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livetrax/libs/waveview/wave_view.cc

1430 lines
38 KiB
C++

/*
Copyright (C) 2011-2013 Paul Davis
Copyright (C) 2017 Tim Mayberry
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 <cmath>
#include <boost/scoped_array.hpp>
#include <cairomm/cairomm.h>
#include <glibmm/threads.h>
#include <gdkmm/general.h>
#include "pbd/base_ui.h"
#include "pbd/compose.h"
#include "pbd/convert.h"
#include "pbd/signals.h"
#include "pbd/stacktrace.h"
#include "ardour/types.h"
#include "ardour/dB.h"
#include "ardour/lmath.h"
#include "ardour/audioregion.h"
#include "ardour/audiosource.h"
#include "ardour/session.h"
#include "gtkmm2ext/colors.h"
#include "gtkmm2ext/gui_thread.h"
#include "gtkmm2ext/utils.h"
#include "canvas/canvas.h"
#include "canvas/debug.h"
#include "waveview/wave_view.h"
#include "waveview/wave_view_private.h"
#ifdef __APPLE__
#define Rect ArdourCanvas::Rect
#endif
using namespace std;
using namespace PBD;
using namespace ARDOUR;
using namespace Gtkmm2ext;
using namespace ArdourCanvas;
using namespace ArdourWaveView;
double WaveView::_global_gradient_depth = 0.6;
bool WaveView::_global_logscaled = false;
WaveView::Shape WaveView::_global_shape = WaveView::Normal;
bool WaveView::_global_show_waveform_clipping = true;
double WaveView::_global_clip_level = 0.98853;
PBD::Signal0<void> WaveView::VisualPropertiesChanged;
PBD::Signal0<void> WaveView::ClipLevelChanged;
/* NO_THREAD_WAVEVIEWS is defined by the top level wscript
* if --no-threaded-waveviws is provided at the configure step.
*/
#ifndef NO_THREADED_WAVEVIEWS
#define ENABLE_THREADED_WAVEFORM_RENDERING
#endif
WaveView::WaveView (Canvas* c, boost::shared_ptr<ARDOUR::AudioRegion> region)
: Item (c)
, _region (region)
, _props (new WaveViewProperties (region))
, _shape_independent (false)
, _logscaled_independent (false)
, _gradient_depth_independent (false)
, _draw_image_in_gui_thread (false)
, _always_draw_image_in_gui_thread (false)
{
init ();
}
WaveView::WaveView (Item* parent, boost::shared_ptr<ARDOUR::AudioRegion> region)
: Item (parent)
, _region (region)
, _props (new WaveViewProperties (region))
, _shape_independent (false)
, _logscaled_independent (false)
, _gradient_depth_independent (false)
, _draw_image_in_gui_thread (false)
, _always_draw_image_in_gui_thread (false)
{
init ();
}
void
WaveView::init ()
{
#ifdef ENABLE_THREADED_WAVEFORM_RENDERING
WaveViewThreads::initialize ();
#endif
_props->fill_color = _fill_color;
_props->outline_color = _outline_color;
VisualPropertiesChanged.connect_same_thread (
invalidation_connection, boost::bind (&WaveView::handle_visual_property_change, this));
ClipLevelChanged.connect_same_thread (invalidation_connection,
boost::bind (&WaveView::handle_clip_level_change, this));
}
WaveView::~WaveView ()
{
#ifdef ENABLE_THREADED_WAVEFORM_RENDERING
WaveViewThreads::deinitialize ();
#endif
reset_cache_group ();
}
string
WaveView::debug_name() const
{
return _region->name () + string (":") + PBD::to_string (_props->channel + 1);
}
void
WaveView::set_always_get_image_in_thread (bool yn)
{
_always_draw_image_in_gui_thread = yn;
}
void
WaveView::handle_visual_property_change ()
{
bool changed = false;
if (!_shape_independent && (_props->shape != global_shape())) {
_props->shape = global_shape();
changed = true;
}
if (!_logscaled_independent && (_props->logscaled != global_logscaled())) {
_props->logscaled = global_logscaled();
changed = true;
}
if (!_gradient_depth_independent && (_props->gradient_depth != global_gradient_depth())) {
_props->gradient_depth = global_gradient_depth();
changed = true;
}
if (changed) {
begin_visual_change ();
end_visual_change ();
}
}
void
WaveView::handle_clip_level_change ()
{
begin_visual_change ();
end_visual_change ();
}
void
WaveView::set_fill_color (Color c)
{
if (c != _fill_color) {
begin_visual_change ();
Fill::set_fill_color (c);
_props->fill_color = _fill_color; // ugh
end_visual_change ();
}
}
void
WaveView::set_outline_color (Color c)
{
if (c != _outline_color) {
begin_visual_change ();
Outline::set_outline_color (c);
_props->outline_color = c;
end_visual_change ();
}
}
void
WaveView::set_samples_per_pixel (double samples_per_pixel)
{
if (_props->samples_per_pixel != samples_per_pixel) {
begin_change ();
_props->samples_per_pixel = samples_per_pixel;
_bounding_box_dirty = true;
end_change ();
}
}
static inline float
_log_meter (float power, double lower_db, double upper_db, double non_linearity)
{
