Accueil / npm / three@0.186.1 / src / math / Box2.js
Box2.js
import { Vector2 } from './Vector2.js';
const _vector = /*@__PURE__*/ new Vector2();
/**
* Represents an axis-aligned bounding box (AABB) in 2D space.
*/
class Box2 {
/**
* Constructs a new bounding box.
*
* @param {Vector2} [min=(Infinity,Infinity)] - A vector representing the lower boundary of the box.
* @param {Vector2} [max=(-Infinity,-Infinity)] - A vector representing the upper boundary of the box.
*/
constructor( min = new Vector2( + Infinity, + Infinity ), max = new Vector2( - Infinity, - Infinity ) ) {
/**
* This flag can be used for type testing.
*
* @type {boolean}
* @readonly
* @default true
*/
this.isBox2 = true;
/**
* The lower boundary of the box.
*
* @type {Vector2}
*/
this.min = min;
/**
* The upper boundary of the box.
*
* @type {Vector2}
*/
this.max = max;
}
/**
* Sets the lower and upper boundaries of this box.
* Please note that this method only copies the values from the given objects.
*
* @param {Vector2} min - The lower boundary of the box.
* @param {Vector2} max - The upper boundary of the box.
* @return {Box2} A reference to this bounding box.
*/
set( min, max ) {
this.min.copy( min );
this.max.copy( max );
return this;
}
/**
* Sets the upper and lower bounds of this box so it encloses the position data
* in the given array.
*
* @param {Array<Vector2>} points - An array holding 2D position data as instances of {@link Vector2}.
* @return {Box2} A reference to this bounding box.
*/
setFromPoints( points ) {
this.makeEmpty();
for ( let i = 0, il = points.length; i < il; i ++ ) {
this.expandByPoint( points[ i ] );
}
return this;
}
/**
* Centers this box on the given center vector and sets this box's width, height and
* depth to the given size values.
*
* @param {Vector2} center - The center of the box.
* @param {Vector2} size - The x and y dimensions of the box.
* @return {Box2} A reference to this bounding box.
*/
setFromCenterAndSize( center, size ) {
const halfSize = _vector.copy( size ).multiplyScalar( 0.5 );
this.min.copy( center ).sub( halfSize );
this.max.copy( center ).add( halfSize );
return this;
}
/**
* Returns a new box with copied values from this instance.
*
* @return {Box2} A clone of this instance.
*/
clone() {
return new this.constructor().copy( this );
}
/**
* Copies the values of the given box to this instance.
*
* @param {Box2} box - The box to copy.
* @return {Box2} A reference to this bounding box.
*/
copy( box ) {
this.min.copy( box.min );
this.max.copy( box.max );
return this;
}
/**
* Makes this box empty which means in encloses a zero space in 2D.
*
* @return {Box2} A reference to this bounding box.
*/
makeEmpty() {
this.min.x = this.min.y = + Infinity;
this.max.x = this.max.y = - Infinity;
return this;
}
/**
* Returns true if this box includes zero points within its bounds.
* Note that a box with equal lower and upper bounds still includes one
* point, the one both bounds share.
*
* @return {boolean} Whether this box is empty or not.
*/
isEmpty() {
// 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 );
}
/**
* Returns the center point of this box.
*
* @param {Vector2} target - The target vector that is used to store the method's result.
* @return {Vector2} The center point.
*/
getCenter( target ) {
return this.isEmpty() ? target.set( 0, 0 ) : target.addVectors( this.min, this.max ).multiplyScalar( 0.5 );
}
/**
* Returns the dimensions of this box.
*
* @param {Vector2} target - The target vector that is used to store the method's result.
* @return {Vector2} The size.
*/
getSize( target ) {
return this.isEmpty() ? target.set( 0, 0 ) : target.subVectors( this.max, this.min );
}
/**
* Expands the boundaries of this box to include the given point.
*
* @param {Vector2} point - The point that should be included by the bounding box.
* @return {Box2} A reference to this bounding box.
*/
expandByPoint( point ) {
this.min.min( point );
this.max.max( point );
return this;
}
/**
* Expands this box equilaterally by the given vector. The width of this
* box will be expanded by the x component of the vector in both
* directions. The height of this box will be expanded by the y component of
* the vector in both directions.
