Open Source Tomb Raider Engine
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Matrix.cpp 15KB

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  1. /*!
  2. * \file src/Matrix.cpp
  3. * \brief 3D Matrix
  4. *
  5. * \author Mongoose
  6. */
  7. #include <stdio.h>
  8. #include <math.h>
  9. #include "Matrix.h"
  10. Matrix::Matrix() {
  11. setIdentity();
  12. }
  13. Matrix::Matrix(matrix_t m) {
  14. setMatrix(m);
  15. }
  16. Matrix::Matrix(Quaternion &q) {
  17. matrix_t m;
  18. q.getMatrix(m);
  19. setMatrix(m);
  20. }
  21. bool Matrix::getInvert(matrix_t out) {
  22. matrix_t m;
  23. #ifdef COLUMN_ORDER
  24. getMatrix(m);
  25. #else
  26. getTransposeMatrix(m);
  27. #endif
  28. /* Mongoose: This code was from a Jeff Lander tutorial which was based
  29. on MESA GL's InvertMatrix */
  30. /* NB. OpenGL Matrices are COLUMN major. */
  31. #define SWAP_ROWS(a, b) { float *_tmp = a; (a)=(b); (b)=_tmp; }
  32. #define MAT(m,r,c) (m)[(c)*4+(r)]
  33. float wtmp[4][8];
  34. float m0, m1, m2, m3, s;
  35. float *r0, *r1, *r2, *r3;
  36. r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];
  37. r0[0] = MAT(m,0,0), r0[1] = MAT(m,0,1),
  38. r0[2] = MAT(m,0,2), r0[3] = MAT(m,0,3),
  39. r0[4] = 1.0f, r0[5] = r0[6] = r0[7] = 0.0f,
  40. r1[0] = MAT(m,1,0), r1[1] = MAT(m,1,1),
  41. r1[2] = MAT(m,1,2), r1[3] = MAT(m,1,3),
  42. r1[5] = 1.0f, r1[4] = r1[6] = r1[7] = 0.0f,
  43. r2[0] = MAT(m,2,0), r2[1] = MAT(m,2,1),
  44. r2[2] = MAT(m,2,2), r2[3] = MAT(m,2,3),
  45. r2[6] = 1.0f, r2[4] = r2[5] = r2[7] = 0.0f,
  46. r3[0] = MAT(m,3,0), r3[1] = MAT(m,3,1),
  47. r3[2] = MAT(m,3,2), r3[3] = MAT(m,3,3),
  48. r3[7] = 1.0f, r3[4] = r3[5] = r3[6] = 0.0f;
  49. /* choose pivot - or die */
  50. if (fabs(r3[0])>fabs(r2[0])) SWAP_ROWS(r3, r2);
  51. if (fabs(r2[0])>fabs(r1[0])) SWAP_ROWS(r2, r1);
  52. if (fabs(r1[0])>fabs(r0[0])) SWAP_ROWS(r1, r0);
  53. if (0.0f == r0[0]) return false;
  54. /* eliminate first variable */
  55. m1 = r1[0]/r0[0]; m2 = r2[0]/r0[0]; m3 = r3[0]/r0[0];
  56. s = r0[1]; r1[1] -= m1 * s; r2[1] -= m2 * s; r3[1] -= m3 * s;
  57. s = r0[2]; r1[2] -= m1 * s; r2[2] -= m2 * s; r3[2] -= m3 * s;
  58. s = r0[3]; r1[3] -= m1 * s; r2[3] -= m2 * s; r3[3] -= m3 * s;
  59. s = r0[4];
  60. if (s != 0.0f) { r1[4] -= m1 * s; r2[4] -= m2 * s; r3[4] -= m3 * s; }
  61. s = r0[5];
  62. if (s != 0.0f) { r1[5] -= m1 * s; r2[5] -= m2 * s; r3[5] -= m3 * s; }
  63. s = r0[6];
  64. if (s != 0.0f) { r1[6] -= m1 * s; r2[6] -= m2 * s; r3[6] -= m3 * s; }
  65. s = r0[7];
  66. if (s != 0.0f) { r1[7] -= m1 * s; r2[7] -= m2 * s; r3[7] -= m3 * s; }
  67. /* choose pivot - or die */
