javascript - Canvas rotating particles -

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do might know how make kind of animation. how managed see more word canvas javascript technique.

http://cuberto.com/

thank you

here's single arc on blue background going around , around. achieved drawing white arc on blue background.

fiddle:

https://jsfiddle.net/07d69v39/1/

 //coordinates of rectangle   var xp = 125;   var yp = 125;   var radius = 45;      //how far move arc each time:   var anglestep = math.pi * 0.1;   //how move arc:   var steptime = 50;     var currentstep = 0;  function dodraw() {     var can = document.getelementbyid("mycanvas");   can.width = 250;   can.height = 250;   var context = can.getcontext("2d");    //erase canvas painting blue:   context.fillstyle="#0000ff";   context.fillrect(0, 0, 250, 250);    //set drawing color white:   context.strokestyle="#ffffff";   context.linewidth=5;   context.arc(xp, yp, radius, 0 + currentstep, 1.5*math.pi + currentstep);   context.stroke();    //make sure maintain currentstep angle doesn't overflow:   currentstep = currentstep + anglestep;   if (currentstep>math.pi * 2) {     currentstep = currentstep - math.pi * 2;   }    //wait, , call function again animate:   settimeout(function() {     dodraw();   }, steptime);  }  dodraw();

to complete effect, need multiple concentric arcs, traveling in opposite directions:

i placed values individual arc behavior in circles[] array:

https://jsfiddle.net/07d69v39/3/

 //coordinates of rectangle   var xp = 125;   var yp = 125;    var circles = [     {         radius: 45,       step: 0,       direction: true,       speed: math.pi * 0.1,     },     {         radius: 42,       step: 0,       direction: false,       speed: math.pi * 0.05     },     {         radius: 39,       step: 0,       direction: true,       speed: math.pi * 0.07     },     {         radius: 36,       step: 0,       direction: false,       speed: math.pi * 0.02     },      {         radius: 33,       step: 0,       direction: true,       speed: math.pi * 0.06     },      {         radius: 30,       step: 0,       direction: false,       speed: math.pi * 0.04     }     ];    //how move arc:   var steptime = 50;  function dodraw() {     var can = document.getelementbyid("mycanvas");   can.width = 250;   can.height = 250;   var context = can.getcontext("2d");   context.imagesmoothingenabled= true;    //erase canvas painting blue:   context.fillstyle="#0000ff";   context.fillrect(0, 0, 250, 250);    //set drawing color white:   context.strokestyle="#ffffff";   context.linewidth = 4;    (var = 0; i<circles.length;i++) {     var arc = circles[i];     maintainarc(context, arc);   }    //wait, , call function again animate:   settimeout(function() {     dodraw();   }, steptime);  }  function maintainarc(context, arc) {     var radius = arc.radius;   var step = arc.step;   context.beginpath();     context.arc(xp, yp, radius, 0 + step, 1.5*math.pi + step);    context.stroke();     //maintain step angle differently clockwise , counter clockwise   if (arc.direction) {     step = step + arc.speed;     if (step>math.pi * 2) {         step = step - math.pi * 2;     }   } else {     step = step - arc.speed;     if (step<math.pi * 2) {         step = step + math.pi * 2;     }   }   arc.step = step; }      dodraw();

what's missing artistic flare make revolving circles align 'c' @ proper moment. see 'c' in example provided fades out page load completes. not that.


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