css Audio - Active file-generic CSS - Active Generic - Active HTML - Active JS - Active SVG - Active Text - Active file-generic Video - Active header Love html icon-new-collection icon-person icon-team numbered-list123 pop-out spinner split-screen star tv

Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

You're using npm packages, so we've auto-selected Babel for you here, which we require to process imports and make it all work. If you need to use a different JavaScript preprocessor, remove the packages in the npm tab.

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.

+ add another resource

Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

⚠️ This feature can only be used by logged in users.

Code Indentation

     

Save Automatically?

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.

HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              
<!--   <div class="trigger"></div> -->
<!--   <article> -->
  
    <p>
      <a href="#" class="underline title">Underline</a>
    </p>
    <p class="text">
      <a href="#" class="underline">Testing descenders</a>
        <br>
      <a href="#" class="underline">to see g and y and p</a>
        <br>
      <a href="#" class="underline">with a nice underline</a>
        <br>
      <a href="#" class="underline">jump google quick yogurt</a>
        <br>
      <a href="#" class="underline">spanning multiple lines is still broken though...</a>
        <br>
    </p>
  
<!--   </article> -->
	
            
          
!
            
              .underline {
	position: relative;
}
.underline span {
  pointer-events: none;
}
.underline canvas {
  	pointer-events: auto;
	position: absolute;
	top: 0;
	left: 0;
	/*background-color: rgba(222, 222, 222, 0.1);*/
	/*z-index: -1;*/
	-moz-user-select: none; 
	-khtml-user-select: none; 
	-webkit-user-select: none; 
	-o-user-select: none; 
	cursor: pointer;
}

body {
  font-size: 24px;
  line-height: 36px;
  color: #212121;
  margin: 0 auto;
  width: 500px;
  padding: 0;
  -moz-osx-font-smoothing: grayscale;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
   }

a {
  text-decoration: none;
  color: #212121; }

p {
  font-family: "EB Garamond";
  margin-top: 24px; }

p.text a {
  font-size: 48px;
  line-height: 1.4em;
  font-style: italic; }

p a.title {
  font-size: 126px;
  line-height: 1.4em; }

p em {
  font-style: italic; }

p:empty {
  margin-top: 0px; }


            
          
!
            
              /* Universal Module Definition */
(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as a named AMD module.
    define('baselineRatio', [], function () {
      return (root.baselineRatio = factory());
    });
  } else if (typeof exports === 'object') {
    // Node. Does not work with strict CommonJS, but
    // only CommonJS-like enviroments that support module.exports,
    // like Node.
    module.exports = factory();
  } else {
    // Browser globals
    root.baselineRatio = factory();
  }
}(this, function () {
  var baselineRatio = function(elem) {
    // Get the baseline in the context of whatever element is passed in.
    elem = elem || document.body;

    // The container is a little defenseive.
    var container = document.createElement('div');
    container.style.display = "block";
    container.style.position = "absolute";
    container.style.bottom = "0";
    container.style.right = "0";
    container.style.width = "0px";
    container.style.height = "0px";
    container.style.margin = "0";
    container.style.padding = "0";
    container.style.visibility = "hidden";
    container.style.overflow = "hidden";

    // Intentionally unprotected style definition.
    var small = document.createElement('span');
    var large = document.createElement('span');

    // Large numbers help improve accuracy.
    small.style.fontSize = "0px";
    large.style.fontSize = "2000px";

    small.innerHTML = "X";
    large.innerHTML = "X";

    container.appendChild(small);
    container.appendChild(large);

    // Put the element in the DOM for a split second.
    elem.appendChild(container);
    var smalldims = small.getBoundingClientRect();
    var largedims = large.getBoundingClientRect();
    elem.removeChild(container);

    // Calculate where the baseline was, percentage-wise.
    var baselineposition = smalldims.top - largedims.top;
    var height = largedims.height;

    return 1 - (baselineposition / height);
  }

  return baselineRatio;
}));

/*!
 * classie v1.0.1
 * class helper functions
 * from bonzo https://github.com/ded/bonzo
 * MIT license
 * 
 * classie.has( elem, 'my-class' ) -> true/false
 * classie.add( elem, 'my-new-class' )
 * classie.remove( elem, 'my-unwanted-class' )
 * classie.toggle( elem, 'my-class' )
 */

/*jshint browser: true, strict: true, undef: true, unused: true */
/*global define: false, module: false */

( function( window ) {

'use strict';

// class helper functions from bonzo https://github.com/ded/bonzo

function classReg( className ) {
  return new RegExp("(^|\\s+)" + className + "(\\s+|$)");
}

// classList support for class management
// altho to be fair, the api sucks because it won't accept multiple classes at once
var hasClass, addClass, removeClass;

if ( 'classList' in document.documentElement ) {
  hasClass = function( elem, c ) {
    return elem.classList.contains( c );
  };
  addClass = function( elem, c ) {
    elem.classList.add( c );
  };
  removeClass = function( elem, c ) {
    elem.classList.remove( c );
  };
}
else {
  hasClass = function( elem, c ) {
    return classReg( c ).test( elem.className );
  };
  addClass = function( elem, c ) {
    if ( !hasClass( elem, c ) ) {
      elem.className = elem.className + ' ' + c;
    }
  };
  removeClass = function( elem, c ) {
    elem.className = elem.className.replace( classReg( c ), ' ' );
  };
}

function toggleClass( elem, c ) {
  var fn = hasClass( elem, c ) ? removeClass : addClass;
  fn( elem, c );
}

var classie = {
  // full names
  hasClass: hasClass,
  addClass: addClass,
  removeClass: removeClass,
  toggleClass: toggleClass,
  // short names
  has: hasClass,
  add: addClass,
  remove: removeClass,
  toggle: toggleClass
};

// transport
if ( typeof define === 'function' && define.amd ) {
  // AMD
  define( classie );
} else if ( typeof exports === 'object' ) {
  // CommonJS
  module.exports = classie;
} else {
  // browser global
  window.classie = classie;
}

