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three.js 源代码凝视(九)Math/Matrix4.js

时间:2017-05-14 18:06:54      阅读:381      评论:0      收藏:0      [点我收藏+]

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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。


今天把math库中最大的对象Matrix4凝视完了,发现之前好多的凝视理解的不太正确,还有好多的凝视由于马虎,好多小错误.能改的都在github上更新了,只是大概意思,临时我觉得是正确的.哈哈哈:)

下面代码是THREE.JS 源代码文件里Math/Matrix4.js文件的凝视.

很多其它更新在 : https://github.com/omni360/three.js.sourcecode/blob/master/Three.js


// File:src/math/Matrix4.js

/**
 * @author mrdoob / http://mrdoob.com/
 * @author supereggbert / http://www.paulbrunt.co.uk/
 * @author philogb / http://blog.thejit.org/
 * @author jordi_ros / http://plattsoft.com
 * @author D1plo1d / http://github.com/D1plo1d
 * @author alteredq / http://alteredqualia.com/
 * @author mikael emtinger / http://gomo.se/
 * @author timknip / http://www.floorplanner.com/
 * @author bhouston / http://exocortex.com
 * @author WestLangley / http://github.com/WestLangley
 */
///Matrix4对象的构造函数.用来创建一个4x4矩阵.Matrix4对象的功能函数採用
///定义构造的函数原型对象来实现,实际就是一个数组.
///
///	使用方法: var m = new Matrix4(11, 12, 13, 14, 21, 22, 23, 24, 31, 32, 33, 34, 41, 42, 43, 44)
///	创建一个4x4的矩阵,事实上就是一个长度为9的数组,将參数(11, 12, 13, 21, 22, 23, 31, 32, 33, 41, 42, 43, 44)传递给数组用来初始化.
/// 一个变换矩阵能够运行随意的线形3D变换(比如,平移。旋转,缩放。切边等等)并且透视变换使用齐次坐标。

/// 脚本中非常少使用矩阵:最经常使用Vector3,Quaternion。并且Transform类的功能更简单。单纯的矩阵用于特殊情况,如设置非标准相机投影。

/// /// NOTE: 參数 n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, 41, 42, 43, 44 代表4x4矩阵中的元素的值,n11表示矩阵的第一行,第一列的元素值 /// ///<summary>Matrix4</summary> ///<param name ="n11" type="number">n11第 1 行,第 1 列的元素值</param> ///<param name ="n12" type="number">n12第 1 行,第 2 列的元素值</param> ///<param name ="n13" type="number">n13第 1 行,第 3 列的元素值</param> ///<param name ="n13" type="number">n13第 1 行,第 4 列的元素值</param> ///<param name ="n21" type="number">n21第 2 行,第 1 列的元素值</param> ///<param name ="n22" type="number">n22第 2 行,第 2 列的元素值</param> ///<param name ="n23" type="number">n23第 2 行,第 3 列的元素值</param> ///<param name ="n23" type="number">n23第 2 行,第 4 列的元素值</param> ///<param name ="n31" type="number">n31第 3 行,第 1 列的元素值</param> ///<param name ="n32" type="number">n32第 3 行,第 2 列的元素值</param> ///<param name ="n33" type="number">n33第 3 行,第 3 列的元素值</param> ///<param name ="n33" type="number">n33第 3 行,第 4 列的元素值</param> ///<param name ="n31" type="number">n31第 4 行,第 1 列的元素值</param> ///<param name ="n32" type="number">n32第 4 行,第 2 列的元素值</param> ///<param name ="n33" type="number">n33第 4 行,第 3 列的元素值</param> ///<param name ="n33" type="number">n33第 4 行,第 4 列的元素值</param> ///<returns type="Matrix4">返回新的4x4矩阵</returns> THREE.Matrix4 = function ( n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, n41, n42, n43, n44 ) { this.elements = new Float32Array( 16 ); // TODO: 假设n11未定义,Matrix4将被初始化为一个单位矩阵.假设n11定义了值,直接复制该值到矩阵中. // TODO: if n11 is undefined, then just set to identity, otherwise copy all other values into matrix // 我们不支持semi规范的Matrix4(4x4矩阵),semi规范非常奇怪?

??(英语实在只是关) // we should not support semi specification of Matrix4, it is just weird. var te = this.elements; te[ 0 ] = ( n11 !== undefined ) ?

n11 : 1; te[ 4 ] = n12 || 0; te[ 8 ] = n13 || 0; te[ 12 ] = n14 || 0; te[ 1 ] = n21 || 0; te[ 5 ] = ( n22 !== undefined ) ? n22 : 1; te[ 9 ] = n23 || 0; te[ 13 ] = n24 || 0; te[ 2 ] = n31 || 0; te[ 6 ] = n32 || 0; te[ 10 ] = ( n33 !== undefined ) ?

