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livetrax/libs/canvas/arc.cc
Paul Davis 590882f3c8 change Canvas heirarchy and constructors
Items no longer need a parent group (they require a Canvas pointer instead), so all constructors have been rationalized
and have two variants, one with a parent and one with a canvas.

All Items now inherit from Fill and Outline, to banish diagonal inheritance and virtual base classes and all that.

There were zero changes to the Ardour GUI arising from these changes.
2014-06-12 14:53:44 -04:00

143 lines
2.8 KiB
C++

/*
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 <cmath>
#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 (Canvas* c)
: Item (c)
, _radius (0.0)
, _arc_degrees (0.0)
, _start_degrees (0.0)
{
}
Arc::Arc (Group* g)
: Item (g)
, _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;
}
Duple c = item_to_window (Duple (_center.x, _center.y));
context->arc (c.x, c.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 ();
}
bool
Arc::covers (Duple const & point) const
{
Duple p = window_to_item (point);
double angle_degs = atan (p.y/p.x) * 2.0 * M_PI;
double radius = sqrt (p.x * p.x + p.y * p.y);
return (angle_degs >= _start_degrees) &&
(angle_degs <= (_start_degrees + _arc_degrees)) &&
(radius < _radius);
}