})( window );

function MultipleUnderline(element, underlineStyles, elementStyles) {
    //ctor
    this.element = element;

    this.text = this.element.textContent;

    this.underlineStyles = underlineStyles;

    // this.elementStyles = getElementStyles(element);
    this.elementStyles = elementStyles;

    this.canvas = document.createElement("canvas");
    this.ctx = this.canvas.getContext('2d');


    this.ratio = window.devicePixelRatio;
        this.canvas.width = this.elementStyles.width*this.ratio;
        this.canvas.height = this.elementStyles.height*this.ratio;
        // this.canvas.height = this.canvas.clientHeight + this.elementStyles.lineHeight;
        this.canvas.style.left = this.elementStyles.canvasLeft + 'px';
        this.element.appendChild(this.canvas);
        this.canvas.style.width =  this.elementStyles.width + 'px';

        this.ctx.font = this.font = this.elementStyles.fontStyle + ' ' 
                        + multiplyValue(this.elementStyles.fontSize, this.ratio) + ' ' 
                        + this.elementStyles.fontFamily;

    this.multipleRedrawActive = false;
    if (is_chrome) {
        // chrome floor the lineheight when it is not a whole number
        // this.elementStyles.lineHeight = Math.floor(this.elementStyles.lineHeight * this.ratio);
        this.elementStyles.lineHeight = this.elementStyles.lineHeight * this.ratio;
    } else {
        this.elementStyles.lineHeight = this.elementStyles.lineHeight * this.ratio;
    }

    // determine the text-underline-width / strokeWidth
    var dotWidth = this.ctx.measureText('.')['width'];
    if (this.underlineStyles['text-underline-width'] == "auto") {
        // if set to auto, calculate the optimized width based on font
        this.strokeWidth = dotWidth/12;
    } else {
        //if set to px value, todo: other unit such as em?
        this.strokeWidth = this.underlineStyles['text-underline-width'];
        //get number value
        this.strokeWidth = parseFloat(this.strokeWidth)*this.ratio;
    }

    // determine the text-underline-position / underlinePosition
    // text-underline-position in ratio, todo: default and user set position ratio
    if (this.underlineStyles['text-underline-position'] == "auto") {
        // if set to auto, calculate the optimized width based on font
        this.underlinePosition = parseFloat(this.elementStyles.fontSize) * this.ratio 
                * ( 1 - this.elementStyles.baselinePositionRatio + 
                    this.elementStyles.baselinePositionRatio * 0.4)
                + this.strokeWidth/2;
    } else {
        //if set to ratio value, todo: other unit such as em, px?
        var userUnderlinePosition = parseFloat(this.underlineStyles['text-underline-position']);
        // console.log(userUnderlinePosition);
        this.underlinePosition = parseFloat(this.elementStyles.fontSize) * this.ratio * 
                ( 1 - this.elementStyles.baselinePositionRatio + 
                    this.elementStyles.baselinePositionRatio * userUnderlinePosition)
                + this.strokeWidth/2;
    }


    var adjustValue = optimalStrokeWidthPos(this.strokeWidth, this.underlinePosition);
    this.strokeWidth = adjustValue.strokeWidth;
    this.underlinePosition = adjustValue.posY;

    this.lines = [];
    this.myStrings = [];

    var words = this.text.match(/[^\s-]+-?\s?/g);
    var line = '';

    var linePositionY = 0;
    var firstLineCount = 0;
    for (var n = 0; n < words.length; n++) {
        // add the whitespace after getting the width measurement
        if (words[n].match(/\s+$/)) {
            // the last character of words[n] is whitespace
            var newWord = words[n].replace(/\s+$/, '');
            var testLine = line + newWord;
            var testLineMetrics = this.ctx.measureText(testLine);
            var testLineWidth = testLineMetrics.width;
            testLine = testLine + ' ';
        } else {
            var testLine = line + words[n];
            var testLineMetrics = this.ctx.measureText(testLine);
            var testLineWidth = testLineMetrics.width;
        }

        if (!firstLineCount) {
            //the first line, should consider startingPointX
            if (testLineWidth + this.elementStyles.textIndent * this.ratio > this.elementStyles.parentWidth * this.ratio && n > 0) {
                //  draw the underline
                if (line.match(/\s+$/)) {
                    // the last character of line is whitespace               
                    var lineMetrics = this.ctx.measureText(line.replace(/\s+$/, ''));
                    var lineWidth = lineMetrics.width;
                } else {
                    var lineMetrics = this.ctx.measureText(line);
                    var lineWidth = lineMetrics.width;
                }

                var tempLine = {
                    lineText: line,
                    lineTextIndent: this.elementStyles.textIndent * this.ratio - 0.2,
                    linePositionY: linePositionY,
                    lineMeasureWidth: lineWidth
                }
                this.lines.push(tempLine)

                line = words[n];
                linePositionY += this.elementStyles.lineHeight;
                firstLineCount++;
            } else {
                line = testLine;
            }
        } else {
            if (testLineWidth > this.elementStyles.parentWidth * this.ratio && n > 0) {
                //  draw the underline
                if (line.match(/\s+$/)) {
                    // the last character of line is whitespace               
                    var lineMetrics = this.ctx.measureText(line.replace(/\s+$/, ''));
                    var lineWidth = lineMetrics.width;
                } else {
                    var lineMetrics = this.ctx.measureText(line);
                    var lineWidth = lineMetrics.width;
                }

                var tempLine = {
                    lineText: line,
                    lineTextIndent: -0.2,
                    linePositionY: linePositionY,
                    lineMeasureWidth: lineWidth
                }
                this.lines.push(tempLine);

                line = words[n];
                linePositionY += this.elementStyles.lineHeight;
            } else {
                line = testLine;
            }
        }
    }
    // draw the last line
    //  draw the underline
    if (line.match(/\s+$/)) {
        // the last character of line is whitespace               
        var lineMetrics = this.ctx.measureText(line.replace(/\s+$/, ''));
        var lineWidth = lineMetrics.width;
    } else {
        var lineMetrics = this.ctx.measureText(line);
        var lineWidth = lineMetrics.width;
    }

    var tempLine = {
        lineText: line,
        lineTextIndent: -0.2,
        linePositionY: linePositionY,
        lineMeasureWidth: lineWidth
    }
    this.lines.push(tempLine);
    for(var i = 0; i < this.lines.length; i++) {
        var tempLine = this.lines[i];
        var myString = new GuitarString(
                this.ctx, 
                new Point(tempLine.lineTextIndent, tempLine.linePositionY + this.underlinePosition), 
                new Point(tempLine.lineTextIndent + tempLine.lineMeasureWidth, tempLine.linePositionY + this.underlinePosition), 
                this.strokeWidth, this.underlineStyles['text-underline-color'], this.ratio);
        this.myStrings.push(myString);
    }

    this.drawUnderline();
    this.drawHoles();

