three.js 源码注释（十二）Math/Box3.js

商域无疆 (http://blog.csdn.net/omni360/)

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转载请保留此句：商域无疆 -  本博客专注于 敏捷开发及移动和物联设备研究：数据可视化、GOLANG、Html5、WEBGL、THREE.JS，否则，出自本博客的文章拒绝转载或再转载，谢谢合作。

俺也是刚开始学,好多地儿肯定不对还请见谅.

以下代码是THREE.JS 源码文件中Math/Box3.js文件的注释.

更多更新在 : https://github.com/omni360/three.js.sourcecode/blob/master/Three.js

// File:src/math/Box3.js/** * @author bhouston / http://exocortex.com * @author WestLangley / http://github.com/WestLangley *//*///Box3对象的构造函数.用来在三维空间内创建一个立方体边界对象.Box3对象的功能函数采用///定义构造的函数原型对象来实现./// NOTE:如果没有参数min,max将立方体边界初始化为Infinity,无穷大//////用法: var min = new Vector3(0,0,0),max = new Vector3(1,1,1); var box = new Box3(min,max);///通过两个Vector3(三维向量)min,max创建一个立方体边界对象.*////<summary>Box3</summary>///<param name ="min" type="Vector3">边界的最小坐标值</param>///<param name ="max" type="Vector3">边界的最大坐标值</param>THREE.Box3 = function ( min, max ) {this.min = ( min !== undefined ) ? min : new THREE.Vector3( Infinity, Infinity, Infinity );//Infinity 正无穷大 this.max = ( max !== undefined ) ? max : new THREE.Vector3( - Infinity, - Infinity, - Infinity );//- Infinity负无穷大};/********************************************下面是Box3对象提供的功能函数.****************************************/THREE.Box3.prototype = {constructor: THREE.Box3,//构造器,返回对创建此对象的Box3函数的引用/*///set方法用来从新设置立方体边界的起始点,结束点,min,max坐标值.并返回新的坐标值的立方体边界.*////<summary>set</summary>///<param name ="min" type="Vector3">边界的最小坐标值</param>///<param name ="max" type="Vector3">边界的最大坐标值</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>set: function ( min, max ) {this.min.copy( min );this.max.copy( max );return this;//返回新坐标值的立方体边界},/*///setFromPoints方法通过Vector3对象组成的points数组重新设置立方体边界的最小值,最大值,min,max坐标值.并返回新的坐标值的立方体边界.*////<summary>setFromPoints</summary>///<param name ="points" type="Vector3Array">Vector3对象组成的points数组</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>setFromPoints: function ( points ) {this.makeEmpty();for ( var i = 0, il = points.length; i < il; i ++ ) {this.expandByPoint( points[ i ] )//调用.expandByPoint()方法,获得points数组中的最小,最大坐标,然后扩展边界.}return this;//返回新坐标值的立方体边界},/*///setFromCenterAndSize方法通过中心点,边界尺寸方式重新设置立方体边界的最小值,最大值,min,max坐标值.并返回新的坐标值的立方体边界.*////<summary>setFromCenterAndSize</summary>///<param name ="center" type="Vector3">Vector3对象,中心点坐标</param>///<param name ="size" type="Number">边界尺寸</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>setFromCenterAndSize: function () {var v1 = new THREE.Vector3();return function ( center, size ) {var halfSize = v1.copy( size ).multiplyScalar( 0.5 );this.min.copy( center ).sub( halfSize );this.max.copy( center ).add( halfSize );return this;//返回新坐标值的立方体边界};}(),/*///setFromObject方法通过获得参数object的端点重新设置立方体边界的最小值,最大值,min,max坐标值.并返回新的坐标值的立方体边界.*////<summary>setFromObject</summary>///<param name ="object" type="Object3D">Object3D对象</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>setFromObject: function () {// Computes the world-axis-aligned bounding box of an object (including its children),// accounting for both the object's, and childrens', world transforms//变换世界坐标系,通过获取Object3D对象(包括子对象)的端点设置立方体边界var v1 = new THREE.Vector3();return function ( object ) {var scope = this;object.updateMatrixWorld( true );//设置全局变换,object以及子对象都应用变换.