Pen Settings

HTML

About HTML Preprocessors

HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

Learn more · Versions

Adding Classes

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. So you don't have access to higher-up elements like the <html> tag. If you want to add classes there that can affect the whole document, this is the place to do it.

About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

!
Insecure Resource

The resource you are linking to is using the 'http' protocol, which may not work when the browser is using https.

CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

Learn more · Versions

CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

Powered by Algolia
About External Resources

You can apply CSS to your Pen from any stylesheet on the web. Just put a URL to it here and we'll apply it, in the order you have them, before the CSS in the Pen itself.

You can also link to another Pen here (use the .css URL Extension) and we'll pull the CSS from that Pen and include it. If it's using a matching preprocessor, use the appropriate URL Extension and we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

Learn more · Versions

Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

Powered by Algolia
About External Resources

You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.

If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.

You can also link to another Pen here, and we'll pull the JavaScript from that Pen and include it. If it's using a matching preprocessor, we'll combine the code before preprocessing, so you can use the linked Pen as a true dependency.

Learn more

+ add another resource

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Powered by Algolia
About Packages

Using packages here is powered by esm.sh, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ESM usage.

All packages are different, so refer to their docs for how they work.

If you're using React / ReactDOM, make sure to turn on Babel for the JSX processing.

Behavior

Auto Save

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML 

              
                <head>
     <link rel='stylesheet' href="harmonograph-style.css">

</head>


<html>

    <body id='main' onload="init()">

        
        <canvas id='canvas' class='' height="1080" width="1080"></canvas>
        
    
            <div class="controls">
			<button type="button" id="pauseBtn" onmouseup="this.blur();">Pause</button>
            <button type="button" id='resetBtn' onmouseup="this.blur();">Reset</button>
            <button id='spdBtn' onmouseup="this.blur();">speed</button>
              <div id="spf">256x</div>
		</div>
            
