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livetrax/libs/canvas/wave_view.cc

301 lines
6.3 KiB
C++

/*
Copyright (C) 2011-2013 Paul Davis
Author: Carl Hetherington <cth@carlh.net>
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 <cairomm/cairomm.h>
#include "gtkmm2ext/utils.h"
#include "pbd/compose.h"
#include "pbd/signals.h"
#include "ardour/types.h"
#include "ardour/audioregion.h"
#include "canvas/wave_view.h"
#include "canvas/utils.h"
#include <gdkmm/general.h>
using namespace std;
using namespace ARDOUR;
using namespace ArdourCanvas;
WaveView::WaveView (Group* parent, boost::shared_ptr<ARDOUR::AudioRegion> region)
: Item (parent)
, Outline (parent)
, Fill (parent)
, _region (region)
, _channel (0)
, _samples_per_pixel (0)
, _height (64)
, _wave_color (0xffffffff)
, _region_start (0)
{
}
void
WaveView::set_samples_per_pixel (double samples_per_pixel)
{
begin_change ();
_samples_per_pixel = samples_per_pixel;
_bounding_box_dirty = true;
end_change ();
invalidate_whole_cache ();
}
void
WaveView::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
{
assert (_samples_per_pixel != 0);
if (!_region) {
return;
}
/* p, start and end are offsets from the start of the source.
area is relative to the position of the region.
*/
int const start = rint (area.x0 + _region_start / _samples_per_pixel);
int const end = rint (area.x1 + _region_start / _samples_per_pixel);
int p = start;
list<CacheEntry*>::iterator cache = _cache.begin ();
while (p < end) {
/* Step through cache entries that end at or before our current position, p */
while (cache != _cache.end() && (*cache)->end() <= p) {
++cache;
}
/* Now either:
1. we have run out of cache entries
2. the one we are looking at finishes after p but also starts after p.
3. the one we are looking at finishes after p and starts before p.
Set up a pointer to the cache entry that we will use on this iteration.
*/
CacheEntry* render = 0;
if (cache == _cache.end ()) {
/* Case 1: we have run out of cache entries, so make a new one for
the whole required area and put it in the list.
*/
CacheEntry* c = new CacheEntry (this, p, end);
_cache.push_back (c);
render = c;
} else if ((*cache)->start() > p) {
/* Case 2: we have a cache entry, but it starts after p, so we
need another one for the missing bit.
*/
CacheEntry* c = new CacheEntry (this, p, (*cache)->start());
cache = _cache.insert (cache, c);
++cache;
render = c;
} else {
/* Case 3: we have a cache entry that will do at least some of what
we have left, so render it.
*/
render = *cache;
++cache;
}
int const this_end = min (end, render->end ());
Coord const left = p - _region_start / _samples_per_pixel;
Coord const right = this_end - _region_start / _samples_per_pixel;
context->save ();
context->rectangle (left, area.y0, right, area.height());
context->clip ();
context->translate (left, 0);
context->set_source (render->image(), render->start() - p, 0);
context->paint ();
context->restore ();
p = min (end, render->end ());
}
}
void
WaveView::compute_bounding_box () const
{
if (_region) {
_bounding_box = Rect (0, 0, _region->length() / _samples_per_pixel, _height);
} else {
_bounding_box = boost::optional<Rect> ();
}
_bounding_box_dirty = false;
}
void
WaveView::set_height (Distance height)
{
begin_change ();
_height = height;
_bounding_box_dirty = true;
end_change ();
invalidate_image_cache ();
}
void
WaveView::set_channel (int channel)
{
begin_change ();
_channel = channel;
_bounding_box_dirty = true;
end_change ();
invalidate_whole_cache ();
}
void
WaveView::invalidate_whole_cache ()
{
for (list<CacheEntry*>::iterator i = _cache.begin(); i != _cache.end(); ++i) {
delete *i;
}
_cache.clear ();
}
void
WaveView::invalidate_image_cache ()
{
for (list<CacheEntry*>::iterator i = _cache.begin(); i != _cache.end(); ++i) {
(*i)->clear_image ();
}
}
void
WaveView::region_resized ()
{
_bounding_box_dirty = true;
}
void
WaveView::set_region_start (frameoffset_t start)
{
_region_start = start;
_bounding_box_dirty = true;
}
/** Construct a new CacheEntry with peak data between two offsets
* in the source.
*/
WaveView::CacheEntry::CacheEntry (
WaveView const * wave_view,
int start,
int end
)
: _wave_view (wave_view)
, _start (start)
, _end (end)
{
_n_peaks = _end - _start;
_peaks.reset (new PeakData[_n_peaks]);
_wave_view->_region->read_peaks (
_peaks.get(),
_n_peaks,
_start * _wave_view->_samples_per_pixel,
(_end - _start) * _wave_view->_samples_per_pixel,
_wave_view->_channel,
_wave_view->_samples_per_pixel
);
}
WaveView::CacheEntry::~CacheEntry ()
{
}
Cairo::RefPtr<Cairo::ImageSurface>
WaveView::CacheEntry::image ()
{
if (!_image) {
_image = Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, _n_peaks, _wave_view->_height);
Cairo::RefPtr<Cairo::Context> context = Cairo::Context::create (_image);
_wave_view->setup_outline_context (context);
context->move_to (0.5, position (_peaks[0].min));
for (int i = 1; i < _n_peaks; ++i) {
context->line_to (i + 0.5, position (_peaks[i].max));
}
context->stroke ();
context->move_to (0.5, position (_peaks[0].min));
for (int i = 1; i < _n_peaks; ++i) {
context->line_to (i + 0.5, position (_peaks[i].min));
}
context->stroke ();
set_source_rgba (context, _wave_view->_fill_color);
for (int i = 0; i < _n_peaks; ++i) {
context->move_to (i + 0.5, position (_peaks[i].max) - 1);
context->line_to (i + 0.5, position (_peaks[i].min) + 1);
context->stroke ();
}
}
return _image;
}
Coord
WaveView::CacheEntry::position (float s) const
{
return (s + 1) * _wave_view->_height / 2;
}
void
WaveView::CacheEntry::clear_image ()
{
_image.clear ();
}