//TODO: updateMatrixWorld()方法还没细看,this.makeEmpty();//调用Box3.makeEmpty()方法,将立方体边界设置成无穷大.object.traverse( function ( node ) {if ( node.geometry !== undefined && node.geometry.vertices !== undefined ) {var vertices = node.geometry.vertices;for ( var i = 0, il = vertices.length; i < il; i ++ ) {v1.copy( vertices[ i ] );v1.applyMatrix4( node.matrixWorld );scope.expandByPoint( v1 );//调用expandByPoint()方法重新设置立方体边界}}} );return this;//返回新坐标值的立方体边界};}(),/*///copy方法用来复制立方体边界的最小值,最大值,min,max坐标值.并返回新的坐标值的立方体边界.*////<summary>copy</summary>///<param name ="box" type="Box3">立方体边界</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>copy: function ( box ) {this.min.copy( box.min );this.max.copy( box.max );return this;//返回新坐标值的立方体边界},/*///makeEmpty方法用来将立方体边界初始化为Infinity,无穷大*////<summary>makeEmpty</summary>///<returns type="Box3">返回新坐标值的立方体边界</returns>makeEmpty: function () {this.min.x = this.min.y = this.min.z = Infinity;//将立方体边界初始化为Infinity,无穷大this.max.x = this.max.y = this.max.z = - Infinity;//将立方体边界初始化为Infinity,无穷大return this;//返回新坐标值的立方体边界},/*///empty方法用来判断立方体边界的最大值的x,y是否小于最小值的x,y./// NOTE:如果此框包括零点在其边界返回true。/// NOTE:一个box有最大,最小边界,最大最小边界分别用一个点表示,这个点被两个边界共享./// TODO:empty方法没有弄明白.什么时候用.*////<summary>empty</summary>///<returns type="Boolean">返回true 或者 false</returns>empty: function () {// this is a more robust check for empty than ( volume <= 0 ) because volume can get positive with two negative axesreturn ( this.max.x < this.min.x ) || ( this.max.y < this.min.y ) || ( this.max.z < this.min.z );//返回true 或者 false},/*///center方法用来返回立方体边界的中点*////<summary>center</summary>///<param name ="optionalTarget" type="Vector3">可选参数,接收返回结果,边界的中点</param>///<returns type="Vector3">返回立方体边界的中点</returns>center: function ( optionalTarget ) {var result = optionalTarget || new THREE.Vector3();return result.addVectors( this.min, this.max ).multiplyScalar( 0.5 );//返回立方体边界的中点},/*///size方法用来返回立方体边界尺寸的向量*////<summary>size</summary>///<param name ="optionalTarget" type="Vector3">可选参数,接收返回结果,边界尺寸的向量</param>///<returns type="Vector3">返回立方体边界尺寸的向量</returns>size: function ( optionalTarget ) {var result = optionalTarget || new THREE.Vector3();return result.subVectors( this.max, this.min );//返回立方体边界尺寸的向量},/*///expandByPoint方法通过Vector3对象(point参数)扩展立方体边界的最小值,最大值,min,max坐标值.并返回新的坐标值的立方体边界./// NOTE:expandByPoint方法与expandByVector方法都传递一个Vector3对象,expandByPoint方法将当前边界的最大值,最小值的x,y坐标对比,获得新的边界,但是expandByVector方法将立方体边界的最大值加上参数vector,最小值减去参数vector,*////<summary>expandByPoint</summary>///<param name ="points" type="Vector3">Vector3对象</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>expandByPoint: function ( point ) {this.min.min( point );this.max.max( point );return this;//返回新坐标值的立方体边界},/*///expandByVector方法通过Vector3对象(vector参数)扩展立方体边界的最小值,最大值,min,max坐标值.并返回新的坐标值的立方体边界./// NOTE:expandByVector方法与expandByScalar方法不同的是expandByVector()接收一个向量,expandByScalar()方法接收一个标量.*////<summary>expandByVector</summary>///<param name ="scalar" type="Number">数值对象</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>expandByVector: function ( vector ) {this.min.sub( vector );this.max.add( vector );return this;//返回新坐标值的立方体边界},/*///expandByScalar方法通过Vector3对象(Scalar参数)扩展立方体边界的最小值,最大值,min,max坐标值.并返回新的坐标值的立方体边界./// NOTE:expandByScalar方法与expandByVector方法不同的是expandByVector()接收一个向量,expandByScalar()方法接收一个标量.