return (power < lower_db ? 0.0 : pow((power-lower_db)/(upper_db-lower_db), non_linearity));
}
static inline float
alt_log_meter (float power)
{
return _log_meter (power, -192.0, 0.0, 8.0);
}
void
WaveView::set_clip_level (double dB)
{
const double clip_level = dB_to_coefficient (dB);
if (_global_clip_level != clip_level) {
_global_clip_level = clip_level;
ClipLevelChanged ();
}
}
boost::shared_ptr<WaveViewDrawRequest>
WaveView::create_draw_request (WaveViewProperties const& props) const
{
assert (props.is_valid());
boost::shared_ptr<WaveViewDrawRequest> request (new WaveViewDrawRequest);
request->image = boost::shared_ptr<WaveViewImage> (new WaveViewImage (_region, props));
return request;
}
void
WaveView::prepare_for_render (Rect const& area) const
{
if (draw_image_in_gui_thread()) {
// Drawing image in GUI thread in WaveView::render
return;
}
Rect draw_rect;
Rect self_rect;
// all in window coordinate space
if (!get_item_and_draw_rect_in_window_coords (area, self_rect, draw_rect)) {
return;
}
double const image_start_pixel_offset = draw_rect.x0 - self_rect.x0;
double const image_end_pixel_offset = draw_rect.x1 - self_rect.x0;
WaveViewProperties required_props = *_props;
required_props.set_sample_positions_from_pixel_offsets (image_start_pixel_offset,
image_end_pixel_offset);
if (!required_props.is_valid ()) {
return;
}
if (_image) {
if (_image->props.is_equivalent (required_props)) {
return;
} else {
// Image does not contain sample area required
}
}
boost::shared_ptr<WaveViewDrawRequest> request = create_draw_request (required_props);
queue_draw_request (request);
}
bool
WaveView::get_item_and_draw_rect_in_window_coords (Rect const& canvas_rect, Rect& item_rect,
Rect& draw_rect) const
{
/* a WaveView is intimately connected to an AudioRegion. It will
* display the waveform within the region, anywhere from the start of
* the region to its end.
*
* the area we've been asked to render may overlap with area covered
* by the region in any of the normal ways:
*
* - it may begin and end within the area covered by the region
* - it may start before and end after the area covered by region
* - it may start before and end within the area covered by the region
* - it may start within and end after the area covered by the region
* - it may be precisely coincident with the area covered by region.
*
* So let's start by determining the area covered by the region, in
* window coordinates. It begins at zero (in item coordinates for this
* waveview, and extends to region_length() / _samples_per_pixel.
*/
double const width = region_length() / _props->samples_per_pixel;
item_rect = item_to_window (Rect (0.0, 0.0, width, _props->height));
/* Now lets get the intersection with the area we've been asked to draw */
draw_rect = item_rect.intersection (canvas_rect);
if (!draw_rect) {
// No intersection with drawing area
return false;
}
/* draw_rect now defines the rectangle we need to update/render the waveview
* into, in window coordinate space.
*
* We round down in case we were asked to draw "between" pixels at the start
* and/or end.
*/
draw_rect.x0 = floor (draw_rect.x0);
draw_rect.x1 = floor (draw_rect.x1);
return true;
}
void
WaveView::queue_draw_request (boost::shared_ptr<WaveViewDrawRequest> const& request) const
{
// Don't enqueue any requests without a thread to dequeue them.
assert (WaveViewThreads::enabled());
if (!request || !request->is_valid()) {
return;
}
if (current_request) {
current_request->cancel ();
}
boost::shared_ptr<WaveViewImage> cached_image =
get_cache_group ()->lookup_image (request->image->props);
if (cached_image) {
// The image may not be finished at this point but that is fine, great in
// fact as it means it should only need to be drawn once.
request->image = cached_image;
current_request = request;
} else {
// now we can finally set an optimal image now that we are not using the
// properties for comparisons.
request->image->props.set_width_samples (optimal_image_width_samples ());
current_request = request;
// Add it to the cache so that other WaveViews can refer to the same image
get_cache_group()->add_image (current_request->image);
WaveViewThreads::enqueue_draw_request (current_request);
}
}
void
WaveView::compute_tips (ARDOUR::PeakData const& peak, WaveView::LineTips& tips,
double const effective_height)
{
/* remember: canvas (and cairo) coordinate space puts the origin at the upper left.
So, a sample value of 1.0 (0dbFS) will be computed as:
(1.0 - 1.0) * 0.5 * effective_height
which evaluates to 0, or the top of the image.
