1 | // This file is part of Eigen, a lightweight C++ template library |
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2 | // for linear algebra. Eigen itself is part of the KDE project. |
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3 | // |
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4 | // Copyright (C) 2008 Gael Guennebaud <g.gael@free.fr> |
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5 | // |
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6 | // This Source Code Form is subject to the terms of the Mozilla |
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7 | // Public License v. 2.0. If a copy of the MPL was not distributed |
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8 | // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. |
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9 | |
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10 | // no include guard, we'll include this twice from All.h from Eigen2Support, and it's internal anyway |
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11 | |
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12 | namespace Eigen { |
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13 | |
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14 | /** \geometry_module \ingroup Geometry_Module |
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15 | * |
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16 | * \class Scaling |
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17 | * |
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18 | * \brief Represents a possibly non uniform scaling transformation |
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19 | * |
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20 | * \param _Scalar the scalar type, i.e., the type of the coefficients. |
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21 | * \param _Dim the dimension of the space, can be a compile time value or Dynamic |
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22 | * |
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23 | * \note This class is not aimed to be used to store a scaling transformation, |
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24 | * but rather to make easier the constructions and updates of Transform objects. |
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25 | * |
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26 | * \sa class Translation, class Transform |
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27 | */ |
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28 | template<typename _Scalar, int _Dim> |
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29 | class Scaling |
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30 | { |
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31 | public: |
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32 | EIGEN_MAKE_ALIGNED_OPERATOR_NEW_IF_VECTORIZABLE_FIXED_SIZE(_Scalar,_Dim) |
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33 | /** dimension of the space */ |
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34 | enum { Dim = _Dim }; |
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35 | /** the scalar type of the coefficients */ |
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36 | typedef _Scalar Scalar; |
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37 | /** corresponding vector type */ |
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38 | typedef Matrix<Scalar,Dim,1> VectorType; |
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39 | /** corresponding linear transformation matrix type */ |
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40 | typedef Matrix<Scalar,Dim,Dim> LinearMatrixType; |
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41 | /** corresponding translation type */ |
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42 | typedef Translation<Scalar,Dim> TranslationType; |
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43 | /** corresponding affine transformation type */ |
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44 | typedef Transform<Scalar,Dim> TransformType; |
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45 | |
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46 | protected: |
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47 | |
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48 | VectorType m_coeffs; |
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49 | |
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50 | public: |
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51 | |
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52 | /** Default constructor without initialization. */ |
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53 | Scaling() {} |
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54 | /** Constructs and initialize a uniform scaling transformation */ |
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55 | explicit inline Scaling(const Scalar& s) { m_coeffs.setConstant(s); } |
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56 | /** 2D only */ |
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57 | inline Scaling(const Scalar& sx, const Scalar& sy) |
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58 | { |
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59 | ei_assert(Dim==2); |
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60 | m_coeffs.x() = sx; |
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61 | m_coeffs.y() = sy; |
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62 | } |
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63 | /** 3D only */ |
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64 | inline Scaling(const Scalar& sx, const Scalar& sy, const Scalar& sz) |
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65 | { |
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66 | ei_assert(Dim==3); |
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67 | m_coeffs.x() = sx; |
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68 | m_coeffs.y() = sy; |
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69 | m_coeffs.z() = sz; |
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70 | } |
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71 | /** Constructs and initialize the scaling transformation from a vector of scaling coefficients */ |
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72 | explicit inline Scaling(const VectorType& coeffs) : m_coeffs(coeffs) {} |
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73 | |
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74 | const VectorType& coeffs() const { return m_coeffs; } |
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75 | VectorType& coeffs() { return m_coeffs; } |
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76 | |
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77 | /** Concatenates two scaling */ |
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78 | inline Scaling operator* (const Scaling& other) const |
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79 | { return Scaling(coeffs().cwise() * other.coeffs()); } |
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80 | |
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81 | /** Concatenates a scaling and a translation */ |
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82 | inline TransformType operator* (const TranslationType& t) const; |
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83 | |
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84 | /** Concatenates a scaling and an affine transformation */ |
