modernizr/feature-detects/canvas/winding.js

Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.

/*!
{
  "name": "canvas winding support",
  "property": ["canvaswinding"],
  "tags": ["canvas"],
  "async" : false,
  "notes": [{
    "name": "Article",
    "href": "https://blogs.adobe.com/webplatform/2013/01/30/winding-rules-in-canvas/"
  }]
}
!*/
/* DOC
Determines if winding rules, which controls if a path can go clockwise or counterclockwise
*/
define(['Modernizr', 'createElement', 'test/canvas'], function(Modernizr, createElement) {

  Modernizr.addTest('canvaswinding', function() {
    if (Modernizr.canvas === false) {
      return false;
    }
    var ctx = createElement('canvas').getContext('2d');

    ctx.rect(0, 0, 10, 10);
    ctx.rect(2, 2, 6, 6);
    return ctx.isPointInPath(5, 5, 'evenodd') === false;
  });

});