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libsst/Lib/Include/CML/quaternion/quaternion_expr.h
2026-04-03 00:22:39 -05:00

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/* -*- 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
*/
#ifndef quaternion_expr_h
#define quaternion_expr_h
#include <cml/et/size_checking.h>
#include <cml/mathlib/epsilon.h>
#include <cml/quaternion/quaternion_traits.h>
#include <cml/quaternion/quaternion_promotions.h>
#include <cml/util.h>
#define QUATXPR_ARG_TYPE const et::QuaternionXpr<XprT>&
#define QUATXPR_ARG_TYPE_N(_N_) const et::QuaternionXpr<XprT##_N_>&
namespace cml {
namespace et {
/** A placeholder for a quaternion expression in an expression tree. */
template<class ExprT>
class QuaternionXpr
{
public:
typedef QuaternionXpr<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 quaternion_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;
/* 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;
/* For matching by assignability: */
typedef cml::et::not_assignable_tag assignable_tag;
/* Get the temporary type: */
typedef typename result_type::temporary_type temporary_type;
/* Record the order type: */
typedef typename result_type::order_type order_type;
/* Record the cross type: */
typedef typename result_type::cross_type cross_type;
public:
/** Record result size as an enum. */
enum { array_size = ExprT::array_size };
public:
/** Return the real part of the expression. */
value_type real() const {
return m_expr.real();
}
/** Return the vector part of the expression. */
imaginary_type imaginary() const {
return m_expr.imaginary();
}
/** Return the Cayley norm of the expression. */
value_type norm() const {
return m_expr.length_squared();
}
/** Return square of the quaternion length. */
value_type length_squared() const {
return m_expr.length_squared();
}
/** Return the quaternion length. */
value_type length() const {
return m_expr.length();
}
/** Return the result as a normalized quaternion. */
temporary_type normalize() const {
return m_expr.normalize();
}
/** Return the log of the expression. */
temporary_type log(
value_type tolerance = epsilon<value_type>::placeholder()) const
{
return m_expr.log(tolerance);
}
/**
* Return the result of the exponential function as applied to
* this expression.
*/
temporary_type exp(
value_type tolerance = epsilon<value_type>::placeholder()) const
{
return m_expr.exp(tolerance);
}
/** Compute value at index i of the result quaternion. */
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 QuaternionXpr(expr_reference expr) : m_expr(expr) {}
/** Copy constructor. */
QuaternionXpr(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 QuaternionXpr<>. */
template<class ExprT>
struct ExprTraits< QuaternionXpr<ExprT> >
{
typedef QuaternionXpr<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 not_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 quaternion expression.
*
* The operator's operator() method must take exactly one argument.
*/
template<class ExprT, class OpT>
class UnaryQuaternionOp
{
public:
typedef UnaryQuaternionOp<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 quaternion_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;
/* 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 (*this)[W];
}
/** Return the vector part of the expression. */
imaginary_type imaginary() const {
imaginary_type v;
v[0] = (*this)[X]; v[1] = (*this)[Y]; v[2] = (*this)[Z];
return v;
}
/** 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();
}
/** Return the log of this expression. */
temporary_type log(
value_type tolerance = epsilon<value_type>::placeholder()) const
{
value_type a = acos_safe(real());
value_type s = std::sin(a);
if (s > tolerance) {
return temporary_type(value_type(0), imaginary() * (a / s));
} else {
return temporary_type(value_type(0), imaginary());
}
}
/**
* Return the result of the exponential function as applied to
* this expression.
*/
temporary_type exp(
value_type tolerance = epsilon<value_type>::placeholder()) const
{
imaginary_type v = imaginary();
value_type a = cml::length(v);
if (a > tolerance) {
return temporary_type(std::cos(a), v * (std::sin(a) / a));
} else {
return temporary_type(std::cos(a), v);
}
}
/** Compute value at index i of the result quaternion. */
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 UnaryQuaternionOp(expr_reference expr) : m_expr(expr) {}
/** Copy constructor. */
UnaryQuaternionOp(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 UnaryQuaternionOp<>. */
template<class ExprT, class OpT>
struct ExprTraits< UnaryQuaternionOp<ExprT,OpT> >
{
typedef UnaryQuaternionOp<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 not_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 quaternion expression.
*
* The operator's operator() method must take exactly two arguments.
*/
template<class LeftT, class RightT, class OpT>
class BinaryQuaternionOp
{
public:
typedef BinaryQuaternionOp<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 quaternion_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 (quaternion) type: */
typedef typename left_traits::result_type left_result;
typedef typename right_traits::result_type right_result;
typedef typename QuaternionPromote<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;
/* 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;
/* Define a size checker: */
typedef GetCheckedSize<LeftT,RightT,size_tag> checked_size;
public:
/** Record result size as an enum. */
enum { array_size = 4 };
/** 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 (*this)[W];
}
/** Return the vector part of the expression. */
imaginary_type imaginary() const {
imaginary_type v;
v[0] = (*this)[X]; v[1] = (*this)[Y]; v[2] = (*this)[Z];
return v;
}
/** 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();
}
/** Return the log of this expression. */
temporary_type log(
value_type tolerance = epsilon<value_type>::placeholder()) const
{
value_type a = acos_safe(real());
value_type s = std::sin(a);
if (s > tolerance) {
return temporary_type(value_type(0), imaginary() * (a / s));
} else {
return temporary_type(value_type(0), imaginary());
}
}
/**
* Return the result of the exponential function as applied to
* this expression.
*/
temporary_type exp(
value_type tolerance = epsilon<value_type>::placeholder()) const
{
imaginary_type v = imaginary();
value_type a = cml::length(v);
if (a > tolerance) {
return temporary_type(std::cos(a), v * (std::sin(a) / a));
} else {
return temporary_type(std::cos(a), v);
}
}
/** Compute value at index i of the result quaternion. */
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 quaternion 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:
*/
CheckedSize(m_left,m_right,size_tag());
/* The size is always 4: */
return 4;
}
/** 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 BinaryQuaternionOp(left_reference left, right_reference right)
: m_left(left), m_right(right) {}
/** Copy constructor. */
BinaryQuaternionOp(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 BinaryQuaternionOp<>. */
template<class LeftT, class RightT, class OpT>
struct ExprTraits< BinaryQuaternionOp<LeftT,RightT,OpT> >
{
typedef BinaryQuaternionOp<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::imaginary_type imaginary_type;
typedef typename expr_type::assignable_tag not_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 quaternion expressions: */
template<class LeftTraits, class RightTraits>
struct QuaternionExpressions
{
/* Require that both arguments are quaternion expressions: */
typedef typename LeftTraits::result_tag left_result;
typedef typename RightTraits::result_tag right_result;
enum { is_true = (same_type<left_result,et::quaternion_result_tag>::is_true
&& same_type<right_result,et::quaternion_result_tag>::is_true) };
};
} // namespace et
} // namespace cml
#endif
// -------------------------------------------------------------------------
// vim:ft=cpp