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/*
Copyright (C) 2011-2013 Paul Davis
Author: Carl Hetherington <cth@carlh.net>
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 "canvas/poly_line.h"
#include "canvas/canvas.h"
#include "canvas/utils.h"
using namespace ArdourCanvas;
PolyLine::PolyLine (Canvas* c)
: PolyItem (c)
, _threshold (1.0)
{
}
PolyLine::PolyLine (Item* parent)
: PolyItem (parent)
, _threshold (1.0)
{
}
void
PolyLine::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
{
if (_outline) {
setup_outline_context (context);
render_path (area, context);
context->stroke ();
}
}
void
PolyLine::set_steps (Points const & points, bool stepped)
{
if (!stepped) {
PolyItem::set(points);
return;
}
Points copy;
for (Points::const_iterator p = points.begin(); p != points.end();) {
Points::const_iterator next = p;
++next;
copy.push_back(*p);
if (next != points.end() && next->x != p->x) {
copy.push_back(Duple(next->x, p->y));
}
p = next;
}
PolyItem::set(copy);
}
bool
PolyLine::covers (Duple const & point) const
{
Duple p = window_to_item (point);
const Points::size_type npoints = _points.size();
if (npoints < 2) {
return false;
}
Points::size_type i;
Points::size_type j;
/* repeat for each line segment */
const Rect visible (window_to_item (_canvas->visible_area()));
for (i = 1, j = 0; i < npoints; ++i, ++j) {
Duple at;
double t;
Duple a (_points[j]);
Duple b (_points[i]);
/*
Clamp the line endpoints to the visible area of the canvas. If we do
not do this, we may have a line segment extending to COORD_MAX and our
math goes wrong.
*/
a.x = std::min (a.x, visible.x1);
a.y = std::min (a.y, visible.y1);
b.x = std::min (b.x, visible.x1);
b.y = std::min (b.y, visible.y1);
double d = distance_to_segment_squared (p, a, b, t, at);
if (t < 0.0 || t > 1.0) {
continue;
}
if (d < _threshold + _outline_width) {
return true;
}
}
return false;
}
void
PolyLine::set_covers_threshold (double t)
{
_threshold = t;
}
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