start decompiling item_use.c (#144)

* begin decompiling item_use.c

* decompile more of item_use.c

* commit what I have currently

* formatting

6 files changed, 417 insertions, 852 deletions

diff --git a/asm/item_use.s b/asm/item_use.s
index 65953583e..8a1bf766e 100644
--- a/asm/item_use.s
+++ b/asm/item_use.s
@@ -6,853 +6,6 @@
 
 	.text
 
-	thumb_func_start sub_80C8FAC
-sub_80C8FAC: @ 80C8FAC
-	push {r4,lr}
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldr r1, _080C8FD0 @ =gScriptItemId
-	ldrh r0, [r1]
-	cmp r0, 0xAF
-	bne _080C8FD8
-	ldr r1, _080C8FD4 @ =gTasks
-	lsls r2, r4, 2
-	adds r0, r2, r4
-	lsls r0, 3
-	adds r0, r1
-	ldrh r0, [r0, 0x26]
-	subs r0, 0x1
-	lsls r0, 24
-	lsrs r3, r0, 24
-	b _080C8FE6
-	.align 2, 0
-_080C8FD0: .4byte gScriptItemId
-_080C8FD4: .4byte gTasks
-_080C8FD8:
-	ldrh r0, [r1]
-	bl ItemId_GetType
-	subs r0, 0x1
-	lsls r0, 24
-	lsrs r3, r0, 24
-	lsls r2, r4, 2
-_080C8FE6:
-	ldr r0, _080C9008 @ =gTasks
-	adds r1, r2, r4
-	lsls r1, 3
-	adds r1, r0
-	ldr r2, _080C900C @ =gUnknown_083D61E4
-	lsls r0, r3, 2
-	adds r0, r2
-	ldr r2, [r0]
-	lsrs r0, r2, 16
-	strh r0, [r1, 0x18]
-	strh r2, [r1, 0x1A]
-	ldr r0, _080C9010 @ =sub_80A5B00
-	str r0, [r1]
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9008: .4byte gTasks
-_080C900C: .4byte gUnknown_083D61E4
-_080C9010: .4byte sub_80A5B00
-	thumb_func_end sub_80C8FAC
-
-	thumb_func_start unknown_ItemMenu_Confirm
-unknown_ItemMenu_Confirm: @ 80C9014
-	push {lr}
-	sub sp, 0x4
-	lsls r0, 24
-	lsrs r0, 24
-	bl sub_80C8FAC
-	movs r0, 0x1
-	negs r0, r0
-	movs r1, 0
-	str r1, [sp]
-	movs r2, 0
-	movs r3, 0x10
-	bl BeginNormalPaletteFade
-	add sp, 0x4
-	pop {r0}
-	bx r0
-	thumb_func_end unknown_ItemMenu_Confirm
-
-	thumb_func_start sub_80C9038
-sub_80C9038: @ 80C9038
-	push {lr}
-	lsls r0, 24
-	lsrs r0, 24
-	bl sub_80C8FAC
-	movs r0, 0x1
-	movs r1, 0
-	bl fade_screen
-	pop {r0}
-	bx r0
-	thumb_func_end sub_80C9038
-
-	thumb_func_start SetUpItemUseOnFieldCallback
-SetUpItemUseOnFieldCallback: @ 80C9050
-	push {lr}
-	lsls r0, 24
-	lsrs r2, r0, 24
-	ldr r1, _080C9078 @ =gTasks
-	lsls r0, r2, 2
-	adds r0, r2
-	lsls r0, 3
-	adds r0, r1
-	movs r1, 0xC
-	ldrsh r0, [r0, r1]
-	cmp r0, 0x1
-	beq _080C9084
-	ldr r1, _080C907C @ =gUnknown_0300485C
-	ldr r0, _080C9080 @ =sub_80A5CC4
-	str r0, [r1]
-	adds r0, r2, 0
-	bl unknown_ItemMenu_Confirm
-	b _080C908E
-	.align 2, 0
-_080C9078: .4byte gTasks
-_080C907C: .4byte gUnknown_0300485C
-_080C9080: .4byte sub_80A5CC4
-_080C9084:
-	ldr r0, _080C9094 @ =gUnknown_03005D00
-	ldr r1, [r0]
-	adds r0, r2, 0
-	bl _call_via_r1
-_080C908E:
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9094: .4byte gUnknown_03005D00
-	thumb_func_end SetUpItemUseOnFieldCallback
-
-	thumb_func_start sub_80C9098
-sub_80C9098: @ 80C9098
-	push {r4-r6,lr}
-	adds r4, r1, 0
-	adds r1, r2, 0
-	lsls r0, 24
-	lsrs r6, r0, 24
-	lsls r4, 24
-	lsrs r4, 24
-	ldr r5, _080C90CC @ =gStringVar4
-	adds r0, r5, 0
-	bl StringExpandPlaceholders
-	cmp r4, 0
-	bne _080C90D4
-	movs r0, 0
-	movs r1, 0xD
-	movs r2, 0xD
-	movs r3, 0x14
-	bl MenuZeroFillWindowRect
-	ldr r2, _080C90D0 @ =sub_80A5C48
-	adds r0, r6, 0
-	adds r1, r5, 0
-	movs r3, 0x1
-	bl DisplayItemMessageOnField
-	b _080C90E0
-	.align 2, 0
-_080C90CC: .4byte gStringVar4
-_080C90D0: .4byte sub_80A5C48
-_080C90D4:
-	ldr r2, _080C90E8 @ =sub_80A5C9C
-	adds r0, r6, 0
-	adds r1, r5, 0
-	movs r3, 0
-	bl DisplayItemMessageOnField
-_080C90E0:
-	pop {r4-r6}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C90E8: .4byte sub_80A5C9C
-	thumb_func_end sub_80C9098
-
-	thumb_func_start DisplayDadsAdviceCannotUseItemMessage
-DisplayDadsAdviceCannotUseItemMessage: @ 80C90EC
-	push {lr}
-	lsls r0, 24
-	lsrs r0, 24
-	lsls r1, 24
-	lsrs r1, 24
-	ldr r2, _080C9100 @ =gOtherText_DadsAdvice