}

MultipleUnderline.prototype.drawUnderline = function(){
    // draw the underline
    for(var i = 0; i < this.myStrings.length; i++) {
        var tempString = this.myStrings[i];
        // tempString.clear();
            tempString.update();
            tempString.draw();
    }

};


MultipleUnderline.prototype.drawHoles = function(){
    // draw the font stroke
    for(var i = 0; i < this.lines.length; i++) {
        var tempLine = this.lines[i];

        this.ctx.globalCompositeOperation = "destination-out";
        this.ctx.font = this.font;

        this.ctx.fillStyle = 'green';
        this.ctx.textBaseline = 'top';
        this.ctx.fillText(tempLine.lineText, tempLine.lineTextIndent, tempLine.linePositionY);

        this.ctx.lineWidth = 2*this.ratio + this.strokeWidth*3.6;
        this.ctx.strokeStyle = 'blue';
        this.ctx.strokeText(tempLine.lineText, tempLine.lineTextIndent, tempLine.linePositionY);

    }
}

MultipleUnderline.prototype.clear = function(){
    // clear
    var lastMultipleRedrawActive = this.multipleRedrawActive;
    this.multipleRedrawActive = false;
    for(var i = 0; i < this.myStrings.length; i++) {
        var tempString = this.myStrings[i];
        // this.myString.clear();
        // console.log(tempString.redrawActive);
        if(tempString.redrawActive) {
            this.multipleRedrawActive = true;
        }
    }
    // console.log(this.multipleRedrawActive);
    if (this.multipleRedrawActive) {
        console.log('clear now!')
        this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
    }
    // if (!lastMultipleRedrawActive && this.multipleRedrawActive) {
    //     for(var i = 0; i < this.myStrings.length; i++) {
    //         var tempString = this.myStrings[i];
    //         tempString.drawLine();
    //     }
    // }

};

MultipleUnderline.prototype.update = function(){
    //update
};


MultipleUnderline.prototype.draw = function(){
    // draw
    if (this.multipleRedrawActive) {
        this.drawUnderline();
        this.drawHoles();
    }
};

function MultipleUnderline(element, underlineStyles, elementStyles) {
    //ctor
    this.element = element;

    this.text = this.element.textContent;

    this.underlineStyles = underlineStyles;

    // this.elementStyles = getElementStyles(element);
    this.elementStyles = elementStyles;

    this.canvas = document.createElement("canvas");
        this.canvas.width = this.elementStyles.width;
        this.canvas.height = this.elementStyles.height;
        this.canvas.style.left = this.elementStyles.canvasLeft + 'px';
        this.element.appendChild(this.canvas);
        this.canvas.width = this.canvas.clientWidth;
        this.canvas.height = this.canvas.clientHeight + this.elementStyles.lineHeight;

    this.ctx = this.canvas.getContext('2d');
    this.ctx.font = this.font = this.elementStyles.fontStyle + ' ' + this.elementStyles.fontSize + ' ' + this.elementStyles.fontFamily;

    this.multipleRedrawActive = false;
    if (is_chrome) {
        // chrome floor the lineheight when it is not a whole number
        this.elementStyles.lineHeight = Math.floor(this.elementStyles.lineHeight);
    }


    // determine the text-underline-width / strokeWidth
    this.dotWidth = this.ctx.measureText('.')['width'];
    if (this.underlineStyles['text-underline-width'] == "auto") {
        // if set to auto, calculate the optimized width based on font
        if (this.dotWidth / 6 <= 2) {
            this.strokeWidth = Math.round(this.dotWidth / 3) / 2;
        } else {
            this.strokeWidth = Math.round(this.dotWidth / 6);
        }
    } else {
        //if set to px value
        this.strokeWidth = this.underlineStyles['text-underline-width'];
        //get number value
        this.strokeWidth = parseFloat(this.strokeWidth);
    }

    // determine the text-underline-position / underlinePosition
    // text-underline-position in ratio
    this.underlinePosition = parseFloat(this.elementStyles.fontSize) * 0.89;
    if (this.strokeWidth <= 1 || (this.strokeWidth % 2 && this.strokeWidth > 2)) {
        this.underlinePosition = Math.round(this.underlinePosition - 0.5) + 0.5;
    } else {
        this.underlinePosition = Math.round(this.underlinePosition);
    }

    this.lines = [];
    this.myStrings = [];

    var words = this.text.match(/[^\s-]+-?\s?/g);
    var line = '';

    var linePositionY = 0;
    var firstLineCount = 0;
    for (var n = 0; n < words.length; n++) {
        // add the whitespace after getting the width measurement
        if (words[n].match(/\s+$/)) {
            // the last character of words[n] is whitespace
            var newWord = words[n].replace(/\s+$/, '');
            var testLine = line + newWord;
            var testLineMetrics = this.ctx.measureText(testLine);
            var testLineWidth = testLineMetrics.width;
            testLine = testLine + ' ';
        } else {
            var testLine = line + words[n];
            var testLineMetrics = this.ctx.measureText(testLine);
            var testLineWidth = testLineMetrics.width;
        }

