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. You can use the CSS from another Pen by using it's URL and the proper URL extention.

+ add another resource

JavaScript

Babel includes JSX processing.

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

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

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="1000" height="400"></canvas>
<p>Press &larr; and &rarr; to move</p>
              
            
!

CSS

              
                body {
  text-align: center;
  font-family: sans-serif;
  background: #FFF8EE;
}

canvas {
  display: block;
  margin: 0 auto;
  border: 5px solid #DDD4C8;
}
              
            
!

JS

              
                
// ----- 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 );
}

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

var TAU = Math.PI * 2;
var PI = 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();
}

function dot( ctx, v ) {
  ctx.beginPath();
  ctx.arc( v.x, v.y, 5, 0, Math.PI * 2 );
  ctx.fill();
  ctx.closePath();
}

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


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

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

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

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

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 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 );
};

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

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

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 = '#B19';
  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.x *= this.movementStrength.x;
  movement.y *= this.movementStrength.y;
  // 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 = 'hsla(0, 100%, 50%, 0.4)';
  ctx.strokeStyle = '#433';
  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;

};

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

// everything connects to coccyx
// coccyx
// shoulderLength
// leftShoulderOffset
// rightShoulderOffset
// leftHipOffset
// rightHipOffset
// armLength
// legLength
// footLength
// position
// hipRunAmplitude
// shoulderRunAmplitude

var PI = Math.PI;
var TAU = PI * 2;


function Skeleton( props ) {
  extend( this, props );
  this.coccyx = new Vector();
  this.neck = new Vector();
  this.resetRunCycle();
  this.idleCycleTheta = 0;
  this.frame = 0;
  this.state = {
    // runningRight: 1,
    // runningLeft: 1,
    idleRight: 1,
    // neutral: 1
  };
  this.animationFrames = {};
}

Skeleton.prototype.update = function() {
  this.frame++;
  for ( var aniName in this.animationFrames ) {
    this.animationFrames[ aniName ]++;
  }
  // this.runCycleTheta += this.state == 'running' ? 0.07 : 0;
  // this.runCycleSpeed = Math.min( 0.15, this.runCycleSpeed + 0.0003 );
  this.runCycleTheta += this.runCycleSpeed;
  this.idleCycleTheta += 0.05;
  this.coccyx.set( this.position );
  // get and set correct rig

  this.updateTransitionState();
  var completeRig = {};
  var rigs = {};
  for ( var rigName in this.state ) {
    var rig = extend( {}, neutralRig );
    var rigMethod = 'get' + capitalize( rigName ) + 'Rig';
    extend( rig, this[ rigMethod ]() );
    rigs[ rigName ] = rig;
  }

  for ( var prop in neutralRig ) {
    var value = 0;
    for ( rigName in rigs ) {
      value += rigs[ rigName ][ prop ] * this.state[ rigName ];
    }
    completeRig[ prop ] = value;
  }

  this.setRig( completeRig );
};

Skeleton.prototype.getRig = function( rigName ) {
  var rigMethod = 'get' + capitalize( rigName ) + 'Rig';
  var rig = extend( {}, neutralRig );
  return extend( rig, this[ rigMethod ]() );
};

function capitalize( str ) {
  return str.charAt(0).toUpperCase() + str.slice(1);
}

Skeleton.prototype.resetRunCycle = function() {
  this.runCycleSpeed = 0.15;
  this.runCycleTheta = TAU * 1/16;
};

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

Skeleton.prototype.startAnimation = function( aniName ) {
  this.animationFrames[ aniName ] = 0;
};

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




var zeroPoint = new Vector();

var neutralRig = {
  offsetX: 0,
  offsetY: 0,
  offset: zeroPoint,
  headRotateY: 0,
  shouldersRotateY: 0,
  shouldersY: 0,
  hipsRotateY: 0,
  hipsY: 0,
  leftElbowAngle: 0,
  leftWristAngle: 0,
  leftKneeAngle: 0,
  leftAnkleAngle: 0,
  leftToeAngle: 0,
  leftFootRotateY: 0,
  rightElbowAngle: 0,
  rightWristAngle: 0,
  rightKneeAngle: 0,
  rightAnkleAngle: 0,
  rightToeAngle: 0,
  rightFootRotateY: 0
};

