canvas_support.js

var _canvas = (function(){
  var cv = document.createElement('canvas'),
      c = cv.getContext('2d');
  cv.setAttribute('height', 1);
  cv.setAttribute('width', 1);
  
  var canvas = {}, methods = {}, attributes = {};

  //stolen from Modernizr 1.2dev : http://github.com/Modernizr/Modernizr/blob/master/modernizr.js#L248
  canvas['WebGL'] = (function(){
    var g = document.createElement("canvas"),
    contexts = ["webgl", "experimental-webgl", "moz-webgl", "o-webgl", "webkit-3d", "3d"];
    for (var b = -1; ++b < contexts.length; ) {
      try {
        if (elem.getContext(contexts[b])) return true;  
          } catch(e){ /* NOM NOM NOM */ }
        }
      return false;
  })();
  
  canvas['2dContext'] = {};
  canvas['toDataURL'] = typeof cv['toDataURL'] == 'function';
  
  canvas['2dContext'].methods = (function(meth) {
    for (var i = 0,len=meth.length;i<len;i++) {
      methods[meth[i]] = typeof c[meth[i]] == 'function';
    }
    return methods;
  })('scale rotate translate transform setTransform createLinearGradient createRadialGradient createPattern clearRect fillRect strokeRect beginPath moveTo closePath lineTo quadraticCurveTo bezierCurveTo arcTo arc rect fill stroke clip isPointInPath drawFocusRing fillText strokeText measureText drawImage createImageData getImageData'.split(' '));
  
  canvas['2dContext'].attributes = (function(attr) {
    for (var i = 0, len=attr.length;i<len;i++) {
      attributes[attr[i]] = !!(attr[i] in c);
    };
    return attributes;
  })('strokeStyle fillStyle lineWidth lineCap lineJoin miterLimit shadowColor shadowOffsetX shadowOffsetY shadowBlur font textAlign textBaseline'.split(' '));
  
  return canvas;
})();