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/* <copyright>
Copyright (c) 2012, Motorola Mobility, Inc
All Rights Reserved.
BSD License.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of Motorola Mobility nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
</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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