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.globl _ubox_set_sprite_pat16_flip
WRTVRM = 0x004d
SP_PATTERNS = 0x3800
_ubox_set_sprite_pat16_flip::
ld hl, #2
add hl, sp
ld e, (hl)
inc hl
ld d, (hl)
inc hl
ld l, (hl)
ld h, #0
add hl, hl
add hl, hl
add hl, hl
add hl, hl
add hl, hl
ld bc, #SP_PATTERNS
add hl, bc
push de
ld bc, #16
ex de, hl
add hl, bc
ex de, hl
call flip
pop de
call flip
ret
flip:
ld b, #16
flip0:
call flip_and_copy
inc hl
inc de
djnz flip0
ret
flip_and_copy:
ld a, (de)
ld c, a
rlca
rlca
xor c
and #0xaa
xor c
ld c, a
rlca
rlca
rlca
rrc c
xor c
and #0x66
xor c
jp WRTVRM
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