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+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra. Eigen itself is part of the KDE project.
+//
+// Copyright (C) 2008 Gael Guennebaud <g.gael@free.fr>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef EIGEN_SCALING_H
+#define EIGEN_SCALING_H
+
+/** \geometry_module \ingroup GeometryModule
+ *
+ * \class Scaling
+ *
+ * \brief Represents a possibly non uniform scaling transformation
+ *
+ * \param _Scalar the scalar type, i.e., the type of the coefficients.
+ * \param _Dim the dimension of the space, can be a compile time value or Dynamic
+ *
+ *
+ * \sa class Translate, class Transform
+ */
+template<typename _Scalar, int _Dim>
+class Scaling
+{
+public:
+ enum { Dim = _Dim };
+ /** the scalar type of the coefficients */
+ typedef _Scalar Scalar;
+ typedef Matrix<Scalar,Dim,Dim> LinearMatrixType;
+ typedef Matrix<Scalar,Dim,1> VectorType;
+ typedef Translation<Scalar,Dim> TranslationType;
+ typedef Transform<Scalar,Dim> TransformType;
+
+protected:
+
+ VectorType m_coeffs;
+
+public:
+
+ /** Default constructor without initialization. */
+ Scaling() {}
+ /** Constructs and initialize a uniform scaling transformation */
+ explicit inline Scaling(const Scalar& s) { m_coeffs.setConstant(s); }
+ /** 2D only */
+ inline Scaling(const Scalar& sx, const Scalar& sy)
+ {
+ ei_assert(Dim==2);
+ m_coeffs.x() = sx;
+ m_coeffs.y() = sy;
+ }
+ /** 3D only */
+ inline Scaling(const Scalar& sx, const Scalar& sy, const Scalar& sz)
+ {
+ ei_assert(Dim==3);
+ m_coeffs.x() = sx;
+ m_coeffs.y() = sy;
+ m_coeffs.z() = sz;
+ }
+ /** Constructs and initialize the scaling transformation from a vector of scaling coefficients */
+ explicit inline Scaling(const VectorType& coeffs) : m_coeffs(coeffs) {}
+
+ const VectorType& coeffs() const { return m_coeffs; }
+ VectorType& coeffs() { return m_coeffs; }
+
+ /** Concatenates two scaling */
+ inline Scaling operator* (const Scaling& other) const
+ { return Scaling(coeffs().cwise() * other.coeffs()); }
+
+ /** Concatenates a scaling and a translation */
+ inline TransformType operator* (const TranslationType& t) const;
+
+ /** Concatenates a scaling and an affine transformation */
+ inline TransformType operator* (const TransformType& t) const;
+
+ /** Concatenates a scaling and a linear transformation matrix */
+ // TODO returns an expression
+ inline LinearMatrixType operator* (const LinearMatrixType& other) const
+ { return coeffs().asDiagonal() * other; }
+
+ /** Concatenates a linear transformation matrix and a scaling */
+ // TODO returns an expression
+ friend inline LinearMatrixType operator* (const LinearMatrixType& other, const Scaling& s)
+ { return other * s.coeffs().asDiagonal(); }
+
+ /** Applies scaling to vector */
+ inline VectorType operator* (const VectorType& other) const
+ { return coeffs().asDiagonal() * other; }
+
+ /** \returns the inverse scaling */
+ inline Scaling inverse() const
+ { return Scaling(coeffs.cwise().inverse()); }
+
+ inline Scaling& operator=(const Scaling& other)
+ {
+ m_coeffs = other.m_coeffs;
+ return *this;
+ }
+
+};
+
+/** \addtogroup GeometryModule */
+//@{
+typedef Scaling<float, 2> Scaling2f;
+typedef Scaling<double,2> Scaling2d;
+typedef Scaling<float, 3> Scaling3f;
+typedef Scaling<double,3> Scaling3d;
+//@}
+
+template<typename Scalar, int Dim>
+inline typename Scaling<Scalar,Dim>::TransformType
+Scaling<Scalar,Dim>::operator* (const TranslationType& t) const
+{
+ TransformType res;
+ res.matrix().setZero();
+ res.linear().diagonal() = coeffs();
+ res.translation() = m_coeffs.cwise() * t.vector();
+ res(Dim,Dim) = Scalar(1);
+ return res;
+}
+
+template<typename Scalar, int Dim>
+inline typename Scaling<Scalar,Dim>::TransformType
+Scaling<Scalar,Dim>::operator* (const TransformType& t) const
+{
+ TransformType res = t;
+ res.prescale(m_coeffs);
+ return res;
+}
+
+#endif // EIGEN_SCALING_H