Merge pull request #4 from pret/master

Merge master

2 files changed, 727 insertions, 0 deletions

diff --git a/engine/battle/core.asm b/engine/battle/core.asm
new file mode 100644
index 0000000..c79fb22
--- /dev/null
+++ b/engine/battle/core.asm
@@ -0,0 +1,69 @@
+include "constants.asm"
+
+SECTION "Battle Random", ROMX [$63DA], BANK [$0F]
+_BattleRandom: ; 3e3da (f:63da)
+; If the normal RNG is used in a link battle it'll desync.
+; To circumvent this a shared PRNG is used instead.
+
+; But if we're in a non-link battle we're safe to use it
+	ld a, [wLinkMode]
+	and a
+	jp z, Random
+
+; The PRNG operates in streams of 10 values.
+
+; Which value are we trying to pull?
+	push hl
+	push bc
+	ld a, [wLinkBattleRNCount]
+	ld c, a
+	ld b, $0
+	ld hl, wLinkBattleRNs
+	add hl, bc
+	inc a
+	ld [wLinkBattleRNCount], a
+
+; If we haven't hit the end yet, we're good
+	cp 9 ; number of seeds, including the last one. see comment in pokecrystal
+	ld a, [hl]
+	pop bc
+	pop hl
+	ret c
+
+; If we have, we have to generate new pseudorandom data
+; Instead of having multiple PRNGs, ten seeds are used
+	push hl
+	push bc
+	push af
+
+; Reset count to 0
+	xor a
+	ld [wLinkBattleRNCount], a
+	ld hl, wLinkBattleRNs
+	ld b, 9 ; number of seeds; in release, this was increased to 10
+
+; Generate next number in the sequence for each seed
+; a[n+1] = (a[n] * 5 + 1) % 256
+.loop
+	; get last #
+	ld a, [hl]
+
+	; a * 5 + 1
+	ld c, a
+	add a
+	add a
+	add c
+	inc a
+
+	; update #
+	ld [hli], a
+	dec b
+	jr nz, .loop
+
+; This has the side effect of pulling the last value first,
+; then wrapping around. As a result
+
+	pop af
+	pop bc
+	pop hl
+	ret
diff --git a/engine/items/inventory.asm b/engine/items/inventory.asm
new file mode 100755
index 0000000..4a95bac
--- /dev/null
+++ b/engine/items/inventory.asm
@@ -0,0 +1,658 @@
+INCLUDE "constants.asm"

+

+SECTION "AddItemToInventory_", ROMX[$4AA1], BANK[$03]

+

+_ReceiveItem: ; 03:4AA1

+	call DoesHLEqualwNumBagItems

+	jp nz, PutItemInPocket

+	push hl

+	ld hl, CheckItemPocket

+	ld a, BANK(CheckItemPocket)

+	call FarCall_hl

+	ld a, [wItemAttributeParamBuffer]

+	dec a

+	ld hl, .Pockets

+	jp CallJumptable

+	

+.Pockets: ; 03:4ABA

+	dw .Item

+	dw .KeyItem

+	dw .Ball

+	dw .TMHM

+

+.Item: ; 03:4AC2

+	pop hl

+	jp PutItemInPocket

+

+.KeyItem: ; 03:4AC6

+	pop hl

+	jp ReceiveKeyItem

+

+.Ball: ; 03:4ACA

+	pop hl

+	ld a, [wCurItem]

+	ld c, a

+	call GetBallIndex

+	jp ReceiveBall

+

+.TMHM: ; 03:4AD5

+	pop hl

+	ld a, [wCurItem]

+	ld c, a

+	call GetTMHMNumber

+	jp ReceiveTMHM

+	

+

+_TossItem: ; 03:4AE0

+	call DoesHLEqualwNumBagItems

+	jr nz, .remove_item

+	push hl

+	ld hl, CheckItemPocket

+	ld a, BANK(CheckItemPocket)

+	call FarCall_hl

+	ld a, [wItemAttributeParamBuffer]

+	dec a

+	ld hl, .Pockets

+	jp CallJumptable

+	

+.Pockets ; 03:4AF8

+	dw .Item

+	dw .KeyItem

+	dw .Ball

+	dw .TMHM

+	

+.Ball ; 03:4B00

+	pop hl

+	ld a, [wCurItem]

+	ld c, a

+	call GetBallIndex

+	jp TossBall

+	

+.TMHM ; 03:4B0B

+	pop hl

+	ld a, [wCurItem]