-	bl sub_80C9098
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9100: .4byte gOtherText_DadsAdvice
-	thumb_func_end DisplayDadsAdviceCannotUseItemMessage
-
-	thumb_func_start sub_80C9104
-sub_80C9104: @ 80C9104
-	push {lr}
-	lsls r0, 24
-	lsrs r0, 24
-	lsls r1, 24
-	lsrs r1, 24
-	ldr r2, _080C9118 @ =gOtherText_CantGetOffBike
-	bl sub_80C9098
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9118: .4byte gOtherText_CantGetOffBike
-	thumb_func_end sub_80C9104
-
-	thumb_func_start CheckIfItemIsTMHMOrEvolutionStone
-CheckIfItemIsTMHMOrEvolutionStone: @ 80C911C
-	push {r4,lr}
-	lsls r0, 16
-	lsrs r4, r0, 16
-	adds r0, r4, 0
-	bl ItemId_GetFieldFunc
-	ldr r1, _080C9134 @ =ItemUseOutOfBattle_TMHM
-	cmp r0, r1
-	bne _080C9138
-	movs r0, 0x1
-	b _080C914E
-	.align 2, 0
-_080C9134: .4byte ItemUseOutOfBattle_TMHM
-_080C9138:
-	adds r0, r4, 0
-	bl ItemId_GetFieldFunc
-	ldr r1, _080C9148 @ =ItemUseOutOfBattle_EvolutionStone
-	cmp r0, r1
-	beq _080C914C
-	movs r0, 0
-	b _080C914E
-	.align 2, 0
-_080C9148: .4byte ItemUseOutOfBattle_EvolutionStone
-_080C914C:
-	movs r0, 0x2
-_080C914E:
-	pop {r4}
-	pop {r1}
-	bx r1
-	thumb_func_end CheckIfItemIsTMHMOrEvolutionStone
-
-	thumb_func_start sub_80C9154
-sub_80C9154: @ 80C9154
-	push {r4,lr}
-	sub sp, 0x24
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldr r0, _080C9188 @ =gPaletteFade
-	ldrb r1, [r0, 0x7]
-	movs r0, 0x80
-	ands r0, r1
-	cmp r0, 0
-	bne _080C9180
-	mov r1, sp
-	ldr r0, _080C918C @ =gScriptItemId
-	ldrh r0, [r0]
-	strh r0, [r1, 0x20]
-	ldr r1, _080C9190 @ =sub_80A5D04
-	mov r0, sp
-	movs r2, 0
-	bl sub_80F890C
-	adds r0, r4, 0
-	bl DestroyTask
-_080C9180:
-	add sp, 0x24
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9188: .4byte gPaletteFade
-_080C918C: .4byte gScriptItemId
-_080C9190: .4byte sub_80A5D04
-	thumb_func_end sub_80C9154
-
-	thumb_func_start ItemUseOutOfBattle_Mail
-ItemUseOutOfBattle_Mail: @ 80C9194
-	push {r4,lr}
-	sub sp, 0x4
-	adds r4, r0, 0
-	lsls r4, 24
-	lsrs r4, 24
-	movs r0, 0x1
-	negs r0, r0
-	movs r1, 0
-	str r1, [sp]
-	movs r2, 0
-	movs r3, 0x10
-	bl BeginNormalPaletteFade
-	ldr r1, _080C91C4 @ =gTasks
-	lsls r0, r4, 2
-	adds r0, r4
-	lsls r0, 3
-	adds r0, r1
-	ldr r1, _080C91C8 @ =sub_80C9154
-	str r1, [r0]
-	add sp, 0x4
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C91C4: .4byte gTasks
-_080C91C8: .4byte sub_80C9154
-	thumb_func_end ItemUseOutOfBattle_Mail
-
-	thumb_func_start ItemUseOutOfBattle_Bike
-ItemUseOutOfBattle_Bike: @ 80C91CC
-	push {r4,r5,lr}
-	sub sp, 0x4
-	lsls r0, 24
-	lsrs r5, r0, 24
-	mov r4, sp
-	adds r4, 0x2
-	mov r0, sp
-	adds r1, r4, 0
-	bl PlayerGetDestCoords
-	mov r0, sp
-	movs r1, 0
-	ldrsh r0, [r0, r1]
-	movs r2, 0
-	ldrsh r1, [r4, r2]
-	bl MapGridGetMetatileBehaviorAt
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldr r0, _080C924C @ =0x0000082b
-	bl FlagGet
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	beq _080C9238
-	adds r0, r4, 0
-	bl MetatileBehavior_IsVerticalRail
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	beq _080C9238
-	adds r0, r4, 0
-	bl MetatileBehavior_IsHorizontalRail
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	beq _080C9238
-	adds r0, r4, 0
-	bl MetatileBehavior_IsIsolatedVerticalRail
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	beq _080C9238
-	adds r0, r4, 0
-	bl MetatileBehavior_IsIsolatedHorizontalRail
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	bne _080C9254
-_080C9238:
-	ldr r0, _080C9250 @ =gTasks
-	lsls r1, r5, 2
-	adds r1, r5
-	lsls r1, 3
-	adds r1, r0
-	ldrb r1, [r1, 0xC]
-	adds r0, r5, 0
-	bl sub_80C9104
-	b _080C928E
-	.align 2, 0
-_080C924C: .4byte 0x0000082b
-_080C9250: .4byte gTasks
-_080C9254:
-	bl sub_8053C44
-	cmp r0, 0x1
-	bne _080C927C
-	bl sub_80E5EF4
-	lsls r0, 24