*////<summary>expandByScalar</summary>///<param name ="scalar" type="Number">数值对象</param>///<returns type="Box3">返回新坐标值的立方体边界</returns>expandByScalar: function ( scalar ) {this.min.addScalar( - scalar );this.max.addScalar( scalar );return this;},/*///containsPoint方法用来获得参数point(一个Vector3的三维点坐标)是否在当前立方体边界内.*////<summary>containsPoint</summary>///<param name ="point" type="Vector3">一个Vector3的三维点坐标</param>///<returns type="Boolean">返回true 或者 false</returns>containsPoint: function ( point ) {if ( 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 ) {return false;//不在边界内,返回false}return true;//在边界内,返回true},/*///containsBox方法用来获得参数box(一个Box3的立方体边界)是否在当前立方体边界内.*////<summary>containsBox</summary>///<param name ="box" type="Box3">一个Box3的立方体边界</param>///<returns type="Boolean">返回true 或者 false</returns>containsBox: function ( box ) {if ( ( 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 ) ) {return true;//在边界内,返回true}return false;//不在边界内,返回false},/*///getParameter方法用来获得参数point(一个Vector3的三维点坐标)在当前立方体边界的长高宽比.///示例: var point = new Vector3(3,2,3);/// var min= new Vector3(1,1,1),max = new Vector3(5,5,5);/// var box = new Box3(min,max); //一个4x4的边界/// var ot = new Vector3();/// box.getParameter(point,ot);/// ot= 3/4,1/2,3/4*////<summary>containsBox</summary>///<param name ="box" type="Box3">一个Box3的立方体边界</param>///<param name ="optionalTarget" type="Vector3">可选参数,接收返回结果,含长高宽比的三维向量</param>///<returns type="Vector3">返回包含高宽比的三维向量.</returns>getParameter: function ( point, optionalTarget ) {// This can potentially have a divide by zero if the box// has a size dimension of 0.// NOTE:这里可能会出现除数0.var result = optionalTarget || new THREE.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 ));//返回包含长高宽比的三维向量},/*///isIntersectionBox方法用来获得参数box(一个Box3的立方体边界)是否与当前立方体边界相交.*////<summary>isIntersectionBox</summary>///<param name ="box" type="Box3">一个Box3的立方体边界</param>///<returns type="Boolean">返回true 或者 false</returns>isIntersectionBox: function ( box ) {// using 6 splitting planes to rule out intersections.if ( 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 ) {return false;//如果不相交,返回false}return true;//如果相交,返回true.},/*///clampPoint方法用来限制参数point在立方体边界内.如果point小于min,返回min,如果大于max返回max,否则返回point*////<summary>clampPoint</summary>///<param name ="point" type="Vector3">一个Vector3的三维点坐标</param>///<param name ="optionalTarget" type="Vector3">可选参数,接收返回结果,返回剪裁过的边界点</param>///<returns type="Vector3">返回剪裁过的边界点.</returns>clampPoint: function ( point, optionalTarget ) {var result = optionalTarget || new THREE.Vector3();return result.copy( point ).clamp( this.min, this.max );//返回剪裁过的边界点},/*///distanceToPoint方法用来获得边界内一点到最小边界,最大边界的长度(box的12条边的长度).*////<summary>distanceToPoint</summary>///<param name ="point" type="Vector3">一个边界内的Vector3的三维点坐标</param>///<returns type="Number">返回边界内一点到最小边界,最大边界的长度(box的12条边的长度).</returns>distanceToPoint: function () {var v1 = new THREE.Vector3();return function ( point ) {var clampedPoint = v1.copy( point ).clamp( this.min, this.max );return clampedPoint.sub( point ).length();//返回边界内一点到最小边界,最大边界的长度(box的12条边的长度).