1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/*
* vim: ts=4 sw=4 et tw=0 wm=0
*
* libcola - A library providing force-directed network layout using the
* stress-majorization method subject to separation constraints.
*
* Copyright (C) 2006-2008 Monash University
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library in the file LICENSE; if not,
* write to the Free Software Foundation, Inc., 59 Temple Place,
* Suite 330, Boston, MA 02111-1307 USA
*
*/
/**
* Really basic regression test of convex hull implementation
* declared in libcola/convex_hull.h
*/
#include <valarray>
#include <algorithm>
#include <libcola/convex_hull.h>
#include "graphlayouttest.h"
#include <string>
#include <iostream>
#include <cairomm/context.h>
#include <cairomm/surface.h>
/* M_PI is defined in math.h in the case of Microsoft Visual C++ */
#if defined(_MSC_VER)
#define _USE_MATH_DEFINES
#include <math.h>
#endif
using namespace std;
typedef vector<unsigned> Hull;
/**
* generates a random set of n points in X and Y.
*/
void randTest(unsigned n, valarray<double>& X, valarray<double>& Y) {
X.resize(n);
Y.resize(n);
srand(time(nullptr));
for(unsigned i=0;i<n;i++) {
X[i]=getRand(1.);
Y[i]=getRand(1.);
}
}
/**
* generates a set of 8 points (actually the vertices of two rectangles)
* which lineup horizontally. The expected hull are the lower-left and
* top-left corners of the left rectangle and the top-right/lower-right
* corners of the right rectangle.
*/
void tworects(valarray<double>& X, valarray<double>& Y, Hull& expectedHull) {
const unsigned n=8;
X.resize(n);
Y.resize(n);
X[0]=330.011898, Y[0]=203.250425;
X[1]=330.011898, Y[1]=237.250425;
X[2]=276.011898, Y[2]=237.250425;
X[3]=276.011898, Y[3]=203.250425;
X[4]=459.998300, Y[4]=203.250425;
X[5]=459.998300, Y[5]=237.250425;
X[6]=405.998300, Y[6]=237.250425;
X[7]=405.998300, Y[7]=203.250425;
unsigned hull[]={3,4,5,2};
unsigned m=sizeof(hull)/sizeof(unsigned);
expectedHull.resize(m);
copy(hull,hull+m,expectedHull.begin());
}
int drawCairo(const string& fname,
const valarray<double>& X, const valarray<double>& Y,
const Hull& hull);
int main(int argc, char** argv) {
valarray<double> X, Y;
Hull h,expectedHull;
tworects(X,Y,expectedHull);
hull::convex(X,Y,h);
printf("hull size=%d\n",h.size());
pair<Hull::iterator,Hull::iterator> r
=mismatch(h.begin(),h.end(),expectedHull.begin());
assert(r.first==h.end());
drawCairo("convex_tworects.svg",X,Y,h);
randTest(20,X,Y);
hull::convex(X,Y,h);
drawCairo("convex_hull_random.svg",X,Y,h);
return 0;
}
/***********CAIRO CODE***************************************************/
double width = 600;
double height = 400;
double border=10;
void dot(Cairo::RefPtr<Cairo::Context> & cr, double x, double y) {
cr->arc(x, y,
2., 0.0, 2.0 * M_PI);
cr->stroke();
}
double xcoord(double x) {
return border+x*width;
}
double ycoord(double y) {
return border+y*height;
}
int drawCairo(const string& fname,
const valarray<double>& Xin, const valarray<double>& Yin,
const Hull& hull) {
#ifdef CAIRO_HAS_SVG_SURFACE
unsigned n=Xin.size();
assert(Yin.size()==n);
// normalise coords to range 0-1
valarray<double> X=Xin, Y=Yin;
X-=X.min();
Y-=Y.min();
X/=X.max();
Y/=Y.max();
Cairo::RefPtr<Cairo::SvgSurface> surface =
Cairo::SvgSurface::create(fname, width+2*border, height+2*border);
Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create(surface);
cr->save(); // save the state of the context
cr->set_source_rgba(0.0, 0.0, 0.0, 0.7);
// draw a circle at each coordinate
for(unsigned i=0;i<n;i++) {
dot(cr,xcoord(X[i]),ycoord(Y[i]));
}
cr->set_source_rgba(0.0, 0.0, 0.0, 0.3);
cr->move_to(xcoord(X[hull[0]]),ycoord(Y[hull[0]]));
for(unsigned i=1;i<hull.size();i++) {
cr->line_to(xcoord(X[hull[i]]),ycoord(Y[hull[i]]));
}
cr->line_to(xcoord(X[hull[0]]),ycoord(Y[hull[0]]));
cr->stroke();
cr->set_source_rgba(0.0, 0.0, 0.0, 1.);
for(vector<unsigned>::const_iterator i=hull.begin();i!=hull.end();++i) {
unsigned j=*i;
stringstream ss;
ss<<j;
printf("p[%d]=(%f,%f)\n",j,X[j],Y[j]);
cr->move_to(xcoord(X[j]),ycoord(Y[j]));
cr->show_text(ss.str());
cr->stroke();
}
cr->restore();
cr->show_page();
cout << "Wrote SVG file \"" << fname << "\"" << endl;
return 0;
#else
cout << "You must compile cairo with SVG support for this example to work."
<< endl;
return 1;
#endif
}
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=4:softtabstop=4 :
|
