Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

JavaScript

Babel is required to process package imports. If you need a different preprocessor remove all packages first.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Behavior

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.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML

              
                <canvas width="600" height="450"></canvas>

<p>Speed <input class="speed-range" type="range" min="0" max="0.2" step="0.01" value="0.07"></p>

              
            
!

CSS

              
                body { text-align: center; }
canvas { display: block; margin: 0 auto; }

              
            
!

JS

              
                /*jshint unused: false, undef: true */
/*global blockSize: false */

// ----- utils ----- //

// extends objects
function extend( a, b ) {
  for ( var prop in b ) {
    a[ prop ] = b[ prop ];
  }
  return a;
}

function modulo( num, div ) {
  return ( ( num % div ) + div ) % div;
}

function normalizeAngle( angle ) {
  return modulo( angle, Math.PI * 2 );
}

function getDegrees( angle ) {
  return angle * ( 180 / Math.PI );
}



// --------------------------  -------------------------- //

function line( ctx, a, b ) {
  ctx.beginPath();
  ctx.moveTo( a.x, a.y );
  ctx.lineTo( b.x, b.y );
  ctx.stroke();
  ctx.closePath();
}

/*jshint browser: true, undef: true, unused: true */

// -------------------------- vector -------------------------- //

function Vector( x, y ) {
  this.x = x || 0;
  this.y = y || 0;
}

Vector.prototype.set = function( v ) {
  this.x = v.x;
  this.y = v.y;
};

Vector.prototype.setCoords = function( x, y ) {
  this.x = x;
  this.y = y;
}

Vector.prototype.add = function( v ) {
  this.x += v.x;
  this.y += v.y;
};

Vector.prototype.subtract = function( v ) {
  this.x -= v.x;
  this.y -= v.y;
};

Vector.prototype.scale = function( s )  {
  this.x *= s;
  this.y *= s;
};

Vector.prototype.multiply = function( v ) {
  this.x *= v.x;
  this.y *= v.y;
};

// custom getter whaaaaaaat
Object.defineProperty( Vector.prototype, 'magnitude', {
  get: function() {
    return Math.sqrt( this.x * this.x  + this.y * this.y );
  }
});

Vector.prototype.equals = function ( v ) {
  return this.x == v.x && this.y == v.y;
};

Vector.prototype.zero = function() {
  this.x = 0;
  this.y = 0;
};

Vector.prototype.block = function( size ) {
  this.x = Math.floor( this.x / size );
  this.y = Math.floor( this.y / size );
};

Object.defineProperty( Vector.prototype, 'angle', {
  get: function() {
    return normalizeAngle( Math.atan2( this.y, this.x ) );
  }
});

// ----- class functions ----- //
// return new vectors

Vector.subtract = function( a, b ) {
  return new Vector( a.x - b.x, a.y - b.y );
};

Vector.add = function( a, b ) {
  return new Vector( a.x + b.x, a.y + b.y );
};

Vector.copy = function( v ) {
  return new Vector( v.x, v.y );
};

Vector.isSame = function( a, b ) {
  return a.x == b.x && a.y == b.y;
};

Vector.getDistance = function( a, b ) {
  var dx = a.x - b.x;
  var dy = a.y - b.y;
  return Math.sqrt( dx * dx + dy * dy );
};

Vector.addDistance = function( vector, distance, angle ) {
  var x = vector.x + Math.cos( angle ) * distance;
  var y = vector.y + Math.sin( angle ) * distance;
  return new Vector( x, y );
};

// --------------------------  -------------------------- //

// -------------------------- Particle -------------------------- //


function Particle( x, y ) {
  this.position = new Vector( x, y );
  this.previousPosition = new Vector( x, y );
}

Particle.prototype.update = function( friction, gravity ) {
  var velocity = Vector.subtract( this.position, this.previousPosition );
  // friction
  velocity.scale( friction );
  this.previousPosition.set( this.position );
  this.position.add( velocity );
  this.position.add( gravity );
};

// --------------------------  -------------------------- //

Particle.prototype.render = function( ctx ) {
  // big circle
  ctx.fillStyle = 'hsla(0, 0%, 10%, 0.5)';
  circle( ctx, this.position.x, this.position.y, 4 );
  // dot
  // ctx.fillStyle = 'hsla(0, 100%, 50%, 0.5)';
  // circle( this.position.x, this.position.y, 5  );
};

function circle( ctx, x, y, radius ) {
  ctx.beginPath();
  ctx.arc( x, y, radius, 0, Math.PI * 2 );
  ctx.fill();
  ctx.closePath();
}

