From c06ae325a4332d52e0c6049b4e7d99ac4887b26a Mon Sep 17 00:00:00 2001
From: Andy Somerville <andy.somerville@gmail.com>
Date: Sat, 10 Dec 2011 11:58:38 +0100
Subject: [PATCH] feature 297: add ParametrizedLine::intersectionPoint() and
 intersectionParam() -> intersection() is deprecated

---
 Eigen/src/Geometry/ParametrizedLine.h | 46 +++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/Eigen/src/Geometry/ParametrizedLine.h b/Eigen/src/Geometry/ParametrizedLine.h
index b90f9c088..4e4d52f9b 100644
--- a/Eigen/src/Geometry/ParametrizedLine.h
+++ b/Eigen/src/Geometry/ParametrizedLine.h
@@ -106,8 +106,21 @@ public:
   VectorType projection(const VectorType& p) const
   { return origin() + direction().dot(p-origin()) * direction(); }
 
+  /** \returns the point at parameter t along the line */
+  VectorType intersectionPoint( Scalar t ) const;
+  
+  /** \returns parameter t of the intersection of the line with hyperplane */
+  template <int OtherOptions>
+  Scalar intersectionParameter(const Hyperplane<_Scalar, _AmbientDim, OtherOptions>& hyperplane) const;
+ 
+  /** \returns parameter t of the intersection of the line with hyperplane. (maintained for API compatablity) */
   template <int OtherOptions>
   Scalar intersection(const Hyperplane<_Scalar, _AmbientDim, OtherOptions>& hyperplane) const;
+  
+  /** \returns the intersection point of the line with hyperplane */
+  template <int OtherOptions>
+  VectorType intersectionPoint(const Hyperplane<_Scalar, _AmbientDim, OtherOptions>& hyperplane) const;
+
 
   /** \returns \c *this with scalar type casted to \a NewScalarType
     *
@@ -155,14 +168,43 @@ inline ParametrizedLine<_Scalar, _AmbientDim,_Options>::ParametrizedLine(const H
   origin() = -hyperplane.normal()*hyperplane.offset();
 }
 
+/** \returns the point at t along this line
+  */
+template <typename _Scalar, int _AmbientDim, int _Options>
+inline typename ParametrizedLine<_Scalar, _AmbientDim,_Options>::VectorType
+ParametrizedLine<_Scalar, _AmbientDim,_Options>::intersectionPoint( _Scalar t ) const
+{
+  return origin() + (direction()*t); 
+}
+
+/** \returns the parameter value of the intersection between \c *this and the given hyperplane
+  */
+template <typename _Scalar, int _AmbientDim, int _Options>
+template <int OtherOptions>
+inline _Scalar ParametrizedLine<_Scalar, _AmbientDim,_Options>::intersectionParameter(const Hyperplane<_Scalar, _AmbientDim, OtherOptions>& hyperplane) const
+{
+  return -(hyperplane.offset()+hyperplane.normal().dot(origin()))
+          / hyperplane.normal().dot(direction());
+}
+
+
 /** \returns the parameter value of the intersection between \c *this and the given hyperplane
   */
 template <typename _Scalar, int _AmbientDim, int _Options>
 template <int OtherOptions>
 inline _Scalar ParametrizedLine<_Scalar, _AmbientDim,_Options>::intersection(const Hyperplane<_Scalar, _AmbientDim, OtherOptions>& hyperplane) const
 {
-  return -(hyperplane.offset()+hyperplane.normal().dot(origin()))
-          / hyperplane.normal().dot(direction());
+  return intersectionParameter(hyperplane);
+}
+
+/** \returns the point of the intersection between \c *this and the given hyperplane
+  */
+template <typename _Scalar, int _AmbientDim, int _Options>
+template <int OtherOptions>
+inline typename ParametrizedLine<_Scalar, _AmbientDim,_Options>::VectorType
+ParametrizedLine<_Scalar, _AmbientDim,_Options>::intersectionPoint(const Hyperplane<_Scalar, _AmbientDim, OtherOptions>& hyperplane) const
+{
+  return intersectionPoint(intersectionParameter(hyperplane)); 
 }
 
 #endif // EIGEN_PARAMETRIZEDLINE_H