A sample value of -1.0 will be computed as
(1.0 + 1.0) * 0.5 * effective height
which evaluates to effective height, or the bottom of the image.
*/
const double pmax = (1.0 - peak.max) * 0.5 * effective_height;
const double pmin = (1.0 - peak.min) * 0.5 * effective_height;
/* remember that the bottom of the image (pmin) has larger y-coordinates
than the top (pmax).
*/
double spread = (pmin - pmax) * 0.5;
/* find the nearest pixel to the nominal center. */
const double center = round (pmin - spread);
if (spread < 1.0) {
/* minimum distance between line ends is 1 pixel, and we want it "centered" on a pixel,
as per cairo single-pixel line issues.
NOTE: the caller will not draw a line between these two points if the spread is
less than 2 pixels. So only the tips.top value matters, which is where we will
draw a single pixel as part of the outline.
*/
tips.top = center;
tips.bot = center + 1.0;
} else {
/* round spread above and below center to an integer number of pixels */
spread = round (spread);
/* top and bottom are located equally either side of the center */
tips.top = center - spread;
tips.bot = center + spread;
}
tips.top = min (effective_height, max (0.0, tips.top));
tips.bot = min (effective_height, max (0.0, tips.bot));
}
Coord
WaveView::y_extent (double s, Shape const shape, double const height)
{
assert (shape == Rectified);
return floor ((1.0 - s) * height);
}
void
WaveView::draw_absent_image (Cairo::RefPtr<Cairo::ImageSurface>& image, PeakData* peaks, int n_peaks)
{
const double height = image->get_height();
Cairo::RefPtr<Cairo::ImageSurface> stripe = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, height);
Cairo::RefPtr<Cairo::Context> stripe_context = Cairo::Context::create (stripe);
stripe_context->set_antialias (Cairo::ANTIALIAS_NONE);
uint32_t stripe_separation = 150;
double start = - floor (height / stripe_separation) * stripe_separation;
int stripe_x = 0;
while (start < n_peaks) {
stripe_context->move_to (start, 0);
stripe_x = start + height;
stripe_context->line_to (stripe_x, height);
start += stripe_separation;
}
stripe_context->set_source_rgba (1.0, 1.0, 1.0, 1.0);
stripe_context->set_line_cap (Cairo::LINE_CAP_SQUARE);
stripe_context->set_line_width(50);
stripe_context->stroke();
Cairo::RefPtr<Cairo::Context> context = Cairo::Context::create (image);
context->set_source_rgba (1.0, 1.0, 0.0, 0.3);
context->mask (stripe, 0, 0);
context->fill ();
}
struct ImageSet {
Cairo::RefPtr<Cairo::ImageSurface> wave;
Cairo::RefPtr<Cairo::ImageSurface> outline;
Cairo::RefPtr<Cairo::ImageSurface> clip;
Cairo::RefPtr<Cairo::ImageSurface> zero;
ImageSet() :
wave (0), outline (0), clip (0), zero (0) {}
};
void
WaveView::draw_image (Cairo::RefPtr<Cairo::ImageSurface>& image, PeakData* peaks, int n_peaks,
boost::shared_ptr<WaveViewDrawRequest> req)
{
const double height = image->get_height();
ImageSet images;
images.wave = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, height);
images.outline = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, height);
images.clip = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, height);
images.zero = Cairo::ImageSurface::create (Cairo::FORMAT_A8, n_peaks, height);
Cairo::RefPtr<Cairo::Context> wave_context = Cairo::Context::create (images.wave);
Cairo::RefPtr<Cairo::Context> outline_context = Cairo::Context::create (images.outline);
Cairo::RefPtr<Cairo::Context> clip_context = Cairo::Context::create (images.clip);
Cairo::RefPtr<Cairo::Context> zero_context = Cairo::Context::create (images.zero);
wave_context->set_antialias (Cairo::ANTIALIAS_NONE);
outline_context->set_antialias (Cairo::ANTIALIAS_NONE);
clip_context->set_antialias (Cairo::ANTIALIAS_NONE);
zero_context->set_antialias (Cairo::ANTIALIAS_NONE);
boost::scoped_array<LineTips> tips (new LineTips[n_peaks]);
/* Clip level nominally set to -0.9dBFS to account for inter-sample
interpolation possibly clipping (value may be too low).
We adjust by the region's own gain (but note: not by any gain
automation or its gain envelope) so that clip indicators are closer
to providing data about on-disk data. This multiplication is
needed because the data we get from AudioRegion::read_peaks()
has been scaled by scale_amplitude() already.