*
* @param {Vector2} vector - The vector that should expand the bounding box.
* @return {Box2} A reference to this bounding box.
*/
expandByVector( vector ) {
this.min.sub( vector );
this.max.add( vector );
return this;
}
/**
* Expands each dimension of the box by the given scalar. If negative, the
* dimensions of the box will be contracted.
*
* @param {number} scalar - The scalar value that should expand the bounding box.
* @return {Box2} A reference to this bounding box.
*/
expandByScalar( scalar ) {
this.min.addScalar( - scalar );
this.max.addScalar( scalar );
return this;
}
/**
* Returns `true` if the given point lies within or on the boundaries of this box.
*
* @param {Vector2} point - The point to test.
* @return {boolean} Whether the bounding box contains the given point or not.
*/
containsPoint( point ) {
return point.x >= this.min.x && point.x <= this.max.x &&
point.y >= this.min.y && point.y <= this.max.y;
}
/**
* Returns `true` if this bounding box includes the entirety of the given bounding box.
* If this box and the given one are identical, this function also returns `true`.
*
* @param {Box2} box - The bounding box to test.
* @return {boolean} Whether the bounding box contains the given bounding box or not.
*/
containsBox( 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;
}
/**
* Returns a point as a proportion of this box's width and height.
*
* @param {Vector2} point - A point in 2D space.
* @param {Vector2} target - The target vector that is used to store the method's result.
* @return {Vector2} A point as a proportion of this box's width and height.
*/
getParameter( point, target ) {
// This can potentially have a divide by zero if the box
// has a size dimension of 0.
return target.set(
( point.x - this.min.x ) / ( this.max.x - this.min.x ),
( point.y - this.min.y ) / ( this.max.y - this.min.y )
);
}
/**
* Returns `true` if the given bounding box intersects with this bounding box.
*
* @param {Box2} box - The bounding box to test.
* @return {boolean} Whether the given bounding box intersects with this bounding box.
*/
intersectsBox( box ) {
// using 4 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;
}
/**
* Clamps the given point within the bounds of this box.
*
* @param {Vector2} point - The point to clamp.
* @param {Vector2} target - The target vector that is used to store the method's result.
* @return {Vector2} The clamped point.
*/
clampPoint( point, target ) {
return target.copy( point ).clamp( this.min, this.max );
}
/**
* Returns the euclidean distance from any edge of this box to the specified point. If
* the given point lies inside of this box, the distance will be `0`.
*
* @param {Vector2} point - The point to compute the distance to.
* @return {number} The euclidean distance.
*/
distanceToPoint( point ) {
return this.clampPoint( point, _vector ).distanceTo( point );
}
/**
* Computes the intersection of this bounding box and the given one, setting the upper
* bound of this box to the lesser of the two boxes' upper bounds and the
* lower bound of this box to the greater of the two boxes' lower bounds. If
* there's no overlap, makes this box empty.
*
* @param {Box2} box - The bounding box to intersect with.
* @return {Box2} A reference to this bounding box.
*/
intersect( box ) {
this.min.max( box.min );
this.max.min( box.max );
if ( this.isEmpty() ) this.makeEmpty();
return this;
}
/**
* Computes the union of this box and another and the given one, setting the upper
* bound of this box to the greater of the two boxes' upper bounds and the
* lower bound of this box to the lesser of the two boxes' lower bounds.
*
* @param {Box2} box - The bounding box that will be unioned with this instance.
* @return {Box2} A reference to this bounding box.
*/
union( box ) {
this.min.min( box.min );
this.max.max( box.max );
return this;
}
/**
* Adds the given offset to both the upper and lower bounds of this bounding box,
* effectively moving it in 2D space.
*
* @param {Vector2} offset - The offset that should be used to translate the bounding box.
* @return {Box2} A reference to this bounding box.
*/
translate( offset ) {
this.min.add( offset );
this.max.add( offset );
return this;
}
/**
* Returns `true` if this bounding box is equal with the given one.
*
* @param {Box2} box - The box to test for equality.
* @return {boolean} Whether this bounding box is equal with the given one.
*/
equals( box ) {
return box.min.equals( this.min ) && box.max.equals( this.max );
}
}
export { Box2 };