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-rw-r--r--facetracknoir/rotation.h49
1 files changed, 24 insertions, 25 deletions
diff --git a/facetracknoir/rotation.h b/facetracknoir/rotation.h
index 1e472cf2..5385b545 100644
--- a/facetracknoir/rotation.h
+++ b/facetracknoir/rotation.h
@@ -12,12 +12,12 @@
class Rotation {
public:
- Rotation() : w(1.0),x(0.0),y(0.0),z(0.0) {}
+ Rotation() : a(1.0),b(0.0),c(0.0),d(0.0) {}
Rotation(double yaw, double pitch, double roll) { fromEuler(yaw, pitch, roll); }
- Rotation(double x, double y, double z, double w) : x(x),y(y),z(z),w(w) {}
+ Rotation(double a, double b, double c, double d) : a(a),b(b),c(c),d(d) {}
Rotation inv(){ // inverse
- return Rotation(-x,-y,-z, w);
+ return Rotation(a,-b,-c, -d);
}
@@ -25,26 +25,25 @@ public:
// see http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles
void fromEuler(double yaw, double pitch, double roll)
{
- // Assuming the angles are in radians.
- double c1 = cos(yaw);
- double s1 = sin(yaw);
- double c2 = cos(roll);
- double s2 = sin(roll);
- double c3 = cos(pitch);
- double s3 = sin(pitch);
- w = sqrt(1.0 + c1 * c2 + c1*c3 - s1 * s2 * s3 + c2*c3) / 2.0;
- double w4 = (4.0 * w);
- x = (c2 * s3 + c1 * s3 + s1 * s2 * c3) / w4 ;
- y = (s1 * c2 + s1 * c3 + c1 * s2 * s3) / w4 ;
- z = (-s1 * s3 + c1 * s2 * c3 +s2) / w4 ;
+
+ 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 toEuler(double& yaw, double& pitch, double& roll)
+ void Rotation::toEuler(double& yaw, double& pitch, double& roll)
{
-
- yaw = atan2(2.0*(y*w - x*z), 1.0 - 2.0*(y*y + z*z));
- roll = asin(2.0*(x*y + z*w));
- pitch = atan2(2.0*(x*w - y*z), 1.0 - 2.0*(x*x + z*z));
+ 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));
}
/* const Rotation operator*(const Rotation& A, const Rotation& B)
@@ -59,14 +58,14 @@ public:
const Rotation operator*(const Rotation& B)
{
const Rotation& A = *this;
- return Rotation(A.w*B.w - A.x*B.x - A.y*B.y - A.z*B.z, // quaternion multiplication
- A.w*B.x + A.x*B.w + A.y*B.z - A.z*B.y,
- A.w*B.y - A.x*B.z + A.y*B.w + A.z*B.x,
- A.w*B.z + A.x*B.y - A.y*B.x + A.z*B.w);
+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);
}
protected:
- double w,x,y,z; // quaternion coefficients
+ double a,b,c,d; // quaternion coefficients
};