NESkode2

.segment "INES"
    .byte "NES", $1A,1,1,9

.segment "VECTORS"
    .word NMI
    .word Start
    .word IRQ

.segment "GFX"
spr_tiles:
    .incbin "sprites.spr"
bg_tiles:
    .incbin "bakgrunn.chr"

.segment "CODE"

Start:

    ; ---[ VENTER 2 FRAMES TIL PPU KOMMER SEG ]---
    LDA $2002
    BPL Start
:   LDA $2002
    BPL :-

    ; ---[ START LAST PALETT]---
    LDA #$3F
    STA $2006   ; PPU output skal
    LDA #0      ; settes til $3F00
    STA $2006

    LDX #0
LastPalett:
    LDA palett, x
    STA $2007
    INX
    CPX #32
    BNE LastPalett
    ; ---[ SLUTT LAST PALETT]---

    ; ---[ SETTER OPP PPU ]---
    LDA #%10010000
    STA $2000       ; kontrollregister 1
    LDA #%00011110
    STA $2001       ; kontrollregister 2

    ; ---[ SETTER OPP STACKEN ]---
    LDX #$FF
    TXS


    LDA #0
    STA right_racket_pos

    ; ---[ SETT POSISJON TIL SPRITES ]---

    ; ---[ POSISJONER OG VEKTORER TIL BALLEN]---
    LDA #0
    STA x_pos
    LDA #50
    STA y_pos
    LDA #3
    STA x_vector
    LDA #1
    STA y_vector

Sprite:
    LDA $2002
    BPL Sprite


    ; ---[ BALL ]---

    ; ---[ Y-KOORDINAT ]---
    LDA y_pos
    STA ball_y

    ; ---[ TILENUMMER FRA CHR-ROM ]---
    LDA #3
    STA ball_tile
    ; ---[ ATRIBUTT-BYTE ]---
    LDA #0; (setter ingen flagg)
    STA ball_attribute
    ; ---[ X-KOORDINAT ]---
    LDA x_pos
    STA ball_x


    ; ---[ RIGHT RACKET ]---

    ; ---[ Y-KOORDINAT ]---
    LDA right_racket_pos
    STA racket_y
    ; ---[ TILENUMMER FRA CHR-ROM ]---
    LDA #5
    STA racket_tile
    ; ---[ ATRIBUTT-BYTE ]---
    LDA #0; (setter ingen flagg)
    STA racket_attribute
    ; ---[ X-KOORDINAT ]---
    LDA #250
    STA racket_x


    ; ---[RIGHT RACKET POSITION ]---
    ;A, B, Select, Start, Up, Down, Left, Right
    LDA #1
    STA $4016
    LDA #0
    STA $4016
    LDA $4016 ; A
    LDA $4016 ; B
    LDA $4016 ; Select
    LDA $4016 ; Start
    LDA $4016 ; Up
    CMP #$41
    BNE NotUp
    LDA right_racket_pos
    SEC
    SBC #2
    STA right_racket_pos
    JMP NoMove

NotUp:
    LDA $4016 ; Down
    CMP #$41
    BNE NoMove
    LDA right_racket_pos
    CLC
    ADC #2
    STA right_racket_pos

NoMove:



    ; ---[ OPPDATERER X ]---
    LDA x_pos
    CLC
    ADC x_vector
    TAX
    STA x_pos

    ; ---[ OPPDATERER Y ]---
    LDA y_pos
    CLC
    ADC y_vector
    TAY
    STA y_pos

    ; ---[ TRUFFET KANTEN? ]---
;TestEdgeX
    CPX #250    ; if (x >= 250)
    BCS TurnX   ; then TurnX
    CPX #0      ; if (x == 0)
    BEQ TurnX   ; then TurnX

TestEdgeY:
    CPY #232    ; if (y >= 232)
    BCS TurnY   ; then TurnY
    CPY #0      ; if (y == 0)
    BEQ TurnY   ; then TurnY

    JMP Sprite ; ikke truffet kanten, flytt mer


TurnX: ; SNUR X-VEKTOREN
    LDA #0
    SEC
    SBC x_vector
    STA x_vector
    JMP TestEdgeY


TurnY: ; SNUR Y-VEKTOREN
    LDA #0
    SEC
    SBC y_vector
    STA y_vector
    JMP Sprite



palett:
    ; Bakgrunnsgrafikk
    .byte 0, $2E, $2D, $04
    .byte 0, $2E, $2D, $04
    .byte 0, $2E, $2D, $04
    .byte 0, $2E, $2D, $04

    .byte $11, $2A, $28, $21    ; bakgrunn og sprite 0
    .byte 0, 0, 0, 0            ; sprite 1
    .byte 0, 0, 0, 0            ; sprite 2
    .byte 0, 0, 0, 0            ; sprite 3





NMI: ; ---[ V-BLANK INTERRUPT ]---
    STA a_tmp
    ;STX x_tmp
    ;STY y_tmp

    LDA #$00
    STA $2003
    LDA #$02
    STA $4014

    LDA a_tmp
    ;LDX x_tmp
    ;LDY y_tmp
    RTI ; ReTurn from Interrupt

IRQ:
    jmp IRQ

.segment "RAM"
    ; Midlertidige minneposisjoner for interrupt handling
    a_tmp:              .byte 0
    x_tmp:              .byte 0
    y_tmp:              .byte 0

    ; Ballen
    x_pos:              .byte 0
    y_pos:              .byte 0
    x_vector:           .byte 0
    y_vector:           .byte 0

    ; Racketen
    right_racket_pos:   .byte 0

    .org $0200
    ball_y:             .byte 0
    ball_tile:          .byte 0
    ball_attribute:     .byte 0
    ball_x:             .byte 0

    racket_y:           .byte 0
    racket_tile:        .byte 0
    racket_attribute:   .byte 0
    racket_x:           .byte 0