*/
const double clip_level = _global_clip_level * req->image->props.amplitude;
const Shape shape = req->image->props.shape;
const bool logscaled = req->image->props.logscaled;
if (req->image->props.shape == WaveView::Rectified) {
/* each peak is a line from the bottom of the waveview
* to a point determined by max (peaks[i].max,
* peaks[i].min)
*/
if (logscaled) {
for (int i = 0; i < n_peaks; ++i) {
tips[i].bot = height - 1.0;
const double p = alt_log_meter (fast_coefficient_to_dB (max (fabs (peaks[i].max), fabs (peaks[i].min))));
tips[i].top = y_extent (p, shape, height);
tips[i].spread = p * height;
if (peaks[i].max >= clip_level) {
tips[i].clip_max = true;
}
if (-(peaks[i].min) >= clip_level) {
tips[i].clip_min = true;
}
}
} else {
for (int i = 0; i < n_peaks; ++i) {
tips[i].bot = height - 1.0;
const double p = max(fabs (peaks[i].max), fabs (peaks[i].min));
tips[i].top = y_extent (p, shape, height);
tips[i].spread = p * height;
if (p >= clip_level) {
tips[i].clip_max = true;
}
}
}
} else {
if (logscaled) {
for (int i = 0; i < n_peaks; ++i) {
PeakData p;
p.max = peaks[i].max;
p.min = peaks[i].min;
if (peaks[i].max >= clip_level) {
tips[i].clip_max = true;
}
if (-(peaks[i].min) >= clip_level) {
tips[i].clip_min = true;
}
if (p.max > 0.0) {
p.max = alt_log_meter (fast_coefficient_to_dB (p.max));
} else if (p.max < 0.0) {
p.max =-alt_log_meter (fast_coefficient_to_dB (-p.max));
} else {
p.max = 0.0;
}
if (p.min > 0.0) {
p.min = alt_log_meter (fast_coefficient_to_dB (p.min));
} else if (p.min < 0.0) {
p.min = -alt_log_meter (fast_coefficient_to_dB (-p.min));
} else {
p.min = 0.0;
}
compute_tips (p, tips[i], height);
tips[i].spread = tips[i].bot - tips[i].top;
}
} else {
for (int i = 0; i < n_peaks; ++i) {
if (peaks[i].max >= clip_level) {
tips[i].clip_max = true;
}
if (-(peaks[i].min) >= clip_level) {
tips[i].clip_min = true;
}
compute_tips (peaks[i], tips[i], height);
tips[i].spread = tips[i].bot - tips[i].top;
}
}
}
if (req->stopped()) {
return;
}
Color alpha_one = rgba_to_color (0, 0, 0, 1.0);
set_source_rgba (wave_context, alpha_one);
set_source_rgba (outline_context, alpha_one);
set_source_rgba (clip_context, alpha_one);
set_source_rgba (zero_context, alpha_one);
/* ensure single-pixel lines */
wave_context->set_line_width (1.0);
wave_context->translate (0.5, 0.5);
outline_context->set_line_width (1.0);
outline_context->translate (0.5, 0.5);
clip_context->set_line_width (1.0);
clip_context->translate (0.5, 0.5);
zero_context->set_line_width (1.0);
zero_context->translate (0.5, 0.5);
/* the height of the clip-indicator should be at most 7 pixels,
* or 5% of the height of the waveview item.
*/
const double clip_height = min (7.0, ceil (height * 0.05));
/* There are 3 possible components to draw at each x-axis position: the
waveform "line", the zero line and an outline/clip indicator. We
have to decide which of the 3 to draw at each position, pixel by
pixel. This makes the rendering less efficient but it is the only
way I can see to do this correctly.
To avoid constant source swapping and stroking, we draw the components separately
onto four alpha only image surfaces for use as a mask.
With only 1 pixel of spread between the top and bottom of the line,
we just draw the upper outline/clip indicator.
With 2 pixels of spread, we draw the upper and lower outline clip
indicators.
With 3 pixels of spread we draw the upper and lower outline/clip
indicators and at least 1 pixel of the waveform line.
With 5 pixels of spread, we draw all components.
We can do rectified as two separate passes because we have a much
easier decision regarding whether to draw the waveform line. We
always draw the clip/outline indicators.