    <form class='center' name='anim_input' id='animInput' >
        
<div class='flex_container'>
        <div class='flex_col'>
                        <h3>Pendulum 1 Settings:</h3>
            <div class='flex_row'>
                <div class='flex_col'>
                    <input type="text" name='amp_x1' id='amp_x1' value=100 tabindex="1"></input>  
                    <label for='amp_x1' id='amp_x1_lbl'><p>Amplitude X</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='amp_y1' id='amp_y1' value=100 tabindex="2"></input>  
                    <label for='amp_y1' id='amp_y1_lbl'><p>Amplitude Y</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='phase_x1' id='phase_x1' value=90></input>  
                    <label for='phase_x1' id='phase_x1_lbl'><p>Phase X</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='phase_y1' id='phase_y1' value=0></input>  
                    <label for='phase_y1' id='phase_y1_lbl'><p>Phase Y</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='damp1' id='damp1' value=0></input>  
                    <label for='phase_x1' id='phase_x1_lbl'><p>Dampening</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='freq1' id='freq1' value=3  tabindex="7"></input>  
                    <label for='freq1' id='freq1_lbl'><p>Frequency</p></label>
                </div>
				<div class='flex_col'>
                    <input type="text" name='microtn1' id='microtn1' value=0.01  tabindex="10"></input>  
                    <label for='microtn1' id='microtn1_lbl'><p>Micro Tuning 1</p></label>
                </div>
			</div>
        </div>
</div>
<div class='flex_container'>
        <div class='flex_col'>
                        <h3>Pendulum 2 Settings:</h3>
            <div class='flex_row'>
                <div class='flex_col'>
                    <input type="text" name='amp_x2' id='amp_x2' value=100 tabindex="3"></input>  
                    <label for='amp_x2' id='amp_x2_lbl'><p>Amplitude X</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='amp_y2' id='amp_y2' value=100 tabindex="4"></input>  
                    <label for='amp_y2' id='amp_y2_lbl'><p>Amplitude Y</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='phase_x2' id='phase_x2' value=0></input>  
                    <label for='phase_x2' id='phase_x2_lbl'><p>Phase X</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='phase_y2' id='phase_y2' value=90></input>  
                    <label for='phase_y2' id='phase_y2_lbl'><p>Phase Y</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='damp2' id='damp2' value=0></input>  
                    <label for='damp2' id='damp2_lbl'><p>Dampening</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='freq2' id='freq2' value=2  tabindex="8"></input>  
                    <label for='freq2' id='freq2_lbl'><p>Frequency</p></label>
                </div>
				<div class='flex_col'>
                    <input type="text" name='microtn2' id='microtn2' value=0.02  tabindex="11"></input>  
                    <label for='microtn2' id='microtn2_lbl'><p>Micro Tuning 2</p></label>
                </div>
            </div>
        </div>
</div>
<div class='flex_container'>
        <div class='flex_col'>
                        <h3>Pendulum 3 Settings:</h3>
            <div class='flex_row'>
                <div class='flex_col'>
                    <input type="text" name='amp_x3' id='amp_x3' value=50 tabindex="5"></input>  
                    <label for='amp_x3' id='amp_x3_lbl'><p>Amplitude X</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='amp_y3' id='amp_y3' value=-50 tabindex="6"></input>  
                    <label for='amp_y3' id='amp_y3_lbl'><p>Amplitude Y</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='phase_x3' id='phase_x3' value=-90></input>  
                    <label for='phase_x3' id='phase_x3_lbl'><p>Phase X</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='phase_y3' id='phase_y3' value=0></input>  
                    <label for='phase_y3' id='phase_y3_lbl'><p>Phase Y</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='damp3' id='damp3' value=0></input>  
                    <label for='damp3' id='damp3_lbl'><p>Dampening</p></label>
                </div>
                <div class='flex_col'>
                    <input type="text" name='freq3' id='freq3' value=3  tabindex="9"></input>  
                    <label for='freq3' id='freq3_lbl'><p>Frequency</p></label>
                </div>
				<div class='flex_col'>
                    <input type="text" name='microtn3' id='microtn3' value=-0.01  tabindex="12"></input>  
                    <label for='microtn3' id='microtn3_lbl'><p>Micro Tuning 3</p></label>
                </div>
            </div>
        </div>
</div>
<div class='flex_container'>
	<div class='flex_col'>
            	<fieldset id='pattern_clr'>
					<label id='pattern_color' for='pattern_color'>Color?</label>
    	<div class='flex_row'>
					<div class='flex_col'>
						<input type='radio' name='pattern_color' id='red' value='red'/><p>Red</p>
					</div>
					<div class='flex_col'>
						<input type='radio' name='pattern_color' id='blue' value='blue'/><p>Blue</p>
					</div>
					<div class='flex_col'>
						<input type='radio' name='pattern_color' id='green' value='green'/><p>Green</p>
					</div>
					<div class='flex_col'>
						<input type='radio' name='pattern_color' id='orange' value='orange'/><p>Orange</p>
					</div>
					<div class='flex_col'>
						<input type='radio' name='pattern_color' id='purple' value='purple'/><p>Purple</p>
					</div>
            	</fieldset>      
		</div>

		

	<div class='flex_col'>
            	<fieldset id='pattern'>
					<label id='pattern_amount' for='pattern_amount'>How Much Pattern?</label>
            <div class='flex_row'>
					<div class='flex_col'>
						<input type='radio' name='pattern_amount' id='full' value='full' /><p>Full</p>
					</div>

					<div class='flex_col'>
						<input type='radio' name='pattern_amount' id='half' value='half'/><p>Half</p>
					</div>
					<div class='flex_col'>
						<input type='radio' name='pattern_amount' id='third' value='third'/><p>Third</p>
					</div>
            	</fieldset>
	</div>
			</div>
      	</div>
		<div class='flex_row'>
						<input class='submit_button' type="button" name='sbmtBtn' value="GO!" onclick="btnGetFormClick()">
		</div>       

		</div>
          
</form>
<!--        <script src='harmonograph-script.js'></script>-->
<div id='music_cheatsheet'>
  <h2>
    Some Musical Ratios
  </h2>
<h3>
Fifth is 3:2
<br>
Fourth is 4:3
<br>
Major sixth is 5:3
<br>
Major third is 5:4
<br>
Perfect eleventh is 8:3
<br>
Seventh-limit jazz tuning is 7:3
</h3>
</div>
!