Skeleton.prototype.getNeutralRig = function() {
  return neutralRig;
};

// get positions and angles for rig, not vectors
Skeleton.prototype.getRunningRightRig = function() {
  var rig = {};
  var quadFactor = 1.5;

  var sin = Math.sin( this.runCycleTheta );
  var cos = Math.cos( this.runCycleTheta );
  var quadSine = quadWave( sin, quadFactor );
  var leftQuadSine = cos < 0 ? quadSine : sin;
  var rightQuadSine = cos > 0 ? quadSine : sin;

  var lift = Math.abs( Math.cos( this.runCycleTheta - 1 ) ) * -40 + 20;
  rig.offsetY = lift;
  //
  rig.headRotateY = 0.2;

  // shoulder
  rig.shouldersRotateY = ( sin + 1 ) * 0.6;
  // elbow
  rig.leftElbowAngle = -rightQuadSine * 1.2 + 0.4;
  rig.rightElbowAngle = leftQuadSine * 1.2 + 0.4;
  // wrist
  rig.leftWristAngle = -leftQuadSine * 0.4 - TAU/4;
  rig.rightWristAngle = rightQuadSine * 0.4 - TAU/4;
  // hip
  rig.hipsRotateY = ( -sin + 1 ) * 0.6;
  // knee
  rig.leftKneeAngle = leftQuadSine * 1.1 - 0.07;
  rig.rightKneeAngle = -rightQuadSine * 1.1 - 0.07;

  var ankleTheta = this.runCycleTheta - TAU/8;
  var normAnkleTheta = normalizeAngle( ankleTheta );
  var ankleAngle = Math.max( 0, Math.sin( normAnkleTheta * 2/3 ) );
  rig.leftAnkleAngle = ankleAngle * 1.7;

  ankleTheta = this.runCycleTheta - TAU/8 + TAU/2;
  normAnkleTheta = normalizeAngle( ankleTheta );
  ankleAngle = Math.max( 0, Math.sin( normAnkleTheta * 2/3 ) );
  rig.rightAnkleAngle = ankleAngle * 1.7;

  rig.leftFootRotateY = TAU/4;
  rig.rightFootRotateY = TAU/4;

  return rig;
};


// get positions and angles for rig, not vectors

// /*
Skeleton.prototype.getRunningLeftRig = function() {
  var rig = {};
  var quadFactor = 1.5;

  var sin = Math.sin( this.runCycleTheta + TAU/2 );
  var cos = Math.cos( this.runCycleTheta + TAU/2 );
  var quadSine = quadWave( sin, quadFactor );
  var quadSineA = cos < 0 ? quadSine : sin;
  var quadSineB = cos > 0 ? quadSine : sin;

  var lift = Math.abs( Math.cos( this.runCycleTheta - 1 ) ) * -40 + 20;
  rig.offsetY = lift;
  //
  rig.headRotateY = -0.2;

  // shoulder
  rig.shouldersRotateY = ( sin + 1 ) * -0.6;
  // elbow
  rig.leftElbowAngle = -quadSineA * 1.2 - 0.4;
  rig.rightElbowAngle = quadSineB * 1.2 - 0.4;
  // wrist
  rig.leftWristAngle = -quadSineA * 0.4 + TAU/4;
  rig.rightWristAngle = quadSineB * 0.4 + TAU/4;
  // hip
  rig.hipsRotateY = ( -sin + 1 ) * -0.6;
  // knee
  rig.leftKneeAngle = quadSineB * 1.1 + 0.07;
  rig.rightKneeAngle = -quadSineA * 1.1 + 0.07;

  var ankleTheta = this.runCycleTheta - TAU/8;
  var normAnkleTheta = normalizeAngle( ankleTheta );
  var ankleAngle = Math.max( 0, Math.sin( normAnkleTheta * 2/3 ) );
  rig.leftAnkleAngle = ankleAngle * -1.7;

  ankleTheta = this.runCycleTheta - TAU/8 + TAU/2;
  normAnkleTheta = normalizeAngle( ankleTheta );
  ankleAngle = Math.max( 0, Math.sin( normAnkleTheta * 2/3 ) );
  rig.rightAnkleAngle = ankleAngle * -1.7;

