three
Version:
JavaScript 3D library
175 lines (95 loc) • 3.22 kB
JavaScript
/**
* @author bhouston / http://clara.io
* @author mrdoob / http://mrdoob.com/
*/
THREE.Sphere = function ( center, radius ) {
this.center = ( center !== undefined ) ? center : new THREE.Vector3();
this.radius = ( radius !== undefined ) ? radius : 0;
};
THREE.Sphere.prototype = {
constructor: THREE.Sphere,
set: function ( center, radius ) {
this.center.copy( center );
this.radius = radius;
return this;
},
setFromPoints: function () {
var box = new THREE.Box3();
return function ( points, optionalCenter ) {
var center = this.center;
if ( optionalCenter !== undefined ) {
center.copy( optionalCenter );
} else {
box.setFromPoints( points ).center( center );
}
var maxRadiusSq = 0;
for ( var i = 0, il = points.length; i < il; i ++ ) {
maxRadiusSq = Math.max( maxRadiusSq, center.distanceToSquared( points[ i ] ) );
}
this.radius = Math.sqrt( maxRadiusSq );
return this;
};
}(),
clone: function () {
return new this.constructor().copy( this );
},
copy: function ( sphere ) {
this.center.copy( sphere.center );
this.radius = sphere.radius;
return this;
},
empty: function () {
return ( this.radius <= 0 );
},
containsPoint: function ( point ) {
return ( point.distanceToSquared( this.center ) <= ( this.radius * this.radius ) );
},
distanceToPoint: function ( point ) {
return ( point.distanceTo( this.center ) - this.radius );
},
intersectsSphere: function ( sphere ) {
var radiusSum = this.radius + sphere.radius;
return sphere.center.distanceToSquared( this.center ) <= ( radiusSum * radiusSum );
},
intersectsBox: function ( box ) {
return box.intersectsSphere( this );
},
intersectsPlane: function ( plane ) {
// We use the following equation to compute the signed distance from
// the center of the sphere to the plane.
//
// distance = q * n - d
//
// If this distance is greater than the radius of the sphere,
// then there is no intersection.
return Math.abs( this.center.dot( plane.normal ) - plane.constant ) <= this.radius;
},
clampPoint: function ( point, optionalTarget ) {
var deltaLengthSq = this.center.distanceToSquared( point );
var result = optionalTarget || new THREE.Vector3();
result.copy( point );
if ( deltaLengthSq > ( this.radius * this.radius ) ) {
result.sub( this.center ).normalize();
result.multiplyScalar( this.radius ).add( this.center );
}
return result;
},
getBoundingBox: function ( optionalTarget ) {
var box = optionalTarget || new THREE.Box3();
box.set( this.center, this.center );
box.expandByScalar( this.radius );
return box;
},
applyMatrix4: function ( matrix ) {
this.center.applyMatrix4( matrix );
this.radius = this.radius * matrix.getMaxScaleOnAxis();
return this;
},
translate: function ( offset ) {
this.center.add( offset );
return this;
},
equals: function ( sphere ) {
return sphere.center.equals( this.center ) && ( sphere.radius === this.radius );
}
};