text: /**
   * @fileoverview This class can be used to subdivide a convex Geometry object into pieces.
   *
   * Usage:
   *
   * Use the function prepareBreakableObject to prepare a Mesh object to be broken.
   *
   * Then, call the various functions to subdivide the object (subdivideByImpact, cutByPlane)
   *
   * Sub-objects that are product of subdivision don't need prepareBreakableObject to be called on them.
   *
   * Requisites for the object:
   *
   *  - Mesh object must have a BufferGeometry (not Geometry) and a Material
   *
   *  - Vertex normals must be planar (not smoothed)
   *
   *  - The geometry must be convex (this is not checked in the library). You can create convex
   *  geometries with THREE.ConvexGeometry. The BoxBufferGeometry, SphereBufferGeometry and other convex primitives
   *  can also be used.
   *
   * Note: This lib adds member variables to object's userData member (see prepareBreakableObject function)
   * Use with caution and read the code when using with other libs.
   *
   * @param {double} minSizeForBreak Min size a debris can have to break.
   * @param {double} smallDelta Max distance to consider that a point belongs to a plane.
   *
  */
  
  THREE.ConvexObjectBreaker = function ( minSizeForBreak, smallDelta ) {
  
  	this.minSizeForBreak = minSizeForBreak || 1.4;
  	this.smallDelta = smallDelta || 0.0001;
  
  	this.tempLine1 = new THREE.Line3();
  	this.tempPlane1 = new THREE.Plane();
  	this.tempPlane2 = new THREE.Plane();
  	this.tempPlane_Cut = new THREE.Plane();
  	this.tempCM1 = new THREE.Vector3();
  	this.tempCM2 = new THREE.Vector3();
  	this.tempVector3 = new THREE.Vector3();
  	this.tempVector3_2 = new THREE.Vector3();
  	this.tempVector3_3 = new THREE.Vector3();
  	this.tempVector3_P0 = new THREE.Vector3();
  	this.tempVector3_P1 = new THREE.Vector3();
  	this.tempVector3_P2 = new THREE.Vector3();
  	this.tempVector3_N0 = new THREE.Vector3();
  	this.tempVector3_N1 = new THREE.Vector3();
  	this.tempVector3_AB = new THREE.Vector3();
  	this.tempVector3_CB = new THREE.Vector3();
  	this.tempResultObjects = { object1: null, object2: null };
  
  	this.segments = [];
  	var n = 30 * 30;
  	for ( var i = 0; i < n; i ++ ) this.segments[ i ] = false;
  
  };
  
  THREE.ConvexObjectBreaker.prototype = {
  
  	constructor: THREE.ConvexObjectBreaker,
  
  	prepareBreakableObject: function ( object, mass, velocity, angularVelocity, breakable ) {
  
  		// object is a THREE.Object3d (normally a Mesh), must have a BufferGeometry, and it must be convex.
  		// Its material property is propagated to its children (sub-pieces)
  		// mass must be > 0
  
  		if ( ! object.geometry.isBufferGeometry ) {
  
  			console.error( 'THREE.ConvexObjectBreaker.prepareBreakableObject(): Parameter object must have a BufferGeometry.' );
  
  		}
  
  		var userData = object.userData;
  		userData.mass = mass;
  		userData.velocity = velocity.clone();
  		userData.angularVelocity = angularVelocity.clone();
  		userData.breakable = breakable;
  
  	},
  
  	/*
  	 * @param {int} maxRadialIterations Iterations for radial cuts.
  	 * @param {int} maxRandomIterations Max random iterations for not-radial cuts
  	 *
  	 * Returns the array of pieces
  	 */
  	subdivideByImpact: function ( object, pointOfImpact, normal, maxRadialIterations, maxRandomIterations ) {
  
  		var debris = [];
  
  		var tempPlane1 = this.tempPlane1;
  		var tempPlane2 = this.tempPlane2;
  
  		this.tempVector3.addVectors( pointOfImpact, normal );
  		tempPlane1.setFromCoplanarPoints( pointOfImpact, object.position, this.tempVector3 );
  
  		var maxTotalIterations = maxRandomIterations + maxRadialIterations;
  
  		var scope = this;
  
  		function subdivideRadial( subObject, startAngle, endAngle, numIterations ) {
  
  			if ( Math.random() < numIterations * 0.05 || numIterations > maxTotalIterations ) {
  
  				debris.push( subObject );
  
  				return;
  
  			}
  
  			var angle = Math.PI;
  
  			if ( numIterations === 0 ) {
  
  				tempPlane2.normal.copy( tempPlane1.normal );
  				tempPlane2.constant = tempPlane1.constant;
  
