three.js/src/math/Box3.js

import { Vector3 } from './Vector3.js';
import { Sphere } from './Sphere.js';

/**
 * @author bhouston / http://clara.io
 * @author WestLangley / http://github.com/WestLangley
 */

function Box3( min, max ) {

	this.min = ( min !== undefined ) ? min : new Vector3( + Infinity, + Infinity, + Infinity );
	this.max = ( max !== undefined ) ? max : new Vector3( - Infinity, - Infinity, - Infinity );

}

Object.assign( Box3.prototype, {

	isBox3: true,

	set: function ( min, max ) {

		this.min.copy( min );
		this.max.copy( max );

		return this;

	},

	setFromArray: function ( array ) {

		var minX = + Infinity;
		var minY = + Infinity;
		var minZ = + Infinity;

		var maxX = - Infinity;
		var maxY = - Infinity;
		var maxZ = - Infinity;

		for ( var i = 0, l = array.length; i < l; i += 3 ) {

			var x = array[ i ];
			var y = array[ i + 1 ];
			var z = array[ i + 2 ];

			if ( x < minX ) minX = x;
			if ( y < minY ) minY = y;
			if ( z < minZ ) minZ = z;

			if ( x > maxX ) maxX = x;
			if ( y > maxY ) maxY = y;
			if ( z > maxZ ) maxZ = z;

		}

		this.min.set( minX, minY, minZ );
		this.max.set( maxX, maxY, maxZ );

		return this;

	},

	setFromBufferAttribute: function ( attribute ) {

		var minX = + Infinity;
		var minY = + Infinity;
		var minZ = + Infinity;

		var maxX = - Infinity;
		var maxY = - Infinity;
		var maxZ = - Infinity;

		for ( var i = 0, l = attribute.count; i < l; i ++ ) {

			var x = attribute.getX( i );
			var y = attribute.getY( i );
			var z = attribute.getZ( i );

			if ( x < minX ) minX = x;
			if ( y < minY ) minY = y;
			if ( z < minZ ) minZ = z;

			if ( x > maxX ) maxX = x;
			if ( y > maxY ) maxY = y;
			if ( z > maxZ ) maxZ = z;

		}

		this.min.set( minX, minY, minZ );
		this.max.set( maxX, maxY, maxZ );

		return this;

	},

	setFromPoints: function ( points ) {

		this.makeEmpty();

		for ( var i = 0, il = points.length; i < il; i ++ ) {

			this.expandByPoint( points[ i ] );

		}

		return this;

	},

	setFromCenterAndSize: function () {

		var v1 = new Vector3();

		return function setFromCenterAndSize( center, size ) {

			var halfSize = v1.copy( size ).multiplyScalar( 0.5 );

			this.min.copy( center ).sub( halfSize );
			this.max.copy( center ).add( halfSize );

			return this;

		};

	}(),

	setFromObject: function ( object ) {

		this.makeEmpty();

		return this.expandByObject( object );

	},

	clone: function () {

		return new this.constructor().copy( this );

	},

	copy: function ( box ) {

		this.min.copy( box.min );
		this.max.copy( box.max );

		return this;

	},

	makeEmpty: function () {

		this.min.x = this.min.y = this.min.z = + Infinity;
		this.max.x = this.max.y = this.max.z = - Infinity;

		return this;

	},

	isEmpty: function () {

		// this is a more robust check for empty than ( volume <= 0 ) because volume can get positive with two negative axes

		return ( this.max.x < this.min.x ) || ( this.max.y < this.min.y ) || ( this.max.z < this.min.z );

	},

	getCenter: function ( optionalTarget ) {

		var result = optionalTarget || new Vector3();
		return this.isEmpty() ? result.set( 0, 0, 0 ) : result.addVectors( this.min, this.max ).multiplyScalar( 0.5 );

	},

	getSize: function ( optionalTarget ) {

		var result = optionalTarget || new Vector3();
		return this.isEmpty() ? result.set( 0, 0, 0 ) : result.subVectors( this.max, this.min );

	},

	expandByPoint: function ( point ) {

		this.min.min( point );
		this.max.max( point );

		return this;

	},

	expandByVector: function ( vector ) {

		this.min.sub( vector );
		this.max.add( vector );

		return this;

	},

	expandByScalar: function ( scalar ) {

		this.min.addScalar( - scalar );
		this.max.addScalar( scalar );

		return this;

	},

	expandByObject: function () {

		// Computes the world-axis-aligned bounding box of an object (including its children),
		// accounting for both the object's, and children's, world transforms

		var scope, i, l;

		var v1 = new Vector3();

		function traverse( node ) {

			var geometry = node.geometry;

			if ( geometry !== undefined ) {

				if ( geometry.isGeometry ) {

					var vertices = geometry.vertices;

					for ( i = 0, l = vertices.length; i < l; i ++ ) {

						v1.copy( vertices[ i ] );
						v1.applyMatrix4( node.matrixWorld );

						scope.expandByPoint( v1 );

