Split up engine/events/hidden_object_functions

1 files changed, 169 insertions, 0 deletions

diff --git a/engine/events/hidden_objects/vermilion_gym_trash.asm b/engine/events/hidden_objects/vermilion_gym_trash.asm
new file mode 100644
index 00000000..c2d22cd5
--- /dev/null
+++ b/engine/events/hidden_objects/vermilion_gym_trash.asm
@@ -0,0 +1,169 @@
+PrintTrashText:
+	call EnableAutoTextBoxDrawing
+	tx_pre_jump VermilionGymTrashText
+
+VermilionGymTrashText::
+	TX_FAR _VermilionGymTrashText
+	db "@"
+
+GymTrashScript:
+	call EnableAutoTextBoxDrawing
+	ld a, [wHiddenObjectFunctionArgument]
+	ld [wGymTrashCanIndex], a
+
+; Don't do the trash can puzzle if it's already been done.
+	CheckEvent EVENT_2ND_LOCK_OPENED
+	jr z, .ok
+
+	tx_pre_jump VermilionGymTrashText
+
+.ok
+	CheckEventReuseA EVENT_1ST_LOCK_OPENED
+	jr nz, .trySecondLock
+
+	ld a, [wFirstLockTrashCanIndex]
+	ld b, a
+	ld a, [wGymTrashCanIndex]
+	cp b
+	jr z, .openFirstLock
+
+	tx_pre_id VermilionGymTrashText
+	jr .done
+
+.openFirstLock
+; Next can is trying for the second switch.
+	SetEvent EVENT_1ST_LOCK_OPENED
+
+	ld hl, GymTrashCans
+	ld a, [wGymTrashCanIndex]
+	; * 5
+	ld b, a
+	add a
+	add a
+	add b
+
+	ld d, 0
+	ld e, a
+	add hl, de
+	ld a, [hli]
+
+; There is a bug in this code. It should calculate a value in the range [0, 3]
+; but if the mask and random number don't have any 1 bits in common, then
+; the result of the AND will be 0. When 1 is subtracted from that, the value
+; will become $ff. This will result in 255 being added to hl, which will cause
+; hl to point to one of the zero bytes that pad the end of the ROM bank.
+; Trash can 0 was intended to be able to have the second lock only when the
+; first lock was in trash can 1 or 3. However, due to this bug, trash can 0 can
+; have the second lock regardless of which trash can had the first lock.
+
+	ld [hGymTrashCanRandNumMask], a
+	push hl
+	call Random
+	swap a
+	ld b, a
+	ld a, [hGymTrashCanRandNumMask]
+	and b
+	dec a
+	pop hl
+
+	ld d, 0
+	ld e, a
+	add hl, de
+	ld a, [hl]
+	and $f
+	ld [wSecondLockTrashCanIndex], a
+
+	tx_pre_id VermilionGymTrashSuccessText1
+	jr .done
+
+.trySecondLock
+	ld a, [wSecondLockTrashCanIndex]
+	ld b, a
+	ld a, [wGymTrashCanIndex]
+	cp b
+	jr z, .openSecondLock
+
+; Reset the cans.
+	ResetEvent EVENT_1ST_LOCK_OPENED
+	call Random
+
+	and $e
+	ld [wFirstLockTrashCanIndex], a
+
+	tx_pre_id VermilionGymTrashFailText
+	jr .done
+
+.openSecondLock
+; Completed the trash can puzzle.
+	SetEvent EVENT_2ND_LOCK_OPENED
+	ld hl, wCurrentMapScriptFlags
+	set 6, [hl]
+
+	tx_pre_id VermilionGymTrashSuccessText3
+
+.done
+	jp PrintPredefTextID
+
+GymTrashCans:
+; byte 0: mask for random number
+; bytes 1-4: indices of the trash cans that can have the second lock
+;            (but see the comment above explaining a bug regarding this)
+; Note that the mask is simply the number of valid trash can indices that
+; follow. The remaining bytes are filled with 0 to pad the length of each entry
+; to 5 bytes.
+	db 2,  1,  3,  0,  0 ; 0
+	db 3,  0,  2,  4,  0 ; 1
+	db 2,  1,  5,  0,  0 ; 2
+	db 3,  0,  4,  6,  0 ; 3
+	db 4,  1,  3,  5,  7 ; 4
+	db 3,  2,  4,  8,  0 ; 5
+	db 3,  3,  7,  9,  0 ; 6
+	db 4,  4,  6,  8, 10 ; 7
+	db 3,  5,  7, 11,  0 ; 8
+	db 3,  6, 10, 12,  0 ; 9
+	db 4,  7,  9, 11, 13 ; 10
+	db 3,  8, 10, 14,  0 ; 11
+	db 2,  9, 13,  0,  0 ; 12
+	db 3, 10, 12, 14,  0 ; 13
+	db 2, 11, 13,  0,  0 ; 14
+
+VermilionGymTrashSuccessText1::
+	TX_FAR _VermilionGymTrashSuccessText1
+	TX_ASM
+	call WaitForSoundToFinish
+	ld a, SFX_SWITCH
+	call PlaySound
+	call WaitForSoundToFinish
+	jp TextScriptEnd
+
+; unused
+VermilionGymTrashSuccessText2::
+	TX_FAR _VermilionGymTrashSuccessText2
+	db "@"
+
+; unused
+VermilionGymTrashSuccesPlaySfx:
+	TX_ASM
+	call WaitForSoundToFinish
+	ld a, SFX_SWITCH
+	call PlaySound
+	call WaitForSoundToFinish
+	jp TextScriptEnd
+
+VermilionGymTrashSuccessText3::
+	TX_FAR _VermilionGymTrashSuccessText3
+	TX_ASM
+	call WaitForSoundToFinish
+	ld a, SFX_GO_INSIDE
+	call PlaySound
+	call WaitForSoundToFinish
+	jp TextScriptEnd
+
+VermilionGymTrashFailText::
+	TX_FAR _VermilionGymTrashFailText
+	TX_ASM
+	call WaitForSoundToFinish
+	ld a, SFX_DENIED
+	call PlaySound
+	call WaitForSoundToFinish
+	jp TextScriptEnd