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livetrax/libs/canvas/poly_item.cc

168 lines
3.4 KiB
C++

/*
* Copyright (C) 2012 Carl Hetherington <carl@carlh.net>
* 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 <algorithm>
#include "pbd/compose.h"
#include "canvas/canvas.h"
#include "canvas/poly_item.h"
using namespace std;
using namespace ArdourCanvas;
PolyItem::PolyItem (Canvas* c)
: Item (c)
{
}
PolyItem::PolyItem (Item* parent)
: Item (parent)
{
}
void
PolyItem::compute_bounding_box () const
{
if (!_points.empty ()) {
Rect bbox;
Points::const_iterator i = _points.begin ();
bbox.x0 = bbox.x1 = i->x;
bbox.y0 = bbox.y1 = i->y;
++i;
while (i != _points.end ()) {
bbox.x0 = min (bbox.x0, i->x);
bbox.y0 = min (bbox.y0, i->y);
bbox.x1 = max (bbox.x1, i->x);
bbox.y1 = max (bbox.y1, i->y);
++i;
}
_bounding_box = bbox.expand (_outline_width + 0.5);
} else {
_bounding_box = Rect ();
}
set_bbox_clean ();
}
void
PolyItem::render_path (Rect const& area, Cairo::RefPtr<Cairo::Context> context) const
{
if (_points.size () < 2) {
return;
}
const double pixel_adjust = (_outline_width == 1.0 ? 0.5 : 0.0);
Points::const_iterator i = _points.begin ();
Duple c0 = item_to_window (Duple (i->x, i->y));
++i;
while (c0.x < -1.) {
Duple c1 (item_to_window (Duple (i->x, i->y)));
if (interpolate_line (c0, c1, -1)) {
break;
}
if (++i == _points.end ()) {
c1.x = 0;
context->move_to (c1.x + pixel_adjust, c1.y + pixel_adjust);
_left = _right = c1;
return;
}
c0 = c1;
}
context->move_to (c0.x + pixel_adjust, c0.y + pixel_adjust);
_left = c0;
while (i != _points.end ()) {
Duple c = item_to_window (Duple (i->x, i->y));
if (c.x > area.x1) {
if (interpolate_line (c0, c, area.x1)) {
context->line_to (c0.x + pixel_adjust, c0.y + pixel_adjust);
}
break;
}
context->line_to (c.x + pixel_adjust, c.y + pixel_adjust);
c0 = c;
++i;
}
_right = c0;
}
bool
PolyItem::interpolate_line (Duple& c0, Duple const& c1, Coord const x)
{
if (c1.x <= c0.x) {
return false;
}
if (x < c0.x || x > c1.x) {
return false;
}
c0.y += ((x - c0.x) / (c1.x - c0.x)) * (c1.y - c0.y);
c0.x = x;
return true;
}
void
PolyItem::set (Points const& points)
{
if (_points != points) {
begin_change ();
_points = points;
set_bbox_dirty ();
end_change ();
}
}
void
PolyItem::add_point (Duple const & d)
{
begin_change ();
_points.push_back (d);
set_bbox_dirty ();
end_change ();
}
Points const&
PolyItem::get () const
{
return _points;
}
void
PolyItem::dump (ostream& o) const
{
Item::dump (o);
o << _canvas->indent () << '\t' << _points.size () << " points" << endl;
for (Points::const_iterator i = _points.begin (); i != _points.end (); ++i) {
o << _canvas->indent () << "\t\t" << i->x << ", " << i->y << endl;
}
}