Inlined DihedralAngle and ensured Real-ops used for increased performance.

modules/geom/src/vecmat3_op.cc

@@ -178,20 +178,6 @@ Mat3 AxisRotation(const Vec3& axis, Real angle)
           xy-ca*xy+sa*z, yy+ca-ca*yy, yz-ca*yz-sa*x,
           xz-ca*xz-sa*y, yz-ca*yz+sa*x,zz+ca-ca*zz);
 }
-
-
-Real DihedralAngle(const Vec3& p1, const Vec3& p2, const Vec3& p3, 
-                   const Vec3&p4)
-{
-  Vec3 r1=p2-p1;
-  Vec3 r2=p3-p2;
-  Vec3 r3=p4-p3;
-  Vec3 r12cross = Cross(r1, r2);
-  Vec3 r23cross = Cross(r2, r3);
-  return atan2(Dot(r1*Length(r2), r23cross),
-               Dot(r12cross, r23cross));
-}
-
   
 Real MinDistance(const Vec3List& l1, const Vec3List& l2)
 { 

modules/geom/src/vecmat3_op.hh

@@ -166,9 +166,16 @@ Mat3 DLLEXPORT_OST_GEOM AxisRotation(const Vec3& axis, Real angle);
 /// The returned vector is of length 1
 Vec3 DLLEXPORT_OST_GEOM OrthogonalVector(const Vec3& axis);
 
-
-Real DLLEXPORT_OST_GEOM DihedralAngle(const Vec3& p1, const Vec3& p2, 
-                                      const Vec3& p3, const Vec3&p4);
+/// \brief Get dihedral angle for p1-p2-p3-p4
+inline Real DihedralAngle(const Vec3& p1, const Vec3& p2,
+                          const Vec3& p3, const Vec3& p4) {
+  const Vec3 r1 = p2-p1;
+  const Vec3 r2 = p3-p2;
+  const Vec3 r3 = p4-p3;
+  const Vec3 r12cross = Cross(r1, r2);
+  const Vec3 r23cross = Cross(r2, r3);
+  return std::atan2(Dot(r1*Length(r2), r23cross), Dot(r12cross, r23cross));
+}
 
 //! returns std::min of each component
 inline Vec3 Min(const Vec3& v1, const Vec3& v2)