CSS 

              
                
html {
  font-family: Helvetica, Arial, sans-serif;
  font-size: 80%;
    margin: 0;
    padding: 0;
}

body {
    margin: 0;
    padding: 0;
    overflow: auto;
    background-color: #000;
}

.center{
  position: absolute;
  top: 46%;
  left: 50%;
  transform: translate(-50%, -50%);
}

canvas {
/* background must be HEX color, otherwise FileSaver.js will render it with
   a white background */
    background: #000;
    position: absolute;
/* top: 75% looks good on a larger screen, when browser is at 100% zoom */
/*    top: 75%;*/
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    z-index: -1;
}

.controls {
    position: absolute;
    top: 3%;
    left: 3%;
    z-index: 1;
}

button,#spf {
    opacity: 0.5;
  display: inline-block;
  border-radius: 3px;
  border: 2px solid;
  font-size: 0.9rem;
  padding: 0.4rem 0.8em;
  background: rgba(0,0,0,0);
/*  border-bottom: 1px solid #498b50;*/
  color: white;
  -webkit-font-smoothing: antialiased;
  font-weight: bold;
  margin: 0 0.25rem;
  text-align: center;
  transition: 0.5s;
}

button:hover {
  opacity: 0.75;
background: rgba(224, 232, 255, 0.78);
    color: #000;
    border-color: white;
  cursor: pointer;
}

button:active {
  opacity: 1;
  box-shadow: 0 -3px 10px rgba(0, 0, 0, 0.1) inset;
}

.fadeaway {
    opacity: 0;
}

#ratio_col {
    opacity: 0.1;
    transition-duration: 1s;
}

input[type='radio'] {
    border: 0px;
    width: auto;
    height: 1.2em;
	margin-top: 7px;
}
input {
    height: 3.0em;
    width: 3.0em;
    font-size: 1.0em;
    padding: 0;
    text-align: center;
/*    display: block;*/
    border: none;
    border-radius: 50%;
    opacity: .65;
    color: #3e3e3e;
}

form {
/*    opacity: 0.65;*/
    color: rgba(255, 255, 255, 0.85);
    min-width: 650px;
    margin: 0 auto;
    border-radius: 4em;
    padding: 0.0em;
  	padding-bottom: 1em;
    background-color: rgba(87, 87, 87, 0.65);
    line-height: 1.1em;
    transition: 1s;
}

legend {
    text-align: center;
}

fieldset input {
    margin: 1em auto 0.2em auto;
}

legend + input {
    margin: 0.1em auto 0.75em auto;
}

input + p {
margin-top: 2px;
}

label {
    padding: 0;
    text-align: center;
    display: block;
    margin: 1em auto 0 auto;
}

fieldset {
display: -webkit-flex;
    display: flex;
    border: none;
/*    text-align: center;*/
/*    width: 100%;*/
}

.flex_container {
display: -webkit-flex;
    display: flex;
    -webkit-justify-content: center;
    justify-content: center;
    flex-direction: row;
	align-items: center;
    margin: 0 .1em;
/*    width: 100%;*/    
}

.flex_row {
display: -webkit-flex;
    display: flex;
    -webkit-justify-content: space-around;
    justify-content: space-around;
    flex-direction:row;
	width: auto;
}

.flex_col {
    flex-direction: column;
     -webkit-justify-content: space-between;
    justify-content: space-between;
    text-align: center;
	align-items: center;
	margin: 0 10px;
}

#pattern_color,#pattern_amount {
	font-weight: bold;
	font-size: 1.2em;
}

#epi,#hypo,#mod_yes,#mod_no,#ellip_Big_ratio,#ellip_sml_ratio {
    margin: 0 0.5em;
}

.flex_box {
display: -webkit-flex;
    display: flex;
    -webkit-justify-content: center;
    justify-content: center;
    flex-direction: row;
/*    width: 30%;*/
/*    background-color: lightgrey;*/
}

#firstrow,#secondrow,#thirdrow,#fourthrow {
display: -webkit-flex;
    display: flex;
    -webkit-justify-content: center;
    justify-content: center;
    width: 100%;
/*    background-color: lightgrey;*/
}

#fourthrow, #fifthrow {
    display: flex;
    flex-wrap: wrap;
    flex-direction: row;
    justify-content:flex-start;
    padding-left: 2.6em;
}

.row1 {
/*    float: left;*/
    margin: 0 0.6em;
    width: 22.7%;
}
.row2,.row3,.row4 {
    text-align: center;
    margin: 0 0.6em;
    width: 22%;
}

.row4,.row5 {
    display: flex;
    flex-wrap: nowrap;
    text-align: left;
    margin-top: 0.5em;
    width: 100%;
        align-content:flex-end;
}

