source: ntrip/trunk/BNC/qwt/qwt_point_polar.cpp@ 5423

Last change on this file since 5423 was 4271, checked in by mervart, 12 years ago
File size: 2.9 KB
Line 
1/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
2 * QwtPolar Widget Library
3 * Copyright (C) 2008 Uwe Rathmann
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the Qwt License, Version 1.0
7 *****************************************************************************/
8
9#include "qwt_point_polar.h"
10#include "qwt_math.h"
11
12#if QT_VERSION < 0x040601
13#define qAtan2(y, x) ::atan2(y, x)
14#endif
15
16/*!
17 Convert and assign values from a point in Cartesian coordinates
18
19 \param p Point in Cartesian coordinates
20 \sa setPoint(), toPoint()
21*/
22QwtPointPolar::QwtPointPolar( const QPointF &p )
23{
24 d_radius = qSqrt( qwtSqr( p.x() ) + qwtSqr( p.y() ) );
25 d_azimuth = qAtan2( p.y(), p.x() );
26}
27
28/*!
29 Convert and assign values from a point in Cartesian coordinates
30 \param p Point in Cartesian coordinates
31*/
32void QwtPointPolar::setPoint( const QPointF &p )
33{
34 d_radius = qSqrt( qwtSqr( p.x() ) + qwtSqr( p.y() ) );
35 d_azimuth = qAtan2( p.y(), p.x() );
36}
37
38/*!
39 Convert and return values in Cartesian coordinates
40
41 \note Invalid or null points will be returned as QPointF(0.0, 0.0)
42 \sa isValid(), isNull()
43*/
44QPointF QwtPointPolar::toPoint() const
45{
46 if ( d_radius <= 0.0 )
47 return QPointF( 0.0, 0.0 );
48
49 const double x = d_radius * qCos( d_azimuth );
50 const double y = d_radius * qSin( d_azimuth );
51
52 return QPointF( x, y );
53}
54
55/*!
56 Returns true if point1 is equal to point2; otherwise returns false.
57
58 Two points are equal to each other if radius and
59 azimuth-coordinates are the same. Points are not equal, when
60 the azimuth differs, but other.azimuth() == azimuth() % (2 * PI).
61
62 \sa normalized()
63*/
64bool QwtPointPolar::operator==( const QwtPointPolar &other ) const
65{
66 return d_radius == other.d_radius && d_azimuth == other.d_azimuth;
67}
68
69/*!
70 Returns true if point1 is not equal to point2; otherwise returns false.
71
72 Two points are equal to each other if radius and
73 azimuth-coordinates are the same. Points are not equal, when
74 the azimuth differs, but other.azimuth() == azimuth() % (2 * PI).
75
76 \sa normalized()
77*/
78bool QwtPointPolar::operator!=( const QwtPointPolar &other ) const
79{
80 return d_radius != other.d_radius || d_azimuth != other.d_azimuth;
81}
82
83/*!
84 Normalize radius and azimuth
85
86 When the radius is < 0.0 it is set to 0.0. The azimuth is
87 a value >= 0.0 and < 2 * M_PI.
88*/
89QwtPointPolar QwtPointPolar::normalized() const
90{
91 const double radius = qMax( d_radius, 0.0 );
92
93 double azimuth = d_azimuth;
94 if ( azimuth < -2.0 * M_PI || azimuth >= 2 * M_PI )
95 azimuth = ::fmod( d_azimuth, 2 * M_PI );
96
97 if ( azimuth < 0.0 )
98 azimuth += 2 * M_PI;
99
100 return QwtPointPolar( azimuth, radius );
101}
102
103#ifndef QT_NO_DEBUG_STREAM
104
105QDebug operator<<( QDebug debug, const QwtPointPolar &point )
106{
107 debug.nospace() << "QwtPointPolar("
108 << point.azimuth() << "," << point.radius() << ")";
109
110 return debug.space();
111}
112
113#endif
114
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