* start of the Geometry module with a cross product and quaternion expressions

(haven't tried them yet) * applied the meta selector rule to MatrixBase::swap()
2026-04-10 11:34:33 +08:00 · 2008-06-02 22:58:36 +00:00
parent 75de41a00b
commit 366971bea4
7 changed files with 480 additions and 26 deletions
--- a/Eigen/src/Geometry/Cross.h
+++ b/Eigen/src/Geometry/Cross.h
@@ -0,0 +1,102 @@
+// 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_CROSS_H
+#define EIGEN_CROSS_H
+
+/** \class Cross
+  *
+  * \brief Expression of the cross product of two vectors
+  *
+  * \param Lhs the type of the left-hand side
+  * \param Rhs the type of the right-hand side
+  *
+  * This class represents an expression of the cross product of two 3D vectors.
+  * It is the return type of MatrixBase::cross(), and most
+  * of the time this is the only way it is used.
+  */
+template<typename Lhs, typename Rhs>
+struct ei_traits<Cross<Lhs, Rhs> >
+{
+  typedef typename Lhs::Scalar Scalar;
+  typedef typename ei_nested<Lhs,2>::type LhsNested;
+  typedef typename ei_nested<Rhs,2>::type RhsNested;
+  typedef typename ei_unref<LhsNested>::type _LhsNested;
+  typedef typename ei_unref<RhsNested>::type _RhsNested;
+  enum {
+    RowsAtCompileTime = 3,
+    ColsAtCompileTime = 1,
+    MaxRowsAtCompileTime = 3,
+    MaxColsAtCompileTime = 1,
+    Flags = ((_RhsNested::Flags | _LhsNested::Flags) & HereditaryBits)
+          | EvalBeforeAssigningBit,
+    CoeffReadCost = NumTraits<Scalar>::AddCost + 2 * NumTraits<Scalar>::MulCost
+  };
+};
+
+template<typename Lhs, typename Rhs> class Cross : ei_no_assignment_operator,
+    public MatrixBase<Cross<Lhs, Rhs> >
+{
+  public:
+
+    EIGEN_GENERIC_PUBLIC_INTERFACE(Cross)
+    typedef typename ei_traits<Cross>::LhsNested LhsNested;
+    typedef typename ei_traits<Cross>::RhsNested RhsNested;
+
+    Cross(const Lhs& lhs, const Rhs& rhs)
+      : m_lhs(lhs), m_rhs(rhs)
+    {
+      assert(lhs.isVector());
+      assert(rhs.isVector());
+      assert(lhs.size() == 3 && rhs.size() == 3);
+    }
+
+  private:
+
+    int _rows() const { return 3; }
+    int _cols() const { return 1; }
+
+    Scalar _coeff(int i, int) const
+    {
+      return m_lhs[(i+1)%3]*m_rhs[(i+2)%3] - m_lhs[(i+2)%3]*m_rhs[(i+1)%3];
+    }
+
+  protected:
+    const LhsNested m_lhs;
+    const RhsNested m_rhs;
+};
+
+/** \returns an expression of the cross product of \c *this and \a other
+  *
+  * \sa class Cross
+  */
+template<typename Derived>
+template<typename OtherDerived>
+const Cross<Derived,OtherDerived>
+MatrixBase<Derived>::cross(const MatrixBase<OtherDerived>& other) const
+{
+    return Cross<Derived,OtherDerived>(derived(),other.derived());
+}
+
+#endif // EIGEN_CROSS_H