luciad::MapScale Struct Reference

This class represents a map scale, a ratio of a distance on the map to the corresponding actual distance. More...

#include <luciad/maps/MapScale.h>

Public Member Functions
constexpr	MapScale (double value)
	Creates a new MapScale based on the given ratio. More...
double	getDenominator () const
	Returns the denominator of this map scale. More...
double	getValue () const
	Returns the scale value. More...
	operator double () const
	Returns this map scale value as a double value. More...
bool	operator!= (const MapScale &other) const
bool	operator< (const MapScale &other) const
bool	operator<= (const MapScale &other) const
bool	operator== (const MapScale &other) const
bool	operator> (const MapScale &other) const
bool	operator>= (const MapScale &other) const
MapScale	zoomIn (double factor) const
	Creates a new MapScale which is zoomed in with a given factor. More...
MapScale	zoomOut (double factor) const
	Creates a new MapScale which is zoomed outn with a given factor. More...

Static Public Member Functions
static constexpr MapScale	fromDenominator (double denominator)
	Creates a map scale from a denominator value. More...
static const MapScale &	maxZoomedIn ()
	The value that represents a maximally zoomed in map scale (1:0 ≈ the maximum double value) More...
static const MapScale &	maxZoomedOut ()
	The value that represents a maximally zoomed out map scale (1:inf == 0) More...

Detailed Description

This class represents a map scale, a ratio of a distance on the map to the corresponding actual distance.

For example: a map scale of 1:50000 means that 1 centimeter on a map corresponds with 500 meters on the ground.

This class gives a natural ordering to map scales, from zoomed out to zoomed in. When a part of the API takes an ordered collection as input, it must be ordered according to this natural ordering (unless stated otherwise).

In order for a Map instance to interpret MapScale values correctly, it needs to know the DPI (see Map::getDpi) value of the screen on which it is rendered.

See also the related article

Constructor & Destructor Documentation

MapScale()

constexpr luciad::MapScale::MapScale ( double  value )

inlineconstexpr

Creates a new MapScale based on the given ratio.

Parameters

value

a value that represents 1 / denominator. For example: a MapScale of 1:50000 can be created using 0.00002 (=1/50000) as value.

Exceptions

luciad::InvalidArgumentException

when the map scale is smaller than 0.

Member Function Documentation

fromDenominator()

static constexpr MapScale luciad::MapScale::fromDenominator ( double  denominator )

inlinestaticconstexpr

Creates a map scale from a denominator value.

For example when using 1:50000 as map scale, the denominator is 50000.

Parameters

denominator

the scale denominator.

Returns

a map scale that corresponds to 1:denominator

Exceptions

luciad::InvalidArgumentException

when the denominator is negative.

getDenominator()

double luciad::MapScale::getDenominator ( ) const

inline

Returns the denominator of this map scale.

For example when the Map Scale is 1:50000, this method returns 50000.

Returns

the denominator of this map scale.

getValue()

double luciad::MapScale::getValue ( ) const

inline

Returns the scale value.

Returns

the scale value.

maxZoomedIn()

static const MapScale & luciad::MapScale::maxZoomedIn ( )

static

The value that represents a maximally zoomed in map scale (1:0 ≈ the maximum double value)

maxZoomedOut()

static const MapScale & luciad::MapScale::maxZoomedOut ( )

static

The value that represents a maximally zoomed out map scale (1:inf == 0)

operator double()

luciad::MapScale::operator double ( ) const

inline

Returns this map scale value as a double value.

For example when the map scale is 1:50000, this method returns 0.00002.

Returns

this map scale value as a double value.

operator!=()

bool luciad::MapScale::operator!= ( const MapScale &  other ) const

inline

operator<()

bool luciad::MapScale::operator< ( const MapScale &  other ) const

inline

operator<=()

bool luciad::MapScale::operator<= ( const MapScale &  other ) const

inline

operator==()

bool luciad::MapScale::operator== ( const MapScale &  other ) const

inline

operator>()

bool luciad::MapScale::operator> ( const MapScale &  other ) const

inline

operator>=()

bool luciad::MapScale::operator>= ( const MapScale &  other ) const

inline

zoomIn()

MapScale luciad::MapScale::zoomIn ( double  factor ) const

inline

Creates a new MapScale which is zoomed in with a given factor.

For example, when applying this method on a 1:50000 scale, with a factor or 2, the resulting map scale will be 1:25000.

Parameters

factor

the factor using which to zoom in

Returns

a new map scale that is zoomed in using the given factor.

zoomOut()

MapScale luciad::MapScale::zoomOut ( double  factor ) const

inline

Creates a new MapScale which is zoomed outn with a given factor.

For example, when applying this method on a 1:50000 scale, with a factor or 2, the resulting map scale will be 1:100000.

Parameters

factor

the factor using which to zoom out

Returns

a new map scale that is zoomed out using the given factor.