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85 | inline TransformType operator* (const TransformType& t) const; |
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86 | |
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87 | /** Concatenates a scaling and a linear transformation matrix */ |
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88 | // TODO returns an expression |
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89 | inline LinearMatrixType operator* (const LinearMatrixType& other) const |
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90 | { return coeffs().asDiagonal() * other; } |
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91 | |
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92 | /** Concatenates a linear transformation matrix and a scaling */ |
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93 | // TODO returns an expression |
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94 | friend inline LinearMatrixType operator* (const LinearMatrixType& other, const Scaling& s) |
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95 | { return other * s.coeffs().asDiagonal(); } |
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96 | |
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97 | template<typename Derived> |
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98 | inline LinearMatrixType operator*(const RotationBase<Derived,Dim>& r) const |
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99 | { return *this * r.toRotationMatrix(); } |
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100 | |
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101 | /** Applies scaling to vector */ |
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102 | inline VectorType operator* (const VectorType& other) const |
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103 | { return coeffs().asDiagonal() * other; } |
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104 | |
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105 | /** \returns the inverse scaling */ |
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106 | inline Scaling inverse() const |
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107 | { return Scaling(coeffs().cwise().inverse()); } |
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108 | |
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109 | inline Scaling& operator=(const Scaling& other) |
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110 | { |
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111 | m_coeffs = other.m_coeffs; |
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112 | return *this; |
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113 | } |
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114 | |
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115 | /** \returns \c *this with scalar type casted to \a NewScalarType |
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116 | * |
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117 | * Note that if \a NewScalarType is equal to the current scalar type of \c *this |
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118 | * then this function smartly returns a const reference to \c *this. |
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119 | */ |
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120 | template<typename NewScalarType> |
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121 | inline typename internal::cast_return_type<Scaling,Scaling<NewScalarType,Dim> >::type cast() const |
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122 | { return typename internal::cast_return_type<Scaling,Scaling<NewScalarType,Dim> >::type(*this); } |
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123 | |
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124 | /** Copy constructor with scalar type conversion */ |
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125 | template<typename OtherScalarType> |
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126 | inline explicit Scaling(const Scaling<OtherScalarType,Dim>& other) |
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127 | { m_coeffs = other.coeffs().template cast<Scalar>(); } |
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128 | |
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129 | /** \returns \c true if \c *this is approximately equal to \a other, within the precision |
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130 | * determined by \a prec. |
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131 | * |
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132 | * \sa MatrixBase::isApprox() */ |
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133 | bool isApprox(const Scaling& other, typename NumTraits<Scalar>::Real prec = precision<Scalar>()) const |
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134 | { return m_coeffs.isApprox(other.m_coeffs, prec); } |
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135 | |
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136 | }; |
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137 | |
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138 | /** \addtogroup Geometry_Module */ |
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139 | //@{ |
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140 | typedef Scaling<float, 2> Scaling2f; |
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141 | typedef Scaling<double,2> Scaling2d; |
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142 | typedef Scaling<float, 3> Scaling3f; |
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143 | typedef Scaling<double,3> Scaling3d; |
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144 | //@} |
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145 | |
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146 | template<typename Scalar, int Dim> |
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147 | inline typename Scaling<Scalar,Dim>::TransformType |
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148 | Scaling<Scalar,Dim>::operator* (const TranslationType& t) const |
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149 | { |
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150 | TransformType res; |
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151 | res.matrix().setZero(); |
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152 | res.linear().diagonal() = coeffs(); |
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153 | res.translation() = m_coeffs.cwise() * t.vector(); |
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154 | res(Dim,Dim) = Scalar(1); |
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155 | return res; |
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156 | } |
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157 | |
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158 | template<typename Scalar, int Dim> |
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159 | inline typename Scaling<Scalar,Dim>::TransformType |
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160 | Scaling<Scalar,Dim>::operator* (const TransformType& t) const |
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161 | { |
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162 | TransformType res = t; |
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163 | res.prescale(m_coeffs); |
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164 | return res; |
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165 | } |
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166 | |
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167 | } // end namespace Eigen |
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