#row5_first {
    margin-top: 3em;
}

#fourthrow_first_col,#fifthrow_first_col {
    display: flex;
    flex-direction: column;
    margin-right: 2em;
}

fourthrow_second_col,#fifthrow_second_col {
    display: -webkit-flex;
   display: flex;
   -webkit-flex-direction: column /* works with row or column */
   flex-direction: column;
   -webkit-align-items: center;
   align-items: flex-start;
   -webkit-justify-content: center;
   justify-content: center;
}
/*
* [type="color"] {
    border-radius: 0;
        border: none;
    background-color: none;
}
*/
#colorpicker {
/*
    width: 2em;
    height: 2em;
*/
    margin-top: 0.5em;
    border-radius: 0;
        border: none;
    background: none;
}

#formleft {
    width: 40%;
    padding-left: 3em;
    float: left;
}
#formright {
    display: none;
    width: 50%;
    float: right;
}

#formlast {
/*    overflow: auto;*/
    
/*    display: block;*/
/*    width: 60%;*/
    margin: 2em auto;

}

.submit_button {
    float: none;
    height: 5.25em;
    width: 5.25em;
    font-size: 1.5em;
    font-weight: bold;
    color: #313131;
    padding: 0;
    text-align: center;
    border: none;
    border-radius: 50%;
}

[type='range'] {
    height: 1em;
    width: 280px;
    margin: 4px 10px 0 0;
    padding: 0;
        align-content: center;

}

#green_value,#blue_value,#opacity_value {
    margin-top: 16px;
}

#outputRed {
    margin-top: 5px;
}

#outputBlue,#outputGreen,#outputOpacity {
    margin-top: 17px;
}

#outputRed,#outputGreen,#outputBlue,#outputHorzScale,#outputVertScale,#outputOpacity { 
    display: inline-table;
    width: 105px;
  color: white;
    opacity: 0.75;
    padding: 0 1em;
  border-radius: 10px;
  font: bold 15px/20px;
}

/*
output:after { 
  content: "";
  position: absolute; 
  width: 0;
  height: 0;
  border-top: 10px solid #999999;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  top: 100%;
  left: 50%;
  margin-left: -5px;
  margin-top: -1px;
}
*/

#colorSwatch {
    margin-top: 0.8em;
    height: 112px;
    width: 138px;
    border-color: aliceblue;
    background-color: rgb(255,107,0,0.40);
    transition: 0.5s;
}

input.error {background-color: #671008;}

#music_cheatsheet {
display: block;
position: absolute;
top: 10%;
left: 3%;
color: hsl(0, 0%, 25%);
}

.flex-container-col,.flex-container-row {
		  padding: 0;
		  margin: 0;
		  list-style: none;
		  display: -webkit-box;
		  display: -moz-box;
		  display: -ms-flexbox;
		  display: -webkit-flex;
		  display: flex;
		  -webkit-flex-flow: column wrap;
		  justify-content: space-around;
}

.flex-container-row {
		  -webkit-flex-flow: row wrap;
}

.flex-item {
		  background: tomato;
		  padding: 5px;
		  width: 200px;
/*		  height: 150px;*/
		  margin-top: 10px;
		  color: greenyellow;
		  font-weight: bold;
		  font-size: 1em;
		  text-align: center;
}

.color-selector {
		width: 40%;
}

.flex-container-row .flex-item {
		width: 46px;
		background-color: purple;
}
!

JS 

              
                //  Some variables, and the step() function, based on Andy Giger's virtual harmonograph:
//  andygiger.com/science/harmonograph/index.html
//  Although I didn't use Mr. Giger's equations, I learned a lot by studying them,
//  and am eternally grateful to him for posting his work

//  The equations I used are from the Wikipedia entry on Harmongraphs:
//  https://en.wikipedia.org/wiki/Harmonograph#Computer-generated_harmonograph_figure

//  BASIC VARIABLES  //

var theta = 0;
// frequency   HOW FAR APART THE DOTS ARE, SMALLER NUMBERS = CLOSER
var fd;
var f1;
var f2;
var f3;
var f4;
var f5;
var f6;

//  micro tuning
var mt1;
var mt2;
var mt3;

// phase
var p1;
var p2;
var p3;
var p4;
var p5;
var p6;

var ad;
var a1; // Amplitude   //   CONTROLS THE OVERALL SIZE, LARGER NUMBERS = BIGGER
var a2;
var a3;
var a4;
var a5;
var a6;

var d1; // dampening; 0 = pendulum won't naturally stop swinging due to gravity
var d2;
var d3;
var d4;
var d5;
var d6;

