#IFNDEF __lib_utils
#DEFINE __lib_utils 1

GOTO __skip_lib_utils

FUNC fill_mem({WORD start_addr @ $fb} {WORD end_addr} {BYTE value})

  FOR start_addr = start_addr TO end_addr
    POKE start_addr , value
  NEXT
FEND

FUNC mem_copy({WORD start_addr @ $fb} {WORD end_addr} {WORD target_addr @ $fd})
  BYTE value

  FOR start_addr = start_addr TO end_addr
    value = PEEK start_addr
    POKE target_addr , value
    target_addr++
  NEXT
FEND


FUNC mem_copy_range({WORD start_addr @ $fb} {WORD target_addr @ $fd} {WORD range})
  BYTE value

  WHILE range
    value = PEEK start_addr
    POKE target_addr , value
    start_addr++
    target_addr++
    range--
  WEND
FEND

FUNC set_vic_bank({BYTE bank})

  ASM
    lda $dd02
    ora #3
    sta $dd02

    ; sanitize and reverse value (so bank 0 = $0000. bank 1 = $4000 etc)
    lda |bank|
    and #3
    eor #3
    sta |bank|


    lda $dd00
    and #%11111100
    ora |bank|
    sta $dd00
  ENDASM
FEND


// Screen mem goes in banks of $0400
// 0=$0000
// 1=$0400
// 2=$0800
// ...
FUNC set_vic_screenmem({BYTE screenmem})

  ASM
    ; sanitize screenmem and move to relevant $d018 bits
    lda |screenmem|
    and #$0f
    clc
    rol
    rol
    rol
    rol
    sta |screenmem|

    lda $d018
    and #$0f
    ora |screenmem|
    sta $d018
  ENDASM

FEND

// Char mem goes in banks of $0800
// 0=$0000
// 1=$0800
// 2=$1000
// ...
// (Bitmaps in banks of $2000)
// 0=$0000
// 4=$2000
FUNC set_vic_charmem({BYTE charmem})

  ASM
    ; sanitize charmem and move to relevant $d018 bits
    lda |charmem|
    and #%00000111
    clc
    rol
    sta |charmem|

    lda $d018
    and #$f0
    ora |charmem|
    sta $d018
  ENDASM

FEND

FUNC set_vic_ecm
  ASM
    lda $d011
    and #$1f ; leave DEN bit + all scroll stuff
    ora #64
    sta $d011
  ENDASM
FEND

// Wait for a keypress using direct CIA keyboard scan
// No interrupts needed
FUNC wait_key
  BYTE row @ $dc01
  BYTE col @ $dc00

  // Wait for NO key pressed first (debounce)
  col = 0
  WHILE row <> $ff
  WEND

  // Now wait for ANY key pressed
  WHILE row == $ff
  WEND

  // Wait for key release (debounce)
  WHILE row <> $ff
  WEND
FEND

FUNC save_zeropage
  mem_copy_range($0000, $cf00, 256)
FEND

FUNC restore_zeropage
  mem_copy_range($cf00, $0000, 256)
FEND

LABEL __skip_lib_utils

#IFEND