gtk2_ardour/tempo_lines.cc

   1 /*
   2     Copyright (C) 2002-2007 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
  20 #include "canvas/line.h"
  21 #include "canvas/canvas.h"
  22 #include "canvas/debug.h"
  23 #include "tempo_lines.h"
  24 #include "ardour_ui.h"
  25
  26 using namespace std;
  27
  28 #define MAX_CACHED_LINES 128
  29
  30 TempoLines::TempoLines (ArdourCanvas::GtkCanvasViewport& canvas_viewport, ArdourCanvas::Group* group, double screen_height)
  31         : _canvas_viewport (canvas_viewport)
  32         , _group(group)
  33         , _clean_left(DBL_MAX)
  34         , _clean_right(0.0)
  35         , _height(screen_height)
  36 {
  37 }
  38
  39 void
  40 TempoLines::tempo_map_changed()
  41 {
  42         _clean_left = DBL_MAX;
  43         _clean_right = 0.0;
  44
  45         double_t d = 1.0;
  46         // TODO: Dirty/slow, but 'needed' for zoom :(
  47         for (Lines::iterator i = _lines.begin(); i != _lines.end(); d += 1.0) {
  48                 Lines::iterator next = i;
  49                 ++next;
  50                 i->second->set_x0 (-d);
  51                 i->second->set_x1 (-d);
  52                 ArdourCanvas::Line* f = i->second;
  53                 _lines.erase(i);
  54                 _lines.insert(make_pair(- d, f));
  55                 i = next;
  56         }
  57 }
  58
  59 void
  60 TempoLines::show ()
  61 {
  62         for (Lines::iterator i = _lines.begin(); i != _lines.end(); ++i) {
  63                 i->second->show();
  64         }
  65 }
  66
  67 void
  68 TempoLines::hide ()
  69 {
  70         for (Lines::iterator i = _lines.begin(); i != _lines.end(); ++i) {
  71                 i->second->hide();
  72         }
  73 }
  74
  75 void
  76 TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
  77                   const ARDOUR::TempoMap::BBTPointList::const_iterator& end,
  78                   double frames_per_pixel)
  79 {
  80         ARDOUR::TempoMap::BBTPointList::const_iterator i;
  81         ArdourCanvas::Line *line = 0;
  82         gdouble xpos;
  83         double  beat_density;
  84
  85         uint32_t beats = 0;
  86         uint32_t bars = 0;
  87         uint32_t color;
  88
  89         const size_t needed = distance (begin, end);
  90
  91         ArdourCanvas::Rect const visible = _canvas_viewport.visible_area ();
  92
  93         /* get the first bar spacing */
  94
  95         i = end;
  96         i--;
  97         bars = (*i).bar - (*begin).bar;
  98         beats = distance (begin, end) - bars;
  99
 100         beat_density = (beats * 10.0f) / visible.width ();
 101
 102         if (beat_density > 4.0f) {
 103                 /* if the lines are too close together, they become useless */
 104                 tempo_map_changed();
 105                 return;
 106         }
 107
 108         xpos = rint(((framepos_t)(*i).frame) / (double)frames_per_pixel);
 109         const double needed_right = xpos;
 110
 111         i = begin;
 112
 113         xpos = rint(((framepos_t)(*i).frame) / (double)frames_per_pixel);
 114         const double needed_left = xpos;
 115
 116         Lines::iterator left = _lines.lower_bound(xpos); // first line >= xpos
 117
 118         bool exhausted = (left == _lines.end());
 119         Lines::iterator li = left;
 120         if (li != _lines.end())
 121                 line = li->second;
 122
 123         // Tempo map hasn't changed and we're entirely within a clean
 124         // range, don't need to do anything.  Yay.
