| 1 | greg | 1.1 | #ifndef lint | 
| 2 | greg | 1.3 | static const char       RCSid[] = "$Id$"; | 
| 3 | greg | 1.1 | #endif | 
| 4 |  |  | #include <math.h> | 
| 5 |  |  | #include <string.h> | 
| 6 |  |  | #include "vect.h" | 
| 7 |  |  |  | 
| 8 |  |  | #ifndef M_PI | 
| 9 |  |  | #define M_PI    3.14159265358979323846 | 
| 10 |  |  | #endif | 
| 11 | gregl | 1.2 | #define PI      ((double)M_PI) | 
| 12 | greg | 1.1 |  | 
| 13 |  |  | #define EPSILON 1e-6 | 
| 14 |  |  |  | 
| 15 |  |  | void   adjoint (Matrix mat); | 
| 16 |  |  | double det4x4 (Matrix mat); | 
| 17 |  |  | double det3x3 (double a1, double a2, double a3, double b1, double b2, | 
| 18 |  |  | double b3, double c1, double c2, double c3); | 
| 19 |  |  | double det2x2 (double a, double b, double c, double d); | 
| 20 |  |  |  | 
| 21 |  |  |  | 
| 22 |  |  | void vect_init (Vector v, float  x, float  y, float  z) | 
| 23 |  |  | { | 
| 24 |  |  | v[X] = x; | 
| 25 |  |  | v[Y] = y; | 
| 26 |  |  | v[Z] = z; | 
| 27 |  |  | } | 
| 28 |  |  |  | 
| 29 |  |  |  | 
| 30 |  |  | void vect_copy (Vector v1, Vector v2) | 
| 31 |  |  | { | 
| 32 |  |  | v1[X] = v2[X]; | 
| 33 |  |  | v1[Y] = v2[Y]; | 
| 34 |  |  | v1[Z] = v2[Z]; | 
| 35 |  |  | } | 
| 36 |  |  |  | 
| 37 |  |  |  | 
| 38 |  |  | int vect_equal (Vector v1, Vector v2) | 
| 39 |  |  | { | 
| 40 |  |  | if (v1[X] == v2[X] && v1[Y] == v2[Y] && v1[Z] == v2[Z]) | 
| 41 |  |  | return 1; | 
| 42 |  |  | else | 
| 43 |  |  | return 0; | 
| 44 |  |  | } | 
| 45 |  |  |  | 
| 46 |  |  |  | 
| 47 |  |  | void vect_add (Vector v1, Vector v2, Vector v3) | 
| 48 |  |  | { | 
| 49 |  |  | v1[X] = v2[X] + v3[X]; | 
| 50 |  |  | v1[Y] = v2[Y] + v3[Y]; | 
| 51 |  |  | v1[Z] = v2[Z] + v3[Z]; | 
| 52 |  |  | } | 
| 53 |  |  |  | 
| 54 |  |  |  | 
| 55 |  |  | void vect_sub (Vector v1, Vector v2, Vector v3) | 
| 56 |  |  | { | 
| 57 |  |  | v1[X] = v2[X] - v3[X]; | 
| 58 |  |  | v1[Y] = v2[Y] - v3[Y]; | 
| 59 |  |  | v1[Z] = v2[Z] - v3[Z]; | 
| 60 |  |  | } | 
| 61 |  |  |  | 
| 62 |  |  |  | 
| 63 |  |  | void vect_scale (Vector v1, Vector v2, float  k) | 
| 64 |  |  | { | 
| 65 |  |  | v1[X] = k * v2[X]; | 
| 66 |  |  | v1[Y] = k * v2[Y]; | 
| 67 |  |  | v1[Z] = k * v2[Z]; | 
| 68 |  |  | } | 
| 69 |  |  |  | 
| 70 |  |  |  | 
| 71 |  |  | float vect_mag (Vector v) | 
| 72 |  |  | { | 
| 73 |  |  | float mag = sqrt(v[X]*v[X] + v[Y]*v[Y] + v[Z]*v[Z]); | 
| 74 |  |  |  | 
| 75 |  |  | return mag; | 
| 76 |  |  | } | 
| 77 |  |  |  | 
| 78 |  |  |  | 
| 79 |  |  | void vect_normalize (Vector v) | 
| 80 |  |  | { | 