        if (!firstLineCount) {
            //the first line, should consider startingPointX
            if (testLineWidth + this.elementStyles.textIndent > this.elementStyles.parentWidth && n > 0) {
                //  draw the underline
                if (line.match(/\s+$/)) {
                    // the last character of line is whitespace               
                    var lineMetrics = this.ctx.measureText(line.replace(/\s+$/, ''));
                    var lineWidth = lineMetrics.width;
                } else {
                    var lineMetrics = this.ctx.measureText(line);
                    var lineWidth = lineMetrics.width;
                }

                var tempLine = {
                    lineText: line,
                    lineTextIndent: this.elementStyles.textIndent,
                    linePositionY: linePositionY,
                    lineMeasureWidth: lineWidth
                }
                this.lines.push(tempLine)

                line = words[n];
                linePositionY += this.elementStyles.lineHeight;
                firstLineCount++;
            } else {
                line = testLine;
            }
        } else {
            if (testLineWidth > this.elementStyles.parentWidth && n > 0) {
                //  draw the underline
                if (line.match(/\s+$/)) {
                    // the last character of line is whitespace               
                    var lineMetrics = this.ctx.measureText(line.replace(/\s+$/, ''));
                    var lineWidth = lineMetrics.width;
                } else {
                    var lineMetrics = this.ctx.measureText(line);
                    var lineWidth = lineMetrics.width;
                }

                var tempLine = {
                    lineText: line,
                    lineTextIndent: 0,
                    linePositionY: linePositionY,
                    lineMeasureWidth: lineWidth
                }
                this.lines.push(tempLine);

                line = words[n];
                linePositionY += this.elementStyles.lineHeight;
            } else {
                line = testLine;
            }
        }
    }
    // draw the last line
    //  draw the underline
    if (line.match(/\s+$/)) {
        // the last character of line is whitespace               
        var lineMetrics = this.ctx.measureText(line.replace(/\s+$/, ''));
        var lineWidth = lineMetrics.width;
    } else {
        var lineMetrics = this.ctx.measureText(line);
        var lineWidth = lineMetrics.width;
    }

    var tempLine = {
        lineText: line,
        lineTextIndent: 0,
        linePositionY: linePositionY,
        lineMeasureWidth: lineWidth
    }
    this.lines.push(tempLine);



    for(var i = 0; i < this.lines.length; i++) {
        var tempLine = this.lines[i];
        var myString = new GuitarString(
                this.ctx, 
                new Point(tempLine.lineTextIndent, tempLine.linePositionY + this.underlinePosition), 
                new Point(tempLine.lineTextIndent + tempLine.lineMeasureWidth, tempLine.linePositionY + this.underlinePosition), 
                this.strokeWidth, this.underlineStyles['text-underline-color'], 1);
        this.myStrings.push(myString);
    }

    this.drawUnderline();
    this.drawHoles();

}


MultipleUnderline.prototype.clear = function(){
    // clear
    var lastMultipleRedrawActive = this.multipleRedrawActive;
    this.multipleRedrawActive = false;
    for(var i = 0; i < this.myStrings.length; i++) {
        var tempString = this.myStrings[i];
        // this.myString.clear();
        // console.log(tempString.redrawActive);
        if(tempString.redrawActive) {
            this.multipleRedrawActive = true;
        }
    }
    // console.log(this.multipleRedrawActive);
    if (this.multipleRedrawActive) {
        console.log('clear now!')
        this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
    }
    // if (!lastMultipleRedrawActive && this.multipleRedrawActive) {
    //     for(var i = 0; i < this.myStrings.length; i++) {
    //         var tempString = this.myStrings[i];
    //         tempString.drawLine();
    //     }
    // }

};

MultipleUnderline.prototype.update = function(){
    //update
};


MultipleUnderline.prototype.draw = function(){
    // draw
    if (this.multipleRedrawActive) {
        this.drawUnderline();
        this.drawHoles();
    }
};


MultipleUnderline.prototype.drawUnderline = function(){
    // draw the underline
    for(var i = 0; i < this.myStrings.length; i++) {
        var tempString = this.myStrings[i];
        // tempString.clear();
            tempString.update();
            tempString.draw();
    }

};


MultipleUnderline.prototype.drawHoles = function(){
    // draw the font stroke
    for(var i = 0; i < this.lines.length; i++) {
        var tempLine = this.lines[i];

        this.ctx.globalCompositeOperation = "destination-out";
        this.ctx.font = this.font;
        this.ctx.fillStyle = 'green';
        this.ctx.textBaseline = 'top';
        this.ctx.fillText(tempLine.lineText, tempLine.lineTextIndent, tempLine.linePositionY);
        this.ctx.lineWidth = 3 + this.strokeWidth;
        this.ctx.strokeStyle = 'blue';
        this.ctx.strokeText(tempLine.lineText, tempLine.lineTextIndent, tempLine.linePositionY);

    }
}

var multiplyValue = function(value, multiplier){
    var str = value;
    var m = multiplier;
    var result = str.match(/(\d*\.?\d*)(.*)/);
    //http://stackoverflow.com/questions/2868947/split1px-into-1px-1-px-in-javascript
    return result[1] * m + result[2];
}

var optimalStrokeWidthPos = function(strokeWidth, posY){
    if ( strokeWidth < 1) {
        posY = Math.round(posY - 0.5) + 0.5;
    } else if ( strokeWidth >= 1 ) {
        strokeWidth = Math.round( strokeWidth );
        if ( strokeWidth % 2 ){
            // odd, posY -> 0.5
            posY = Math.round(posY - 0.5) + 0.5;
        } else {
            // even, posY -> 1
            posY = Math.round(posY);
        }
    }
    return {
        strokeWidth: strokeWidth,
        posY: posY
    }
}

function SingleUnderline(element, underlineStyles, elementStyles) {
    //ctor
    this.element = element;

    this.text = this.element.textContent;

    this.underlineStyles = underlineStyles;

    this.elementStyles = elementStyles;
    this.redrawActive = false;

    this.canvas = document.createElement("canvas");
    this.ctx = this.canvas.getContext('2d');
    
    this.ratio = window.devicePixelRatio;
        this.canvas.width = this.elementStyles.width*this.ratio;
        this.canvas.height = this.elementStyles.height*this.ratio;
        this.element.appendChild(this.canvas);
        this.canvas.style.width =  this.elementStyles.width + 'px';

        this.ctx.font = this.font = this.elementStyles.fontStyle + ' ' 
                        + multiplyValue(this.elementStyles.fontSize, this.ratio) + ' ' 
                        + this.elementStyles.fontFamily;

