livetrax/libs/canvas/image.cc

/*
 * Copyright (C) 2013-2015 Robin Gareus <robin@gareus.org>
 * Copyright (C) 2013-2017 Paul Davis <paul@linuxaudiosystems.com>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "canvas/image.h"

#include "gtkmm2ext/gui_thread.h"

using namespace ArdourCanvas;

Image::Image (Canvas* canvas, Cairo::Format fmt, int width, int height)
	: Item (canvas)
	, _format (fmt)
	, _width (width)
	, _height (height)
	, _need_render (false)
{
	DataReady.connect (data_connections, MISSING_INVALIDATOR, boost::bind (&Image::accept_data, this), gui_context());
}

Image::Image (Item* parent, Cairo::Format fmt, int width, int height)
	: Item (parent)
	, _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));
	Rect draw = self.intersection (area);

	if (_surface && draw) {
		context->set_source (_surface, self.x0, self.y0);
		context->rectangle (draw.x0, draw.y0, draw.width(), draw.height());
		context->fill ();
	}
}

void
Image::compute_bounding_box () const
{
	_bounding_box = Rect (0, 0, _width, _height);
	set_bbox_clean ();
}

std::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)  {
		std::shared_ptr<Data> d (new Data (new uint8_t[stride*_height], _width, _height, stride, _format));
		return d;
	} else {
		std::shared_ptr<Data> d (new Data (NULL, _width, _height, stride, _format));
		return d;
	}
}

void
Image::put_image (std::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
}