+	ld c, a

+	call GetTMHMNumber

+	jp TossTMHM

+	

+.KeyItem ; 03:4B16

+	pop hl

+	jp TossKeyItem

+	

+.Item ; 03:4B1A

+	pop hl

+

+.remove_item ; 03:4B1B

+	jp RemoveItemFromPocket

+

+

+_CheckItem: ; 03:4B1E

+	call DoesHLEqualwNumBagItems

+	jr nz, .not_bag

+	push hl

+	ld hl, CheckItemPocket

+	ld a, BANK(CheckItemPocket)

+	call FarCall_hl

+	ld a, [wItemAttributeParamBuffer]

+	dec a

+	ld hl, .Pockets

+	jp CallJumptable

+	

+.Pockets ; 03:4B36

+	dw .Item

+	dw .KeyItem

+	dw .Ball

+	dw .TMHM

+	

+.Ball ; 03:4B3E

+	pop hl

+	ld a, [wCurItem]

+	ld c, a

+	call GetBallIndex

+	jp CheckBall

+

+.TMHM ; 03:4B49

+	pop hl

+	ld a, [wCurItem]

+	ld c, a

+	call GetTMHMNumber

+	jp CheckTMHM

+	

+.KeyItem ; 03:4B54

+	pop hl

+	jp CheckKeyItems

+	

+.Item ; 03:4B58

+	pop hl

+	

+.not_bag

+	jp CheckTheItem

+

+

+DoesHLEqualwNumBagItems: ; 03:4B5C

+	ld a, l

+	cp LOW(wNumBagItems)

+	ret nz

+	ld a, h

+	cp HIGH(wNumBagItems)

+	ret

+

+

+PutItemInPocket: ; 03:4B64

+	ld d, h

+	ld e, l

+	inc hl

+	ld a, [wCurItem]

+	ld c, a

+	ld b, 0

+	

+; will add the item once the total

+; available space (b) exceeds the

+; amount being added

+.loop

+	ld a, [hli]

+	cp -1

+	jr z, .terminator

+	cp c

+	jr nz, .next

+	ld a, 99

+	sub [hl]

+	add b

+	ld b, a

+	ld a, [wItemQuantity]

+	cp b

+	jr z, .can_add

+	jr c, .can_add

+

+.next

+	inc hl

+	jr .loop

+	

+.terminator

+	call GetPocketCapacity

+	ld a, [de]

+	cp c

+	jr c, .can_add

+	

+	and a

+	ret

+	

+.can_add

+	ld h, d

+	ld l, e

+	ld a, [wCurItem]

+	ld c, a

+	

+.loop2

+	inc hl

+	ld a, [hli]

+	cp a, -1

+	jr z, .terminator2

+	cp c

+	jr nz, .loop2

+	

+	ld a, [wItemQuantity]

+	add [hl]

+	cp a, 100

+	jr nc, .set_max

+	ld [hl], a

+	jr .done

+

+; set this slot's quantity to 99,

+; and keep iterating through list

+; to add remaining amount

+.set_max

+	ld [hl], 99

+	sub 99

+	ld [wItemQuantity], a

+	jr .loop2

+	

+.terminator2

+	dec hl

+	ld a, [wCurItem]

+	ld [hli], a

+	ld a, [wItemQuantity]

+	ld [hli], a

+	ld [hl], -1

+	ld h, d

+	ld l, e

+	inc [hl]

+	

+.done

+	scf

+	ret

+

+	

+GetPocketCapacity: ; 03:4BC1

+	ld c, MAX_ITEMS

+	ld a, e

+	cp a, LOW(wNumBagItems)

+	jr nz, .not_bag

+	ld a, d

+	cp HIGH(wNumBagItems)

+	ret z

+	

+.not_bag

+	ld c, MAX_PC_ITEMS

+	ret

+

+	

+RemoveItemFromPocket: ;03:4BCF

+	ld d, h

+	ld e, l

+	inc hl

+	ld a, [wItemIndex]

+	ld c, a

+	ld b, 0

+	add hl, bc

+	add hl, bc

+	inc hl

+	ld a, [wItemQuantity]

+	ld b, a

+	ld a, [hl]

+	sub b

+	jr c, .underflow

+	

+	ld [hl], a

+	ld [wItemQuantityBuffer], a

+	and a

+	jr nz, .done

+	

+; if the remaining quantity is zero

+; then erase the slot by shifting

+; the subsequent data upwards

+	dec hl

+	ld b, h

+	ld c, l

+	inc hl

+	inc hl

+	

+.loop

+	ld a, [hli]

+	ld [bc], a

+	inc bc

+	cp -1

+	jr nz, .loop

+	ld h, d

+	ld l, e

+	dec [hl]