// --------------------------  -------------------------- //

function StickConstraint( particleA, particleB, distance ) {
  this.particleA = particleA;
  this.particleB = particleB;
  if ( distance ) {
    this.distance = distance;
  } else {
    var delta = Vector.subtract( particleA.position, particleB.position );
    this.distance = delta.magnitude;
  }

  this.distanceSqrd = this.distance * this.distance;
}

StickConstraint.prototype.update = function() {
  var delta = Vector.subtract( this.particleA.position, this.particleB.position );
  var mag = delta.magnitude;
  var scale = ( this.distance - mag ) / mag * 0.5;
  delta.scale( scale );
  this.particleA.position.add( delta );
  this.particleB.position.subtract( delta );
};

StickConstraint.prototype.render = function( ctx ) {
  ctx.strokeStyle = 'hsla(200, 100%, 50%, 0.5)';
  ctx.lineWidth = 2;
  line( ctx, this.particleA.position, this.particleB.position );
};


// --------------------------  -------------------------- //

function PinConstraint( particle, position ) {
  this.particle = particle;
  this.position = position;
}

PinConstraint.prototype.update = function() {
  this.particle.position.set( this.position );
};

PinConstraint.prototype.render = function() {};

// --------------------------  -------------------------- //

function SpringAngleConstraint( particleA, particleB, strength, angle ) {
  this.particleA = particleA;
  this.particleB = particleB;
  this.strength = strength;
  if ( angle === undefined ) {
    var delta = Vector.subtract( particleB.position, particleA.position );
    this.angle = delta.angle;
  } else {
    this.angle = angle;
  }
}

SpringAngleConstraint.prototype.update = function() {
  var positionA = this.particleA.position;
  var positionB = this.particleB.position;
  var delta = Vector.subtract( positionB, positionA );
  var deltaAngle = delta.angle;
  var angleDiff = normalizeAngle( this.angle - deltaAngle );
  angleDiff = angleDiff > Math.PI ? angleDiff - Math.PI * 2 : angleDiff;
  var springAngle = deltaAngle + Math.PI / 2;
  var springForce = new Vector( Math.cos( springAngle ), Math.sin( springAngle ) );
  springForce.scale( angleDiff * this.strength * Math.PI * 2 );
  this.particleB.position.add( springForce );
};

SpringAngleConstraint.prototype.render = function( ctx ) {
  var end = Vector.addDistance( this.particleA.position, 50, this.angle );
  ctx.strokeStyle = 'hsla(0, 0%, 50%, 0.5)';
  line( ctx, this.particleA.position, end );
};

// --------------------------  -------------------------- //

function ChainLinkConstraint( particleA, particleB, distance, shiftEase ) {
  this.particleA = particleA;
  this.particleB = particleB;
  this.distance = distance;
  this.distanceSqrd = distance * distance;
  this.shiftEase = shiftEase === undefined ? 0.85 : shiftEase;
}

ChainLinkConstraint.prototype.update = function() {
  var delta = Vector.subtract( this.particleA.position, this.particleB.position );
  var deltaMagSqrd = delta.x * delta.x + delta.y * delta.y;

  if ( deltaMagSqrd <= this.distanceSqrd ) {
    return;
  }
  var newPosition = Vector.addDistance( this.particleA.position, this.distance, delta.angle + Math.PI );
  var shift = Vector.subtract( newPosition, this.particleB.position );
  shift.scale( this.shiftEase );
  this.particleB.previousPosition.add( shift );
  this.particleB.position.set( newPosition );
};

// --------------------------  -------------------------- //

function Ribbon( props ) {
  extend( this, props );

  // create particles

  this.particles = [];
  this.constraints = [];
  
  this.controlParticle = new Particle( this.controlPoint.x, this.controlPoint.y );
  var pin = new PinConstraint( this.controlParticle, this.controlPoint );
  this.constraints.push( pin );

  var x = this.controlPoint.x;
  for ( var i=0; i < this.sections; i++ ) {
    var y = this.controlPoint.y + this.sectionLength * i;
    var particle = new Particle( x, y );
    this.particles.push( particle );
    // create links
    var linkParticle = i === 0 ? this.controlParticle : this.particles[ i-1 ];
    var link = new ChainLinkConstraint( linkParticle, particle, this.sectionLength, this.chainLinkShiftEase );
    this.constraints.push( link );
  }
}

