;;rotletencrypt
;;Encrypts a string in rot-x (uses $41 to $5B)
;;Inputs:
;; HL: string pointer
;; A: x
;;Notes:
;; Changes string in place.
rotletencrypt:
 push hl
  push bc
   ld c, 0
   ld c, a
rotletencryptLoop:
   ld a, (hl)
   cp 0
   jr z, rotletencryptEnd
   add a, c
   cp 0
   jr nz, rotletencryptLd
   inc a
rotletencryptLd:
   ld (hl), a
   inc hl
   cp a, $5c
   jr c, rotletencryptLoop
   dec hl
   sub a, 'Z' + 1 - 'A'
   ld (hl), a
   inc hl
   jr rotletencryptLoop
rotletencryptEnd:
   ld (hl), $00
  pop bc
 pop hl
 ret

;;rotletdecrypt
;;Encrypts a string in rot-x (uses $41 to $5B)
;;Inputs:
;; HL: string pointer
;; A: x
;;Notes:
;; Changes string in place.
rotletdecrypt:
 push hl
  push bc
   ld c, 0
   ld c, a
rotletdecryptLoop:
   ld a, (hl)
   cp 0
   jr z, rotletdecryptEnd
   sub a, c
rotletdecryptLd:
   ld (hl), a
   inc hl
   cp a, $5c
   jr c, rotletdecryptLoop
   dec hl
   add a, 'Z' + 1 - 'A'
   ld (hl), a
   inc hl
   jr rotletdecryptLoop
rotletdecryptEnd:
   ld (hl), $00
  pop bc
 pop hl
 ret

;;rotasciiencrypt
;;Encrypts a string in rot-x (uses $00 to $EF)
;;Inputs:
;; HL: string pointer
;; A: x
;;Notes:
;; Changes string in place.
rotasciiencrypt:
 push hl
  push bc
   ld c, 0
   ld c, a
rotasciiencryptLoop:
   ld a, (hl)
   cp 0
   jr z, rotasciiencryptEnd
   add a, c
   cp 0
   jr nz, rotasciiencryptLd
   inc a
rotasciiencryptLd:
   ld (hl), a
   inc hl
   cp a, $EF
   jr c, rotasciiencryptLoop
   dec hl
   sub a, $0F
   ld (hl), a
   inc hl
   jr rotasciiencryptLoop
rotasciiencryptEnd:
   ld (hl), $00
  pop bc
 pop hl
 ret

;;rotasciidecrypt
;;Encrypts a string in rot-x (uses $00 to $EF)
;;Inputs:
;; HL: string pointer
;; A: x
;;Notes:
;; Changes string in place.
rotasciidecrypt:
 push hl
  push bc
   ld c, 0
   ld c, a
rotasciidecryptLoop:
   ld a, (hl)
   cp 0
   jr z, rotasciidecryptEnd
   sub a, c
   cp 0
   jr nz, rotasciidecryptLd
   dec a
rotasciidecryptLd:
   ld (hl), a
   inc hl
   cp a, $EF
   jr c, rotasciidecryptLoop
   dec hl
   add a, $0F
   ld (hl), a
   inc hl
   jr rotasciidecryptLoop
rotasciidecryptEnd:
   ld (hl), $00
  pop bc
 pop hl
 ret