  rig.leftFootRotateY = -TAU/4;
  rig.rightFootRotateY = -TAU/4;

  return rig;
};
/**/

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

Skeleton.prototype.getIdleRightRig = function() {
  var sin = quadWave( Math.sin( this.idleCycleTheta ), 1 );
  var rig = {
    headRotateY: 0.2,
    shouldersRotateY: sin * -0.2 + 0.4,
    hipsRotateY: 0.6,
    leftFootRotateY: TAU/4,
    rightFootRotateY: TAU/4
  };

  rig.shouldersY = sin * -5 - 5;
  var elbowAngle = sin * 0.1 + 0.1;
  rig.leftElbowAngle = elbowAngle;
  rig.rightElbowAngle = -elbowAngle;
  var wristAngle = sin * -0.1 - 0.1;
  rig.leftWristAngle = wristAngle;
  rig.rightWristAngle = -wristAngle;
  return rig;
};

Skeleton.prototype.getIdleLeftRig = function() {
  var sin = quadWave( Math.sin( this.idleCycleTheta ), 1 );
  var rig = {
    headRotateY: -0.2,
    shouldersRotateY: sin * 0.2 - 0.4,
    hipsRotateY: -0.6,
    leftFootRotateY: -TAU/4,
    rightFootRotateY: -TAU/4
  };

  rig.shouldersY = sin * -5 - 5;
  var elbowAngle = sin * 0.1 + 0.1;
  rig.leftElbowAngle = elbowAngle;
  rig.rightElbowAngle = -elbowAngle;
  var wristAngle = sin * -0.1 - 0.1;
  rig.leftWristAngle = wristAngle;
  rig.rightWristAngle = -wristAngle;
  return rig;
};


Skeleton.prototype.setRig = function( rig ) {
  // save rig
  this.rig = rig;
  // coccyx
  this.coccyx.add({ x: rig.offsetX, y: rig.offsetY });

  this.setRigSide( rig, 'left', -1 );
  this.setRigSide( rig, 'right', 1 );
};

Skeleton.prototype.setRigSide = function( rig, side, direction ) {
  // shoulder
  this[ side + 'Shoulder' ] = Vector.copy( this.coccyx );
  var shoulderCosine = Math.cos( rig.shouldersRotateY ) * direction;
  this[ side + 'Shoulder' ] = Vector.add( this.coccyx, {
    x: shoulderCosine * this.shoulderLength,
    y: -this.torsoLength + rig.shouldersY
  });
  // neck
  this.neck.set( this.coccyx );
  this.neck.y = this[ side + 'Shoulder' ].y;
  // chest
  this[ side + 'Chest' ] = Vector.add( this.neck, {
    x: this.chestPosition.x * shoulderCosine,
    y: this.chestPosition.y
  });
  this[ side + 'Chest' ].x += Math.sin( rig.shouldersRotateY ) * this.chestPosition.z;
  // elbow
  var elbowAngle = rig[ side + 'ElbowAngle' ] + TAU/4;
  this[ side + 'Elbow' ] = Vector.addDistance( this[ side + 'Shoulder' ], this.armLength,
    elbowAngle );
  // wrist
  var wristAngle = rig[ side + 'WristAngle' ] + elbowAngle;
  this[ side + 'Wrist' ] = Vector.addDistance( this[ side + 'Elbow' ], this.armLength,
    wristAngle );
  // hip
  var hipCosine = Math.cos( rig.hipsRotateY ) * direction;
  var hipX = this.hipLength * hipCosine;
  this[ side + 'Hip' ] = Vector.add( this.coccyx, { x: hipX, y: 0 } );
  // butt
  this[ side + 'Butt' ] = Vector.add( this.coccyx, {
    x: this.buttPosition.x * hipCosine,
    y: this.buttPosition.y
  } );
  this[ side + 'Butt' ].x += Math.sin( rig.hipsRotateY ) * this.buttPosition.z;
  // knee
  var kneeAngle = rig[ side + 'KneeAngle' ] + TAU/4;
  this[ side + 'Knee' ] = Vector.addDistance( this[ side + 'Hip' ], this.legLength,
    kneeAngle );
  // ankle
  var ankleAngle = rig[ side + 'AnkleAngle' ] + kneeAngle;
  this[ side + 'Ankle' ] = Vector.addDistance( this[ side + 'Knee' ], this.legLength,
    ankleAngle );
  // toe
  var toeAngle = rig[ side + 'ToeAngle' ] + ankleAngle - TAU/4;
  var footLength = this.footLength * Math.sin( rig[ side + 'FootRotateY' ] );
  this[ side + 'Toe' ] = Vector.addDistance( this[ side + 'Ankle' ], footLength,
    toeAngle );

