--- /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 Vector linear expression classes.
+ */
+
+#ifndef vector_expr_h
+#define vector_expr_h
+
+#include <cmath>
+#include <cml/et/size_checking.h>
+#include <cml/vector/vector_traits.h>
+#include <cml/vector/vector_promotions.h>
+
+/* XXX Don't know which it should be just yet, since RVO seems to obviate need
+ * for a reference type. However, copy by value copies the *entire expression
+ * tree rooted at the VectorXpr<>, so this choice is bound to affect
+ * performace for some compiler or another:
+ */
+#define VECXPR_ARG_TYPE const et::VectorXpr<XprT>&
+#define VECXPR_ARG_TYPE_N(_N_) const et::VectorXpr<XprT##_N_>&
+
+//#define VECXPR_ARG_TYPE const et::VectorXpr<XprT>
+//#define VECXPR_ARG_TYPE_N(_N_) const et::VectorXpr<XprT##_N_>
+
+namespace cml {
+namespace et {
+
+/** A placeholder for a vector expression in an expression tree. */
+template<class ExprT>
+class VectorXpr
+{
+ public:
+
+ typedef VectorXpr<ExprT> expr_type;
+
+ /* Record ary-ness of the expression: */
+ typedef typename ExprT::expr_ary expr_ary;
+
+ /* Copy the expression by value into higher-up expressions: */
+ typedef expr_type expr_const_reference;
+
+ typedef typename ExprT::value_type value_type;
+ typedef vector_result_tag result_tag;
+ typedef typename ExprT::size_tag size_tag;
+
+ /* Store the expression traits: */
+ typedef ExprTraits<ExprT> expr_traits;
+
+ /* Get the reference type: */
+ typedef typename expr_traits::const_reference expr_reference;
+
+ /* Get the result type: */
+ 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;
+
+
+ public:
+
+ /** Record result size as an enum. */
+ enum { array_size = ExprT::array_size };
+
+
+ public:
+
+ /** Return square of the length. */
+ value_type length_squared() const {
+ return m_expr.length_squared();
+ }
+
+ /** Return the length. */
+ value_type length() const {
+ return m_expr.length();
+ }
+
+ /** Return the result as a normalized vector. */
+ result_type normalize() const {
+ return m_expr.normalize();
+ }
+
+ /** Compute value at index i of the result vector. */
+ value_type operator[](size_t i) const {
+ return m_expr[i];
+ }
+
+
+ public:
+
+ /** Return size of this expression (same as subexpression'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 the subexpression to store. */
+ explicit VectorXpr(expr_reference expr) : m_expr(expr) {}
+
+ /** Copy constructor. */
+ VectorXpr(const expr_type& e) : m_expr(e.m_expr) {}
+
+
+ protected:
+
+ expr_reference m_expr;
+
+
+ private:
+
+ /* Cannot be assigned to: */
+ expr_type& operator=(const expr_type&);
+};
+
+/** Expression traits class for VectorXpr<>. */
+template<class ExprT>
+struct ExprTraits< VectorXpr<ExprT> >
+{
+ typedef VectorXpr<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(); }
+};
+
+
+/** A unary vector expression.
+ *
+ * The operator's operator() method must take exactly one argument.
+ */
+template<class ExprT, class OpT>
+class UnaryVectorOp
+{
+ public:
+
+ typedef UnaryVectorOp<ExprT,OpT> 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;
+
+ typedef typename OpT::value_type value_type;
+ typedef vector_result_tag result_tag;
+ typedef typename ExprT::size_tag size_tag;
+
+ /* Store the expression traits for the subexpression: */
+ typedef ExprTraits<ExprT> expr_traits;
+
+ /* 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;
+
+
+ public:
+
+ /** Record result size as an enum. */
+ enum { array_size = ExprT::array_size };
+
+
+ public:
+
+ /** Return square of the length. */
+ value_type length_squared() const {
+ return dot(
+ VectorXpr<expr_type>(*this),
+ VectorXpr<expr_type>(*this));
+ }
+
+ /** Return the length. */
+ value_type length() const {
+ return std::sqrt(length_squared());
+ }
+
+ /** Return the result as a normalized vector. */
+ result_type normalize() const {
+ result_type v(VectorXpr<expr_type>(*this));
+ return v.normalize();
+ }
+
+ /** Compute value at index i of the result vector. */
+ value_type operator[](size_t i) const {
+
+ /* This uses the expression traits to figure out how to access the
+ * i'th index of the subexpression:
+ */
+ return OpT().apply(expr_traits().get(m_expr,i));
+ }
+
+
+ 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 the subexpression. */
+ explicit UnaryVectorOp(expr_reference expr) : m_expr(expr) {}
+
+ /** Copy constructor. */
+ UnaryVectorOp(const expr_type& e) : m_expr(e.m_expr) {}
+
+
+ protected:
+
+ expr_reference m_expr;
+
+
+ private:
+
+ /* Cannot be assigned to: */
+ expr_type& operator=(const expr_type&);
+};
+
+/** Expression traits class for UnaryVectorOp<>. */
+template<class ExprT, class OpT>
+struct ExprTraits< UnaryVectorOp<ExprT,OpT> >
+{
+ typedef UnaryVectorOp<ExprT,OpT> 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(); }
+};
+
+
+/** A binary vector expression.
