WaveClipUIUtilities.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  @file WaveClipUIUtilities.cpp
 
  Paul Licameli split from WaveClip.cpp
 
**********************************************************************/
 
#include "WaveClipUIUtilities.h"
 
#include "PitchAndSpeedDialog.h"
#include "ProjectHistory.h"
#include "SampleCount.h"
#include "UndoManager.h"
#include "ViewInfo.h"
#include "WaveClip.h"
#include <algorithm>
#include <cassert>
#include <cmath>
 
void WaveClipUIUtilities::findCorrection(
   const std::vector<sampleCount>& oldWhere, size_t oldLen, size_t newLen,
   double t0, double sampleRate, double stretchRatio, double samplesPerPixel,
   int& oldX0, double& correction)
{
   // Mitigate the accumulation of location errors
   // in copies of copies of ... of caches.
   // Look at the loop that populates "where" below to understand this.
 
   // Find the sample position that is the origin in the old cache.
   const double oldWhere0 = oldWhere[1].as_double() - samplesPerPixel;
   const double oldWhereLast = oldWhere0 + oldLen * samplesPerPixel;
   // Find the length in samples of the old cache.
   const double denom = oldWhereLast - oldWhere0;
 
   // What sample would go in where[0] with no correction?
   const double guessWhere0 = t0 * sampleRate / stretchRatio;
 
   if ( // Skip if old and NEW are disjoint:
      oldWhereLast <= guessWhere0 ||
      guessWhere0 + newLen * samplesPerPixel <= oldWhere0 ||
      // Skip unless denom rounds off to at least 1.
      denom < 0.5)
   {
      // The computation of oldX0 in the other branch
      // may underflow and the assertion would be violated.
      oldX0 = oldLen;
      correction = 0.0;
   }
   else
   {
      // What integer position in the old cache array does that map to?
      // (even if it is out of bounds)
      oldX0 = floor(0.5 + oldLen * (guessWhere0 - oldWhere0) / denom);
      // What sample count would the old cache have put there?
      const double where0 = oldWhere0 + double(oldX0) * samplesPerPixel;
      // What correction is needed to align the NEW cache with the old?
      const double correction0 = where0 - guessWhere0;
      correction = std::clamp(correction0, -samplesPerPixel, samplesPerPixel);
      assert(correction == correction0);
   }
}
 
void WaveClipUIUtilities::fillWhere(
   std::vector<sampleCount>& where, size_t len, bool addBias, double correction,
   double t0, double sampleRate, double stretchRatio, double samplesPerPixel)
{
   // Be careful to make the first value non-negative
   const auto bias = addBias ? .5 : 0.;
   const double w0 = 0.5 + correction + bias + t0 * sampleRate / stretchRatio;
   where[0] = sampleCount(std::max(0.0, floor(w0)));
   for (decltype(len) x = 1; x < len + 1; x++)
      where[x] = sampleCount(floor(w0 + double(x) * samplesPerPixel));
}
 
std::vector<CommonTrackPanelCell::MenuItem>
WaveClipUIUtilities::GetWaveClipMenuItems()
{
   return {
      { L"Cut", XO("Cut") },
      { L"Copy", XO("Copy") },
      { L"Paste", XO("Paste") },
      {},
      { L"Split", XO("Split Clip") },
      { L"Join", XO("Join Clips") },
      { L"TrackMute", XO("Mute/Unmute Track") },
      {},
      { L"RenameClip", XO("Rename Clip...") },
      { L"ChangePitchAndSpeed", XO("Pitch and Speed...") },
      { L"RenderPitchAndSpeed", XO("Render Pitch and Speed") },
   };
   ;
}
 
void WaveClipUIUtilities::PushClipSpeedChangedUndoState(
   AudacityProject& project, double speedInPercent)
{
   ProjectHistory::Get(project).PushState(
      /* i18n-hint: This is about changing the clip playback speed, speed is in
         percent */
      XO("Changed Clip Speed to %.01f%%").Format(speedInPercent),
      /* i18n-hint: This is about changing the clip playback speed, speed is in
         percent */
      XO("Changed Speed to %.01f%%").Format(speedInPercent),
      UndoPush::CONSOLIDATE);
}
 
void WaveClipUIUtilities::SelectClip(
   AudacityProject& project, const WaveTrack::Interval& clip)
{
   auto& viewInfo = ViewInfo::Get(project);
   viewInfo.selectedRegion.setTimes(
      clip.GetPlayStartTime(), clip.GetPlayEndTime());
}