};

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

Skeleton.prototype.transition = function( rigName, frameCount ) {
  this.transitionFrame = this.frame;
  this.transitionFrameCount = frameCount;
  this.previousState = extend( {}, this.state );
  this.transitionEndRig = rigName;
  this.isTransitioning = true;
  // console.log('start transition', rigName );
};

Skeleton.prototype.updateTransitionState = function() {
  if ( !this.isTransitioning ) {
    return;
  }

  this.state = {};
  var i = ( this.frame - this.transitionFrame ) / this.transitionFrameCount;
  if ( i >= 1 ) {
    // end transition
    this.state[ this.transitionEndRig ] = 1;
    this.isTransitioning = false;
    // console.log('end transition', this.transitionEndRig );
    return;
  }
  for ( var rigName in this.previousState ) {
    this.state[ rigName ] = this.previousState[ rigName ] * ( 1 - i );
  }
  this.state[ this.transitionEndRig ] = ( this.state[ this.transitionEndRig ] || 0 ) + i;
  // this.state[ this.transitionEndRig ] = i;
};


// -------------------------- render -------------------------- //

Skeleton.prototype.render = function( ctx ) {
  ctx.fillStyle = 'hsla(200, 100%, 35%, 0.8)';
  ctx.strokeStyle = 'hsla(200, 100%, 50%, 0.8)';
  ctx.lineWidth = 6;
  ctx.lineCap = 'round';

  // line( ctx, this.torso, this.head );

  line( ctx, this.leftShoulder, this.leftElbow );
  line( ctx, this.leftElbow, this.leftWrist );
  line( ctx, this.leftHip, this.leftKnee );
  line( ctx, this.leftKnee, this.leftAnkle );
  line( ctx, this.leftAnkle, this.leftToe );

  line( ctx, this.rightShoulder, this.rightElbow );
  line( ctx, this.rightElbow, this.rightWrist );
  line( ctx, this.rightHip, this.rightKnee );
  line( ctx, this.rightKnee, this.rightAnkle );
  line( ctx, this.rightAnkle, this.rightToe );

  line( ctx, this.leftShoulder, this.rightShoulder );
  line( ctx, this.leftShoulder, this.coccyx );
  line( ctx, this.rightShoulder, this.coccyx );
  line( ctx, this.leftHip, this.rightHip );

  dot( ctx, this.leftShoulder );
  dot( ctx, this.leftChest );
  dot( ctx, this.leftElbow );
  dot( ctx, this.leftWrist );
  dot( ctx, this.leftHip );
  dot( ctx, this.leftButt );
  dot( ctx, this.leftKnee );
  dot( ctx, this.leftAnkle );
  dot( ctx, this.leftToe );

  dot( ctx, this.rightShoulder );
  dot( ctx, this.rightChest );
  dot( ctx, this.rightElbow );
  dot( ctx, this.rightWrist );
  dot( ctx, this.rightHip );
  dot( ctx, this.rightButt );
  dot( ctx, this.rightKnee );
  dot( ctx, this.rightAnkle );
  dot( ctx, this.rightToe );

  // dot( ctx, this.torso );
  dot( ctx, this.coccyx );
  dot( ctx, this.neck );
  // dot( ctx, this.head );
};

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




var Cole = {};

Cole.init = function( position ) {

  // ----- skeleton ----- //

  this.skeleton = new Skeleton({
    position: new Vector( position.x, position.y ),
    shoulderLength: 50,
    torsoLength: 48,
    hipLength: 35,
    buttPosition: { x: 20, y: -10, z: -10 }, // relative to coccyx, x is reversed for left
    chestPosition: { x: 25, y: 5, z: 8 }, // offset from neck, x is reversed for left
    armLength: 32,
    legLength: 30,
    footLength: 25,
    runningShoulderAmplitude: 15,
    runningHipAmplitude: 10
  });

