2 Copyright (C) 2011-2013 Paul Davis
3 Author: Carl Hetherington <cth@carlh.net>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <cairomm/context.h>
22 #include "pbd/compose.h"
23 #include "canvas/line.h"
24 #include "canvas/types.h"
25 #include "canvas/debug.h"
26 #include "canvas/utils.h"
27 #include "canvas/canvas.h"
30 using namespace ArdourCanvas;
32 Line::Line (Group* parent)
40 Line::compute_bounding_box () const
44 bbox.x0 = min (_points[0].x, _points[1].x);
45 bbox.y0 = min (_points[0].y, _points[1].y);
46 bbox.x1 = max (_points[0].x, _points[1].x);
47 bbox.y1 = max (_points[0].y, _points[1].y);
49 bbox = bbox.expand (0.5 + (_outline_width / 2));
52 _bounding_box_dirty = false;
56 Line::render (Rect const & /*area*/, Cairo::RefPtr<Cairo::Context> context) const
58 setup_outline_context (context);
60 Duple p0 = item_to_window (Duple (_points[0].x, _points[0].y));
61 Duple p1 = item_to_window (Duple (_points[1].x, _points[1].y));
63 /* See Cairo FAQ on single pixel lines to understand why we add 0.5
66 context->move_to (p0.x + 0.5, p0.y + 0.5);
67 context->line_to (p1.x + 0.5, p1.y + 0.5);
72 Line::set (Duple a, Duple b)
79 _bounding_box_dirty = true;
82 DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
86 Line::set_x (Coord x0, Coord x1)
93 _bounding_box_dirty = true;
96 DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
100 Line::set_x0 (Coord x0)
106 _bounding_box_dirty = true;
109 DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
113 Line::set_y0 (Coord y0)
119 _bounding_box_dirty = true;
122 DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
126 Line::set_x1 (Coord x1)
132 _bounding_box_dirty = true;
135 DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
139 Line::set_y1 (Coord y1)
145 _bounding_box_dirty = true;
148 DEBUG_TRACE (PBD::DEBUG::CanvasItemsDirtied, "canvas item dirty: line change\n");
152 Line::covers (Duple const & point) const
154 Duple p = canvas_to_item (point);
156 /* compute area of triangle computed by the two line points and the one
157 we are being asked about. If zero (within a given tolerance), the
158 points are co-linear and the argument is on the line.
161 double area = fabs (_points[0].x * (_points[0].y - p.y)) +
162 (_points[1].x * (p.y - _points[0].y)) +
163 (p.x * (_points[0].y - _points[1].y));