n33 : 1; te[ 14 ] = n34 || 0; te[ 3 ] = n41 || 0; te[ 7 ] = n42 || 0; te[ 11 ] = n43 || 0; te[ 15 ] = ( n44 !== undefined ) ? n44 : 1; //初始化Matrix4(4x4矩阵)对象. }; /**************************************** ****以下是Matrix4对象提供的功能函数. ****************************************/ THREE.Matrix4.prototype = { constructor: THREE.Matrix4, //构造器 /* ///set方法用来从新设置Matrix4(4x4矩阵)的元素值.并返回新的坐标值的Matrix4(4x4矩阵). /// TODO:改动set方法,兼容 n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, 41, 42, 43, 44 參数省略支持多态. */ ///<summary>set</summary> ///<param name ="n11" type="number">n11第 1 行,第 1 列的元素值</param> ///<param name ="n12" type="number">n12第 1 行,第 2 列的元素值</param> ///<param name ="n13" type="number">n13第 1 行,第 3 列的元素值</param> ///<param name ="n13" type="number">n13第 1 行,第 4 列的元素值</param> ///<param name ="n21" type="number">n21第 2 行,第 1 列的元素值</param> ///<param name ="n22" type="number">n22第 2 行,第 2 列的元素值</param> ///<param name ="n23" type="number">n23第 2 行,第 3 列的元素值</param> ///<param name ="n23" type="number">n23第 2 行,第 4 列的元素值</param> ///<param name ="n31" type="number">n31第 3 行,第 1 列的元素值</param> ///<param name ="n32" type="number">n32第 3 行,第 2 列的元素值</param> ///<param name ="n33" type="number">n33第 3 行,第 3 列的元素值</param> ///<param name ="n33" type="number">n33第 3 行,第 4 列的元素值</param> ///<param name ="n31" type="number">n31第 4 行,第 1 列的元素值</param> ///<param name ="n32" type="number">n32第 4 行,第 2 列的元素值</param> ///<param name ="n33" type="number">n33第 4 行,第 3 列的元素值</param> ///<param name ="n33" type="number">n33第 4 行,第 4 列的元素值</param> ///<returns type="Matrix4">返回新的4x4矩阵</returns> set: function ( n11, n12, n13, n14, n21, n22, n23, n24, n31, n32, n33, n34, n41, n42, n43, n44 ) { var te = this.elements; te[ 0 ] = n11; te[ 4 ] = n12; te[ 8 ] = n13; te[ 12 ] = n14; te[ 1 ] = n21; te[ 5 ] = n22; te[ 9 ] = n23; te[ 13 ] = n24; te[ 2 ] = n31; te[ 6 ] = n32; te[ 10 ] = n33; te[ 14 ] = n34; te[ 3 ] = n41; te[ 7 ] = n42; te[ 11 ] = n43; te[ 15 ] = n44; return this; //返回新的4x4矩阵 }, /* ///identity方法用来获得一个4x4矩阵的单位矩阵 /// /// NOTE:在矩阵的乘法中。有一种矩阵起着特殊的作用,如同数的乘法中的1,我们称这样的矩阵为单位矩阵 /// 它是个方阵,从左上角到右下角的对角线(称为主对角线)上的元素均为1以外全都为0。 /// 对于单位矩阵。有AE=EA=A */ ///<summary>identity</summary> ///<returns type="Matrix4(4x4矩阵)">返回4x4矩阵的一个单位矩阵</returns> identity: function () { this.set( 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 ); return this; //返回4x4矩阵的一个单位矩阵 }, /* ///copy方法用来复制4x4矩阵的元素值.并返回新的Matrix4(4x4矩阵). */ ///<summary>copy</summary> ///<param name ="m" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> copy: function ( m ) { this.elements.set( m.elements ); return this; //返回新的Matrix4(4x4矩阵) }, /* ///extractPosition方法用来复制參数m(4x4矩阵)的平移分量.并返回新的Matrix4(4x4矩阵). /// NOTE: extractPosition方法已经被重命名为.copyPosition() */ ///<summary>extractPosition</summary> ///<param name ="m" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> extractPosition: function ( m ) { console.warn( ‘THREEMatrix4: .extractPosition() has been renamed to .copyPosition().‘ ); return this.copyPosition( m ); //调用copyPosition()方法,返回新的Matrix4(4x4矩阵) }, /* ///copyPosition方法用来复制參数m(4x4矩阵)的平移分量.并返回新的Matrix4(4x4矩阵). */ ///<summary>copyPosition</summary> ///<param name ="m" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> copyPosition: function ( m ) { var te = this.elements; var me = m.elements; te[ 12 ] = me[ 12 ]; te[ 13 ] = me[ 13 ]; te[ 14 ] = me[ 14 ]; return this; //返回新的Matrix4(4x4矩阵) }, /* ///extractRotation方法用来提取參数m(4x4矩阵)的旋转分量.并返回新的Matrix4(4x4矩阵). */ ///<summary>extractRotation</summary> ///<param name ="m" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> extractRotation: function () { var v1 = new THREE.Vector3(); return function ( m ) { var te = this.elements; var me = m.elements; var scaleX = 1 / v1.set( me[ 0 ], me[ 1 ], me[ 2 ] ).length(); var scaleY = 1 / v1.set( me[ 4 ], me[ 5 ], me[ 6 ] ).length(); var scaleZ = 1 / v1.set( me[ 8 ], me[ 9 ], me[ 10 ] ).length(); te[ 0 ] = me[ 0 ] * scaleX; te[ 1 ] = me[ 1 ] * scaleX; te[ 2 ] = me[ 2 ] * scaleX; te[ 4 ] = me[ 4 ] * scaleY; te[ 5 ] = me[ 5 ] * scaleY; te[ 6 ] = me[ 6 ] * scaleY; te[ 8 ] = me[ 8 ] * scaleZ; te[ 9 ] = me[ 9 ] * scaleZ; te[ 10 ] = me[ 10 ] * scaleZ; return this; //返回新的Matrix4(4x4矩阵) }; }(), /* ///applyEuler方法通过欧拉旋转(參数euler)对Matrix4(4x4矩阵)应用旋转变换. */ ///<summary>applyEuler</summary> ///<param name ="euler" type="THREE.Euler">THREE.Euler对象,欧拉对象</param> ///<returns type="Matrix4">返回变换后的Matrix4(4x4矩阵)</returns> makeRotationFromEuler: function ( euler ) { if ( euler instanceof THREE.Euler === false ) { console.error( ‘THREE.Matrix: .makeRotationFromEuler() now expects a Euler rotation rather than a Vector3 and order.‘ ); } var te = this.elements; var x = euler.x, y = euler.y, z = euler.z; var a = Math.cos( x ), b = Math.sin( x ); var c = Math.cos( y ), d = Math.sin( y ); var e = Math.cos( z ), f = Math.sin( z ); if ( euler.order === ‘XYZ‘ ) { var ae = a * e, af = a * f, be = b * e, bf = b * f; te[ 0 ] = c * e; te[ 4 ] = - c * f; te[ 8 ] = d; te[ 1 ] = af + be * d; te[ 5 ] = ae - bf * d; te[ 9 ] = - b * c; te[ 2 ] = bf - ae * d; te[ 6 ] = be + af * d; te[ 10 ] = a * c; } else if ( euler.order === ‘YXZ‘ ) { var ce = c * e, cf = c * f, de = d * e, df = d * f; te[ 0 ] = ce + df * b; te[ 4 ] = de * b - cf; te[ 8 ] = a * d; te[ 1 ] = a * f; te[ 5 ] = a * e; te[ 9 ] = - b; te[ 2 ] = cf * b - de; te[ 6 ] = df + ce * b; te[ 10 ] = a * c; } else if ( euler.order === ‘ZXY‘ ) { var ce = c * e, cf = c * f, de = d * e, df = d * f; te[ 0 ] = ce - df * b; te[ 4 ] = - a * f; te[ 8 ] = de + cf * b; te[ 1 ] = cf + de * b; te[ 5 ] = a * e; te[ 9 ] = df - ce * b; te[ 2 ] = - a * d; te[ 6 ] = b; te[ 10 ] = a * c; } else if ( euler.order === ‘ZYX‘ ) { var ae = a * e, af = a * f, be = b * e, bf = b * f; te[ 0 ] = c * e; te[ 4 ] = be * d - af; te[ 8 ] = ae * d + bf; te[ 1 ] = c * f; te[ 5 ] = bf * d + ae; te[ 9 ] = af * d - be; te[ 2 ] = - d; te[ 6 ] = b * c; te[ 10 ] = a * c; } else if ( euler.order === ‘YZX‘ ) { var ac = a * c, ad = a * d, bc = b * c, bd = b * d; te[ 0 ] = c * e; te[ 4 ] = bd - ac * f; te[ 8 ] = bc * f + ad; te[ 1 ] = f; te[ 5 ] = a * e; te[ 9 ] = - b * e; te[ 2 ] = - d * e; te[ 6 ] = ad * f + bc; te[ 10 ] = ac - bd * f; } else if ( euler.order === ‘XZY‘ ) { var ac = a * c, ad = a * d, bc = b * c, bd = b * d; te[ 0 ] = c * e; te[ 4 ] = - f; te[ 8 ] = d * e; te[ 1 ] = ac * f + bd; te[ 5 ] = a * e; te[ 9 ] = ad * f - bc; te[ 2 ] = bc * f - ad; te[ 6 ] = b * e; te[ 10 ] = bd * f + ac; } //最后一列 // last column te[ 3 ] = 0; te[ 7 ] = 0; te[ 11 ] = 0; //最以下的一行 // bottom row te[ 12 ] = 0; te[ 13 ] = 0; te[ 14 ] = 0; te[ 15 ] = 1; return this; //返回变换后的Matrix4(4x4矩阵) }, /* ///setRotationFromQuaternion方法通过四元数对Matrix4(4x4矩阵)应用旋转变换. /// NOTE: setRotationFromQuaternion()方法已经被重命名为makeRotationFromQuaternion(),这里保留是为了向下兼容. */ ///<summary>setRotationFromQuaternion</summary> ///<param name ="q" type="Quaternion">四元数</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> setRotationFromQuaternion: function ( q ) { console.warn( ‘THREE.Matrix4: .setRotationFromQuaternion() has been renamed to .makeRotationFromQuaternion().‘ ); return this.makeRotationFromQuaternion( q ); //调用makeRotationFromQuaternion()方法,应用旋转变换,并返回新的Matrix4(4x4矩阵)对象. }, /* ///makeRotationFromQuaternion方法通过四元数对Matrix4(4x4矩阵)应用旋转变换. */ ///<summary>setRotationFromQuaternion</summary> ///<param name ="q" type="Quaternion">四元数</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> makeRotationFromQuaternion: function ( q ) { var te = this.elements; var x = q.x, y = q.y, z = q.z, w = q.w; var x2 = x + x, y2 = y + y, z2 = z + z; var xx = x * x2, xy = x * y2, xz = x * z2; var yy = y * y2, yz = y * z2, zz = z * z2; var wx = w * x2, wy = w * y2, wz = w * z2; te[ 0 ] = 1 - ( yy + zz ); te[ 4 ] = xy - wz; te[ 8 ] = xz + wy; te[ 1 ] = xy + wz; te[ 5 ] = 1 - ( xx + zz ); te[ 9 ] = yz - wx; te[ 2 ] = xz - wy; te[ 6 ] = yz + wx; te[ 10 ] = 1 - ( xx + yy ); //最后一列 // last column te[ 3 ] = 0; te[ 7 ] = 0; te[ 11 ] = 0; //最后一行 // bottom row te[ 12 ] = 0; te[ 13 ] = 0; te[ 14 ] = 0; te[ 15 ] = 1; return this; //返回新的Matrix4(4x4矩阵) }, /* ///lookAt(eye,center,up)将对象设定为一个视图矩阵。參数都是Vector3对象,该矩阵仅仅会用到eye和center的相对位置。 ///该视图矩阵表示,摄像机在eye位置看向center位置。且向上的向量(这一点稍后解释)为up时的视图矩阵。

