pokecrystal-board/macros/code.asm
2018-01-16 17:27:50 -05:00

55 lines
762 B
NASM

; Syntactic sugar macros
lb: MACRO ; r, hi, lo
ld \1, (\2 & $ff) << 8 + (\3 & $ff)
ENDM
ln: MACRO ; r, hi, lo
ld \1, (\2 & $f) << 4 + (\3 & $f)
ENDM
ldpixel: MACRO
if _NARG >= 5
lb \1, \2 * 8 + \4, \3 * 8 + \5
else
lb \1, \2 * 8, \3 * 8
endc
ENDM
depixel EQUS "ldpixel de,"
bcpixel EQUS "ldpixel bc,"
; Design patterns
jumptable: MACRO
ld a, [\2]
ld e, a
ld d, 0
ld hl, \1
add hl, de
add hl, de
ld a, [hli]
ld h, [hl]
ld l, a
jp hl
ENDM
maskbits: MACRO
; masks just enough bits to cover the argument
; e.g. "maskbits 26" becomes "and %00011111" (since 26 - 1 = %00011001)
; example usage in rejection sampling:
; .loop
; call Random
; maskbits 30
; cp 30
; jr nc, .loop
x = 1
rept 8
if x + 1 < (\1)
x = x << 1 | 1
endc
endr
and x
ENDM