Fade.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  Fade.cpp
 
  Dominic Mazzoni
 
**********************************************************************/
 
#include "Fade.h"
 
Fade::Fade(bool fadeIn)
{
   mFadeIn = fadeIn;
}
 
Fade::~Fade()
{
}
 
// EffectDefinitionInterface implementation
 
EffectType Fade::GetType() const
{
   return EffectTypeProcess;
}
 
bool Fade::IsInteractive() const
{
   return false;
}
 
unsigned Fade::GetAudioInCount() const
{
   return 1;
}
 
unsigned Fade::GetAudioOutCount() const
{
   return 1;
}
 
bool Fade::ProcessInitialize(EffectSettings&, double, ChannelNames chanMap)
{
   mSample = 0;
   return true;
}
 
size_t Fade::ProcessBlock(
   EffectSettings&, const float* const* inBlock, float* const* outBlock,
   size_t blockLen)
{
   const float* ibuf = inBlock[0];
   float* obuf = outBlock[0];
 
   if (mFadeIn)
   {
      for (decltype(blockLen) i = 0; i < blockLen; i++)
      {
         obuf[i] = (ibuf[i] * (mSample++).as_float()) / mSampleCnt.as_float();
      }
   }
   else
   {
      for (decltype(blockLen) i = 0; i < blockLen; i++)
      {
         obuf[i] = (ibuf[i] * (mSampleCnt - 1 - mSample++).as_float()) /
                   mSampleCnt.as_float();
      }
   }
 
   return blockLen;
}
 
const ComponentInterfaceSymbol FadeIn::Symbol { XO("Fade In") };
 
FadeIn::FadeIn()
    : Fade { true }
{
}
 
ComponentInterfaceSymbol FadeIn::GetSymbol() const
{
   return Symbol;
}
 
TranslatableString FadeIn::GetDescription() const
{
   return XO("Applies a linear fade-in to the selected audio");
}
 
const ComponentInterfaceSymbol FadeOut::Symbol { XO("Fade Out") };
 
FadeOut::FadeOut()
    : Fade { false }
{
}
 
ComponentInterfaceSymbol FadeOut::GetSymbol() const
{
   return Symbol;
}
 
TranslatableString FadeOut::GetDescription() const
{
   return XO("Applies a linear fade-out to the selected audio");
}