///视图矩阵又能够看做摄像机的模型矩阵,所以该函数产生的矩阵又能够表示以下变换:将物体从原点平移至位置center-eye, ///再将其旋转至向上的向量为up。向上的向量up用来固定相机,能够想象当相机固定在一点,镜头朝向固定方向的时候, ///还是能够在一个维度里自由旋转的。up向量固定相机的这个维度。 ///这里的解释摘抄自:http://www.cnblogs.com/yiyezhai/archive/2012/11/29/2791319.html */ ///<summary>lookAt</summary> ///<param name ="eye" type="Vector3">表示相机位置的Vector3三维向量</param> ///<param name ="target" type="Vector3">表示目标的Vector3三维向量</param> ///<param name ="up" type="Vector3">表示向上的Vector3三维向量</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> lookAt: function () { var x = new THREE.Vector3(); var y = new THREE.Vector3(); var z = new THREE.Vector3(); return function ( eye, target, up ) { var te = this.elements; z.subVectors( eye, target ).normalize(); if ( z.length() === 0 ) { z.z = 1; } x.crossVectors( up, z ).normalize(); if ( x.length() === 0 ) { z.x += 0.0001; x.crossVectors( up, z ).normalize(); } y.crossVectors( z, x ); te[ 0 ] = x.x; te[ 4 ] = y.x; te[ 8 ] = z.x; te[ 1 ] = x.y; te[ 5 ] = y.y; te[ 9 ] = z.y; te[ 2 ] = x.z; te[ 6 ] = y.z; te[ 10 ] = z.z; return this; //返回新的Matrix4(4x4矩阵) }; }(), /* ///multiply方法用来将当前Matrix4(4x4矩阵)与參数m相乘.并返回新的Matrix4(4x4矩阵) /// NOTE:这里仅仅接受一个參数,假设传递两个參数请使用.multiplyMatrices( a, b )方法替代,假设有两个參数会自己主动调用.multiplyMatrices( a, b )方法 */ ///<summary>multiply</summary> ///<param name ="m" type="Matrix4(4x4矩阵)">与当前对象元素值相乘的Matrix4(4x4矩阵)</param> ///<param name ="n" type="Matrix4(4x4矩阵)">推断是否有第二个參数w,假设有的话,调用.multiplyMatrices()方法</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> multiply: function ( m, n ) { if ( n !== undefined ) { //推断是否有第二个參数w,假设有的话,调用.multiplyMatrices()方法 // NOTE:这里仅仅接受一个參数,假设传递两个參数请使用.multiplyMatrices( a, b )方法替代, console.warn( ‘THREE.Matrix4: .multiply() now only accepts one argument. Use .multiplyMatrices( a, b ) instead.‘ ); return this.multiplyMatrices( m, n ); //调用.multiplyMatrices()方法,返回新的Matrix4(4x4矩阵),矩阵m和矩阵n相乘 } return this.multiplyMatrices( this, m ); //调用.multiplyMatrices()方法,返回新的Matrix4(4x4矩阵),当前矩阵和矩阵m相乘 }, /* ///multiply方法用来将矩阵a,b相乘,并返回新的Matrix4(4x4矩阵). */ ///<summary>multiplyMatrices</summary> ///<param name ="a" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<param name ="b" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<returns type="Matrix4(4x4矩阵)">返回新的Matrix4(4x4矩阵)</returns> multiplyMatrices: function ( a, b ) { var ae = a.elements; var be = b.elements; var te = this.elements; //将矩阵a,b相乘. var a11 = ae[ 0 ], a12 = ae[ 4 ], a13 = ae[ 8 ], a14 = ae[ 12 ]; var a21 = ae[ 1 ], a22 = ae[ 5 ], a23 = ae[ 9 ], a24 = ae[ 13 ]; var a31 = ae[ 2 ], a32 = ae[ 6 ], a33 = ae[ 10 ], a34 = ae[ 14 ]; var a41 = ae[ 3 ], a42 = ae[ 7 ], a43 = ae[ 11 ], a44 = ae[ 15 ]; var b11 = be[ 0 ], b12 = be[ 4 ], b13 = be[ 8 ], b14 = be[ 12 ]; var b21 = be[ 1 ], b22 = be[ 5 ], b23 = be[ 9 ], b24 = be[ 13 ]; var b31 = be[ 2 ], b32 = be[ 6 ], b33 = be[ 10 ], b34 = be[ 14 ]; var b41 = be[ 3 ], b42 = be[ 7 ], b43 = be[ 11 ], b44 = be[ 15 ]; te[ 0 ] = a11 * b11 + a12 * b21 + a13 * b31 + a14 * b41; te[ 4 ] = a11 * b12 + a12 * b22 + a13 * b32 + a14 * b42; te[ 8 ] = a11 * b13 + a12 * b23 + a13 * b33 + a14 * b43; te[ 12 ] = a11 * b14 + a12 * b24 + a13 * b34 + a14 * b44; te[ 1 ] = a21 * b11 + a22 * b21 + a23 * b31 + a24 * b41; te[ 5 ] = a21 * b12 + a22 * b22 + a23 * b32 + a24 * b42; te[ 9 ] = a21 * b13 + a22 * b23 + a23 * b33 + a24 * b43; te[ 13 ] = a21 * b14 + a22 * b24 + a23 * b34 + a24 * b44; te[ 2 ] = a31 * b11 + a32 * b21 + a33 * b31 + a34 * b41; te[ 6 ] = a31 * b12 + a32 * b22 + a33 * b32 + a34 * b42; te[ 10 ] = a31 * b13 + a32 * b23 + a33 * b33 + a34 * b43; te[ 14 ] = a31 * b14 + a32 * b24 + a33 * b34 + a34 * b44; te[ 3 ] = a41 * b11 + a42 * b21 + a43 * b31 + a44 * b41; te[ 7 ] = a41 * b12 + a42 * b22 + a43 * b32 + a44 * b42; te[ 11 ] = a41 * b13 + a42 * b23 + a43 * b33 + a44 * b43; te[ 15 ] = a41 * b14 + a42 * b24 + a43 * b34 + a44 * b44; return this; //返回新的Matrix4(4x4矩阵) }, /* ///multiply方法用来将矩阵a,b相乘,并返回新Matrix4(4x4矩阵)赋值给数组对象r */ ///<summary>multiplyMatrices</summary> ///<param name ="a" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<param name ="b" type="Matrix4(4x4矩阵)">Matrix4(4x4矩阵)</param> ///<param name ="r" type="Array">数组对象</param> ///<returns type="Array">返回新Matrix4(4x4矩阵)</returns> multiplyToArray: function ( a, b, r ) { var te = this.elements; this.multiplyMatrices( a, b ); //矩阵a,b相乘 //新Matrix4(4x4矩阵)赋值给数组对象 r[ 0 ] = te[ 0 ]; r[ 1 ] = te[ 1 ]; r[ 2 ] = te[ 2 ]; r[ 3 ] = te[ 3 ]; r[ 4 ] = te[ 4 ]; r[ 5 ] = te[ 5 ]; r[ 6 ] = te[ 6 ]; r[ 7 ] = te[ 7 ]; r[ 8 ] = te[ 8 ]; r[ 9 ] = te[ 9 ]; r[ 10 ] = te[ 10 ]; r[ 11 ] = te[ 11 ]; r[ 12 ] = te[ 12 ]; r[ 13 ] = te[ 13 ]; r[ 14 ] = te[ 14 ]; r[ 15 ] = te[ 15 ]; return this; //返回新Matrix4(4x4矩阵) }, /* ///multiplyScalar方法用来将Matrix4(4x4矩阵)的元素直接与參数s相乘.