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
|
/*
* This file is part of NumptyPhysics
* Copyright (C) 2008 Tim Edmonds
*
* 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 3 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.
*
*/
#include <cstring>
#include "Path.h"
static float32 calcDistanceToLine( const Vec2& pt,
const Vec2& l1, const Vec2& l2,
bool* withinLine=NULL )
{
b2Vec2 l = l2 - l1;
b2Vec2 w = pt - l1;
float32 mag = l.Normalize();
float32 dist = b2Cross( w, l );
if ( withinLine ) {
float32 dot = b2Dot( l, w );
*withinLine = ( dot >= 0.0f && dot <= mag );
}
return b2Abs( dist );
}
static float32 calcDistance( const Vec2& l1, const Vec2& l2 )
{
return b2Vec2(l1-l2).Length();
}
float32 Segment::distanceTo( const Vec2& p )
{
bool withinLine;
float32 d = calcDistanceToLine( p, m_p1, m_p2, &withinLine );
if ( !(m_p1 == m_p2) && withinLine ) {
return d;
} else {
return b2Min( calcDistance( p, m_p2 ), calcDistance( p, m_p1 ) );
}
}
Path::Path() : Array<Vec2>() {}
Path::Path( int n, Vec2* p ) : Array<Vec2>(n, p) {}
Path::Path( const char *s )
{
float32 x,y;
while ( sscanf( s, "%f,%f", &x, &y )==2) {
append( Vec2((int)x,(int)y) );
while ( *s && *s!=' ' && *s!='\t' ) s++;
while ( *s==' ' || *s=='\t' ) s++;
}
}
void Path::makeRelative()
{
for (int i=size()-1; i>=0; i--)
at(i)-=at(0);
}
Path& Path::translate(const Vec2& xlate)
{
for (int i=0;i<size();i++)
at(i) += xlate;
return *this;
}
Path& Path::rotate(const b2Mat22& rot)
{
float32 j1 = rot.col1.x;
float32 k1 = rot.col1.y;
float32 j2 = rot.col2.x;
float32 k2 = rot.col2.y;
Vec2 v;
for (int i=0;i<size();i++) {
//at(i) = b2Mul( rot, at(i) );
at(i) = Vec2( j1 * at(i).x + j2 * at(i).y,
k1 * at(i).x + k2 * at(i).y );
}
return *this;
}
Path& Path::scale(float32 factor)
{
for (int i=0;i<size();i++) {
at(i).x = at(i).x * factor;
at(i).y = at(i).y * factor;
}
return *this;
}
void Path::simplify( float32 threshold )
{
bool keepflags[size()];
memset( &keepflags[0], 0, sizeof(keepflags) );
keepflags[0] = keepflags[size()-1] = true;
simplifySub( 0, size()-1, threshold, &keepflags[0] );
int k=0;
for ( int i=0; i<size(); i++ ) {
if ( keepflags[i] ) {
at(k++) = at(i);
}
}
//printf("simplify %f %dpts to %dpts\n",threshold,size(),k);
trim( size() - k );
// remove duplicate points (shouldn't be any)
for ( int i=size()-1; i>0; i-- ) {
if ( at(i) == at(i-1) ) {
//printf("alert: duplicate pt %d == %d!\n",i,i-1);
erase( i );
}
}
}
void Path::simplifySub( int first, int last, float32 threshold, bool* keepflags )
{
float32 furthestDist = threshold;
int furthestIndex = 0;
if ( last - first > 1 ) {
Segment s( at(first), at(last) );
for ( int i=first+1; i<last; i++ ) {
float32 d = s.distanceTo( at(i) );
if ( d > furthestDist ) {
furthestDist = d;
furthestIndex = i;
}
}
if ( furthestIndex != 0 ) {
keepflags[furthestIndex] = true;
simplifySub( first, furthestIndex, threshold, keepflags );
simplifySub( furthestIndex, last, threshold, keepflags );
}
}
}
Rect Path::bbox() const
{
Rect r( at(0), at(0) );
for ( int i=1; i<size(); i++ ) {
r.expand( at(i) );
}
return r;
}
|
