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livetrax/libs/canvas/image.cc

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/*
Copyright (C) 2013 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/image.h"
#include "gtkmm2ext/gui_thread.h"
using namespace ArdourCanvas;
Image::Image (Group* group, Cairo::Format fmt, int width, int height)
: Item (group)
, _format (fmt)
, _width (width)
, _height (height)
, _need_render (false)
{
DataReady.connect (data_connections, MISSING_INVALIDATOR, boost::bind (&Image::accept_data, this), gui_context());
}
void
Image::render (Rect const& area, Cairo::RefPtr<Cairo::Context> context) const
{
if (_need_render && _pending) {
_surface = Cairo::ImageSurface::create (_pending->data,
_pending->format,
_pending->width,
_pending->height,
_pending->stride);
_current = _pending;
}
Rect self = item_to_window (Rect (0, 0, _width, _height));
boost::optional<Rect> draw = self.intersection (area);
if (_surface && draw) {
context->set_source (_surface, 0, 0);
context->rectangle (draw->x0, draw->y0, draw->width(), draw->height());
context->fill ();
}
}
void
Image::compute_bounding_box () const
{
_bounding_box = boost::optional<Rect> (Rect (0, 0, _width, _height));
_bounding_box_dirty = false;
}
boost::shared_ptr<Image::Data>
Image::get_image (bool allocate_data)
{
/* can be called by any thread */
int stride = Cairo::ImageSurface::format_stride_for_width (_format, _width);
if (allocate_data) {
boost::shared_ptr<Data> d (new Data (new uint8_t[stride*_height], _width, _height, stride, _format));
return d;
} else {
boost::shared_ptr<Data> d (new Data (NULL, _width, _height, stride, _format));
return d;
}
}
void
Image::put_image (boost::shared_ptr<Data> d)
{
/* can be called by any thread */
_pending = d;
DataReady (); /* EMIT SIGNAL */
}
void
Image::accept_data ()
{
/* must be executed in gui thread */
begin_change ();
_need_render = true;
end_change (); // notify canvas that we need redrawing
}