Ribbon.prototype.update = function() {
  var i, len;
  for ( i=0, len = this.particles.length; i < len; i++ ) {
    this.particles[i].update( this.friction, this.gravity );
  }

  for ( i=0, len = this.constraints.length; i < len; i++ ) {
    this.constraints[i].update();
  }
  for ( i=0, len = this.constraints.length; i < len; i++ ) {
    this.constraints[i].update();
  }
};

Ribbon.prototype.addBreeze = function( v ) {
  for ( var i=0, len = this.particles.length; i < len; i++ ) {
    this.particles[i].position.add( v );
  }
};

Ribbon.prototype.render = function( ctx ) {
  ctx.strokeStyle = '#d916d9';
  ctx.lineWidth = this.width;
  ctx.lineCap = 'butt';
  ctx.lineJoin = 'round';

  ctx.beginPath();
  ctx.moveTo( this.controlParticle.x, this.controlParticle.y );
  for ( var i=0, len = this.particles.length; i < len; i++ ) {
    var particle = this.particles[i];
    ctx.lineTo( particle.position.x, particle.position.y );
  }
  ctx.stroke();
  ctx.closePath();
  ctx.lineWidth = 1;
};

// --------------------------  -------------------------- //

// x, y
// angle
// springStrength
// curl
// segmentLength
// friction
// gravity
// movementStrength
function Follicle( props ) {
  extend( this, props );
  delete this.x;
  delete this.y;
  this.particleA = new Particle( props.x, props.y );
  var positionB = Vector.addDistance( this.particleA.position, this.segmentLength, this.angle );
  this.particleB = new Particle( positionB.x, positionB.y );
  this.stick0 = new StickConstraint( this.particleA, this.particleB );
  this.springAngle0 = new SpringAngleConstraint( this.particleA, this.particleB, this.springStrength, this.angle );

  var angle1 = this.angle + this.curl;
  var positionC =  Vector.addDistance( this.particleB.position, this.segmentLength, angle1 );
  this.particleC = new Particle( positionC.x, positionC.y );
  this.stick1 = new StickConstraint( this.particleB, this.particleC );
  this.springAngle1 = new SpringAngleConstraint( this.particleB, this.particleC, this.springStrength, angle1 );

  this.controlPoint = new Vector( props.x, props.y );
  this.pin = new PinConstraint( this.particleA, this.controlPoint );
}

Follicle.prototype.update = function() {
  this.particleA.update( this.friction, this.gravity );
  this.particleB.update( this.friction, this.gravity );
  this.particleC.update( this.friction, this.gravity );
  this.stick0.update();
  this.springAngle0.update();
  // update springAngle1's angle
  var delta = Vector.subtract( this.particleB.position, this.particleA.position );
  this.springAngle1.angle = delta.angle + this.curl;

  this.pin.update();
  this.stick1.update();
  this.springAngle1.update();
};

Follicle.prototype.move = function( movement ) {
  movement = Vector.copy( movement );
  this.controlPoint.add( movement );
  movement.scale( this.movementStrength );
  this.particleB.position.add( movement );
  this.particleC.position.add( movement );
  this.particleB.previousPosition.add( movement );
  this.particleC.previousPosition.add( movement );
};

Follicle.prototype.render = function( ctx ) {

  ctx.lineWidth = 46;
  ctx.strokeStyle = '#333';
  ctx.lineCap = 'round';
  ctx.beginPath();
  ctx.moveTo( this.particleA.position.x, this.particleA.position.y );
  ctx.quadraticCurveTo( this.particleB.position.x, this.particleB.position.y,
    this.particleC.position.x, this.particleC.position.y );
  ctx.stroke();
  ctx.closePath();
  // reset line props
  ctx.lineCap = 'butt';
  ctx.lineWidth = 1;
};

// --------------------------  -------------------------- //

var canvas = document.querySelector('canvas');
var ctx = canvas.getContext('2d');
var w = canvas.width;
var h = canvas.height;


