05-30-2012, 10:15 PM
Update (cleaned up):
I think this one is clearer.
Both this 2 routines do the same. :?: The one on the right seems optimized (It's used in ZX Basic DRAW)
Code:
__DECY: SPPixelDown:
inc h inc h
ld a, h ld a, h
and 7 and 7
ret nz ret nz
ld a, h
sub 8
ld h, a
ld a, l ld a, l
add a, 32 add a, 32
ld l, a ld l, a
ret c ret nc
ld a, h ld a, h
sub 8 add a, 8
ld h, a ld h, a
ret cp $58
ccf
ret
Both this 2 routines do the same. :?: The one on the right seems optimized (It's used in ZX Basic DRAW)