Correct finite precision issues.

Use consistent function names.
Implement changes consistently over the different vector sizes.

Modified Files:
	SGVec2.hxx SGVec3.hxx SGVec4.hxx

diff --git a/simgear/math/SGVec2.hxx b/simgear/math/SGVec2.hxx
index 5024e2c19e56c00fe8d99fec47a160359886d14b..65c802ea3912ac5af7b18e7b7fdf332768b12f66 100644 (file)
--- a/simgear/math/SGVec2.hxx
+++ b/simgear/math/SGVec2.hxx
@@ -244,7 +244,12 @@ 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>
@@ -331,6 +336,18 @@ 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

diff --git a/simgear/math/SGVec3.hxx b/simgear/math/SGVec3.hxx
index 9b81ec57266f793c2f5e2dd569fcf8a6147df43e..64ceac0a88ac141ed6273738c624779745b2573f 100644 (file)
--- a/simgear/math/SGVec3.hxx
+++ b/simgear/math/SGVec3.hxx
@@ -358,9 +358,11 @@ template<typename T>
 inline
 SGVec3<T>
 normalize(const SGVec3<T>& v)
-{ T normv = norm(v);
-  if (normv > 0.0) return (1/norm(v))*v;
-  else return v;
+{
+  T normv = norm(v);
+  if (normv <= SGLimits<T>::min())
+    return SGVec3<T>::zeros();
+  return (1/normv)*v;
 }
 
 /// Return true if exactly the same
@@ -452,6 +454,18 @@ 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
@@ -480,15 +494,6 @@ SGVec3d
 toVec3d(const SGVec3f& v)
 { return SGVec3d(v(0), v(1), v(2)); }
 
-// calculate the projection of u along the direction of d.
-template<typename T>
-inline SGVec3<T> SGProjection(const SGVec3<T>& u, const SGVec3<T>& d)
-{
-  T denom = dot(d, d);
-  if (denom == 0.) return u;
-  else return  d * (dot(u,d) / denom);
-}
-
 #ifndef NO_OPENSCENEGRAPH_INTERFACE
 inline
 SGVec3d

diff --git a/simgear/math/SGVec4.hxx b/simgear/math/SGVec4.hxx
index baf9137daa2aba31e290c5c81a022f72d2254847..6030c48ba03e2ea331b43442cebfd2df509fdf1b 100644 (file)
--- a/simgear/math/SGVec4.hxx
+++ b/simgear/math/SGVec4.hxx
@@ -288,7 +288,12 @@ 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>
@@ -383,6 +388,18 @@ 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