+	

+.done

+	scf

+	ret

+	

+.underflow

+	and a

+	ret

+	

+	

+CheckTheItem: ; 03:4BFD

+	ld a, [wCurItem]

+	ld c, a

+	

+.loop

+	inc hl

+	ld a, [hli]

+	cp -1

+	jr z, .fail

+	cp c

+	jr nz, .loop

+	

+	scf

+	ret

+	

+.fail

+	and a

+	ret

+

+	

+ReceiveKeyItem: ; 03:4C0E

+	ld hl, wNumKeyItems

+	ld a, [hli]

+	cp a, MAX_KEY_ITEMS

+	jr nc, .full_pack

+	ld c, a

+	ld b, 0

+	add hl, bc

+	ld a, [wCurItem]

+	ld [hli], a

+	ld [hl], -1

+	ld hl, wNumKeyItems

+	inc [hl]

+	scf

+	ret

+	

+.full_pack

+	and a

+	ret

+	

+	

+TossKeyItem: ; 03:4C28

+	ld hl, wNumKeyItems

+	dec [hl]

+	inc hl

+	ld a, [wItemIndex]

+	ld e, a

+	ld d, 0

+	add hl, de

+	ld d, h

+	ld e, l

+	inc hl

+	

+; erase this item by shifting

+; all subsequent data upwards

+.loop

+	ld a, [hli]

+	ld [de], a

+	inc de

+	cp -1

+	jr nz, .loop

+	scf

+	ret

+	

+	

+CheckKeyItems: ; 03:4C40

+	ld a, [wCurItem]

+	ld c, a

+	ld hl, wKeyItems

+	

+.loop

+	ld a, [hli]

+	cp c

+	jr z, .done

+	cp -1

+	jr nz, .loop

+

+	and a

+	ret

+	

+.done

+	scf

+	ret

+	

+	

+; get index of ball item id c from BallItems

+GetBallIndex: ; 03:4C53

+	ld a, c

+	push hl

+	push de

+	push bc

+	ld hl, BallItems

+	ld de, 1

+	call FindItemInTable

+	ld a, b

+	pop bc

+	pop de

+	pop hl

+	ld c, a

+	ret

+	

+	

+; get ball item id at index c in BallItems

+GetBallByIndex: ; 03:4c66

+	push bc

+	push hl

+	ld b, 0

+	ld hl, BallItems

+	add hl, bc

+	ld a, [hl]

+	pop hl

+	pop bc

+	ld c, a

+	ret

+	

+	

+BallItems: ; 03:4C73

+	db ITEM_MASTER_BALL

+	db ITEM_ULTRA_BALL

+	db ITEM_GREAT_BALL

+	db ITEM_POKE_BALL

+	db -1

+

+

+; empties the ball pocket by setting the

+; terminator immediately after wNumBallItems

+

+	; Note, the ball pocket appears to be

+	; a fixed length, not -1 terminated

+EmptyBallPocket: ; 03:4C78

+	ld hl, wNumBallItems

+	xor a

+	ld [hli], a

+	ld [hl], -1

+	ret

+	

+

+ReceiveBall: ; 03:4C80

+	ld hl, wBallQuantities

+	ld b, 0

+	add hl, bc

+	ld a, [wItemQuantity]

+	add [hl]

+	cp 100

+	jr nc, .overflow

+	ld b, a

+	ld a, [hl]

+	and a

+	jr nz, .done

+	

+; increase the ball pocket size if

+; this ball's previous quantity was 0

+	ld a, [wNumBallItems]

+	inc a

+	ld [wNumBallItems], a

+	

+.done

+	ld [hl], b

+	scf

+	ret

+	

+.overflow

+	and a

+	ret

+	

+

+TossBall: ; 03:4C9F

+	ld hl, wBallQuantities

+	ld b, 0

+	add hl, bc

+	ld a, [wItemQuantity]

+	ld b, a

+	ld a, [hl]

+	sub b

+	jr c, .underflow

+	jr nz, .done

+	

+; increase the ball pocket size if

+; this ball's new quantity is 0

+	ld b, a

+	ld a, [wNumBallItems]

+	dec a

+	ld [wNumBallItems], a

+	ld a, b

+	

+.done

+	ld [hl], a

+	ld [wItemQuantityBuffer], a

+	scf

+	ret

+	

+.underflow

+	and a

+	ret

+	

+	

+CheckBall: ; 03:4CC0

+	ld hl, wBallQuantities

+	ld b, 0

+	add hl, bc

+	ld a, [hl]

