ardour/gtk2_ardour/tempo_lines.cc
nick_m 33e95a1577 rename Tempo _beats_per_minute to _note_types_per_minute, provide pulse helpers.
- adds quarter_notes_per_minute(), note_divisions_per_minute (double)
	  pulses_per_minute() and frames_per_quarter_note()

	- this should be a no-op except for the use of tempo by
	  the vst callback which definitely uses quarter notes per minute.

	- the XML node for TempoSection named 'beats-per-minute'
	  has been renamed.
2016-11-11 03:37:08 +11:00

191 lines
5.7 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 "tempo_lines.h"
#include "public_editor.h"
#include "rgb_macros.h"
#include "ui_config.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 (std::vector<ARDOUR::TempoMap::BBTPoint>& grid,
unsigned divisions,
framecnt_t leftmost_frame,
framecnt_t frame_rate)
{
const uint32_t base = UIConfiguration::instance().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(8, (int)rint(UINT_RGBA_A(base) / (0.8 * log2(level))));
const uint32_t c = UINT_RGBA_CHANGE_A(base, a);
framepos_t f = 0;
if (grid.begin()->c != 0.0) {
const double beat_divisions = (l / ((double) divisions)) * (grid.begin()->tempo.note_type() / grid.begin()->meter.note_divisor());
const double time_at_division = log (((grid.begin()->c * (beat_divisions)) /
grid.begin()->tempo.note_types_per_minute()) + 1) / grid.begin()->c;
f = grid.begin()->frame + (framecnt_t) floor ((time_at_division * 60.0 * frame_rate) + 0.5);
} else {
const double fpb = grid.begin()->tempo.frames_per_note_type (frame_rate)
* (grid.begin()->tempo.note_type() / grid.begin()->meter.note_divisor());
f = grid.begin()->frame + (l * (fpb / (double) divisions));
}
if (f > leftmost_frame) {
lines.add (PublicEditor::instance().sample_to_pixel_unrounded (f), 1.0, c);
}
}
}
void
TempoLines::draw (std::vector<ARDOUR::TempoMap::BBTPoint>& grid,
unsigned divisions,
framecnt_t leftmost_frame,
framecnt_t frame_rate)
{
std::vector<ARDOUR::TempoMap::BBTPoint>::const_iterator i;
double beat_density;
uint32_t beats = 0;
uint32_t bars = 0;
const uint32_t bar_color = UIConfiguration::instance().color ("measure line bar");
const uint32_t beat_color = UIConfiguration::instance().color_mod ("measure line beat", "measure line beat");
uint32_t color;
bool all_bars = false;
/* get the first bar spacing */
i = grid.end();
i--;
bars = (*i).bar - (*grid.begin()).bar;
int32_t bar_mod = 4;
if (bars < distance (grid.begin(), grid.end()) - 1) {
/* grid contains beats and bars */
beats = distance (grid.begin(), grid.end()) - bars;
} else {
/* grid contains only bars */
beats = distance (grid.begin(), grid.end());
if (i != grid.begin()) {
const int32_t last_bar = (*i).bar;
i--;
bar_mod = (last_bar - (*i).bar) * 4;
}
all_bars = true;
}
double canvas_width_used = 1.0;
if (leftmost_frame < grid.front().frame) {
const framecnt_t frame_distance = max ((framecnt_t) 1, grid.back().frame - grid.front().frame);
canvas_width_used = 1.0 - ((grid.front().frame - leftmost_frame) / (double) (frame_distance + grid.front().frame));
}
beat_density = (beats * 10.0f) / (lines.canvas()->width() * canvas_width_used);
if (beat_density > 2.0f) {
/* 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 <= 0.12 && grid.begin() != grid.end() && grid.begin()->frame > 0 && !all_bars) {
/* draw subdivisions of the beat before the first visible beat line XX this shouldn't happen now */
std::vector<ARDOUR::TempoMap::BBTPoint> vec;
vec.push_back (*i);
draw_ticks (vec, divisions, leftmost_frame, frame_rate);
}
for (i = grid.begin(); i != grid.end(); ++i) {
if ((*i).is_bar()) {
/* keep all_bar beat density down */
if (all_bars && beat_density > 0.3 && ((*i).bar % bar_mod) != 1) {
continue;
}
color = bar_color;
} else {
if (beat_density > 0.3) {
continue; /* only draw beat lines if the gaps between beats are large. */
}
color = beat_color;
}
ArdourCanvas::Coord xpos = PublicEditor::instance().sample_to_pixel_unrounded ((*i).frame);
lines.add (xpos, 1.0, color);
if (beat_density <= 0.12 && !all_bars) {
/* draw subdivisions of this beat */
std::vector<ARDOUR::TempoMap::BBTPoint> vec;
vec.push_back (*i);
draw_ticks (vec, divisions, leftmost_frame, frame_rate);
}
}
}