1 files changed, 219 insertions, 0 deletions
diff --git a/engine/bg_map_attributes.asm b/engine/bg_map_attributes.asm
new file mode 100644
index 00000000..4c50bcf8
--- /dev/null
+++ b/engine/bg_map_attributes.asm
@@ -0,0 +1,219 @@
+INCLUDE "data/bg_map_attributes.asm"
+
+LoadBGMapAttributes::
+	ld hl, BGMapAttributesPointers
+	ld a, c ; c = which packet
+	push af ; save for later (to determine if we're handling the trainer card or party menu)
+	dec a         ; read this code as:
+	add a         ;	dec a
+	ld e, a       ; add a
+	xor a         ; ld e, a
+	ld d, a       ; ld d, 0
+	add hl, de    ; add hl, de
+	ld a, [hli]   ; ld a, [hli]
+	ld e, a       ; ld h, [hl]
+	ld a, [hl]    ; ld l, a
+	ld h, a
+	ld a, e
+	ld l, a
+
+	di
+	ld a, $1
+	ldh [rVBK], a
+	push hl
+	ld a, [hl]
+	ld c, a ; save attribute count for later
+	ld de, $10
+	add hl, de
+	ld a, h
+	ldh [rHDMA1], a
+	ld a, l
+	ldh [rHDMA2], a
+	ld de, vBGMap0
+	ld a, d
+	ldh [rHDMA3], a
+	ld a, e
+	ldh [rHDMA4], a
+
+	ldh a, [rLCDC]
+	and rLCDC_ENABLE_MASK ; is LCD off?
+	jr z, .lcdOff ; if off, transfer immediately
+; wait for VBlank if LCD is on
+.waitForVBlankLoop1
+	ldh a, [rLY]
+	cp $90
+	jr nz, .waitForVBlankLoop1
+.waitForAccessibleVRAMLoop1
+	ldh a, [rSTAT]
+	and %10 ; are we in HBlank or VBlank?
+	jr nz, .waitForAccessibleVRAMLoop1 ; loop until we're in a safe period to transfer to VRAM
+.lcdOff
+	ld a, c ; number of BG attributes to transfer, plus 1 times 16
+	ldh [rHDMA5], a ; initiate transfer
+	call Func_3082 ; update audio so it doesn't "lag"
+	pop hl
+	ld a, [hli]
+	ld c, a     ; number of BG attributes to transfer, plus 1 times 16
+	ld a, [hli]
+	ld e, a
+	ld a, [hli]
+	ld d, a    ; offset of the attributes
+	add hl, de ; hl = new pointer
+	ld a, h
+	ldh [rHDMA1], a
+	ld a, l
+	ldh [rHDMA2], a
+	ld de, vBGMap1 ; copy to vBGMap1
+	ld a, d
+	ldh [rHDMA3], a
+	ld a, e
+	ldh [rHDMA4], a
+; LCD check again
+	ldh a, [rLCDC]
+	and rLCDC_ENABLE_MASK ; is LCD off?
+	jr z, .lcdOff2 ; if off, transfer immediately
+; wait for VBlank if LCD is on
+.waitForVBlankLoop2
+	ldh a, [rLY]
+	cp $90
+	jr nz, .waitForVBlankLoop2
+.waitForAccessibleVRAMLoop2
+	ldh a, [rSTAT]
+	and %10 ; are we in HBlank or VBlank?
+	jr nz, .waitForAccessibleVRAMLoop2 ; loop until we're in a safe period to transfer to VRAM
+.lcdOff2
+	ld a, c
+	ldh [rHDMA5], a
+	pop af
+	dec a
+	dec a
+	dec a
+	dec a
+	jr nz, .checkIfHandlingPartyMenu
+	call HandleBadgeFaceAttributes
+	jr .done
+.checkIfHandlingPartyMenu
+	dec a
+	call z, HandlePartyHPBarAttributes
+.done
+	call Func_3082
+	ldh a, [rIF]
+	res VBLANK, a
+	ldh [rIF], a
+	xor a
+	ldh [rVBK], a
+	ei
+	ret
+
+BGMapAttributesPointers:
+	dw BGMapAttributes_Unknown1
+	dw BGMapAttributes_Unknown2
+	dw BGMapAttributes_GameFreakIntro
+	dw BGMapAttributes_TrainerCard
+	dw BGMapAttributes_PartyMenu
+	dw BGMapAttributes_NidorinoIntro
+	dw BGMapAttributes_TitleScreen
+	dw BGMapAttributes_Slots
+	dw BGMapAttributes_Pokedex
+	dw BGMapAttributes_StatusScreen
+	dw BGMapAttributes_Battle
+	dw BGMapAttributes_WholeScreen
+	dw BGMapAttributes_Unknown13
+
+HandleBadgeFaceAttributes:
+; zero out the attributes if the player doesn't have the respective badge
+; BOULDERBADGE
+	ld hl, vBGMap1 + $183
+	ld de, wTrainerCardBadgeAttributes + 6 * 0
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+; CASCADEBADGE
+	ld hl, vBGMap1 + $187
+	ld de, wTrainerCardBadgeAttributes + 6 * 1
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+; THUNDERBADGE
+	ld hl, vBGMap1 + $18b
+	ld de, wTrainerCardBadgeAttributes + 6 * 2
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+; RAINBOWBADGE
+	ld hl, vBGMap1 + $18f
+	ld de, wTrainerCardBadgeAttributes + 6 * 3
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+; SOULBADGE
+	ld hl, vBGMap1 + $1e3
+	ld de, wTrainerCardBadgeAttributes + 6 * 6
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+; MARSHBADGE
+	ld hl, vBGMap1 + $1e7
+	ld de, wTrainerCardBadgeAttributes + 6 * 7
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+; VOLCANOBADGE
+	ld hl, vBGMap1 + $1eb
+	ld de, wTrainerCardBadgeAttributes + 6 * 8
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+; EARTHBADGE
+	ld hl, vBGMap1 + $1ef
+	ld de, wTrainerCardBadgeAttributes + 6 * 9
+	ld a, [de]
+	and a
+	call z, ZeroOutCurrentBadgeAttributes
+	ret
+
+ZeroOutCurrentBadgeAttributes:
+	push hl
+	xor a
+	ld [hli], a
+	ld [hl], a
+	ld bc, $1f
+	add hl, bc
+	ld [hli], a
+	ld [hl], a
+	pop hl
+	ret
+
+HandlePartyHPBarAttributes:
+; hp bars require 3 (green, orange, red) colours, when there are only 2 "free" colours per palette
+; therefore, we must transfer individual bg attributes where the locations of the hp bars are in vram
+	ld hl, vBGMap1 + $25 ; location of start of the HP bar in vram
+	ld de, wPartyHPBarAttributes
+	ld c, PARTY_LENGTH
+.loop
+	push bc
+	push hl
+	ld a, [de]
+	and $3 ; 4 possible palettes
+	rept 7 ; hp bar length in tiles
+	ld [hli], a
+	endr
+	pop hl
+	ld bc, $40 ; get 2nd party location
+	add hl, bc
+	push hl
+
+	push de ; (inefficiently) copy de to hl
+	pop hl
+
+	ld bc, $6
+	add hl, bc ; get the next palette
+
+	push hl
+	pop de ; copy back to de
+
+	pop hl
+	pop bc
+	dec c
+	jr nz, .loop
+	ret