*/
if (shape == WaveView::Rectified) {
for (int i = 0; i < n_peaks; ++i) {
/* waveform line */
if (tips[i].spread >= 1.0) {
wave_context->move_to (i, tips[i].top);
wave_context->line_to (i, tips[i].bot);
}
/* clip indicator */
if (_global_show_waveform_clipping && (tips[i].clip_max || tips[i].clip_min)) {
clip_context->move_to (i, tips[i].top);
/* clip-indicating upper terminal line */
clip_context->rel_line_to (0, min (clip_height, ceil(tips[i].spread + .5)));
} else {
outline_context->move_to (i, tips[i].top);
/* normal upper terminal dot */
outline_context->rel_line_to (0, -1.0);
}
}
wave_context->stroke ();
clip_context->stroke ();
outline_context->stroke ();
} else {
const int height_zero = floor(height * .5);
for (int i = 0; i < n_peaks; ++i) {
/* waveform line */
if (tips[i].spread >= 2.0) {
wave_context->move_to (i, tips[i].top);
wave_context->line_to (i, tips[i].bot);
}
/* draw square waves and other discontiguous points clearly */
if (i > 0) {
if (tips[i-1].top + 2 < tips[i].top) {
wave_context->move_to (i-1, tips[i-1].top);
wave_context->line_to (i-1, (tips[i].bot + tips[i-1].top)/2);
wave_context->move_to (i, (tips[i].bot + tips[i-1].top)/2);
wave_context->line_to (i, tips[i].top);
} else if (tips[i-1].bot > tips[i].bot + 2) {
wave_context->move_to (i-1, tips[i-1].bot);
wave_context->line_to (i-1, (tips[i].top + tips[i-1].bot)/2);
wave_context->move_to (i, (tips[i].top + tips[i-1].bot)/2);
wave_context->line_to (i, tips[i].bot);
}
}
/* zero line, show only if there is enough spread
or the waveform line does not cross zero line */
bool const show_zero_line = req->image->props.show_zero;
if (show_zero_line && ((tips[i].spread >= 5.0) || (tips[i].top > height_zero ) || (tips[i].bot < height_zero)) ) {
zero_context->move_to (i, height_zero);
zero_context->rel_line_to (1.0, 0);
}
if (tips[i].spread > 1.0) {
bool clipped = false;
/* outline/clip indicators */
if (_global_show_waveform_clipping && tips[i].clip_max) {
clip_context->move_to (i, tips[i].top);
/* clip-indicating upper terminal line */
clip_context->rel_line_to (0, min (clip_height, ceil(tips[i].spread + 0.5)));
clipped = true;
}
if (_global_show_waveform_clipping && tips[i].clip_min) {
clip_context->move_to (i, tips[i].bot);
/* clip-indicating lower terminal line */
clip_context->rel_line_to (0, - min (clip_height, ceil(tips[i].spread + 0.5)));
clipped = true;
}
if (!clipped && tips[i].spread > 2.0) {
/* only draw the outline if the spread
implies 3 or more pixels (so that we see 1
white pixel in the middle).
*/
outline_context->move_to (i, tips[i].bot);
/* normal lower terminal dot; line moves up */
outline_context->rel_line_to (0, -1.0);
outline_context->move_to (i, tips[i].top);
/* normal upper terminal dot, line moves down */
outline_context->rel_line_to (0, 1.0);
}
} else {
bool clipped = false;
/* outline/clip indicator */
if (_global_show_waveform_clipping && (tips[i].clip_max || tips[i].clip_min)) {
clip_context->move_to (i, tips[i].top);
/* clip-indicating upper / lower terminal line */
clip_context->rel_line_to (0, 1.0);
clipped = true;
}
if (!clipped) {
/* special case where only 1 pixel of
* the waveform line is drawn (and
* nothing else).
*
* we draw a 1px "line", pretending
* that the span is 1.0 (whether it is
* zero or 1.0)
*/
wave_context->move_to (i, tips[i].top);
wave_context->rel_line_to (0, 1.0);
}
}
}
wave_context->stroke ();
outline_context->stroke ();
clip_context->stroke ();
zero_context->stroke ();
}
if (req->stopped()) {
return;
}
Cairo::RefPtr<Cairo::Context> context = Cairo::Context::create (image);
/* Here we set a source colour and use the various components as a mask. */
const Color fill_color = req->image->props.fill_color;
const double gradient_depth = req->image->props.gradient_depth;
if (gradient_depth != 0.0) {
Cairo::RefPtr<Cairo::LinearGradient> gradient (Cairo::LinearGradient::create (0, 0, 0, height));
double stops[3];
double r, g, b, a;
if (shape == Rectified) {
stops[0] = 0.1;
stops[1] = 0.3;
stops[2] = 0.9;
} else {
stops[0] = 0.1;
stops[1] = 0.5;
stops[2] = 0.9;
}
color_to_rgba (fill_color, r, g, b, a);
gradient->add_color_stop_rgba (stops[1], r, g, b, a);
/* generate a new color for the middle of the gradient */
double h, s, v;
color_to_hsv (fill_color, h, s, v);
/* change v towards white */
v *= 1.0 - gradient_depth;
Color center = hsva_to_color (h, s, v, a);
color_to_rgba (center, r, g, b, a);
gradient->add_color_stop_rgba (stops[0], r, g, b, a);
gradient->add_color_stop_rgba (stops[2], r, g, b, a);
context->set_source (gradient);
} else {
set_source_rgba (context, fill_color);
}
if (req->stopped()) {
return;
}
context->mask (images.wave, 0, 0);
context->fill ();
set_source_rgba (context, req->image->props.outline_color);
context->mask (images.outline, 0, 0);
context->fill ();
set_source_rgba (context, req->image->props.clip_color);
context->mask (images.clip, 0, 0);
context->fill ();
set_source_rgba (context, req->image->props.zero_color);
context->mask (images.zero, 0, 0);
context->fill ();
}
framecnt_t
WaveView::optimal_image_width_samples () const
{
/* Compute how wide the image should be in samples.