 125         if (needed_left >= _clean_left && needed_right <= _clean_right) {
 126                 // cout << endl << "*** LINE CACHE PERFECT HIT" << endl;
 127                 return;
 128         }
 129
 130         //cout << endl << "*** LINE CACHE MISS" << endl;
 131
 132         bool inserted_last_time = true;
 133         bool invalidated = false;
 134
 135         for (i = begin; i != end; ++i) {
 136
 137                 if ((*i).is_bar()) {
 138                         color = ARDOUR_UI::config()->canvasvar_MeasureLineBar.get();
 139                 } else {
 140                         if (beat_density > 2.0) {
 141                                 continue; /* only draw beat lines if the gaps between beats are large. */
 142                         }
 143                         color = ARDOUR_UI::config()->canvasvar_MeasureLineBeat.get();
 144                 }
 145
 146                 xpos = rint(((framepos_t)(*i).frame) / (double)frames_per_pixel);
 147
 148                 li = _lines.lower_bound(xpos); // first line >= xpos
 149
 150                 line = (li != _lines.end()) ? li->second : 0;
 151                 assert(!line || line->x0() == li->first);
 152
 153                 Lines::iterator next = li;
 154                 if (next != _lines.end())
 155                         ++next;
 156
 157                 exhausted = (next == _lines.end());
 158
 159                 // Hooray, line is perfect
 160                 if (line && line->x0() == xpos) {
 161                         if (li != _lines.end())
 162                                 ++li;
 163
 164                         line->set_outline_color (color);
 165                         inserted_last_time = false; // don't search next time
 166                         // Use existing line, moving if necessary
 167                 } else if (!exhausted) {
 168                         Lines::iterator steal = _lines.end();
 169                         --steal;
 170
 171                         // Steal from the right
 172                         if (left->first > needed_left && li != steal && steal->first > needed_right) {
 173                                 //cout << "*** STEALING FROM RIGHT" << endl;
 174                                 double const x = steal->first;
 175                                 line = steal->second;
 176                                 _lines.erase(steal);
 177                                 line->set_x0 (xpos);
 178                                 line->set_x1 (xpos);
 179                                 line->set_outline_color (color);
 180                                 _lines.insert(make_pair(xpos, line));
 181                                 inserted_last_time = true; // search next time
 182                                 invalidated = true;
 183
 184                                 // Shift clean range left
 185                                 _clean_left = min(_clean_left, xpos);
 186                                 _clean_right = min(_clean_right, x);
 187
 188                                 // Move this line to where we need it
 189                         } else {
 190                                 Lines::iterator existing = _lines.find(xpos);
 191                                 if (existing != _lines.end()) {
 192                                         //cout << "*** EXISTING LINE" << endl;
 193                                         li = existing;
 194                                         li->second->set_outline_color (color);
 195                                         inserted_last_time = false; // don't search next time
 196                                 } else {
 197                                         //cout << "*** MOVING LINE" << endl;
 198                                         const double x1 = line->x0();
 199                                         const bool was_clean = x1 >= _clean_left && x1 <= _clean_right;
 200                                         invalidated = invalidated || was_clean;
 201                                         // Invalidate clean portion (XXX: too harsh?)
 202                                         _clean_left  = needed_left;
 203                                         _clean_right = needed_right;
 204                                         _lines.erase(li);
 205                                         line->set_outline_color (color);
 206                                         line->set_x0 (xpos);
 207                                         line->set_x1 (xpos);
 208                                         _lines.insert(make_pair(xpos, line));
 209                                         inserted_last_time = true; // search next time
 210                                 }
 211                         }
 212
 213                         // Create a new line
 214                 } else if (_lines.size() < needed || _lines.size() < MAX_CACHED_LINES) {
 215                         //cout << "*** CREATING LINE" << endl;
 216                         /* if we already have a line there ... don't sweat it */
 217                         if (_lines.find (xpos) == _lines.end()) {
 218                                 line = new ArdourCanvas::Line (_group);
 219                                 line->set_x0 (xpos);
 220                                 line->set_x1 (xpos);
 221                                 line->set_y0 (0.0);
 222                                 line->set_y1 (_height);
 223                                 line->set_outline_color (color);
 224                                 _lines.insert(make_pair(xpos, line));
 225                                 inserted_last_time = true;
 226                         }
 227
 228                         // Steal from the left
 229                 } else {
 230                         //cout << "*** STEALING FROM LEFT" << endl;
 231                         if (_lines.find (xpos) == _lines.end()) {
 232                                 Lines::iterator steal = _lines.begin();
 233                                 double const x = steal->first;
 234                                 line = steal->second;
 235                                 _lines.erase(steal);
 236                                 line->set_outline_color (color);
 237                                 line->set_x0 (xpos);
 238                                 line->set_x1 (xpos);
 239                                 _lines.insert(make_pair(xpos, line));
 240                                 inserted_last_time = true; // search next time
 241                                 invalidated = true;
 242
 243                                 // Shift clean range right
 244                                 _clean_left = max(_clean_left, x);
 245                                 _clean_right = max(_clean_right, xpos);
 246                         }
 247                 }
 248         }
 249
 250         // Extend range to what we've 'fixed'
 251         if (!invalidated) {
 252                 _clean_left  = min(_clean_left, needed_left);
 253                 _clean_right = max(_clean_right, needed_right);
 254         }
 255 }
 256