1 files changed, 64 insertions, 0 deletions
diff --git a/facetracknoir/rotation.h b/facetracknoir/rotation.h
new file mode 100644
index 00000000..22f35abb
--- /dev/null
+++ b/facetracknoir/rotation.h
@@ -0,0 +1,64 @@
+/* Copyright (c) 2012 Patrick Ruoff
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ */
+
+#ifndef ROTATION_H
+#define ROTATION_H
+#include <cmath>
+// ----------------------------------------------------------------------------
+class RotationType {
+
+public:
+	RotationType() : a(1.0),b(0.0),c(0.0),d(0.0) {}
+	RotationType(double yaw, double pitch, double roll) { fromEuler(yaw, pitch, roll); }
+	RotationType(double a, double b, double c, double d) : a(a),b(b),c(c),d(d) {}
+
+	RotationType inv(){	// inverse
+		return RotationType(a,-b,-c, -d);
+	}
+
+
+	// conversions
+	// 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 toEuler(double& yaw, double& pitch, double& roll) const
+    {
+        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 RotationType operator*(const RotationType& B) const
+    {
+        const RotationType& A = *this;
+        return RotationType(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 a,b,c,d; // quaternion coefficients
+};
+
+
+
+#endif //ROTATION_H