-	cmp r0, 0
-	bne _080C927C
-	ldr r1, _080C9274 @ =gUnknown_03005D00
-	ldr r0, _080C9278 @ =ItemUseOnFieldCB_Bike
-	str r0, [r1]
-	adds r0, r5, 0
-	bl SetUpItemUseOnFieldCallback
-	b _080C928E
-	.align 2, 0
-_080C9274: .4byte gUnknown_03005D00
-_080C9278: .4byte ItemUseOnFieldCB_Bike
-_080C927C:
-	ldr r0, _080C9298 @ =gTasks
-	lsls r1, r5, 2
-	adds r1, r5
-	lsls r1, 3
-	adds r1, r0
-	ldrb r1, [r1, 0xC]
-	adds r0, r5, 0
-	bl DisplayDadsAdviceCannotUseItemMessage
-_080C928E:
-	add sp, 0x4
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9298: .4byte gTasks
-	thumb_func_end ItemUseOutOfBattle_Bike
-
-	thumb_func_start ItemUseOnFieldCB_Bike
-ItemUseOnFieldCB_Bike: @ 80C929C
-	push {r4,r5,lr}
-	lsls r0, 24
-	lsrs r5, r0, 24
-	ldr r4, _080C92E0 @ =gScriptItemId
-	ldrh r0, [r4]
-	bl ItemId_GetSecondaryId
-	lsls r0, 24
-	cmp r0, 0
-	bne _080C92B6
-	movs r0, 0x2
-	bl GetOnOffBike
-_080C92B6:
-	ldrh r0, [r4]
-	bl ItemId_GetSecondaryId
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	bne _080C92CA
-	movs r0, 0x4
-	bl GetOnOffBike
-_080C92CA:
-	bl sub_8064E2C
-	bl ScriptContext2_Disable
-	adds r0, r5, 0
-	bl DestroyTask
-	pop {r4,r5}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C92E0: .4byte gScriptItemId
-	thumb_func_end ItemUseOnFieldCB_Bike
-
-	thumb_func_start CanFish
-CanFish: @ 80C92E4
-	push {r4-r6,lr}
-	sub sp, 0x4
-	mov r4, sp
-	adds r4, 0x2
-	mov r0, sp
-	adds r1, r4, 0
-	bl GetXYCoordsOneStepInFrontOfPlayer
-	mov r0, sp
-	movs r1, 0
-	ldrsh r0, [r0, r1]
-	movs r2, 0
-	ldrsh r1, [r4, r2]
-	bl MapGridGetMetatileBehaviorAt
-	lsls r0, 16
-	lsrs r6, r0, 16
-	lsls r0, r6, 24
-	lsrs r5, r0, 24
-	adds r0, r5, 0
-	bl MetatileBehavior_IsWaterfall
-	lsls r0, 24
-	cmp r0, 0
-	bne _080C936C
-	movs r0, 0x10
-	bl TestPlayerAvatarFlags
-	lsls r0, 24
-	cmp r0, 0
-	bne _080C936C
-	movs r0, 0x8
-	bl TestPlayerAvatarFlags
-	lsls r0, 24
-	cmp r0, 0
-	bne _080C933C
-	bl IsPlayerFacingSurfableFishableWater
-	lsls r0, 24
-	cmp r0, 0
-	beq _080C936C
-_080C9338:
-	movs r0, 0x1
-	b _080C936E
-_080C933C:
-	adds r0, r5, 0
-	bl MetatileBehavior_IsSurfableWaterOrUnderwater
-	lsls r0, 24
-	cmp r0, 0
-	beq _080C935C
-	mov r0, sp
-	movs r1, 0
-	ldrsh r0, [r0, r1]
-	movs r2, 0
-	ldrsh r1, [r4, r2]
-	bl MapGridIsImpassableAt
-	lsls r0, 24
-	cmp r0, 0
-	beq _080C9338
-_080C935C:
-	lsls r0, r6, 24
-	lsrs r0, 24
-	bl MetatileBehavior_IsBridge
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	beq _080C9338
-_080C936C:
-	movs r0, 0
-_080C936E:
-	add sp, 0x4
-	pop {r4-r6}
-	pop {r1}
-	bx r1
-	thumb_func_end CanFish
-
-	thumb_func_start ItemUseOutOfBattle_Rod
-ItemUseOutOfBattle_Rod: @ 80C9378
-	push {r4,lr}
-	lsls r0, 24
-	lsrs r4, r0, 24
-	bl CanFish
-	cmp r0, 0x1
-	bne _080C939C
-	ldr r1, _080C9394 @ =gUnknown_03005D00
-	ldr r0, _080C9398 @ =ItemUseOnFieldCB_Rod
-	str r0, [r1]
-	adds r0, r4, 0
-	bl SetUpItemUseOnFieldCallback
-	b _080C93AE
-	.align 2, 0
-_080C9394: .4byte gUnknown_03005D00
-_080C9398: .4byte ItemUseOnFieldCB_Rod
-_080C939C:
-	ldr r0, _080C93B4 @ =gTasks
-	lsls r1, r4, 2
-	adds r1, r4
-	lsls r1, 3
-	adds r1, r0
-	ldrb r1, [r1, 0xC]
-	adds r0, r4, 0
-	bl DisplayDadsAdviceCannotUseItemMessage
-_080C93AE:
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C93B4: .4byte gTasks
-	thumb_func_end ItemUseOutOfBattle_Rod
-
-	thumb_func_start ItemUseOnFieldCB_Rod
-ItemUseOnFieldCB_Rod: @ 80C93B8
-	push {r4,lr}
-	adds r4, r0, 0
-	lsls r4, 24
-	lsrs r4, 24
-	ldr r0, _080C93DC @ =gScriptItemId
-	ldrh r0, [r0]
-	bl ItemId_GetSecondaryId
-	lsls r0, 24
-	lsrs r0, 24
-	bl StartFishing
-	adds r0, r4, 0
-	bl DestroyTask
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C93DC: .4byte gScriptItemId
-	thumb_func_end ItemUseOnFieldCB_Rod
-
-	thumb_func_start ItemUseOutOfBattle_Itemfinder
-ItemUseOutOfBattle_Itemfinder: @ 80C93E0