| 81 |  |  | float mag = vect_mag (v); | 
| 82 |  |  |  | 
| 83 |  |  | if (mag > 0.0) | 
| 84 |  |  | vect_scale (v, v, 1.0/mag); | 
| 85 |  |  | } | 
| 86 |  |  |  | 
| 87 |  |  |  | 
| 88 |  |  | float vect_dot (Vector v1, Vector v2) | 
| 89 |  |  | { | 
| 90 |  |  | return (v1[X]*v2[X] + v1[Y]*v2[Y] + v1[Z]*v2[Z]); | 
| 91 |  |  | } | 
| 92 |  |  |  | 
| 93 |  |  |  | 
| 94 |  |  | void vect_cross (Vector v1, Vector v2, Vector v3) | 
| 95 |  |  | { | 
| 96 |  |  | v1[X] = (v2[Y] * v3[Z]) - (v2[Z] * v3[Y]); | 
| 97 |  |  | v1[Y] = (v2[Z] * v3[X]) - (v2[X] * v3[Z]); | 
| 98 |  |  | v1[Z] = (v2[X] * v3[Y]) - (v2[Y] * v3[X]); | 
| 99 |  |  | } | 
| 100 |  |  |  | 
| 101 |  |  | void vect_min (Vector v1, Vector v2, Vector v3) | 
| 102 |  |  | { | 
| 103 |  |  | v1[X] = (v2[X] < v3[X]) ? v2[X] : v3[X]; | 
| 104 |  |  | v1[Y] = (v2[Y] < v3[Y]) ? v2[Y] : v3[Y]; | 
| 105 |  |  | v1[Z] = (v2[Z] < v3[Z]) ? v2[Z] : v3[Z]; | 
| 106 |  |  | } | 
| 107 |  |  |  | 
| 108 |  |  |  | 
| 109 |  |  | void vect_max (Vector v1, Vector v2, Vector v3) | 
| 110 |  |  | { | 
| 111 |  |  | v1[X] = (v2[X] > v3[X]) ? v2[X] : v3[X]; | 
| 112 |  |  | v1[Y] = (v2[Y] > v3[Y]) ? v2[Y] : v3[Y]; | 
| 113 |  |  | v1[Z] = (v2[Z] > v3[Z]) ? v2[Z] : v3[Z]; | 
| 114 |  |  | } | 
| 115 |  |  |  | 
| 116 |  |  |  | 
| 117 |  |  | /* Return the angle between two vectors */ | 
| 118 |  |  | float vect_angle (Vector v1, Vector v2) | 
| 119 |  |  | { | 
| 120 |  |  | float  mag1, mag2, angle, cos_theta; | 
| 121 |  |  |  | 
| 122 |  |  | mag1 = vect_mag(v1); | 
| 123 |  |  | mag2 = vect_mag(v2); | 
| 124 |  |  |  | 
| 125 |  |  | if (mag1 * mag2 == 0.0) | 
| 126 |  |  | angle = 0.0; | 
| 127 |  |  | else { | 
| 128 |  |  | cos_theta = vect_dot(v1,v2) / (mag1 * mag2); | 
| 129 |  |  |  | 
| 130 |  |  | if (cos_theta <= -1.0) | 
| 131 |  |  | angle = 180.0; | 
| 132 |  |  | else if (cos_theta >= +1.0) | 
| 133 |  |  | angle = 0.0; | 
| 134 |  |  | else | 
| 135 | gregl | 1.2 | angle = (180.0/PI) * acos(cos_theta); | 
| 136 | greg | 1.1 | } | 
| 137 |  |  |  | 
| 138 |  |  | return angle; | 
| 139 |  |  | } | 
| 140 |  |  |  | 
| 141 |  |  |  | 
| 142 |  |  | void vect_print (FILE *f, Vector v, int dec, char sep) | 
| 143 |  |  | { | 
| 144 |  |  | char fstr[] = "%.4f, %.4f, %.4f"; | 
| 145 |  |  |  | 
| 146 |  |  | if (dec < 0) dec = 0; | 
| 147 |  |  | if (dec > 9) dec = 9; | 
| 148 |  |  |  | 
| 149 |  |  | fstr[2]  = '0' + dec; | 
| 150 |  |  | fstr[8]  = '0' + dec; | 
| 151 |  |  | fstr[14] = '0' + dec; | 
| 152 |  |  |  | 
| 153 |  |  | fstr[4]  = sep; | 
| 154 |  |  | fstr[10] = sep; | 
