comparison: src/basics.cpp
src/basics.cpp
- changeset 1390
- 3eace926af7f
- parent 1389
- 3fb8ad4d27b1
- child 1418
- 503d4e7e27c9
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| 1389:3fb8ad4d27b1 | 1390:3eace926af7f |
|---|---|
| 190 bool wasBlockingSignals = object->signalsBlocked(); | 190 bool wasBlockingSignals = object->signalsBlocked(); |
| 191 object->blockSignals(true); | 191 object->blockSignals(true); |
| 192 function(); | 192 function(); |
| 193 object->blockSignals(wasBlockingSignals); | 193 object->blockSignals(wasBlockingSignals); |
| 194 } | 194 } |
| 195 | |
| 196 /* | |
| 197 * Returns the angle between two vectors | |
| 198 */ | |
| 199 qreal vectorAngle(const QVector3D& vec_1, const QVector3D& vec_2) | |
| 200 { | |
| 201 return acos(QVector3D::dotProduct(vec_1, vec_2) / vec_1.length() / vec_2.length()); | |
| 202 } | |
| 203 | |
| 204 /* | |
| 205 * Computes the determinant of a 2×2 matrix with each variable passed in row-major order. | |
| 206 */ | |
| 207 qreal determinant(qreal a, qreal b, qreal c, qreal d) | |
| 208 { | |
| 209 return a * d - b * c; | |
| 210 } | |
| 211 | |
| 212 /* | |
| 213 * Computes the determinant of a 3×3 matrix with each variable passed in row-major order. | |
| 214 */ | |
| 215 qreal determinant(qreal a, qreal b, qreal c, qreal d, qreal e, qreal f, qreal g, qreal h, qreal i) | |
| 216 { | |
| 217 return a*e*i + b*f*g + c*d*h - a*f*h - b*d*i - c*e*g; | |
| 218 } | |
| 219 | |
| 220 /* | |
| 221 * Computes the determinant of a 2×2 matrix. | |
| 222 */ | |
| 223 qreal determinant(const QMatrix2x2& matrix) | |
| 224 { | |
| 225 return matrix(0, 0) * matrix(1, 1) - matrix(0, 1) * matrix(1, 0); | |
| 226 } | |
| 227 | |
| 228 /* | |
| 229 * Computes the determinant of a 3×3 matrix. | |
| 230 */ | |
| 231 qreal determinant(const QMatrix3x3& matrix) | |
| 232 { | |
| 233 return sum( | |
| 234 +matrix(0, 0) * matrix(1, 1) * matrix(2, 2), | |
| 235 -matrix(0, 0) * matrix(1, 2) * matrix(2, 1), | |
| 236 -matrix(0, 1) * matrix(1, 0) * matrix(2, 2), | |
| 237 +matrix(0, 1) * matrix(1, 2) * matrix(2, 0), | |
| 238 +matrix(0, 2) * matrix(1, 0) * matrix(2, 1), | |
| 239 -matrix(0, 2) * matrix(1, 1) * matrix(2, 0)); | |
| 240 } | |
| 241 | |
| 242 /* | |
| 243 * Computes the determinant of a 4×4 matrix. | |
| 244 */ | |
| 245 qreal determinant(const QMatrix4x4& matrix) | |
| 246 { | |
| 247 qreal sum = 0; | |
| 248 | |
| 249 for (int column : {0, 1, 2, 3}) | |
| 250 { | |
| 251 int column_1 = (column >= 1) ? 0 : 1; | |
| 252 int column_2 = (column >= 2) ? 1 : 2; | |
| 253 int column_3 = (column >= 3) ? 2 : 3; | |
| 254 sum += ((column % 1) ? -1 : 1) * determinant( | |
| 255 matrix(1, column_1), matrix(1, column_2), matrix(1, column_3), | |
| 256 matrix(2, column_1), matrix(2, column_2), matrix(2, column_3), | |
| 257 matrix(3, column_1), matrix(3, column_2), matrix(3, column_3)); | |
| 258 } | |
| 259 | |
| 260 return sum; | |
| 261 } |
