X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fmath%2FSGVec3.hxx;h=64ceac0a88ac141ed6273738c624779745b2573f;hb=7a52c2fa71355631a559d74e0860fa6c5efa424e;hp=4ec4145a399f005a05ab88d85d1271f2cb919488;hpb=006f90997a8eef6704de2511e38fcc786672308d;p=simgear.git

diff --git a/simgear/math/SGVec3.hxx b/simgear/math/SGVec3.hxx
index 4ec4145a..64ceac0a 100644
--- a/simgear/math/SGVec3.hxx
+++ b/simgear/math/SGVec3.hxx
@@ -1,4 +1,4 @@
-// Copyright (C) 2006  Mathias Froehlich - Mathias.Froehlich@web.de
+// Copyright (C) 2006-2009  Mathias Froehlich - Mathias.Froehlich@web.de
 //
 // This library is free software; you can redistribute it and/or
 // modify it under the terms of the GNU Library General Public
@@ -18,58 +18,14 @@
 #ifndef SGVec3_H
 #define SGVec3_H
 
+#ifndef NO_OPENSCENEGRAPH_INTERFACE
 #include <osg/Vec3f>
 #include <osg/Vec3d>
-
-template<typename T>
-struct SGVec3Storage {
-  /// Readonly raw storage interface
-  const T (&data(void) const)[3]
-  { return _data; }
-  /// Readonly raw storage interface
-  T (&data(void))[3]
-  { return _data; }
-
-  void osg() const
-  { }
-
-private:
-  T _data[3];
-};
-
-template<>
-struct SGVec3Storage<float> : public osg::Vec3f {
-  /// Access raw data by index, the index is unchecked
-  const float (&data(void) const)[3]
-  { return osg::Vec3f::_v; }
-  /// Access raw data by index, the index is unchecked
-  float (&data(void))[3]
-  { return osg::Vec3f::_v; }
-
-  const osg::Vec3f& osg() const
-  { return *this; }
-  osg::Vec3f& osg()
-  { return *this; }
-};
-
-template<>
-struct SGVec3Storage<double> : public osg::Vec3d {
-  /// Access raw data by index, the index is unchecked
-  const double (&data(void) const)[3]
-  { return osg::Vec3d::_v; }
-  /// Access raw data by index, the index is unchecked
-  double (&data(void))[3]
-  { return osg::Vec3d::_v; }
-
-  const osg::Vec3d& osg() const
-  { return *this; }
-  osg::Vec3d& osg()
-  { return *this; }
-};
+#endif
 
 /// 3D Vector Class
 template<typename T>
-class SGVec3 : protected SGVec3Storage<T> {
+class SGVec3 {
 public:
   typedef T value_type;
 
@@ -95,10 +51,6 @@ public:
   template<typename S>
   explicit SGVec3(const SGVec3<S>& d)
   { data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; }
-  explicit SGVec3(const osg::Vec3f& d)
-  { data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; }
-  explicit SGVec3(const osg::Vec3d& d)
-  { data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; }
   explicit SGVec3(const SGVec2<T>& v2, const T& v3 = 0)
   { data()[0] = v2[0]; data()[1] = v2[1]; data()[2] = v3; }
 
@@ -135,18 +87,12 @@ public:
   T& z(void)
   { return data()[2]; }
 
-  /// Get the data pointer
-  using SGVec3Storage<T>::data;
-
-  /// Readonly interface function to ssg's sgVec3/sgdVec3
-  const T (&sg(void) const)[3]
-  { return data(); }
-  /// Interface function to ssg's sgVec3/sgdVec3
-  T (&sg(void))[3]
-  { return data(); }
-
-  /// Interface function to osg's Vec3*
-  using SGVec3Storage<T>::osg;
+  /// Readonly raw storage interface
+  const T (&data(void) const)[3]
+  { return _data; }
+  /// Readonly raw storage interface
+  T (&data(void))[3]
+  { return _data; }
 
   /// Inplace addition
   SGVec3& operator+=(const SGVec3& v)
@@ -180,6 +126,9 @@ public:
   /// Constructor. Initialize by a geocentric coordinate
   /// Note that this conversion is relatively expensive to compute
   static SGVec3 fromGeoc(const SGGeoc& geoc);
+
+private:
+  T _data[3];
 };
 
 template<>
@@ -403,12 +352,18 @@ perpendicular(const SGVec3<T>& v)
   }
 }
 
-/// The euclidean norm of the vector, that is what most people call length
+/// Construct a unit vector in the given direction.
+/// or the zero vector if the input vector is zero.
 template<typename T>
 inline
 SGVec3<T>
 normalize(const SGVec3<T>& v)
-{ return (1/norm(v))*v; }
+{
+  T normv = norm(v);
+  if (normv <= SGLimits<T>::min())
+    return SGVec3<T>::zeros();
+  return (1/normv)*v;
+}
 
 /// Return true if exactly the same
 template<typename T>
@@ -499,6 +454,18 @@ T
 distSqr(const SGVec3<T>& v1, const SGVec3<T>& v2)
 { SGVec3<T> tmp = v1 - v2; return dot(tmp, tmp); }
 
+// calculate the projection of u along the direction of d.
+template<typename T>
+inline
+SGVec3<T>
+projection(const SGVec3<T>& u, const SGVec3<T>& d)
+{
+  T denom = dot(d, d);
+  T ud = dot(u, d);
+  if (SGLimits<T>::min() < denom) return u;
+  else return d * (dot(u, d) / denom);
+}
+
 #ifndef NDEBUG
 template<typename T>
 inline
@@ -527,4 +494,26 @@ SGVec3d
 toVec3d(const SGVec3f& v)
 { return SGVec3d(v(0), v(1), v(2)); }
 
+#ifndef NO_OPENSCENEGRAPH_INTERFACE
+inline
+SGVec3d
+toSG(const osg::Vec3d& v)
+{ return SGVec3d(v[0], v[1], v[2]); }
+
+inline
+SGVec3f
+toSG(const osg::Vec3f& v)
+{ return SGVec3f(v[0], v[1], v[2]); }
+
+inline
+osg::Vec3d
+toOsg(const SGVec3d& v)
+{ return osg::Vec3d(v[0], v[1], v[2]); }
+
+inline
+osg::Vec3f
+toOsg(const SGVec3f& v)
+{ return osg::Vec3f(v[0], v[1], v[2]); }
+#endif
+
 #endif