};}(),/*///getBoundingSphere方法返回当前立方体边界的球形边界(这里应该内切于立方体边界的一个球体)*////<summary>getBoundingSphere</summary>///<param name ="optionalTarget" type="THREE.Sphere()">可选参数,THREE.Sphere()球体对象,用来接收返回值</param>///<returns type="THREE.Sphere()">返回当前立方体边界的球形边界(这里应该内切于立方体边界的一个球体)</returns>getBoundingSphere: function () {var v1 = new THREE.Vector3();return function ( optionalTarget ) {var result = optionalTarget || new THREE.Sphere();result.center = this.center();//将球体边界中心设置为当前立方体中心result.radius = this.size( v1 ).length() * 0.5;//设置球体边界的半径return result;//返回当前立方体边界的球形边界(这里应该内切于立方体边界的一个球体)};}(),/*///intersect方法用来通过收缩当前立方体边界,求当前立方体边界和参数box的交集.*////<summary>intersect</summary>///<param name ="box" type="Box3">一个Box3的立方体边界</param>///<returns type="Boolean">返回当前立方体边界和参数box的交集</returns>intersect: function ( box ) {this.min.max( box.min );this.max.min( box.max );return this;//返回当前立方体边界和参数box的交集},/*///intersect方法用来通过扩展当前立方体边界,将参数box包围进当前的立方体边界内.就是取两个边界的并集*////<summary>intersect</summary>///<param name ="box" type="Box3">一个Box3的立方体边界</param>///<returns type="Boolean">返回两个边界的并集</returns>union: function ( box ) {this.min.min( box.min );this.max.max( box.max );return this;//返回两个边界的并集},/*///applyMatrix4方法通过传递matrix(旋转,缩放,移动等变换矩阵)对当前立方体对象的8个角点,应用变换.*////<summary>applyMatrix4</summary>///<param name ="matrix" type="Matrix4">(旋转,缩放,移动等变换矩阵</param>///<returns type="Boolean">返回变换后的立方体边界.</returns>applyMatrix4: function () {var points = [new THREE.Vector3(),new THREE.Vector3(),new THREE.Vector3(),new THREE.Vector3(),new THREE.Vector3(),new THREE.Vector3(),new THREE.Vector3(),new THREE.Vector3()];return function ( matrix ) {// NOTE: I am using a binary pattern to specify all 2^3 combinations below// NOTE: 作者通过3个二进制位表示8个角点.points[ 0 ].set( this.min.x, this.min.y, this.min.z ).applyMatrix4( matrix ); // 000points[ 1 ].set( this.min.x, this.min.y, this.max.z ).applyMatrix4( matrix ); // 001points[ 2 ].set( this.min.x, this.max.y, this.min.z ).applyMatrix4( matrix ); // 010points[ 3 ].set( this.min.x, this.max.y, this.max.z ).applyMatrix4( matrix ); // 011points[ 4 ].set( this.max.x, this.min.y, this.min.z ).applyMatrix4( matrix ); // 100points[ 5 ].set( this.max.x, this.min.y, this.max.z ).applyMatrix4( matrix ); // 101points[ 6 ].set( this.max.x, this.max.y, this.min.z ).applyMatrix4( matrix ); // 110points[ 7 ].set( this.max.x, this.max.y, this.max.z ).applyMatrix4( matrix );  // 111this.makeEmpty();this.setFromPoints( points );//调用setFromPoints()方法,重新设置立方体边界.return this;//返回变换后的立方体边界.};}(),/*///translate方法用来通过参数offset,移动当前立方体边界的位置.*////<summary>translate</summary>///<param name ="offset" type="Vector3">偏移量</param>///<returns type="Boolean">返回新坐标值的立方体边界</returns>translate: function ( offset ) {this.min.add( offset );this.max.add( offset );return this;//返回新坐标值的立方体边界},/*///equals方法用来获得参数box(一个Box3的立方体边界)是否与当前立方体边界完全相等.*////<summary>equals</summary>///<param name ="box" type="Box3">一个Box3的立方体边界</param>///<returns type="Boolean">返回true 或者 false</returns>equals: function ( box ) {return box.min.equals( this.min ) && box.max.equals( this.max );//返回true 或者 false},/*clone方法///clone方法克隆一个立方体边界对象.*////<summary>clone</summary>///<returns type="Box3">返回立方体边界对象</returns>clone: function () {return new THREE.Box3().copy( this );//返回立方体边界对象}};

商域无疆 (http://blog.csdn.net/omni360/)

本文遵循“署名-非商业用途-保持一致”创作公用协议

转载请保留此句：商域无疆 -  本博客专注于 敏捷开发及移动和物联设备研究：数据可视化、GOLANG、Html5、WEBGL、THREE.JS，否则，出自本博客的文章拒绝转载或再转载，谢谢合作。

以下代码是THREE.JS 源码文件中Math/Box3.js文件的注释.

更多更新在 : https://github.com/omni360/three.js.sourcecode/blob/master/Three.js