  			} else {
  
  				if ( numIterations <= maxRadialIterations ) {
  
  					angle = ( endAngle - startAngle ) * ( 0.2 + 0.6 * Math.random() ) + startAngle;
  
  					// Rotate tempPlane2 at impact point around normal axis and the angle
  					scope.tempVector3_2.copy( object.position ).sub( pointOfImpact ).applyAxisAngle( normal, angle ).add( pointOfImpact );
  					tempPlane2.setFromCoplanarPoints( pointOfImpact, scope.tempVector3, scope.tempVector3_2 );
  
  				} else {
  
  					angle = ( ( 0.5 * ( numIterations & 1 ) ) + 0.2 * ( 2 - Math.random() ) ) * Math.PI;
  
  					// Rotate tempPlane2 at object position around normal axis and the angle
  					scope.tempVector3_2.copy( pointOfImpact ).sub( subObject.position ).applyAxisAngle( normal, angle ).add( subObject.position );
  					scope.tempVector3_3.copy( normal ).add( subObject.position );
  					tempPlane2.setFromCoplanarPoints( subObject.position, scope.tempVector3_3, scope.tempVector3_2 );
  
  				}
  
  			}
  
  			// Perform the cut
  			scope.cutByPlane( subObject, tempPlane2, scope.tempResultObjects );
  
  			var obj1 = scope.tempResultObjects.object1;
  			var obj2 = scope.tempResultObjects.object2;
  
  			if ( obj1 ) {
  
  				subdivideRadial( obj1, startAngle, angle, numIterations + 1 );
  
  			}
  
  			if ( obj2 ) {
  
  				subdivideRadial( obj2, angle, endAngle, numIterations + 1 );
  
  			}
  
  		}
  
  		subdivideRadial( object, 0, 2 * Math.PI, 0 );
  
  		return debris;
  
  	},
  
  	cutByPlane: function ( object, plane, output ) {
  
  		// Returns breakable objects in output.object1 and output.object2 members, the resulting 2 pieces of the cut.
  		// object2 can be null if the plane doesn't cut the object.
  		// object1 can be null only in case of internal error
  		// Returned value is number of pieces, 0 for error.
  
  		var geometry = object.geometry;
  		var coords = geometry.attributes.position.array;
  		var normals = geometry.attributes.normal.array;
  
  		var numPoints = coords.length / 3;
  		var numFaces = numPoints / 3;
  
  		var indices = geometry.getIndex();
  
  		if ( indices ) {
  
  			indices = indices.array;
  			numFaces = indices.length / 3;
  
  		}
  
  		function getVertexIndex( faceIdx, vert ) {
  
  			// vert = 0, 1 or 2.
  
  			var idx = faceIdx * 3 + vert;
  
  			return indices ? indices[ idx ] : idx;
  
  		}
  
  		var points1 = [];
  		var points2 = [];
  
  		var delta = this.smallDelta;
  
  		// Reset segments mark
  		var numPointPairs = numPoints * numPoints;
  		for ( var i = 0; i < numPointPairs; i ++ ) this.segments[ i ] = false;
  
  		var p0 = this.tempVector3_P0;
  		var p1 = this.tempVector3_P1;
  		var n0 = this.tempVector3_N0;
  		var n1 = this.tempVector3_N1;
  
  		// Iterate through the faces to mark edges shared by coplanar faces
  		for ( var i = 0; i < numFaces - 1; i ++ ) {
  
  			var a1 = getVertexIndex( i, 0 );
  			var b1 = getVertexIndex( i, 1 );
  			var c1 = getVertexIndex( i, 2 );
  
  			// Assuming all 3 vertices have the same normal
  			n0.set( normals[ a1 ], normals[ a1 ] + 1, normals[ a1 ] + 2 );
  
  			for ( var j = i + 1; j < numFaces; j ++ ) {
  
  				var a2 = getVertexIndex( j, 0 );
  				var b2 = getVertexIndex( j, 1 );
  				var c2 = getVertexIndex( j, 2 );
  
  				// Assuming all 3 vertices have the same normal
  				n1.set( normals[ a2 ], normals[ a2 ] + 1, normals[ a2 ] + 2 );
  
  				var coplanar = 1 - n0.dot( n1 ) < delta;
  
  				if ( coplanar ) {
  
  					if ( a1 === a2 || a1 === b2 || a1 === c2 ) {
  
  						if ( b1 === a2 || b1 === b2 || b1 === c2 ) {
  
  							this.segments[ a1 * numPoints + b1 ] = true;
  							this.segments[ b1 * numPoints + a1 ] = true;
  