*
* The resulting image should be wider than the canvas width so that the
* image does not have to be redrawn each time the canvas offset changes, but
* drawing too much unnecessarily, for instance when zooming into the canvas
* the part of the image that is outside of the visible canvas area may never
* be displayed and will just increase apparent render time and reduce
* responsiveness in non-threaded rendering and cause "flashing" waveforms in
* threaded rendering mode.
*
* Another thing to consider is that if there are a number of waveforms on
* the canvas that are the width of the canvas then we don't want to have to
* draw the images for them all at once as it will cause a spike in render
* time, or in threaded rendering mode it will mean all the draw requests will
* the queued during the same frame/expose event. This issue can be
* alleviated by using an element of randomness in selecting the image width.
*
* If the value of samples per pixel is less than 1/10th of a second, use
* 1/10th of a second instead.
*/
framecnt_t canvas_width_samples = _canvas->visible_area().width() * _props->samples_per_pixel;
const framecnt_t one_tenth_of_second = _region->session().frame_rate() / 10;
/* If zoomed in where a canvas item interects with the canvas area but
* stretches for many pages either side, to avoid having draw all images when
* the canvas scrolls by a page width the multiplier would have to be a
* randomized amount centered around 3 times the visible canvas width, but
* for other operations like zooming or even with a stationary playhead it is
* a lot of extra drawing that can affect performance.
*
* So without making things too complicated with different widths for
* different operations, try to use a width that is a balance and will work
* well for scrolling(non-page width) so all the images aren't redrawn at the
* same time but also faster for sequential zooming operations.
*
* Canvas items that don't intersect with the edges of the visible canvas
* will of course only draw images that are the pixel width of the item.
*
* It is a perhaps a coincidence that these values are centered roughly
* around the golden ratio but they did work well in my testing.
*/
const double min_multiplier = 1.4;
const double max_multiplier = 1.8;
/**
* A combination of high resolution screens, high samplerates and high
* zoom levels(1 sample per pixel) can cause 1/10 of a second(in
* pixels) to exceed the cairo image size limit.
*/
const double cairo_image_limit = 32767.0;
const double max_image_width = cairo_image_limit / max_multiplier;
framecnt_t max_width_samples = floor (max_image_width / _props->samples_per_pixel);
const framecnt_t one_tenth_of_second_limited = std::min (one_tenth_of_second, max_width_samples);
framecnt_t new_sample_count = std::max (canvas_width_samples, one_tenth_of_second_limited);
const double multiplier = g_random_double_range (min_multiplier, max_multiplier);
return new_sample_count * multiplier;
}
void
WaveView::set_image (boost::shared_ptr<WaveViewImage> img) const
{
get_cache_group ()->add_image (img);
_image = img;
}
void
WaveView::process_draw_request (boost::shared_ptr<WaveViewDrawRequest> req)
{
boost::shared_ptr<const ARDOUR::AudioRegion> region = req->image->region.lock();
if (!region) {
return;
}
if (req->stopped()) {
return;
}
WaveViewProperties const& props = req->image->props;
const int n_peaks = props.get_width_pixels ();
assert (n_peaks > 0 && n_peaks < 32767);
boost::scoped_array<ARDOUR::PeakData> peaks (new PeakData[n_peaks]);
/* Note that Region::read_peaks() takes a start position based on an
offset into the Region's **SOURCE**, rather than an offset into
the Region itself.
*/
framecnt_t peaks_read =
region->read_peaks (peaks.get (), n_peaks, props.get_sample_start (),
props.get_length_samples (), props.channel, props.samples_per_pixel);
if (req->stopped()) {
return;
}
Cairo::RefPtr<Cairo::ImageSurface> cairo_image =
Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, n_peaks, req->image->props.height);
// http://cairographics.org/manual/cairo-Image-Surfaces.html#cairo-image-surface-create
// This function always returns a valid pointer, but it will return a pointer to a "nil" surface..
// but there's some evidence that req->image can be NULL.
// http://tracker.ardour.org/view.php?id=6478
assert (cairo_image);
if (peaks_read > 0) {
/* region amplitude will have been used to generate the
* peak values already, but not the visual-only
* amplitude_above_axis. So apply that here before
* rendering.
