var SCENE_BLACK = 0;
var SCENE_WHITE = 1;

var TIME_SIG = 4;

function e4s(s) {
    var n = new NoteOn();
    n.pitch = s;
    return n;
}

function strobe(startTime, scene1, scene2, subdivision, length) {
    var i = startTime;
    var s1e = e4s(scene1);
    var s2e = e4s(scene2);

    s2e.pitch = scene2;

    while (i < (startTime +length)) {
	s1e.sendAfterBeats(i);
	i += subDivision;
	s2e.sendAfterBeats(i);
    }
    return i;
}

function fastBlackWhiteFlash() {
    strobe(SCENE_BLACK, SCENE_WHITE, 1/32.0, 1/4.0);
}

function fourBarWithFill(scene1, scene2) {
    strobe(0, scene1, scene2, 2, 12);
    strobe(12, scene1, scene2, 1/4.0, 2);
    strobe(3.5, scene1, scene2, 1/8.0, 2);
}

function scene2AsFill(scene1, scene2) {
    e4s(scene1).send();
    e4s(scene2).sendAfterBeats(12);
}

function as44(start, s1, s2, s3, s4) {
    e4s(s1).sendAfterBeats(start);
    e4s(s2).sendAfterBeats(start+1);
    e4s(s3).sendAfterBeats(start+2);
    e4s(s4).sendAfterBeats(start+3);
    return 4;
}

function tripletStrobe(start, s1, s2, s3, duration) {
    i = start;
    e1 = e4s(s1);
    e2 = e4s(s2);
    e3 = e4s(s3);

    while (i < duration) {
	e1.sendAfterBeats(i);
	e2.sendAfterBeats(i+(1/3.0));
	e3.sendAfterBeats(i+(2/3.0));
	i += 1.0;
    }
}

function jazz1(s1, s2, s3, s4) {
    i = 0;
    i = as44(i, s1, s2, s3, s4);
    i = as44(i, s1, s2, s3, s4);
    i = as44(i, s1, s2, s3, s4);
    i = strobe(i, s2, s1, 1, 2);
    tripletStrobe(i, s2, s3, s4, 2);
}