并返回新的Matrix4(4x4矩阵). /// NOTE:这里传递的參数s是一个标量. */ ///<summary>multiplyScalar</summary> ///<param name ="s" type="number">与当前Matrix4(4x4矩阵)对象的值相乘的标量,数值</param> ///<returns type="Matrix4">返回新的Matrix4(4x4矩阵)</returns> multiplyScalar: function ( s ) { var te = this.elements; te[ 0 ] *= s; te[ 4 ] *= s; te[ 8 ] *= s; te[ 12 ] *= s; te[ 1 ] *= s; te[ 5 ] *= s; te[ 9 ] *= s; te[ 13 ] *= s; te[ 2 ] *= s; te[ 6 ] *= s; te[ 10 ] *= s; te[ 14 ] *= s; te[ 3 ] *= s; te[ 7 ] *= s; te[ 11 ] *= s; te[ 15 ] *= s; return this; //返回新的Matrix4(4x4矩阵) }, /* ///multiplyVector3方法用来将3x3矩阵和一个Vector3(三维向量)相乘.并返回新Matrix4(4x4矩阵)对象. /// NOTE:multiplyVector3方法已经被删除使用vector.applyMatrix4( matrix )方法替换,这里保留是为了向下兼容. /// NOTE:multiplyVector3方法经经常使用来应用某种变换. */ ///<summary>multiplyVector3</summary> ///<param name ="vector" type="Vector3">三维向量</param> ///<returns type="Matrix4">并返回新的Matrix4(4x4矩阵)对象</returns> multiplyVector3: function ( vector ) { // 提示用户multiplyVector3方法已经被删除使用vector.applyMatrix4( matrix )方法替换,这里保留是为了向下兼容. console.warn( ‘THREE.Matrix4: .multiplyVector3() has been removed. Use vector.applyMatrix4( matrix ) or vector.applyProjection( matrix ) instead.‘ ); return vector.applyProjection( this ); //并返回新的Matrix4(4x4矩阵)对象 }, /* ///multiplyVector4方法用来将3x3矩阵和一个Vector4(四维向量)相乘.并返回新Matrix4(4x4矩阵)对象. /// NOTE:multiplyVector4方法已经被删除使用vector.applyMatrix4( matrix )方法替换,这里保留是为了向下兼容. /// NOTE:multiplyVector4方法经经常使用来应用某种变换. */ ///<summary>multiplyVector4</summary> ///<param name ="vector" type="Vector4">四维向量</param> ///<returns type="Matrix4">并返回新的Matrix4(4x4矩阵)对象</returns> multiplyVector4: function ( vector ) { // 提示用户multiplyVector4方法已经被删除使用vector.applyMatrix4( matrix )方法替换,这里保留是为了向下兼容. console.warn( ‘THREE.Matrix4: .multiplyVector4() has been removed. Use vector.applyMatrix4( matrix ) instead.‘ ); return vector.applyMatrix4( this ); //并返回新的Matrix4(4x4矩阵)对象 }, /* ///multiplyVector3Array方法用来将数组a和一个Vector3(三维向量)相乘.并返回新的数组对象. /// NOTE:multiplyVector3Array方法已经被删除使用matrix.applyToVector3Array( array )方法替换,这里保留是为了向下兼容. /// NOTE:multiplyVector3Array方法经经常使用来应用某种变换. */ ///<summary>multiplyVector3Array</summary> ///<param name ="a" type="Array">数组对象</param> ///<returns type="Array">并返回新的数组对象</returns> multiplyVector3Array: function ( a ) { // 提示用户multiplyVector3Array方法已经被删除使用matrix.applyToVector3Array( array )方法替换,这里保留是为了向下兼容. console.warn( ‘THREE.Matrix4: .multiplyVector3Array() has been renamed. Use matrix.applyToVector3Array( array ) instead.‘ ); return this.applyToVector3Array( a ); //并返回新的Matrix4(4x4矩阵)对象 }, /* ///applyToVector3Array方法用来将当前矩阵应用到一个三维向量,并将结果转换成一个数组,返回数组对象. /// NOTE:applyToVector3Array方法经经常使用来对三维向量应用某种变换. 參数offset,length用来对不同长度的数组应用变换. /// */ ///<summary>applyMatrix4</summary> ///<param name ="array" type="Array">数组对象</param> ///<param name ="offset" type="Number">偏移量</param> ///<param name ="length" type="Number">长度</param> ///<returns type="Array">并返回新的数组对象</returns> applyToVector3Array: function () { var v1 = new THREE.Vector3(); return function ( array, offset, length ) { if ( offset === undefined ) offset = 0; if ( length === undefined ) length = array.length; for ( var i = 0, j = offset, il; i < length; i += 3, j += 3 ) { v1.x = array[ j ]; v1.y = array[ j + 1 ]; v1.z = array[ j + 2 ]; v1.applyMatrix4( this ); array[ j ] = v1.x; array[ j + 1 ] = v1.y; array[ j + 2 ] = v1.z; } return array; //并返回新的数组对象 }; }(), /* ///rotateAxis方法对參数v三维向量的应用一个旋转变换 /// NOTE:rotateAxis方法已经被删除使用Vector3.transformDirection( matrix )方法替换,这里保留是为了向下兼容. */ ///<summary>rotateAxis</summary> ///<param name ="v" type="Vector3">仿射矩阵</param> ///<returns type="Vector3">返回新坐标值的三维向量</returns> rotateAxis: function ( v ) { //提示用户rotateAxis方法已经被删除使用Vector3.transformDirection( matrix )方法替换,这里保留是为了向下兼容. console.warn( ‘THREE.Matrix4: .rotateAxis() has been removed. Use Vector3.transformDirection( matrix ) instead.‘ ); v.transformDirection( this ); //调用Vector3.transformDirection( matrix ) 方法,对向量应用旋转变换 }, /*crossVector方法 ///crossVector方法将返回两个交叉乘积,调用者变为a,b的叉乘。