-	push {r4,lr}
-	adds r4, r0, 0
-	lsls r4, 24
-	lsrs r4, 24
-	movs r0, 0x27
-	bl sav12_xor_increment
-	ldr r1, _080C9400 @ =gUnknown_03005D00
-	ldr r0, _080C9404 @ =ItemUseOnFieldCB_Itemfinder
-	str r0, [r1]
-	adds r0, r4, 0
-	bl SetUpItemUseOnFieldCallback
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9400: .4byte gUnknown_03005D00
-_080C9404: .4byte ItemUseOnFieldCB_Itemfinder
-	thumb_func_end ItemUseOutOfBattle_Itemfinder
-
-	thumb_func_start ItemUseOnFieldCB_Itemfinder
-ItemUseOnFieldCB_Itemfinder: @ 80C9408
-	push {r4,lr}
-	lsls r0, 24
-	lsrs r4, r0, 24
-	ldr r0, _080C9430 @ =gMapHeader
-	ldr r0, [r0, 0x4]
-	adds r1, r4, 0
-	bl ItemfinderCheckForHiddenItems
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0x1
-	bne _080C943C
-	ldr r0, _080C9434 @ =gTasks
-	lsls r1, r4, 2
-	adds r1, r4
-	lsls r1, 3
-	adds r1, r0
-	ldr r0, _080C9438 @ =sub_80C9458
-	str r0, [r1]
-	b _080C9448
-	.align 2, 0
-_080C9430: .4byte gMapHeader
-_080C9434: .4byte gTasks
-_080C9438: .4byte sub_80C9458
-_080C943C:
-	ldr r1, _080C9450 @ =gOtherText_NoResponse
-	ldr r2, _080C9454 @ =sub_80C9520
-	adds r0, r4, 0
-	movs r3, 0
-	bl DisplayItemMessageOnField
-_080C9448:
-	pop {r4}
-	pop {r0}
-	bx r0
-	.align 2, 0
-_080C9450: .4byte gOtherText_NoResponse
-_080C9454: .4byte sub_80C9520
-	thumb_func_end ItemUseOnFieldCB_Itemfinder
-
-	thumb_func_start sub_80C9458
-sub_80C9458: @ 80C9458
-	push {r4-r7,lr}
-	mov r7, r8
-	push {r7}
-	lsls r0, 24
-	lsrs r5, r0, 24
-	lsls r6, r5, 2
-	adds r0, r6, r5
-	lsls r7, r0, 3
-	ldr r0, _080C94AC @ =gTasks + 0x8
-	mov r8, r0
-	adds r4, r7, r0
-	movs r1, 0x6
-	ldrsh r0, [r4, r1]
-	cmp r0, 0
-	bne _080C950C
-	movs r2, 0x8
-	ldrsh r0, [r4, r2]
-	cmp r0, 0x4
-	bne _080C9500
-	movs r1, 0
-	ldrsh r0, [r4, r1]
-	movs r2, 0x2
-	ldrsh r1, [r4, r2]
-	bl sub_80C9908
-	lsls r0, 24
-	lsrs r0, 24
-	cmp r0, 0
-	beq _080C94B8
-	ldr r1, _080C94B0 @ =gUnknown_083D61F0
-	subs r0, 0x1
-	adds r0, r1
-	ldrb r0, [r0]
-	bl sub_80C997C
-	mov r0, r8
-	subs r0, 0x8
-	adds r0, r7, r0
-	ldr r1, _080C94B4 @ =sub_80C99EC
-	str r1, [r0]
-	b _080C9516
-	.align 2, 0
-_080C94AC: .4byte gTasks + 0x8
-_080C94B0: .4byte gUnknown_083D61F0
-_080C94B4: .4byte sub_80C99EC
-_080C94B8:
-	bl player_get_direction_lower_nybble
-	lsls r0, 24
-	lsrs r2, r0, 24
-	movs r1, 0
-	adds r3, r6, 0
-	ldr r7, _080C94F4 @ =gUnknown_083D61F0
-	movs r6, 0x3
-_080C94C8:
-	adds r0, r1, r7
-	adds r1, 0x1
-	ldrb r0, [r0]
-	cmp r2, r0
-	bne _080C94D8
-	adds r0, r1, 0
-	ands r0, r6
-	strh r0, [r4, 0xA]
-_080C94D8:
-	lsls r0, r1, 24
-	lsrs r1, r0, 24
-	cmp r1, 0x3
-	bls _080C94C8
-	ldr r1, _080C94F8 @ =gTasks
-	adds r0, r3, r5
-	lsls r0, 3
-	adds r0, r1
-	ldr r1, _080C94FC @ =sub_80C9A38
-	str r1, [r0]
-	movs r0, 0
-	strh r0, [r4, 0x6]
-	strh r0, [r4, 0x4]
-	b _080C9516
-	.align 2, 0
-_080C94F4: .4byte gUnknown_083D61F0
-_080C94F8: .4byte gTasks
-_080C94FC: .4byte sub_80C9A38
-_080C9500:
-	movs r0, 0x48
-	bl PlaySE
-	ldrh r0, [r4, 0x8]
-	adds r0, 0x1
-	strh r0, [r4, 0x8]
-_080C950C:
-	ldrh r0, [r4, 0x6]
-	adds r0, 0x1
-	movs r1, 0x1F
-	ands r0, r1
-	strh r0, [r4, 0x6]
-_080C9516:
-	pop {r3}
-	mov r8, r3
-	pop {r4-r7}
-	pop {r0}
-	bx r0
-	thumb_func_end sub_80C9458
-
-	thumb_func_start sub_80C9520
-sub_80C9520: @ 80C9520
-	push {r4,lr}
-	adds r4, r0, 0
-	lsls r4, 24
-	lsrs r4, 24
-	movs r0, 0
-	movs r1, 0xE
-	movs r2, 0x1D
-	movs r3, 0x13
-	bl MenuZeroFillWindowRect
-	bl sub_8064E2C
-	bl ScriptContext2_Disable
-	adds r0, r4, 0
-	bl DestroyTask
-	pop {r4}
-	pop {r0}
-	bx r0
-	thumb_func_end sub_80C9520
-
-	thumb_func_start ItemfinderCheckForHiddenItems
-ItemfinderCheckForHiddenItems: @ 80C9548
-	push {r4-r7,lr}
-	mov r7, r9
-	mov r6, r8
-	push {r6,r7}
-	sub sp, 0x4
-	adds r5, r0, 0
-	lsls r1, 24
-	lsrs r6, r1, 24
-	mov r4, sp