+	and a

+	ret z

+	scf

+	ret

+

+	

+ReceiveTMHM: ; 03:4CCB

+	ld b, 0

+	ld hl, wTMsHMs

+	add hl, bc

+	ld a, [wItemQuantity]

+	add [hl]

+	cp 100

+	jr nc, .overflow

+	ld [hl], a

+	scf

+	ret

+	

+.overflow

+	and a

+	ret

+	

+	

+TossTMHM: ; 03:4CDE

+	ld b, 0

+	ld hl, wTMsHMs

+	add hl, bc

+	ld a, [wItemQuantity]

+	ld b, a

+	ld a, [hl]

+	sub b

+	jr c, .underflow

+	

+	ld [hl], a

+	ld [wItemQuantityBuffer], a

+	scf

+	ret

+

+.underflow

+	and a

+	ret

+

+	

+CheckTMHM: ; 03:4CF4

+	ld b, 0

+	ld hl, wTMsHMs

+	add hl, bc

+	ld a, [hl]

+	and a

+	ret z

+	scf

+	ret

+

+GetTMHMNumber: ; 03:4CFF

+	ld a, c

+	ld c, 0

+	

+	sub ITEM_TM01

+	jr c, .not_machine

+	

+	cp ITEM_C8 - ITEM_TM01

+	jr z, .not_machine

+	jr c, .finish

+	

+	inc c

+	cp ITEM_E1 - ITEM_TM01

+	jr z, .not_machine

+	

+	jr c, .finish

+	inc c

+

+; c represents the amount of non-TMs which

+; appear ahead of this item in the list

+; so subtract that value before exiting

+.finish

+	sub c

+	ld c, a

+	scf

+	ret

+	

+.not_machine

+	and a

+	ret

+	

+SECTION "_CheckTossableItem", ROMX[$53AD], BANK[$03]

+

+; Return 1 in wItemAttributeParamBuffer and carry if wCurItem can't be removed from the bag.

+_CheckTossableItem: ; 03:53AD

+	ld a, ITEMATTR_PERMISSIONS

+	call GetItemAttr

+	bit CANT_TOSS_F, a

+	jr nz, ItemAttr_ReturnCarry

+	and a

+	ret

+

+; Return 1 in wItemAttributeParamBuffer and carry if wCurItem can't be selected.

+CheckSelectableItem: ; 03:53B8

+	ld a, ITEMATTR_PERMISSIONS

+	call GetItemAttr

+	bit CANT_SELECT_F, a

+	jr nz, ItemAttr_ReturnCarry

+	and a

+	ret

+

+; Return the pocket for wCurItem in wItemAttributeParamBuffer.

+CheckItemPocket: ; 03:53C3

+	ld a, ITEMATTR_POCKET

+	call GetItemAttr

+	and $f

+	ld [wItemAttributeParamBuffer], a

+	ret

+

+; Return the context for wCurItem in wItemAttributeParamBuffer.

+CheckItemContext: ; 03:53CE

+	ld a, ITEMATTR_HELP

+	call GetItemAttr

+	and $f

+	ld [wItemAttributeParamBuffer], a

+	ret

+

+; Return the menu for wCurItem in wItemAttributeParamBuffer.

+CheckItemMenu: ; 03:53D9

+	ld a, ITEMATTR_HELP

+	call GetItemAttr

+	swap a

+	and $f

+	ld [wItemAttributeParamBuffer], a

+	ret

+	

+; Get attribute a of wCurItem.

+GetItemAttr: ; 03:53E6

+	push hl

+	push bc

+	ld hl, ItemAttributes

+	ld c, a

+	ld b, 0

+	add hl, bc

+	xor a

+	ld [wItemAttributeParamBuffer], a

+	ld a, [wCurItem]

+	dec a

+	ld c, a

+	ld a, ITEMATTR_STRUCT_LENGTH

+	call AddNTimes

+	ld a, BANK(ItemAttributes)

+	call GetFarByte

+	pop bc

+	pop hl

+	ret

+

+ItemAttr_ReturnCarry: ; 03:5405

+	ld a, 1

+	ld [wItemAttributeParamBuffer], a

+	scf

+	ret

+	

+; Return the price of wCurItem in de.

+GetItemPrice: ; 03:540C

+	push hl

+	push bc

+	ld a, ITEMATTR_PRICE

+	call GetItemAttr

+	ld e, a

+	ld a, ITEMATTR_PRICE_HI

+	call GetItemAttr

+	ld d, a

+	pop bc

+	pop hl

+	ret