CxxUtils::sincos Struct Reference

Helper to simultaneously calculate sin and cos of the same angle. More...

#include <sincos.h>

Collaboration diagram for CxxUtils::sincos:

Public Member Functions
	sincos (double x)
	Calculate sine and cosine of x. More...
double	apply (double a, double b) const
	\(a\sin(x) + b\cos(x)\) More...
double	apply2 (double a, double b, double c) const
	\(a\sin^2(x) + b\sin(x)\cos(x) + c\cos^2(x)\) More...

Public Attributes
double	sn
	\(\sin(x)\) More...
double	cs
	\(\cos(x)\) More...

Detailed Description

Helper to simultaneously calculate sin and cos of the same angle.

Instantiate an instance of this object, passing the angle to the constructor. The sin and cos are then available as the sn and cs members. In addition, the apply() method may be used to calculate a*sin(x) + b*cos(x).

Implementation notes:

This used to inline the fsincos x87 instruction. However, with current compilers on x86_64, it's faster to just use sincos(). We keep this around since sincos() is a GNU extension and we don't want to have to put #ifdefs everywhere we use this.

Definition at line 38 of file sincos.h.

Constructor & Destructor Documentation

sincos()

CxxUtils::sincos::sincos ( double  x )

inline

Calculate sine and cosine of x.

Definition at line 41 of file sincos.h.

  { ::sincos(x, &sn, &cs); }
#else
  // Generic version.
  : sn (std::sin (x)), cs (std::cos (x)) {}

Member Function Documentation

apply()

double CxxUtils::sincos::apply ( double  a, double  b  ) const

inline

\(a\sin(x) + b\cos(x)\)

Definition at line 57 of file sincos.h.

{ return a*sn + b*cs; }

apply2()

double CxxUtils::sincos::apply2 ( double  a, double  b, double  c  ) const

inline

\(a\sin^2(x) + b\sin(x)\cos(x) + c\cos^2(x)\)

Definition at line 60 of file sincos.h.

  { return a*sn*sn + b*sn*cs + c*cs*cs; }

Member Data Documentation

cs

double CxxUtils::sincos::cs

\(\cos(x)\)

Definition at line 54 of file sincos.h.

sn

double CxxUtils::sincos::sn

\(\sin(x)\)

Definition at line 51 of file sincos.h.

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The documentation for this struct was generated from the following file:

• sincos.h