叉乘是一个向量,垂直于參与叉乘的两个向量并呈右手螺旋法则。 /// 返回为同一时候垂直于两个參数向量的向量,方向可朝上也可朝下,由两向量夹角的方向决定。

/// NOTE:crossVector方法已经被删除使用vector.applyMatrix4( matrix )方法替换,这里保留是为了向下兼容. /// NOTE:借助右手定则辅助推断方向。參考:http://zh.wikipedia.org/zh/%E5%90%91%E9%87%8F%E7%A7%AF /// 叉乘是一种在向量空间中向量的二元运算。与点乘不同,它的运算结果是一个伪向量而不是一个标量。 /// 叉乘的运算结果叫叉积(即交叉乘积)、外积或向量积。

叉积与原来的两个向量都垂直。

1、理论知识 数学上的定义:c=axb【注:粗体小写字母表示向量】当中a,b,c均为向量。即两个向量的叉积得到的还是向量! 性质1:c⊥a,c⊥b,即向量c垂直与向量a,b所在的平面。 性质2:模长|c|=|a||b|sin<a,b> 性质3:满足右手法则。从这点我们有axb ≠ bxa,而axb = - bxa。所以我们能够使用叉积的正负值来推断向量a,b的相对位置。 即向量b是处于向量a的顺时针方向还是逆时针方向。 */ ///<summary>crossVector</summary> ///<param name ="vector" type="Vector3">三维向量</param> ///<returns type="Vector3">三维向量</returns> crossVector: function ( vector ) { //提示用户crossVector方法已经被删除使用vector.applyMatrix4( matrix )方法替换,这里保留是为了向下兼容. console.warn( ‘THREE.Matrix4: .crossVector() has been removed. Use vector.applyMatrix4( matrix ) instead.‘ ); return vector.applyMatrix4( this ); //调用Vector3.applyMatrix4( matrix ) 方法,返回參数vector和当前矩阵的差乘. }, /* ///determinant方法用来获得Matrix4(4x4矩阵)的行列式 /// NOTE:通过求解行列式值的方式来推断矩阵的逆矩阵是否存在(行列式的值不等于0,表示该矩阵有逆矩阵). */ ///<summary>determinant</summary> ///<returns type="Number">返回Matrix4(4x4矩阵)的四阶行列式</returns> determinant: function () { var te = this.elements; var n11 = te[ 0 ], n12 = te[ 4 ], n13 = te[ 8 ], n14 = te[ 12 ]; var n21 = te[ 1 ], n22 = te[ 5 ], n23 = te[ 9 ], n24 = te[ 13 ]; var n31 = te[ 2 ], n32 = te[ 6 ], n33 = te[ 10 ], n34 = te[ 14 ]; var n41 = te[ 3 ], n42 = te[ 7 ], n43 = te[ 11 ], n44 = te[ 15 ]; //TODO: make this more efficient //( based on http://www.euclideanspace.com/maths/algebra/matrix/functions/inverse/fourD/index.htm ) return ( n41 * ( + n14 * n23 * n32 - n13 * n24 * n32 - n14 * n22 * n33 + n12 * n24 * n33 + n13 * n22 * n34 - n12 * n23 * n34 ) + n42 * ( + n11 * n23 * n34 - n11 * n24 * n33 + n14 * n21 * n33 - n13 * n21 * n34 + n13 * n24 * n31 - n14 * n23 * n31 ) + n43 * ( + n11 * n24 * n32 - n11 * n22 * n34 - n14 * n21 * n32 + n12 * n21 * n34 + n14 * n22 * n31 - n12 * n24 * n31 ) + n44 * ( - n13 * n22 * n31 - n11 * n23 * n32 + n11 * n22 * n33 + n13 * n21 * n32 - n12 * n21 * n33 + n12 * n23 * n31 ) //返回Matrix4(4x4矩阵)的四阶行列式 ); }, /* ///transpose方法用来获得Matrix4(4x4矩阵)的转置矩阵. /// NOTE:一个mxn的矩阵的转置矩阵式nxm矩阵,就是矩阵的行和列交换. /// 比如: /// /// -- -- -- -- T /// | 1 2 3 | | 1 4 7 | /// matrix A = | 4 5 6 | = | 2 5 8 | /// | 7 8 9 | | 3 6 9 | /// -- -- -- -- */ ///<summary>transpose</summary> ///<returns type="Matrix4">返回Matrix4(4x4矩阵)的转置矩阵.</returns> transpose: function () { var te = this.elements; var tmp; tmp = te[ 1 ]; te[ 1 ] = te[ 4 ]; te[ 4 ] = tmp; tmp = te[ 2 ]; te[ 2 ] = te[ 8 ]; te[ 8 ] = tmp; tmp = te[ 6 ]; te[ 6 ] = te[ 9 ]; te[ 9 ] = tmp; tmp = te[ 3 ]; te[ 3 ] = te[ 12 ]; te[ 12 ] = tmp; tmp = te[ 7 ]; te[ 7 ] = te[ 13 ]; te[ 13 ] = tmp; tmp = te[ 11 ]; te[ 11 ] = te[ 14 ]; te[ 14 ] = tmp; return this; //返回Matrix4(4x4矩阵)的转置矩阵. }, /* ///flattenToArrayOffset方法通过參数offset指定偏移量,将矩阵展开到数组(參数array)中,返回新的数组. /// NOTE:flattenToArrayOffset方法能够用在将3x3矩阵变换成4x4矩阵中. /// -- -- /// | 1 2 3 | /// matrix A = | 4 5 6 | => flattenToArrayOffset(arrary,3) => array(0,0,0,0,1,2,3,0,0,0,0,4,5,6,0,0,0,0,7,8,9) /// | 7 8 9 | /// -- -- */ ///<summary>flattenToArrayOffset</summary> ///<param name ="array" type="Array">Array数组对象</param> ///<param name ="offset" type="Number">偏移量</param> ///<returns type="Matrix4">返回包括矩阵元素的数组</returns> flattenToArrayOffset: function ( array, offset ) { var te = this.elements; array[ offset ] = te[ 0 ]; array[ offset + 1 ] = te[ 1 ]; array[ offset + 2 ] = te[ 2 ]; array[ offset + 3 ] = te[ 3 ]; array[ offset + 4 ] = te[ 4 ]; array[ offset + 5 ] = te[ 5 ]; array[ offset + 6 ] = te[ 6 ]; array[ offset + 7 ] = te[ 7 ]; array[ offset + 8 ] = te[ 8 ]; array[ offset + 9 ] = te[ 9 ]; array[ offset + 10 ] = te[ 10 ]; array[ offset + 11 ] = te[ 11 ]; array[ offset + 12 ] = te[ 12 ]; array[ offset + 13 ] = te[ 13 ]; array[ offset + 14 ] = te[ 14 ]; array[ offset + 15 ] = te[ 15 ]; return array; //返回包括矩阵元素的数组 }, /* ///getPosition方法将当前矩阵中代表位置的元素值设置给三维向量 /// NOTE:getPosition方法已经被删除使用vector.setFromMatrixPosition( matrix )方法替换,这里保留是为了向下兼容. */ ///<summary>getPosition</summary> ///<returns type="Vector3">返回三维向量</returns> getPosition: function () { var v1 = new THREE.Vector3(); return function () { console.warn( ‘THREE.Matrix4: .getPosition() has been removed. Use Vector3.setFromMatrixPosition( matrix ) instead.