three.js 源码注释(十二)Math/Box3.js
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。
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 axes return ( 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 ); // 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.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
郑重声明:本站内容如果来自互联网及其他传播媒体,其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享,并不代表本站赞同其观点和对其真实性负责,也不构成任何其他建议。