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livetrax/gtk2_ardour/tempo_lines.cc

127 lines
3.0 KiB
C++

/*
Copyright (C) 2002-2007 Paul Davis
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "canvas/line.h"
#include "canvas/canvas.h"
#include "canvas/debug.h"
#include "tempo_lines.h"
#include "ardour_ui.h"
using namespace std;
TempoLines::TempoLines (ArdourCanvas::Canvas& canvas, ArdourCanvas::Group* group, double h)
: _canvas (canvas)
, _group (group)
, _height (h)
{
}
void
TempoLines::tempo_map_changed()
{
/* remove all lines from the group, put them in the cache (to avoid
* unnecessary object destruction+construction later), and clear _lines
*/
_group->clear ();
_cache.insert (_cache.end(), _lines.begin(), _lines.end());
_lines.clear ();
}
void
TempoLines::show ()
{
_group->show ();
}
void
TempoLines::hide ()
{
_group->hide ();
}
void
TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
const ARDOUR::TempoMap::BBTPointList::const_iterator& end,
double samples_per_pixel)
{
ARDOUR::TempoMap::BBTPointList::const_iterator i;
ArdourCanvas::Rect const visible = _canvas.visible_area ();
double beat_density;
uint32_t beats = 0;
uint32_t bars = 0;
uint32_t color;
/* get the first bar spacing */
i = end;
i--;
bars = (*i).bar - (*begin).bar;
beats = distance (begin, end) - bars;
beat_density = (beats * 10.0f) / visible.width ();
if (beat_density > 4.0f) {
/* if the lines are too close together, they become useless */
tempo_map_changed();
return;
}
tempo_map_changed ();
for (i = begin; i != end; ++i) {
if ((*i).is_bar()) {
color = ARDOUR_UI::config()->get_canvasvar_MeasureLineBar();
} else {
if (beat_density > 2.0) {
continue; /* only draw beat lines if the gaps between beats are large. */
}
color = ARDOUR_UI::config()->get_canvasvar_MeasureLineBeat();
}
ArdourCanvas::Coord xpos = rint(((framepos_t)(*i).frame) / (double)samples_per_pixel);
ArdourCanvas::Line* line;
if (!_cache.empty()) {
line = _cache.back ();
_cache.pop_back ();
line->reparent (_group);
} else {
line = new ArdourCanvas::Line (_group);
CANVAS_DEBUG_NAME (line, "tempo measure line");
line->set_ignore_events (true);
}
/* move to 0.5 offset to ensure single pixel lines (see Cairo
* FAQ for info on why we do this).
*/
line->set_x0 (xpos + 0.5);
line->set_x1 (xpos + 0.5);
line->set_y0 (0.0);
line->set_y1 (_height);
line->set_outline_color (color);
line->show ();
}
}