Pull a lot of engine out of main.asm

engine/overworld/hidden_items.asm

@@ -0,0 +1,168 @@
+HiddenItems: ; 76688 (1d:6688)
+	ld hl, HiddenItemCoords
+	call Func_76857
+	ld [$cd41], a
+	ld hl, $d6f0
+	ld a, [$cd41]
+	ld c, a
+	ld b, $2
+	ld a, $10
+	call Predef
+	ld a, c
+	and a
+	ret nz
+	call EnableAutoTextBoxDrawing
+	ld a, $1
+	ld [$cc3c], a
+	ld a, [$cd3d] ; item ID
+	ld [$d11e], a
+	call GetItemName
+	ld a, $24
+	jp PrintPredefTextID
+
+INCLUDE "data/hidden_item_coords.asm"
+
+FoundHiddenItemText: ; 7675b (1d:675b)
+; XXX where is the pointer to this?
+	TX_FAR _FoundHiddenItemText
+	db $8
+	ld a, [$cd3d] ; item ID
+	ld b, a
+	ld c, 1
+	call GiveItem
+	jr nc, .BagFull
+	ld hl, $d6f0
+	ld a, [$cd41]
+	ld c, a
+	ld b, $1
+	ld a, $10
+	call Predef
+	ld a, (SFX_02_3b - SFX_Headers_02) / 3
+	call PlaySoundWaitForCurrent ; play sound
+	call WaitForSoundToFinish ; wait for sound to finish playing
+	jp TextScriptEnd
+.BagFull
+	call WaitForTextScrollButtonPress ; wait for button press
+	xor a
+	ld [$cc3c], a
+	ld hl, HiddenItemBagFullText
+	call PrintText
+	jp TextScriptEnd
+
+HiddenItemBagFullText: ; 76794 (1d:6794)
+	TX_FAR _HiddenItemBagFullText
+	db "@"
+
+HiddenCoins: ; 76799 (1d:6799)
+	ld b, COIN_CASE
+	ld a, $1c
+	call Predef
+	ld a, b
+	and a
+	ret z
+	ld hl, HiddenCoinCoords
+	call Func_76857
+	ld [$cd41], a
+	ld hl, $d6fe
+	ld a, [$cd41]
+	ld c, a
+	ld b, $2
+	ld a, $10
+	call Predef
+	ld a, c
+	and a
+	ret nz
+	xor a
+	ld [$ff9f], a
+	ld [$ffa0], a
+	ld [$ffa1], a
+	ld a, [$cd3d]
+	sub COIN
+	cp 10
+	jr z, .bcd10
+	cp 20
+	jr z, .bcd20
+	cp 40
+	jr z, .bcd20
+	jr .bcd100
+.bcd10
+	ld a, $10
+	ld [$ffa1], a
+	jr .bcddone
+.bcd20
+	ld a, $20
+	ld [$ffa1], a
+	jr .bcddone
+.bcd40 ; due to a typo, this is never used
+	ld a, $40
+	ld [$ffa1], a
+	jr .bcddone
+.bcd100
+	ld a, $1
+	ld [$ffa0], a
+.bcddone
+	ld de, $d5a5
+	ld hl, $ffa1
+	ld c, $2
+	ld a, $b
+	call Predef
+	ld hl, $d6fe
+	ld a, [$cd41]
+	ld c, a
+	ld b, $1
+	ld a, $10
+	call Predef
+	call EnableAutoTextBoxDrawing
+	ld a, [wPlayerCoins]
+	cp $99
+	jr nz, .RoomInCoinCase
+	ld a, [wPlayerCoins + 1]
+	cp $99
+	jr nz, .RoomInCoinCase
+	ld a, $2c
+	jr .done
+.RoomInCoinCase
+	ld a, $2b
+.done
+	jp PrintPredefTextID
+
+INCLUDE "data/hidden_coins.asm"
+
+FoundHiddenCoinsText: ; 76847 (1d:6847)
+	TX_FAR _FoundHiddenCoinsText
+	db $10,"@"
+
+DroppedHiddenCoinsText: ; 7684d (1d:684d)
+	TX_FAR _FoundHiddenCoins2Text
+	db $10
+	TX_FAR _DroppedHiddenCoinsText
+	db "@"
+
+Func_76857: ; 76857 (1d:6857)
+	ld a, [$cd40]
+	ld d, a
+	ld a, [$cd41]
+	ld e, a
+	ld a, [W_CURMAP]
+	ld b, a
+	ld c, $ff
+.loop
+	inc c
+	ld a, [hli]
+	cp $ff ; end of the list?
+	ret z  ; if so, we're done here
+	cp b
+	jr nz, .asm_76877 ; 0x7686b $a
+	ld a, [hli]
+	cp d
+	jr nz, .asm_76878 ; 0x7686f $7
+	ld a, [hli]
+	cp e
+	jr nz, .loop
+	ld a, c
+	ret
+.asm_76877
+	inc hl
+.asm_76878
+	inc hl
+	jr .loop