Add reflection transformation operator (#66)

Author: rmrsk

Source/EBGeometry_AnalyticDistanceFunctions.hpp

@@ -844,6 +844,7 @@ class RoundedBoxSDF : public SignedDistanceFunction<T>
 
   /*!
     @brief Full constructor. User inputs dimensions and corner curvature. 
+    @note The extensions of the box in each direction 'dir' is a_dimensions[dir] + a_curvature. 
     @param[in] a_dimensions Box dimensions (width, length, height)
     @param[in] a_curvature Corner curvature. 
     @note Curvature must be > 0.0

Source/EBGeometry_Transform.hpp

@@ -101,6 +101,15 @@ template <class T>
 std::shared_ptr<ImplicitFunction<T>>
 Elongate(const std::shared_ptr<ImplicitFunction<T>>& a_implicitFunction, const Vec3T<T>& a_elongation) noexcept;
 
+/*!
+  @brief Convenience function for reflecting an implicit function
+  @param[in] a_implicitFunction Implicit function to be reflected
+  @param[in] a_reflectPlane Plane to reflect across  (0=yz-plane, 1=xz-plane, 2=xy-plane).
+*/
+template <class T>
+std::shared_ptr<ImplicitFunction<T>>
+Reflect(const std::shared_ptr<ImplicitFunction<T>>& a_implicitFunction, const size_t& a_reflectPlane) noexcept;
+
 /*!
   @brief Complemented implicit function
 */
@@ -517,6 +526,49 @@ class ElongateIF : public ImplicitFunction<T>
   Vec3T<T> m_elongation;
 };
 
+/*!
+  @brief Implicit function which is a reflection of another implicit function
+*/
+template <class T>
+class ReflectIF : public ImplicitFunction<T>
+{
+public:
+  /*!
+    @brief Disallowed weak construction
+  */
+  ReflectIF() = delete;
+
+  /*!
+    @brief Full constructor. Reflects around the input plane (0=yz-plane, 1=xz-plane, 2=xy-plane).
+    @param[in] a_implicitFunction Implicit function to be reflected
+    @param[in] a_reflectPlane Plane to reflect across
+  */
+  ReflectIF(const std::shared_ptr<ImplicitFunction<T>>& a_implicitFunction, const size_t& a_reflectPlane) noexcept;
+
+  /*!
+    @brief Destructor
+  */
+  virtual ~ReflectIF() noexcept;
+
+  /*!
+    @brief Value function
+    @param[in] a_point input point
+  */
+  virtual T
+  value(const Vec3T<T>& a_point) const noexcept override;
+
+protected:
+  /*!
+    @brief Underlying implicit function to be reflected
+  */
+  std::shared_ptr<const ImplicitFunction<T>> m_implicitFunction;
+
+  /*!
+    @brief Reflection parameters
+  */
+  Vec3T<T> m_reflectParams;
+};
+
 #include "EBGeometry_NamespaceFooter.hpp"
 
 #include "EBGeometry_TransformImplem.hpp"

Source/EBGeometry_TransformImplem.hpp

@@ -84,6 +84,13 @@ Elongate(const std::shared_ptr<ImplicitFunction<T>>& a_implicitFunction, const V
   return std::make_shared<ElongateIF<T>>(a_implicitFunction, a_elongation);
 }
 
+template <class T>
+std::shared_ptr<ImplicitFunction<T>>
+Reflect(const std::shared_ptr<ImplicitFunction<T>>& a_implicitFunction, const size_t& a_reflectPlane) noexcept
+{
+  return std::make_shared<ReflectIF<T>>(a_implicitFunction, a_reflectPlane);
+}
+
 template <class T>
 ComplementIF<T>::ComplementIF(const std::shared_ptr<ImplicitFunction<T>>& a_implicitFunction) noexcept
 
@@ -349,6 +356,29 @@ ElongateIF<T>::value(const Vec3T<T>& a_point) const noexcept
   return m_implicitFunction->value(a_point - clamp(a_point, -m_elongation, m_elongation));
 }
 
+template <class T>
+ReflectIF<T>::ReflectIF(const std::shared_ptr<ImplicitFunction<T>>& a_implicitFunction,
+                        const size_t&                               a_reflectPlane) noexcept
+{
+  m_implicitFunction = a_implicitFunction;
+  m_reflectParams    = Vec3T<T>::one();
+
+  if (a_reflectPlane >= 0 && a_reflectPlane <= 2) {
+    m_reflectParams[a_reflectPlane] = -1;
+  }
+}
+
+template <class T>
+ReflectIF<T>::~ReflectIF() noexcept
+{}
+
+template <class T>
+T
+ReflectIF<T>::value(const Vec3T<T>& a_point) const noexcept
+{
+  return m_implicitFunction->value(a_point * m_reflectParams);
+}
+
 #include "EBGeometry_NamespaceFooter.hpp"
 
 #endif