| 155 |  |  |  | 
| 156 |  |  | fprintf (f, fstr, v[X], v[Y], v[Z]); | 
| 157 |  |  | } | 
| 158 |  |  |  | 
| 159 |  |  |  | 
| 160 |  |  | /* Rotate a vector about the X, Y or Z axis */ | 
| 161 |  |  | void vect_rotate (Vector v1, Vector v2, int axis, float angle) | 
| 162 |  |  | { | 
| 163 |  |  | float  cosa, sina; | 
| 164 |  |  |  | 
| 165 | gregl | 1.2 | cosa = cos ((PI/180.0) * angle); | 
| 166 |  |  | sina = sin ((PI/180.0) * angle); | 
| 167 | greg | 1.1 |  | 
| 168 |  |  | switch (axis) { | 
| 169 |  |  | case X: | 
| 170 |  |  | v1[X] =  v2[X]; | 
| 171 |  |  | v1[Y] =  v2[Y] * cosa + v2[Z] * sina; | 
| 172 |  |  | v1[Z] =  v2[Z] * cosa - v2[Y] * sina; | 
| 173 |  |  | break; | 
| 174 |  |  |  | 
| 175 |  |  | case Y: | 
| 176 |  |  | v1[X] = v2[X] * cosa - v2[Z] * sina; | 
| 177 |  |  | v1[Y] = v2[Y]; | 
| 178 |  |  | v1[Z] = v2[Z] * cosa + v2[X] * sina; | 
| 179 |  |  | break; | 
| 180 |  |  |  | 
| 181 |  |  | case Z: | 
| 182 |  |  | v1[X] = v2[X] * cosa + v2[Y] * sina; | 
| 183 |  |  | v1[Y] = v2[Y] * cosa - v2[X] * sina; | 
| 184 |  |  | v1[Z] = v2[Z]; | 
| 185 |  |  | break; | 
| 186 |  |  | } | 
| 187 |  |  | } | 
| 188 |  |  |  | 
| 189 |  |  |  | 
| 190 |  |  | /* Rotate a vector about a specific axis */ | 
| 191 |  |  | void vect_axis_rotate (Vector v1, Vector v2, Vector axis, float angle) | 
| 192 |  |  | { | 
| 193 |  |  | float  cosa, sina; | 
| 194 |  |  | Matrix mat; | 
| 195 |  |  |  | 
| 196 | gregl | 1.2 | cosa = cos ((PI/180.0) * angle); | 
| 197 |  |  | sina = sin ((PI/180.0) * angle); | 
| 198 | greg | 1.1 |  | 
| 199 |  |  | mat[0][0] = (axis[X] * axis[X]) + ((1.0 - (axis[X] * axis[X]))*cosa); | 
| 200 |  |  | mat[0][1] = (axis[X] * axis[Y] * (1.0 - cosa)) - (axis[Z] * sina); | 
| 201 |  |  | mat[0][2] = (axis[X] * axis[Z] * (1.0 - cosa)) + (axis[Y] * sina); | 
| 202 |  |  | mat[0][3] = 0.0; | 
| 203 |  |  |  | 
| 204 |  |  | mat[1][0] = (axis[X] * axis[Y] * (1.0 - cosa)) + (axis[Z] * sina); | 
| 205 |  |  | mat[1][1] = (axis[Y] * axis[Y]) + ((1.0 - (axis[Y] * axis[Y])) * cosa); | 
| 206 |  |  | mat[1][2] = (axis[Y] * axis[Z] * (1.0 - cosa)) - (axis[X] * sina); | 
| 207 |  |  | mat[1][3] = 0.0; | 
| 208 |  |  |  | 
| 209 |  |  | mat[2][0] = (axis[X] * axis[Z] * (1.0 - cosa)) - (axis[Y] * sina); | 
| 210 |  |  | mat[2][1] = (axis[Y] * axis[Z] * (1.0 - cosa)) + (axis[X] * sina); | 
| 211 |  |  | mat[2][2] = (axis[Z] * axis[Z]) + ((1.0 - (axis[Z] * axis[Z])) * cosa); | 
| 212 |  |  | mat[2][3] = 0.0; | 
| 213 |  |  |  | 
| 214 |  |  | mat[3][0] = mat[3][1] = mat[3][2] = mat[3][3] = 0.0; | 