// Canvas
var canvas;

// 2d Drawing Context.
var ctx;

var centerX, centerY;
var rot_increment;
var revo_increment_multiplier;
var userInputForm;
var s = 256;
var t = 0.0;
var dt = 0.001;
var intId;
var ns, setns = 100000;
var revolutions;

var userInputForm = document.anim_input;

var full_pattern = 314000;
var half_pattern = 157000; 
var third_pattern = 104666;

var pattern_color;
var requestID;
var animation_is_running;

//  END BASIC VARIABLES  //

//  LETS GET THIS PARTY STARTED

function init() {
  window.clearInterval(intId);
  intId = null;
  canvas = document.getElementById('canvas');
  ctx = canvas.getContext('2d');
  ctx.globalCompositeOperation = 'source-over';
  centerX = canvas.width / 2;
  centerY = canvas.height / 2;
  ctx.setTransform(1, 0, 0, 1, 0, 0);
  ctx.rotate(0);
  ctx.translate(0, 0);

  ctx.moveTo(0, 0);
  ctx.fillStyle = 'rgba(0,0,0,1)';
  ctx.fillRect(0, 0, canvas.width, canvas.height);
  ctx.rotate(theta);

  ctx.fillStyle = pattern_color;
  ctx.translate(centerX, centerY);

  userInputForm = document.anim_input;
  userInputForm.sbmtBtn.addEventListener('click', btnGetFormClick);
  
  fd = 0.001;
  
  mt1 = parseFloat(document.getElementById('microtn1').value);
  mt2 = parseFloat(document.getElementById('microtn2').value);
  mt3 = parseFloat(document.getElementById('microtn3').value);

  f1 = (parseFloat(document.getElementById('freq1').value) + mt1) * fd;
  f2 = f1;
  f3 = (parseFloat(document.getElementById('freq2').value) + mt2) * fd;
  f4 = f3;
  f5 = (parseFloat(document.getElementById('freq3').value) + mt3) * fd;
  f6 = f5;

  p1 = parseInt(document.getElementById('phase_x1').value) / 180 * Math.PI;
  p2 = parseInt(document.getElementById('phase_y1').value) / 180 * Math.PI;
  p3 = parseInt(document.getElementById('phase_x2').value) / 180 * Math.PI;
  p4 = parseInt(document.getElementById('phase_y2').value) / 180 * Math.PI;
  p5 = parseInt(document.getElementById('phase_x3').value) / 180 * Math.PI;
  p6 = parseInt(document.getElementById('phase_y3').value) / 180 * Math.PI;

  ad = 2;
  a1 = document.getElementById('amp_x1').value * ad;
  a2 = document.getElementById('amp_y1').value * ad;
  a3 = document.getElementById('amp_x2').value * ad;
  a4 = document.getElementById('amp_y2').value * ad;
  a5 = document.getElementById('amp_x3').value * ad;
  a6 = document.getElementById('amp_y3').value * ad;

  willbe_d1 = document.getElementById('damp1').value;
  willbe_d3 = document.getElementById('damp2').value;
  willbe_d5 = document.getElementById('damp3').value;

  t = 0.0;
  ns = setns;
  revolutions = 0;
  rot_increment = 6;  //  I DON'T THINK I EVEN USE THIS
  revo_increment_multiplier = 1.0; //  OR THIS EITHER

  intId = window.setInterval(step, 1000 * dt);
}

function step() {
  for (var i = 0; i < s; ++i) {
    t += dt;
    drawFrame();
  }


  function drawFrame() {

    dt = 2;
    d1 = willbe_d1 / 1000000; // dampening
    d2 = d1;
    d3 = willbe_d3 / 1000000;
    d4 = d3;
    d5 = willbe_d5 / 1000000;
    d6 = d5;

    var x = a1 * Math.sin((t * f1) + p1) * Math.exp(-d1 * t) + a3 * Math.sin((t * f3) + p3) * Math.exp(-d3 * t) + a5 * Math.sin((t * f5) + p5) * Math.exp(-d5 * t);

    var y = a2 * Math.sin((t * f2) + p2) * Math.exp(-d2 * t) + a4 * Math.sin((t * f4) + p4) * Math.exp(-d4 * t) + a6 * Math.sin((t * f6) + p6) * Math.exp(-d6 * t);