-	adds r4, 0x2
-	mov r0, sp
-	adds r1, r4, 0
-	bl PlayerGetDestCoords
-	ldr r1, _080C9618 @ =gTasks
-	lsls r0, r6, 2
-	adds r0, r6
-	lsls r0, 3
-	adds r0, r1
-	movs r1, 0
-	strh r1, [r0, 0xC]
-	movs r3, 0
-	mov r9, r4
-	ldrb r0, [r5, 0x3]
-	cmp r3, r0
-	bge _080C95FC
-	subs r1, 0x5
-	mov r8, r1
-_080C9580:
-	lsls r3, 16
-	asrs r1, r3, 16
-	ldr r2, [r5, 0x10]
-	lsls r0, r1, 1
-	adds r0, r1
-	lsls r4, r0, 2
-	adds r1, r4, r2
-	ldrb r0, [r1, 0x5]
-	adds r7, r3, 0
-	cmp r0, 0x7
-	bne _080C95EC
-	movs r2, 0x96
-	lsls r2, 2
-	adds r0, r2, 0
-	ldrh r1, [r1, 0xA]
-	adds r0, r1
-	lsls r0, 16
-	lsrs r0, 16
-	bl FlagGet
-	lsls r0, 24
-	cmp r0, 0
-	bne _080C95EC
-	ldr r1, [r5, 0x10]
-	adds r1, r4, r1
-	ldrh r2, [r1]
-	adds r2, 0x7
-	mov r0, sp
-	ldrh r0, [r0]
-	subs r2, r0
-	ldrh r0, [r1, 0x2]
-	adds r0, 0x7
-	mov r3, r9
-	ldrh r1, [r3]
-	subs r0, r1
-	lsls r0, 16
-	lsrs r0, 16
-	lsls r2, 16
-	asrs r1, r2, 16
-	movs r3, 0xE0
-	lsls r3, 11
-	adds r2, r3
-	lsrs r2, 16
-	cmp r2, 0xE
-	bhi _080C95EC
-	lsls r0, 16
-	asrs r2, r0, 16
-	cmp r2, r8
-	blt _080C95EC
-	cmp r2, 0x5
-	bgt _080C95EC
-	adds r0, r6, 0
-	bl sub_80C9838
-_080C95EC:
-	movs r1, 0x80
-	lsls r1, 9
-	adds r0, r7, r1
-	lsrs r3, r0, 16
-	asrs r0, 16
-	ldrb r2, [r5, 0x3]
-	cmp r0, r2
-	blt _080C9580
-_080C95FC:
-	adds r0, r6, 0
-	bl sub_80C9720
-	ldr r0, _080C9618 @ =gTasks
-	lsls r1, r6, 2
-	adds r1, r6
-	lsls r1, 3
-	adds r1, r0
-	movs r3, 0xC
-	ldrsh r0, [r1, r3]
-	cmp r0, 0x1
-	beq _080C961C
-	movs r0, 0
-	b _080C961E
-	.align 2, 0
-_080C9618: .4byte gTasks
-_080C961C:
-	movs r0, 0x1
-_080C961E:
-	add sp, 0x4
-	pop {r3,r4}
-	mov r8, r3
-	mov r9, r4
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	thumb_func_end ItemfinderCheckForHiddenItems
-
 	thumb_func_start sub_80C962C
 sub_80C962C: @ 80C962C
 	push {r4-r6,lr}
diff --git a/include/asm_fieldmap.h b/include/asm_fieldmap.h
index afc1fac7c..10d8c8f6d 100644
--- a/include/asm_fieldmap.h
+++ b/include/asm_fieldmap.h
@@ -6,7 +6,7 @@ void sub_8055FC0(void);
 u8 MapGridGetZCoordAt();
 bool8 MapGridIsImpassableAt(s16, s16);
 int MapGridGetMetatileIdAt(int, int);
-int MapGridGetMetatileBehaviorAt(int x, int y); // return: (u8|u16|int) args: (int|s16|s32)
+u32 MapGridGetMetatileBehaviorAt(int x, int y); // return: (u8|u16|int) args: (int|s16|s32)
 u8 MapGridGetMetatileLayerTypeAt(/*TODO: arg types*/);
 void MapGridSetMetatileIdAt(u32, u32, u16);
 void save_serialize_map(void);
diff --git a/include/field_player_avatar.h b/include/field_player_avatar.h
index 9e2e7a489..0095c229f 100644
--- a/include/field_player_avatar.h
+++ b/include/field_player_avatar.h
@@ -71,7 +71,7 @@ u8 GetPlayerAvatarGraphicsIdByStateId(u8 a);
 // GetPlayerAvatarGenderByGraphicsId
 // PartyHasMonWithSurf
 // IsPlayerSurfingNorth
-// IsPlayerFacingSurfableFishableWater
+bool8 IsPlayerFacingSurfableFishableWater(void);
 // ClearPlayerAvatarInfo
 void SetPlayerAvatarStateMask(u8 a);
 // GetPlayerAvatarGraphicsIdByCurrentState
@@ -91,7 +91,7 @@ void InitPlayerAvatar(s16 a, s16 b, u8 c, u8 d);
 // sub_805A178
 // sub_805A1B8
 void sub_805A20C(u8 a);
-// StartFishing
+void StartFishing(u8 a);
 // Fishing1
 // Fishing2
 // Fishing3
diff --git a/include/global.fieldmap.h b/include/global.fieldmap.h
index 9bcd9c3e7..3759d9d15 100644
--- a/include/global.fieldmap.h
+++ b/include/global.fieldmap.h
@@ -58,7 +58,8 @@ struct WarpEvent
 struct CoordEvent
 {
     s16 x, y;
-    u8 filler_4[0x2];
+    u8 filler_4;
+    u8 filler_5;
     u16 trigger;
     u16 index;
     u8 filler_A[0x2];
@@ -76,7 +77,7 @@ struct BgEvent
 
 struct MapEvents
 {
-    u8 mapObjectCount;
+    u32 mapObjectCount;
     u8 warpCount;
     u8 coordEventCount;
     u8 bgEventCount;
diff --git a/ld_script.txt b/ld_script.txt
