angle targetting

  ; simpler movement
  lda keydown,x
  and #15
  tay
  lda TargetAngles,y
  bmi ExitToNotCar   ; not a valid angle to target
  sta target ; target = target

  lda PlayerShootAngle,x
  sta current
  sub target
  bpl :+ ; absolute value
  eor #255
  add #1
: sta difference ; difference = the absolute value of the difference
  beq ExitToNotCar  ; difference = target? don't turn

  cmp #16 ; turning 180 degrees? just instantly flip
  bne :+
   lda PlayerShootAngle,x
   add #16
   sta PlayerShootAngle,x
   jmp ExitToNotCar
:

  cmp #16
  bcs :+
  lda current
  cmp target
  bcc :+
  dec PlayerShootAngle,x
  jmp ExitToNotCar
:

  lda difference
  cmp #16
  bcc :+
  lda current
  cmp target
  bcs :+
  dec PlayerShootAngle,x
  jmp ExitToNotCar
:

  inc PlayerShootAngle,x
ExitToNotCar:
  lda PlayerShootAngle,x ; restrict to the range of target-31
  and #31
  sta PlayerShootAngle,x
  jmp NotRacecar

TargetAngles: ;up, down, left, right
.byt <-1,  0, 16, <-1,  8,  4, 12, <-1
.byt 24, 28, 20, <-1, <-1, <-1, <-1, <-1