stars on the follow demo

1 files changed, 74 insertions, 0 deletions

diff --git a/emoji/okstars.js b/emoji/okstars.js
new file mode 100644
index 0000000..4f1cde3
--- /dev/null
+++ b/emoji/okstars.js
@@ -0,0 +1,74 @@
+(function($){
+
+    $.okstars = function(el, options){
+        var base = this;
+        base.$el = $(el);
+        base.el = el;
+        base.$el.data("okstars", base);
+
+        base.init = function () {
+            base.options = $.extend({}, $.okstars.options, options);
+            if (! base.canvas) base.canvas = base.new_canvas();
+            base.context = base.canvas.getContext("2d");
+            base.build();
+            $(window).resize(base.build)
+        };
+
+        base.new_canvas = function () {
+            var canvas = document.createElement("canvas");
+            canvas.style.cssText = "position:fixed;top:0;left:0;z-index:-1;";
+            base.$el.append(canvas);
+            return canvas;
+        };
+        function randrange(a,b){
+          var x = Math.random()
+          return a * (1-x) + b * x
+        }
+        base.build = function () {
+            var w = base.canvas.width = window.innerWidth
+            var h = base.canvas.height = window.innerHeight
+            var context = base.context;
+            var starcount = ~~randrange(base.options.starMin, base.options.starMax)
+            var tt = +new Date()
+            for (var i = 0; i < starcount; i++) {
+                var radius = Math.random() * 2
+                context.fillStyle = base.mottle_gray(base.options.color, base.options.colorrange)
+                context.fillRect( Math.random() * w, Math.random() * h, radius,radius)
+            }
+//            console.log("generated", starcount, "stars in", (+new Date() - tt), "ms")
+        };
+
+        base.clamp = function (x, min, max) {
+            return Math.max(min, Math.min(max, x));
+        };
+        base.mottle_gray = function (color, radius) {
+            var rgb = color.split("")
+            var rgbcolor = 'rgb('
+            var offset = Math.floor(Math.random()*radius*2 - radius)
+            rgbcolor += parseInt(rgb[0], 16) * 16 + offset
+            rgbcolor += ","
+            rgbcolor += parseInt(rgb[1], 16) * 16 + offset
+            rgbcolor += ","
+            rgbcolor += parseInt(rgb[2], 16) * 16 + offset
+            rgbcolor += ")"
+            return rgbcolor
+        };
+
+        base.init();
+    };
+
+    $.okstars.options = {
+        transparent: false,
+        starMin: 100,
+        starMax: 1000,
+        color: "888",
+        colorrange: 128
+    };
+
+    $.fn.okstars = function(options){
+        return this.each(function(){
+            (new $.okstars(this, options));
+        });
+    };
+
+})(jQuery);