  68. if (fabs(r3[1])>fabs(r2[1])) SWAP_ROWS(r3, r2);
  69. if (fabs(r2[1])>fabs(r1[1])) SWAP_ROWS(r2, r1);
  70. if (0.0f == r1[1]) return false;
  71. /* eliminate second variable */
  72. m2 = r2[1]/r1[1]; m3 = r3[1]/r1[1];
  73. r2[2] -= m2 * r1[2]; r3[2] -= m3 * r1[2];
  74. r2[3] -= m2 * r1[3]; r3[3] -= m3 * r1[3];
  75. s = r1[4]; if (0.0f != s) { r2[4] -= m2 * s; r3[4] -= m3 * s; }
  76. s = r1[5]; if (0.0f != s) { r2[5] -= m2 * s; r3[5] -= m3 * s; }
  77. s = r1[6]; if (0.0f != s) { r2[6] -= m2 * s; r3[6] -= m3 * s; }
  78. s = r1[7]; if (0.0f != s) { r2[7] -= m2 * s; r3[7] -= m3 * s; }
  79. /* choose pivot - or die */
  80. if (fabs(r3[2])>fabs(r2[2])) SWAP_ROWS(r3, r2);
  81. if (0.0f == r2[2]) return false;
  82. /* eliminate third variable */
  83. m3 = r3[2]/r2[2];
  84. r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4],
  85. r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6],
  86. r3[7] -= m3 * r2[7];
  87. /* last check */
  88. if (0.0f == r3[3]) return false;
  89. s = 1.0f/r3[3]; /* now back substitute row 3 */
  90. r3[4] *= s; r3[5] *= s; r3[6] *= s; r3[7] *= s;
  91. m2 = r2[3]; /* now back substitute row 2 */
  92. s = 1.0f/r2[2];
  93. r2[4] = s * (r2[4] - r3[4] * m2), r2[5] = s * (r2[5] - r3[5] * m2),
  94. r2[6] = s * (r2[6] - r3[6] * m2), r2[7] = s * (r2[7] - r3[7] * m2);
  95. m1 = r1[3];
  96. r1[4] -= r3[4] * m1, r1[5] -= r3[5] * m1,
  97. r1[6] -= r3[6] * m1, r1[7] -= r3[7] * m1;
  98. m0 = r0[3];
  99. r0[4] -= r3[4] * m0, r0[5] -= r3[5] * m0,
  100. r0[6] -= r3[6] * m0, r0[7] -= r3[7] * m0;
  101. m1 = r1[2]; /* now back substitute row 1 */
  102. s = 1.0f/r1[1];
  103. r1[4] = s * (r1[4] - r2[4] * m1), r1[5] = s * (r1[5] - r2[5] * m1),
  104. r1[6] = s * (r1[6] - r2[6] * m1), r1[7] = s * (r1[7] - r2[7] * m1);
  105. m0 = r0[2];
  106. r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0,
  107. r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0;
  108. m0 = r0[1]; /* now back substitute row 0 */
  109. s = 1.0f/r0[0];
  110. r0[4] = s * (r0[4] - r1[4] * m0), r0[5] = s * (r0[5] - r1[5] * m0),
  111. r0[6] = s * (r0[6] - r1[6] * m0), r0[7] = s * (r0[7] - r1[7] * m0);
  112. MAT(out,0,0) = r0[4];
  113. MAT(out,0,1) = r0[5], MAT(out,0,2) = r0[6];
  114. MAT(out,0,3) = r0[7], MAT(out,1,0) = r1[4];
  115. MAT(out,1,1) = r1[5], MAT(out,1,2) = r1[6];
  116. MAT(out,1,3) = r1[7], MAT(out,2,0) = r2[4];
  117. MAT(out,2,1) = r2[5], MAT(out,2,2) = r2[6];
  118. MAT(out,2,3) = r2[7], MAT(out,3,0) = r3[4];
  119. MAT(out,3,1) = r3[5], MAT(out,3,2) = r3[6];
  120. MAT(out,3,3) = r3[7];
  121. return true;
  122. #undef MAT