index 6ed88f4ac..2d2489b74 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -148,6 +148,7 @@ SECTIONS {
         asm/rotating_gate.o(.text);
         src/safari_zone.o(.text);
         asm/contest_link_80C857C.o(.text);
+        src/item_use.o(.text);
         asm/item_use.o(.text);
         asm/battle_anim_80CA710.o(.text);
         asm/bike.o(.text);
diff --git a/src/item_use.c b/src/item_use.c
new file mode 100644
index 000000000..fee70d7d2
--- /dev/null
+++ b/src/item_use.c
@@ -0,0 +1,410 @@
+#include "global.h"
+#include "task.h"
+#include "item.h"
+#include "palette.h"
+#include "weather.h"
+#include "string_util.h"
+#include "menu.h"
+#include "mail.h"
+#include "asm.h"
+#include "rom4.h"
+#include "metatile_behavior.h"
+#include "field_player_avatar.h"
+#include "flag.h"
+#include "map_obj_lock.h"
+#include "script.h"
+#include "field_player_avatar.h"
+#include "sound.h"
+
+extern void (* const gUnknown_083D61E4[])();
+extern void (* gUnknown_03005D00)(u8);
+extern void (* gUnknown_0300485C)(void);
+
+extern void sub_80A5B00(u8);
+extern void sub_80A5CC4(void);
+extern void sub_80C8FAC(u8);
+extern void DisplayItemMessageOnField(u8, u8*, TaskFunc, u16);
+extern void sub_80A5C48(u8);
+extern void sub_80A5C9C(u8);
+extern void ItemUseOutOfBattle_TMHM(u8);
+extern void ItemUseOutOfBattle_EvolutionStone(u8);
+extern void ItemUseOnFieldCB_Bike(u8);
+extern void ItemUseOnFieldCB_Rod(u8);
+extern void ItemUseOnFieldCB_Itemfinder(u8);
+extern void sub_80A5D04(void);
+extern bool8 sub_80E5EF4(void);
+extern void GetOnOffBike(u8);
+extern void sub_80C9458(u8);
+extern void sub_80C9520(u8);
+extern u8 sub_80C9908(s16, s16);
+extern void sub_80C997C(u8);
+extern void sub_80C99EC(u8);
+extern void sub_80C9A38(u8);
+
+extern u8 gOtherText_DadsAdvice[];
+extern u8 gOtherText_CantGetOffBike[];
+extern u8 gOtherText_NoResponse[];
+
+extern u8 gUnknown_083D61F0[];
+
+extern u16 gScriptItemId;
+
+bool8 ItemfinderCheckForHiddenItems(struct MapEvents *events, int);
+
+void sub_80C8FAC(u8 taskId)
+{
+    u8 taskData;
+
+    if(gScriptItemId == 0xAF)
+        taskData = gTasks[taskId].data[15] - 1;
+    else
+        taskData = ItemId_GetType(gScriptItemId) - 1;
+
+    gTasks[taskId].data[8] = (u32)gUnknown_083D61E4[taskData] >> 16;
+    gTasks[taskId].data[9] = (u32)gUnknown_083D61E4[taskData];
+    gTasks[taskId].func = sub_80A5B00;
+}
+
+void unknown_ItemMenu_Confirm(u8 var)
+{
+	sub_80C8FAC(var);
+	BeginNormalPaletteFade(0xFFFFFFFF, 0, 0, 16, 0);
+}
+
+void sub_80C9038(u8 var)
+{
+	sub_80C8FAC(var);
+	fade_screen(1, 0);
+}
+
+void SetUpItemUseOnFieldCallback(u8 taskId)
+{
+	if(gTasks[taskId].data[2] != 1)
+	{
+		gUnknown_0300485C = (void *)sub_80A5CC4;
+		unknown_ItemMenu_Confirm(taskId);
+	}
+	else
+		gUnknown_03005D00(taskId);
+}
+
+void sub_80C9098(u8 var1, u8 var2, const u8 *var3)
+{
+	StringExpandPlaceholders(gStringVar4, var3);
+	
+	if(!var2)
+	{
+		MenuZeroFillWindowRect(0, 13, 13, 20);
+		DisplayItemMessageOnField(var1, gStringVar4, sub_80A5C48, 1);
+	}
+	else
+		DisplayItemMessageOnField(var1, gStringVar4, sub_80A5C9C, 0);
+}
+
+void DisplayDadsAdviceCannotUseItemMessage(u8 var1, u8 var2)
+{
+	sub_80C9098(var1, var2, gOtherText_DadsAdvice);
+}
+
+void sub_80C9104(u8 var1, u8 var2)
+{
+	sub_80C9098(var1, var2, gOtherText_CantGetOffBike);
+}
+
+u8 CheckIfItemIsTMHMOrEvolutionStone(u16 itemId)
+{
+	if(ItemId_GetFieldFunc(itemId) == ItemUseOutOfBattle_TMHM)
+		return 1;
+	else if(ItemId_GetFieldFunc(itemId) == ItemUseOutOfBattle_EvolutionStone)
+		return 2;
+	else
+		return 0;
+}
+
+void sub_80C9154(u8 taskId)
+{
+	struct MailStruct mailStruct;
+
+	if(!gPaletteFade.active)
+	{
+		mailStruct.var20 = gScriptItemId;
+		sub_80F890C(&mailStruct, sub_80A5D04, 0);
+		DestroyTask(taskId);
+	}
+}
+
+void ItemUseOutOfBattle_Mail(u8 taskId)