// --------------------------  -------------------------- //

// --------------------------  -------------------------- //

var friction = 0.75;
var gravity = new Vector( 0, 0.4 );
var movementStrength = 0.2;
var springStrength = 0.5;

var follicles = [];
var pins = [];

var v = new Vector( 112, 110 );
var follicle1 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 54,
  angle: -1.75,
  curl: 1.17,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle1 );


v = new Vector( 140, 100 );
var follicle2 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 63,
  angle: -1.33,
  curl: 1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle2 );

v = new Vector( 165, 105 );
var follicle3 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 54,
  angle: -1.05,
  curl: 1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle3 );

v = new Vector( 178, 113 );
var follicle4 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 52,
  angle: -0.63,
  curl: 1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle4 );

v = new Vector( 185, 130 );
var follicle5 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 46,
  angle: -0.29,
  curl: 1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle5 );

v = new Vector( 180, 152 );
var follicle6 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 40,
  angle: 0.05,
  curl: 1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle6 );

v = new Vector( 160, 166 );
var follicle7 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 30,
  angle: 0.45,
  curl: 0.8,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle7 );

// middle bottom
v = new Vector( 145, 166 );
var follicle8 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 26,
  angle: Math.PI / 2,
  curl: 0,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle8 );

// compare to 7
v = new Vector( 130, 166 );
var follicle9 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 30,
  angle: 2.7,
  curl: -0.8,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle9 );

// compare to 6
v = new Vector( 118, 152 );
var follicle10 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 46,
  angle: 3.20,
  curl: -1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle10 );

// compare to 5
v = new Vector( 105, 130 );
var follicle11 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 46,
  angle: -2.8,
  curl: -1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle11 );

// compare to 4
v = new Vector( 120, 105 );
var follicle12 = new Follicle({
  x: v.x,
  y: v.y,
  segmentLength: 52,
  angle: -2.5,
  curl: -1.15,
  friction: friction,
  gravity: gravity,
  springStrength: springStrength,
  movementStrength: movementStrength
});
follicles.push( follicle12 );

// --------------------------  -------------------------- //

var ribbon0 = new Ribbon({
  controlPoint: new Vector( 130, 180 ),
  sections: 30,
  width: 40,
  sectionLength: 8,
  friction: 0.95,
  gravity: new Vector( 0, 0.2 ),
  chainLinkShiftEase: 0.9
});

var ribbon1 = new Ribbon({
  controlPoint: new Vector( 130, 180 ),
  sections: 30,
  width: 40,
  sectionLength: 8,
  friction: 0.9,
  gravity: new Vector( 0, 0.25 ),
  chainLinkShiftEase: 0.9
});

// --------------------------  -------------------------- //

var headImg = new Image();
var isHeadImgLoaded;
headImg.onload = function() {
  isHeadImgLoaded = true;
};
headImg.src = 'https://s3-us-west-2.amazonaws.com/s.cdpn.io/82/cole-run-cycle-head.png';

// --------------------------  -------------------------- //

var origin = new Vector( 300, 300 );
var torso = new Vector();
var previousTorso = new Vector();
var coccyx = new Vector();
var head = new Vector();
var leftShoulder, leftElbow, leftWrist, leftHip, leftKnee, leftAnkle, leftToe;
var rightShoulder, rightElbow, rightWrist, rightHip, rightKnee, rightAnkle, rightToe;
var leftThigh, rightThigh;
var leftShoulderOffset = new Vector( -40, 0 );
var rightShoulderOffset = new Vector( 30, 0 );
var shoulderAmplitude = 10;
var armLength = 35;
var leftHipOffset = new Vector( -40, 48 );
var rightHipOffset = new Vector( 10, 48 );
var hipAmplitude = 10;
var legLength = 30;
var footLength = 30;


// --------------------------  -------------------------- //

var cycleTheta = 0;
var cycleSpeed = 0.07;
var PI = Math.PI;
var TAU = PI * 2;

var breeze = new Vector( -0.5, 0 );

function update() {
  previousTorso.set( torso );
  updateCycle();

  var movement = previousTorso.x === 0 ? new Vector() : Vector.subtract( torso, previousTorso );

  ribbon0.controlPoint.add( movement );
  ribbon1.controlPoint.add( movement );
  ribbon0.addBreeze( breeze );
  ribbon1.addBreeze( breeze );
  ribbon0.update();
  ribbon1.update();
  var i, len;
  for ( i=0, len = follicles.length; i < len; i++ ) {
    follicles[i].move( movement );
    follicles[i].update();
  }
  for ( i=0, len = pins.length; i < len; i++ ) {
    pins[i].update();
  }
  for ( i=0, len = follicles.length; i < len; i++ ) {
    follicles[i].stick0.update();
    follicles[i].stick1.update();
  }
}

function updateCycle() {
  cycleTheta += cycleSpeed;

  var sin = Math.sin( cycleTheta );

  torso.set( origin );
  var lift = Math.cos( cycleTheta - 1 );
  torso.y -= Math.abs( lift ) * 40;
  // torso.y -= Math.max( 0, Math.cos( cycleTheta * 2 - 2 ) ) * 20;
  coccyx.set( torso );
  coccyx.y += leftHipOffset.y;
  head.set( torso );
  head.y -= 30;