  123. #undef SWAP_ROWS
  124. }
  125. void Matrix::getMatrix(matrix_t mat) {
  126. copy(mMatrix, mat);
  127. }
  128. void Matrix::getTransposeMatrix(matrix_t m) {
  129. m[ 0]= mMatrix[0]; m[ 1]= mMatrix[4]; m[ 2]= mMatrix[ 8]; m[ 3]=mMatrix[12];
  130. m[ 4]= mMatrix[1]; m[ 5]= mMatrix[5]; m[ 6]= mMatrix[ 9]; m[ 7]=mMatrix[13];
  131. m[ 8]= mMatrix[2]; m[ 9]= mMatrix[6]; m[10]= mMatrix[10]; m[11]=mMatrix[14];
  132. m[12]= mMatrix[3]; m[13]= mMatrix[7]; m[14]= mMatrix[11]; m[15]=mMatrix[15];
  133. }
  134. Matrix Matrix::multiply(const Matrix &a, const Matrix &b) {
  135. Matrix c;
  136. multiply(a.mMatrix, b.mMatrix, c.mMatrix);
  137. return c;
  138. }
  139. Matrix Matrix::operator *(const Matrix &a) {
  140. return multiply(a, *this);
  141. }
  142. Vector3d Matrix::operator *(Vector3d v) {
  143. vec_t x = v.mVec[0], y = v.mVec[1], z = v.mVec[2];
  144. #ifdef COLUMN_ORDER
  145. return Vector3d(mMatrix[0]*x + mMatrix[4]*y + mMatrix[ 8]*z + mMatrix[12],
  146. mMatrix[1]*x + mMatrix[5]*y + mMatrix[ 9]*z + mMatrix[13],
  147. mMatrix[2]*x + mMatrix[6]*y + mMatrix[10]*z + mMatrix[14]);
  148. #else
  149. return Vector3d(mMatrix[0]*x + mMatrix[1]*y + mMatrix[ 2]*z + mMatrix[ 3],
  150. mMatrix[4]*x + mMatrix[5]*y + mMatrix[ 6]*z + mMatrix[ 7],
  151. mMatrix[8]*x + mMatrix[9]*y + mMatrix[10]*z + mMatrix[11]);
  152. #endif
  153. }
  154. void Matrix::multiply3v(vec3_t v, vec3_t result) {
  155. vec_t x = v[0], y = v[1], z = v[2];
  156. result[0] = mMatrix[0]*x + mMatrix[1]*y + mMatrix[ 2]*z + mMatrix[ 3];
  157. result[1] = mMatrix[4]*x + mMatrix[5]*y + mMatrix[ 6]*z + mMatrix[ 7];
  158. result[2] = mMatrix[8]*x + mMatrix[9]*y + mMatrix[10]*z + mMatrix[11];
  159. }
  160. void Matrix::multiply4v(vec4_t v, vec4_t result) {
  161. vec_t x = v[0], y = v[1], z = v[2], w = v[3];
  162. result[0] = mMatrix[ 0]*x + mMatrix[ 1]*y + mMatrix[ 2]*z + mMatrix[ 3]*w;
  163. result[1] = mMatrix[ 4]*x + mMatrix[ 5]*y + mMatrix[ 6]*z + mMatrix[ 7]*w;
  164. result[2] = mMatrix[ 8]*x + mMatrix[ 9]*y + mMatrix[10]*z + mMatrix[11]*w;
  165. result[3] = mMatrix[12]*x + mMatrix[13]*y + mMatrix[14]*z + mMatrix[15]*w;
  166. }
  167. void Matrix::print() {
  168. printf("{\n%f %f %f %f\n%f %f %f %f\n%f %f %f %f\n%f %f %f %f\n}\n",
  169. #ifdef COLUMN_ORDER
  170. mMatrix[0], mMatrix[4], mMatrix[ 8], mMatrix[12],
  171. mMatrix[1], mMatrix[5], mMatrix[ 9], mMatrix[13],
  172. mMatrix[2], mMatrix[6], mMatrix[10], mMatrix[14],
  173. mMatrix[3], mMatrix[7], mMatrix[11], mMatrix[15]);
  174. #else
  175. mMatrix[ 0], mMatrix[ 1], mMatrix[ 2], mMatrix[ 3],
  176. mMatrix[ 4], mMatrix[ 5], mMatrix[ 6], mMatrix[ 7],
