11
+.loop1
+	ld a, [hl]
+	cp EXP_BAR_BASE_TILE_ID + 8
+	jr nz, .loop2
+	dec hl
+	dec c
+	jr z, .done
+	jr .loop1
+.loop2
+	inc a
+	ld [hl], a
+	call DelayFrame
+	dec b
+	jr z, .done
+	jr .loop1
+.done
+	ld bc, 8
+	hlcoord 10, 11
+	ld de, wTileMapBackup + 10 + 11 * 20
+	call CopyData
+	ld c, 32
+	jp DelayFrames
+
+KeepEXPBarFull:
+	call IsCurrentMonBattleMon
+	ret nz
+	ld a, [wEXPBarKeepFullFlag]
+	set 0, a
+	ld [wEXPBarKeepFullFlag], a
+	ret
+
+IsCurrentMonBattleMon:
+	ld a, [wPlayerMonNumber]
+	ld b, a
+	ld a, [wWhichPokemon]
+	cp b
+	ret

gfx/font.asm

@@ -29,3 +29,6 @@ WorldMapTileGraphicsEnd:
 
 PlayerCharacterTitleGraphics: INCBIN "gfx/title/player.2bpp"
 PlayerCharacterTitleGraphicsEnd:
+
+EXPBarGraphics::  INCBIN "gfx/battle/exp_bar.2bpp"
+EXPBarGraphicsEnd::

home/load_font.asm

@@ -31,17 +31,30 @@ LoadTextBoxTilePatterns::
 	jp CopyVideoData ; if LCD is on, transfer during V-blank
 
 LoadHpBarAndStatusTilePatterns::
-	ldh a, [rLCDC]
-	bit rLCDC_ENABLE, a
-	jr nz, .on
-.off
-	ld hl, HpBarAndStatusGraphics
-	ld de, vChars2 tile $62
-	ld bc, HpBarAndStatusGraphicsEnd - HpBarAndStatusGraphics
-	ld a, BANK(HpBarAndStatusGraphics)
-	jp FarCopyData2 ; if LCD is off, transfer all at once
-.on
 	ld de, HpBarAndStatusGraphics
 	ld hl, vChars2 tile $62
 	lb bc, BANK(HpBarAndStatusGraphics), (HpBarAndStatusGraphicsEnd - HpBarAndStatusGraphics) / $10
-	jp CopyVideoData ; if LCD is on, transfer during V-blank
+	call GoodCopyVideoData
+	ld de, EXPBarGraphics
+	ld hl, vChars1 tile $40
+	lb bc, BANK(EXPBarGraphics), (EXPBarGraphicsEnd - EXPBarGraphics) / $10
+	jp GoodCopyVideoData
+
+GoodCopyVideoData:
+	ldh a, [rLCDC]
+	bit rLCDC_ENABLE, a
+	jp nz, CopyVideoData ; if LCD is on, transfer during V-blank
+	ld a, b
+	push hl
+	push de
+	ld h, 0
+	ld l, c
+	add hl, hl
+	add hl, hl
+	add hl, hl
+	add hl, hl
+	ld b, h
+	ld c, l
+	pop hl
+	pop de
+	jp FarCopyData2 ; if LCD is off, transfer all at once

main.asm

@@ -251,6 +251,7 @@ INCLUDE "engine/events/hidden_objects/indigo_plateau_hq.asm"
 SECTION "Battle Engine 9", ROMX
 
 INCLUDE "engine/battle/experience.asm"
+INCLUDE "engine/gfx/exp_bar.asm"
 
 
 SECTION "Diploma", ROMX

ram/wram.asm

@@ -2226,6 +2226,12 @@ wBoxMonNicksEnd::
 
 wBoxDataEnd::
 
+wEXPBarPixelLength::  ds 1
+wEXPBarBaseEXP::      ds 3
+wEXPBarCurEXP::       ds 3
+wEXPBarNeededEXP::    ds 3
+wEXPBarKeepFullFlag:: ds 1
+
 
 SECTION "Stack", WRAM0