  // ----- hair ----- //

  this.follicles = [];

  var hairProps = {
    friction: 0.85,
    gravity: new Vector( 0, 0.4 ),
    springStrength: 0.3,
    movementStrength: new Vector( 0.95, 0.01 )
  };

  // position are relative to skeleton.position
  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x -28,
    y: -180,
    segmentLength: 49,
    angle: -1.75,
    curl: 1.17
  })));

  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + 0,
    y: -190,
    segmentLength: 58,
    angle: -1.33,
    curl: 1.15
  })));

  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + 25,
    y: -185,
    segmentLength: 49,
    angle: -1.05,
    curl: 1.15
  })));

  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + 38,
    y: -177,
    segmentLength: 47,
    angle: -0.63,
    curl: 1.15
  })));

  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + 45,
    y: -160,
    segmentLength: 41,
    angle: -0.29,
    curl: 1.15
  })));

  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + 40,
    y: -138,
    segmentLength: 35,
    angle: 0.05,
    curl: 1.15
  })));

  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + 20,
    y: -124,
    segmentLength: 25,
    angle: 0.45,
    curl: 0.8
  })));
  // middle bottom
  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + 5,
    y: -124,
    segmentLength: 21,
    angle: Math.PI / 2,
    curl: 0
  })));
  // compare to 7
  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + -10,
    y: -124,
    segmentLength: 25,
    angle: 2.7,
    curl: -0.8
  })));
  // compare to 6
  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + -22,
    y: -138,
    segmentLength: 41,
    angle: 3.20,
    curl: -1.15
  })));
  // compare to 5
  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + -35,
    y: -160,
    segmentLength: 41,
    angle: -2.8,
    curl: -1.15
  })));
  // compare to 4
  this.follicles.push( new Follicle( extend( hairProps, {
    x: position.x + -20,
    y: -185,
    segmentLength: 47,
    angle: -2.5,
    curl: -1.15
  })));

  // ----- ribbons ----- //

  this.ribbonA = new Ribbon({
    controlPoint: new Vector( position.x, -110 ),
    sections: 30,
    width: 40,
    sectionLength: 9,
    friction: 0.95,
    gravity: new Vector( 0, 0.2 ),
    chainLinkShiftEase: 0.9
  });

  this.ribbonB = new Ribbon({
    controlPoint: new Vector( position.x, -110 ),
    sections: 30,
    width: 40,
    sectionLength: 9,
    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-face-repeat.png';

Cole.update = function() {

  this.previousNeck = Vector.copy( this.skeleton.neck || new Vector() );

  this.skeleton.update();

  var neckMovement = this.previousNeck.y === 0 ? new Vector() :
    Vector.subtract( this.skeleton.neck, this.previousNeck );

  this.ribbonA.controlPoint.add( neckMovement );
  this.ribbonB.controlPoint.add( neckMovement );
  this.ribbonA.update();
  this.ribbonB.update();
  var i, len;

  for ( i=0, len = this.follicles.length; i < len; i++ ) {
    var follicle = this.follicles[i];
    follicle.move( neckMovement );
    follicle.update();
  }

};

// var scale = 1;
var brownSkin = '#963';
var black = '#433';
var magenta = '#B19';

Cole.render = function( ctx ) {
  ctx.save();
  ctx.translate( 0, this.skeleton.position.y );
  this.ribbonA.render( ctx );
  this.ribbonB.render( ctx );

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

  ctx.restore();
  Cole.renderBody( ctx );
};

Cole.renderBody = function( ctx ) {

  var skeleton = this.skeleton;

