// ***********************************
//  nas test extension
// ***********************************

.struct 0
	VMEM_LFO:	.space 1
	
	.text
	.align
//------------------------------------------------------------------------------
// program header
//------------------------------------------------------------------------------

.global nasTestProgram

nasTestProgram:
	.word	START		// program binary start
	.hword	(END-START)/4	// program binary size
	.hword	0		// ???
	.byte	0		// global memory alloc
	.byte	0		// channel memory alloc
	.byte	1		// voice memory alloc
	.byte	4		// modifier flags
	
	

	
.align
//==============================================================================
START:
//==============================================================================

//------------------------------------------------------------------------------
// program vectors
//------------------------------------------------------------------------------
	.word	reset-START		// global:reset
	.word	0			// global:pulse	
	.word	0			// global:tick
	.word	0			// global:user
	.word	0			// global:preprocess	
	.word	0			// global:postprocess
	.word	0			// global:reserved1
	.word	0			// global:reserved2
	.word	0			// channel:reset
	.word	0			// channel:pulse
	.word	0			// channel:tick
	.word	0			// channel:user
	.word	0			// channel:reserved1
	.word	0			// channel:reserved2
	.word	0			// channel:reserved3
	.word	0			// channel:reserved4
	.word	voice_newnote-START	// voice:newnote
	.word	0			// voice:pulse
	.word	voice_tick-START	// voice:tick
	.word	0			// voice:user
	.word	0			// voice:losefocus
	.word	0			// voice:release
	.word	0			// voice:reserved1
	.word	0			// voice:reserved2

	.arm
//==============================================================================
reset:
//==============================================================================
	mov	r0, #5
	add	r0, #6
	bx	lr

	
voice_newnote:				@ reset lfo position
	mov	r3, #0			@
	strb	r3, [r2, #VMEM_LFO]	@
	bx	lr			@
	
voice_tick:
	push	{r0}
	ldrb	r0, [r2, #VMEM_LFO]
	add	r0, #3
	strb	r0, [r2, #VMEM_LFO]
	
	push	{r1,lr}
	bl	get_sine
	
	@mov	r1, #128
	@add	r0, r1, r0, asr#8
	pop	{r1,lr}
	
	mov	r0, r0, asr#12
	
	
	strb	r0, [r1, #4] @ mod:panning
	mov	r0, #2<<2
	strb	r0, [r1, #7] @ mod:modes
	pop	{r0}
	ldrb	r1, [r0, #7] @ df|=panning
	orr	r1, #4
	strb	r1, [r0, #7]
	bx	lr
	
@--------------------------------------------------------------------------
get_sine:
	movs	r1, r0, lsr#6
	ands	r1, #0x3
	and	r0, #0x3F
	beq	.first_4th
	cmp	r1, #2
	beq	.third_4th
	blt	.second_4th
.fourth_4th:
	swi	0x1A0000
	sub	r0, #0x8000
	bx	lr
.third_4th:
	swi	0x1A0000
	rsb	r0, r0, #0
	bx	lr
.second_4th:
	swi	0x1A0000
	rsb	r0, r0, #0x8000
	bx	lr
.first_4th:
	swi	0x1A0000
	bx	lr
	
.pool

.align
END: