ChordJS

Draw guitar chord diagrams on HTML5 canvas

Chords.js is a small javascript library to generate images of guitar chords in HTML. It can display chord boxes, starting frets, barred chords, fingerings and open and muted strings. Based on: http://einaregilsson.com/chord-image-generator/

The original library is a .Net web service that converts urls like:

into images like:

There is a small example website at http://chords.einaregilsson.com where you can try different chords and see how they are constructed for the original library.

To use chords.js you can simply convert the url format of the parent library into markup as follows:

<chord name="D" positions="xx0232" fingers="---132" size="3" ></chord>
<chord name="A" positions="x02220" fingers="--123-" size="3" ></chord>
<chord name="A_5" positions="577655" fingers="134211" size="3" ></chord>

Then include script similar to the following on your page:

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8/jquery.min.js"></script>
<script src="chords.js"></script>
<script type="text/javascript">//<![CDATA[
$(document).ready(function(){
    ChordJS.replace();
});
//]]>
</script>

Documentation

Syntax

<chord name="..." positions="..." fingers="..." size="..." layout="..." strings="..." ></chord> elements

ChordJS.generate(name, positions, fingering, size, layout, strings)

Returns a chord diagram as a canvas element, which can easily be added to the DOM.

Options

name Name of the Chord. E.g.: C#
positions Fret positions for each string. Muted string = x; Open string = 0. E.g.: x02220
fingers
Fingers to use for each string. No finger = -. E.g.: --123- (you can use different characters if you like)
size The size of the chord diagram to generate. E.g.: 3 for medium size or 5 for a pretty big size.
layout (optional, default: '1') The layout for the chord diagram.
'1' would draw the finger names onto the strings and show the string names below the diagram.
'2' would draw the finger names below the chord diagrams and not dispaly the string names.
strings (optional)
Names of the strings. E.g. EADGBe for standard tuning.

ChordJS.replace(baseElement)

Replace <chord> elements with rendered chord diagrams.

baseElement (optional) The element in which to replace the elements.

License

The source is licensed under the GPL.

acspike/ChordJS