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 (Session& s, bool snap_start, bool snap_end,
  39                     double start_grid, double end_grid,
  40                     float strength, float swing, float threshold)
  41         : session (s)
  42         , _snap_start (snap_start)
  43         , _snap_end (snap_end)
  44         , _start_grid(start_grid)
  45         , _end_grid(end_grid)
  46         , _strength (strength/100.0)
  47         , _swing (swing/100.0)
  48         , _threshold (threshold)
  49 {
  50 }
  51
  52 Quantize::~Quantize ()
  53 {
  54 }
  55
  56 Command*
  57 Quantize::operator () (boost::shared_ptr<MidiModel> model,
  58                        double position,
  59                        std::vector<Evoral::Sequence<Evoral::MusicalTime>::Notes>& seqs)
  60 {
  61         /* Calculate offset from start of model to next closest quantize step,
  62            to quantize relative to actual session beats (etc.) rather than from the
  63            start of the model.
  64         */
  65         const double round_pos = round(position / _start_grid) * _start_grid;
  66         const double offset    = round_pos - position;
  67
  68         bool even;
  69         MidiModel::NoteDiffCommand* cmd = new MidiModel::NoteDiffCommand (model, "quantize");
  70
  71         for (std::vector<Evoral::Sequence<Evoral::MusicalTime>::Notes>::iterator s = seqs.begin(); s != seqs.end(); ++s) {
  72
  73                 even = false;
  74
  75                 /* TODO 'swing' probably requires a 2nd iteration:
  76                  * first quantize notes to the grid, then apply beat shift
  77                  */
  78                 for (Evoral::Sequence<MidiModel::TimeType>::Notes::iterator i = (*s).begin(); i != (*s).end(); ++i) {
  79
  80                         double new_start = round (((*i)->time() - offset) / _start_grid) * _start_grid + offset;
  81                         double new_end = round (((*i)->end_time() - offset) / _end_grid) * _end_grid + offset;
  82
  83                         if (_swing > 0.0 && !even) {
  84
  85                                 double next_grid = new_start + _start_grid;
  86
  87                                 /* find a spot 2/3 (* swing factor) of the way between the grid point
  88                                    we would put this note at, and the nominal position of the next note.
  89                                 */
  90
  91                                 new_start = new_start + (2.0/3.0 * _swing * (next_grid - new_start));
  92                                 new_end = new_end + (2.0/3.0 * _swing * (next_grid - new_start));
  93
  94                         } else if (_swing < 0.0 && !even) {
  95
  96                                 double prev_grid = new_start - _start_grid;
  97
  98                                 /* find a spot 2/3 (* swing factor) of the way between the grid point
  99                                    we would put this note at, and the nominal position of the previous note.
 100                                 */
 101
 102                                 new_start = new_start - (2.0/3.0 * _swing * (new_start - prev_grid));
 103                                 new_end = new_end - (2.0/3.0 * _swing * (new_start - prev_grid));
 104
 105                         }
 106
 107                         double delta = new_start - (*i)->time();
 108
 109                         if (fabs (delta) >= _threshold) {
 110                                 if (_snap_start) {
 111                                         delta *= _strength;
 112                                         cmd->change ((*i), MidiModel::NoteDiffCommand::StartTime,
 113                                                      (*i)->time() + delta);
 114                                 }
 115                         }
 116
 117                         if (_snap_end) {
 118                                 delta = new_end - (*i)->end_time();
 119
 120                                 if (fabs (delta) >= _threshold) {
 121                                         double new_dur = new_end - new_start;
 122
 123                                         if (new_dur == 0.0) {
 124                                                 new_dur = _end_grid;
 125                                         }
 126
 127                                         cmd->change ((*i), MidiModel::NoteDiffCommand::Length, new_dur);
 128                                 }
 129                         }
 130
 131                         even = !even;
 132                 }
 133         }
 134
 135         return cmd;
 136 }