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/* <copyright>
This file contains proprietary software owned by Motorola Mobility, Inc.<br/>
No rights, expressed or implied, whatsoever to this software are provided by Motorola Mobility, Inc. hereunder.<br/>
(c) Copyright 2011 Motorola Mobility, Inc. All Rights Reserved.
</copyright> */
///////////////////////////////////////////////////////////////////////
// Class ElementPlanes
// This class represents the 5 planes generated by an element
// in the world - the face itself, and one plane going back in Z
// for each side of the element. Lines drawn will clip against
// those 5 planes.
///////////////////////////////////////////////////////////////////////
var viewUtils = require("js/helper-classes/3D/view-utils").ViewUtils,
vecUtils = require("js/helper-classes/3D/vec-utils").VecUtils,
Rectangle = require("js/helper-classes/3D/rectangle").Rectangle;
var ElementPlanes = exports.ElementPlanes = Object.create(Object.prototype, {
///////////////////////////////////////////////////////////////////////
// Instance variables
///////////////////////////////////////////////////////////////////////
// maintain a back pointer to the original element
_elt: { value: null, writable: true },
// the 4 3D boundary points in world space
_boundaryPts: { value: null, writable: true },
// the 2D boundary rectangle. Used for quick rejection tests.
_rect: { value: null, writable: true },
_zMin: { value: 0, writable: true },
_zMax: { value: 0, writable: true },
// keep a flag indicating that the element is back facing
_backFacing: { value: false, writable: true },
// cache the normal
_planeEq: { value: null, writable: true },
///////////////////////////////////////////////////////////////////////
// Property accessors
///////////////////////////////////////////////////////////////////////
setElement: { value: function( elt ) { this._elt = elt; } },
getElement: { value: function() { return this._elt; } },
getPlaneEq: { value: function() { return this._planeEq.slice(0); } },
setPlaneEq: { value: function(p) { this._planeEq = p; } },
getRectangle: { value: function() { return this._rect; } },
getBoundaryPoints: { value: function() { return this._boundaryPts; } },
isBackFacing: { value: function() { return this._backFacing; } },
getZMin: { value: function() { return this._zMin; } },
getZMax: { value: function() { return this._zMax; } },
///////////////////////////////////////////////////////////////////////
// Methods
///////////////////////////////////////////////////////////////////////
init: {
value: function()
{
if (this._elt)
{
// get the 3D boundary points
var elt = this._elt;
this._boundaryPts = viewUtils.getElementViewBounds3D( elt );
//var mat = viewUtils.getMatrixFromElement( elt );
var tmpMat = viewUtils.getLocalToGlobalMatrix( elt );
for (var i=0; i<4; i++)
{
// this._boundaryPts[i] = viewUtils.localToGlobal(this._boundaryPts[i], elt );
this._boundaryPts[i] = viewUtils.localToGlobal2(this._boundaryPts[i], tmpMat);
}
// set the backfacing flag based on the direction of the normal
// for the purposes of stage drawing, we use a left-handed coordinate system
// (as opposed to the left-handed system used in the browser). With that
// assumption, the points are specified counterclockwise on the stage, producing
// a negative Z for the normal, hence a positive Z implies back facing.
var nrm = this.computeNormal();
this._backFacing = false;
if (nrm[2] > 0)
this._backFacing = true;
else
MathUtils.negate( nrm );
// create the plane equation
//var d = -( nrm.dot( this._boundaryPts[0]) );
var d = -vecUtils.vecDot(3, nrm, this._boundaryPts[0]);
var planeEq = [nrm[0], nrm[1], nrm[2], d] ;
this.setPlaneEq( planeEq );
// get the 2D rectangle
var rect = Object.create(Rectangle, {});
rect.setLeft( this._boundaryPts[0][0] );
rect.setTop( this._boundaryPts[0][1] );
rect.setRight( this._boundaryPts[0][0] );
rect.setBottom( this._boundaryPts[0][1] );
this._zMin = this._boundaryPts[0][2];
this._zMax = this._boundaryPts[0][2];
for (var i=1; i<4; i++)
{
rect.unionPoint( this._boundaryPts[i] );
var z = this._boundaryPts[i][2];
if (z < this._zMin) this._zMin = z;
if (z > this._zMax) this._zMax = z;
}
this._rect = rect;
}
}
},
computeNormal: {
value: function()
{
var xPts = new Array(), yPts = new Array(), zPts = new Array();
var n = this._boundaryPts.length;
for (var i=0; i<n; i++)
{
var pt = this._boundaryPts[i];
xPts.push( pt[0] );
yPts.push( pt[1] );
zPts.push( pt[2] );
}
var nrm = MathUtils.getPolygonNormal( n, xPts, yPts, zPts );
return nrm;
}
}
});
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