cssAudio - ActiveCSS - ActiveGeneric - ActiveHTML - ActiveImage - ActiveJS - ActiveSVG - ActiveText - Activefile-genericVideo - Activehtmlicon-personicon-teamoctocatspinnerstartv

Pen Settings

CSS Base

Vendor Prefixing

Add External CSS

These stylesheets will be added in this order and before the code you write in the CSS editor. You can also add another Pen here, and it will pull the CSS from it. Try typing "font" or "ribbon" below.

Quick-add: + add another resource

Add External JavaScript

These scripts will run in this order and before the code in the JavaScript editor. You can also link to another Pen here, and it will run the JavaScript from it. Also try typing the name of any popular library.

Quick-add: + add another resource

Code Indentation

     

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

            
              $light: #fbfbfe;
$primary: #234549;
$red: #FF4B47;
$green: #40E64F;
$yellow: #E0C93B;
$orange: #F58F39;

body {
  background: $primary;
  user-select: none;
  overflow: hidden;
}

p {
  color: $red;
  width: 4rem;
  height: 4rem;
  line-height: 4rem;
  font-size: 1.4rem;
  border: .5rem solid $red;
  border-radius: 50%;
  display: inline-block;
  position: absolute;
  z-index: 100;
  top: 8rem;
  left: 2rem;
  display: none;
  touch-action: none;

  &.animate {
    animation: spring-translate .8s 0s 1 linear forwards;
  }
  
  @media all and (min-height: 20em) {
    left: 20%;
  }
}
p {
  top: 2rem;
  display: block;
  
  @media all and (min-height: 30em) {
    top: 25%;
  }
}

            
          
!
            
              //adapted from Framer.js calculations, https://github.com/koenbok/Framer/ which match how some Adobe products expect inputs

  var Spring, SpringCurve, Springer, defaults;
  var __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };

  defaults = {
    tension: 80,
    friction: 8,
    velocity: 0,
    speed: 1 / 60.0,
    tolerance: 0.1
  };

  function springAccelerationForState(state) {
    return (-state.tension * state.x) - (state.friction * state.v);
  }

  function springEvaluateState(initial) {
    var output = {
      dx: initial.v,
      dv: springAccelerationForState(initial)
    };
    return output;
  }

  function springEvaluateStateWithDerivative(initial, dt, derivative) {
    var state = {
      x: initial.x + derivative.dx * dt,
      v: initial.v + derivative.dv * dt,
      tension: initial.tension,
      friction: initial.friction
    };
    var output = {
      dx: state.v,
      dv: springAccelerationForState(state)
    };
    return output;
  }

  function springIntegrateState(state, speed) {
    var a, b, c, d, dvdt, dxdt;
    a = springEvaluateState(state);
    b = springEvaluateStateWithDerivative(state, speed * 0.5, a);
    c = springEvaluateStateWithDerivative(state, speed * 0.5, b);
    d = springEvaluateStateWithDerivative(state, speed, c);
    dxdt = 1.0 / 6.0 * (a.dx + 2.0 * (b.dx + c.dx) + d.dx);
    dvdt = 1.0 / 6.0 * (a.dv + 2.0 * (b.dv + c.dv) + d.dv);
    state.x = state.x + dxdt * speed;
    state.v = state.v + dvdt * speed;
    return state;
  }

  Spring = (function() {
    function Spring(args) {
      this.next = __bind(this.next, this);
      this.reset = __bind(this.reset, this);
      args = args || {};
      this.velocity = args.velocity || defaults.velocity;
      this.tension = args.tension || defaults.tension;
      this.friction = args.friction || defaults.friction;
      this.speed = args.speed || defaults.speed;
      this.tolerance = args.tolerance || defaults.tolerance;
      this.reset();
    }

    Spring.prototype.reset = function() {
      this.startValue = 0;
      this.currentValue = this.startValue;
      this.endValue = 100;
      this.moving = true;
      return this.moving;
    };

    Spring.prototype.next = function() {
      var targetValue = this.currentValue;
      var stateBefore = {
        x: targetValue - this.endValue,
        v: this.velocity,
        tension: this.tension,
        friction: this.friction
      };
      var stateAfter = springIntegrateState(stateBefore, this.speed);
      this.currentValue = this.endValue + stateAfter.x;
      var finalVelocity = stateAfter.v;
      var netFloat = stateAfter.x;
      var net1DVelocity = stateAfter.v;
      var netValueIsLow = Math.abs(netFloat) < this.tolerance;
      var netVelocityIsLow = Math.abs(net1DVelocity) < this.tolerance;
      var stopSpring = netValueIsLow && netVelocityIsLow;
      this.moving = !stopSpring;
      if (stopSpring) {
        finalVelocity = 0;
        this.currentValue = this.endValue;
      }
      this.velocity = finalVelocity;
      return this.currentValue;
    };

    Spring.prototype.all = function() {
      var count = 0,
          results = [];
      this.reset();
      while (this.moving) {
        if (count > 3000) {
          throw Error("Spring: too many values");
        }
        count++;
        results.push(this.next());
      }
      
      return results;
    };

    Spring.prototype.time = function() {
      return this.all().length * this.speed;
    };

    return Spring;

  })();

