html - Make canvas element orbit around/follow mouse -

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http://jsfiddle.net/cby7p/1/

i want cyan dot spin around in canvas chasing mouse, mouse has gravity. think of mouse planet , object comet. tried code, makes cyan dot spin crazy , not follow mouse much. 

<div class="section"> <div id="intro"> <div id="mouse" style="border-radius: 50%; position: absolute;height: 20px;width: 20px;background-color: blue;"></div>  <canvas id="canvas" style="background:black;"> </canvas> <script>     var canvas = document.getelementbyid("canvas");     canvas.width = $(window).width();      canvas.height = $(window).height(); </script> <script>     var canvas = document.queryselector("#canvas")     var ctx = canvas.getcontext("2d");     var mousex;     var mousey;       var kule = {         cx : 100,         cy : 100,         vy : 2,         vx : 2,         r : 5,         e : 1,         color : "cyan"     };        function draw() {         var image = new image();         image.src = "player.png";          ctx.drawimage(image, 100, 100);          var boundsx = canvas.width;         var boundsy = canvas.height;         //ctx.clearrect(0, 0, bounds, bounds);         ctx.fillstyle = kule.color;         ctx.beginpath();             ctx.arc(kule.cx, kule.cy, kule.r, 0, math.pi * 2);             ctx.fill();         ctx.closepath();          var deltax = mousex - kule.cx;         var deltay = mousey - kule.cy;          kule.vy = kule.vy + deltax/1000;         kule.vx = kule.vx + deltay/1000;         kule.cx = kule.cx + kule.vx;         kule.cy = kule.cy + kule.vy;           if (kule.cy + kule.r >= boundsy) {             kule.vy = -kule.vy * kule.e;             kule.vy = -(math.abs(kule.vy)) * kule.e;             }          if (kule.cx + kule.r >= boundsx) {             kule.vx = -kule.vx * kule.e;             kule.vx = -(math.abs(kule.vx)) * kule.e;             }          if (kule.cy - kule.r <= 0) {             kule.vy = kule.vy * kule.e;             kule.vy = (math.abs(kule.vy)) * kule.e;             }          if (kule.cx - kule.r <= 0) {             kule.vx = kule.vx * kule.e;             kule.vx = (math.abs(kule.vx)) * kule.e;             }     }     setinterval(draw, 10);     $(document).on("mousemove",function(event){         mousex = event.pagex;         mousey = event.pagey;                $("#mouse").animate(         {             left:mousex-10,             top:mousey-10         },0)});      </script> </div>

i removed pieces of code simplify answer, here's idea : 

var starttime = (new date()).gettime(); var rotationspeed = 500; // milliseconds full turn var orbitradius = 75; function draw() {     var boundsx = canvas.width;     var boundsy = canvas.height;     ctx.clearrect(0, 0, boundsx, boundsy);     ctx.fillstyle = kule.color;      var currenttime = (new date()).gettime();     var passedtime = currenttime - starttime;     var angle = math.pi * 2 * (passedtime / rotationspeed);      ctx.beginpath();     ctx.arc(mousex + math.cos(angle) * orbitradius, mousey + math.sin(angle) * orbitradius, kule.r, 0, math.pi * 2);     ctx.fill(); }

link jsfiddle


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