					}

				} else if ( geometry.isBufferGeometry ) {

					var attribute = geometry.attributes.position;

					if ( attribute !== undefined ) {

						for ( i = 0, l = attribute.count; i < l; i ++ ) {

							v1.fromBufferAttribute( attribute, i ).applyMatrix4( node.matrixWorld );

							scope.expandByPoint( v1 );

						}

					}

				}

			}

		}

		return function expandByObject( object ) {

			scope = this;

			object.updateMatrixWorld( true );

			object.traverse( traverse );

			return this;

		};

	}(),

	containsPoint: function ( point ) {

		return point.x < this.min.x || point.x > this.max.x ||
			point.y < this.min.y || point.y > this.max.y ||
			point.z < this.min.z || point.z > this.max.z ? false : true;

	},

	containsBox: function ( box ) {

		return this.min.x <= box.min.x && box.max.x <= this.max.x &&
			this.min.y <= box.min.y && box.max.y <= this.max.y &&
			this.min.z <= box.min.z && box.max.z <= this.max.z;

	},

	getParameter: function ( point, optionalTarget ) {

		// This can potentially have a divide by zero if the box
		// has a size dimension of 0.

		var result = optionalTarget || new Vector3();

		return result.set(
			( point.x - this.min.x ) / ( this.max.x - this.min.x ),
			( point.y - this.min.y ) / ( this.max.y - this.min.y ),
			( point.z - this.min.z ) / ( this.max.z - this.min.z )
		);

	},

	intersectsBox: function ( box ) {

		// using 6 splitting planes to rule out intersections.
		return box.max.x < this.min.x || box.min.x > this.max.x ||
			box.max.y < this.min.y || box.min.y > this.max.y ||
			box.max.z < this.min.z || box.min.z > this.max.z ? false : true;

	},

	intersectsSphere: ( function () {

		var closestPoint = new Vector3();

		return function intersectsSphere( sphere ) {

			// Find the point on the AABB closest to the sphere center.
			this.clampPoint( sphere.center, closestPoint );

			// If that point is inside the sphere, the AABB and sphere intersect.
			return closestPoint.distanceToSquared( sphere.center ) <= ( sphere.radius * sphere.radius );

		};

	} )(),

	intersectsPlane: function ( plane ) {

		// We compute the minimum and maximum dot product values. If those values
		// are on the same side (back or front) of the plane, then there is no intersection.

		var min, max;

		if ( plane.normal.x > 0 ) {

			min = plane.normal.x * this.min.x;
			max = plane.normal.x * this.max.x;

		} else {

			min = plane.normal.x * this.max.x;
			max = plane.normal.x * this.min.x;

		}

		if ( plane.normal.y > 0 ) {

			min += plane.normal.y * this.min.y;
			max += plane.normal.y * this.max.y;

		} else {

			min += plane.normal.y * this.max.y;
			max += plane.normal.y * this.min.y;

		}

		if ( plane.normal.z > 0 ) {

			min += plane.normal.z * this.min.z;
			max += plane.normal.z * this.max.z;

		} else {

			min += plane.normal.z * this.max.z;
			max += plane.normal.z * this.min.z;

		}

		return ( min <= plane.constant && max >= plane.constant );

	},

	intersectsTriangle: ( function () {

		// triangle centered vertices
		var v0 = new Vector3();
		var v1 = new Vector3();
		var v2 = new Vector3();

		// triangle edge vectors
		var f0 = new Vector3();
		var f1 = new Vector3();
		var f2 = new Vector3();

		var testAxis = new Vector3();

		var center = new Vector3();
		var extents = new Vector3();

		var triangleNormal = new Vector3();

		function satForAxes( axes ) {

			var i, j;

			for ( i = 0, j = axes.length - 3; i <= j; i += 3 ) {

				testAxis.fromArray( axes, i );
				// project the aabb onto the seperating axis
				var r = extents.x * Math.abs( testAxis.x ) + extents.y * Math.abs( testAxis.y ) + extents.z * Math.abs( testAxis.z );
				// project all 3 vertices of the triangle onto the seperating axis
				var p0 = v0.dot( testAxis );
				var p1 = v1.dot( testAxis );
				var p2 = v2.dot( testAxis );
				// actual test, basically see if either of the most extreme of the triangle points intersects r
				if ( Math.max( - Math.max( p0, p1, p2 ), Math.min( p0, p1, p2 ) ) > r ) {

