Fast sine to fill array (sin/cos pair), C++ (vc++)

Fast sine to fill array (sin/cos pair)

//Microsoft (R) C/C++ Optimizing Compiler Version 19.00.23506 for x86

#include <iostream>
#include <cmath>
#include <algorithm>

template<typename T> struct SineIterator
{
  SineIterator(T amplitude, T phi0, T dphi):
    sinState(amplitude*sin(phi0)),
    cosState(amplitude*cos(phi0)),
    dSin(amplitude*sin(dphi) * 1.0000001),
    dCos(amplitude*cos(dphi) * 1.0000001) {}
  
  T Next()
  {
    const T newSin = sinState * dCos + cosState * dSin;
    cosState = std::min<T>(cosState * dCos - sinState * dSin, 1);
    sinState = std::min<T>(newSin, 1);
    return sinState;
  }

private:
  T sinState, cosState;
  const T dSin, dCos;
};

int main()
{
    std::cout << "FLOAT" << std::endl << "---------------------------------------------------------------------" << std::endl;
    SineIterator<float> sr1(1, 0, 3.1415926 / 100);
    for(int j=0; j<100; j++)
    {
        auto prec = sin(3.1415926 / 100 * (j*23456 + 1));
        auto approx = sr1.Next();
        std::cout << approx-prec << " / " << approx << " / " << prec << std::endl;
        for(int i=0; i<23455; i++)
            sr1.Next();
    }
    
    std::cout << std::endl;
    std::cout << "DOUBLE" << std::endl << "---------------------------------------------------------------------" << std::endl;
    SineIterator<double> sr2(1, 0, 3.1415926 / 100);
    for(int j=0; j<100; j++)
    {
        auto prec = sin(3.1415926 / 100 * (j*23456 + 1));
        auto approx = sr2.Next();
        std::cout << approx-prec << " / " << approx << " / " << prec << std::endl;
        for(int i=0; i<23455; i++)
            sr2.Next();
    }
}


run \| edit \| history \| help	0

λ

                                      .NET NoSQL database for rapid development