an early ChucK synth

launchpad_0.ck

MidiIn padIn;
MidiOut padOut;
MidiMsg msg;
1.059463094359295 => float halfStepRatio;
TriOsc mrNote => dac;
0 => mrNote.gain;
55.0 => float lowestFreq;
8 => int rowStep;	// number of halfsteps between launchpad rows.
					// set to 8 for a chromatic layout.  Anything above
					// 8 and you'll miss notes.  Anything below and
					// notes will have multiple keys.

if(!padIn.open(0))
	me.exit();

if(!padOut.open(0))
	me.exit();

while(true) {
	padIn => now;
	while(padIn.recv(msg)) {
		<<< msg.data1, msg.data2, msg.data3, keyToFreq(msg.data2) >>>;
		if(msg.data3 == 127) {
			bounce(msg);
			noteOn(keyToFreq(msg.data2));
		} else {
			bounce(msg);
			noteOff(keyToFreq(msg.data2));
		}
	}
}

fun float keyToFreq(int key) {
	key % 16 => int column;
	key / 16 => int row;
	return lowestFreq * max(1, exp(halfStepRatio, ((7 - row) * rowStep + column)));
}

fun void noteOn(float freq) {
	freq => mrNote.freq; 
	0.8 => mrNote.gain;
}

fun void noteOff(float freq) {
	0 => mrNote.gain;
}

fun void bounce(MidiMsg msg) {
	padOut.send(msg);
}

fun float max(float a, float b) {
	if (a > b)
		return a;
	else
		return b;
}

// now this is truly awful.
fun float exp(float base, int power) {
	base => float ret;
	if(power < 0)
		me.exit();
	else if(power == 0)
		return 1.0;
	else {
		while(power > 1) {
			ret * base => ret;	
			power - 1 => power;
		}
		return ret;
	}
}