uxn/projects/examples/devices/audio.usm

( dev/audio )

%MOD { DUP2 DIV MUL SUB }

@timer    $1
@progress $1

( devices )

|00 @System     [ &vector $2 &pad    $6 &r      $2 &g     $2 &b      $2 ]
|20 @Screen     [ &vector $2 &width  $2 &height $2 &pad   $2 &x      $2 &y    $2 &addr  $2 &color $1 ]
|30 @Audio      [ &pad $8 &adsr $2 &len $2 &addr $2 &volume $1 &pitch $1 ]

|0100 ( -> )
	
	( set color pallete )
	#00ff .System/r DEO2 
	#0f0f .System/g DEO2 
	#0ff0 .System/b DEO2 

	;on-frame .Screen/vector DEO2 ( run on-frame every 1/60th of a second )
	#ff .Audio/volume DEO         ( set volume to max )
	;saw .Audio/addr DEO2         ( set waveform to saw for audio engine )
	;saw/end ;saw SUB2 .Audio/len DEO2
	#1202 .Audio/adsr DEO2        ( set envelope for audio engine )

BRK

@on-frame ( -> )

	( incr ) .timer PEK #01 ADD .timer POK 
	( skip ) .timer PEK #10 EQU ,&play-note JNZ BRK &play-note

	( get note )
	;melody #00 .progress PEK ADD2 GET 

	( play note )
	DUP .Audio/pitch DEO

	( erase last note )
	#20  .Screen/color DEO

	( draw note )
	#00 SWP #0004 MUL2 #0100 SUB2 .Screen/y DEO2
	#00 .progress PEK #0008 MUL2 .Screen/x DEO2
	;dot .Screen/addr DEO2
	#21 .Screen/color DEO

	( incr ) .progress PEK #01 ADD #20 MOD .progress POK

	#00 .timer POK

BRK

@silence ( -> )

BRK

( defines a sawtooth wave. )

@saw ( -> )
	5f5f 5e5e 5e5d 5d5d 5c5c 5b5b 5b5a 5a5a
	5959 5858 5857 5757 5656 5555 5554 5454
	5353 5252 5251 5151 5050 4f4f 4f4e 4e4e
	4d4d 4c4c 4c4b 4b4b 4a4a 4949 4948 4848
	4747 4646 4645 4545 4444 4343 4342 4242
	4141 4040 403f 3f3f 3e3e 3d3d 3d3c 3c3c
	3b3b 3a3a 3a39 3939 3838 3737 3736 3636
	3535 3434 3433 3333 3232 3131 3130 3030
	2f2f 2e2e 2e2d 2d2d 2c2c 2b2b 2b2a 2a2a
	2929 2828 2827 2727 2626 2525 2524 2424
	2323 2222 2221 2121 2020 1f1f 1f1e 1e1e
	1d1d 1c1c 1c1b 1b1b 1a1a 1919 1918 1818
	1717 1616 1615 1515 1414 1313 1312 1212
	1111 1010 100f 0f0f 0e0e 0d0d 0d0c 0c0c
	0b0b 0a0a 0a09 0909 0808 0707 0706 0606
	0505 0404 0403 0303 0202 0101 0100 0000
	&end

BRK

( song data, #ff is used for a rest )

@melody [ 
	54 52 54 4f 4b 4f 48 ff
	54 52 54 4f 4b 4f 48 ff
	54 56 57 56 57 54 56 54 
	56 52 54 52 54 50 54 ff
] 

( dot sprite )
	 
@dot [ 003c 7eff 7e3c 0000 ]