  						}	else {
  
  							this.segments[ c1 * numPoints + a1 ] = true;
  							this.segments[ a1 * numPoints + c1 ] = true;
  
  						}
  
  					}	else if ( b1 === a2 || b1 === b2 || b1 === c2 ) {
  
  						this.segments[ c1 * numPoints + b1 ] = true;
  						this.segments[ b1 * numPoints + c1 ] = true;
  
  					}
  
  				}
  
  			}
  
  		}
  
  		// Transform the plane to object local space
  		var localPlane = this.tempPlane_Cut;
  		object.updateMatrix();
  		THREE.ConvexObjectBreaker.transformPlaneToLocalSpace( plane, object.matrix, localPlane );
  
  		// Iterate through the faces adding points to both pieces
  		for ( var i = 0; i < numFaces; i ++ ) {
  
  			var va = getVertexIndex( i, 0 );
  			var vb = getVertexIndex( i, 1 );
  			var vc = getVertexIndex( i, 2 );
  
  			for ( var segment = 0; segment < 3; segment ++ ) {
  
  				var i0 = segment === 0 ? va : ( segment === 1 ? vb : vc );
  				var i1 = segment === 0 ? vb : ( segment === 1 ? vc : va );
  
  				var segmentState = this.segments[ i0 * numPoints + i1 ];
  
  				if ( segmentState ) continue; // The segment already has been processed in another face
  
  				// Mark segment as processed (also inverted segment)
  				this.segments[ i0 * numPoints + i1 ] = true;
  				this.segments[ i1 * numPoints + i0 ] = true;
  
  				p0.set( coords[ 3 * i0 ], coords[ 3 * i0 + 1 ], coords[ 3 * i0 + 2 ] );
  				p1.set( coords[ 3 * i1 ], coords[ 3 * i1 + 1 ], coords[ 3 * i1 + 2 ] );
  
  				// mark: 1 for negative side, 2 for positive side, 3 for coplanar point
  				var mark0 = 0;
  
  				var d = localPlane.distanceToPoint( p0 );
  
  				if ( d > delta ) {
  
  					mark0 = 2;
  					points2.push( p0.clone() );
  
  				} else if ( d < - delta ) {
  
  					mark0 = 1;
  					points1.push( p0.clone() );
  
  				} else {
  
  					mark0 = 3;
  					points1.push( p0.clone() );
  					points2.push( p0.clone() );
  
  				}
  
  				// mark: 1 for negative side, 2 for positive side, 3 for coplanar point
  				var mark1 = 0;
  
  				var d = localPlane.distanceToPoint( p1 );
  
  				if ( d > delta ) {
  
  					mark1 = 2;
  					points2.push( p1.clone() );
  
  				} else if ( d < - delta ) {
  
  					mark1 = 1;
  					points1.push( p1.clone() );
  
  				}	else {
  
  					mark1 = 3;
  					points1.push( p1.clone() );
  					points2.push( p1.clone() );
  
  				}
  
  				if ( ( mark0 === 1 && mark1 === 2 ) || ( mark0 === 2 && mark1 === 1 ) ) {
  
  					// Intersection of segment with the plane
  
  					this.tempLine1.start.copy( p0 );
  					this.tempLine1.end.copy( p1 );
  
  					var intersection = new THREE.Vector3();
  					intersection = localPlane.intersectLine( this.tempLine1, intersection );
  
  					if ( intersection === undefined ) {
  
  						// Shouldn't happen
  						console.error( 'Internal error: segment does not intersect plane.' );
  						output.segmentedObject1 = null;
  						output.segmentedObject2 = null;
  						return 0;
  
  					}
  
  					points1.push( intersection );
  					points2.push( intersection.clone() );
  
  				}
  
  			}
  
  		}
  
  		// Calculate debris mass (very fast and imprecise):
  		var newMass = object.userData.mass * 0.5;
  
  		// Calculate debris Center of Mass (again fast and imprecise)
  		this.tempCM1.set( 0, 0, 0 );
  		var radius1 = 0;
  		var numPoints1 = points1.length;
  
  		if ( numPoints1 > 0 ) {
  
  			for ( var i = 0; i < numPoints1; i ++ ) this.tempCM1.add( points1[ i ] );
  
  			this.tempCM1.divideScalar( numPoints1 );
  			for ( var i = 0; i < numPoints1; i ++ ) {
  
  				var p = points1[ i ];
  				p.sub( this.tempCM1 );
  				radius1 = Math.max( radius1, p.x, p.y, p.z );
  
  			}
  
  			this.tempCM1.add( object.position );
  
