Update and commit dist file, including latest zip package.

Gruntfile.js

@@ -22,7 +22,7 @@ module.exports = function (grunt) {
                 ' * high-resolution images to devices with retina displays.\n' +
                 ' */\n',
 
-        clean: ['build', 'pkg'],
+        clean: ['dist'],
 
         jshint: {
             options: {
@@ -61,7 +61,7 @@ module.exports = function (grunt) {
         compress: {
             pkg: {
                 options: {
-                    archive: 'pkg/retina-<%= pkg.version %>.zip'
+                    archive: 'dist/retina-<%= pkg.version %>.zip'
                 },
                 files: [{
                     src: ['**'],

dist/retina.js

@@ -0,0 +1,182 @@
+/*!
+ * Retina.js v1.3.0
+ *
+ * Copyright 2014 Imulus, LLC
+ * Released under the MIT license
+ *
+ * Retina.js is an open source script that makes it easy to serve
+ * high-resolution images to devices with retina displays.
+ */
+
+(function() {
+    var root = (typeof exports === 'undefined' ? window : exports);
+    var config = {
+        // An option to choose a suffix for 2x images
+        retinaImageSuffix : '@2x',
+
+        // Ensure Content-Type is an image before trying to load @2x image
+        // https://github.com/imulus/retinajs/pull/45)
+        check_mime_type: true,
+
+        // Resize high-resolution images to original image's pixel dimensions
+        // https://github.com/imulus/retinajs/issues/8
+        force_original_dimensions: true
+    };
+
+    function Retina() {}
+
+    root.Retina = Retina;
+
+    Retina.configure = function(options) {
+        if (options === null) {
+            options = {};
+        }
+
+        for (var prop in options) {
+            if (options.hasOwnProperty(prop)) {
+                config[prop] = options[prop];
+            }
+        }
+    };
+
+    Retina.init = function(context) {
+        if (context === null) {
+            context = root;
+        }
+
+        var existing_onload = context.onload || function(){};
+
+        context.onload = function() {
+            var images = document.getElementsByTagName('img'), retinaImages = [], i, image;
+            for (i = 0; i < images.length; i += 1) {
+                image = images[i];
+                if (!!!image.getAttributeNode('data-no-retina')) {
+                    retinaImages.push(new RetinaImage(image));
+                }
+            }
+            existing_onload();
+        };
+    };
+
+    Retina.isRetina = function(){
+        var mediaQuery = '(-webkit-min-device-pixel-ratio: 1.5), (min--moz-device-pixel-ratio: 1.5), (-o-min-device-pixel-ratio: 3/2), (min-resolution: 1.5dppx)';
+
+        if (root.devicePixelRatio > 1) {
+            return true;
+        }
+
+        if (root.matchMedia && root.matchMedia(mediaQuery).matches) {
+            return true;
+        }
+
+        return false;
+    };
+
+
+    var regexMatch = /\.\w+$/;
+    function suffixReplace (match) {
+        return config.retinaImageSuffix + match;
+    }
+
+    function RetinaImagePath(path, at_2x_path) {
+        this.path = path || '';
+        if (typeof at_2x_path !== 'undefined' && at_2x_path !== null) {
+            this.at_2x_path = at_2x_path;
+            this.perform_check = false;
+        } else {
+            if (undefined !== document.createElement) {
+                var locationObject = document.createElement('a');
+                locationObject.href = this.path;
+                locationObject.pathname = locationObject.pathname.replace(regexMatch, suffixReplace);
+                this.at_2x_path = locationObject.href;
+            } else {
+                var parts = this.path.split('?');
+                parts[0] = parts[0].replace(regexMatch, suffixReplace);
+                this.at_2x_path = parts.join('?');
+            }
+            this.perform_check = true;
+        }
+    }
+
+    root.RetinaImagePath = RetinaImagePath;
+
+    RetinaImagePath.confirmed_paths = [];
+
+    RetinaImagePath.prototype.is_external = function() {
+        return !!(this.path.match(/^https?\:/i) && !this.path.match('//' + document.domain) );
+    };
+
+    RetinaImagePath.prototype.check_2x_variant = function(callback) {
+        var http, that = this;
+        if (this.is_external()) {
+            return callback(false);
+        } else if (!this.perform_check && typeof this.at_2x_path !== 'undefined' && this.at_2x_path !== null) {
+            return callback(true);
+        } else if (this.at_2x_path in RetinaImagePath.confirmed_paths) {
+            return callback(true);
+        } else {
+            http = new XMLHttpRequest();
+            http.open('HEAD', this.at_2x_path);
+            http.onreadystatechange = function() {
+                if (http.readyState !== 4) {
+                    return callback(false);
+                }
+
+                if (http.status >= 200 && http.status <= 399) {
+                    if (config.check_mime_type) {
+                        var type = http.getResponseHeader('Content-Type');
+                        if (type === null || !type.match(/^image/i)) {
+                            return callback(false);
+                        }
+                    }
+
+                    RetinaImagePath.confirmed_paths.push(that.at_2x_path);
+                    return callback(true);
+                } else {
+                    return callback(false);
+                }
+            };
+            http.send();
+        }
+    };
+
+
+    function RetinaImage(el) {
+        this.el = el;
+        this.path = new RetinaImagePath(this.el.getAttribute('src'), this.el.getAttribute('data-at2x'));
+        var that = this;
+        this.path.check_2x_variant(function(hasVariant) {
+            if (hasVariant) {
+                that.swap();
+            }
+        });
+    }
+
+    root.RetinaImage = RetinaImage;
+
+    RetinaImage.prototype.swap = function(path) {
+        if (typeof path === 'undefined') {
+            path = this.path.at_2x_path;
+        }
+
+        var that = this;
+        function load() {
+            if (! that.el.complete) {
+                setTimeout(load, 5);
+            } else {
+                if (config.force_original_dimensions) {
+                    that.el.setAttribute('width', that.el.offsetWidth);
+                    that.el.setAttribute('height', that.el.offsetHeight);
+                }
+
+                that.el.setAttribute('src', path);
+            }
+        }
+        load();
+    };
+
+
+    if (Retina.isRetina()) {
+        Retina.init(root);
+    }
+})();