  177. mMatrix[ 8], mMatrix[ 9], mMatrix[10], mMatrix[11],
  178. mMatrix[12], mMatrix[13], mMatrix[14], mMatrix[15]);
  179. #endif
  180. }
  181. bool Matrix::isIdentity() {
  182. // Hhhmm... floating point using direct comparisons
  183. /*
  184. if (mMatrix[ 0] == 1 && mMatrix[ 1] == 0 && mMatrix[ 2] == 0 &&
  185. mMatrix[ 3] == 0 && mMatrix[ 4] == 0 && mMatrix[ 5] == 1 &&
  186. mMatrix[ 6] == 0 && mMatrix[ 7] == 0 && mMatrix[ 8] == 0 &&
  187. mMatrix[ 9] == 0 && mMatrix[10] == 1 && mMatrix[11] == 0 &&
  188. mMatrix[12] == 0 && mMatrix[13] == 0 && mMatrix[14] == 0 &&
  189. mMatrix[15] == 1)
  190. return true;
  191. */
  192. if (equalEpsilon(mMatrix[ 0], 1.0) && equalEpsilon(mMatrix[ 1], 0.0) && equalEpsilon(mMatrix[ 2], 0.0) &&
  193. equalEpsilon(mMatrix[ 3], 0.0) && equalEpsilon(mMatrix[ 4], 0.0) && equalEpsilon(mMatrix[ 5], 1.0) &&
  194. equalEpsilon(mMatrix[ 6], 0.0) && equalEpsilon(mMatrix[ 7], 0.0) && equalEpsilon(mMatrix[ 8], 0.0) &&
  195. equalEpsilon(mMatrix[ 9], 0.0) && equalEpsilon(mMatrix[10], 1.0) && equalEpsilon(mMatrix[11], 0.0) &&
  196. equalEpsilon(mMatrix[12], 0.0) && equalEpsilon(mMatrix[13], 0.0) && equalEpsilon(mMatrix[14], 0.0) &&
  197. equalEpsilon(mMatrix[15], 1.0))
  198. return true;
  199. return false;
  200. }
  201. void Matrix::setMatrix(matrix_t mat) {
  202. copy(mat, mMatrix);
  203. }
  204. void Matrix::setIdentity() {
  205. mMatrix[ 0] = 1; mMatrix[ 1] = 0; mMatrix[ 2] = 0; mMatrix[ 3] = 0;
  206. mMatrix[ 4] = 0; mMatrix[ 5] = 1; mMatrix[ 6] = 0; mMatrix[ 7] = 0;
  207. mMatrix[ 8] = 0; mMatrix[ 9] = 0; mMatrix[10] = 1; mMatrix[11] = 0;
  208. mMatrix[12] = 0; mMatrix[13] = 0; mMatrix[14] = 0; mMatrix[15] = 1;
  209. }
  210. void Matrix::scale(const vec_t *xyz) {
  211. scale(xyz[0], xyz[1], xyz[2]);
  212. }
  213. void Matrix::scale(vec_t sx, vec_t sy, vec_t sz) {
  214. matrix_t smatrix;
  215. matrix_t tmp;
  216. smatrix[ 0] = sx; smatrix[ 1] = 0; smatrix[ 2] = 0; smatrix[ 3] = 0;
  217. smatrix[ 4] = 0; smatrix[ 5] = sy; smatrix[ 6] = 0; smatrix[ 7] = 0;
  218. smatrix[ 8] = 0; smatrix[ 9] = 0; smatrix[10] = sz; smatrix[11] = 0;
  219. smatrix[12] = 0; smatrix[13] = 0; smatrix[14] = 0; smatrix[15] = 1;
  220. copy(mMatrix, tmp);
  221. multiply(tmp, smatrix, mMatrix);
  222. }
  223. void Matrix::rotate(const vec_t *xyz) {
  224. rotate(xyz[0], xyz[1], xyz[2]);
  225. }
  226. void Matrix::rotate(vec_t ax, vec_t ay, vec_t az) {
  227. matrix_t xmat, ymat, zmat, tmp, tmp2;
  228. xmat[ 0]=1; xmat[ 1]=0; xmat[ 2]=0; xmat[ 3]=0;
  229. xmat[ 4]=0; xmat[ 5]=cosf(ax); xmat[ 6]=sinf(ax); xmat[ 7]=0;
