gistfile1.txt

/**
 * @author qiao / https://github.com/qiao
 * @author mrdoob / http://mrdoob.com
 * @author alteredq / http://alteredqualia.com/
 * @author WestLangley / http://github.com/WestLangley
 *
 * customized for momentum (zoom and phi/delta) by paulkaplan
 */

THREE.OrbitControls = function ( object, domElement ) {

  this.object = object;
  this.domElement = ( domElement !== undefined ) ? domElement : document;

  // API

  this.enabled = true;

  this.center = new THREE.Vector3();

  this.userZoom = true;
  this.userZoomSpeed = 1.0;

  this.userRotate = true;
  this.userRotateSpeed = 1.0;

  this.userPan = true;
  this.userPanSpeed = 2.0;

  this.autoRotate = false;
  this.autoRotateSpeed = 2.0; // 30 seconds per round when fps is 60

  this.minPolarAngle = 0; // radians
  this.maxPolarAngle = Math.PI; // radians

  this.minDistance = 0;
  this.maxDistance = Infinity;

  this.zoomDampingFactor = 0.2;

  this.momentumDampingFactor = 0.8;
  this.momentumScalingFactor = 0.005;

  this.keys = { LEFT: 37, UP: 38, RIGHT: 39, BOTTOM: 40 };

  // internals

  var scope = this;

  var EPS = 0.000001;
  var PIXELS_PER_ROUND = 1800;

  var rotateStart = new THREE.Vector2();
  var rotateEnd = new THREE.Vector2();
  var rotateDelta = new THREE.Vector2();

  var zoomStart = new THREE.Vector2();
  var zoomEnd = new THREE.Vector2();
  var zoomDelta = new THREE.Vector2();

  var _zoomEnd = 0;
  var _zoomStart = 0;

  var phiDelta = 0;
  var thetaDelta = 0;
  var scale = 1;

  var lastPosition = new THREE.Vector3();

  var STATE = { NONE: -1, ROTATE: 0, ZOOM: 1, PAN: 2 };
  var state = STATE.NONE;

  // events

  var changeEvent = { type: 'change' };


  this.rotateLeft = function ( angle ) {

    if ( angle === undefined ) {

      angle = getAutoRotationAngle();

    }

    thetaDelta -= angle;

  };

  this.rotateRight = function ( angle ) {

    if ( angle === undefined ) {

      angle = getAutoRotationAngle();

    }

    thetaDelta += angle;

  };

  this.rotateUp = function ( angle ) {

    if ( angle === undefined ) {

      angle = getAutoRotationAngle();

    }

    phiDelta -= angle;

  };

  this.rotateDown = function ( angle ) {

    if ( angle === undefined ) {

      angle = getAutoRotationAngle();

    }

    phiDelta += angle;

  };
  
  this.zoomCamera = function(){
    var _this = this;

    var factor = 1.0 + ( _zoomEnd - _zoomStart ) * this.userZoomSpeed;
    scale *= factor;
    

    _zoomStart += ( _zoomEnd - _zoomStart ) * this.zoomDampingFactor;


  };


  this.pan = function ( distance ) {

    distance.transformDirection( this.object.matrix );
    distance.multiplyScalar( scope.userPanSpeed );

    this.object.position.add( distance );
    this.center.add( distance );

  };
  
  this.momentum = function(){
    if(!momentumOn) return;

    // console.log('momentum-ing: '+momentumUp+" "+momentumLeft);

    if(Math.abs(momentumUp + momentumLeft) < 10e-5){ momentumOn = false; return }

    momentumUp   *= this.momentumDampingFactor;
    momentumLeft *= this.momentumDampingFactor;

    thetaDelta -= this.momentumScalingFactor * momentumLeft;
    phiDelta   -= this.momentumScalingFactor * momentumUp;

  };

  this.update = function () {
    this.zoomCamera();
    this.momentum();
    // console.log(scale)

    var position = this.object.position;
    var offset = position.clone().sub( this.center );

    // angle from z-axis around y-axis

    var theta = Math.atan2( offset.x, offset.z );

    // angle from y-axis

    var phi = Math.atan2( Math.sqrt( offset.x * offset.x + offset.z * offset.z ), offset.y );

    if ( this.autoRotate ) {

      this.rotateLeft( getAutoRotationAngle() );

    }

    theta += thetaDelta;
    phi += phiDelta;

    // restrict phi to be between desired limits
    phi = Math.max( this.minPolarAngle, Math.min( this.maxPolarAngle, phi ) );

    // restrict phi to be betwee EPS and PI-EPS
    phi = Math.max( EPS, Math.min( Math.PI - EPS, phi ) );

    var radius = offset.length() * scale;

    // restrict radius to be between desired limits
    radius = Math.max( this.minDistance, Math.min( this.maxDistance, radius ) );

    offset.x = radius * Math.sin( phi ) * Math.sin( theta );
    offset.y = radius * Math.cos( phi );
    offset.z = radius * Math.sin( phi ) * Math.cos( theta );

    position.copy( this.center ).add( offset );

    this.object.lookAt( this.center );

    thetaDelta = 0;
    phiDelta = 0;
    scale = 1;

    if ( lastPosition.distanceTo( this.object.position ) > 0 ) {

      this.dispatchEvent( changeEvent );

      lastPosition.copy( this.object.position );