  // arm in back
  if ( Math.sin( this.skeleton.rig.shouldersRotateY ) >= 0 ) {
    Cole.renderRightIlloArm( ctx );
  } else {
    Cole.renderLeftIlloArm( ctx );
  }
  // legs
  ctx.fillStyle = black;
  ctx.fillRect( skeleton.leftButt.x, skeleton.leftButt.y,
    skeleton.rightButt.x - skeleton.leftButt.x, 42 );
  if ( Math.sin( skeleton.rig.hipsRotateY ) >= 0 ) {
    Cole.renderIlloLeg( ctx, 'right' );
    Cole.renderIlloLeg( ctx, 'left' );
  } else {
    Cole.renderIlloLeg( ctx, 'left' );
    Cole.renderIlloLeg( ctx, 'right' );
  }

  ctx.fillStyle = black;
  // chest
  fillCircle( ctx, skeleton.leftChest, 25 );
  fillCircle( ctx, skeleton.rightChest, 25 );
  // head

  ctx.save();
  ctx.translate( skeleton.neck.x - 135/2, skeleton.neck.y - 145 );
  Cole.renderHead( ctx );
  ctx.restore();

  // arm in front
  if ( Math.sin( skeleton.rig.shouldersRotateY ) >= 0 ) {
    Cole.renderLeftIlloArm( ctx );
  } else {
    Cole.renderRightIlloArm( ctx );
  }
  // inspect
  // ctx.save();
  // ctx.translate( 250, 0 );
  // skeleton.render( ctx );
  // ctx.restore();
};

Cole.renderLeftIlloArm = function( ctx ) {
  var skeleton = this.skeleton;
  renderIlloArm( ctx, skeleton.leftShoulder, skeleton.leftElbow, skeleton.leftWrist );
};

Cole.renderRightIlloArm = function( ctx ) {
  var skeleton = this.skeleton;
  renderIlloArm( ctx, skeleton.rightShoulder, skeleton.rightElbow, skeleton.rightWrist, true );
};

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

  line( ctx, shoulder, elbow );
  ctx.strokeStyle = hasBand ? magenta : brownSkin;
  line( ctx, elbow, wrist );
  ctx.fillStyle = brownSkin;
  fillCircle( ctx, wrist, 28 );
}


Cole.renderIlloLeg = function( ctx, side ) {
  var hip = this.skeleton[ side + 'Hip' ];
  var butt = this.skeleton[ side + 'Butt' ];
  var knee = this.skeleton[ side + 'Knee' ];
  var ankle = this.skeleton[ side + 'Ankle' ];
  var toe = this.skeleton[ side + 'Toe' ];
  var footRotateY = this.skeleton.rig[ side + 'FootRotateY' ];

  ctx.lineCap = 'round';
  ctx.lineJoin = 'round';
  ctx.lineWidth = 55;
  // boot
  ctx.strokeStyle = magenta;
  line( ctx, knee, ankle );
  line( ctx, ankle, toe );
  // thigh
  ctx.strokeStyle = black;
  line( ctx, hip, knee );
  // butt
  ctx.fillStyle = black;
  fillCircle( ctx, butt, 42 );
  // toe circle
  ctx.fillStyle = magenta;
  fillCircle( ctx, toe, Math.max( 0, Math.cos( footRotateY ) ) * 55/2  );
};


var faceCanvas = document.createElement('canvas');
var faceCtx = faceCanvas.getContext('2d');
faceCanvas.width = 400;
faceCanvas.height = 200;
faceCtx.fillStyle = magenta;
faceCtx.fillRect( 0, 0, 400, 200 );
faceCtx.fillStyle = brownSkin;
faceCtx.beginPath();
faceCtx.arc( 200, 260, 160, TAU/2, TAU );
faceCtx.fill();
faceCtx.closePath();

var headCanvas = document.createElement('canvas');
var headCtx = headCanvas.getContext('2d');
headCanvas.width = 135;
headCanvas.height = 135;



Cole.renderHead = function( ctx ) {
  headCtx.clearRect( 0, 0, 135, 135 );
  headCtx.beginPath();
  headCtx.arc( 135/2, 135/2, 135/2, 0, TAU );
  headCtx.fill();
  headCtx.closePath();
  headCtx.globalCompositeOperation = 'source-in';
  var headX = -135 * 4 + ( this.skeleton.rig.headRotateY / TAU ) * 135 * 3;
  headCtx.drawImage( headImg, headX, -40 );
  headCtx.globalCompositeOperation = 'source-over';
  ctx.drawImage( headCanvas, 0, 0 );
};


