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livetrax/libs/canvas/line_set.cc

193 lines
4.1 KiB
C++

/*
* Copyright (C) 2012 Carl Hetherington <carl@carlh.net>
* Copyright (C) 2013-2017 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2015-2017 Robin Gareus <robin@gareus.org>
*
* 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 <cmath>
#include "canvas/line_set.h"
using namespace std;
using namespace ArdourCanvas;
class LineSorter {
public:
bool operator() (LineSet::Line const & a, LineSet::Line const & b) {
return a.pos < b.pos;
}
};
LineSet::LineSet (Canvas* c, Orientation o)
: Item (c)
, _extent (0)
, _orientation (o)
{
}
LineSet::LineSet (Item* parent, Orientation o)
: Item (parent)
, _extent (0)
, _orientation (o)
{
}
void
LineSet::compute_bounding_box () const
{
if (_lines.empty ()) {
_bounding_box = Rect ();
} else {
if (_orientation == Horizontal) {
double y0 = _lines.front().pos - (_lines.front().width/2.0);
double y1 = _lines.back().pos - (_lines.back().width/2.0);
if (fmod (_lines.front().width, 2.)) {
y0 -= _lines.front().width * 0.5;
}
_bounding_box = Rect (0, y0, _extent, y1);
} else {
double x0 = _lines.front().pos - _lines.front().width/2.0;
double x1 = _lines.back().pos + _lines.back().width/2.0;
if (fmod (_lines.front().width, 2.)) {
x0 -= _lines.front().width * 0.5;
}
_bounding_box = Rect (x0, 0, x1, _extent);
}
}
set_bbox_clean ();
}
void
LineSet::set_extent (Distance e)
{
begin_change ();
_extent = e;
set_bbox_dirty ();
end_change ();
}
void
LineSet::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
{
/* area is in window coordinates */
for (auto const & l : _lines) {
Rect self;
const double shift = 0.5;
if (_orientation == Horizontal) {
self = Rect (0, l.pos - (l.width/2.0), _extent, l.pos + (l.width/2.0));
if (fmod (l.width, 2.)) {
self.y0 -= shift;
}
} else {
self = Rect (l.pos - (l.width/2.0), 0, l.pos + (l.width/2.0), _extent);
if (fmod (l.width, 2.)) {
self.x0 -= shift;
}
}
self = item_to_window (self);
Rect isect = self.intersection (area);
if (!isect) {
continue;
}
Rect intersection (isect);
Gtkmm2ext::set_source_rgba (context, l.color);
context->set_line_width (l.width);
/* Not 100% sure that the computation of the invariant
* positions (y and x) below work correctly if the line width
* is not 1.0, but visual inspection suggests it is OK.
* See Cairo FAQ on single pixel lines to understand why we add 0.5
*/
if (_orientation == Horizontal) {
const double y = item_to_window (Duple (0, l.pos)).y;
context->move_to (intersection.x0, y + shift);
context->line_to (intersection.x1, y + shift);
} else {
const double x = item_to_window (Duple (l.pos, 0)).x;
context->move_to (x + shift, intersection.y0);
context->line_to (x + shift, intersection.y1);
}
context->stroke ();
}
}
void
LineSet::add_coord (Coord pos, Distance width, Gtkmm2ext::Color color)
{
_lines.push_back (Line (pos, width, color));
}
void
LineSet::begin_add ()
{
begin_change ();
}
void
LineSet::end_add ()
{
if (!_lines.empty()) {
sort (_lines.begin(), _lines.end(), LineSorter());
}
set_bbox_dirty ();
end_change ();
}
void
LineSet::clear ()
{
begin_change ();
_lines.clear ();
set_bbox_dirty ();
end_change ();
}
bool
LineSet::covers (Duple const & /*point*/) const
{
/* lines are ordered by position along primary axis, so binary search
* to find the place to start looking.
*
* XXX but not yet.
*/
return false;
}