  		}
  
  		this.tempCM2.set( 0, 0, 0 );
  		var radius2 = 0;
  		var numPoints2 = points2.length;
  		if ( numPoints2 > 0 ) {
  
  			for ( var i = 0; i < numPoints2; i ++ ) this.tempCM2.add( points2[ i ] );
  
  			this.tempCM2.divideScalar( numPoints2 );
  			for ( var i = 0; i < numPoints2; i ++ ) {
  
  				var p = points2[ i ];
  				p.sub( this.tempCM2 );
  				radius2 = Math.max( radius2, p.x, p.y, p.z );
  
  			}
  
  			this.tempCM2.add( object.position );
  
  		}
  
  		var object1 = null;
  		var object2 = null;
  
  		var numObjects = 0;
  
  		if ( numPoints1 > 4 ) {
  
  			object1 = new THREE.Mesh( new THREE.ConvexGeometry( points1 ), object.material );
  			object1.position.copy( this.tempCM1 );
  			object1.quaternion.copy( object.quaternion );
  
  			this.prepareBreakableObject( object1, newMass, object.userData.velocity, object.userData.angularVelocity, 2 * radius1 > this.minSizeForBreak );
  
  			numObjects ++;
  
  		}
  
  		if ( numPoints2 > 4 ) {
  
  			object2 = new THREE.Mesh( new THREE.ConvexGeometry( points2 ), object.material );
  			object2.position.copy( this.tempCM2 );
  			object2.quaternion.copy( object.quaternion );
  
  			this.prepareBreakableObject( object2, newMass, object.userData.velocity, object.userData.angularVelocity, 2 * radius2 > this.minSizeForBreak );
  
  			numObjects ++;
  
  		}
  
  		output.object1 = object1;
  		output.object2 = object2;
  
  		return numObjects;
  
  	}
  
  };
  
  THREE.ConvexObjectBreaker.transformFreeVector = function ( v, m ) {
  
  	// input:
  	// vector interpreted as a free vector
  	// THREE.Matrix4 orthogonal matrix (matrix without scale)
  
  	var x = v.x, y = v.y, z = v.z;
  	var e = m.elements;
  
  	v.x = e[ 0 ] * x + e[ 4 ] * y + e[ 8 ] * z;
  	v.y = e[ 1 ] * x + e[ 5 ] * y + e[ 9 ] * z;
  	v.z = e[ 2 ] * x + e[ 6 ] * y + e[ 10 ] * z;
  
  	return v;
  
  };
  
  THREE.ConvexObjectBreaker.transformFreeVectorInverse = function ( v, m ) {
  
  	// input:
  	// vector interpreted as a free vector
  	// THREE.Matrix4 orthogonal matrix (matrix without scale)
  
  	var x = v.x, y = v.y, z = v.z;
  	var e = m.elements;
  
  	v.x = e[ 0 ] * x + e[ 1 ] * y + e[ 2 ] * z;
  	v.y = e[ 4 ] * x + e[ 5 ] * y + e[ 6 ] * z;
  	v.z = e[ 8 ] * x + e[ 9 ] * y + e[ 10 ] * z;
  
  	return v;
  
  };
  
  THREE.ConvexObjectBreaker.transformTiedVectorInverse = function ( v, m ) {
  
  	// input:
  	// vector interpreted as a tied (ordinary) vector
  	// THREE.Matrix4 orthogonal matrix (matrix without scale)
  
  	var x = v.x, y = v.y, z = v.z;
  	var e = m.elements;
  
  	v.x = e[ 0 ] * x + e[ 1 ] * y + e[ 2 ] * z - e[ 12 ];
  	v.y = e[ 4 ] * x + e[ 5 ] * y + e[ 6 ] * z - e[ 13 ];
  	v.z = e[ 8 ] * x + e[ 9 ] * y + e[ 10 ] * z - e[ 14 ];
  
  	return v;
  
  };
  
  THREE.ConvexObjectBreaker.transformPlaneToLocalSpace = function () {
  
  	var v1 = new THREE.Vector3();
  
  	return function transformPlaneToLocalSpace( plane, m, resultPlane ) {
  
  		resultPlane.normal.copy( plane.normal );
  		resultPlane.constant = plane.constant;
  
  		var referencePoint = THREE.ConvexObjectBreaker.transformTiedVectorInverse( plane.coplanarPoint( v1 ), m );
  
  		THREE.ConvexObjectBreaker.transformFreeVectorInverse( resultPlane.normal, m );
  
  		// recalculate constant (like in setFromNormalAndCoplanarPoint)
  		resultPlane.constant = - referencePoint.dot( resultPlane.normal );
  
  
  	};
  
  }();
  