QGIS/src/core/qgspoint.cpp
2016-12-09 08:13:48 +10:00

512 lines
14 KiB
C++

/***************************************************************************
qgspoint.cpp - description
-------------------
begin : Sat Jun 22 2002
copyright : (C) 2002 by Gary E.Sherman
email : sherman at mrcc.com
***************************************************************************/
/***************************************************************************
* *
* 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 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
#include "qgspoint.h"
#include "qgis.h"
#include <cmath>
#include <QTextStream>
#include <QObject> // for tr()
#include "qgsexception.h"
//
// QgsVector
//
QgsVector::QgsVector()
: mX( 0.0 )
, mY( 0.0 )
{
}
QgsVector::QgsVector( double x, double y )
: mX( x )
, mY( y )
{
}
QgsVector QgsVector::operator-() const
{
return QgsVector( -mX, -mY );
}
QgsVector QgsVector::operator*( double scalar ) const
{
return QgsVector( mX * scalar, mY * scalar );
}
QgsVector QgsVector::operator/( double scalar ) const
{
return *this * ( 1.0 / scalar );
}
double QgsVector::operator*( QgsVector v ) const
{
return mX * v.mX + mY * v.mY;
}
QgsVector QgsVector::operator+( QgsVector other ) const
{
return QgsVector( mX + other.mX, mY + other.mY );
}
QgsVector& QgsVector::operator+=( QgsVector other )
{
mX += other.mX;
mY += other.mY;
return *this;
}
QgsVector QgsVector::operator-( QgsVector other ) const
{
return QgsVector( mX - other.mX, mY - other.mY );
}
QgsVector& QgsVector::operator-=( QgsVector other )
{
mX -= other.mX;
mY -= other.mY;
return *this;
}
double QgsVector::length() const
{
return sqrt( mX * mX + mY * mY );
}
double QgsVector::x() const
{
return mX;
}
double QgsVector::y() const
{
return mY;
}
QgsVector QgsVector::perpVector() const
{
return QgsVector( -mY, mX );
}
double QgsVector::angle() const
{
double ang = atan2( mY, mX );
return ang < 0.0 ? ang + 2.0 * M_PI : ang;
}
double QgsVector::angle( QgsVector v ) const
{
return v.angle() - angle();
}
QgsVector QgsVector::rotateBy( double rot ) const
{
double ang = atan2( mY, mX ) + rot;
double len = length();
return QgsVector( len * cos( ang ), len * sin( ang ) );
}
QgsVector QgsVector::normalized() const
{
double len = length();
if ( len == 0.0 )
{
throw QgsException( QStringLiteral( "normalized vector of null vector undefined" ) );
}
return *this / len;
}
//
// QgsPoint
//
QgsPoint::QgsPoint( const QgsPoint& p )
{
m_x = p.x();
m_y = p.y();
}
QPointF QgsPoint::toQPointF() const
{
return QPointF( m_x, m_y );
}
QString QgsPoint::toString() const
{
QString rep;
QTextStream ot( &rep );
ot.setRealNumberPrecision( 12 );
ot << m_x << ", " << m_y;
return rep;
}
QString QgsPoint::toString( int thePrecision ) const
{
QString x = qIsFinite( m_x ) ? QString::number( m_x, 'f', thePrecision ) : QObject::tr( "infinite" );
QString y = qIsFinite( m_y ) ? QString::number( m_y, 'f', thePrecision ) : QObject::tr( "infinite" );
return QStringLiteral( "%1,%2" ).arg( x, y );
}
QString QgsPoint::toDegreesMinutesSeconds( int thePrecision, const bool useSuffix, const bool padded ) const
{
//first, limit longitude to -360 to 360 degree range
