X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fmath%2FSGVec3.hxx;h=4ec4145a399f005a05ab88d85d1271f2cb919488;hb=006f90997a8eef6704de2511e38fcc786672308d;hp=d9d998dfd4de0e158db233f0199e48314e805f9f;hpb=67d837c4ec71e21c9d52914344b4dafb7fc06b45;p=simgear.git

diff --git a/simgear/math/SGVec3.hxx b/simgear/math/SGVec3.hxx
index d9d998df..4ec4145a 100644
--- a/simgear/math/SGVec3.hxx
+++ b/simgear/math/SGVec3.hxx
@@ -92,10 +92,15 @@ public:
   /// make sure it has at least 3 elements
   explicit SGVec3(const T* d)
   { data()[0] = d[0]; data()[1] = d[1]; data()[2] = d[2]; }
+  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; }
 
   /// Access by index, the index is unchecked
   const T& operator()(unsigned i) const
@@ -259,6 +264,15 @@ SGVec3<T>
 operator*(const SGVec3<T>& v, S s)
 { return SGVec3<T>(s*v(0), s*v(1), s*v(2)); }
 
+/// multiplication as a multiplicator, that is assume that the first vector
+/// represents a 3x3 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
+SGVec3<T>
+mult(const SGVec3<T>& v1, const SGVec3<T>& v2)
+{ return SGVec3<T>(v1(0)*v2(0), v1(1)*v2(1), v1(2)*v2(2)); }
+
 /// component wise min
 template<typename T>
 inline
@@ -364,18 +378,29 @@ cross(const SGVec3<T>& v1, const SGVec3<T>& v2)
                    v1(0)*v2(1) - v1(1)*v2(0));
 }
 
-/// return any vector perpandicular to v
+/// return any normalized vector perpendicular to v
 template<typename T>
 inline
 SGVec3<T>
-perpandicular(const SGVec3<T>& v)
+perpendicular(const SGVec3<T>& v)
 {
-  if (fabs(v.x()) < fabs(v.y()) && fabs(v.x()) < fabs(v.z()))
-    return cross(SGVec3f(1, 0, 0), v);
-  else if (fabs(v.y()) < fabs(v.x()) && fabs(v.y()) < fabs(v.z()))
-    return cross(SGVec3f(0, 1, 0), v);
-  else
-    return cross(SGVec3f(0, 0, 1), v);
+  T absv1 = fabs(v(0));
+  T absv2 = fabs(v(1));
+  T absv3 = fabs(v(2));
+
+  if (absv2 < absv1 && absv3 < absv1) {
+    T quot = v(1)/v(0);
+    return (1/sqrt(1+quot*quot))*SGVec3<T>(quot, -1, 0);
+  } else if (absv3 < absv2) {
+    T quot = v(2)/v(1);
+    return (1/sqrt(1+quot*quot))*SGVec3<T>(0, quot, -1);
+  } else if (SGLimits<T>::min() < absv3) {
+    T quot = v(0)/v(2);
+    return (1/sqrt(1+quot*quot))*SGVec3<T>(-1, 0, quot);
+  } else {
+    // the all zero case ...
+    return SGVec3<T>(0, 0, 0);
+  }
 }
 
 /// The euclidean norm of the vector, that is what most people call length
@@ -399,6 +424,43 @@ bool
 operator!=(const SGVec3<T>& v1, const SGVec3<T>& v2)
 { return ! (v1 == v2); }
 
+/// Return true if smaller, good for putting that into a std::map
+template<typename T>
+inline
+bool
+operator<(const SGVec3<T>& v1, const SGVec3<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 return (v1(2) < v2(2));
+}
+
+template<typename T>
+inline
+bool
+operator<=(const SGVec3<T>& v1, const SGVec3<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 return (v1(2) <= v2(2));
+}
+
+template<typename T>
+inline
+bool
+operator>(const SGVec3<T>& v1, const SGVec3<T>& v2)
+{ return operator<(v2, v1); }
+
+template<typename T>
+inline
+bool
+operator>=(const SGVec3<T>& v1, const SGVec3<T>& v2)
+{ return operator<=(v2, v1); }
+
 /// Return true if equal to the relative tolerance tol
 template<typename T>
 inline