    // determine the text-underline-width / strokeWidth
    var dotWidth = this.ctx.measureText('.')['width'];
    if (this.underlineStyles['text-underline-width'] == "auto") {
        // if set to auto, calculate the optimized width based on font
        this.strokeWidth = dotWidth/12;
    } else {
        //if set to px value, todo: other unit such as em?
        this.strokeWidth = this.underlineStyles['text-underline-width'];
        //get number value
        this.strokeWidth = parseFloat(this.strokeWidth)*this.ratio;
    }


    // determine the text-underline-position / underlinePosition
    // text-underline-position in ratio, todo: default and user set position ratio
    if (this.underlineStyles['text-underline-position'] == "auto") {
        // if set to auto, calculate the optimized width based on font
        // console.log(this.elementStyles.baselinePositionRatio);
        this.underlinePosition = parseFloat(this.elementStyles.height) * this.ratio 
                * ( 1 - this.elementStyles.baselinePositionRatio + 
                    this.elementStyles.baselinePositionRatio * 0.4)
                + this.strokeWidth/2;
    } else {
        //if set to ratio value, todo: other unit such as em, px?
        var userUnderlinePosition = parseFloat(this.underlineStyles['text-underline-position']);
        // console.log(this.elementStyles.baselinePositionRatio);
        this.underlinePosition = parseFloat(this.elementStyles.height) * this.ratio * 
                ( 1 - this.elementStyles.baselinePositionRatio + 
                    this.elementStyles.baselinePositionRatio * userUnderlinePosition)
                + this.strokeWidth/2;
    }

    var adjustValue = optimalStrokeWidthPos(this.strokeWidth, this.underlinePosition);
    this.strokeWidth = adjustValue.strokeWidth;
    this.underlinePosition = adjustValue.posY;

    // todo: if last character is a space, remove the space
    textWidth = this.ctx.measureText(this.text).width;

    this.myString = new GuitarString(this.ctx, 
        new Point(0, this.underlinePosition), 
        new Point(textWidth, this.underlinePosition), 
        this.strokeWidth, this.underlineStyles['text-underline-color'], this.ratio);
    this.drawHoles();

}

SingleUnderline.prototype.drawUnderline = function(){
    //  draw the underline
    this.myString.draw();
}

SingleUnderline.prototype.drawHoles = function(){
    // draw the font stroke             
    this.ctx.font = this.font;
    this.ctx.textBaseline = 'top';

    this.ctx.globalCompositeOperation = "destination-out";   

    this.ctx.lineWidth = 2*this.ratio + this.strokeWidth*3.6;
    this.ctx.strokeStyle = 'blue';
    this.ctx.beginPath();
    this.ctx.strokeText(this.text, -0.2, 0);  

    this.ctx.fillStyle = 'green';
    this.ctx.beginPath();
    this.ctx.fillText(this.text, -0.2, 0);
}

SingleUnderline.prototype.clear = function(){
    this.redrawActive = this.myString.redrawActive;
    // clear
    if(this.myString.redrawActive) {
        // this.myString.clear();
        this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
    }
};


SingleUnderline.prototype.update = function(){
    // update
    if(this.myString.redrawActive) {
        this.myString.update();
    }
};


SingleUnderline.prototype.draw = function(){
    // draw
    if(this.redrawActive) {
        this.drawUnderline();
        this.drawHoles();
    }
};

var getElementStyles = function(element){
 // lineHeight, height, ratio, fontFamily, fontSize, fontStyle
    var $this = element;

    var baselinePositionRatio = baselineRatio(element);
    var lineHeight = parseFloat(window.getComputedStyle($this, null)
            .getPropertyValue("line-height"));
    var fontFamily = window.getComputedStyle($this, null)
            .getPropertyValue("font-family");
    var fontSize = window.getComputedStyle($this, null)
            .getPropertyValue("font-size");
    var fontStyle = window.getComputedStyle($this, null)
            .getPropertyValue("font-style");
    var width = $this.getBoundingClientRect().width;
    var height = $this.getBoundingClientRect().height;
    var parentWidth = $this.parentNode.getBoundingClientRect().width;


    var offsetLeft = $this.offsetLeft;
    var parentOffsetLeft = $this.parentNode.offsetLeft;
    var canvasLeft = parentOffsetLeft - offsetLeft;
    var textIndent = offsetLeft - parentOffsetLeft;

    // canvas.style.left= canvasLeft + 'px';   
    return {
        lineHeight: lineHeight,
        width: width,
        height: height,
        parentWidth: parentWidth,
        fontFamily: fontFamily,
        fontSize: fontSize,
        fontStyle: fontStyle,
        baselinePositionRatio: baselinePositionRatio,
        canvasLeft: canvasLeft,
        textIndent: textIndent
    }
};

window.requestAnimFrame = (function(callback) {
	return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
	function(callback) {
	  window.setTimeout(callback, 1000 / 60);
	};
})();

var myUnderlines = [];
var myMultipleUnderlines = [];
window.onload = function() {
	var underlineElements = document.querySelectorAll(".underline");
    for(var n = 0; n < underlineElements.length; n++) {

    	var element = underlineElements[n];

    	var underlineStyles = {
    		'text-underline-color': '#000',
    		'text-underline-position': 'auto', // could be ratio or todo: px 
    		'text-underline-skip': true,
    		'text-underline-width': 'auto' // could be auto or px or ratio
    	}


    	var elementStyles = getElementStyles(element);
    	// single line or multiple line?
		if (elementStyles.height > elementStyles.lineHeight) {
			// multiple lines
			// console.log('multiple lines');
    		var myUnderline = new MultipleUnderline(element, underlineStyles, elementStyles);
    		// myUnderline.update();
    		// myUnderline.draw();
    		myUnderlines.push(myUnderline);
		} else {
			// single line
    		var myUnderline = new SingleUnderline(element, underlineStyles, elementStyles);
    		myUnderlines.push(myUnderline);
		}

		// if(window.device)
    }
}


function animate() {	

	for(var i = 0; i < myUnderlines.length; i++) {
	    var myUnderline = myUnderlines[i];

		// clear
	    myUnderline.clear();
	    
		// update
		myUnderline.update();
		
		// draw stuff
	    myUnderline.draw();
	}

	
	// request new frame
	requestAnimFrame(function() {
	  animate();
	});
}
animate();

//audio play multiple channels at the same time: http://www.storiesinflight.com/html5/audio.html
var channel_max = 10; // number of channels
audiochannels = new Array();
for (a = 0; a < channel_max; a++) { // prepare the channels
    audiochannels[a] = new Array();
    audiochannels[a]['channel'] = new Audio(); // create a new audio object
    audiochannels[a]['finished'] = -1; // expected end time for this channel
}

function play_multi_sound(s) {
    for (a = 0; a < audiochannels.length; a++) {
        thistime = new Date();
        if (audiochannels[a]['finished'] < thistime.getTime()) { // is this channel finished?
            audiochannels[a]['finished'] = thistime.getTime() + document.getElementById(s).duration * 1000;
            audiochannels[a]['channel'].src = document.getElementById(s).src;
            audiochannels[a]['channel'].load();
            audiochannels[a]['channel'].play();
            break;
        }
    }
}

var is_chrome = navigator.userAgent.toLowerCase().indexOf('chrome') > -1;


var circleCenter = function(startPoint, thirdPoint, endPoint){
    var dy1 = thirdPoint.y - startPoint.y;
    var dx1 = thirdPoint.x - startPoint.x;
    var dy2 = endPoint.y - thirdPoint.y;
    var dx2 = endPoint.x - thirdPoint.x;

    var aSlope = dy1/dx1;
    var bSlope = dy2/dx2;  


    var centerX = (aSlope*bSlope*(startPoint.y - endPoint.y) + bSlope*(startPoint.x + thirdPoint.x)
        - aSlope*(thirdPoint.x+endPoint.x) )/( 2* (bSlope-aSlope) );
    var centerY = -1*(centerX - (startPoint.x+thirdPoint.x)/2)/aSlope +  (startPoint.y+thirdPoint.y)/2;
    var r = dist(centerX, centerY, startPoint.x, startPoint.y)

    return {
        x: centerX,
        y: centerY,
        r: r
    };
}

var dist = function(x, y, x0, y0){
    return Math.sqrt((x -= x0) * x + (y -= y0) * y);
};

var Point = function (x,y){
    this.x=x;
    this.y=y;
}


var intersects = function(a, b, c, d, p, q, r, s) {
    // returns true if the line from (a,b)->(c,d) intersects with (p,q)->(r,s)
    var det, gamma, lambda;
    det = (c - a) * (s - q) - (r - p) * (d - b);
    if (det === 0) {
        return false;                    
    } else {
        lambda = ((s - q) * (r - a) + (p - r) * (s - b)) / det;
        gamma = ((b - d) * (r - a) + (c - a) * (s - b)) / det;
        return (0 < lambda && lambda < 1) && (0 < gamma && gamma < 1);
    }
};

var musicLevel = function(startPoint, endPoint, ratio){
    var length = dist(startPoint.x, startPoint.y, endPoint.x, endPoint.y)/ratio;

    level = Math.floor(length/30);
    if (level > 19 ) {
        level = 19;
    }
    level = 19 - level 
    if (level < 10) {
        level = '0' + level 
    }
    return level;
};
function GuitarString(ctx, startPoint, endPoint, strokeWidth, strokeColor, ratio) {
	//ctor
    this.ctx = ctx;
    this.canvas = ctx.canvas;
	this.startPoint = startPoint;
	this.endPoint = endPoint;
    this.strokeWidth = strokeWidth;
    this.strokeColor = strokeColor;
    this.ratio = ratio;

    this.level = musicLevel(this.startPoint, this.endPoint, this.ratio);

    // this.canvas.width = this.canvas.clientWidth;
    // this.canvas.height = this.canvas.clientHeight*1.2;
    
    this.maxGrabDistance = this.strokeWidth * 2;
    this.maxControlDistance = this.strokeWidth * 6;

    this.ctx.lineWidth = this.strokeWidth;
    this.ctx.strokeStyle = this.strokeColor;
        this.ctx.beginPath();
        this.ctx.moveTo(this.startPoint.x, this.startPoint.y);
        this.ctx.lineTo(this.endPoint.x, this.endPoint.y);
        this.ctx.globalCompositeOperation = "source-over";
        this.ctx.stroke();

    this.currentMouseX;
    this.currentMouseY;
    this.lastMouseX;
    this.lastMouseY;
    this.waveInitX = (this.startPoint.x + this.endPoint.x)/2;
    this.waveInitY = this.startPoint.y - this.maxControlDistance;
    this.waveCount = 0;
    this.damping = 0.9;

	this.thirdPoint = new Point((this.startPoint.x + this.endPoint.x)/2, this.startPoint.y);
    

    // state flags
	this.userInControl = false;
	this.userPlucked = false;
	this.waveInControl = false;
	this.waveFinished = false;
	this.initState = true;
    this.lastRedraw = false;
    this.redrawActive = false;

    //add event listener
	var self = this;
    this.canvas.addEventListener('mouseover',  function(event) { 
        self.mouseOver(self, event);
    }, false);

	this.canvas.addEventListener('mousemove',  function(event) { 
		self.mouseMove(self, event);
	}, false);

    this.canvas.addEventListener ("mouseleave", function(event){
        self.mouseLeave(self, event);
    }, false);

    this.canvas.addEventListener ("mouseout", function(event){
        self.mouseOut(self, event);
    }, false);

    this.canvas.addEventListener("touchstart", function(event) { 
        self.touchDown(self, event);
    }, false);
    this.canvas.addEventListener("touchmove", function(event) { 
        self.touchXY(self, event);
    }, false);
    this.canvas.addEventListener("touchend", function(event) { 
        self.touchUp(self, event);
    }, false);

