From 7534bd7acc822dea641b1547cd955801920055aa Mon Sep 17 00:00:00 2001 From: Nivesh Rajbhandari Date: Thu, 2 Feb 2012 13:55:55 -0800 Subject: Adding legal attribution for decompose matrix routine. Signed-off-by: Nivesh Rajbhandari --- js/helper-classes/3D/math-utils.js | 54 ++++++++++++++++++++------------------ 1 file changed, 29 insertions(+), 25 deletions(-) (limited to 'js/helper-classes/3D/math-utils.js') diff --git a/js/helper-classes/3D/math-utils.js b/js/helper-classes/3D/math-utils.js index 49c77c41..71ed62a0 100644 --- a/js/helper-classes/3D/math-utils.js +++ b/js/helper-classes/3D/math-utils.js @@ -891,36 +891,32 @@ var MathUtilsClass = exports.MathUtilsClass = Object.create(Object.prototype, { } }, +/** +* decompose matrix in javascript found at https://github.com/joelambert/morf/blob/master/js/src/WebkitCSSMatrix.ext.js +* used with permission from Joe Lambert: "as long as the original licence text and attribution is left in then you're +* good to use it as you see fit." +* +* WebKitCSSMatrix Extensions +* +* Copyright 2011, Joe Lambert (http://www.joelambert.co.uk) +* Free to use under the MIT license. +* http://joelambert.mit-license.org/ +*/ + +/** +* Decomposes the matrix into its component parts. +* A Javascript implementation of the pseudo code available from http://www.w3.org/TR/css3-2d-transforms/#matrix-decomposition +* @author Joe Lambert +* @returns {Object} An object with each of the components of the matrix (perspective, translate, skew, scale, rotate) or identity matrix on failure +*/ + // Input: matrix ; a 4x4 matrix // Output: translation ; a 3 component vector // rotation ; Euler angles, represented as a 3 component vector // scale ; a 3 component vector // skew ; skew factors XY,XZ,YZ represented as a 3 component vector // perspective ; a 4 component vector -// Returns false if the matrix cannot be decomposed, an object with the above output values if it can -// -// Supporting functions (point is a 3 component vector, matrix is a 4x4 matrix): -// float determinant(matrix) returns the 4x4 determinant of the matrix -// matrix inverse(matrix) returns the inverse of the passed matrix -// matrix transpose(matrix) returns the transpose of the passed matrix -// point multVecMatrix(point, matrix) multiplies the passed point by the passed matrix -// and returns the transformed point -// float length(point) returns the length of the passed vector -// point normalize(point) normalizes the length of the passed point to 1 -// float dot(point, point) returns the dot product of the passed points -// float cos(float) returns the cosine of the passed angle in radians -// float asin(float) returns the arcsine in radians of the passed value -// float atan2(float y, float x) returns the principal value of the arc tangent of -// y/x, using the signs of both arguments to determine -// the quadrant of the return value -// -// Decomposition also makes use of the following function: -// point combine(point a, point b, float ascl, float bscl) -// result[0] = (ascl * a[0]) + (bscl * b[0]) -// result[1] = (ascl * a[1]) + (bscl * b[1]) -// result[2] = (ascl * a[2]) + (bscl * b[2]) -// return result -// +// Returns false if the matrix cannot be decomposed. An object with the above output values if it can. decomposeMatrix2: { value: function(m) { @@ -1077,7 +1073,6 @@ var MathUtilsClass = exports.MathUtilsClass = Object.create(Object.prototype, { rotate[2] = 0; } -// return true; return {translation: translate, rotation: rotate, scale: scale, @@ -1087,6 +1082,15 @@ var MathUtilsClass = exports.MathUtilsClass = Object.create(Object.prototype, { } }, +/** +* Helper function required for matrix decomposition +* A Javascript implementation of pseudo code available from http://www.w3.org/TR/css3-2d-transforms/#matrix-decomposition +* @param {Vector4} aPoint A 3D point +* @param {float} ascl +* @param {float} bscl +* @author Joe Lambert +* @returns {Vector4} +*/ combine: { value: function(a, b, ascl, bscl) { -- cgit v1.2.3