livecodingspace-app/support/proxy/vwf.example.com/scale-on-move.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 scale behavior (on move)
## 
## @name scale-on-click.vwf
## @namespace

--- 
extends:
  http://vwf.example.com/node3.vwf
properties:
  
  ## Scale rate
  ## 
  ## @name scale-on-move.vwf#scale-rate
  ## @property

  scale-rate: 0.14


events:
  valueChanged:

methods:

  ## Scale function. Updates component scale
  ## 
  ## @name scale-on-move.vwf#updateScale
  ## @function
  ##
  ## @returns undefined

  updateScale:

  ## Initialization function
  ## 
  ## @name scale-on-move.vwf#init
  ## @function
  ##
  ## @returns undefined

  init:

scripts:
- |
    this.init = function() {
      this.input = {
        "pointerInfo": undefined,
        "pickInfo": undefined,
        "previous": {
          "pointerInfo": undefined,
          "pickInfo": undefined,        
        },
        "pointerDown": {
          "pointerInfo": undefined,
          "pickInfo": undefined,        
        },
        "update": function( pointerInfo, pickInfo ){
          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.pointerDown = function( pointerInfo, pickInfo ) {
      if ( !this.input ) this.init();

      this.input.clear();

      this.input.pointerDown.pointerInfo = pointerInfo;
      this.input.pointerDown.pickInfo = pickInfo;

      this.worldTransOnDown = goog.vec.Mat4.createFromArray( this.parent.worldTransform );
      this.scaleOnDown = goog.vec.Vec3.createFromArray( this.parent.scale );
      this.mouseDownPos = goog.vec.Vec3.createFromArray( pickInfo.globalPosition );
      
      this.objectPos = goog.vec.Vec3.createFromValues( this.worldTransOnDown[12], this.worldTransOnDown[13], this.worldTransOnDown[14] );
      this.cameraPos = goog.vec.Vec3.createFromValues( pickInfo.globalSource[0], pickInfo.globalSource[1], pickInfo.globalSource[2] );

      // backwards?
      //this.objectVec3OnDown = goog.vec.Vec3.subtract( this.cameraPos, this.objectPos, goog.vec.Vec3.create() );
      //this.pointerVec3OnDown = goog.vec.Vec3.subtract( this.cameraPos, this.mouseDownPos, goog.vec.Vec3.create() );

      this.objectVec3OnDown = goog.vec.Vec3.subtract( this.objectPos, this.cameraPos, goog.vec.Vec3.create() );
      this.pointerVec3OnDown = goog.vec.Vec3.subtract( this.mouseDownPos, this.cameraPos, goog.vec.Vec3.create() );


      goog.vec.Vec3.normalize( this.objectVec3OnDown, this.objectVec3OnDown );
      goog.vec.Vec3.normalize( this.pointerVec3OnDown, this.pointerVec3OnDown );

      this.lastAngle = Math.acos( goog.vec.Vec3.dot( this.objectVec3OnDown, this.pointerVec3OnDown ) ) * (180 / Math.PI);

      // TO DO
      // if listAngle is very small then need to modify the 
      // scale rate, given this approach

      // TO DO      
      // also the distance to the object should be taken into consideration
      // the further away the object is, then the change in the angle
      // from the center doesn't change much when trying to decrease the scale
      
    }

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

    this.pointerMove = function( pointerInfo, pickInfo ) {
      this.input.update( pointerInfo, pickInfo );
      this.updateScale();
    }

    this.updateScale = function(){
      var currentScale = this.parent.scale; 
      var currentPointer = goog.vec.Vec3.createFromArray( this.input.pickInfo.pointerVector );
      goog.vec.Vec3.normalize( currentPointer, currentPointer );

      var currentAngle = Math.acos( goog.vec.Vec3.dot( this.objectVec3OnDown, currentPointer ) ) * (180 / Math.PI);

      if ( currentAngle > this.lastAngle ) {
       
        // moving away from the center 
        this.parent.scale = goog.vec.Vec3.add( currentScale, 
          goog.vec.Vec3.scale( 
            goog.vec.Vec3.createFromValues( 1, 1, 1 ), 
            ( currentAngle - this.lastAngle ) * this[ "scale-rate" ], 
            goog.vec.Vec3.create()
          ),          
        goog.vec.Vec3.create() );
        this.valueChanged( this.parent.scale );
        this.lastAngle = currentAngle;
      } else if ( currentAngle < this.lastAngle ){

        // moving towards from the center
        var newScale = goog.vec.Vec3.subtract( currentScale, 
          goog.vec.Vec3.scale( 
            goog.vec.Vec3.createFromValues( 1, 1, 1 ), 
            ( this.lastAngle - currentAngle ) * this[ "scale-rate" ], 
            goog.vec.Vec3.create()
          ),          
        goog.vec.Vec3.create() );
        
        // this needs to decrease more as the user 

        if ( goog.vec.Vec3.magnitude( newScale ) > 0 ) {
          this.parent.scale = newScale;
          this.valueChanged( this.parent.scale );
          this.lastAngle = currentAngle;
        }
      } 

    } //@ sourceURL=scale-on-move.vwf