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Code: Select all

_ppu_waitnmi:
	lda #1
	sta <VRAMUPDATE
	lda <FRAMECNT1
@1:
	cmp <FRAMECNT1
	beq @1
	lda <NTSCMODE
	beq @3
@2:
	lda <FRAMECNT2
	cmp #5
	beq @2
@3:
	lda #0
	sta <VRAMUPDATE
	rts


_scroll:
	sta <TEMP

	txa
	bne @1
	lda <TEMP
	cmp #240
	bcs @1
	sta <SCROLL_Y
	lda #0
	sta <TEMP
	beq @2	;bra

@1:
	sec
	lda <TEMP
	sbc #240
	sta <SCROLL_Y
	lda #2
	sta <TEMP
@2:

	jsr popax
	sta <SCROLL_X
	txa
	and #$01
	ora <TEMP
	sta <TEMP
	lda <PPU_CTRL_VAR
	and #$fc
	ora <TEMP
	sta <PPU_CTRL_VAR
	rts

Code: Select all

;void __fastcall__ waitSprite0rel(void);

_waitSprite0rel:
	lda #1 ;no idéa what these two lines do, took it from ppu_waitnmi()
	sta <VRAMUPDATE ;but I think the sprites didn't even show up if I didn't include them = /
	lda $2002
	and #$40
	beq _waitSprite0rel
	rts
   
;void __fastcall__ waitSprite0set(void);
   
_waitSprite0set:
	lda $2002
	and #$40
	bne _waitSprite0set
;	lda $2000
;	and #$FE
;	sta $2000
	lda #0 ;same as above, these two are from ppu_waitnmi()
	sta <VRAMUPDATE
	rts
  
;void __fastcall__ waitVBLANKrel(void);
   
_waitVBLANKrel:	
	lda <FRAMECNT1
_waitVBLANKloop:
	cmp <FRAMECNT1
	beq _waitVBLANKloop
	lda #0 ;same as above, these two are from ppu_waitnmi()
	sta <VRAMUPDATE
	rts

Code: Select all

updateEverything();

scroll(0, scrollY);
waitSprite0rel(); // waits until rendering starts?
waitSprite0set(); // waits for sprite 0 hit?
scroll(scrollX, scrollY); // scrolls screen directly after hit
waitVBLANKrel(); // waits for rendering to end!?