‘ ); var te = this.elements; return v1.set( te[ 12 ], te[ 13 ], te[ 14 ] ); //返回三维向量 }; }(), /* ///setPosition方法将当前矩阵中代表位置的元素值设置给三维向量 */ ///<summary>setPosition</summary> ///<param name ="v" type="Vector3">偏移量</param> ///<returns type="Matrix4">返回新的Matrix4(4x4矩阵)</returns> setPosition: function ( v ) { var te = this.elements; te[ 12 ] = v.x; te[ 13 ] = v.y; te[ 14 ] = v.z; return this; //返回新的Matrix4(4x4矩阵) }, /* ///getInverse方法用来获得Matrix4(4x4矩阵)的逆矩阵. /// NOTE:逆矩阵与当前矩阵相乘得到单位矩阵. */ ///<summary>multiplyScalar</summary> ///<param name ="matrix" type="Matrix4">THREE.Matrix4</param> ///<param name ="throwOnInvertible" type="Number">异常标志</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵)的逆矩阵.</returns> getInverse: function ( m, throwOnInvertible ) { // based on http://www.euclideanspace.com/maths/algebra/matrix/functions/inverse/fourD/index.htm var te = this.elements; var me = m.elements; var n11 = me[ 0 ], n12 = me[ 4 ], n13 = me[ 8 ], n14 = me[ 12 ]; var n21 = me[ 1 ], n22 = me[ 5 ], n23 = me[ 9 ], n24 = me[ 13 ]; var n31 = me[ 2 ], n32 = me[ 6 ], n33 = me[ 10 ], n34 = me[ 14 ]; var n41 = me[ 3 ], n42 = me[ 7 ], n43 = me[ 11 ], n44 = me[ 15 ]; te[ 0 ] = n23 * n34 * n42 - n24 * n33 * n42 + n24 * n32 * n43 - n22 * n34 * n43 - n23 * n32 * n44 + n22 * n33 * n44; te[ 4 ] = n14 * n33 * n42 - n13 * n34 * n42 - n14 * n32 * n43 + n12 * n34 * n43 + n13 * n32 * n44 - n12 * n33 * n44; te[ 8 ] = n13 * n24 * n42 - n14 * n23 * n42 + n14 * n22 * n43 - n12 * n24 * n43 - n13 * n22 * n44 + n12 * n23 * n44; te[ 12 ] = n14 * n23 * n32 - n13 * n24 * n32 - n14 * n22 * n33 + n12 * n24 * n33 + n13 * n22 * n34 - n12 * n23 * n34; te[ 1 ] = n24 * n33 * n41 - n23 * n34 * n41 - n24 * n31 * n43 + n21 * n34 * n43 + n23 * n31 * n44 - n21 * n33 * n44; te[ 5 ] = n13 * n34 * n41 - n14 * n33 * n41 + n14 * n31 * n43 - n11 * n34 * n43 - n13 * n31 * n44 + n11 * n33 * n44; te[ 9 ] = n14 * n23 * n41 - n13 * n24 * n41 - n14 * n21 * n43 + n11 * n24 * n43 + n13 * n21 * n44 - n11 * n23 * n44; te[ 13 ] = n13 * n24 * n31 - n14 * n23 * n31 + n14 * n21 * n33 - n11 * n24 * n33 - n13 * n21 * n34 + n11 * n23 * n34; te[ 2 ] = n22 * n34 * n41 - n24 * n32 * n41 + n24 * n31 * n42 - n21 * n34 * n42 - n22 * n31 * n44 + n21 * n32 * n44; te[ 6 ] = n14 * n32 * n41 - n12 * n34 * n41 - n14 * n31 * n42 + n11 * n34 * n42 + n12 * n31 * n44 - n11 * n32 * n44; te[ 10 ] = n12 * n24 * n41 - n14 * n22 * n41 + n14 * n21 * n42 - n11 * n24 * n42 - n12 * n21 * n44 + n11 * n22 * n44; te[ 14 ] = n14 * n22 * n31 - n12 * n24 * n31 - n14 * n21 * n32 + n11 * n24 * n32 + n12 * n21 * n34 - n11 * n22 * n34; te[ 3 ] = n23 * n32 * n41 - n22 * n33 * n41 - n23 * n31 * n42 + n21 * n33 * n42 + n22 * n31 * n43 - n21 * n32 * n43; te[ 7 ] = n12 * n33 * n41 - n13 * n32 * n41 + n13 * n31 * n42 - n11 * n33 * n42 - n12 * n31 * n43 + n11 * n32 * n43; te[ 11 ] = n13 * n22 * n41 - n12 * n23 * n41 - n13 * n21 * n42 + n11 * n23 * n42 + n12 * n21 * n43 - n11 * n22 * n43; te[ 15 ] = n12 * n23 * n31 - n13 * n22 * n31 + n13 * n21 * n32 - n11 * n23 * n32 - n12 * n21 * n33 + n11 * n22 * n33; var det = n11 * te[ 0 ] + n21 * te[ 4 ] + n31 * te[ 8 ] + n41 * te[ 12 ]; //获得參数matrix行列式的值 if ( det == 0 ) { // 没有逆矩阵 var msg = "Matrix4.getInverse(): can‘t invert matrix, determinant is 0"; //提示用户该矩阵没有逆矩阵 if ( throwOnInvertible || false ) { throw new Error( msg ); } else { console.warn( msg ); } this.identity(); //获得一个单位矩阵 return this; //返回单位矩阵 } this.multiplyScalar( 1 / det ); //除以行列式得到逆矩阵 return this; //返回Matrix4(4x4矩阵)的逆矩阵. }, /* ///translate方法用来变换Matrix4(4x4矩阵). /// NOTE:translate方法已经删除. */ ///<summary>translate</summary> ///<param name ="v" type="Vector3">THREE.Vecter3</param> ///<returns type="Matrix4">返回带有新位置信息的Matrix4(4x4矩阵).</returns> translate: function ( v ) { //提示用户translate()方法已经删除. console.warn( ‘THREE.Matrix4: .translate() has been removed.‘ ); }, /* ///rotateX方法用来变换Matrix4(4x4矩阵)的x轴. /// NOTE:rotateX方法已经删除. */ ///<summary>rotateX</summary> ///<param name ="angle" type="Number">角度</param> ///<returns type="Matrix4">返回带有新的Matrix4(4x4矩阵).</returns> rotateX: function ( angle ) { //提示用户rotateX()方法已经删除. console.warn( ‘THREE.Matrix4: .rotateX() has been removed.‘ ); }, /* ///rotateY方法用来变换Matrix4(4x4矩阵)的Y轴. /// NOTE:rotateX方法已经删除. */ ///<summary>rotateY</summary> ///<param name ="angle" type="Number">角度</param> ///<returns type="Matrix4">返回带有新的Matrix4(4x4矩阵).</returns> rotateY: function ( angle ) { //提示用户rotateY()方法已经删除. console.warn( ‘THREE.Matrix4: .rotateY() has been removed.‘ ); }, /* ///rotateZ方法用来变换Matrix4(4x4矩阵)的Z轴. /// NOTE:rotateZ方法已经删除. */ ///<summary>rotateZ</summary> ///<param name ="angle" type="Number">角度</param> ///<returns type="Matrix4">返回带有新的Matrix4(4x4矩阵).</returns> rotateZ: function ( angle ) { //提示用户rotateZ()方法已经删除. console.warn( ‘THREE.Matrix4: .rotateZ() has been removed.