*/
const double amplitude_above_axis = props.amplitude_above_axis;
if (amplitude_above_axis != 1.0) {
for (framecnt_t i = 0; i < n_peaks; ++i) {
peaks[i].max *= amplitude_above_axis;
peaks[i].min *= amplitude_above_axis;
}
}
draw_image (cairo_image, peaks.get(), n_peaks, req);
} else {
draw_absent_image (cairo_image, peaks.get(), n_peaks);
}
if (req->stopped ()) {
return;
}
// Assign now that we are sure all drawing is complete as that is what
// determines whether a request was finished.
req->image->cairo_image = cairo_image;
}
bool
WaveView::draw_image_in_gui_thread () const
{
return _draw_image_in_gui_thread || _always_draw_image_in_gui_thread || !rendered () ||
!WaveViewThreads::enabled ();
}
void
WaveView::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
{
assert (_props->samples_per_pixel != 0);
if (!_region) { // assert?
return;
}
Rect draw;
Rect self;
if (!get_item_and_draw_rect_in_window_coords (area, self, draw)) {
assert(true);
return;
}
double const image_start_pixel_offset = draw.x0 - self.x0;
double const image_end_pixel_offset = draw.x1 - self.x0;
if (image_start_pixel_offset == image_end_pixel_offset) {
// this may happen if zoomed very far out with a small region
return;
}
WaveViewProperties required_props = *_props;
required_props.set_sample_positions_from_pixel_offsets (image_start_pixel_offset,
image_end_pixel_offset);
assert (required_props.is_valid());
boost::shared_ptr<WaveViewImage> image_to_draw;
if (current_request) {
if (!current_request->image->props.is_equivalent (required_props)) {
// The WaveView properties may have been updated during recording between
// prepare_for_render and render calls and the new required props have
// different end sample value.
current_request->cancel ();
current_request.reset ();
} else if (current_request->finished ()) {
image_to_draw = current_request->image;
current_request.reset ();
}
} else {
// No current Request
}
if (!image_to_draw && _image) {
if (_image->props.is_equivalent (required_props)) {
// Image contains required properties
image_to_draw = _image;
} else {
// Image does not contain properties required
}
}
if (!image_to_draw) {
image_to_draw = get_cache_group ()->lookup_image (required_props);
if (image_to_draw && !image_to_draw->finished ()) {
// Found equivalent but unfinished Image in cache
image_to_draw.reset ();
}
}
if (!image_to_draw) {
// No existing image to draw
boost::shared_ptr<WaveViewDrawRequest> const request = create_draw_request (required_props);
if (draw_image_in_gui_thread ()) {
// now that we have to draw something, draw more than required.
request->image->props.set_width_samples (optimal_image_width_samples ());
process_draw_request (request);
image_to_draw = request->image;
} else if (current_request) {
if (current_request->finished ()) {
// There is a chance the request is now finished since checking above
image_to_draw = current_request->image;
current_request.reset ();
} else if (_canvas->get_microseconds_since_render_start () < 15000) {
current_request->cancel ();
current_request.reset ();
// Drawing image in GUI thread as we have time
// now that we have to draw something, draw more than required.
request->image->props.set_width_samples (optimal_image_width_samples ());
process_draw_request (request);
image_to_draw = request->image;
} else {
// Waiting for current request to finish
redraw ();
return;
}
} else {
// Defer the rendering to another thread or perhaps render pass if
// a thread cannot generate it in time.
queue_draw_request (request);
redraw ();
return;
}
}
/* reset this so that future missing images can be generated in a worker thread. */
_draw_image_in_gui_thread = false;
assert (image_to_draw);
/* compute the first pixel of the image that should be used when we
* render the specified range.
*/
double image_origin_in_self_coordinates =
(image_to_draw->props.get_sample_start () - _props->region_start) / _props->samples_per_pixel;
/* the image may only be a best-effort ... it may not span the entire
* range requested, though it is guaranteed to cover the start. So
* determine how many pixels we can actually draw.
*/
const double draw_start_pixel = draw.x0;
const double draw_end_pixel = draw.x1;
double draw_width_pixels = draw_end_pixel - draw_start_pixel;
if (image_to_draw != _image) {
/* the image is guaranteed to start at or before
* draw_start. But if it starts before draw_start, that reduces
* the maximum available width we can render with.
*
* so .. clamp the draw width to the smaller of what we need to
* draw or the available width of the image.
*/
draw_width_pixels = min ((double)image_to_draw->cairo_image->get_width (), draw_width_pixels);
set_image (image_to_draw);
}
context->rectangle (draw_start_pixel, draw.y0, draw_width_pixels, draw.height());
/* round image origin position to an exact pixel in device space to
* avoid blurring
*/
double x = self.x0 + image_origin_in_self_coordinates;
double y = self.y0;
context->user_to_device (x, y);
x = round (x);
y = round (y);
context->device_to_user (x, y);
/* the coordinates specify where in "user coordinates" (i.e. what we
* generally call "canvas coordinates" in this code) the image origin
* will appear. So specifying (10,10) will put the upper left corner of
* the image at (10,10) in user space.
