#ifndef SGVec4_H
#define SGVec4_H
-#ifndef NO_OPENSCENEGRAPH_INTERFACE
-#include <osg/Vec4f>
-#include <osg/Vec4d>
-#endif
+#include <iosfwd>
/// 4D Vector Class
template<typename T>
{ data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; data()[3] = d[3]; }
explicit SGVec4(const SGVec3<T>& v3, const T& v4 = 0)
{ data()[0] = v3[0]; data()[1] = v3[1]; data()[2] = v3[2]; data()[3] = v4; }
-#ifndef NO_OPENSCENEGRAPH_INTERFACE
- explicit SGVec4(const osg::Vec4f& d)
- { data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; data()[3] = d[3]; }
- explicit SGVec4(const osg::Vec4d& d)
- { data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; data()[3] = d[3]; }
-#endif
/// Access by index, the index is unchecked
const T& operator()(unsigned i) const
T (&data(void))[4]
{ return _data; }
-#ifndef NO_OPENSCENEGRAPH_INTERFACE
- osg::Vec4d osg() const
- { return osg::Vec4d(data()[0], data()[1], data()[2], data()[3]); }
-#endif
-
/// Inplace addition
SGVec4& operator+=(const SGVec4& v)
{ data()[0]+=v(0);data()[1]+=v(1);data()[2]+=v(2);data()[3]+=v(3);return *this; }
inline
SGVec4<T>
normalize(const SGVec4<T>& v)
-{ return (1/norm(v))*v; }
+{
+ T normv = norm(v);
+ if (normv <= SGLimits<T>::min())
+ return SGVec4<T>::zeros();
+ return (1/normv)*v;
+}
/// Return true if exactly the same
template<typename T>
distSqr(const SGVec4<T>& v1, const SGVec4<T>& v2)
{ SGVec4<T> tmp = v1 - v2; return dot(tmp, tmp); }
+// calculate the projection of u along the direction of d.
+template<typename T>
+inline
+SGVec4<T>
+projection(const SGVec4<T>& u, const SGVec4<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
toVec4d(const SGVec4f& v)
{ return SGVec4d(v(0), v(1), v(2), v(3)); }
-#ifndef NO_OPENSCENEGRAPH_INTERFACE
-inline
-SGVec4d
-toSG(const osg::Vec4d& v)
-{ return SGVec4d(v[0], v[1], v[2], v[3]); }
-
-inline
-SGVec4f
-toSG(const osg::Vec4f& v)
-{ return SGVec4f(v[0], v[1], v[2], v[3]); }
-
-inline
-osg::Vec4d
-toOsg(const SGVec4d& v)
-{ return osg::Vec4d(v[0], v[1], v[2], v[3]); }
-
-inline
-osg::Vec4f
-toOsg(const SGVec4f& v)
-{ return osg::Vec4f(v[0], v[1], v[2], v[3]); }
-#endif
-
#endif