Add NES building and adapt example functions

LibMultiSpacc/neslib/pad.s

@@ -0,0 +1,89 @@
+
+.segment "ZEROPAGE"
+
+PAD_STATE: 		.res 2		;one byte per controller
+PAD_STATEP: 		.res 2
+PAD_STATET: 		.res 2
+
+.importzp		TEMP
+PAD_BUF			=TEMP+1
+
+.include "nes.inc"
+.segment "CODE"
+.export _pad_poll, _pad_trigger, _pad_state
+
+;unsigned char __fastcall__ pad_poll(unsigned char pad);
+
+_pad_poll:
+
+	tay
+	ldx #0
+
+@padPollPort:
+
+	lda #1
+	sta CTRL_PORT1
+	lda #0
+	sta CTRL_PORT1
+	lda #8
+	sta <TEMP
+
+@padPollLoop:
+
+	lda CTRL_PORT1,y
+	lsr a
+	ror <PAD_BUF,x
+	dec <TEMP
+	bne @padPollLoop
+
+	inx
+	cpx #3
+	bne @padPollPort
+
+	lda <PAD_BUF
+	cmp <PAD_BUF+1
+	beq @done
+	cmp <PAD_BUF+2
+	beq @done
+	lda <PAD_BUF+1
+
+@done:
+
+	sta <PAD_STATE,y
+	tax
+	eor <PAD_STATEP,y
+	and <PAD_STATE ,y
+	sta <PAD_STATET,y
+	txa
+	sta <PAD_STATEP,y
+
+	ldx #$00
+	rts
+
+
+
+;unsigned char __fastcall__ pad_trigger(unsigned char pad);
+
+_pad_trigger:
+
+	pha
+	jsr _pad_poll
+	pla
+	tax
+	lda <PAD_STATET,x
+	ldx #$00
+	rts
+
+
+
+;unsigned char __fastcall__ pad_state(unsigned char pad);
+
+_pad_state:
+
+	tax
+	lda <PAD_STATE,x
+	ldx #$00
+	rts
+
+
+