libs/ardour/quantize.cc

   1 /*
   2     Copyright (C) 2004 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19 #include <cmath>
  20
  21 #include "pbd/basename.h"
  22
  23 #include "ardour/quantize.h"
  24 #include "ardour/midi_model.h"
  25
  26 #include "i18n.h"
  27
  28 using namespace std;
  29 using namespace PBD;
  30 using namespace ARDOUR;
  31
  32 /** Quantize notes
  33  *
  34  * grid parameters are the quantize value in beats, ie 1.0 = quantize to beats,
  35  * 0.25 = quantize to beats/4, etc.
  36  */
  37
  38 Quantize::Quantize (bool snap_start, bool snap_end,
  39                     double start_grid, double end_grid,
  40                     float strength, float swing, float threshold)
  41         : _snap_start (snap_start)
  42         , _snap_end (snap_end)
  43         , _start_grid(start_grid)
  44         , _end_grid(end_grid)
  45         , _strength (strength/100.0)
  46         , _swing (swing/100.0)
  47         , _threshold (threshold)
  48 {
  49 }
  50
  51 Quantize::~Quantize ()
  52 {
  53 }
  54
  55 Command*
  56 Quantize::operator () (boost::shared_ptr<MidiModel> model,
  57                        Evoral::Beats position,
  58                        std::vector<Evoral::Sequence<Evoral::Beats>::Notes>& seqs)
  59 {
  60         /* TODO: Rewrite this to be precise with fixed point? */
  61
  62         /* Calculate offset from start of model to next closest quantize step,
  63            to quantize relative to actual session beats (etc.) rather than from the
  64            start of the model.
  65         */
  66         const double round_pos = round(position.to_double() / _start_grid) * _start_grid;
  67         const double offset    = round_pos - position.to_double();
  68
  69         bool even;
  70         MidiModel::NoteDiffCommand* cmd = new MidiModel::NoteDiffCommand (model, "quantize");
  71
  72         for (std::vector<Evoral::Sequence<Evoral::Beats>::Notes>::iterator s = seqs.begin(); s != seqs.end(); ++s) {
  73
  74                 even = false;
  75
  76                 /* TODO 'swing' probably requires a 2nd iteration:
  77                  * first quantize notes to the grid, then apply beat shift
  78                  */
  79                 for (Evoral::Sequence<MidiModel::TimeType>::Notes::iterator i = (*s).begin(); i != (*s).end(); ++i) {
  80
  81                         double new_start = round (((*i)->time().to_double() - offset) / _start_grid) * _start_grid + offset;
  82                         double new_end = round (((*i)->end_time().to_double() - offset) / _end_grid) * _end_grid + offset;
  83
  84                         if (_swing > 0.0 && !even) {
  85
  86                                 double next_grid = new_start + _start_grid;
  87
  88                                 /* find a spot 2/3 (* swing factor) of the way between the grid point
  89                                    we would put this note at, and the nominal position of the next note.
  90                                 */
  91
  92                                 new_start = new_start + (2.0/3.0 * _swing * (next_grid - new_start));
  93                                 new_end = new_end + (2.0/3.0 * _swing * (next_grid - new_start));
  94
  95                         } else if (_swing < 0.0 && !even) {
  96
  97                                 double prev_grid = new_start - _start_grid;
  98
  99                                 /* find a spot 2/3 (* swing factor) of the way between the grid point
 100                                    we would put this note at, and the nominal position of the previous note.
 101                                 */
 102
 103                                 new_start = new_start - (2.0/3.0 * _swing * (new_start - prev_grid));
 104                                 new_end = new_end - (2.0/3.0 * _swing * (new_start - prev_grid));
 105
 106                         }
 107
 108                         double delta = new_start - (*i)->time().to_double();
 109
 110                         if (fabs (delta) >= _threshold) {
 111                                 if (_snap_start) {
 112                                         delta *= _strength;
 113                                         cmd->change ((*i), MidiModel::NoteDiffCommand::StartTime,
 114                                                      (*i)->time() + delta);
 115                                 }
 116                         }
 117
 118                         if (_snap_end) {
 119                                 delta = new_end - (*i)->end_time().to_double();
 120
 121                                 if (fabs (delta) >= _threshold) {
 122                                         Evoral::Beats new_dur(new_end - new_start);
 123
 124                                         if (!new_dur) {
 125                                                 new_dur = Evoral::Beats(_end_grid);
 126                                         }
 127
 128                                         cmd->change ((*i), MidiModel::NoteDiffCommand::Length, new_dur);
 129                                 }
 130                         }
 131
 132                         even = !even;
 133                 }
 134         }
 135
 136         return cmd;
 137 }