Garciat/ondulator.html

## ondulator.html
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Ondulator</title>

    <script>
const PI = Math.PI;
const TAU = 2 * PI;
const RR = 50;
let CW = 800;
let CH = 800;

function resize(canvas) {
    CW = CH = 0.9 * Math.min(document.body.clientWidth, document.body.clientHeight);
    canvas.width = CW;
    canvas.height = CH;
}

function clear(ctx) {
    ctx.save();
    ctx.translate(0, 0);
    ctx.clearRect(0, 0, CW, CH);
    ctx.fillStyle = 'black';
    ctx.fillRect(0, 0, CW, CH);
    ctx.restore();
}

function drawOndulator(ctx, color, width, radius, nodes, state, rotation) {
    ctx.save();

    const sliceR = TAU / nodes;
    const stepR = sliceR / RR;
    const k = state * radius * Math.sin(sliceR / 2);

    ctx.translate(CW/2, CH/2);
    ctx.rotate(rotation);

    ctx.lineWidth = width;
    ctx.strokeStyle = color;

    for (let i = 0; i < nodes; ++i) {
        ctx.beginPath();
        ctx.moveTo(0, radius);

        for (let j = 0; j < RR + 2; ++j) {
            const r = radius + Math.pow(-1, i) * k * Math.sin(PI * j / RR);
            const x = r * Math.sin(j * stepR);
            const y = r * Math.cos(j * stepR);

            ctx.lineTo(x, y);
        }

        ctx.stroke();
        ctx.rotate(sliceR);
    }

    ctx.restore();
}

function main() {
    const canvas = document.createElement('canvas');
    document.body.appendChild(canvas);
    document.body.style.margin = '0px';
    document.body.style.display = 'flex';
    document.body.style.alignItems = 'center';
    document.body.style.justifyContent = 'center';

    const ctx = canvas.getContext('2d');

    const modes = 2;
    let mode = 0;

    canvas.addEventListener('click', () => {
        mode = (mode + 1) % modes;
    });

    function loop(t) {
        clear(ctx);
        ctx.globalCompositeOperation = 'lighten';

        switch (mode) {
        case 0:
            drawOndulator(ctx, 'rgba(255, 255, 255, 1)', 0.08 * CW / 2, 0.75 * CW / 2, 12, 0.5 * +Math.sin(t / 500), t/2500);
            drawOndulator(ctx, 'rgba(255, 255, 255, 1)', 0.08 * CW / 2, 0.75 * CW / 2, 12, 0.5 * -Math.sin(t / 500), t/2500);
            break;
        case 1:
            drawOndulator(ctx, 'rgba(255, 0, 0, 1)',   0.1 * CW / 2, 0.75 * CW / 2, 12, 0.5 * +Math.sin(t / 500), t/2500);
            drawOndulator(ctx, 'rgba(0, 255, 255, 1)', 0.1 * CW / 2, 0.75 * CW / 2, 12, 0.5 * -Math.cos(t / 500), t/2500);
            drawOndulator(ctx, 'rgba(0, 255, 0, 1)',   0.1 * CW / 2, 0.75 * CW / 2, 12, 0.5 * +Math.cos(t / 500), t/2500);
            break;
        }

        requestAnimationFrame(loop);
    }

    resize(canvas);
    requestAnimationFrame(loop);
}

window.addEventListener('load', main);
    </script>
</head>
<body style="background-color: black">

</body>
</html>
	<html lang="en">
	<head>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta http-equiv="X-UA-Compatible" content="ie=edge">
	<title>Ondulator</title>

	<script>
	const PI = Math.PI;
	const TAU = 2 * PI;
	const RR = 50;
	let CW = 800;
	let CH = 800;

	function resize(canvas) {
	CW = CH = 0.9 * Math.min(document.body.clientWidth, document.body.clientHeight);
	canvas.width = CW;
	canvas.height = CH;
	}

	function clear(ctx) {
	ctx.save();
	ctx.translate(0, 0);
	ctx.clearRect(0, 0, CW, CH);
	ctx.fillStyle = 'black';
	ctx.fillRect(0, 0, CW, CH);
	ctx.restore();
	}

	function drawOndulator(ctx, color, width, radius, nodes, state, rotation) {
	ctx.save();

	const sliceR = TAU / nodes;
	const stepR = sliceR / RR;
	const k = state * radius * Math.sin(sliceR / 2);

	ctx.translate(CW/2, CH/2);
	ctx.rotate(rotation);

	ctx.lineWidth = width;
	ctx.strokeStyle = color;

	for (let i = 0; i < nodes; ++i) {
	ctx.beginPath();
	ctx.moveTo(0, radius);

	for (let j = 0; j < RR + 2; ++j) {
	const r = radius + Math.pow(-1, i) * k * Math.sin(PI * j / RR);
	const x = r * Math.sin(j * stepR);
	const y = r * Math.cos(j * stepR);

	ctx.lineTo(x, y);
	}

	ctx.stroke();
	ctx.rotate(sliceR);
	}

	ctx.restore();
	}

	function main() {
	const canvas = document.createElement('canvas');
	document.body.appendChild(canvas);
	document.body.style.margin = '0px';
	document.body.style.display = 'flex';
	document.body.style.alignItems = 'center';
	document.body.style.justifyContent = 'center';

	const ctx = canvas.getContext('2d');

	const modes = 2;
	let mode = 0;

	canvas.addEventListener('click', () => {
	mode = (mode + 1) % modes;
	});

	function loop(t) {
	clear(ctx);
	ctx.globalCompositeOperation = 'lighten';

	switch (mode) {
	case 0:
	drawOndulator(ctx, 'rgba(255, 255, 255, 1)', 0.08 * CW / 2, 0.75 * CW / 2, 12, 0.5 * +Math.sin(t / 500), t/2500);
	drawOndulator(ctx, 'rgba(255, 255, 255, 1)', 0.08 * CW / 2, 0.75 * CW / 2, 12, 0.5 * -Math.sin(t / 500), t/2500);
	break;
	case 1:
	drawOndulator(ctx, 'rgba(255, 0, 0, 1)', 0.1 * CW / 2, 0.75 * CW / 2, 12, 0.5 * +Math.sin(t / 500), t/2500);
	drawOndulator(ctx, 'rgba(0, 255, 255, 1)', 0.1 * CW / 2, 0.75 * CW / 2, 12, 0.5 * -Math.cos(t / 500), t/2500);
	drawOndulator(ctx, 'rgba(0, 255, 0, 1)', 0.1 * CW / 2, 0.75 * CW / 2, 12, 0.5 * +Math.cos(t / 500), t/2500);
	break;
	}

	requestAnimationFrame(loop);
	}

	resize(canvas);
	requestAnimationFrame(loop);
	}

	window.addEventListener('load', main);
	</script>
	</head>
	<body style="background-color: black">

	</body>
	</html>