+++ /dev/null
-/* -*- C++ -*- ------------------------------------------------------------
-
-Copyright (c) 2007 Jesse Anders and Demian Nave http://cmldev.net/
-
-The Configurable Math Library (CML) is distributed under the terms of the
-Boost Software License, v1.0 (see cml/LICENSE for details).
-
- *-----------------------------------------------------------------------*/
-/** @file
- * @brief Defines an operator for quaternion inverse.
- */
-
-#ifndef quaternion_inverse_h
-#define quaternion_inverse_h
-
-#include <cml/quaternion/quaternion_expr.h>
-#include <cml/quaternion/quaternion_functions.h>
-
-namespace cml {
-namespace et {
-
-/** An expression node for inverting a quaternion.
- *
- * This internally creates a ConjugateOp node to process the conjugate
- * of the given expression. The values produced by the ConjugateOp are then
- * divided by the Cayley norm of the expression on the fly.
- */
-template<class ExprT>
-class QuaternionInverseOp
-{
- public:
-
- typedef QuaternionInverseOp<ExprT> expr_type;
-
- /* Record ary-ness of the expression: */
- typedef unary_expression expr_ary;
-
- /* Copy the expression by value into higher-up expressions: */
- typedef expr_type expr_const_reference;
-
- /* The subexpression is a ConjugateOp: */
- typedef et::ConjugateOp<ExprT> subexpression_type;
- typedef ExprTraits<subexpression_type> expr_traits;
-
- /* Get traits for the ExprT: */
- typedef ExprTraits<ExprT> arg_traits;
- typedef typename arg_traits::const_reference arg_reference;
-
- typedef typename subexpression_type::value_type value_type;
- typedef quaternion_result_tag result_tag;
- typedef typename subexpression_type::size_tag size_tag;
-
- /* Reference type for the subexpression: */
- typedef typename expr_traits::const_reference expr_reference;
-
- /* Get the result type (same as for subexpression): */
- typedef typename expr_traits::result_type result_type;
-
- /* For matching by assignability: */
- typedef cml::et::not_assignable_tag assignable_tag;
-
- /* Get the temporary type: */
- typedef typename result_type::temporary_type temporary_type;
-
- /* Get the vector type: */
- typedef typename result_type::vector_type vector_type;
-
- /* Get the imaginary part type: */
- typedef typename vector_type::subvector_type imaginary_type;
-
- /* Record the order type: */
- typedef typename result_type::order_type order_type;
-
-
- public:
-
- /** Record result size as an enum. */
- enum { array_size = ExprT::array_size };
-
- /** Localize the ordering as an enum. */
- enum {
- W = order_type::W,
- X = order_type::X,
- Y = order_type::Y,
- Z = order_type::Z
- };
-
-
- public:
-
- /** Return the real part of the expression. */
- value_type real() const {
- return m_expr.real()/m_norm;
- }
-
- /** Return the vector part of the expression.
- *
- * @todo This could be returned as a VectorXpr also.
- */
- imaginary_type imaginary() const {
- return m_expr.imaginary()/m_norm;
- }
-
- /** Return the Cayley norm of the expression. */
- value_type norm() const {
- return length_squared();
- }
-
- /** Return square of the quaternion length. */
- value_type length_squared() const {
- return dot(
- QuaternionXpr<expr_type>(*this),
- QuaternionXpr<expr_type>(*this));
- }
-
- /** Return the quaternion length. */
- value_type length() const {
- return std::sqrt(length_squared());
- }
-
- /** Return the result as a normalized quaternion. */
- temporary_type normalize() const {
- temporary_type q(QuaternionXpr<expr_type>(*this));
- return q.normalize();
- }
-
- /** Compute inverse result at index i.
- *
- * The inverse of a quaternion p is ~p/norm(p).
