BeatsFormat.cpp

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  BeatsFormat.cpp
 
  Michael Papadopoulos
 
**********************************************************************/
 
#include "BeatsFormat.h"
#include "ProjectTimeSignature.h"
 
#include <cassert>
 
void BeatsFormat::SetTickSizes(
   double units, double& major, double& minor, double &minorMinor,
   int& mDigits
) const
{
   const_cast<BeatsFormat*>(this)->UpdateSubdivision(units);
 
   major = mTicks.major.duration;
   minor = mTicks.minor.duration;
   minorMinor = mTicks.minorMinor.duration;
 
   mDigits = 0;
}
 
void BeatsFormat::SetLabelString(
   wxString& s, double d, double units, double minor, int mDigits, TickType tickType
) const
{
   if (d < 0) {
      return;
   }
 
   const auto lower = static_cast<double>(mTimeSigLower);
   double val = (mBpm * (lower / 4) * d) / (60 * mTimeSigUpper);
   double beatApprox = (val - floor(val)) * mTimeSigUpper + 1;
   int beat = round(beatApprox);
 
   // Don't add decimal if it's a major tick or is on the beat
   // Segment by distance with units
   if (units < .4 * (60 / mBpm)* (4 / lower))
   {
      if (tickType == RulerFormat::t_major) {
         s.Printf(wxT("%d"), (int)round(val + 1));
      }
      else if (tickType == RulerFormat::t_minor && abs(beat - beatApprox) < 1.0e-5f) {
         s.Printf(wxT("%d.%d"), (int)floor(val + 1), (int)beat);
      }
   }
   else if (units < .8 * (60 / mBpm) * (4 / lower))
   {
      if (tickType == RulerFormat::t_major) {
         s.Printf(wxT("%d"), (int)round(val + 1));
      }
      else if (tickType == RulerFormat::t_minor && beat != 1) {
         s.Printf(wxT("%d.%d"), (int)floor(val + 1), (int)beat);
      }
   }
   else {
      if (tickType == RulerFormat::t_major) {
         s.Printf(wxT("%d"), (int)round(val + 1));
      }
   }
}
 
void BeatsFormat::SetData(double bpm, int timeSigUpper, int timeSigLower)
{
   // Check preconditions
   assert(bpm > 0);
   assert(timeSigUpper > 0);
   assert(timeSigLower > 1);
   assert((timeSigLower & (timeSigLower - 1)) == 0);
 
   if (!(mBpm > 0 && mTimeSigUpper > 1 && mTimeSigLower > 1))
      return;
 
   if (mTimeSigLower & (mTimeSigLower - 1))
      return;
 
   mBpm = bpm;
   mTimeSigUpper = timeSigUpper;
   mTimeSigLower = timeSigLower;
}
 
void BeatsFormat::UpdateSubdivision(double units)
{
   Ticks ticks;
 
   const auto lower = static_cast<double>(mTimeSigLower);
   if (units < .025 * (60 / mBpm) * (4 / lower))
   {
      // measures
      ticks.major = { mTimeSigUpper, mTimeSigLower,
                      (60 * mTimeSigUpper) / (mBpm * (lower / 4)) };
      // thirtysecondth notes (label every quarter note)
      ticks.minor = { 1, 32, 60 / (mBpm * (lower * 2)) };
      // hundredtwentyeighth notes
      ticks.minorMinor = { 1, 128, 60 / (mBpm * (lower * 8)) };
   }
   else if (units < .05 * (60 / mBpm) * (4 / lower))
   {
      // measures
      ticks.major = { mTimeSigUpper, mTimeSigLower,
                      (60 * mTimeSigUpper) / (mBpm * (lower / 4)) };
      // sixteenth notes (label every quarter note)
      ticks.minor = { 1, 16, 60 / (mBpm * (lower)) };
      // sixtyfourth notes
      ticks.minorMinor = { 1, 64, 60 / (mBpm * (lower * 4)) };
   }
   else if (units < .1 * (60 / mBpm) * (4 / lower))
   {
      // measures
      ticks.major = { mTimeSigUpper, mTimeSigLower,
                      (60 * mTimeSigUpper) / (mBpm * (lower / 4)) };
      // eigth notes (label every quarter note)
      ticks.minor = { 1, 8, 60 / (mBpm * (lower / 2)) };
      // thirtysecondth notes
      ticks.minorMinor = { 1, 32, 60 / (mBpm * (lower * 2)) };
   }
   else if (units < .4 * (60 / mBpm) * (4 / lower))
   {
      // measures
      ticks.major = { mTimeSigUpper, mTimeSigLower,
                      (60 * mTimeSigUpper) / (mBpm * (lower / 4)) };
      // eigth notes (label every quarter note)
      ticks.minor = { 1, 8, 60 / (mBpm * (lower / 2)) };
      // sixteenth notes
      ticks.minorMinor = { 1, 16, 60 / (mBpm * (lower)) };
   }
   else if (units < .8 * (60 / mBpm) * (4 / lower))
   {
      // measures
      ticks.major = { mTimeSigUpper, mTimeSigLower,
                      (60 * mTimeSigUpper) / (mBpm * (lower / 4)) };
      // quarter notes
      ticks.minor = { 1, 4, 60 / (mBpm * (lower / 4)) };
      // sixteenth notes
      ticks.minorMinor = { 1, 16, 60 / (mBpm * (lower)) };
   }
   else if (units < 4 * (60 / mBpm) * (4 / lower))
   {
      // measures
      ticks.major = { mTimeSigUpper, mTimeSigLower,
                      (60 * mTimeSigUpper) / (mBpm * (lower / 4)) };
      // quarter notes
      ticks.minorMinor = { 1, 4, 60 / (mBpm * (lower / 4)) };
   }
   else if (units < 8 * (60 / mBpm) * (4 / lower))
   {
      // four-measures
      ticks.major = { 4 * mTimeSigUpper, mTimeSigLower,
                      (60 * mTimeSigUpper) / (mBpm * (lower / 16)) };
      // measures
      ticks.minor = { 4, mTimeSigLower, 60 / (mBpm * (lower / 16)) };
      // half measures
      ticks.minorMinor = { 2, mTimeSigLower, 60 / (mBpm * (lower / 8)) };
   }
   else
   {
      int factor = pow(
         2, std::floor(
               log2(std::ceil(units) * (mBpm / 60) * (mTimeSigLower / 4))) -
               2);
      ticks.major = { factor * 4 * mTimeSigUpper, mTimeSigLower,
                (60 * mTimeSigUpper) / (mBpm * (lower / (16 * factor))) };
      ticks.minorMinor = { factor * 2, mTimeSigLower,
                           60 / (mBpm * (lower / (8 * factor))) };
   }
 
   mTicks = ticks;
}
 
const BeatsFormat::Ticks& BeatsFormat::GetSubdivision() const
{
   return mTicks;
}
 
BeatsFormat::BeatsFormat(const ProjectTimeSignature& sig)
{
   SetData(
      sig.GetTempo(), sig.GetUpperTimeSignature(), sig.GetLowerTimeSignature());
}
 
BeatsFormat::~BeatsFormat() = default;