A jQuery plugin that fades html elements based on their proximity to a source
by Derek Anderson - http://mediaupstream.com

`$('#gallery img').galleryFocus();`

// 'radius' - default: 400 - set the source radius size
// 'fadeTo' - default: 0.2 - the min/max value to fade elements to depending on the value of 'invert'
// 'source' - default: 'cursor' - if set to a class or ID the source will be the center of that DOM element
// 'invert' - default: false - Inverts the direction in which elements fade from the 'source'  
// 'overlay' - default: false - displays an overlay to visualize the 'source' influence

$('#gallery img').galleryFocus({
  'radius': 800,
  'fadeTo': 0.0,
  'source': '#source-div',
  'invert': true,
  'overlay': true
});

• overlay (value)
• update ()
• source (value)
• set (key, value)
• get (key)

Usage is as follows:

toggle overlay on/off
$('#gallery img').galleryFocus('overlay', true);

updates cached positions of all elements, may be required in some cases
$('#gallery img').galleryFocus('update');

set to 'cursor' to bind source to the cursor, or set to a single DOM element eg: '#some-div' or '.a-single-element'
$('#gallery img').galleryFocus('source', 'cursor');

changes the options value
$('#gallery img').galleryFocus('set', 'radius','200');

returns the options value
$('#gallery img').galleryFocus('get','radius');