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-rwxr-xr-xengine/items/item_effects.asm79
1 files changed, 79 insertions, 0 deletions
diff --git a/engine/items/item_effects.asm b/engine/items/item_effects.asm
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+INCLUDE "constants.asm"
+
+SECTION "ApplyPPUp", ROMX[$78f6], BANK[$03]
+
+ApplyPPUp: ; 03:78f6
+ ld a, MON_MOVES
+ call GetPartyParamLocation
+ push hl
+ ld de, wStringBuffer1
+ predef FillPP
+ pop hl
+ ld c, MON_PP - MON_MOVES
+ ld b, 0
+ add hl, bc
+ ld de, wStringBuffer1 + 1
+ ld b, 0
+.loop
+ inc b
+ ld a, b
+ cp NUM_MOVES + 1
+ ret z
+ ld a, [wce37]
+ dec a
+ jr nz, .use
+ ld a, [wMenuCursorY]
+ inc a
+ cp b
+ jr nz, .skip
+.use
+ ld a, [hl]
+ and PP_UP_MASK
+ call nz, ComputeMaxPP
+.skip
+ inc hl
+ inc de
+ jr .loop
+
+ComputeMaxPP: ; 03:792B
+ push bc
+ ; Divide the base PP by 5.
+ ld a, [de]
+ ldh [hDividend + 3], a
+ xor a
+ ldh [hDividend], a
+ ldh [hDividend + 1], a
+ ldh [hDividend + 2], a
+ ld a, 5
+ ldh [hDivisor], a
+ ld b, 4
+ call Divide
+ ; Get the number of PP, which are bits 6 and 7 of the PP value stored in RAM.
+ ld a, [hl]
+ ld b, a
+ swap a
+ and $f
+ srl a
+ srl a
+ ld c, a
+.loop
+ ; Normally, a move with 40 PP would have 64 PP with three PP Ups.
+ ; Since this would overflow into bit 6, we prevent that from happening
+ ; by decreasing the extra amount of PP each PP Up provides, resulting
+ ; in a maximum of 61.
+ ldh a, [hQuotient + 2]
+ cp $8
+ jr c, .okay
+ ld a, $7
+.okay
+ add b
+ ld b, a
+ ld a, [wce37]
+ dec a
+ jr z, .no_pp_up
+ dec c
+ jr nz, .loop
+.no_pp_up
+ ld [hl], b
+ pop bc
+ ret \ No newline at end of file