1 // -*- C++ -*-
2
3 /*
4 * Gnome Chemistry Utils
5 * gccv/poly-line.cc
6 *
7 * Copyright (C) 2008-2012 Jean Bréfort <jean.brefort@normalesup.org>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 3 of the
12 * License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
22 * USA
23 */
24
25 #include "config.h"
26 #include "poly-line.h"
27 #include <cmath>
28
29 using namespace std;
30
31 namespace gccv {
32
PolyLine(Canvas * canvas,list<Point> & points)33 PolyLine::PolyLine (Canvas *canvas, list <Point> &points):
34 LineItem (canvas)
35 {
36 SetPoints (points);
37 }
38
PolyLine(Group * parent,list<Point> & points,ItemClient * client)39 PolyLine::PolyLine (Group *parent, list <Point> &points, ItemClient *client):
40 LineItem (parent, client)
41 {
42 SetPoints (points);
43 }
44
~PolyLine()45 PolyLine::~PolyLine ()
46 {
47 }
48
SetPoints(list<Point> & points)49 void PolyLine::SetPoints (list <Point> &points)
50 {
51 Invalidate ();
52 m_Points = points;
53 BoundsChanged ();
54 Invalidate ();
55 }
56
Distance(double x,double y,Item ** item) const57 double PolyLine::Distance (double x, double y, Item **item) const
58 {
59 list <Point>::const_iterator i = m_Points.begin (), end = m_Points.end ();
60 if (i == end)
61 return G_MAXDOUBLE;
62 double x0 = (*i).x, y0 = (*i).y, x1, y1;
63 double lw = GetLineWidth () / 2.;
64 double result = G_MAXDOUBLE, d, dx, dy, dx1, dy1, xx, yy, length;
65 // we do not take miter limits into account
66 if (item)
67 *item = const_cast <PolyLine *> (this);
68 for (i++; i != end; i++) {
69 x1 = (*i).x;
70 y1 = (*i).y;
71 dx = x1 - x0;
72 dy = y1 - y0;
73 dx1 = x - x0;
74 dy1 = y - y0;
75 length = sqrt (dx * dx + dy * dy);
76 if (length == 0.)
77 d = sqrt (dx1 * dx1 + dy1 * dy1);
78 else {
79 xx = (dx1 * dx + dy1 * dy) / length;
80 yy = (dx1 * dy - dy1 * dx) / length;
81 if (xx < 0.) {
82 if (fabs (yy) < lw)
83 d = fabs (xx);
84 else {
85 yy = fabs (yy) - lw;
86 d = sqrt (xx * xx + yy * yy);
87 }
88 } else if (xx > length) {
89 xx -= length;
90 if (fabs (yy) < lw)
91 d = fabs (xx);
92 else {
93 yy = fabs (yy) - lw;
94 d = sqrt (xx * xx + yy * yy);
95 }
96 } else {
97 if (fabs (yy) <= lw)
98 return 0;
99 else
100 d = fabs (yy) - lw;
101 }
102 }
103 if (d < result)
104 result = d;
105 x0 = x1;
106 y0 = y1;
107 }
108 return result;
109 }
110
Draw(cairo_t * cr,G_GNUC_UNUSED bool is_vector) const111 void PolyLine::Draw (cairo_t *cr, G_GNUC_UNUSED bool is_vector) const
112 {
113 GOColor color = GetEffectiveLineColor ();
114 if (color != 0) {
115 cairo_set_line_width (cr, GetLineWidth ());
116 list <Point>::const_iterator i = m_Points.begin (), end = m_Points.end ();
117 if (i == end)
118 return;
119 cairo_move_to (cr, (*i).x, (*i).y);
120 for (i++; i != end; i++)
121 cairo_line_to (cr, (*i).x, (*i).y);
122 cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
123 cairo_set_line_join (cr, CAIRO_LINE_JOIN_MITER);
124 cairo_set_miter_limit (cr, 10.);
125 cairo_set_source_rgba (cr, GO_COLOR_TO_CAIRO (color));
126 cairo_stroke (cr);
127 }
128 }
129
UpdateBounds()130 void PolyLine::UpdateBounds ()
131 {
132 // This code might be off by a little thing because of miter limits.
133 list <Point>::const_iterator i = m_Points.begin (), end = m_Points.end ();
134 if (i == end)
135 return;
136 m_x0 = m_x1 = (*i).x;
137 m_y0 = m_y1 = (*i).y;
138 for (i++; i != end; i++) {
139 if ((*i).x < m_x0)
140 m_x0 = (*i).x;
141 else if ((*i).x > m_x1)
142 m_x1 = (*i).x;
143 if ((*i).y < m_y0)
144 m_y0 = (*i).y;
145 else if ((*i).y > m_y1)
146 m_y1 = (*i).y;
147 }
148 double lw = GetLineWidth () / 2.;
149 m_x0 -= lw;
150 m_x1 += lw;
151 m_y0 -= lw;
152 m_y1 += lw;
153 Item::UpdateBounds ();
154 }
155
Move(double x,double y)156 void PolyLine::Move (double x, double y)
157 {
158 Invalidate ();
159 list <Point>::iterator i, end = m_Points.end ();
160 for (i = m_Points.begin (); i != end; i++) {
161 (*i).x += x;
162 (*i).y += y;
163 }
164 BoundsChanged ();
165 Invalidate ();
166 }
167
168 }
169