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



function KeyboardController() {
  // hashes of keys that are down or up
  this.keysDown = {};
  this.onceKeysDown = {};
  this.keysUp = {};
  // hashes of things to do when key goes down/up/repeat down
  this.onceKeyDownActions = {};
  this.repeatKeyDownActions = {};
  this.keyUpActions = {};
  // bind events
  document.addEventListener( 'keydown', this, false );
  document.addEventListener( 'keyup', this, false );
}

// -------------------------- events -------------------------- //

// enable .ontype to trigger from .addEventListener( elem, 'type' )
KeyboardController.prototype.handleEvent = function( event ) {
  var method = 'on' + event.type;
  if ( this[ method ] ) {
    this[ method ]( event );
  }
};

KeyboardController.prototype.onkeydown = function( event ) {
  var keyCode = event.keyCode;
  // dismiss keyboard auto-repeats
  if ( !this.keysDown[ keyCode ] ) {
    // keep track of keys that are down
    this.keysDown[ keyCode ] = true;
    this.onceKeysDown[ keyCode ] = true;
  }

  if ( this.onceKeyDownActions[ keyCode] || this.repeatKeyDownActions[ keyCode ] ) {
    event.preventDefault();
  }
};

KeyboardController.prototype.onkeyup = function( event ) {
  var keyCode = event.keyCode;
  this.keysUp[ keyCode ] = true;
  delete this.keysDown[ keyCode ];
  delete this.onceKeysDown[ keyCode ];
  if ( this.keyUpActions[ keyCode] ) {
    event.preventDefault();
  }
};

// -------------------------- update -------------------------- //

KeyboardController.prototype.update = function() {
  var keyCode;
  for ( keyCode in this.keysDown ) {
    this.triggerAction( keyCode, this.repeatKeyDownActions );
    if ( this.onceKeysDown[ keyCode ] ) {
      this.triggerAction( keyCode, this.onceKeyDownActions );
      // reset flag, only trigger update once, keydown event might repeat
      delete this.onceKeysDown[ keyCode ];
    }
  }

  for ( keyCode in this.keysUp ) {
    this.triggerAction( keyCode, this.keyUpActions );
  }
  // reset keyup hash
  this.keysUp = {};
};

KeyboardController.prototype.triggerAction = function( keyCode, actions ) {
  var action = actions[ keyCode ];
  if ( action ) {
    action();
  }
};


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

var canvas = document.querySelector('canvas');
var ctx = canvas.getContext('2d');
var h = canvas.height;
var w = canvas.width = window.innerWidth - 30;
var TAU = Math.PI * 2;

var logger1 = document.querySelector('.logger1 code');
// var logger2 = document.querySelector('.logger2 code');

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

Cole.init({ x: w, y: 300 });

var coleVelocityX = 0;

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

var keyboard = new KeyboardController();

// left
keyboard.onceKeyDownActions[37] = function() {
  Cole.skeleton.transition( 'runningLeft', 16 );
};
// right
keyboard.onceKeyDownActions[39] = function() {
  Cole.skeleton.transition( 'runningRight', 16 );
};
// left
keyboard.repeatKeyDownActions[37] = function() {
  coleVelocityX -= 4;
};
// right
keyboard.repeatKeyDownActions[39] = function() {
  coleVelocityX += 4;
};

// left
keyboard.keyUpActions[37] = function() {
  Cole.skeleton.transition( 'idleLeft', 16 );
};
// right
keyboard.keyUpActions[39] = function() {
  Cole.skeleton.transition( 'idleRight', 16 );
};

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

function update() {
  coleVelocityX *= 0.85;
  Cole.skeleton.position.x += coleVelocityX;
  Cole.skeleton.position.x = Math.max( 100, Math.min( w*2 - 100, Cole.skeleton.position.x ) );

  keyboard.update();
  Cole.update();

}



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

  ctx.save();
  ctx.translate( 0, 100 );
  ctx.scale( 0.5, 0.5 );
  Cole.render( ctx );
  ctx.restore();
}

var isAnimating = false;

function animate() {
  ctx.clearRect( 0, 0, w, h );
  update();
  render();
  if ( isAnimating ) {
    requestAnimationFrame( animate );
  }
}

function stop() {
  isAnimating = false;
}

function start() {
  isAnimating = true;
  animate();
}

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


start();

              
            
!
999px

Console