    ctx.beginPath();
    ctx.rect(x, y, 2, 2);
    ctx.fill();
    revolutions += 1;

    if (revolutions == pattern_amount) {
      window.clearInterval(intId);
      intId = null;
    }
//   END OF DRAWFRAME FUNCTION
  }
};

window.onload = function() {
  document.getElementById('spdBtn').addEventListener('click', function(e) {
    s = s * 2;
    if (s > 1024) {
      s = 256;
    };
    document.getElementById('spf').innerHTML = s + "x";
    console.log('from inside the spdBtn function');

  });
  document.getElementById('resetBtn').addEventListener('click', formReset);
  document.getElementById('resetBtn').addEventListener('click', erase);
  document.getElementById('main').addEventListener('keyup', checkSubmit);

  revolutions = 0;

};

function btnGetFormClick(e) {

  revolutions = 0;

  console.log('from inside btnGetFormClick function = ');

  document.getElementById('animInput').setAttribute('class', 'center fadeaway');
  document.getElementById('main').removeEventListener('keyup', checkSubmit);
  document.getElementById('pauseBtn').addEventListener('click', pause);
  setPatternAmount();
  setColor();
  console.log('from inside btnGetFormClick function, pattern amount = ' + pattern_amount);

  init();
}

function setPatternAmount() {

  x = userInputForm.pattern_amount.value;

  switch (x) {
    case 'full':
      pattern_amount = 314000;
      break;
    case 'half':
      pattern_amount = 157000;
      break;
    case 'third':
      pattern_amount = 104666;
      break;
    default:
      pattern_amount = 314001;
      break;
  };
}

function setColor() {

  x = userInputForm.pattern_color.value;

  switch (x) {
    case 'red':
      pattern_color = 'rgba(255, 0, 0, 0.3)';
      break;
    case 'green':
      pattern_color = 'rgba(0, 255, 29, 0.3)';
      break;
    case 'blue':
      pattern_color = 'rgba(0, 177, 255, 0.3)';
      break;
    case 'orange':
      pattern_color = 'rgba(255, 128, 0, 0.3)';
      break;
    case 'purple':
      pattern_color = 'rgba(108, 0, 255, 0.3)';
      break;
    default:
      pattern_color = 'rgba(255, 157, 0, 0.3)';
      break;
  };

}

var checkSubmit = function(e) {
  e.preventDefault();

  console.log('checkSubmit function fired');

  if (e && e.keyCode == 13) {
    btnGetFormClick();
  }
}

var checkReset = function(e) {
  if (e && e.keyCode == 82) {
    console.log('checkReset triggered formReset function');
    formReset();
  }
}

function formReset() {
  window.clearInterval(intId);
  intId = null;
  document.getElementById('pauseBtn').removeEventListener('click', pause);
  erase();
}

function pause() {
  //intId = window.setInterval(step, 1000 * dt);

  console.log('from within the pause function');

  var stab = document.getElementById('pauseBtn');
  if (intId == null) {
    intId = window.setInterval(step, 1000 * dt);
    stab.innerHTML = 'Pause';
  } else {
    window.clearInterval(intId);
    intId = null;
    stab.innerHTML = 'Resume';
  }
}

document.getElementById('saveBtn').addEventListener('click', function(e) {

  canvas.toBlob(function(blob) {
    saveAs(blob, "pretty image.png");
  });
});

function erase() {

  console.log('from inside the erase function');

  ctx.setTransform(1, 0, 0, 1, 0, 0);
  ctx.rotate(0);
  ctx.translate(0, 0);

  ctx.moveTo(0, 0);

  revolutions = 0;

  centerX = canvas.width / 2;
  centerY = canvas.height / 2;

  theta = 0;
  revolutions = 0;
  s = 256;
  t = 0.0;
  dt = 0.001;
  ns = 100000;
  setns = 100000;

  ctx.clearRect(0, 0, canvas.width, canvas.height);
  ctx.fillStyle = 'rgb(0,0,0)';
  ctx.fillRect(0, 0, canvas.width, canvas.height);

  document.getElementById('spf').innerHTML = s + "x";

  document.getElementById('animInput').setAttribute('class', 'center');
  document.getElementById('main').addEventListener('keyup', checkSubmit);
}
!
999px

Console