}

GuitarString.prototype.mouseOver = function(self, event){
    // console.log('mouseOver');
    this.currentMouseX = event.layerX*this.ratio;
    this.currentMouseX = event.layerY*this.ratio;
};
GuitarString.prototype.mouseMove = function (self, event){
    // console.log('mouseMove');
    this.lastMouseX = this.currentMouseX;
    this.lastMouseY = this.currentMouseY;
    this.currentMouseX = event.layerX * this.ratio;
    this.currentMouseY = event.layerY * this.ratio; 

    var radius = circleCenter(  new Point(this.startPoint.x, this.startPoint.y), 
                                new Point(this.currentMouseX, this.currentMouseY), 
                                new Point(this.endPoint.x, this.endPoint.y) ).r;
    var currentWaveDistance = radius - Math.sqrt( Math.pow(radius, 2) - Math.pow((Math.abs(this.endPoint.x - this.startPoint.x))/2, 2) );
    var lastRadius = circleCenter(  new Point(this.startPoint.x, this.startPoint.y), 
                                	new Point(this.lastMouseX, this.lastMouseY), 
                                	new Point(this.endPoint.x, this.endPoint.y) ).r;
    var lastWaveDistance = lastRadius - Math.sqrt( Math.pow(lastRadius, 2) 
                                        - Math.pow((Math.abs(this.endPoint.x - this.startPoint.x))/2, 2) );
    


    var mouseInGrabRange = currentWaveDistance < this.maxGrabDistance 
        && this.currentMouseX > this.startPoint.x
        && this.currentMouseX < this.endPoint.x;

    var lastMouseOutGrabRange = !(lastWaveDistance < this.maxGrabDistance
        && this.lastMouseX > this.startPoint.x
        && this.lastMouseX < this.endPoint.x);

    var mouseOutControlRange = !(currentWaveDistance < this.maxControlDistance 
        && this.currentMouseX > this.startPoint.x
        && this.currentMouseX < this.endPoint.x);

    var lastMouseInControlRange = lastWaveDistance < this.maxControlDistance
        && this.lastMouseX > this.startPoint.x
        && this.lastMouseY < this.endPoint.x;
    
    var mouseCrossed = intersects(this.lastMouseX, this.lastMouseY, 
                            this.currentMouseX, this.currentMouseY,
                            this.startPoint.x, this.startPoint.y,
                            this.endPoint.x, this.endPoint.y);

    if( mouseInGrabRange && lastMouseOutGrabRange && (!this.userInControl) ){
        // console.log('grab!');
        this.initState = false;
        this.userInControl = true;
        this.waveInControl = false;
        this.waveFinished = false;

        this.redrawActive = true;
    } else if ( mouseOutControlRange && lastMouseInControlRange && this.userInControl){
        // console.log('boing!');
        this.initState = false;
        this.userInControl = false;
        this.waveInControl = true;
        this.waveFinished = false;
        this.waveCount = 0;
        // this.waveInitX = this.lastMouseX;
        // this.waveInitY = this.lastMouseY;
        this.waveInitX = (this.startPoint.x + this.endPoint.x)/2;
        this.waveInitY = this.endPoint.y + this.maxControlDistance;
        // play audio
        play_multi_sound('audio' + this.level);
        // createjs.Sound.play('cello_' + this.level);

    } 

    if( (!this.userInControl)&&mouseCrossed ) {
    	// console.log('i just plucked!');
        this.initState = false;
        this.userInControl = false;
        this.waveInControl = true;
        this.waveFinished = false;
        this.redrawActive = true;
        this.waveCount = 0;
        this.waveInitX = (this.startPoint.x + this.endPoint.y)/2;
        this.waveInitY = this.endPoint.y + this.maxGrabDistance * 2 / 3;
    }
};
GuitarString.prototype.mouseLeave = function(self, event){
    // console.log('mouseLeave');
    if( this.userInControl ) {
        this.initState = false;
        this.userInControl = false;
        this.waveInControl = true;
        this.waveFinished = false;
        this.redrawActive = true;
        this.waveCount = 0;

        this.waveInitX = event.layerX*this.ratio;
        this.waveInitY = event.layerY*this.ratio;

    }
};
GuitarString.prototype.mouseOut = function(self, event){
    // console.log('mouseOut');
};
GuitarString.prototype.touchDown = function(self, event){
    // console.log('touchDown');
    this.currentMouseX = event.layerX*this.ratio;
    this.currentMouseX = event.layerY*this.ratio;
};
GuitarString.prototype.touchXY = function (self, event){
    // console.log('touchMove');
    this.lastMouseX = this.currentMouseX;
    this.lastMouseY = this.currentMouseY;
    this.currentMouseX = event.layerX * this.ratio;
    this.currentMouseY = event.layerY * this.ratio; 

    var radius = circleCenter(  new Point(this.startPoint.x, this.startPoint.y), 
                                new Point(this.currentMouseX, this.currentMouseY), 
                                new Point(this.endPoint.x, this.endPoint.y) ).r;
    var currentWaveDistance = radius - Math.sqrt( Math.pow(radius, 2) - Math.pow((Math.abs(this.endPoint.x - this.startPoint.x))/2, 2) );
    var lastRadius = circleCenter(  new Point(this.startPoint.x, this.startPoint.y), 
                                    new Point(this.lastMouseX, this.lastMouseY), 
                                    new Point(this.endPoint.x, this.endPoint.y) ).r;
    var lastWaveDistance = lastRadius - Math.sqrt( Math.pow(lastRadius, 2) 
                                        - Math.pow((Math.abs(this.endPoint.x - this.startPoint.x))/2, 2) );
    


    var mouseInGrabRange = currentWaveDistance < this.maxGrabDistance 
        && this.currentMouseX > this.startPoint.x
        && this.currentMouseX < this.endPoint.x;