  // shoulder
  var quadFactor = 1.5;
  leftShoulder = Vector.add( torso, leftShoulderOffset );
  var quadSine = sin > 0 ? quadWave( sin, quadFactor ) : sin;
  // var normTheta = normalizeAngle( cycleTheta );
  // var quadSine = Math.floor( cycleTheta / ( TAU/4) ) % 2 ?  quadWave( sin, squareFactor ) : sin;
  leftShoulder.x += quadSine * shoulderAmplitude;
  // elbow
  var leftElbowAngle = -quadSine * 1.0 + 1.7;
  leftElbow = Vector.addDistance( leftShoulder, armLength, leftElbowAngle );
  // wrist

  var leftWristAngle = leftElbowAngle - quadSine * 0.4 - PI / 2;
  leftWrist = Vector.addDistance( leftElbow, armLength, leftWristAngle );
  // hip
  leftHip = Vector.add( torso, leftHipOffset );
  leftHip.x += -quadSine * hipAmplitude;
  // knee
  var leftKneeAngle = quadSine * 0.9 + 1.5;
  leftKnee = Vector.addDistance( leftHip, legLength, leftKneeAngle );
  leftThigh = Vector.addDistance( leftHip, legLength/2, leftKneeAngle );
  // ankle
  var ankleTheta = cycleTheta - TAU/8;
  var normAnkleTheta = normalizeAngle( ankleTheta );
  var ankleAngle = Math.max( 0, Math.sin( normAnkleTheta * 2/3 ) ) * 2 - 1;
  var leftAnkleAngle = ( ankleAngle + 1 ) * 0.75;
  leftAnkleAngle += leftKneeAngle;
  leftAnkle = Vector.addDistance( leftKnee, legLength, leftAnkleAngle );
  leftToe = Vector.addDistance( leftAnkle, footLength, leftAnkleAngle - TAU/4 );
  // right
  // shoulder
  quadSine = sin < 0 ? quadWave( sin, quadFactor ) : sin;
  rightShoulder = Vector.add( torso, rightShoulderOffset );
  rightShoulder.x += quadSine * shoulderAmplitude * -1;
  // elbow
  var rightElbowAngle = quadSine * 1.0 + 1.7;
  rightElbow = Vector.addDistance( rightShoulder, armLength, rightElbowAngle );
  // wrist
  var rightWristAngle = rightElbowAngle + quadSine * 0.4 - PI / 2;
  rightWrist = Vector.addDistance( rightElbow, armLength, rightWristAngle );
  // hip
  rightHip = Vector.add( torso, rightHipOffset );
  rightHip.x += quadSine * hipAmplitude;
  // knee
  var rightKneeAngle = -quadSine * 0.9 + 1.5;
  rightKnee = Vector.addDistance( rightHip, legLength, rightKneeAngle );
  rightThigh = Vector.addDistance( rightHip, legLength/2, rightKneeAngle );
  // ankle
  ankleTheta = cycleTheta - TAU/8 + TAU/2;
  normAnkleTheta = normalizeAngle( ankleTheta );
  ankleAngle = Math.max( 0, Math.sin( normAnkleTheta * 2/3 ) ) * 2 - 1;
  var rightAnkleAngle = ( ankleAngle + 1 ) * 0.75;
  rightAnkleAngle += rightKneeAngle;
  rightAnkle = Vector.addDistance( rightKnee, legLength, rightAnkleAngle );
  rightToe = Vector.addDistance( rightAnkle, footLength, rightAnkleAngle - TAU/4 );
}

var scale = 1;

function render() {
  ctx.clearRect( 0, 0, w, h );

  ctx.save();
  ctx.scale( scale, scale );
  ctx.save();
  ctx.translate( 150, 50 );
  ribbon0.render( ctx );
  ribbon1.render( ctx );

  for ( var i=0, len = follicles.length; i < len; i++ ) {
    follicles[i].render( ctx );
  }

