stella/src/common/audio/HighPass.cxx

37 lines
1.2 KiB
C++

//============================================================================
//
// SSSS tt lll lll
// SS SS tt ll ll
// SS tttttt eeee ll ll aaaa
// SSSS tt ee ee ll ll aa
// SS tt eeeeee ll ll aaaaa -- "An Atari 2600 VCS Emulator"
// SS SS tt ee ll ll aa aa
// SSSS ttt eeeee llll llll aaaaa
//
// Copyright (c) 1995-2022 by Bradford W. Mott, Stephen Anthony
// and the Stella Team
//
// See the file "License.txt" for information on usage and redistribution of
// this file, and for a DISCLAIMER OF ALL WARRANTIES.
//============================================================================
#include "bspf.hxx"
#include "HighPass.hxx"
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
HighPass::HighPass(float cutOffFrequency, float frequency)
: myAlpha{1.F / (1.F + 2.F*BSPF::PI_f*cutOffFrequency/frequency)}
{
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
float HighPass::apply(float valueIn)
{
float valueOut = myAlpha * (myLastValueOut + valueIn - myLastValueIn);
myLastValueIn = valueIn;
myLastValueOut = valueOut;
return valueOut;
}