| 215 |  |  |  | 
| 216 |  |  | vect_transform (v1, v2, mat); | 
| 217 |  |  | } | 
| 218 |  |  |  | 
| 219 |  |  |  | 
| 220 |  |  | /* Transform the given vector */ | 
| 221 |  |  | void vect_transform (Vector v1, Vector v2, Matrix mat) | 
| 222 |  |  | { | 
| 223 |  |  | Vector tmp; | 
| 224 |  |  |  | 
| 225 |  |  | tmp[X] = (v2[X] * mat[0][0]) + (v2[Y] * mat[1][0]) + (v2[Z] * mat[2][0]) + mat[3][0]; | 
| 226 |  |  | tmp[Y] = (v2[X] * mat[0][1]) + (v2[Y] * mat[1][1]) + (v2[Z] * mat[2][1]) + mat[3][1]; | 
| 227 |  |  | tmp[Z] = (v2[X] * mat[0][2]) + (v2[Y] * mat[1][2]) + (v2[Z] * mat[2][2]) + mat[3][2]; | 
| 228 |  |  |  | 
| 229 |  |  | vect_copy (v1, tmp); | 
| 230 |  |  | } | 
| 231 |  |  |  | 
| 232 |  |  |  | 
| 233 |  |  | /* Create an identity matrix */ | 
| 234 |  |  | void mat_identity (Matrix mat) | 
| 235 |  |  | { | 
| 236 |  |  | int i, j; | 
| 237 |  |  |  | 
| 238 |  |  | for (i = 0; i < 4; i++) | 
| 239 |  |  | for (j = 0; j < 4; j++) | 
| 240 |  |  | mat[i][j] = 0.0; | 
| 241 |  |  |  | 
| 242 |  |  | for (i = 0; i < 4; i++) | 
| 243 |  |  | mat[i][i] = 1.0; | 
| 244 |  |  | } | 
| 245 |  |  |  | 
| 246 |  |  |  | 
| 247 |  |  | void mat_copy (Matrix mat1, Matrix mat2) | 
| 248 |  |  | { | 
| 249 |  |  | int i, j; | 
| 250 |  |  |  | 
| 251 |  |  | for (i = 0; i < 4; i++) | 
| 252 |  |  | for (j = 0; j < 4; j++) | 
| 253 |  |  | mat1[i][j] = mat2[i][j]; | 
| 254 |  |  | } | 
| 255 |  |  |  | 
| 256 |  |  |  | 
| 257 |  |  | /* Rotate a matrix about the X, Y or Z axis */ | 
| 258 |  |  | void mat_rotate (Matrix mat1, Matrix mat2, int axis, float angle) | 
| 259 |  |  | { | 
| 260 |  |  | Matrix mat; | 
| 261 |  |  | float  cosa, sina; | 
| 262 |  |  |  | 
| 263 | gregl | 1.2 | cosa = cos ((PI/180.0) * angle); | 
| 264 |  |  | sina = sin ((PI/180.0) * angle); | 
| 265 | greg | 1.1 |  | 
| 266 |  |  | mat_identity (mat); | 
| 267 |  |  |  | 
| 268 |  |  | switch (axis) { | 
| 269 |  |  | case X: | 
| 270 |  |  | mat[1][1] = cosa; | 
| 271 |  |  | mat[1][2] = sina; | 
| 272 |  |  | mat[2][1] = -sina; | 
| 273 |  |  | mat[2][2] = cosa; | 
| 274 |  |  | break; | 
| 275 |  |  |  | 
| 276 |  |  | case Y: | 
| 277 |  |  | mat[0][0] = cosa; | 
| 278 |  |  | mat[0][2] = -sina; | 
| 279 |  |  | mat[2][0] = sina; | 
| 280 |  |  | mat[2][2] = cosa; | 
| 281 |  |  | break; | 
| 282 |  |  |  | 
| 283 |  |  | case Z: | 
| 284 |  |  | mat[0][0] = cosa; | 
| 285 |  |  | mat[0][1] = sina; | 
| 286 |  |  | mat[1][0] = -sina; | 
| 287 |  |  | mat[1][1] = cosa; | 
| 288 |  |  | break; | 
| 289 |  |  | } | 
| 290 |  |  |  | 