  230. xmat[ 8]=0; xmat[ 9]=-sinf(ax); xmat[10]=cosf(ax); xmat[11]=0;
  231. xmat[12]=0; xmat[13]=0; xmat[14]=0; xmat[15]=1;
  232. ymat[ 0]=cosf(ay); ymat[ 1]=0; ymat[ 2]=-sinf(ay); ymat[ 3]=0;
  233. ymat[ 4]=0; ymat[ 5]=1; ymat[ 6]=0; ymat[ 7]=0;
  234. ymat[ 8]=sinf(ay); ymat[ 9]=0; ymat[10]=cosf(ay); ymat[11]=0;
  235. ymat[12]=0; ymat[13]=0; ymat[14]=0; ymat[15]=1;
  236. zmat[ 0]=cosf(az); zmat[ 1]=sinf(az); zmat[ 2]=0; zmat[ 3]=0;
  237. zmat[ 4]=-sinf(az); zmat[ 5]=cosf(az); zmat[ 6]=0; zmat[ 7]=0;
  238. zmat[ 8]=0; zmat[ 9]=0; zmat[10]=1; zmat[11]=0;
  239. zmat[12]=0; zmat[13]=0; zmat[14]=0; zmat[15]=1;
  240. multiply(mMatrix, ymat, tmp);
  241. multiply(tmp, xmat, tmp2);
  242. multiply(tmp2, zmat, mMatrix);
  243. }
  244. void Matrix::translate(const vec_t *xyz) {
  245. translate(xyz[0], xyz[1], xyz[2]);
  246. }
  247. void Matrix::translate(vec_t tx, vec_t ty, vec_t tz) {
  248. matrix_t tmat, tmp;
  249. tmat[ 0]=1; tmat[ 1]=0; tmat[ 2]=0; tmat[ 3]=0;
  250. tmat[ 4]=0; tmat[ 5]=1; tmat[ 6]=0; tmat[ 7]=0;
  251. tmat[ 8]=0; tmat[ 9]=0; tmat[10]=1; tmat[11]=0;
  252. tmat[12]=tx; tmat[13]=ty; tmat[14]=tz; tmat[15]=1;
  253. copy(mMatrix, tmp);
  254. multiply(tmp, tmat, mMatrix);
  255. }
  256. void Matrix::copy(matrix_t source, matrix_t dest) {
  257. for (int i = 0; i < 16; i++)
  258. dest[i] = source[i];
  259. }
  260. void Matrix::multiply(const matrix_t a, const matrix_t b, matrix_t result) {
  261. /* Generated code for matrix mult
  262. * Code used:
  263. // char order is argument
  264. int i, j, k;
  265. if (order == 'r') {
  266. printf("// Row order\n");
  267. } else {
  268. printf("// Column order\n");
  269. }
  270. for (i = 0; i < 4; ++i) {
  271. for (j = 0; j < 4; ++j) {
  272. if (order == 'r') {
  273. printf("result[%2i] = ", j+i*4);
  274. } else {
  275. printf("result[%2i] = ", j+i*4);
  276. }
  277. for (k = 0; k < 4; ++k) {
  278. if (order == 'r') {
  279. printf("a[%2i] * b[%2i]%s",
  280. k+i*4, j+k*4, (k == 3) ? ";\n" : " + ");
  281. } else {
  282. printf("a[%2i] * b[%2i]%s",
  283. i+k*4, k+j*4, (k == 3) ? ";\n" : " + ");
  284. }
  285. //sum+=(elements[i+k*4]*m.elements[k+j*4]);
  286. }
  287. //result.elements[i+j*4]=sum;
  288. }
  289. printf("\n");
  290. }
  291. printf("\n");
  292. printf("// Transpose\n");
  293. for(i = 0; i < 4; ++i) {
  294. for (j = 0; j < 4; ++j) {
  295. printf("a[%2i] = b[%2i]%s",
  296. j+i*4, i+j*4, (j == 3) ? ";\n" : "; ");
  297. }
  298. }
  299. * was in test/Matrix.cpp
  300. */
  301. #ifdef COLUMN_ORDER
  302. /* Column order */
  303. result[ 0] = a[ 0] * b[ 0] + a[ 4] * b[ 1] + a[ 8] * b[ 2] + a[12] * b[ 3];
