pixLUT:
  .db $80,$40,$20,$10,$08,$04,$02,$01
GetPixelLoc:
;Input:
;     b is X
;     c is y
;Output:
;     HL points to byte
;     A is the mask
;     nc if not computed, c if computed
;Speed: 192+17{1,2,3,4,5,6,7,8}
;Avg: 268.5cc
;185cc
  ld a,c
  cp 64
  ret nc
  add a,a
  add a,a
  ld c,a
  ld a,b
  cp 96
  ret nc

  ld b,0
  ld hl,(gbuf_temp)
  add hl,bc
  add hl,bc
  add hl,bc
  ld c,a
  srl c
  srl c
  srl c
  add hl,bc
  and 7
  ld b,pixLUT>>8
  add a,pixLUT&255
  ld c,a
#if pixLUT&255>249
  jr nc,$+3
  inc b
#endif
  ld a,(bc)
  scf
  ret