math: Add integer valued vector types.

[simgear.git] / simgear / math / SGVec3.hxx

diff --git a/simgear/math/SGVec3.hxx b/simgear/math/SGVec3.hxx
index f2b7406a647083cdc5d4422d81b08cde6ba51312..dbc8af543bf9a5d39a933be30d55e32b9dfc9c43 100644 (file)
--- a/simgear/math/SGVec3.hxx
+++ b/simgear/math/SGVec3.hxx
@@ -18,10 +18,7 @@
 #ifndef SGVec3_H
 #define SGVec3_H
 
-#ifndef NO_OPENSCENEGRAPH_INTERFACE
-#include <osg/Vec3f>
-#include <osg/Vec3d>
-#endif
+#include <iosfwd>
 
 /// 3D Vector Class
 template<typename T>
@@ -29,6 +26,11 @@ class SGVec3 {
 public:
   typedef T value_type;
 
+#ifdef __GNUC__
+// Avoid "_data not initialized" warnings (see comment below).
+#   pragma GCC diagnostic ignored "-Wuninitialized"
+#endif
+
   /// Default constructor. Does not initialize at all.
   /// If you need them zero initialized, use SGVec3::zeros()
   SGVec3(void)
@@ -41,6 +43,12 @@ public:
       data()[i] = SGLimits<T>::quiet_NaN();
 #endif
   }
+
+#ifdef __GNUC__
+  // Restore warning settings.
+#   pragma GCC diagnostic warning "-Wuninitialized"
+#endif
+
   /// Constructor. Initialize by the given values
   SGVec3(T x, T y, T z)
   { data()[0] = x; data()[1] = y; data()[2] = z; }
@@ -53,12 +61,6 @@ public:
   { 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; }
-#ifndef NO_OPENSCENEGRAPH_INTERFACE
-  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]; }
-#endif
 
   /// Access by index, the index is unchecked
   const T& operator()(unsigned i) const
@@ -100,11 +102,6 @@ public:
   T (&data(void))[3]
   { return _data; }
 
-#ifndef NO_OPENSCENEGRAPH_INTERFACE
-  osg::Vec3d osg() const
-  { return osg::Vec3d(data()[0], data()[1], data()[2]); }
-#endif
-
   /// Inplace addition
   SGVec3& operator+=(const SGVec3& v)
   { data()[0] += v(0); data()[1] += v(1); data()[2] += v(2); return *this; }
@@ -363,12 +360,18 @@ 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>
@@ -459,6 +462,18 @@ 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
@@ -487,26 +502,4 @@ 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