livecodingspace-app/support/proxy/vwf.example.com/planarDrag.vwf.yaml

# Copyright 2012 United States Government, as represented by the Secretary of Defense, Under
# Secretary of Defense (Personnel & Readiness).
# 
# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
# in compliance with the License. You may obtain a copy of the License at
# 
#   http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software distributed under the License
# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
# or implied. See the License for the specific language governing permissions and limitations under
# the License.

## The component representation of a control behavior
## 
## @name control.vwf
## @namespace

---
methods:
  mouseInit:
  linePlaneIntersection: 
events:
  pointerDown:
  pointerMove:
  pointerUp:
scripts:
- |
  this.initialize = function() {
    this.planeNormal = undefined;
    this.planePoint = undefined;
    this.cameraTranslation = undefined;
    this.pointerVector = goog.vec.Vec3.create();
  }
  // Sets up the mouse pointer information used for dragging.
  this.mouseInit = function() {
    this.input = {
      "pointerInfo": undefined,
      "pickInfo": undefined,
      "previous": {
        "pointerInfo": undefined,
        "pickInfo": undefined,        
      },
      update: function( pointerInfo, pickInfo ){
        if(!this.previous.pointerInfo) {
          this.previous.pointerInfo = this.pointerInfo;
          this.previous.pickInfo = this.pickInfo;
        }
        this.pointerInfo = pointerInfo;
        this.pickInfo = pickInfo;
      }, 
      clear: function(){
        this.previous.pointerInfo = undefined;
        this.previous.pickInfo = undefined;
        this.pointerInfo = undefined;
        this.pickInfo = undefined;        
      },
      change: function() {
        var ret = [ 0, 0 ]
        if ( this.pointerInfo && this.previous.pointerInfo ) {
          ret[0] = this.pointerInfo.position[0] - this.previous.pointerInfo.position[0];
          ret[1] = this.pointerInfo.position[1] - this.previous.pointerInfo.position[1];
        }
        return ret;
      }
    };
  }
  

  this.linePlaneIntersection = function( planePoint, planeNormal, linePoint, lineVec ){
 
    var intersection, dotNumerator, dotDenominator;
    var vector = goog.vec.Vec3.create();
 
    //calculate the distance between the linePoint and the line-plane intersection point
    var temp = goog.vec.Vec3.create();
    
    goog.vec.Vec3.subtract( planePoint, linePoint, temp );
    dotNumerator = goog.vec.Vec3.dot( temp, planeNormal );
    dotDenominator = goog.vec.Vec3.dot( lineVec, planeNormal );
 
    //line and plane are not parallel
    if( dotDenominator != 0.0 ){
      intersection = goog.vec.Vec3.create();

      //create a vector from the linePoint to the intersection point
      goog.vec.Vec3.scale( lineVec, dotNumerator / dotDenominator, vector );
 
      //get the coordinates of the line-plane intersection point
      goog.vec.Vec3.add( linePoint, vector, intersection );  
    }
    return intersection;
  }


  this.pointerDown = function( pointerInfo, pickInfo ) {
    if ( this.input === undefined ) this.mouseInit();
    this.input.clear();
    this.input.pointerInfo = pointerInfo;
    this.input.pickInfo = pickInfo;

    this.planeNormal = goog.vec.Vec3.createFloat32FromArray( pickInfo.globalNormal );
    this.planePoint = goog.vec.Vec3.createFloat32FromArray( pickInfo.globalPosition ); 
    this.cameraTranslation = goog.vec.Vec3.createFloat32FromArray( pickInfo.globalSource );
    goog.vec.Vec3.subtract( this.planePoint, this.cameraTranslation, this.pointerVector );
  }

  this.pointerUp = function( pointerInfo, pickInfo ) {
    this.input.clear();
  }

  this.pointerMove = function( pointerInfo, pickInfo ) {
    
    // update the camera location and the view vector
    this.cameraTranslation = goog.vec.Vec3.createFloat32FromArray( pickInfo.globalSource );
    
    // we need a way of getting the pointerVector here without the using the 
    // globalPosition, because that might not have a value
    
    if ( pickInfo.pointerVector ) {
      this.pointerVector = goog.vec.Vec3.createFloat32FromArray( pickInfo.pointerVector );
    } else {
      var hitPoint = goog.vec.Vec3.createFloat32FromArray( pickInfo.globalPosition );
      goog.vec.Vec3.subtract( hitPoint, this.cameraTranslation, this.pointerVector );
      goog.vec.Vec3.normalize( this.pointerVector, this.pointerVector );
    }

    var newPlaneIntersection = this.linePlaneIntersection( this.planePoint, 
              this.planeNormal, this.cameraTranslation, this.pointerVector );
    if ( newPlaneIntersection !== undefined ) {
      var translation = goog.vec.Vec3.createFloat32FromArray( this.parent.translation );
      var diff = goog.vec.Vec3.create();
      goog.vec.Vec3.subtract( newPlaneIntersection, this.planePoint, diff );
      this.parent.translation = goog.vec.Vec3.add( translation, diff, goog.vec.Vec3.create() );
      this.planePoint = goog.vec.Vec3.clone( newPlaneIntersection );
    }

    this.input.previous.pointerInfo = pointerInfo;
    this.input.previous.pickInfo = pickInfo;
  } //@ sourceURL=planarDrag.vwf