X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fmath%2FSGVec2.hxx;h=2a40564145c39e68ad13426a4b556f92a0ad6506;hb=7a52c2fa71355631a559d74e0860fa6c5efa424e;hp=f910499133f8fdd24e02c8055dda186867e0fc98;hpb=006f90997a8eef6704de2511e38fcc786672308d;p=simgear.git

diff --git a/simgear/math/SGVec2.hxx b/simgear/math/SGVec2.hxx
index f9104991..2a405641 100644
--- a/simgear/math/SGVec2.hxx
+++ b/simgear/math/SGVec2.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
@@ -18,62 +18,14 @@
 #ifndef SGVec2_H
 #define SGVec2_H
 
-#if defined ( __CYGWIN__ )
-#include <ieeefp.h>
-#endif
-
+#ifndef NO_OPENSCENEGRAPH_INTERFACE
 #include <osg/Vec2f>
 #include <osg/Vec2d>
-
-template<typename T>
-struct SGVec2Storage {
-  /// Readonly raw storage interface
-  const T (&data(void) const)[2]
-  { return _data; }
-  /// Readonly raw storage interface
-  T (&data(void))[2]
-  { return _data; }
-
-  void osg() const
-  { }
-
-private:
-  T _data[2];
-};
-
-template<>
-struct SGVec2Storage<float> : public osg::Vec2f {
-  /// Access raw data by index, the index is unchecked
-  const float (&data(void) const)[2]
-  { return osg::Vec2f::_v; }
-  /// Access raw data by index, the index is unchecked
-  float (&data(void))[2]
-  { return osg::Vec2f::_v; }
-
-  const osg::Vec2f& osg() const
-  { return *this; }
-  osg::Vec2f& osg()
-  { return *this; }
-};
-
-template<>
-struct SGVec2Storage<double> : public osg::Vec2d {
-  /// Access raw data by index, the index is unchecked
-  const double (&data(void) const)[2]
-  { return osg::Vec2d::_v; }
-  /// Access raw data by index, the index is unchecked
-  double (&data(void))[2]
-  { return osg::Vec2d::_v; }
-
-  const osg::Vec2d& osg() const
-  { return *this; }
-  osg::Vec2d& osg()
-  { return *this; }
-};
+#endif
 
 /// 2D Vector Class
 template<typename T>
-class SGVec2 : protected SGVec2Storage<T> {
+class SGVec2 {
 public:
   typedef T value_type;
 
@@ -99,10 +51,6 @@ public:
   template<typename S>
   explicit SGVec2(const SGVec2<S>& d)
   { data()[0] = d[0]; data()[1] = d[1]; }
-  explicit SGVec2(const osg::Vec2f& d)
-  { data()[0] = d[0]; data()[1] = d[1]; }
-  explicit SGVec2(const osg::Vec2d& d)
-  { data()[0] = d[0]; data()[1] = d[1]; }
 
   /// Access by index, the index is unchecked
   const T& operator()(unsigned i) const
@@ -131,18 +79,12 @@ public:
   T& y(void)
   { return data()[1]; }
 
-  /// Get the data pointer
-  using SGVec2Storage<T>::data;
-
-  /// Readonly interface function to ssg's sgVec2/sgdVec2
-  const T (&sg(void) const)[2]
-  { return data(); }
-  /// Interface function to ssg's sgVec2/sgdVec2
-  T (&sg(void))[2]
-  { return data(); }
-
-  /// Interface function to osg's Vec2*
-  using SGVec2Storage<T>::osg;
+  /// Access raw data
+  const T (&data(void) const)[2]
+  { return _data; }
+  /// Access raw data
+  T (&data(void))[2]
+  { return _data; }
 
   /// Inplace addition
   SGVec2& operator+=(const SGVec2& v)
@@ -167,6 +109,9 @@ public:
   { return SGVec2(1, 0); }
   static SGVec2 e2(void)
   { return SGVec2(0, 1); }
+
+private:
+  T _data[2];
 };
 
 /// Unary +, do nothing ...
@@ -295,7 +240,12 @@ template<typename T>
 inline
 SGVec2<T>
 normalize(const SGVec2<T>& v)
-{ return (1/norm(v))*v; }
+{
+  T normv = norm(v);
+  if (normv <= SGLimits<T>::min())
+    return SGVec2<T>::zeros();
+  return (1/normv)*v;
+}
 
 /// Return true if exactly the same
 template<typename T>
@@ -382,6 +332,18 @@ T
 distSqr(const SGVec2<T>& v1, const SGVec2<T>& v2)
 { SGVec2<T> tmp = v1 - v2; return dot(tmp, tmp); }
 
+// calculate the projection of u along the direction of d.
+template<typename T>
+inline
+SGVec2<T>
+projection(const SGVec2<T>& u, const SGVec2<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
@@ -409,4 +371,27 @@ SGVec2d
 toVec2d(const SGVec2f& v)
 { return SGVec2d(v(0), v(1)); }
 
+#ifndef NO_OPENSCENEGRAPH_INTERFACE
+inline
+SGVec2d
+toSG(const osg::Vec2d& v)
+{ return SGVec2d(v[0], v[1]); }
+
+inline
+SGVec2f
+toSG(const osg::Vec2f& v)
+{ return SGVec2f(v[0], v[1]); }
+
+inline
+osg::Vec2d
+toOsg(const SGVec2d& v)
+{ return osg::Vec2d(v[0], v[1]); }
+
+inline
+osg::Vec2f
+toOsg(const SGVec2f& v)
+{ return osg::Vec2f(v[0], v[1]); }
+
+#endif
+
 #endif