pokecrystal-board/engine/experience.asm

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NASM
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CalcLevel: ; 50e1b
ld a, [TempMonSpecies]
ld [CurSpecies], a
call GetBaseData
ld d, 1
.next_level
inc d
ld a, d
cp (MAX_LEVEL + 1) % $100
jr z, .got_level
call CalcExpAtLevel
push hl
ld hl, TempMonExp + 2
ld a, [hProduct + 3]
ld c, a
ld a, [hld]
sub c
ld a, [hProduct + 2]
ld c, a
ld a, [hld]
sbc c
ld a, [hProduct + 1]
ld c, a
ld a, [hl]
sbc c
pop hl
jr nc, .next_level
.got_level
dec d
ret
CalcExpAtLevel: ; 50e47
; (a/b)*n**3 + c*n**2 + d*n - e
ld a, [BaseGrowthRate]
add a
add a
ld c, a
ld b, 0
ld hl, GrowthRates
add hl, bc
; Cube the level
call .LevelSquared
ld a, d
ld [hMultiplier], a
call Multiply
; Multiply by a
ld a, [hl]
and $f0
swap a
ld [hMultiplier], a
call Multiply
; Divide by b
ld a, [hli]
and $f
ld [hDivisor], a
ld b, 4
call Divide
; Push the cubic term to the stack
ld a, [hQuotient + 0]
push af
ld a, [hQuotient + 1]
push af
ld a, [hQuotient + 2]
push af
; Square the level and multiply by the lower 7 bits of c
call .LevelSquared
ld a, [hl]
and $7f
ld [hMultiplier], a
call Multiply
; Push the absolute value of the quadratic term to the stack
ld a, [hProduct + 1]
push af
ld a, [hProduct + 2]
push af
ld a, [hProduct + 3]
push af
ld a, [hli]
push af
; Multiply the level by d
xor a
ld [hMultiplicand + 0], a
ld [hMultiplicand + 1], a
ld a, d
ld [hMultiplicand + 2], a
ld a, [hli]
ld [hMultiplier], a
call Multiply
; Subtract e
ld b, [hl]
ld a, [hProduct + 3]
sub b
ld [hMultiplicand + 2], a
ld b, $0
ld a, [hProduct + 2]
sbc b
ld [hMultiplicand + 1], a
ld a, [hProduct + 1]
sbc b
ld [hMultiplicand], a
; If bit 7 of c is set, c is negative; otherwise, it's positive
pop af
and $80
jr nz, .subtract
; Add c*n**2 to (d*n - e)
pop bc
ld a, [hProduct + 3]
add b
ld [hMultiplicand + 2], a
pop bc
ld a, [hProduct + 2]
adc b
ld [hMultiplicand + 1], a
pop bc
ld a, [hProduct + 1]
adc b
ld [hMultiplicand], a
jr .done_quadratic
.subtract
; Subtract c*n**2 from (d*n - e)
pop bc
ld a, [hProduct + 3]
sub b
ld [hMultiplicand + 2], a
pop bc
ld a, [hProduct + 2]
sbc b
ld [hMultiplicand + 1], a
pop bc
ld a, [hProduct + 1]
sbc b
ld [hMultiplicand], a
.done_quadratic
; Add (a/b)*n**3 to (d*n - e +/- c*n**2)
pop bc
ld a, [hProduct + 3]
add b
ld [hMultiplicand + 2], a
pop bc
ld a, [hProduct + 2]
adc b
ld [hMultiplicand + 1], a
pop bc
ld a, [hProduct + 1]
adc b
ld [hMultiplicand], a
ret
.LevelSquared: ; 50eed
xor a
ld [hMultiplicand + 0], a
ld [hMultiplicand + 1], a
ld a, d
ld [hMultiplicand + 2], a
ld [hMultiplier], a
jp Multiply
INCLUDE "data/growth_rates.asm"