| 291 |  |  | mat_mult (mat1, mat2, mat); | 
| 292 |  |  | } | 
| 293 |  |  |  | 
| 294 |  |  |  | 
| 295 |  |  | void mat_axis_rotate (Matrix mat1, Matrix mat2, Vector axis, float angle) | 
| 296 |  |  | { | 
| 297 |  |  | float  cosa, sina; | 
| 298 |  |  | Matrix mat; | 
| 299 |  |  |  | 
| 300 | gregl | 1.2 | cosa = cos ((PI/180.0) * angle); | 
| 301 |  |  | sina = sin ((PI/180.0) * angle); | 
| 302 | greg | 1.1 |  | 
| 303 |  |  | mat[0][0] = (axis[X] * axis[X]) + ((1.0 - (axis[X] * axis[X]))*cosa); | 
| 304 |  |  | mat[0][1] = (axis[X] * axis[Y] * (1.0 - cosa)) - (axis[Z] * sina); | 
| 305 |  |  | mat[0][2] = (axis[X] * axis[Z] * (1.0 - cosa)) + (axis[Y] * sina); | 
| 306 |  |  | mat[0][3] = 0.0; | 
| 307 |  |  |  | 
| 308 |  |  | mat[1][0] = (axis[X] * axis[Y] * (1.0 - cosa)) + (axis[Z] * sina); | 
| 309 |  |  | mat[1][1] = (axis[Y] * axis[Y]) + ((1.0 - (axis[Y] * axis[Y])) * cosa); | 
| 310 |  |  | mat[1][2] = (axis[Y] * axis[Z] * (1.0 - cosa)) - (axis[X] * sina); | 
| 311 |  |  | mat[1][3] = 0.0; | 
| 312 |  |  |  | 
| 313 |  |  | mat[2][0] = (axis[X] * axis[Z] * (1.0 - cosa)) - (axis[Y] * sina); | 
| 314 |  |  | mat[2][1] = (axis[Y] * axis[Z] * (1.0 - cosa)) + (axis[X] * sina); | 
| 315 |  |  | mat[2][2] = (axis[Z] * axis[Z]) + ((1.0 - (axis[Z] * axis[Z])) * cosa); | 
| 316 |  |  | mat[2][3] = 0.0; | 
| 317 |  |  |  | 
| 318 |  |  | mat[3][0] = mat[3][1] = mat[3][2] = mat[3][3] = 0.0; | 
| 319 |  |  |  | 
| 320 |  |  | mat_mult (mat1, mat2, mat); | 
| 321 |  |  | } | 
| 322 |  |  |  | 
| 323 |  |  |  | 
| 324 |  |  | /*  mat1 <-- mat2 * mat3 */ | 
| 325 |  |  | void mat_mult (Matrix mat1, Matrix mat2, Matrix mat3) | 
| 326 |  |  | { | 
| 327 |  |  | float sum; | 
| 328 |  |  | int   i, j, k; | 
| 329 |  |  | Matrix result; | 
| 330 |  |  |  | 
| 331 |  |  | for (i = 0; i < 4; i++) { | 
| 332 |  |  | for (j = 0; j < 4; j++) { | 
| 333 |  |  | sum = 0.0; | 
| 334 |  |  |  | 
| 335 |  |  | for (k = 0; k < 4; k++) | 
| 336 |  |  | sum = sum + mat2[i][k] * mat3[k][j]; | 
| 337 |  |  |  | 
| 338 |  |  | result[i][j] = sum; | 
| 339 |  |  | } | 
| 340 |  |  | } | 
| 341 |  |  |  | 
| 342 |  |  | for (i = 0; i < 4; i++) | 
| 343 |  |  | for (j = 0; j < 4; j++) | 
| 344 |  |  | mat1[i][j] = result[i][j]; | 
| 345 |  |  | } | 
| 346 |  |  |  | 
| 347 |  |  |  | 
| 348 |  |  | /* | 
| 349 |  |  | Decodes a 3x4 transformation matrix into separate scale, rotation, | 
| 350 |  |  | translation, and shear vectors. Based on a program by Spencer W. | 
| 351 |  |  | Thomas (Graphics Gems II) | 
| 352 |  |  | */ | 
