From 05a49547e155b85ff0a84c2e23ede166ca1ee179 Mon Sep 17 00:00:00 2001
From: Benoit Jacob <jacob.benoit.1@gmail.com>
Date: Wed, 26 Dec 2007 08:30:21 +0000
Subject: [PATCH] in ScalarMultiple, make the factor type independent from the
 matrix scalar type. This is an optimization for complex matrices, allowing to
 do only a real multiplication when a complex multiplication is not needed,
 e.g. in normalized().

---
 Eigen/Core/Dot.h            |  3 ++-
 Eigen/Core/MathFunctions.h  | 17 +++++++++++++++++
 Eigen/Core/MatrixBase.h     |  2 +-
 Eigen/Core/ScalarMultiple.h | 38 ++++++++++++++++++-------------------
 Eigen/Core/Util.h           |  2 +-
 5 files changed, 40 insertions(+), 22 deletions(-)

diff --git a/Eigen/Core/Dot.h b/Eigen/Core/Dot.h
index ff6852af2..32cab5bbb 100644
--- a/Eigen/Core/Dot.h
+++ b/Eigen/Core/Dot.h
@@ -89,7 +89,8 @@ typename NumTraits<Scalar>::Real MatrixBase<Scalar, Derived>::norm() const
 }
 
 template<typename Scalar, typename Derived>
-ScalarMultiple<Derived> MatrixBase<Scalar, Derived>::normalized() const
+const ScalarMultiple<typename NumTraits<Scalar>::Real, Derived>
+MatrixBase<Scalar, Derived>::normalized() const
 {
   return (*this) / norm();
 }
diff --git a/Eigen/Core/MathFunctions.h b/Eigen/Core/MathFunctions.h
index 0647e943f..2cf28e8a7 100644
--- a/Eigen/Core/MathFunctions.h
+++ b/Eigen/Core/MathFunctions.h
@@ -172,4 +172,21 @@ inline bool isApprox(const std::complex<double>& a, const std::complex<double>&
 }
 // isApproxOrLessThan wouldn't make sense for complex numbers
 
+#define EIGEN_MAKE_MORE_OVERLOADED_COMPLEX_OPERATOR_STAR(T,U) \
+inline std::complex<T> operator*(U a, const std::complex<T>& b) \
+{ \
+  return std::complex<T>(static_cast<T>(a)*b.real(), \
+                         static_cast<T>(a)*b.imag()); \
+} \
+inline std::complex<T> operator*(const std::complex<T>& b, U a) \
+{ \
+  return std::complex<T>(static_cast<T>(a)*b.real(), \
+                         static_cast<T>(a)*b.imag()); \
+}
+
+EIGEN_MAKE_MORE_OVERLOADED_COMPLEX_OPERATOR_STAR(int,    float)
+EIGEN_MAKE_MORE_OVERLOADED_COMPLEX_OPERATOR_STAR(int,    double)
+EIGEN_MAKE_MORE_OVERLOADED_COMPLEX_OPERATOR_STAR(float,  double)
+EIGEN_MAKE_MORE_OVERLOADED_COMPLEX_OPERATOR_STAR(double, float)
+
 #endif // EIGEN_MATHFUNCTIONS_H
diff --git a/Eigen/Core/MatrixBase.h b/Eigen/Core/MatrixBase.h
index 4550deabf..c15167291 100644
--- a/Eigen/Core/MatrixBase.h
+++ b/Eigen/Core/MatrixBase.h
@@ -149,7 +149,7 @@ template<typename Scalar, typename Derived> class MatrixBase
     Scalar dot(const OtherDerived& other) const;
     RealScalar norm2() const;
     RealScalar norm()  const;
-    ScalarMultiple<Derived> normalized() const;
+    const ScalarMultiple<RealScalar, Derived> normalized() const;
     
     static Eval<Random<Derived> > random(int rows, int cols);
     static Eval<Random<Derived> > random(int size);
diff --git a/Eigen/Core/ScalarMultiple.h b/Eigen/Core/ScalarMultiple.h
index 95c44fc0f..06c6e295f 100644
--- a/Eigen/Core/ScalarMultiple.h
+++ b/Eigen/Core/ScalarMultiple.h
@@ -26,19 +26,19 @@
 #ifndef EIGEN_SCALARMULTIPLE_H
 #define EIGEN_SCALARMULTIPLE_H
 
