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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.
*/
#ifndef __CANVAS_IMAGE__
#define __CANVAS_IMAGE__
#include <stdint.h>
#include <boost/shared_ptr.hpp>
#include <boost/shared_array.hpp>
#include "canvas/visibility.h"
#include "canvas/item.h"
typedef void (*ImageReleaseCallback)(uint8_t *d, void *arg);
namespace ArdourCanvas {
class LIBCANVAS_API Image : public Item
{
public:
Image (Canvas *, Cairo::Format, int width, int height);
Image (Item*, Cairo::Format, int width, int height);
struct Data {
Data (uint8_t *d, int w, int h, int s, Cairo::Format fmt)
: data (d)
, width (w)
, height (h)
, stride (s)
, format (fmt)
, destroy_callback(NULL)
, destroy_arg(NULL)
{}
virtual ~Data () {
if (destroy_callback) {
destroy_callback(data, destroy_arg);
} else {
free(data);
}
}
uint8_t* data;
int width;
int height;
int stride;
Cairo::Format format;
ImageReleaseCallback destroy_callback;
void* destroy_arg;
};
/**
* Returns a shared_ptr to a Data object that can be used to
* write image data to. The Data object will contain a pointer
* to the buffer, along with image properties that may be
* useful during the data writing.
*
* Can be called from any thread BUT ..
*
* ... to avoid collisions with Image deletion, some synchronization method
* may be required or the use of shared_ptr<Image> or similar.
*/
boost::shared_ptr<Data> get_image (bool allocate_data = true);
/**
* Queues a Data object to be used to redraw this Image item
* at the earliest possible opportunity.
*
* May be called from any thread BUT ...
*
* ... to avoid collisions with Image deletion, some synchronization method
* may be required or the use of shared_ptr<Image> or similar.
*/
void put_image (boost::shared_ptr<Data>);
void render (Rect const &, Cairo::RefPtr<Cairo::Context>) const;
void compute_bounding_box () const;
private:
Cairo::Format _format;
int _width;
int _height;
mutable boost::shared_ptr<Data> _current;
boost::shared_ptr<Data> _pending;
mutable bool _need_render;
mutable Cairo::RefPtr<Cairo::Surface> _surface;
void accept_data ();
PBD::Signal0<void> DataReady;
PBD::ScopedConnectionList data_connections;
};
}
#endif
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