add multiple features

1. dpcm (temporary boilerplate needed, sorry)
2. noise
3. volume
4. multiline comments

waves.txt

@@ -1,61 +1,6 @@
-TOTAL_DURATION(10000)
+TOTAL_DURATION(3000)  // 3 seconds total
 
-SQUARE 0 400 392 0.7
-SAWTOOTH 0 400 392 0.4
-SINE 0 400 392 0.3
-TRIANGLE 0 400 392 0.2
-
-SQUARE 450 400 392 0.7
-SAWTOOTH 450 400 392 0.4
-SINE 450 400 392 0.3
-TRIANGLE 450 400 392 0.2
-
-SQUARE 900 800 440 0.7
-SAWTOOTH 900 800 440 0.4
-SINE 900 800 440 0.3
-TRIANGLE 900 800 440 0.2
-
-SQUARE 1800 800 392 0.7
-SAWTOOTH 1800 800 392 0.4
-SINE 1800 800 392 0.3
-TRIANGLE 1800 800 392 0.2
-
-SQUARE 2700 800 523 0.7
-SAWTOOTH 2700 800 523 0.4
-SINE 2700 800 523 0.3
-TRIANGLE 2700 800 523 0.2
-
-SQUARE 3600 1600 494 0.7
-SAWTOOTH 3600 1600 494 0.4
-SINE 3600 1600 494 0.3
-TRIANGLE 3600 1600 494 0.2
-
-SQUARE 5400 400 392 0.7
-SAWTOOTH 5400 400 392 0.4
-SINE 5400 400 392 0.3
-TRIANGLE 5400 400 392 0.2
-
-SQUARE 5850 400 392 0.7
-SAWTOOTH 5850 400 392 0.4
-SINE 5850 400 392 0.3
-TRIANGLE 5850 400 392 0.2
-
-SQUARE 6300 800 440 0.7
-SAWTOOTH 6300 800 440 0.4
-SINE 6300 800 440 0.3
-TRIANGLE 6300 800 440 0.2
-
-SQUARE 7200 800 392 0.7
-SAWTOOTH 7200 800 392 0.4
-SINE 7200 800 392 0.3
-TRIANGLE 7200 800 392 0.2
-
-SQUARE 8100 800 587 0.7
-SAWTOOTH 8100 800 587 0.4
-SINE 8100 800 587 0.3
-TRIANGLE 8100 800 587 0.2
-
-SQUARE 9000 1600 523 0.7
-SAWTOOTH 9000 1600 523 0.4
-SINE 9000 1600 523 0.3
-TRIANGLE 9000 1600 523 0.2
+SINE 0 1000 440 1.0 0 3 5 0.05 0.3    // sine with slow vibrato and long decay
+SQUARE 500 1000 330 0.7 0.25 6 4 0.01 0.2  // square with duty cycle and sweep
+NOISE 1500 400 0 0.8 0 0 0 0.02 0.1  // noise burst
+DPCM 2000 800 /* boilerplate */ 0 0 0 0 0 0 1.0 snare.wav