    }

  };


  function getAutoRotationAngle() {

    return 2 * Math.PI / 60 / 60 * scope.autoRotateSpeed;

  }

  function getZoomScale() {

    return Math.pow( 0.95, scope.userZoomSpeed );

  }

  function onMouseDown( event ) {
    
    momentumOn = false;

    momentumLeft = momentumUp = 0;

    if ( scope.enabled === false ) return;
    if ( scope.userRotate === false ) return;

    event.preventDefault();

    if ( event.button === 0 ) {

      state = STATE.ROTATE;

      rotateStart.set( event.clientX, event.clientY );

    } else if ( event.button === 1 ) {

      state = STATE.ZOOM;

      zoomStart.set( event.clientX, event.clientY );

    } else if ( event.button === 2 ) {

      state = STATE.PAN;

    }

    document.addEventListener( 'mousemove', onMouseMove, false );
    document.addEventListener( 'mouseup', onMouseUp, false );

  }

  var momentumLeft, momentumUp;

  function onMouseMove( event ) {

    if ( scope.enabled === false ) return;

    event.preventDefault();

    if ( state === STATE.ROTATE ) {

      rotateEnd.set( event.clientX, event.clientY );
      rotateDelta.subVectors( rotateEnd, rotateStart );

      momentumLeft = event.webkitMovementX;
      momentumUp   = event.webkitMovementY;
      // momentumLeft += 2 * Math.PI * rotateDelta.x / PIXELS_PER_ROUND * scope.userRotateSpeed;
      // momentumUp   += 2 * Math.PI * rotateDelta.y / PIXELS_PER_ROUND * scope.userRotateSpeed;

      scope.rotateLeft( 2 * Math.PI * rotateDelta.x / PIXELS_PER_ROUND * scope.userRotateSpeed );
      scope.rotateUp( 2 * Math.PI * rotateDelta.y / PIXELS_PER_ROUND * scope.userRotateSpeed );

      rotateStart.copy( rotateEnd );

     }  // else if ( state === STATE.ZOOM ) {

    //   zoomEnd.set( event.clientX, event.clientY );
    //   zoomDelta.subVectors( zoomEnd, zoomStart );

    //   if ( zoomDelta.y > 0 ) {

    //     scope.zoomIn();

    //   } else {

    //     scope.zoomOut();

    //   }

    //   zoomStart.copy( zoomEnd );

    } else if ( state === STATE.PAN ) {

      var movementX = event.movementX || event.mozMovementX || event.webkitMovementX || 0;
      var movementY = event.movementY || event.mozMovementY || event.webkitMovementY || 0;

      scope.pan( new THREE.Vector3( - movementX, movementY, 0 ) );

    }

  }
  
  var momentumOn = false;

  function onMouseUp( event ) {

    momentumOn = true;

    if ( scope.enabled === false ) return;
    if ( scope.userRotate === false ) return;

    document.removeEventListener( 'mousemove', onMouseMove, false );
    document.removeEventListener( 'mouseup', onMouseUp, false );

    state = STATE.NONE;

  }

  function onMouseWheel( event ) {

    if ( scope.enabled === false ) return;
    if ( scope.userZoom === false ) return;
    event.preventDefault();
    event.stopPropagation();

    var delta = 0;

    if ( event.wheelDelta ) { // WebKit / Opera / Explorer 9

      delta = event.wheelDelta / 40;

    } else if ( event.detail ) { // Firefox

      delta = - event.detail / 3;

    }

    _zoomStart += delta * 0.001;

  }

  function onKeyDown( event ) {

    if ( scope.enabled === false ) return;
    if ( scope.userPan === false ) return;

    switch ( event.keyCode ) {

      case scope.keys.UP:
        scope.pan( new THREE.Vector3( 0, 1, 0 ) );
        break;
      case scope.keys.BOTTOM:
        scope.pan( new THREE.Vector3( 0, - 1, 0 ) );
        break;
      case scope.keys.LEFT:
        scope.pan( new THREE.Vector3( - 1, 0, 0 ) );
        break;
      case scope.keys.RIGHT:
        scope.pan( new THREE.Vector3( 1, 0, 0 ) );
        break;
    }

  }

  this.domElement.addEventListener( 'contextmenu', function ( event ) { event.preventDefault(); }, false );
  this.domElement.addEventListener( 'mousedown', onMouseDown, false );
  this.domElement.addEventListener( 'mousewheel', onMouseWheel, false );
  this.domElement.addEventListener( 'DOMMouseScroll', onMouseWheel, false ); // firefox
  this.domElement.addEventListener( 'keydown', onKeyDown, false);

};

THREE.OrbitControls.prototype = Object.create( THREE.EventDispatcher.prototype );