menuMem = saveSScreen
;Now define where vars are located, 17 bytes required in all.
textbox_top     = menuMem
textbox_left    = textbox_top+1    ;needs to follow textbox_top
textbox_bottom  = menuMem+2
textbox_width   = textbox_bottom
textbox_right   = textbox_bottom+1 ;needs to follow textbox_bottom
menucallptr     = menuMem+4
menutop         = menuMem+6
menucur         = menuMem+8
menuselection   = menuMem+10
menuheader_ptr  = menuMem+12
menuheader_coord= menuMem+14
menuheader_cur  = menuMem+16  ;1 byte
menu_num_items  = menuMem+17  ;2 bytes
menu_get        = menuMem+19
menu_sel        = menuMem+21
menu_temp       = menuMem+23
menu_header_get = menuMem+25
menuopts        = menuMem+27
menudefault     = TempWord1
menutopinit     = TempWord4

#define MENU_MAX_ELEMENTS ((menuMem+768-menuopts)>>1)

;Menu:
;Get the y coordinate
  ld hl,(parsePtr)
  ld a,(hl)
  cp $AE
  jp z,fancymenu
  call p1_ParseFullArg
  push bc

;Get the x coordinate
  call p1_ParseNextFullArg
  pop hl
  ld h,c

;Save the coords
  ld (textbox_top),hl

; Get the width of the menu
  call p1_ParseNextFullArg
  ld (textbox_width),bc

;Get the header
  call p1_ParseNextFullArg
  ld (menuheader_ptr),bc

  ld hl,menuopts
  ld bc,0
menu_param_loop:
  inc bc
  ld a,b
  cp MENU_MAX_ELEMENTS>>8
  jr nz,+_
  ld a,c
  cp MENU_MAX_ELEMENTS&255
  jp menu_err
_:
  push bc
  push hl
  ld hl,(parsePtr)
  inc hl
  ld a,(hl)
  cp $AE
  jr z,menu_select_default

  call p1_ParseNextFullArg
  pop hl
  ld (hl),c
  inc hl
  ld (hl),b
  inc hl
  pop bc
  cp $2B
  jr z,menu_param_loop
_:
  ld de,0
  jr +_
menu_select_default:
  pop hl
  call p1_ParseNextFullArg
  ld h,b
  ld l,c
  dec hl
  pop bc
  dec bc
  ;If hl is negative, set DE to 0
  ld a,h
  add a,a
  jr c,-_
  ;set DE to min(HL,BC)
  ld d,b
  ld e,c
  dec de
  sbc hl,de
  jr nc,+_
  add hl,de
  ex de,hl
_:

  ld (menudefault),de

;Save the number of elements
  ld (menu_num_items),bc

  push bc
  call p1_chardim
  ld a,c
  ld (font_height),a
  pop bc
  ld l,a

;Now we need to render the menu, but first we'll get the height of the menu in pixels
;4+font_height*min(9-int(y/font_height),BC+1

;60/font_height-1 is the initial E value
  ld a,59
  ld e,-1

  inc e
  sub l
  jr nc,$-2

  ld a,(textbox_top)
  add a,a
  jr c,cmp_menu_height
  sla l
  .db $FE
_:
  dec e
  sub l
  jr nc,-_
cmp_menu_height:
;E is the max height
;if BC+1 is smaller, use that
  inc bc
  inc b
  dec b
  jr nz,+_
  ld a,c
  cp e
  jr nc,+_
  ld e,c
_:

;Now E is the number of items shown
;if menudefault>=E, then need to set menutopinit to menudefault-E+1
  ld hl,(menudefault)
  inc h
  dec h
  jr nz,$+6
  ld a,l
  sub e
  jr c,+_
  ld l,a
  jr nc,$+3
  inc h
  inc hl
  jr $+5
_:
  ld hl,0
  ld (menutopinit),hl

;now do E*FONT_HEIGHT+4, given that it won't overflow 8 bits
  ld a,(font_height)
  ld b,a
  ld a,5
_:
  add a,e
  djnz -_

;now set the width and height
  ld e,a
  ld a,(textbox_width)
  ld d,a

  ld ix,menu_command_lookup
  ld hl,menu_header_getter
  ld (menu_header_get),hl

menu_entry:
  ;Set the default graphics buffer
  ; ld hl,(BufPtr)
  ; ld (gbuf_temp),hl