    var lastMouseOutGrabRange = !(lastWaveDistance < this.maxGrabDistance
        && this.lastMouseX > this.startPoint.x
        && this.lastMouseX < this.endPoint.x);

    var mouseOutControlRange = !(currentWaveDistance < this.maxControlDistance 
        && this.currentMouseX > this.startPoint.x
        && this.currentMouseX < this.endPoint.x);

    var lastMouseInControlRange = lastWaveDistance < this.maxControlDistance
        && this.lastMouseX > this.startPoint.x
        && this.lastMouseY < this.endPoint.x;
    
    var mouseCrossed = intersects(this.lastMouseX, this.lastMouseY, 
                            this.currentMouseX, this.currentMouseY,
                            this.startPoint.x, this.startPoint.y,
                            this.endPoint.x, this.endPoint.y);

    if( mouseInGrabRange && lastMouseOutGrabRange && (!this.userInControl) ){
        // console.log('grab!');
        this.initState = false;
        this.userInControl = true;
        this.waveInControl = false;
        this.waveFinished = false;

        this.redrawActive = true;
    } else if ( mouseOutControlRange && lastMouseInControlRange && this.userInControl){
        // console.log('boing!');
        this.initState = false;
        this.userInControl = false;
        this.waveInControl = true;
        this.waveFinished = false;
        this.waveCount = 0;
        // this.waveInitX = this.lastMouseX;
        // this.waveInitY = this.lastMouseY;
        this.waveInitX = (this.startPoint.x + this.endPoint.x)/2;
        this.waveInitY = this.endPoint.y + this.maxControlDistance;
        // play audio
        play_multi_sound('audio' + this.level);

    } 

    if( (!this.userInControl)&&mouseCrossed ) {
        // console.log('i just plucked!');
        this.initState = false;
        this.userInControl = false;
        this.waveInControl = true;
        this.waveFinished = false;
        this.redrawActive = true;
        this.waveCount = 0;
        this.waveInitX = (this.startPoint.x + this.endPoint.y)/2;
        this.waveInitY = this.endPoint.y + this.maxGrabDistance * 2 / 3;
        // play audio
        // play_multi_sound('audio' + this.level);

    }
};
GuitarString.prototype.touchUp = function(self, event){
    // console.log('touchUp');
    if( this.userInControl ) {
        this.initState = false;
        this.userInControl = false;
        this.waveInControl = true;
        this.waveFinished = false;
        this.redrawActive = true;
        this.waveCount = 0;

        this.waveInitX = event.layerX*this.ratio;
        this.waveInitY = event.layerY*this.ratio;

    }
};


GuitarString.prototype.clear = function(){
	// clear
    // if(this.redrawActive){
    	// this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
    // }
};

GuitarString.prototype.update = function(){
	// console.log(this.redrawActive);
	// if(this.redrawActive){
		if ( this.userInControl ){
            this.thirdPoint = new Point(this.currentMouseX, this.currentMouseY);
        }
        if ( this.waveInControl ){
            var waveX = this.waveInitX;
            var waveY = this.startPoint.y + 
                    (this.waveInitY-this.startPoint.y)
                    *Math.cos(this.waveCount/5*Math.PI)
                    *Math.pow(this.damping, this.waveCount);
    
            if ( Math.pow(this.damping, this.waveCount) > 0.03) {
                // still waving ....
                this.thirdPoint = new Point(waveX, waveY);
                this.waveCount++;
            } else {
                // wave damped to a straight line, wave is finished
                this.waveInControl = false;
                this.waveFinished = true;
                this.lastRedraw = true;
                this.thirdPoint = new Point(waveX, waveY);
            }
        }
	// }
}

GuitarString.prototype.draw = function(){
    // if(this.redrawActive){   
        // draw stuff
    // }
    if(this.lastRedraw) {
        this.drawLine();
        this.lastRedraw = false;
        this.redrawActive = false;
    } else {
        this.drawArc(this.startPoint, this.thirdPoint, this.endPoint);
    }
};
GuitarString.prototype.drawLine = function(){
    // draw a line instead of a flat curve when it stops redraw, pixel-perfect  
    this.ctx.lineWidth = this.strokeWidth;
    this.ctx.strokeStyle = this.strokeColor;
        this.ctx.beginPath();
        this.ctx.moveTo(this.startPoint.x, this.startPoint.y);
        this.ctx.lineTo(this.endPoint.x, this.endPoint.y);
        this.ctx.globalCompositeOperation = "source-over";
        this.ctx.stroke();
};


GuitarString.prototype.drawArc = function(startPoint, thirdPoint, endPoint){
    var ctx = this.ctx;
    ctx.lineWidth = this.strokeWidth;
    ctx.strokeStyle = this.strokeColor;

    var centerObject = circleCenter( new Point(startPoint.x, startPoint.y), 
                                     new Point(thirdPoint.x, thirdPoint.y), 
                                     new Point(endPoint.x, endPoint.y) );
    var centerX = centerObject.x;
    var centerY = centerObject.y;
    var r = centerObject.r

    var angle = Math.atan2(centerX-startPoint.x, centerY-startPoint.y);
    // console.log(centerObject);
    if (!angle){
        ctx.beginPath();
        ctx.moveTo(startPoint.x, startPoint.y);
        ctx.lineTo(endPoint.x, endPoint.y);
    } else {
    	if( angle > Math.PI/2) {
	        ctx.beginPath();
	        ctx.arc(centerX, centerY, r, Math.PI * 1.5-angle, Math.PI * 1.5 + angle, true);
	    } else {
	        ctx.beginPath();
	        ctx.arc(centerX, centerY, r, Math.PI * 1.5-angle, Math.PI * 1.5 + angle, false);
	    }
    }
    ctx.globalCompositeOperation = "source-over";
    ctx.stroke();

}


            
          
!
999px
🕑 One or more of the npm packages you are using needs to be built. You're the first person to ever need it! We're building it right now and your preview will start updating again when it's ready.
Loading ..................

Console