double myWrappedX = fmod( m_x, 360.0 );
//next, wrap around longitudes > 180 or < -180 degrees, so that eg "190E" -> "170W"
if ( myWrappedX > 180.0 )
{
myWrappedX = myWrappedX - 360.0;
}
else if ( myWrappedX < -180.0 )
{
myWrappedX = myWrappedX + 360.0;
}
//first, limit latitude to -180 to 180 degree range
double myWrappedY = fmod( m_y, 180.0 );
//next, wrap around latitudes > 90 or < -90 degrees, so that eg "110S" -> "70N"
if ( myWrappedY > 90.0 )
{
myWrappedY = myWrappedY - 180.0;
}
else if ( myWrappedY < -90.0 )
{
myWrappedY = myWrappedY + 180.0;
}
int myDegreesX = int( qAbs( myWrappedX ) );
double myFloatMinutesX = double(( qAbs( myWrappedX ) - myDegreesX ) * 60 );
int myIntMinutesX = int( myFloatMinutesX );
double mySecondsX = double( myFloatMinutesX - myIntMinutesX ) * 60;
int myDegreesY = int( qAbs( myWrappedY ) );
double myFloatMinutesY = double(( qAbs( myWrappedY ) - myDegreesY ) * 60 );
int myIntMinutesY = int( myFloatMinutesY );
double mySecondsY = double( myFloatMinutesY - myIntMinutesY ) * 60;
//make sure rounding to specified precision doesn't create seconds >= 60
if ( qRound( mySecondsX * pow( 10.0, thePrecision ) ) >= 60 * pow( 10.0, thePrecision ) )
{
mySecondsX = qMax( mySecondsX - 60, 0.0 );
myIntMinutesX++;
if ( myIntMinutesX >= 60 )
{
myIntMinutesX -= 60;
myDegreesX++;
}
}
if ( qRound( mySecondsY * pow( 10.0, thePrecision ) ) >= 60 * pow( 10.0, thePrecision ) )
{
mySecondsY = qMax( mySecondsY - 60, 0.0 );
myIntMinutesY++;
if ( myIntMinutesY >= 60 )
{
myIntMinutesY -= 60;
myDegreesY++;
}
}
QString myXHemisphere;
QString myYHemisphere;
QString myXSign;
QString myYSign;
if ( useSuffix )
{
myXHemisphere = myWrappedX < 0 ? QObject::tr( "W" ) : QObject::tr( "E" );
myYHemisphere = myWrappedY < 0 ? QObject::tr( "S" ) : QObject::tr( "N" );
}
else
{
if ( myWrappedX < 0 )
{
myXSign = QObject::tr( "-" );
}
if ( myWrappedY < 0 )
{
myYSign = QObject::tr( "-" );
}
}
//check if coordinate is all zeros for the specified precision, and if so,
//remove the sign and hemisphere strings
if ( myDegreesX == 0 && myIntMinutesX == 0 && qRound( mySecondsX * pow( 10.0, thePrecision ) ) == 0 )
{
myXSign = QString();
myXHemisphere = QString();
}
if ( myDegreesY == 0 && myIntMinutesY == 0 && qRound( mySecondsY * pow( 10.0, thePrecision ) ) == 0 )
{
myYSign = QString();
myYHemisphere = QString();
}
//also remove directional prefix from 180 degree longitudes
if ( myDegreesX == 180 && myIntMinutesX == 0 && qRound( mySecondsX * pow( 10.0, thePrecision ) ) == 0 )
{
myXHemisphere = QString();
}
//pad minutes with leading digits if required
QString myMinutesX = padded ? QStringLiteral( "%1" ).arg( myIntMinutesX, 2, 10, QChar( '0' ) ) : QString::number( myIntMinutesX );
QString myMinutesY = padded ? QStringLiteral( "%1" ).arg( myIntMinutesY, 2, 10, QChar( '0' ) ) : QString::number( myIntMinutesY );
//pad seconds with leading digits if required
int digits = 2 + ( thePrecision == 0 ? 0 : 1 + thePrecision ); //1 for decimal place if required
QString myStrSecondsX = padded ? QStringLiteral( "%1" ).arg( mySecondsX, digits, 'f', thePrecision, QChar( '0' ) ) : QString::number( mySecondsX, 'f', thePrecision );