| 353 |  |  | void mat_decode (Matrix mat, Vector scale,  Vector shear, Vector rotate, | 
| 354 |  |  | Vector transl) | 
| 355 |  |  | { | 
| 356 |  |  | int i; | 
| 357 |  |  | Vector row[3], temp; | 
| 358 |  |  |  | 
| 359 |  |  | for (i = 0; i < 3; i++) | 
| 360 |  |  | transl[i] = mat[3][i]; | 
| 361 |  |  |  | 
| 362 |  |  | for (i = 0; i < 3; i++) { | 
| 363 |  |  | row[i][X] = mat[i][0]; | 
| 364 |  |  | row[i][Y] = mat[i][1]; | 
| 365 |  |  | row[i][Z] = mat[i][2]; | 
| 366 |  |  | } | 
| 367 |  |  |  | 
| 368 |  |  | scale[X] = vect_mag (row[0]); | 
| 369 |  |  | vect_normalize (row[0]); | 
| 370 |  |  |  | 
| 371 |  |  | shear[X] = vect_dot (row[0], row[1]); | 
| 372 |  |  | row[1][X] = row[1][X] - shear[X]*row[0][X]; | 
| 373 |  |  | row[1][Y] = row[1][Y] - shear[X]*row[0][Y]; | 
| 374 |  |  | row[1][Z] = row[1][Z] - shear[X]*row[0][Z]; | 
| 375 |  |  |  | 
| 376 |  |  | scale[Y] = vect_mag (row[1]); | 
| 377 |  |  | vect_normalize (row[1]); | 
| 378 |  |  |  | 
| 379 |  |  | if (scale[Y] != 0.0) | 
| 380 |  |  | shear[X] /= scale[Y]; | 
| 381 |  |  |  | 
| 382 |  |  | shear[Y] = vect_dot (row[0], row[2]); | 
| 383 |  |  | row[2][X] = row[2][X] - shear[Y]*row[0][X]; | 
| 384 |  |  | row[2][Y] = row[2][Y] - shear[Y]*row[0][Y]; | 
| 385 |  |  | row[2][Z] = row[2][Z] - shear[Y]*row[0][Z]; | 
| 386 |  |  |  | 
| 387 |  |  | shear[Z] = vect_dot (row[1], row[2]); | 
| 388 |  |  | row[2][X] = row[2][X] - shear[Z]*row[1][X]; | 
| 389 |  |  | row[2][Y] = row[2][Y] - shear[Z]*row[1][Y]; | 
| 390 |  |  | row[2][Z] = row[2][Z] - shear[Z]*row[1][Z]; | 
| 391 |  |  |  | 
| 392 |  |  | scale[Z] = vect_mag (row[2]); | 
| 393 |  |  | vect_normalize (row[2]); | 
| 394 |  |  |  | 
| 395 |  |  | if (scale[Z] != 0.0) { | 
| 396 |  |  | shear[Y] /= scale[Z]; | 
| 397 |  |  | shear[Z] /= scale[Z]; | 
| 398 |  |  | } | 
| 399 |  |  |  | 
| 400 |  |  | vect_cross (temp, row[1], row[2]); | 
| 401 |  |  | if (vect_dot (row[0], temp) < 0.0) { | 
| 402 |  |  | for (i = 0; i < 3; i++) { | 
| 403 |  |  | scale[i]  *= -1.0; | 
| 404 |  |  | row[i][X] *= -1.0; | 
| 405 |  |  | row[i][Y] *= -1.0; | 
| 406 |  |  | row[i][Z] *= -1.0; | 
| 407 |  |  | } | 
| 408 |  |  | } | 
| 409 |  |  |  | 
| 410 |  |  | if (row[0][Z] < -1.0) row[0][Z] = -1.0; | 
| 411 |  |  | if (row[0][Z] > +1.0) row[0][Z] = +1.0; | 
| 412 |  |  |  | 
| 413 |  |  | rotate[Y] = asin(-row[0][Z]); | 
| 414 |  |  |  | 
| 415 |  |  | if (fabs(cos(rotate[Y])) > EPSILON) { | 
| 416 |  |  | rotate[X] = atan2 (row[1][Z], row[2][Z]); | 
| 417 |  |  | rotate[Z] = atan2 (row[0][Y], row[0][X]); | 
| 418 |  |  | } | 