‘ ); }, /* ///rotateByAxis方法用来变换Matrix4(4x4矩阵)的随意轴. /// NOTE:rotateByAxis方法已经删除. */ ///<summary>rotateByAxis</summary> ///<param name ="axis" type="Vector3">随意轴</param> ///<param name ="angle" type="Number">角度</param> ///<returns type="Matrix4">返回带有新的Matrix4(4x4矩阵).</returns> rotateByAxis: function ( axis, angle ) { //提示用户rotateByAxis()方法已经删除. console.warn( ‘THREE.Matrix4: .rotateByAxis() has been removed.‘ ); }, /* ///scale方法通过预先计算比例向量,将指定的比例向量应用到此 Matrix4(4x4矩阵)。 */ ///<summary>scale</summary> ///<param name ="v" type="Vector3">比例向量Vector3</param> ///<returns type="Matrix4">返回新的Matrix4(4x4矩阵).</returns> scale: function ( v ) { var te = this.elements; var x = v.x, y = v.y, z = v.z; te[ 0 ] *= x; te[ 4 ] *= y; te[ 8 ] *= z; te[ 1 ] *= x; te[ 5 ] *= y; te[ 9 ] *= z; te[ 2 ] *= x; te[ 6 ] *= y; te[ 10 ] *= z; te[ 3 ] *= x; te[ 7 ] *= y; te[ 11 ] *= z; return this; //返回新的Matrix4(4x4矩阵). }, getMaxScaleOnAxis: function () { var te = this.elements; var scaleXSq = te[ 0 ] * te[ 0 ] + te[ 1 ] * te[ 1 ] + te[ 2 ] * te[ 2 ]; var scaleYSq = te[ 4 ] * te[ 4 ] + te[ 5 ] * te[ 5 ] + te[ 6 ] * te[ 6 ]; var scaleZSq = te[ 8 ] * te[ 8 ] + te[ 9 ] * te[ 9 ] + te[ 10 ] * te[ 10 ]; return Math.sqrt( Math.max( scaleXSq, Math.max( scaleYSq, scaleZSq ) ) ); }, /* ///makeTranslation方法依据x, y, z生成平移矩阵. */ ///<summary>makeTranslation</summary> ///<param name ="x" type="Number">x分量</param> ///<param name ="y" type="Number">y分量</param> ///<param name ="z" type="Number">z分量</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),平移矩阵.</returns> makeTranslation: function ( x, y, z ) { this.set( 1, 0, 0, x, 0, 1, 0, y, 0, 0, 1, z, 0, 0, 0, 1 ); return this; //返回Matrix4(4x4矩阵),平移矩阵 }, /* ///makeRotationX方法生成绕x轴转theta弧度的旋转矩阵 /// TODO:这里是弧度还是角度,有待确认. */ ///<summary>makeRotationX</summary> ///<param name ="theta" type="Number">弧度</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),旋转矩阵.</returns> makeRotationX: function ( theta ) { var c = Math.cos( theta ), s = Math.sin( theta ); this.set( 1, 0, 0, 0, 0, c, - s, 0, 0, s, c, 0, 0, 0, 0, 1 ); return this; //返回Matrix4(4x4矩阵),旋转矩阵. }, /* ///makeRotationY方法生成绕y轴转theta弧度的旋转矩阵 /// TODO:这里是弧度还是角度,有待确认. */ ///<summary>makeRotationY</summary> ///<param name ="theta" type="Number">弧度</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),旋转矩阵.</returns> makeRotationY: function ( theta ) { var c = Math.cos( theta ), s = Math.sin( theta ); this.set( c, 0, s, 0, 0, 1, 0, 0, - s, 0, c, 0, 0, 0, 0, 1 ); return this; //返回Matrix4(4x4矩阵),旋转矩阵. }, /* ///makeRotationZ方法生成绕z轴转theta弧度的旋转矩阵 /// TODO:这里是弧度还是角度,有待确认. */ ///<summary>makeRotationZ</summary> ///<param name ="theta" type="Number">弧度</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),旋转矩阵.</returns> makeRotationZ: function ( theta ) { var c = Math.cos( theta ), s = Math.sin( theta ); this.set( c, - s, 0, 0, s, c, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 ); return this; //返回Matrix4(4x4矩阵),旋转矩阵. }, /* ///makeRotationAxis方法生成绕随意轴转angle弧度的旋转矩阵 /// TODO:这里是弧度还是角度,有待确认. */ ///<summary>makeRotationAxis</summary> ///<param name ="axis" type="Vector3"> 转轴向量(axis必须是单位向量)</param> ///<param name ="theta" type="Number">弧度</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),旋转矩阵.</returns> makeRotationAxis: function ( axis, angle ) { // Based on http://www.gamedev.net/reference/articles/article1199.asp var c = Math.cos( angle ); var s = Math.sin( angle ); var t = 1 - c; var x = axis.x, y = axis.y, z = axis.z; var tx = t * x, ty = t * y; this.set( tx * x + c, tx * y - s * z, tx * z + s * y, 0, tx * y + s * z, ty * y + c, ty * z - s * x, 0, tx * z - s * y, ty * z + s * x, t * z * z + c, 0, 0, 0, 0, 1 ); return this; //返回Matrix4(4x4矩阵),旋转矩阵. }, /* ///makeScale方法依据x, y, z生成缩放矩阵. */ ///<summary>makeScale</summary> ///<param name ="x" type="Number">x分量</param> ///<param name ="y" type="Number">y分量</param> ///<param name ="z" type="Number">z分量</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),缩放矩阵.</returns> makeScale: function ( x, y, z ) { this.set( x, 0, 0, 0, 0, y, 0, 0, 0, 0, z, 0, 0, 0, 0, 1 ); return this; //返回Matrix4(4x4矩阵),缩放矩阵. }, /* ///compose方法设置变换矩阵的平移、旋转和缩放设置 */ ///<summary>compose</summary> ///<param name ="position" type="Vector3">平移向量</param> ///<param name ="quaternion" type="Vector3">旋转向量</param> ///<param name ="scale" type="Vector3">缩放向量</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),变换矩阵.</returns> compose: function ( position, quaternion, scale ) { this.makeRotationFromQuaternion( quaternion ); this.scale( scale ); this.setPosition( position ); return this; //返回Matrix4(4x4矩阵),变换矩阵. }, /* ///decompose方法将转换矩阵的平移、旋转和缩放设置作为由三个 Vector3 对象组成的矢量返回。

