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add Canvas::Arc and derive Canvas::Circle from it

This commit is contained in:
Paul Davis 2013-04-18 21:28:11 -04:00
parent 5bb213f53b
commit 8482ce14ce
2 changed files with 183 additions and 0 deletions

120
libs/canvas/arc.cc Normal file
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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 <algorithm>
#include <cairomm/context.h>
#include "pbd/compose.h"
#include "canvas/circle.h"
#include "canvas/types.h"
#include "canvas/debug.h"
#include "canvas/utils.h"
#include "canvas/canvas.h"
using namespace std;
using namespace ArdourCanvas;
Arc::Arc (Group* parent)
: Item (parent)
, Outline (parent)
, Fill (parent)
, _radius (0.0)
, _arc_degrees (0.0)
, _start_degrees (0.0)
{
}
void
Arc::compute_bounding_box () const
{
Rect bbox;
/* this could be smaller in the case of small _arc values
but I can't be bothered to optimize it.
*/
bbox.x0 = _center.x - _radius;
bbox.y0 = _center.y - _radius;
bbox.x1 = _center.x + _radius;
bbox.y1 = _center.y + _radius;
bbox = bbox.expand (0.5 + (_outline_width / 2));
_bounding_box = bbox;
_bounding_box_dirty = false;
}
void
Arc::render (Rect const & /*area*/, Cairo::RefPtr<Cairo::Context> context) const
{
if (_radius <= 0.0 || _arc_degrees <= 0.0) {
return;
}
context->arc (_center.x, _center.y, _radius, _start_degrees * (M_PI/180.0), _arc_degrees * (M_PI/180.0));
setup_fill_context (context);
context->fill_preserve ();
setup_outline_context (context);
context->stroke ();
}
void
Arc::set_center (Duple const & c)
{
begin_change ();
_center = c;
_bounding_box_dirty = true;
end_change ();
}
void
Arc::set_radius (Coord r)
{
begin_change ();
_radius = r;
_bounding_box_dirty = true;
end_change ();
}
void
Arc::set_arc (double deg)
{
begin_change ();
_arc_degrees = deg;
_bounding_box_dirty = true;
end_change ();
}
void
Arc::set_start (double deg)
{
begin_change ();
_start_degrees = deg;
_bounding_box_dirty = true;
end_change ();
}

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libs/canvas/canvas/arc.h Normal file
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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_ARC_H__
#define __CANVAS_ARC_H__
#include "canvas/item.h"
#include "canvas/outline.h"
#include "canvas/fill.h"
namespace ArdourCanvas {
class Arc : virtual public Item, public Outline, public Fill
{
public:
Arc (Group *);
void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
void compute_bounding_box () const;
void set_center (Duple const &);
void set_radius (Coord);
void set_arc (double degrees);
void set_start (double degrees);
Duple center() const {
return _center;
}
Coord radius () const {
return _radius;
}
double arc_degrees () const {
return _arc_degrees;
}
double start_degrees () const {
return _start_degrees;
}
private:
Duple _center;
Coord _radius;
double _arc_degrees;
double _start_degrees;
};
}
#endif