X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fmath%2FSGVec4.hxx;h=4339dfd9b79879a3fab0da2b59a5cca747cc5578;hb=584ee1364f25e5c3795f9ff4633a792cba39bfc7;hp=d610a6ca8c11851285edfaa9a3f33f901cbf7a84;hpb=bd3518637cb9477313427745eff4038e0dafedfe;p=simgear.git

diff --git a/simgear/math/SGVec4.hxx b/simgear/math/SGVec4.hxx
index d610a6ca..4339dfd9 100644
--- a/simgear/math/SGVec4.hxx
+++ b/simgear/math/SGVec4.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 +18,11 @@
 #ifndef SGVec4_H
 #define SGVec4_H
 
-#include <osg/Vec4f>
-#include <osg/Vec4d>
-
-template<typename T>
-struct SGVec4Storage {
-  /// Readonly raw storage interface
-  const T (&data(void) const)[4]
-  { return _data; }
-  /// Readonly raw storage interface
-  T (&data(void))[4]
-  { return _data; }
-
-  void osg() const
-  { }
-
-private:
-  T _data[4];
-};
-
-template<>
-struct SGVec4Storage<float> : public osg::Vec4f {
-  /// Access raw data by index, the index is unchecked
-  const float (&data(void) const)[4]
-  { return osg::Vec4f::_v; }
-  /// Access raw data by index, the index is unchecked
-  float (&data(void))[4]
-  { return osg::Vec4f::_v; }
-
-  const osg::Vec4f& osg() const
-  { return *this; }
-  osg::Vec4f& osg()
-  { return *this; }
-};
-
-template<>
-struct SGVec4Storage<double> : public osg::Vec4d {
-  /// Access raw data by index, the index is unchecked
-  const double (&data(void) const)[4]
-  { return osg::Vec4d::_v; }
-  /// Access raw data by index, the index is unchecked
-  double (&data(void))[4]
-  { return osg::Vec4d::_v; }
-
-  const osg::Vec4d& osg() const
-  { return *this; }
-  osg::Vec4d& osg()
-  { return *this; }
-};
+#include <iosfwd>
 
 /// 4D Vector Class
 template<typename T>
-class SGVec4 : protected SGVec4Storage<T> {
+class SGVec4 {
 public:
   typedef T value_type;
 
@@ -92,11 +45,11 @@ public:
   /// make sure it has at least 3 elements
   explicit SGVec4(const T* d)
   { data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; data()[3] = d[3]; }
-  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)
+  template<typename S>
+  explicit SGVec4(const SGVec4<S>& d)
   { 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; }
 
   /// Access by index, the index is unchecked
   const T& operator()(unsigned i) const
@@ -137,18 +90,12 @@ public:
   T& w(void)
   { return data()[3]; }
 
-  /// Get the data pointer
-  using SGVec4Storage<T>::data;
-
-  /// Readonly interface function to ssg's sgVec4/sgdVec4
-  const T (&sg(void) const)[4]
-  { return data(); }
-  /// Interface function to ssg's sgVec4/sgdVec4
-  T (&sg(void))[4]
-  { return data(); }
-
-  /// Interface function to osg's Vec4*
-  using SGVec4Storage<T>::osg;
+  /// Readonly raw storage interface
+  const T (&data(void) const)[4]
+  { return _data; }
+  /// Readonly raw storage interface
+  T (&data(void))[4]
+  { return _data; }
 
   /// Inplace addition
   SGVec4& operator+=(const SGVec4& v)
@@ -177,6 +124,9 @@ public:
   { return SGVec4(0, 0, 1, 0); }
   static SGVec4 e4(void)
   { return SGVec4(0, 0, 0, 1); }
+
+private:
+  T _data[4];
 };
 
 /// Unary +, do nothing ...
@@ -221,6 +171,15 @@ SGVec4<T>
 operator*(const SGVec4<T>& v, S s)
 { return SGVec4<T>(s*v(0), s*v(1), s*v(2), s*v(3)); }
 
+/// multiplication as a multiplicator, that is assume that the first vector
+/// represents a 4x4 diagonal matrix with the diagonal elements in the vector.
+/// Then the result is the product of that matrix times the second vector.
+template<typename T>
+inline
+SGVec4<T>
+mult(const SGVec4<T>& v1, const SGVec4<T>& v2)
+{ return SGVec4<T>(v1(0)*v2(0), v1(1)*v2(1), v1(2)*v2(2), v1(3)*v2(3)); }
+
 /// component wise min
 template<typename T>
 inline
@@ -285,6 +244,19 @@ max(S s, const SGVec4<T>& v)
                    SGMisc<T>::max(s, v(3)));
 }
 
+/// Add two vectors taking care of (integer) overflows. The values are limited
+/// to the respective minimum and maximum values.
+template<class T>
+SGVec4<T> addClipOverflow(SGVec4<T> const& lhs, SGVec4<T> const& rhs)
+{
+  return SGVec4<T>(
+    SGMisc<T>::addClipOverflow(lhs.x(), rhs.x()),
+    SGMisc<T>::addClipOverflow(lhs.y(), rhs.y()),
+    SGMisc<T>::addClipOverflow(lhs.z(), rhs.z()),
+    SGMisc<T>::addClipOverflow(lhs.w(), rhs.w())
+  );
+}
+
 /// Scalar dot product
 template<typename T>
 inline
@@ -326,7 +298,12 @@ template<typename T>
 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>
@@ -342,6 +319,47 @@ bool
 operator!=(const SGVec4<T>& v1, const SGVec4<T>& v2)
 { return ! (v1 == v2); }
 
+/// Return true if smaller, good for putting that into a std::map
+template<typename T>
+inline
+bool
+operator<(const SGVec4<T>& v1, const SGVec4<T>& v2)
+{
+  if (v1(0) < v2(0)) return true;
+  else if (v2(0) < v1(0)) return false;
+  else if (v1(1) < v2(1)) return true;
+  else if (v2(1) < v1(1)) return false;
+  else if (v1(2) < v2(2)) return true;
+  else if (v2(2) < v1(2)) return false;
+  else return (v1(3) < v2(3));
+}
+
+template<typename T>
+inline
+bool
+operator<=(const SGVec4<T>& v1, const SGVec4<T>& v2)
+{
+  if (v1(0) < v2(0)) return true;
+  else if (v2(0) < v1(0)) return false;
+  else if (v1(1) < v2(1)) return true;
+  else if (v2(1) < v1(1)) return false;
+  else if (v1(2) < v2(2)) return true;
+  else if (v2(2) < v1(2)) return false;
+  else return (v1(3) <= v2(3));
+}
+
+template<typename T>
+inline
+bool
+operator>(const SGVec4<T>& v1, const SGVec4<T>& v2)
+{ return operator<(v2, v1); }
+
+template<typename T>
+inline
+bool
+operator>=(const SGVec4<T>& v1, const SGVec4<T>& v2)
+{ return operator<=(v2, v1); }
+
 /// Return true if equal to the relative tolerance tol
 template<typename T>
 inline
@@ -380,6 +398,18 @@ 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