  304. result[ 1] = a[ 0] * b[ 4] + a[ 4] * b[ 5] + a[ 8] * b[ 6] + a[12] * b[ 7];
  305. result[ 2] = a[ 0] * b[ 8] + a[ 4] * b[ 9] + a[ 8] * b[10] + a[12] * b[11];
  306. result[ 3] = a[ 0] * b[12] + a[ 4] * b[13] + a[ 8] * b[14] + a[12] * b[15];
  307. result[ 4] = a[ 1] * b[ 0] + a[ 5] * b[ 1] + a[ 9] * b[ 2] + a[13] * b[ 3];
  308. result[ 5] = a[ 1] * b[ 4] + a[ 5] * b[ 5] + a[ 9] * b[ 6] + a[13] * b[ 7];
  309. result[ 6] = a[ 1] * b[ 8] + a[ 5] * b[ 9] + a[ 9] * b[10] + a[13] * b[11];
  310. result[ 7] = a[ 1] * b[12] + a[ 5] * b[13] + a[ 9] * b[14] + a[13] * b[15];
  311. result[ 8] = a[ 2] * b[ 0] + a[ 6] * b[ 1] + a[10] * b[ 2] + a[14] * b[ 3];
  312. result[ 9] = a[ 2] * b[ 4] + a[ 6] * b[ 5] + a[10] * b[ 6] + a[14] * b[ 7];
  313. result[10] = a[ 2] * b[ 8] + a[ 6] * b[ 9] + a[10] * b[10] + a[14] * b[11];
  314. result[11] = a[ 2] * b[12] + a[ 6] * b[13] + a[10] * b[14] + a[14] * b[15];
  315. result[12] = a[ 3] * b[ 0] + a[ 7] * b[ 1] + a[11] * b[ 2] + a[15] * b[ 3];
  316. result[13] = a[ 3] * b[ 4] + a[ 7] * b[ 5] + a[11] * b[ 6] + a[15] * b[ 7];
  317. result[14] = a[ 3] * b[ 8] + a[ 7] * b[ 9] + a[11] * b[10] + a[15] * b[11];
  318. result[15] = a[ 3] * b[12] + a[ 7] * b[13] + a[11] * b[14] + a[15] * b[15];
  319. #else
  320. /* Row order */
  321. result[ 0] = a[ 0] * b[ 0] + a[ 1] * b[ 4] + a[ 2] * b[ 8] + a[ 3] * b[12];
  322. result[ 1] = a[ 0] * b[ 1] + a[ 1] * b[ 5] + a[ 2] * b[ 9] + a[ 3] * b[13];
  323. result[ 2] = a[ 0] * b[ 2] + a[ 1] * b[ 6] + a[ 2] * b[10] + a[ 3] * b[14];
  324. result[ 3] = a[ 0] * b[ 3] + a[ 1] * b[ 7] + a[ 2] * b[11] + a[ 3] * b[15];
  325. result[ 4] = a[ 4] * b[ 0] + a[ 5] * b[ 4] + a[ 6] * b[ 8] + a[ 7] * b[12];
  326. result[ 5] = a[ 4] * b[ 1] + a[ 5] * b[ 5] + a[ 6] * b[ 9] + a[ 7] * b[13];
  327. result[ 6] = a[ 4] * b[ 2] + a[ 5] * b[ 6] + a[ 6] * b[10] + a[ 7] * b[14];
  328. result[ 7] = a[ 4] * b[ 3] + a[ 5] * b[ 7] + a[ 6] * b[11] + a[ 7] * b[15];
  329. result[ 8] = a[ 8] * b[ 0] + a[ 9] * b[ 4] + a[10] * b[ 8] + a[11] * b[12];
  330. result[ 9] = a[ 8] * b[ 1] + a[ 9] * b[ 5] + a[10] * b[ 9] + a[11] * b[13];
  331. result[10] = a[ 8] * b[ 2] + a[ 9] * b[ 6] + a[10] * b[10] + a[11] * b[14];
  332. result[11] = a[ 8] * b[ 3] + a[ 9] * b[ 7] + a[10] * b[11] + a[11] * b[15];
  333. result[12] = a[12] * b[ 0] + a[13] * b[ 4] + a[14] * b[ 8] + a[15] * b[12];
  334. result[13] = a[12] * b[ 1] + a[13] * b[ 5] + a[14] * b[ 9] + a[15] * b[13];
  335. result[14] = a[12] * b[ 2] + a[13] * b[ 6] + a[14] * b[10] + a[15] * b[14];
  336. result[15] = a[12] * b[ 3] + a[13] * b[ 7] + a[14] * b[11] + a[15] * b[15];
  337. #endif
  338. }