1/* Copyright (c) 2013, Brandon Jones, Colin MacKenzie IV. All rights reserved. 2 3Redistribution and use in source and binary forms, with or without modification, 4are permitted provided that the following conditions are met: 5 6 * Redistributions of source code must retain the above copyright notice, this 7 list of conditions and the following disclaimer. 8 * Redistributions in binary form must reproduce the above copyright notice, 9 this list of conditions and the following disclaimer in the documentation 10 and/or other materials provided with the distribution. 11 12THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 13ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 14WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 15DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 16ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 17(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 18LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 19ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 20(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 21SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ 22 23/** 24 * @class 2x3 Matrix 25 * @name mat2d 26 * 27 * @description 28 * A mat2d contains six elements defined as: 29 * <pre> 30 * [a, b, 31 * c, d, 32 * tx,ty] 33 * </pre> 34 * This is a short form for the 3x3 matrix: 35 * <pre> 36 * [a, b, 0 37 * c, d, 0 38 * tx,ty,1] 39 * </pre> 40 * The last column is ignored so the array is shorter and operations are faster. 41 */ 42var mat2d = {}; 43 44/** 45 * Creates a new identity mat2d 46 * 47 * @returns {mat2d} a new 2x3 matrix 48 */ 49mat2d.create = function() { 50 var out = new GLMAT_ARRAY_TYPE(6); 51 out[0] = 1; 52 out[1] = 0; 53 out[2] = 0; 54 out[3] = 1; 55 out[4] = 0; 56 out[5] = 0; 57 return out; 58}; 59 60/** 61 * Creates a new mat2d initialized with values from an existing matrix 62 * 63 * @param {mat2d} a matrix to clone 64 * @returns {mat2d} a new 2x3 matrix 65 */ 66mat2d.clone = function(a) { 67 var out = new GLMAT_ARRAY_TYPE(6); 68 out[0] = a[0]; 69 out[1] = a[1]; 70 out[2] = a[2]; 71 out[3] = a[3]; 72 out[4] = a[4]; 73 out[5] = a[5]; 74 return out; 75}; 76 77/** 78 * Copy the values from one mat2d to another 79 * 80 * @param {mat2d} out the receiving matrix 81 * @param {mat2d} a the source matrix 82 * @returns {mat2d} out 83 */ 84mat2d.copy = function(out, a) { 85 out[0] = a[0]; 86 out[1] = a[1]; 87 out[2] = a[2]; 88 out[3] = a[3]; 89 out[4] = a[4]; 90 out[5] = a[5]; 91 return out; 92}; 93 94/** 95 * Set a mat2d to the identity matrix 96 * 97 * @param {mat2d} out the receiving matrix 98 * @returns {mat2d} out 99 */ 100mat2d.identity = function(out) { 101 out[0] = 1; 102 out[1] = 0; 103 out[2] = 0; 104 out[3] = 1; 105 out[4] = 0; 106 out[5] = 0; 107 return out; 108}; 109 110/** 111 * Inverts a mat2d 112 * 113 * @param {mat2d} out the receiving matrix 114 * @param {mat2d} a the source matrix 115 * @returns {mat2d} out 116 */ 117mat2d.invert = function(out, a) { 118 var aa = a[0], ab = a[1], ac = a[2], ad = a[3], 119 atx = a[4], aty = a[5]; 120 121 var det = aa * ad - ab * ac; 122 if(!det){ 123 return null; 124 } 125 det = 1.0 / det; 126 127 out[0] = ad * det; 128 out[1] = -ab * det; 129 out[2] = -ac * det; 130 out[3] = aa * det; 131 out[4] = (ac * aty - ad * atx) * det; 132 out[5] = (ab * atx - aa * aty) * det; 133 return out; 134}; 135 136/** 137 * Calculates the determinant of a mat2d 138 * 139 * @param {mat2d} a the source matrix 140 * @returns {Number} determinant of a 141 */ 142mat2d.determinant = function (a) { 143 return a[0] * a[3] - a[1] * a[2]; 144}; 145 146/** 147 * Multiplies two mat2d's 148 * 149 * @param {mat2d} out the receiving matrix 150 * @param {mat2d} a the first operand 151 * @param {mat2d} b the second operand 152 * @returns {mat2d} out 153 */ 154mat2d.multiply = function (out, a, b) { 155 var aa = a[0], ab = a[1], ac = a[2], ad = a[3], 156 atx = a[4], aty = a[5], 157 ba = b[0], bb = b[1], bc = b[2], bd = b[3], 158 btx = b[4], bty = b[5]; 159 160 out[0] = aa*ba + ab*bc; 161 out[1] = aa*bb + ab*bd; 162 out[2] = ac*ba + ad*bc; 163 out[3] = ac*bb + ad*bd; 164 out[4] = ba*atx + bc*aty + btx; 165 out[5] = bb*atx + bd*aty + bty; 166 return out; 167}; 168 169/** 170 * Alias for {@link mat2d.multiply} 171 * @function 172 */ 173mat2d.mul = mat2d.multiply; 174 175 176/** 177 * Rotates a mat2d by the given angle 178 * 179 * @param {mat2d} out the receiving matrix 180 * @param {mat2d} a the matrix to rotate 181 * @param {Number} rad the angle to rotate the matrix by 182 * @returns {mat2d} out 183 */ 184mat2d.rotate = function (out, a, rad) { 185 var aa = a[0], 186 ab = a[1], 187 ac = a[2], 188 ad = a[3], 189 atx = a[4], 190 aty = a[5], 191 st = Math.sin(rad), 192 ct = Math.cos(rad); 193 194 out[0] = aa*ct + ab*st; 195 out[1] = -aa*st + ab*ct; 196 out[2] = ac*ct + ad*st; 197 out[3] = -ac*st + ct*ad; 198 out[4] = ct*atx + st*aty; 199 out[5] = ct*aty - st*atx; 200 return out; 201}; 202 203/** 204 * Scales the mat2d by the dimensions in the given vec2 205 * 206 * @param {mat2d} out the receiving matrix 207 * @param {mat2d} a the matrix to translate 208 * @param {mat2d} v the vec2 to scale the matrix by 209 * @returns {mat2d} out 210 **/ 211mat2d.scale = function(out, a, v) { 212 var vx = v[0], vy = v[1]; 213 out[0] = a[0] * vx; 214 out[1] = a[1] * vy; 215 out[2] = a[2] * vx; 216 out[3] = a[3] * vy; 217 out[4] = a[4] * vx; 218 out[5] = a[5] * vy; 219 return out; 220}; 221 222/** 223 * Translates the mat2d by the dimensions in the given vec2 224 * 225 * @param {mat2d} out the receiving matrix 226 * @param {mat2d} a the matrix to translate 227 * @param {mat2d} v the vec2 to translate the matrix by 228 * @returns {mat2d} out 229 **/ 230mat2d.translate = function(out, a, v) { 231 out[0] = a[0]; 232 out[1] = a[1]; 233 out[2] = a[2]; 234 out[3] = a[3]; 235 out[4] = a[4] + v[0]; 236 out[5] = a[5] + v[1]; 237 return out; 238}; 239 240/** 241 * Returns a string representation of a mat2d 242 * 243 * @param {mat2d} a matrix to represent as a string 244 * @returns {String} string representation of the matrix 245 */ 246mat2d.str = function (a) { 247 return 'mat2d(' + a[0] + ', ' + a[1] + ', ' + a[2] + ', ' + 248 a[3] + ', ' + a[4] + ', ' + a[5] + ')'; 249}; 250 251if(typeof(exports) !== 'undefined') { 252 exports.mat2d = mat2d; 253} 254