| 419 |  |  | else { | 
| 420 |  |  | rotate[X] = atan2 (row[1][X], row[1][Y]); | 
| 421 |  |  | rotate[Z] = 0.0; | 
| 422 |  |  | } | 
| 423 |  |  |  | 
| 424 |  |  | /* Convert the rotations to degrees */ | 
| 425 | gregl | 1.2 | rotate[X] = (180.0/PI)*rotate[X]; | 
| 426 |  |  | rotate[Y] = (180.0/PI)*rotate[Y]; | 
| 427 |  |  | rotate[Z] = (180.0/PI)*rotate[Z]; | 
| 428 | greg | 1.1 | } | 
| 429 |  |  |  | 
| 430 |  |  |  | 
| 431 |  |  | /* Matrix inversion code from Graphics Gems */ | 
| 432 |  |  |  | 
| 433 |  |  | /* mat1 <-- mat2^-1 */ | 
| 434 |  |  | float mat_inv (Matrix mat1, Matrix mat2) | 
| 435 |  |  | { | 
| 436 |  |  | int i, j; | 
| 437 |  |  | float det; | 
| 438 |  |  |  | 
| 439 |  |  | if (mat1 != mat2) { | 
| 440 |  |  | for (i = 0; i < 4; i++) | 
| 441 |  |  | for (j = 0; j < 4; j++) | 
| 442 |  |  | mat1[i][j] = mat2[i][j]; | 
| 443 |  |  | } | 
| 444 |  |  |  | 
| 445 |  |  | det = det4x4 (mat1); | 
| 446 |  |  |  | 
| 447 |  |  | if (fabs (det) < EPSILON) | 
| 448 |  |  | return 0.0; | 
| 449 |  |  |  | 
| 450 |  |  | adjoint (mat1); | 
| 451 |  |  |  | 
| 452 |  |  | for (i = 0; i < 4; i++) | 
| 453 |  |  | for(j = 0; j < 4; j++) | 
| 454 |  |  | mat1[i][j] = mat1[i][j] / det; | 
| 455 |  |  |  | 
| 456 |  |  | return det; | 
| 457 |  |  | } | 
| 458 |  |  |  | 
| 459 |  |  |  | 
| 460 |  |  | void adjoint (Matrix mat) | 
| 461 |  |  | { | 
| 462 |  |  | double a1, a2, a3, a4, b1, b2, b3, b4; | 
| 463 |  |  | double c1, c2, c3, c4, d1, d2, d3, d4; | 
| 464 |  |  |  | 
| 465 |  |  | a1 = mat[0][0]; b1 = mat[0][1]; | 
| 466 |  |  | c1 = mat[0][2]; d1 = mat[0][3]; | 
| 467 |  |  |  | 
| 468 |  |  | a2 = mat[1][0]; b2 = mat[1][1]; | 
| 469 |  |  | c2 = mat[1][2]; d2 = mat[1][3]; | 
| 470 |  |  |  | 
| 471 |  |  | a3 = mat[2][0]; b3 = mat[2][1]; | 
| 472 |  |  | c3 = mat[2][2]; d3 = mat[2][3]; | 
| 473 |  |  |  | 
| 474 |  |  | a4 = mat[3][0]; b4 = mat[3][1]; | 
| 475 |  |  | c4 = mat[3][2]; d4 = mat[3][3]; | 
| 476 |  |  |  | 
| 477 |  |  | /* row column labeling reversed since we transpose rows & columns */ | 
| 478 |  |  | mat[0][0]  =  det3x3 (b2, b3, b4, c2, c3, c4, d2, d3, d4); | 
| 479 |  |  | mat[1][0]  = -det3x3 (a2, a3, a4, c2, c3, c4, d2, d3, d4); | 
| 480 |  |  | mat[2][0]  =  det3x3 (a2, a3, a4, b2, b3, b4, d2, d3, d4); | 
| 481 |  |  | mat[3][0]  = -det3x3 (a2, a3, a4, b2, b3, b4, c2, c3, c4); | 
| 482 |  |  |  | 
| 483 |  |  | mat[0][1]  = -det3x3 (b1, b3, b4, c1, c3, c4, d1, d3, d4); | 
| 484 |  |  | mat[1][1]  =  det3x3 (a1, a3, a4, c1, c3, c4, d1, d3, d4); | 