QString myStrSecondsY = padded ? QStringLiteral( "%1" ).arg( mySecondsY, digits, 'f', thePrecision, QChar( '0' ) ) : QString::number( mySecondsY, 'f', thePrecision );
QString rep = myXSign + QString::number( myDegreesX ) + QChar( 176 ) +
myMinutesX + QChar( 0x2032 ) +
myStrSecondsX + QChar( 0x2033 ) +
myXHemisphere + ',' +
myYSign + QString::number( myDegreesY ) + QChar( 176 ) +
myMinutesY + QChar( 0x2032 ) +
myStrSecondsY + QChar( 0x2033 ) +
myYHemisphere;
return rep;
}
QString QgsPoint::toDegreesMinutes( int thePrecision, const bool useSuffix, const bool padded ) const
{
//first, limit longitude to -360 to 360 degree range
double myWrappedX = fmod( m_x, 360.0 );
//next, wrap around longitudes > 180 or < -180 degrees, so that eg "190E" -> "170W"
if ( myWrappedX > 180.0 )
{
myWrappedX = myWrappedX - 360.0;
}
else if ( myWrappedX < -180.0 )
{
myWrappedX = myWrappedX + 360.0;
}
int myDegreesX = int( qAbs( myWrappedX ) );
double myFloatMinutesX = double(( qAbs( myWrappedX ) - myDegreesX ) * 60 );
int myDegreesY = int( qAbs( m_y ) );
double myFloatMinutesY = double(( qAbs( m_y ) - myDegreesY ) * 60 );
//make sure rounding to specified precision doesn't create minutes >= 60
if ( qRound( myFloatMinutesX * pow( 10.0, thePrecision ) ) >= 60 * pow( 10.0, thePrecision ) )
{
myFloatMinutesX = qMax( myFloatMinutesX - 60, 0.0 );
myDegreesX++;
}
if ( qRound( myFloatMinutesY * pow( 10.0, thePrecision ) ) >= 60 * pow( 10.0, thePrecision ) )
{
myFloatMinutesY = qMax( myFloatMinutesY - 60, 0.0 );
myDegreesY++;
}
QString myXHemisphere;
QString myYHemisphere;
QString myXSign;
QString myYSign;
if ( useSuffix )
{
myXHemisphere = myWrappedX < 0 ? QObject::tr( "W" ) : QObject::tr( "E" );
myYHemisphere = m_y < 0 ? QObject::tr( "S" ) : QObject::tr( "N" );
}
else
{
if ( myWrappedX < 0 )
{
myXSign = QObject::tr( "-" );
}
if ( m_y < 0 )
{
myYSign = QObject::tr( "-" );
}
}
//check if coordinate is all zeros for the specified precision, and if so,
//remove the sign and hemisphere strings
if ( myDegreesX == 0 && qRound( myFloatMinutesX * pow( 10.0, thePrecision ) ) == 0 )
{
myXSign = QString();
myXHemisphere = QString();
}
if ( myDegreesY == 0 && qRound( myFloatMinutesY * pow( 10.0, thePrecision ) ) == 0 )
{
myYSign = QString();
myYHemisphere = QString();
}
//also remove directional prefix from 180 degree longitudes
if ( myDegreesX == 180 && qRound( myFloatMinutesX * pow( 10.0, thePrecision ) ) == 0 )
{
myXHemisphere = QString();
}
//pad minutes with leading digits if required
int digits = 2 + ( thePrecision == 0 ? 0 : 1 + thePrecision ); //1 for decimal place if required
QString myStrMinutesX = padded ? QStringLiteral( "%1" ).arg( myFloatMinutesX, digits, 'f', thePrecision, QChar( '0' ) ) : QString::number( myFloatMinutesX, 'f', thePrecision );
QString myStrMinutesY = padded ? QStringLiteral( "%1" ).arg( myFloatMinutesY, digits, 'f', thePrecision, QChar( '0' ) ) : QString::number( myFloatMinutesY, 'f', thePrecision );
QString rep = myXSign + QString::number( myDegreesX ) + QChar( 176 ) +
myStrMinutesX + QChar( 0x2032 ) +
myXHemisphere + ',' +
myYSign + QString::number( myDegreesY ) + QChar( 176 ) +