					// points of the projected triangle are outside the projected half-length of the aabb
					// the axis is seperating and we can exit
					return false;

				}

			}

			return true;

		}

		return function intersectsTriangle( triangle ) {

			if ( this.isEmpty() ) {

				return false;

			}

			// compute box center and extents
			this.getCenter( center );
			extents.subVectors( this.max, center );

			// translate triangle to aabb origin
			v0.subVectors( triangle.a, center );
			v1.subVectors( triangle.b, center );
			v2.subVectors( triangle.c, center );

			// compute edge vectors for triangle
			f0.subVectors( v1, v0 );
			f1.subVectors( v2, v1 );
			f2.subVectors( v0, v2 );

			// test against axes that are given by cross product combinations of the edges of the triangle and the edges of the aabb
			// make an axis testing of each of the 3 sides of the aabb against each of the 3 sides of the triangle = 9 axis of separation
			// axis_ij = u_i x f_j (u0, u1, u2 = face normals of aabb = x,y,z axes vectors since aabb is axis aligned)
			var axes = [
				0, - f0.z, f0.y, 0, - f1.z, f1.y, 0, - f2.z, f2.y,
				f0.z, 0, - f0.x, f1.z, 0, - f1.x, f2.z, 0, - f2.x,
				- f0.y, f0.x, 0, - f1.y, f1.x, 0, - f2.y, f2.x, 0
			];
			if ( ! satForAxes( axes ) ) {

				return false;

			}

			// test 3 face normals from the aabb
			axes = [ 1, 0, 0, 0, 1, 0, 0, 0, 1 ];
			if ( ! satForAxes( axes ) ) {

				return false;

			}

			// finally testing the face normal of the triangle
			// use already existing triangle edge vectors here
			triangleNormal.crossVectors( f0, f1 );
			axes = [ triangleNormal.x, triangleNormal.y, triangleNormal.z ];
			return satForAxes( axes );

		};

	} )(),

	clampPoint: function ( point, optionalTarget ) {

		var result = optionalTarget || new Vector3();
		return result.copy( point ).clamp( this.min, this.max );

	},

	distanceToPoint: function () {

		var v1 = new Vector3();

		return function distanceToPoint( point ) {

			var clampedPoint = v1.copy( point ).clamp( this.min, this.max );
			return clampedPoint.sub( point ).length();

		};

	}(),

	getBoundingSphere: function () {

		var v1 = new Vector3();

		return function getBoundingSphere( optionalTarget ) {

			var result = optionalTarget || new Sphere();

			this.getCenter( result.center );

			result.radius = this.getSize( v1 ).length() * 0.5;

			return result;

		};

	}(),

	intersect: function ( box ) {

		this.min.max( box.min );
		this.max.min( box.max );

		// ensure that if there is no overlap, the result is fully empty, not slightly empty with non-inf/+inf values that will cause subsequence intersects to erroneously return valid values.
		if ( this.isEmpty() ) this.makeEmpty();

		return this;

	},

	union: function ( box ) {

		this.min.min( box.min );
		this.max.max( box.max );

		return this;

	},

	applyMatrix4: function () {

		var points = [
			new Vector3(),
			new Vector3(),
			new Vector3(),
			new Vector3(),
			new Vector3(),
			new Vector3(),
			new Vector3(),
			new Vector3()
		];

		return function applyMatrix4( matrix ) {

			// transform of empty box is an empty box.
			if ( this.isEmpty() ) return this;

			// NOTE: I am using a binary pattern to specify all 2^3 combinations below
			points[ 0 ].set( this.min.x, this.min.y, this.min.z ).applyMatrix4( matrix ); // 000
			points[ 1 ].set( this.min.x, this.min.y, this.max.z ).applyMatrix4( matrix ); // 001
			points[ 2 ].set( this.min.x, this.max.y, this.min.z ).applyMatrix4( matrix ); // 010
			points[ 3 ].set( this.min.x, this.max.y, this.max.z ).applyMatrix4( matrix ); // 011
			points[ 4 ].set( this.max.x, this.min.y, this.min.z ).applyMatrix4( matrix ); // 100
			points[ 5 ].set( this.max.x, this.min.y, this.max.z ).applyMatrix4( matrix ); // 101
			points[ 6 ].set( this.max.x, this.max.y, this.min.z ).applyMatrix4( matrix ); // 110
			points[ 7 ].set( this.max.x, this.max.y, this.max.z ).applyMatrix4( matrix );	// 111

			this.setFromPoints( points );

			return this;

		};

	}(),

	translate: function ( offset ) {

		this.min.add( offset );
		this.max.add( offset );

		return this;

	},

	equals: function ( box ) {

		return box.min.equals( this.min ) && box.max.equals( this.max );

	}

} );


export { Box3 };