;save and set the the font method
  ld a,(textmode)
  or a
  push af
  ld hl,(FontPointer)
  push hl
  jr nz,+_
  ld a,2
  ld (textmode),a
  ld hl,FontSet
  ld (FontPointer),hl
  xor a
  ld (font_ptr_page),a
_:
  ld bc,(textbox_top)
  ld hl,(menuheader_ptr)

  call menuroutine

  pop hl
  ld (FontPointer),hl
  xor a
  ld (font_ptr_page),a
  pop af
  ld (textmode),a
  ret

fancymenu:
;header,y,x,h,w,get,sel
  inc hl
  ld a,(hl)
  cp $AE
  push af
  jr nz,$+5
  ld (parsePtr),hl
  call p1_ParseNextFullArg
  ld (menuheader_ptr),bc

  call p1_ParseNextFullArg
  push bc
  call p1_ParseNextFullArg
  pop hl
  ld h,c
  ld (textbox_top),hl

  call p1_ParseNextFullArg
  push bc
  call p1_ParseNextFullArg
  pop hl
  ld h,c
  push hl ;w,h

  call p1_ParseNextFullArg
  ld (menu_get),bc

  call p1_ParseNextFullArg
  ld (menu_sel),bc

  call p1_chardim
  ld a,c
  ld (font_height),a

  ld hl,0
  ld (menutopinit),hl
  ld (menudefault),hl

  pop de

  pop af
  ld hl,menu_header_getter
  jr nz,$+5
  ld hl,menu_header_get_cb
  ld (menu_header_get),hl

  ld ix,fancymenu_lookup
  jp menu_entry


menu_err:
  ld hl,ErrStackOverflow_push
  ld (prev_page_call),hl
  jp prev_page_call

fancymenu_lookup:
;save the current parsePtr
  ld hl,(parsePtr)
  push hl

;save Ans and replace with the current cursor
  ld hl,(Ans)
  push hl

;save thetaprime
  ld hl,(ThetaPrimeVar)
  push hl

;Save the text coordinates
  ld hl,(TextRow)
  push hl

;Set ThetaPrime
  ld l,a
  ld h,0
  ld (ThetaPrimeVar),hl



;now set the location to start parsing at
  ld hl,(menu_get)
  jr nc,+_
  ld hl,(menu_sel)
  ld bc,(menucur)
_:
  ld (parsePtr),hl

;set Ans
  ld (Ans),bc

;Now parse
  call p1_ParserNext

;Restore text coordinates
  pop hl
  ld (TextRow),hl

;restore thetaprimevar
  pop hl
  ld (ThetaPrimeVar),hl

;restore Ans
  pop hl
  ld (Ans),hl

;restore parsePtr
  pop hl
  ld (parsePtr),hl

;return 0 if failed
  ld h,b
  ld l,c
  ld a,b
  or c
  ret nz
  scf
  ret


menu_command_lookup:
  jr c,menu_command_select
;get element number BC
  ld hl,(menu_num_items)
  scf
  sbc hl,bc
  ret c
  ld hl,menuopts
  add hl,bc
  add hl,bc
  ld a,(hl)
  inc hl
  ld h,(hl)
  ld l,a
  ret

menu_command_select:
  ld bc,(menucur)
  inc bc
  ret

menu_header_get_cb:
;save the current parsePtr
  ld hl,(parsePtr)
  push hl

;save Ans and replace with the current cursor
  ld hl,(Ans)
  push hl

;save thetaprime
  ld hl,(ThetaPrimeVar)
  push hl

;Save the text coordinates
  ld hl,(TextRow)
  push hl

;Set "Ans"
  ld c,a
  ld b,0

;now set the location to start parsing at
  ld hl,(menuheader_ptr)
  ld (parsePtr),hl

;set Ans
  ld (Ans),bc

;Now parse
  call p1_ParserNext

;Restore text coordinates
  pop hl
  ld (TextRow),hl

;restore thetaprimevar
  pop hl
  ld (ThetaPrimeVar),hl

;restore Ans
  pop hl
  ld (Ans),hl

;restore parsePtr
  pop hl
  ld (parsePtr),hl

;return 0 if failed
  ld h,b
  ld l,c
  ld a,b
  or c
  ret nz
  ld hl,s_null
  ret