mirror of https://github.com/nmlgc/ReC98.git
29 lines
429 B
NASM
29 lines
429 B
NASM
|
; Generates a lookup table for flipping one byte, interpreted as a horizontal
|
||
|
|
; line of 8 pixels in a single bitplane.
|
||
|
|
|
||
|
|
; int DEFCONV hflip_lut_generate()
|
||
|
|
proc_defconv hflip_lut_generate
|
||
|
|
push di
|
||
|
|
xor ax, ax
|
||
|
|
mov di, offset hflip_lut
|
||
|
|
xor dl, dl
|
||
|
|
jmp short @@check
|
||
|
|
|
||
|
|
@@outer:
|
||
|
|
xor dl, dl
|
||
|
|
mov cx, 8
|
||
|
|
|
||
|
|
@@inner:
|
||
|
|
rol al, 1
|
||
|
|
rcr dl, 1
|
||
|
|
loop @@inner
|
||
|
|
|
||
|
|
@@check:
|
||
|
|
mov [di], dl
|
||
|
|
inc di
|
||
|
|
inc al
|
||
|
|
jnz short @@outer
|
||
|
|
pop di
|
||
|
|
ret
|
||
|
|
endp_defconv
|