diff options
Diffstat (limited to 'engine/items/inventory.asm')
| -rw-r--r-- | engine/items/inventory.asm | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/engine/items/inventory.asm b/engine/items/inventory.asm new file mode 100644 index 00000000..1294ed8d --- /dev/null +++ b/engine/items/inventory.asm @@ -0,0 +1,150 @@ +; function to add an item (in varying quantities) to the player's bag or PC box +; INPUT: +; hl = address of inventory (either wNumBagItems or wNumBoxItems) +; [wcf91] = item ID +; [wItemQuantity] = item quantity +; sets carry flag if successful, unsets carry flag if unsuccessful +AddItemToInventory_: + ld a,[wItemQuantity] ; a = item quantity + push af + push bc + push de + push hl + push hl + ld d,PC_ITEM_CAPACITY ; how many items the PC can hold + ld a,wNumBagItems & $FF + cp l + jr nz,.checkIfInventoryFull + ld a,wNumBagItems >> 8 + cp h + jr nz,.checkIfInventoryFull +; if the destination is the bag + ld d,BAG_ITEM_CAPACITY ; how many items the bag can hold +.checkIfInventoryFull + ld a,[hl] + sub d + ld d,a + ld a,[hli] + and a + jr z,.addNewItem +.loop + ld a,[hli] + ld b,a ; b = ID of current item in table + ld a,[wcf91] ; a = ID of item being added + cp b ; does the current item in the table match the item being added? + jp z,.increaseItemQuantity ; if so, increase the item's quantity + inc hl + ld a,[hl] + cp a,$ff ; is it the end of the table? + jr nz,.loop +.addNewItem ; add an item not yet in the inventory + pop hl + ld a,d + and a ; is there room for a new item slot? + jr z,.done +; if there is room + inc [hl] ; increment the number of items in the inventory + ld a,[hl] ; the number of items will be the index of the new item + add a + dec a + ld c,a + ld b,0 + add hl,bc ; hl = address to store the item + ld a,[wcf91] + ld [hli],a ; store item ID + ld a,[wItemQuantity] + ld [hli],a ; store item quantity + ld [hl],$ff ; store terminator + jp .success +.increaseItemQuantity ; increase the quantity of an item already in the inventory + ld a,[wItemQuantity] + ld b,a ; b = quantity to add + ld a,[hl] ; a = existing item quantity + add b ; a = new item quantity + cp a,100 + jp c,.storeNewQuantity ; if the new quantity is less than 100, store it +; if the new quantity is greater than or equal to 100, +; try to max out the current slot and add the rest in a new slot + sub a,99 + ld [wItemQuantity],a ; a = amount left over (to put in the new slot) + ld a,d + and a ; is there room for a new item slot? + jr z,.increaseItemQuantityFailed +; if so, store 99 in the current slot and store the rest in a new slot + ld a,99 + ld [hli],a + jp .loop +.increaseItemQuantityFailed + pop hl + and a + jr .done +.storeNewQuantity + ld [hl],a + pop hl +.success + scf +.done + pop hl + pop de + pop bc + pop bc + ld a,b + ld [wItemQuantity],a ; restore the initial value from when the function was called + ret + +; function to remove an item (in varying quantities) from the player's bag or PC box +; INPUT: +; hl = address of inventory (either wNumBagItems or wNumBoxItems) +; [wWhichPokemon] = index (within the inventory) of the item to remove +; [wItemQuantity] = quantity to remove +RemoveItemFromInventory_: + push hl + inc hl + ld a,[wWhichPokemon] ; index (within the inventory) of the item being removed + sla a + add l + ld l,a + jr nc,.noCarry + inc h +.noCarry + inc hl + ld a,[wItemQuantity] ; quantity being removed + ld e,a + ld a,[hl] ; a = current quantity + sub e + ld [hld],a ; store new quantity + ld [wMaxItemQuantity],a + and a + jr nz,.skipMovingUpSlots +; if the remaining quantity is 0, +; remove the emptied item slot and move up all the following item slots +.moveSlotsUp + ld e,l + ld d,h + inc de + inc de ; de = address of the slot following the emptied one +.loop ; loop to move up the following slots + ld a,[de] + inc de + ld [hli],a + cp a,$ff + jr nz,.loop +; update menu info + xor a + ld [wListScrollOffset],a + ld [wCurrentMenuItem],a + ld [wBagSavedMenuItem],a + ld [wSavedListScrollOffset],a + pop hl + ld a,[hl] ; a = number of items in inventory + dec a ; decrement the number of items + ld [hl],a ; store new number of items + ld [wListCount],a + cp a,2 + jr c,.done + ld [wMaxMenuItem],a + jr .done +.skipMovingUpSlots + pop hl +.done + ret |