+ *
+ * The operator's operator() method must take exactly two arguments.
+ */
+template<class LeftT, class RightT, class OpT>
+class BinaryVectorOp
+{
+ public:
+
+ typedef BinaryVectorOp<LeftT,RightT,OpT> expr_type;
+
+ /* Record ary-ness of the expression: */
+ typedef binary_expression expr_ary;
+
+ /* Copy the expression by value into higher-up expressions: */
+ typedef expr_type expr_const_reference;
+
+ typedef typename OpT::value_type value_type;
+ typedef vector_result_tag result_tag;
+
+ /* Store the expression traits types for the two subexpressions: */
+ typedef ExprTraits<LeftT> left_traits;
+ typedef ExprTraits<RightT> right_traits;
+
+ /* Reference types for the two subexpressions: */
+ typedef typename left_traits::const_reference left_reference;
+ typedef typename right_traits::const_reference right_reference;
+
+ /* Figure out the expression's resulting (vector) type: */
+ typedef typename left_traits::result_type left_result;
+ typedef typename right_traits::result_type right_result;
+ typedef typename VectorPromote<left_result,right_result>::type result_type;
+ typedef typename result_type::size_tag size_tag;
+
+ /* For matching by assignability: */
+ typedef cml::et::not_assignable_tag assignable_tag;
+
+ /* Get the temporary type: */
+ typedef typename result_type::temporary_type temporary_type;
+
+ /* Define a size checker: */
+ typedef GetCheckedSize<LeftT,RightT,size_tag> checked_size;
+
+
+ public:
+
+ /** Record result size as an enum (if applicable). */
+ enum { array_size = result_type::array_size };
+
+
+ public:
+
+ /** Return square of the length. */
+ value_type length_squared() const {
+ return dot(
+ VectorXpr<expr_type>(*this),
+ VectorXpr<expr_type>(*this));
+ }
+
+ /** Return the length. */
+ value_type length() const {
+ return std::sqrt(length_squared());
+ }
+
+ /** Return the result as a normalized vector. */
+ result_type normalize() const {
+ result_type v(VectorXpr<expr_type>(*this));
+ return v.normalize();
+ }
+
+ /** Compute value at index i of the result vector. */
+ value_type operator[](size_t i) const {
+
+ /* This uses the expression traits to figure out how to access the
+ * i'th index of the two subexpressions:
+ */
+ return OpT().apply(
+ left_traits().get(m_left,i),
+ right_traits().get(m_right,i));
+ }
+
+
+ public:
+
+ /** Return the size of the vector result.
+ *
+ * @throws std::invalid_argument if the expressions do not have the same
+ * size.
+ */
+ size_t size() const {
+ /* Note: This actually does a check only if
+ * CML_CHECK_VECTOR_EXPR_SIZES is set:
+ */
+ return CheckedSize(m_left,m_right,size_tag());
+ }
+
+ /** Return reference to left expression. */
+ left_reference left_expression() const { return m_left; }
+
+ /** Return reference to right expression. */
+ right_reference right_expression() const { return m_right; }
+
+
+ public:
+
+ /** Construct from the two subexpressions. */
+ explicit BinaryVectorOp(left_reference left, right_reference right)
+ : m_left(left), m_right(right) {}
+
+ /** Copy constructor. */
+ BinaryVectorOp(const expr_type& e)
+ : m_left(e.m_left), m_right(e.m_right) {}
+
+
+ protected:
+
+ left_reference m_left;
+ right_reference m_right;
+
+
+ private:
+
+ /* This ensures that a compile-time size check is executed: */
+ typename checked_size::check_type _dummy;
+
+
+ private:
+
+ /* Cannot be assigned to: */
+ expr_type& operator=(const expr_type&);
+};
+
+/** Expression traits class for BinaryVectorOp<>. */
+template<class LeftT, class RightT, class OpT>
+struct ExprTraits< BinaryVectorOp<LeftT,RightT,OpT> >
+{
+ typedef BinaryVectorOp<LeftT,RightT,OpT> expr_type;
+ typedef LeftT left_type;
+ typedef RightT right_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(); }
+};
+
+/* Helper struct to verify that both arguments are vector expressions: */
+template<typename LeftTraits, typename RightTraits>
+struct VectorExpressions
+{
+ /* Require that both arguments are vector expressions: */
+ typedef typename LeftTraits::result_tag left_result;
+ typedef typename RightTraits::result_tag right_result;
+ enum { is_true = (same_type<left_result,et::vector_result_tag>::is_true
+ && same_type<right_result,et::vector_result_tag>::is_true) };
+};
+
+namespace detail {
+
+template<typename VecT, typename RT, typename MT> inline
+void Resize(VecT&,size_t,RT,MT) {}
+
+template<typename VecT> inline
+void Resize(VecT& v, size_t S, resizable_tag, dynamic_memory_tag) {
+ v.resize(S);
+}
+
+template<typename VecT> inline
+void Resize(VecT& v, size_t S) {
+ Resize(v, S, typename VecT::resizing_tag(), typename VecT::memory_tag());
+}
+
+} // namespace detail
+
+} // namespace et
+} // namespace cml
+
+#endif
+
+// -------------------------------------------------------------------------
+// vim:ft=cpp
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