- */
- value_type operator[](size_t i) const {
- return m_expr[i]/m_norm;
- }
-
-
- public:
-
- /** Return size of this expression (same as argument's size). */
- size_t size() const {
- return m_expr.size();
- }
-
- /** Return reference to contained expression. */
- expr_reference expression() const { return m_expr; }
-
-
- public:
-
- /** Construct from an input expression. */
- explicit QuaternionInverseOp(arg_reference arg)
- //: m_expr(arg), m_norm(cml::norm(arg)) {}
- : m_expr(arg), m_norm(arg.norm()) {}
-
- /** Copy constructor. */
- QuaternionInverseOp(const expr_type& e)
- : m_expr(e.m_expr), m_norm(e.m_norm) {}
-
-
- protected:
-
- subexpression_type m_expr;
- value_type m_norm;
-
-
- private:
-
- /* Cannot be assigned to: */
- expr_type& operator=(const expr_type&);
-};
-
-/** Expression traits class for QuaternionInverseOp<>. */
-template<class ExprT>
-struct ExprTraits< QuaternionInverseOp<ExprT> >
-{
- typedef QuaternionInverseOp<ExprT> expr_type;
- typedef ExprT arg_type;
-
- typedef typename expr_type::value_type value_type;
- typedef typename expr_type::expr_const_reference const_reference;
- typedef typename expr_type::result_tag result_tag;
- typedef typename expr_type::size_tag size_tag;
- typedef typename expr_type::result_type result_type;
- typedef typename expr_type::assignable_tag assignable_tag;
- typedef expr_node_tag node_tag;
-
- value_type get(const expr_type& v, size_t i) const { return v[i]; }
- size_t size(const expr_type& e) const { return e.size(); }
-};
-
-} // namespace et
-
-/** Inverse of a quaternion. */
-template<typename E, class AT, class OrderT, class CrossT> inline
-et::QuaternionXpr< et::QuaternionInverseOp< quaternion<E,AT,OrderT,CrossT> > >
-inverse(const quaternion<E,AT,OrderT,CrossT>& arg)
-{
- typedef et::QuaternionInverseOp< quaternion<E,AT,OrderT,CrossT> > ExprT;
- return et::QuaternionXpr<ExprT>(ExprT(arg));
-}
-
-/** Inverse of a QuaternionXpr. */
-template<class XprT> inline
-et::QuaternionXpr< et::QuaternionInverseOp<XprT> >
-inverse(QUATXPR_ARG_TYPE arg)
-{
- typedef et::QuaternionInverseOp<XprT> ExprT;
- return et::QuaternionXpr<ExprT>(ExprT(arg.expression()));
-}
-
-/* NOTE: Quaternion division no longer supported, but I'm leaving the
- code here for reference (Jesse) */
-
-#if 0
-/** Declare div taking two quaternion operands. */
-template<typename E1, class AT1, typename E2, class AT2, class OT, class CT>
-inline typename et::QuaternionPromote<
- quaternion<E1,AT1,OT,CT>, quaternion<E2,AT2,OT,CT>
->::temporary_type
-operator/(
- const quaternion<E1,AT1,OT,CT>& left,
- const quaternion<E2,AT2,OT,CT>& right)
-{
- return left*inverse(right);
-}
-
-/** Declare div taking a quaternion and a et::QuaternionXpr. */
-template<typename E, class AT, class OT, class CT, class XprT>
-inline typename et::QuaternionPromote<
- quaternion<E,AT,OT,CT>, typename XprT::result_type
->::temporary_type
-operator/(
- const quaternion<E,AT,OT,CT>& left,
- QUATXPR_ARG_TYPE right)
-{
- return left*inverse(right);
-}
-
-/** Declare div taking an et::QuaternionXpr and a quaternion. */
-template<class XprT, typename E, class AT, class OT, class CT>
-inline typename et::QuaternionPromote<
- typename XprT::result_type, quaternion<E,AT,OT,CT>
->::temporary_type
-operator/(
- QUATXPR_ARG_TYPE left,
- const quaternion<E,AT,OT,CT>& right)
-{
- return left*inverse(right);
-}
-
-/** Declare div taking two et::QuaternionXpr operands. */
-template<class XprT1, class XprT2>
-inline typename et::QuaternionPromote<
- typename XprT1::result_type, typename XprT2::result_type
->::temporary_type
-operator/(
- QUATXPR_ARG_TYPE_N(1) left,
- QUATXPR_ARG_TYPE_N(2) right)
-{
- return left*inverse(right);
-}
-#endif
-
-} // namespace cml
-
-#endif
-
-// -------------------------------------------------------------------------
-// vim:ft=cpp
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