  SpringCurve = function(tension, friction, velocity, fps) {
    var spring;
    spring = new Spring({
      tension: tension,
      friction: friction,
      velocity: velocity,
      speed: 1 / fps
    });
    return spring.all();
  };

  Springer = (function() {
    function Keyframer(args) {
      args = args || {};
      args.initial = args.initial || {};
      args.result = args.result || {};
      this.tension = args.tension;
      this.friction = args.friction;
      this.animationName = args.animationName || ('animation' + Math.floor(Math.random() *100000));
      this.initial = {
        scale: args.initial.scale || 1,
        translateX: args.initial.translateX || 0,
        translateY: args.initial.translateY || 0,
        translateZ: args.initial.translateZ || 0,
      };
      this.result = {
        scale: args.result.scale || 1,
        translateX: args.result.translateX || 0,
        translateY: args.result.translateY || 0,
        translateZ: args.result.translateZ || 0,
      };
      this.staticTransform = args.staticTransform || '';
      //add distanceX and distanceY
      this.curve = SpringCurve(this.tension, this.friction);
      this.generate();
    }

    Keyframer.prototype.generate = function() {
      var length = this.curve.length;
      var animation = '';
      var animationw = '';
      var differences = {
        scale: this.result.scale - this.initial.scale,
        translateX: (this.result.translateX - this.initial.translateX),
        translateY: (this.result.translateY - this.initial.translateY),
        translateZ: (this.result.translateZ - this.initial.translateZ)
      };
      var frames = [{
        step: 0,
        scale: (this.initial.scale),
        translateX: this.initial.translateX + 'px',
        translateY: this.initial.translateY + 'px',
        translateZ: this.initial.translateZ + 'px'
      }];
      var isScale = (differences.scale !== 0);
      var isTranslate = (differences.translateX !== 0 ||
        differences.translateY !== 0 ||
        differences.translateZ !== 0);


      var originalDirection = true;

      for (var i = 1; i < length; ++i) {
        if ((originalDirection && this.curve[i] <= this.curve[i - 1])
          || (!originalDirection && this.curve[i] > this.curve[i - 1])) {
          frames.push({
            step: (i/length).toFixed(7),
            scale: this.initial.scale + (this.curve[i] / (100))*differences.scale,
            translateX: Math.round(this.initial.translateX + (parseFloat(differences.translateX) * this.curve[i]) / 100) + 'px',
            translateY: Math.round(this.initial.translateY + (parseFloat(differences.translateY) * this.curve[i]) / 100) + 'px',
            translateZ: Math.round(this.initial.translateZ + (parseFloat(differences.translateZ) * this.curve[i]) / 100) + 'px'
          });
          originalDirection = !originalDirection;
        }
      }
      
      frames.push( {
        step: 1,
        scale: this.result.scale,
        translateX: this.result.translateX+'px',
        translateY: this.result.translateY+'px',
        translateZ: this.result.translateZ+'px'
      });
      
      animation = [];

      for (var j = 0, l = frames.length; j < l; ++j) {
        var frame = frames[j];
        var animationStep = {
          offset: frame.step,
          transform: this.staticTransform +
          (isScale ? ' scale('+frame.scale+')' : '' )+
          (isTranslate ? ' translate3d('+frame.translateX+','+frame.translateY+','+frame.translateZ+')' : '' ),
          easing: 'ease-in-out'
        }
        animation.push(animationStep);
      }
      
      //replace this with Web animation api
      
      this.animationSteps = animation;
     /* if (frames && frames.length) {
        this.result = {
          x: frames[frames.length - 1].translateX,
          y: frames[frames.length - 1].translateY
        }
      }*/
    };

    return Keyframer;
  })();



//The code that uses the Keyframer above
var _friction = 2;
var translationElement = document.querySelector('p');
var animateAway = true;

function start(currentX, currentY) {
//console.log(currentX, currentY);
var width = window.innerWidth;
var height = window.outerHeight;

var newX = Math.floor(width * Math.random() / 2);
var newY = Math.floor(height * Math.random() / 2);

  var x = currentX || 0;
  var y = currentY || 0;
  
  var tension = Math.max(Math.abs(newX - currentX), Math.abs(newY - currentY))/10;
  
  if (animateAway) {
    var keyframer = new Springer({
      tension: tension,
      friction: _friction,
      animationName: 'spring-translate',
      initial: {
        translateX: x,
        translateY: y,
        translateZ: 0
      },
      result: {
        translateX: newX,
        translateY: newY,
        translateZ: 0
      }
    });
   //console.log(keyframer.animationSteps);
    var animation = translationElement.animate(keyframer.animationSteps, {
      duration: 800,
      iterations: 1,
      delay: 400,
      fill: 'forwards'
    });
    animation.onfinish = function() {
      //translationElement.style.transform = keyframer.animationSteps[keyframer.animationSteps.length - 1].transform;
      
      start(keyframer.result.translateX, keyframer.result.translateY);
    }
  }
}

start();


            
          
!
999px
Close

Asset uploading is a PRO feature.

As a PRO member, you can drag-and-drop upload files here to use as resources. Images, Libraries, JSON data... anything you want. You can even edit them anytime, like any other code on CodePen.

Go PRO

Loading ..................

Console