+{
+	BeginNormalPaletteFade(0xFFFFFFFF, 0, 0, 16, 0);
+	gTasks[taskId].func = sub_80C9154;
+}
+
+void ItemUseOutOfBattle_Bike(u8 taskId)
+{
+	s16 x, y;
+	u8 tileBehavior;
+	
+	PlayerGetDestCoords(&x, &y);
+	tileBehavior = MapGridGetMetatileBehaviorAt(x, y);
+	
+	if(FlagGet(0x82B) == TRUE
+		|| MetatileBehavior_IsVerticalRail(tileBehavior) == TRUE
+		|| MetatileBehavior_IsHorizontalRail(tileBehavior) == TRUE
+		|| MetatileBehavior_IsIsolatedVerticalRail(tileBehavior) == TRUE
+		|| MetatileBehavior_IsIsolatedHorizontalRail(tileBehavior) == TRUE)
+	{
+		sub_80C9104(taskId, gTasks[taskId].data[2]);
+	}
+	else
+	{
+		if(sub_8053C44() == TRUE && sub_80E5EF4() == FALSE)
+		{
+			gUnknown_03005D00 = (void *)ItemUseOnFieldCB_Bike;
+			SetUpItemUseOnFieldCallback(taskId);
+		}
+		else
+			DisplayDadsAdviceCannotUseItemMessage(taskId, gTasks[taskId].data[2]);
+	}
+}
+
+void ItemUseOnFieldCB_Bike(u8 taskId)
+{
+	if(ItemId_GetSecondaryId(gScriptItemId) == 0)
+		GetOnOffBike(2);
+	if(ItemId_GetSecondaryId(gScriptItemId) == 1)
+		GetOnOffBike(4);
+	
+	sub_8064E2C();
+	ScriptContext2_Disable();
+	DestroyTask(taskId);
+}
+
+bool32 CanFish(void)
+{
+    s16 x, y;
+    u16 tileBehavior;
+
+    GetXYCoordsOneStepInFrontOfPlayer(&x, &y);
+    tileBehavior = MapGridGetMetatileBehaviorAt(x, y);
+
+    if (MetatileBehavior_IsWaterfall(tileBehavior))
+        return FALSE;
+
+    if (TestPlayerAvatarFlags(PLAYER_AVATAR_FLAG_4))
+        return FALSE;
+
+    if (!TestPlayerAvatarFlags(PLAYER_AVATAR_FLAG_SURFING))
+    {
+        if (IsPlayerFacingSurfableFishableWater())
+            return TRUE;
+    }
+    else
+    {
+        if (MetatileBehavior_IsSurfableWaterOrUnderwater(tileBehavior) && !MapGridIsImpassableAt(x, y))
+            return TRUE;
+        if (MetatileBehavior_IsBridge(tileBehavior) == TRUE)
+            return TRUE;
+    }
+
+    return FALSE;
+}
+
+void ItemUseOutOfBattle_Rod(u8 taskId)
+{
+	if(CanFish() == TRUE)
+	{
+		gUnknown_03005D00 = (void *)ItemUseOnFieldCB_Rod;
+		SetUpItemUseOnFieldCallback(taskId);
+	}
+	else
+		DisplayDadsAdviceCannotUseItemMessage(taskId, gTasks[taskId].data[2]);
+}
+
+void ItemUseOnFieldCB_Rod(u8 taskId)
+{
+	StartFishing(ItemId_GetSecondaryId(gScriptItemId));
+	DestroyTask(taskId);
+}
+
+void ItemUseOutOfBattle_Itemfinder(u8 var)
+{
+	sav12_xor_increment(0x27);
+	gUnknown_03005D00 = (void *)ItemUseOnFieldCB_Itemfinder;
+	SetUpItemUseOnFieldCallback(var);
+}
+
+void ItemUseOnFieldCB_Itemfinder(u8 taskId)
+{
+    if(ItemfinderCheckForHiddenItems(gMapHeader.events, taskId) == TRUE)
+        gTasks[taskId].func = sub_80C9458;
+    else
+        DisplayItemMessageOnField(taskId, gOtherText_NoResponse, sub_80C9520, 0);
+}
+
+void sub_80C9458(u8 taskId)
+{
+    u8 var;
+    u8 playerDir;
+    u8 i;
+    s16 *data = gTasks[taskId].data;
+
+    if(!data[3])
+    {
+        if(data[4] == 4)
+        {
+            var = sub_80C9908(data[0], data[1]);
+            if(var)
+            {
+                sub_80C997C(gUnknown_083D61F0[var - 1]);
+                gTasks[taskId].func = sub_80C99EC;
+            }
+            else
+            {
+                playerDir = player_get_direction_lower_nybble();
+
+                for (i = 0; i < 4; i++)
+                    if (playerDir == gUnknown_083D61F0[i])
+                        data[5] = (i + 1) & 3;
+
+                gTasks[taskId].func = sub_80C9A38;
+                data[3] = 0;
+                data[2] = 0;
+            }
+			return;
+        }
+        PlaySE(0x48);
+        data[4]++;
+    }
+    data[3] = (data[3] + 1) & 0x1F;
+}
+
+void sub_80C9520(u8 taskId)
+{
+	MenuZeroFillWindowRect(0, 14, 29, 19);
+	sub_8064E2C();
+	ScriptContext2_Disable();
+	DestroyTask(taskId);
+}
+
+// too much struct math.