*/
context->set_source (image_to_draw->cairo_image, x, y);
context->fill ();
}
void
WaveView::compute_bounding_box () const
{
if (_region) {
_bounding_box = Rect (0.0, 0.0, region_length() / _props->samples_per_pixel, _props->height);
} else {
_bounding_box = Rect ();
}
_bounding_box_dirty = false;
}
void
WaveView::set_height (Distance height)
{
if (_props->height != height) {
begin_change ();
_props->height = height;
_draw_image_in_gui_thread = true;
_bounding_box_dirty = true;
end_change ();
}
}
void
WaveView::set_channel (int channel)
{
if (_props->channel != channel) {
begin_change ();
_props->channel = channel;
reset_cache_group ();
_bounding_box_dirty = true;
end_change ();
}
}
void
WaveView::set_logscaled (bool yn)
{
if (_props->logscaled != yn) {
begin_visual_change ();
_props->logscaled = yn;
end_visual_change ();
}
}
void
WaveView::set_gradient_depth (double)
{
// TODO ??
}
double
WaveView::gradient_depth () const
{
return _props->gradient_depth;
}
void
WaveView::gain_changed ()
{
begin_visual_change ();
_props->amplitude = _region->scale_amplitude ();
_draw_image_in_gui_thread = true;
end_visual_change ();
}
void
WaveView::set_zero_color (Color c)
{
if (_props->zero_color != c) {
begin_visual_change ();
_props->zero_color = c;
end_visual_change ();
}
}
void
WaveView::set_clip_color (Color c)
{
if (_props->clip_color != c) {
begin_visual_change ();
_props->clip_color = c;
end_visual_change ();
}
}
void
WaveView::set_show_zero_line (bool yn)
{
if (_props->show_zero != yn) {
begin_visual_change ();
_props->show_zero = yn;
end_visual_change ();
}
}
bool
WaveView::show_zero_line () const
{
return _props->show_zero;
}
void
WaveView::set_shape (Shape s)
{
if (_props->shape != s) {
begin_visual_change ();
_props->shape = s;
end_visual_change ();
}
}
void
WaveView::set_amplitude_above_axis (double a)
{
if (fabs (_props->amplitude_above_axis - a) > 0.01) {
begin_visual_change ();
_props->amplitude_above_axis = a;
_draw_image_in_gui_thread = true;
end_visual_change ();
}
}
double
WaveView::amplitude_above_axis () const
{
return _props->amplitude_above_axis;
}
void
WaveView::set_global_shape (Shape s)
{
if (_global_shape != s) {
_global_shape = s;
WaveViewCache::get_instance()->clear_cache ();
VisualPropertiesChanged (); /* EMIT SIGNAL */
}
}
void
WaveView::set_global_logscaled (bool yn)
{
if (_global_logscaled != yn) {
_global_logscaled = yn;
WaveViewCache::get_instance()->clear_cache ();
VisualPropertiesChanged (); /* EMIT SIGNAL */
}
}
framecnt_t
WaveView::region_length() const
{
return _region->length() - (_props->region_start - _region->start());
}
framepos_t
WaveView::region_end() const
{
return _props->region_start + region_length();
}
void
WaveView::set_region_start (frameoffset_t start)
{
if (!_region) {
return;
}
if (_props->region_start == start) {
return;
}
begin_change ();
_props->region_start = start;
_bounding_box_dirty = true;
end_change ();
}
void
WaveView::region_resized ()
{
/* Called when the region start or end (thus length) has changed.
*/
if (!_region) {
return;
}
begin_change ();
_props->region_start = _region->start();
_props->region_end = _region->start() + _region->length();
_bounding_box_dirty = true;
end_change ();
}
void
WaveView::set_global_gradient_depth (double depth)
{
if (_global_gradient_depth != depth) {
_global_gradient_depth = depth;
VisualPropertiesChanged (); /* EMIT SIGNAL */
}
}
void
WaveView::set_global_show_waveform_clipping (bool yn)
{
if (_global_show_waveform_clipping != yn) {
_global_show_waveform_clipping = yn;
ClipLevelChanged ();
}
}
void
WaveView::set_start_shift (double pixels)
{
if (pixels < 0) {
return;
}
begin_visual_change ();
//_start_shift = pixels;
end_visual_change ();
}
void
WaveView::set_image_cache_size (uint64_t sz)
{
WaveViewCache::get_instance()->set_image_cache_threshold (sz);
}
boost::shared_ptr<WaveViewCacheGroup>
WaveView::get_cache_group () const
{
if (_cache_group) {
return _cache_group;
}
boost::shared_ptr<AudioSource> source = _region->audio_source (_props->channel);
assert (source);
_cache_group = WaveViewCache::get_instance ()->get_cache_group (source);
return _cache_group;
}
void
WaveView::reset_cache_group ()
{
WaveViewCache::get_instance()->reset_cache_group (_cache_group);
}