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livetrax/gtk2_ardour/tempo_lines.cc

149 lines
4.2 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 "pbd/compose.h"
#include "canvas/canvas.h"
#include "canvas/debug.h"
#include "ardour_ui.h"
#include "public_editor.h"
#include "rgb_macros.h"
#include "tempo_lines.h"
using namespace std;
TempoLines::TempoLines (ArdourCanvas::Container* group, double)
: lines (group, ArdourCanvas::LineSet::Vertical)
{
lines.set_extent (ArdourCanvas::COORD_MAX);
}
void
TempoLines::tempo_map_changed()
{
lines.clear ();
}
void
TempoLines::show ()
{
lines.show ();
}
void
TempoLines::hide ()
{
lines.hide ();
}
void
TempoLines::draw_ticks (const ARDOUR::TempoMap::BBTPointList::const_iterator& b,
unsigned divisions,
framecnt_t leftmost_frame,
framecnt_t frame_rate)
{
const double fpb = b->tempo->frames_per_beat(frame_rate);
const uint32_t base = ARDOUR_UI::config()->color_mod("measure line beat", "measure line beat");
for (unsigned l = 1; l < divisions; ++l) {
/* find the coarsest division level this tick falls on */
unsigned level = divisions;
for (unsigned d = divisions; d >= 4; d /= 2) {
if (l % (divisions / d) == 0) {
level = d;
}
}
/* draw line with alpha corresponding to coarsest level */
const uint8_t a = max(0, (int)rint(UINT_RGBA_A(base) / (0.75 * log2(level))));
const uint32_t c = UINT_RGBA_CHANGE_A(base, a);
const framepos_t f = b->frame + (l * (fpb / (double)divisions));
if (f > leftmost_frame) {
lines.add (PublicEditor::instance().sample_to_pixel_unrounded (f), 1.0, c);
}
}
}
void
TempoLines::draw (const ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
const ARDOUR::TempoMap::BBTPointList::const_iterator& end,
unsigned divisions,
framecnt_t leftmost_frame,
framecnt_t frame_rate)
{
ARDOUR::TempoMap::BBTPointList::const_iterator i;
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) / lines.canvas()->width();
if (beat_density > 4.0f) {
/* if the lines are too close together, they become useless */
lines.clear ();
return;
}
/* constrain divisions to a log2 factor to cap line density */
while (divisions > 3 && beat_density * divisions > 0.4) {
divisions /= 2;
}
lines.clear ();
if (beat_density < 0.1 && begin != end && begin->frame > 0) {
/* draw subdivisions of the beat before the first visible beat line */
ARDOUR::TempoMap::BBTPointList::const_iterator prev = begin;
--prev;
draw_ticks(prev, divisions, leftmost_frame, frame_rate);
}
for (i = begin; i != end; ++i) {
if ((*i).is_bar()) {
color = ARDOUR_UI::config()->color ("measure line bar");
} else {
if (beat_density > 0.3) {
continue; /* only draw beat lines if the gaps between beats are large. */
}
color = ARDOUR_UI::config()->color_mod ("measure line beat", "measure line beat");
}
ArdourCanvas::Coord xpos = PublicEditor::instance().sample_to_pixel_unrounded ((*i).frame);
lines.add (xpos, 1.0, color);
if (beat_density < 0.1) {
/* draw subdivisions of this beat */
draw_ticks(i, divisions, leftmost_frame, frame_rate);
}
}
}