+__attribute__((naked))
+bool8 ItemfinderCheckForHiddenItems(struct MapEvents *events, int var)
+{
+	asm(".syntax unified\n\
+	push {r4-r7,lr}\n\
+	mov r7, r9\n\
+	mov r6, r8\n\
+	push {r6,r7}\n\
+	sub sp, 0x4\n\
+	adds r5, r0, 0\n\
+	lsls r1, 24\n\
+	lsrs r6, r1, 24\n\
+	mov r4, sp\n\
+	adds r4, 0x2\n\
+	mov r0, sp\n\
+	adds r1, r4, 0\n\
+	bl PlayerGetDestCoords\n\
+	ldr r1, _080C9618 @ =gTasks\n\
+	lsls r0, r6, 2\n\
+	adds r0, r6\n\
+	lsls r0, 3\n\
+	adds r0, r1\n\
+	movs r1, 0\n\
+	strh r1, [r0, 0xC]\n\
+	movs r3, 0\n\
+	mov r9, r4\n\
+	ldrb r0, [r5, 0x3]\n\
+	cmp r3, r0\n\
+	bge _080C95FC\n\
+	subs r1, 0x5\n\
+	mov r8, r1\n\
+_080C9580:\n\
+	lsls r3, 16\n\
+	asrs r1, r3, 16\n\
+	ldr r2, [r5, 0x10]\n\
+	lsls r0, r1, 1\n\
+	adds r0, r1\n\
+	lsls r4, r0, 2\n\
+	adds r1, r4, r2\n\
+	ldrb r0, [r1, 0x5]\n\
+	adds r7, r3, 0\n\
+	cmp r0, 0x7\n\
+	bne _080C95EC\n\
+	movs r2, 0x96\n\
+	lsls r2, 2\n\
+	adds r0, r2, 0\n\
+	ldrh r1, [r1, 0xA]\n\
+	adds r0, r1\n\
+	lsls r0, 16\n\
+	lsrs r0, 16\n\
+	bl FlagGet\n\
+	lsls r0, 24\n\
+	cmp r0, 0\n\
+	bne _080C95EC\n\
+	ldr r1, [r5, 0x10]\n\
+	adds r1, r4, r1\n\
+	ldrh r2, [r1]\n\
+	adds r2, 0x7\n\
+	mov r0, sp\n\
+	ldrh r0, [r0]\n\
+	subs r2, r0\n\
+	ldrh r0, [r1, 0x2]\n\
+	adds r0, 0x7\n\
+	mov r3, r9\n\
+	ldrh r1, [r3]\n\
+	subs r0, r1\n\
+	lsls r0, 16\n\
+	lsrs r0, 16\n\
+	lsls r2, 16\n\
+	asrs r1, r2, 16\n\
+	movs r3, 0xE0\n\
+	lsls r3, 11\n\
+	adds r2, r3\n\
+	lsrs r2, 16\n\
+	cmp r2, 0xE\n\
+	bhi _080C95EC\n\
+	lsls r0, 16\n\
+	asrs r2, r0, 16\n\
+	cmp r2, r8\n\
+	blt _080C95EC\n\
+	cmp r2, 0x5\n\
+	bgt _080C95EC\n\
+	adds r0, r6, 0\n\
+	bl sub_80C9838\n\
+_080C95EC:\n\
+	movs r1, 0x80\n\
+	lsls r1, 9\n\
+	adds r0, r7, r1\n\
+	lsrs r3, r0, 16\n\
+	asrs r0, 16\n\
+	ldrb r2, [r5, 0x3]\n\
+	cmp r0, r2\n\
+	blt _080C9580\n\
+_080C95FC:\n\
+	adds r0, r6, 0\n\
+	bl sub_80C9720\n\
+	ldr r0, _080C9618 @ =gTasks\n\
+	lsls r1, r6, 2\n\
+	adds r1, r6\n\
+	lsls r1, 3\n\
+	adds r1, r0\n\
+	movs r3, 0xC\n\
+	ldrsh r0, [r1, r3]\n\
+	cmp r0, 0x1\n\
+	beq _080C961C\n\
+	movs r0, 0\n\
+	b _080C961E\n\
+	.align 2, 0\n\
+_080C9618: .4byte gTasks\n\
+_080C961C:\n\
+	movs r0, 0x1\n\
+_080C961E:\n\
+	add sp, 0x4\n\
+	pop {r3,r4}\n\
+	mov r8, r3\n\
+	mov r9, r4\n\
+	pop {r4-r7}\n\
+	pop {r1}\n\
+	bx r1\n\
+	.syntax divided");
+}