myStrMinutesY + QChar( 0x2032 ) +
myYHemisphere;
return rep;
}
QString QgsPoint::wellKnownText() const
{
return QStringLiteral( "POINT(%1 %2)" ).arg( qgsDoubleToString( m_x ), qgsDoubleToString( m_y ) );
}
double QgsPoint::sqrDist( double x, double y ) const
{
return ( m_x - x ) * ( m_x - x ) + ( m_y - y ) * ( m_y - y );
}
double QgsPoint::sqrDist( const QgsPoint& other ) const
{
return sqrDist( other.x(), other.y() );
}
double QgsPoint::distance( double x, double y ) const
{
return sqrt( sqrDist( x, y ) );
}
double QgsPoint::distance( const QgsPoint& other ) const
{
return sqrt( sqrDist( other ) );
}
double QgsPoint::azimuth( const QgsPoint& other ) const
{
double dx = other.x() - m_x;
double dy = other.y() - m_y;
return ( atan2( dx, dy ) * 180.0 / M_PI );
}
QgsPoint QgsPoint::project( double distance, double bearing ) const
{
double rads = bearing * M_PI / 180.0;
double dx = distance * sin( rads );
double dy = distance * cos( rads );
return QgsPoint( m_x + dx, m_y + dy );
}
bool QgsPoint::compare( const QgsPoint &other, double epsilon ) const
{
return ( qgsDoubleNear( m_x, other.x(), epsilon ) && qgsDoubleNear( m_y, other.y(), epsilon ) );
}
// operators
bool QgsPoint::operator==( const QgsPoint & other )
{
if ( qgsDoubleNear( m_x, other.x() ) && qgsDoubleNear( m_y, other.y() ) )
return true;
else
return false;
}
bool QgsPoint::operator!=( const QgsPoint & other ) const
{
if ( qgsDoubleNear( m_x, other.x() ) && qgsDoubleNear( m_y, other.y() ) )
return false;
else
return true;
}
QgsPoint & QgsPoint::operator=( const QgsPoint & other )
{
if ( &other != this )
{
m_x = other.x();
m_y = other.y();
}
return *this;
}
void QgsPoint::multiply( double scalar )
{
m_x *= scalar;
m_y *= scalar;
}
int QgsPoint::onSegment( const QgsPoint& a, const QgsPoint& b ) const
{
//algorithm from 'graphics GEMS', A. Paeth: 'A Fast 2D Point-on-line test'
if (
qAbs(( b.y() - a.y() ) *( m_x - a.x() ) - ( m_y - a.y() ) *( b.x() - a.x() ) )
>= qMax( qAbs( b.x() - a.x() ), qAbs( b.y() - a.y() ) )
)
{
return 0;
}
if (( b.x() < a.x() && a.x() < m_x ) || ( b.y() < a.y() && a.y() < m_y ) )
{
return 1;
}
if (( m_x < a.x() && a.x() < b.x() ) || ( m_y < a.y() && a.y() < b.y() ) )
{
return 1;
}
if (( a.x() < b.x() && b.x() < m_x ) || ( a.y() < b.y() && b.y() < m_y ) )
{
return 3;
}
if (( m_x < b.x() && b.x() < a.x() ) || ( m_y < b.y() && b.y() < a.y() ) )
{
return 3;
}
return 2;
}
double QgsPoint::sqrDistToSegment( double x1, double y1, double x2, double y2, QgsPoint& minDistPoint, double epsilon ) const
{
double nx, ny; //normal vector
nx = y2 - y1;
ny = -( x2 - x1 );
double t;
t = ( m_x * ny - m_y * nx - x1 * ny + y1 * nx ) / (( x2 - x1 ) * ny - ( y2 - y1 ) * nx );
if ( t < 0.0 )
{
minDistPoint.setX( x1 );
minDistPoint.setY( y1 );
}
else if ( t > 1.0 )
{
minDistPoint.setX( x2 );
minDistPoint.setY( y2 );
}
else
{
minDistPoint.setX( x1 + t *( x2 - x1 ) );
minDistPoint.setY( y1 + t *( y2 - y1 ) );
}
double dist = sqrDist( minDistPoint );
//prevent rounding errors if the point is directly on the segment
if ( qgsDoubleNear( dist, 0.0, epsilon ) )
{
minDistPoint.setX( m_x );
minDistPoint.setY( m_y );
return 0.0;
}
return dist;
}