diff options
Diffstat (limited to 'facetracknoir/rotation.h')
| -rw-r--r-- | facetracknoir/rotation.h | 42 |
1 files changed, 36 insertions, 6 deletions
diff --git a/facetracknoir/rotation.h b/facetracknoir/rotation.h index 9dcea285..1a4e705b 100644 --- a/facetracknoir/rotation.h +++ b/facetracknoir/rotation.h @@ -7,7 +7,7 @@ #ifndef ROTATION_H
#define ROTATION_H
-
+#include <cmath>
// ----------------------------------------------------------------------------
class Rotation {
friend Rotation operator*(const Rotation& A, const Rotation& B);
@@ -16,16 +16,46 @@ public: Rotation(double yaw, double pitch, double roll) { fromEuler(yaw, pitch, roll); }
Rotation(double a, double b, double c, double d) : a(a),b(b),c(c),d(d) {}
- Rotation inv(); // inverse
+ Rotation inv(){ // inverse
+ return Rotation(a,-b,-c,-d);
+ }
+
// conversions
- void fromEuler(double yaw, double pitch, double roll);
- void toEuler(volatile double& yaw, volatile double& pitch, volatile double& roll);
-
+ // see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles
+ void fromEuler(double yaw, double pitch, double roll)
+ {
+ double sin_phi = sin(roll/2.0);
+ double cos_phi = cos(roll/2.0);
+ double sin_the = sin(pitch/2.0);
+ double cos_the = cos(pitch/2.0);
+ double sin_psi = sin(yaw/2.0);
+ double cos_psi = cos(yaw/2.0);
+
+ a = cos_phi*cos_the*cos_psi + sin_phi*sin_the*sin_psi;
+ b = sin_phi*cos_the*cos_psi - cos_phi*sin_the*sin_psi;
+ c = cos_phi*sin_the*cos_psi + sin_phi*cos_the*sin_psi;
+ d = cos_phi*cos_the*sin_psi - sin_phi*sin_the*cos_psi;
+ }
+
+ void Rotation::toEuler(double& yaw, double& pitch, double& roll)
+ {
+ roll = atan2(2.0*(a*b + c*d), 1.0 - 2.0*(b*b + c*c));
+ pitch = asin(2.0*(a*c - b*d));
+ yaw = atan2(2.0*(a*d + b*c), 1.0 - 2.0*(c*c + d*d));
+ }
+
protected:
double a,b,c,d; // quaternion coefficients
};
-Rotation operator*(const Rotation& A, const Rotation& B); // composition of rotations
+
+Rotation operator*(const Rotation& A, const Rotation& B)
+{
+ return Rotation(A.a*B.a - A.b*B.b - A.c*B.c - A.d*B.d, // quaternion multiplication
+ A.a*B.b + A.b*B.a + A.c*B.d - A.d*B.c,
+ A.a*B.c - A.b*B.d + A.c*B.a + A.d*B.b,
+ A.a*B.d + A.b*B.c - A.c*B.b + A.d*B.a);
+}
#endif //ROTATION_H
|