three.js/src/math/Frustum.js

/**
 * @author mrdoob / http://mrdoob.com/
 * @author alteredq / http://alteredqualia.com/
 * @author bhouston / http://exocortex.com
 */

THREE.Frustum = function ( p0, p1, p2, p3, p4, p5 ) {

	this.planes = [

		( p0 !== undefined ) ? p0 : new THREE.Plane(),
		( p1 !== undefined ) ? p1 : new THREE.Plane(),
		( p2 !== undefined ) ? p2 : new THREE.Plane(),
		( p3 !== undefined ) ? p3 : new THREE.Plane(),
		( p4 !== undefined ) ? p4 : new THREE.Plane(),
		( p5 !== undefined ) ? p5 : new THREE.Plane()

	];

};

THREE.Frustum.prototype = {

	constructor: THREE.Frustum,

	set: function ( p0, p1, p2, p3, p4, p5 ) {

		var planes = this.planes;

		planes[0].copy( p0 );
		planes[1].copy( p1 );
		planes[2].copy( p2 );
		planes[3].copy( p3 );
		planes[4].copy( p4 );
		planes[5].copy( p5 );

		return this;

	},

	copy: function ( frustum ) {

		var planes = this.planes;

		for( var i = 0; i < 6; i ++ ) {

			planes[i].copy( frustum.planes[i] );

		}

		return this;

	},

	setFromMatrix: function ( m ) {

		var planes = this.planes;
		var me = m.elements;
		var me0 = me[0], me1 = me[1], me2 = me[2], me3 = me[3];
		var me4 = me[4], me5 = me[5], me6 = me[6], me7 = me[7];
		var me8 = me[8], me9 = me[9], me10 = me[10], me11 = me[11];
		var me12 = me[12], me13 = me[13], me14 = me[14], me15 = me[15];

		planes[ 0 ].setComponents( me3 - me0, me7 - me4, me11 - me8, me15 - me12 ).normalize();
		planes[ 1 ].setComponents( me3 + me0, me7 + me4, me11 + me8, me15 + me12 ).normalize();
		planes[ 2 ].setComponents( me3 + me1, me7 + me5, me11 + me9, me15 + me13 ).normalize();
		planes[ 3 ].setComponents( me3 - me1, me7 - me5, me11 - me9, me15 - me13 ).normalize();
		planes[ 4 ].setComponents( me3 - me2, me7 - me6, me11 - me10, me15 - me14 ).normalize();
		planes[ 5 ].setComponents( me3 + me2, me7 + me6, me11 + me10, me15 + me14 ).normalize();

		return this;

	},

	intersectsObject: function () {

		var center = new THREE.Vector3();

		return function ( object ) {

			// this method is expanded inlined for performance reasons.

			var geometry = object.geometry;
			var matrix = object.matrixWorld;

			if ( geometry.boundingSphere === null ) geometry.computeBoundingSphere();

			var negRadius = - geometry.boundingSphere.radius * matrix.getMaxScaleOnAxis();

			center.getPositionFromMatrix( matrix );

			var planes = this.planes;

			for ( var i = 0; i < 6; i ++ ) {

				var distance = planes[ i ].distanceToPoint( center );

				if ( distance < negRadius ) {

					return false;

				}

			}

			return true;

		};

	}(),

	intersectsSphere: function ( sphere ) {

		var planes = this.planes;
		var center = sphere.center;
		var negRadius = -sphere.radius;

		for ( var i = 0; i < 6; i ++ ) {

			var distance = planes[ i ].distanceToPoint( center );

			if ( distance < negRadius ) {

				return false;

			}

		}

		return true;

	},

	intersectsBox : function() {

		var p1 = new THREE.Vector3(),
			p2 = new THREE.Vector3();

		return function( box ) {

			var planes = this.planes;
			
			for ( var i = 0; i < 6 ; i ++ ) {
			
				var plane = planes[i];
				
				p1.x = plane.normal.x > 0 ? box.min.x : box.max.x;
				p2.x = plane.normal.x > 0 ? box.max.x : box.min.x;
				p1.y = plane.normal.y > 0 ? box.min.y : box.max.y;
				p2.y = plane.normal.y > 0 ? box.max.y : box.min.y;
				p1.z = plane.normal.z > 0 ? box.min.z : box.max.z;
				p2.z = plane.normal.z > 0 ? box.max.z : box.min.z;

				var d1 = plane.distanceToPoint( p1 );
				var d2 = plane.distanceToPoint( p2 );
				
				// if both outside plane, no intersection

				if ( d1 < 0 && d2 < 0 ) {
					
					return false;
		
				}
			}

			return true;
		};

	}(),


	containsPoint: function ( point ) {

		var planes = this.planes;

		for ( var i = 0; i < 6; i ++ ) {

			if ( planes[ i ].distanceToPoint( point ) < 0 ) {

				return false;

			}

		}

		return true;

	},

	clone: function () {

		return new THREE.Frustum().copy( this );

	}

};