Files
pokecrystal/engine/routines/math.asm
mid-kid baa0dc5a96 Organize the engine/ directory
This is an informed attempt at reorganizing the engine/ directory by
creating categorized subdirectories, in order to make it easier to
navigate and find things.

The directories created are as follows:
* engine/game: Contains all "minigames", things like the unown puzzle
and slot machine.
* engine/gfx: Contains all handling of graphics. From loading palettes
to playing animations.
* engine/link: Contains all multiplayer functionality.
* engine/menu: Contains all generic/misc. menus and menu code.
Other, more specialized menus are in their own subdirectories (pokedex,
pokegear, party menu, etc).
* engine/overworld: Contains all handling of the overworld. From loading
and connecting maps to wild encounters and the scripting engine.
* engine/pokegear: In the same vein as engine/pokedex, except it could
use some more splitting up.
* engine/pokemon: Contains everything related to manipulating pokemon
data. From the pokemon storage system to evolution and mail.
* engine/printer: Contains everything related to printing things as well
as the printer communication.
* engine/title: Contains intro sequences, title screens and credits.
2018-03-13 13:21:40 +01:00

197 lines
2.4 KiB
NASM
Executable File

_Multiply:: ; 66de
; hMultiplier is one byte.
ld a, 8
ld b, a
xor a
ld [hProduct], a
ld [hMathBuffer + 1], a
ld [hMathBuffer + 2], a
ld [hMathBuffer + 3], a
ld [hMathBuffer + 4], a
.loop
ld a, [hMultiplier]
srl a
ld [hMultiplier], a
jr nc, .next
ld a, [hMathBuffer + 4]
ld c, a
ld a, [hMultiplicand + 2]
add c
ld [hMathBuffer + 4], a
ld a, [hMathBuffer + 3]
ld c, a
ld a, [hMultiplicand + 1]
adc c
ld [hMathBuffer + 3], a
ld a, [hMathBuffer + 2]
ld c, a
ld a, [hMultiplicand + 0]
adc c
ld [hMathBuffer + 2], a
ld a, [hMathBuffer + 1]
ld c, a
ld a, [hProduct]
adc c
ld [hMathBuffer + 1], a
.next
dec b
jr z, .done
; hMultiplicand <<= 1
ld a, [hMultiplicand + 2]
add a
ld [hMultiplicand + 2], a
ld a, [hMultiplicand + 1]
rla
ld [hMultiplicand + 1], a
ld a, [hMultiplicand + 0]
rla
ld [hMultiplicand + 0], a
ld a, [hProduct]
rla
ld [hProduct], a
jr .loop
.done
ld a, [hMathBuffer + 4]
ld [hProduct + 3], a
ld a, [hMathBuffer + 3]
ld [hProduct + 2], a
ld a, [hMathBuffer + 2]
ld [hProduct + 1], a
ld a, [hMathBuffer + 1]
ld [hProduct + 0], a
ret
; 673e
_Divide:: ; 673e
xor a
ld [hMathBuffer + 0], a
ld [hMathBuffer + 1], a
ld [hMathBuffer + 2], a
ld [hMathBuffer + 3], a
ld [hMathBuffer + 4], a
ld a, 9
ld e, a
.loop
ld a, [hMathBuffer + 0]
ld c, a
ld a, [hDividend + 1]
sub c
ld d, a
ld a, [hDivisor]
ld c, a
ld a, [hDividend + 0]
sbc c
jr c, .next
ld [hDividend + 0], a
ld a, d
ld [hDividend + 1], a
ld a, [hMathBuffer + 4]
inc a
ld [hMathBuffer + 4], a
jr .loop
.next
ld a, b
cp 1
jr z, .done
ld a, [hMathBuffer + 4]
add a
ld [hMathBuffer + 4], a
ld a, [hMathBuffer + 3]
rla
ld [hMathBuffer + 3], a
ld a, [hMathBuffer + 2]
rla
ld [hMathBuffer + 2], a
ld a, [hMathBuffer + 1]
rla
ld [hMathBuffer + 1], a
dec e
jr nz, .next2
ld e, 8
ld a, [hMathBuffer + 0]
ld [hDivisor], a
xor a
ld [hMathBuffer + 0], a
ld a, [hDividend + 1]
ld [hDividend + 0], a
ld a, [hDividend + 2]
ld [hDividend + 1], a
ld a, [hDividend + 3]
ld [hDividend + 2], a
.next2
ld a, e
cp 1
jr nz, .okay
dec b
.okay
ld a, [hDivisor]
srl a
ld [hDivisor], a
ld a, [hMathBuffer + 0]
rr a
ld [hMathBuffer + 0], a
jr .loop
.done
ld a, [hDividend + 1]
ld [hDivisor], a
ld a, [hMathBuffer + 4]
ld [hDividend + 3], a
ld a, [hMathBuffer + 3]
ld [hDividend + 2], a
ld a, [hMathBuffer + 2]
ld [hDividend + 1], a
ld a, [hMathBuffer + 1]
ld [hDividend + 0], a
ret
; 67c1