第一个 Vector3 对象容纳平移元素。

第二个 Vector3 对象容纳旋转元素。第三个 Vector3 对象容纳缩放元素。 */ ///<summary>decompose</summary> ///<param name ="position" type="Vector3">平移向量</param> ///<param name ="quaternion" type="Vector3">旋转向量</param> ///<param name ="scale" type="Vector3">缩放向量</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),变换矩阵.</returns> decompose: function () { var vector = new THREE.Vector3(); var matrix = new THREE.Matrix4(); return function ( position, quaternion, scale ) { var te = this.elements; var sx = vector.set( te[ 0 ], te[ 1 ], te[ 2 ] ).length(); var sy = vector.set( te[ 4 ], te[ 5 ], te[ 6 ] ).length(); var sz = vector.set( te[ 8 ], te[ 9 ], te[ 10 ] ).length(); // if determine is negative, we need to invert one scale // 假设行列式是负数,把比例转换成正数 var det = this.determinant(); if ( det < 0 ) { sx = - sx; } position.x = te[ 12 ]; position.y = te[ 13 ]; position.z = te[ 14 ]; // scale the rotation part // 缩放有关旋转的元素 matrix.elements.set( this.elements ); // at this point matrix is incomplete so we can‘t use .copy() //这个表示点的矩阵是不完整的,我们不能使用copy()方法 var invSX = 1 / sx; var invSY = 1 / sy; var invSZ = 1 / sz; matrix.elements[ 0 ] *= invSX; matrix.elements[ 1 ] *= invSX; matrix.elements[ 2 ] *= invSX; matrix.elements[ 4 ] *= invSY; matrix.elements[ 5 ] *= invSY; matrix.elements[ 6 ] *= invSY; matrix.elements[ 8 ] *= invSZ; matrix.elements[ 9 ] *= invSZ; matrix.elements[ 10 ] *= invSZ; quaternion.setFromRotationMatrix( matrix ); scale.x = sx; scale.y = sy; scale.z = sz; return this; //返回Matrix4(4x4矩阵),变换矩阵 }; }(), /* ///makeFrustum方法依据left, right, bottom, top, near, far生成透视投影矩阵,Frustum平截头体 */ ///<summary>makeFrustum</summary> ///<param name ="left" type="Number">指明相对于垂直平面的左側坐标位置</param> ///<param name ="right" type="Number">指明相对于垂直平面的右側坐标位置</param> ///<param name ="bottom" type="Number">指明相对于垂直平面的底部坐标位置</param> ///<param name ="top" type="Number">指明相对于垂直平面的顶部坐标位置</param> ///<param name ="near" type="Number">指明相对于深度剪切面的近的距离,必须为正数</param> ///<param name ="far" type="Number">指明相对于深度剪切面的远的距离,必须为正数</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),透视投影矩阵.</returns> makeFrustum: function ( left, right, bottom, top, near, far ) { var te = this.elements; var x = 2 * near / ( right - left ); var y = 2 * near / ( top - bottom ); var a = ( right + left ) / ( right - left ); var b = ( top + bottom ) / ( top - bottom ); var c = - ( far + near ) / ( far - near ); var d = - 2 * far * near / ( far - near ); te[ 0 ] = x; te[ 4 ] = 0; te[ 8 ] = a; te[ 12 ] = 0; te[ 1 ] = 0; te[ 5 ] = y; te[ 9 ] = b; te[ 13 ] = 0; te[ 2 ] = 0; te[ 6 ] = 0; te[ 10 ] = c; te[ 14 ] = d; te[ 3 ] = 0; te[ 7 ] = 0; te[ 11 ] = - 1; te[ 15 ] = 0; return this; //返回Matrix4(4x4矩阵),透视投影矩阵 }, /* ///makePerspective方法依据 fov, aspect, near, far 生成透视投影矩阵,对makeFrustu()方法的封装,适配人们习惯的表达方式. */ ///<summary>makePerspective</summary> ///<param name ="fov" type="Number">指明相机的可视角度</param> ///<param name ="aspect" type="Number">指明相机可视范围的长宽比</param> ///<param name ="near" type="Number">指明相对于深度剪切面的近的距离,必须为正数</param> ///<param name ="far" type="Number">指明相对于深度剪切面的远的距离,必须为正数</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),透视投影矩阵.</returns> makePerspective: function ( fov, aspect, near, far ) { var ymax = near * Math.tan( THREE.Math.degToRad( fov * 0.5 ) ); var ymin = - ymax; var xmin = ymin * aspect; var xmax = ymax * aspect; return this.makeFrustum( xmin, xmax, ymin, ymax, near, far ); //调用makeFrustum()方法,返回透视投影矩阵. }, /* ///makeOrthographic方法依据 left, right, top, bottom, near, far 生成正交矩阵. */ ///<summary>makePerspective</summary> ///<param name ="left" type="Number">指明相对于垂直平面的左側坐标位置</param> ///<param name ="right" type="Number">指明相对于垂直平面的右側坐标位置</param> ///<param name ="bottom" type="Number">指明相对于垂直平面的底部坐标位置</param> ///<param name ="top" type="Number">指明相对于垂直平面的顶部坐标位置</param> ///<param name ="near" type="Number">指明相对于深度剪切面的近的距离,必须为正数</param> ///<param name ="far" type="Number">指明相对于深度剪切面的远的距离,必须为正数</param> ///<returns type="Matrix4">返回Matrix4(4x4矩阵),正交投影矩阵.</returns> makeOrthographic: function ( left, right, top, bottom, near, far ) { var te = this.elements; var w = right - left; var h = top - bottom; var p = far - near; var x = ( right + left ) / w; var y = ( top + bottom ) / h; var z = ( far + near ) / p; te[ 0 ] = 2 / w; te[ 4 ] = 0; te[ 8 ] = 0; te[ 12 ] = - x; te[ 1 ] = 0; te[ 5 ] = 2 / h; te[ 9 ] = 0; te[ 13 ] = - y; te[ 2 ] = 0; te[ 6 ] = 0; te[ 10 ] = - 2 / p; te[ 14 ] = - z; te[ 3 ] = 0; te[ 7 ] = 0; te[ 11 ] = 0; te[ 15 ] = 1; return this; //返回Matrix4(4x4矩阵),正交投影矩阵. }, /*fromArray方法 ///fromArray方法将存储Matrix4(4x4矩阵)元素值的数组赋值给当前Matrix4(4x4矩阵)对象 */ ///<summary>fromArray</summary> ///<param name ="array" type="Array">Matrix4(4x4矩阵)元素值的数组array</param> ///<returns type="Matrix4">返回新的Matrix4(4x4矩阵)</returns> fromArray: function ( array ) { this.elements.set( array ); //调用set方法,将数组赋值给当前Matrix4(4x4矩阵)对象 return this; //返回新的Matrix4(4x4矩阵) }, /*toArray方法 ///toArray方法将当前Matrix4(4x4矩阵)的元素值赋值给数组array.返回一个数组对象. */ ///<summary>toArray</summary> ///<returns type="Array">返回含有Matrix4(4x4矩阵)元素值的数组array</returns> toArray: function () { var te = this.elements; return [ te[ 0 ], te[ 1 ], te[ 2 ], te[ 3 ], te[ 4 ], te[ 5 ], te[ 6 ], te[ 7 ], te[ 8 ], te[ 9 ], te[ 10 ], te[ 11 ], te[ 12 ], te[ 13 ], te[ 14 ], te[ 15 ] ]; //返回含有Matrix4(4x4矩阵)元素值的数组array }, /*clone方法 ///clone方法克隆一个Matrix4(4x4矩阵)对象. */ ///<summary>clone</summary> ///<returns type="Matrix4(4x4矩阵)">返回克隆的Matrix4(4x4矩阵)对象</returns> clone: function () { var te = this.elements; return new THREE.Matrix4( te[ 0 ], te[ 4 ], te[ 8 ], te[ 12 ], te[ 1 ], te[ 5 ], te[ 9 ], te[ 13 ], te[ 2 ], te[ 6 ], te[ 10 ], te[ 14 ], te[ 3 ], te[ 7 ], te[ 11 ], te[ 15 ] ); //返回克隆的Matrix4(4x4矩阵)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。


下面代码是THREE.JS 源代码文件里Math/Matrix4.js文件的凝视.

很多其它更新在 : https://github.com/omni360/three.js.sourcecode/blob/master/Three.js

three.js 源代码凝视(九)Math/Matrix4.js

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原文地址:http://www.cnblogs.com/cxchanpin/p/6852938.html

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