-template<typename MatrixType> class ScalarMultiple : NoOperatorEquals,
-  public MatrixBase<typename MatrixType::Scalar, ScalarMultiple<MatrixType> >
+template<typename FactorType, typename MatrixType> class ScalarMultiple : NoOperatorEquals,
+  public MatrixBase<typename MatrixType::Scalar, ScalarMultiple<FactorType, MatrixType> >
 {
   public:
     typedef typename MatrixType::Scalar Scalar;
     typedef typename MatrixType::Ref MatRef;
-    friend class MatrixBase<typename MatrixType::Scalar, ScalarMultiple<MatrixType> >;
+    friend class MatrixBase<Scalar, ScalarMultiple<FactorType, MatrixType> >;
 
-    ScalarMultiple(const MatRef& matrix, Scalar scalar)
-      : m_matrix(matrix), m_scalar(scalar) {}
+    ScalarMultiple(const MatRef& matrix, FactorType factor)
+      : m_matrix(matrix), m_factor(factor) {}
 
     ScalarMultiple(const ScalarMultiple& other)
-      : m_matrix(other.m_matrix), m_scalar(other.m_scalar) {}
+      : m_matrix(other.m_matrix), m_factor(other.m_factor) {}
 
   private:
     static const int _RowsAtCompileTime = MatrixType::RowsAtCompileTime,
@@ -50,35 +50,35 @@ template<typename MatrixType> class ScalarMultiple : NoOperatorEquals,
 
     Scalar _coeff(int row, int col) const
     {
-      return m_matrix.coeff(row, col) * m_scalar;
+      return m_factor * m_matrix.coeff(row, col);
     }
 
   protected:
     const MatRef m_matrix;
-    const Scalar m_scalar;
+    const FactorType m_factor;
 };
 
-#define EIGEN_MAKE_SCALAR_OPS(OtherScalar)                             \
+#define EIGEN_MAKE_SCALAR_OPS(FactorType)                              \
 template<typename Scalar, typename Derived>                            \
-const ScalarMultiple<Derived>                                          \
+const ScalarMultiple<FactorType, Derived>                              \
 operator*(const MatrixBase<Scalar, Derived>& matrix,                   \
-          OtherScalar scalar)                                          \
+          FactorType scalar)                                           \
 {                                                                      \
-  return ScalarMultiple<Derived>(matrix.ref(), scalar);                \
+  return ScalarMultiple<FactorType, Derived>(matrix.ref(), scalar);    \
 }                                                                      \
                                                                        \
 template<typename Scalar, typename Derived>                            \
-const ScalarMultiple<Derived>                                          \
-operator*(OtherScalar scalar,                                          \
+const ScalarMultiple<FactorType, Derived>                              \
+operator*(FactorType scalar,                                           \
           const MatrixBase<Scalar, Derived>& matrix)                   \
 {                                                                      \
-  return ScalarMultiple<Derived>(matrix.ref(), scalar);                \
+  return ScalarMultiple<FactorType, Derived>(matrix.ref(), scalar);    \
 }                                                                      \
                                                                        \
 template<typename Scalar, typename Derived>                            \
-const ScalarMultiple<Derived>                                          \
+const ScalarMultiple<FactorType, Derived>                              \
 operator/(const MatrixBase<Scalar, Derived>& matrix,                   \
-          OtherScalar scalar)                                          \
+          FactorType scalar)                                           \
 {                                                                      \
   assert(NumTraits<Scalar>::HasFloatingPoint);                         \
   return matrix * (static_cast<Scalar>(1) / scalar);                   \
@@ -86,14 +86,14 @@ operator/(const MatrixBase<Scalar, Derived>& matrix,                   \
                                                                        \
 template<typename Scalar, typename Derived>                            \
 Derived &                                                              \
-MatrixBase<Scalar, Derived>::operator*=(const OtherScalar &other)      \
+MatrixBase<Scalar, Derived>::operator*=(const FactorType &other)       \
 {                                                                      \
   return *this = *this * other;                                        \
 }                                                                      \
                                                                        \
 template<typename Scalar, typename Derived>                            \
 Derived &                                                              \
-MatrixBase<Scalar, Derived>::operator/=(const OtherScalar &other)      \
+MatrixBase<Scalar, Derived>::operator/=(const FactorType &other)       \
 {                                                                      \
   return *this = *this / other;                                        \
 }
diff --git a/Eigen/Core/Util.h b/Eigen/Core/Util.h
index c1576af00..0bccc1f75 100644
--- a/Eigen/Core/Util.h
+++ b/Eigen/Core/Util.h
@@ -97,7 +97,7 @@ template<typename MatrixType> class Opposite;
 template<typename Lhs, typename Rhs> class Sum;
 template<typename Lhs, typename Rhs> class Difference;
 template<typename Lhs, typename Rhs> class Product;
-template<typename MatrixType> class ScalarMultiple;
+template<typename FactorType, typename MatrixType> class ScalarMultiple;
 template<typename MatrixType> class Random;
 template<typename MatrixType> class Zero;
 template<typename MatrixType> class Ones;