  ctx.restore();
  renderIllo();
  ctx.restore();
  // renderSkeleton();
}

var brownSkin = '#A74';
var black = '#333';
var magenta = '#B1B';

function renderIllo() {
  // right arm
  renderIlloArm( rightShoulder, rightElbow, rightWrist, true );
  // right leg
  renderIlloLeg( rightHip, rightKnee, rightAnkle, rightThigh, rightToe, black );
  // torso bottom
  ctx.fillStyle = black;
  ctx.beginPath();
  ctx.arc( leftHip.x + 15, leftHip.y - 15, 42, TAU/4, -TAU/4 );
  ctx.fill();
  ctx.closePath();

  ctx.beginPath();
  ctx.arc( rightHip.x - 15, rightHip.y - 15, 42, -TAU/4, TAU/4 );
  ctx.fill();
  ctx.closePath();
  ctx.fillRect( leftHip.x + 14.5, torso.y - 9, ( rightHip.x - 14.5) - (leftHip.x + 14.5), 84 );
  // torso top
  ctx.fillStyle = black;
  fillCircle( Vector.add( torso, { x: -33, y: 0 } ), 25 );
  fillCircle( Vector.add( torso, { x: 18, y: 0 } ), 25 );
  // fillCircle( Vector.add( rightShoulder, { x: -15, y: 0 } ), 25 );
  ctx.fillRect( torso.x - 33, torso.y - 25, 56, 50 );
  // head
  if ( isHeadImgLoaded ) {
    ctx.drawImage( headImg, torso.x - 70, torso.y - 145 );
  }
  // left leg
  renderIlloLeg( leftHip, leftKnee, leftAnkle, leftThigh, leftToe, magenta );
  // left arm
  renderIlloArm( leftShoulder, leftElbow, leftWrist );
}

function renderIlloArm( shoulder, elbow, wrist, hasBand ) {
  ctx.strokeStyle = brownSkin;
  ctx.lineWidth = 45;
  ctx.lineCap = 'round';
  ctx.lineJoin = 'round';

  ctx.beginPath();
  ctx.moveTo( shoulder.x, shoulder.y );
  ctx.lineTo( elbow.x, elbow.y );
  ctx.lineTo( wrist.x, wrist.y );
  ctx.stroke();
  ctx.closePath();

  if ( hasBand ) {
    ctx.strokeStyle = magenta;
    ctx.beginPath();
    ctx.moveTo( elbow.x, elbow.y );
    ctx.lineTo( wrist.x, wrist.y );
    ctx.stroke();
    ctx.closePath();
  }

  // ctx.fillStyle = !hasBand ? magenta : brownSkin;
  ctx.fillStyle = brownSkin;
  fillCircle( wrist, 28 );
}

function fillCircle( v, radius ) {
  ctx.beginPath();
  ctx.arc( v.x, v.y, radius, 0, TAU );
  ctx.fill();
  ctx.closePath();
}

function renderIlloLeg( hip, knee, ankle, thigh, toe, footColor ) {
  ctx.lineWidth = 45;
  ctx.lineCap = 'round';
  ctx.lineJoin = 'round';

  ctx.strokeStyle = black;
  ctx.beginPath();
  ctx.moveTo( hip.x, hip.y );
  ctx.lineTo( knee.x, knee.y );
  ctx.lineTo( ankle.x, ankle.y );
  ctx.stroke();
  ctx.closePath();

  // foot
  ctx.lineCap = 'round';
  ctx.lineWidth = 50;
  ctx.strokeStyle = magenta;
  ctx.beginPath();
  ctx.moveTo( ankle.x, ankle.y );
  ctx.lineTo( toe.x, toe.y );
  ctx.stroke();
  ctx.closePath();
}

function dot( ctx, v ) {
  ctx.beginPath();
  ctx.arc( v.x, v.y, 6, 0, Math.PI * 2 );
  ctx.fill();
  ctx.closePath();
}

// i: sin or cos
// b: square factor
function quadWave( i, b ) {
  return Math.sqrt( ( 1 + b * b ) / ( 1 + b * b * i * i ) ) * i;
}


var isAnimating = false;

function animate() {
  update();
  render();
  requestAnimationFrame( animate );
}

function start() {
  isAnimating = true;
}

// --------------------------  -------------------------- //

animate();

var speedRange = document.querySelector('.speed-range')
speedRange.onchange = function() {
  cycleSpeed = parseFloat( speedRange.value );
};

              
            
!
999px

Console