| 485 |  |  | mat[2][1]  = -det3x3 (a1, a3, a4, b1, b3, b4, d1, d3, d4); | 
| 486 |  |  | mat[3][1]  =  det3x3 (a1, a3, a4, b1, b3, b4, c1, c3, c4); | 
| 487 |  |  |  | 
| 488 |  |  | mat[0][2]  =  det3x3 (b1, b2, b4, c1, c2, c4, d1, d2, d4); | 
| 489 |  |  | mat[1][2]  = -det3x3 (a1, a2, a4, c1, c2, c4, d1, d2, d4); | 
| 490 |  |  | mat[2][2]  =  det3x3 (a1, a2, a4, b1, b2, b4, d1, d2, d4); | 
| 491 |  |  | mat[3][2]  = -det3x3 (a1, a2, a4, b1, b2, b4, c1, c2, c4); | 
| 492 |  |  |  | 
| 493 |  |  | mat[0][3]  = -det3x3 (b1, b2, b3, c1, c2, c3, d1, d2, d3); | 
| 494 |  |  | mat[1][3]  =  det3x3 (a1, a2, a3, c1, c2, c3, d1, d2, d3); | 
| 495 |  |  | mat[2][3]  = -det3x3 (a1, a2, a3, b1, b2, b3, d1, d2, d3); | 
| 496 |  |  | mat[3][3]  =  det3x3 (a1, a2, a3, b1, b2, b3, c1, c2, c3); | 
| 497 |  |  | } | 
| 498 |  |  |  | 
| 499 |  |  |  | 
| 500 |  |  | double det4x4 (Matrix mat) | 
| 501 |  |  | { | 
| 502 |  |  | double ans; | 
| 503 |  |  | double a1, a2, a3, a4, b1, b2, b3, b4, c1, c2, c3, c4, d1, d2, d3,                  d4; | 
| 504 |  |  |  | 
| 505 |  |  | a1 = mat[0][0]; b1 = mat[0][1]; | 
| 506 |  |  | c1 = mat[0][2]; d1 = mat[0][3]; | 
| 507 |  |  |  | 
| 508 |  |  | a2 = mat[1][0]; b2 = mat[1][1]; | 
| 509 |  |  | c2 = mat[1][2]; d2 = mat[1][3]; | 
| 510 |  |  |  | 
| 511 |  |  | a3 = mat[2][0]; b3 = mat[2][1]; | 
| 512 |  |  | c3 = mat[2][2]; d3 = mat[2][3]; | 
| 513 |  |  |  | 
| 514 |  |  | a4 = mat[3][0]; b4 = mat[3][1]; | 
| 515 |  |  | c4 = mat[3][2]; d4 = mat[3][3]; | 
| 516 |  |  |  | 
| 517 |  |  | ans = a1 * det3x3 (b2, b3, b4, c2, c3, c4, d2, d3, d4) - | 
| 518 |  |  | b1 * det3x3 (a2, a3, a4, c2, c3, c4, d2, d3, d4) + | 
| 519 |  |  | c1 * det3x3 (a2, a3, a4, b2, b3, b4, d2, d3, d4) - | 
| 520 |  |  | d1 * det3x3 (a2, a3, a4, b2, b3, b4, c2, c3, c4); | 
| 521 |  |  |  | 
| 522 |  |  | return ans; | 
| 523 |  |  | } | 
| 524 |  |  |  | 
| 525 |  |  |  | 
| 526 |  |  | double det3x3 (double a1, double a2, double a3, double b1, double b2, | 
| 527 |  |  | double b3, double c1, double c2, double c3) | 
| 528 |  |  | { | 
| 529 |  |  | double ans; | 
| 530 |  |  |  | 
| 531 |  |  | ans = a1 * det2x2 (b2, b3, c2, c3) | 
| 532 |  |  | - b1 * det2x2 (a2, a3, c2, c3) | 
| 533 |  |  | + c1 * det2x2 (a2, a3, b2, b3); | 
| 534 |  |  |  | 
| 535 |  |  | return ans; | 
| 536 |  |  | } | 
| 537 |  |  |  | 
| 538 |  |  |  | 
| 539 |  |  | double det2x2 (double a, double b, double c, double d) | 
| 540 |  |  | { | 
| 541 |  |  | double ans; | 
| 542 |  |  | ans = a * d - b * c; | 
| 543 |  |  | return ans; | 
| 544 |  |  | } | 
| 545 |  |  |  |