luciad::ScreenDistance Class Reference

This class is used to represent distances between screen locations. More...

#include <luciad/input/ScreenDistance.h>

Public Member Functions
constexpr	ScreenDistance (double distance, ScreenDistanceUnit unit)
	Explicit constructor taking a distance value and a unit. More...
constexpr double	asMillimeters (double dpi, double displayScale) const
	Converting value method which returns the distance value as a double, expressed in millimeters. More...
constexpr double	asPixels (double dpi, double displayScale) const
	Converting value method which returns the distance value as a double, expressed in device independent pixels. More...
constexpr ScreenDistanceUnit	getUnit () const
constexpr double	getValue () const

Static Public Member Functions
static constexpr ScreenDistance	millimeters (double millimeters)
	Utility factory method for constructing a ScreenDistance expressed in millimeters. More...
static constexpr ScreenDistance	pixels (double pixels)
	Utility factory method for constructing a ScreenDistance expressed in device independent pixels. More...

Detailed Description

This class is used to represent distances between screen locations.

It consists of a unit (expressed as a ScreenDistanceUnit) and the distance value.

This class contains utility methods for converting distance values from millimeters to pixels or vice-versa, by taking DPI and display scale into account (see ScreenDistance#asPixels and ScreenDistance#asMillimeters).

Related article: Support high-resolution (HiDPI) displays.

Since

2022.0

Constructor & Destructor Documentation

ScreenDistance()

constexpr luciad::ScreenDistance::ScreenDistance ( double  distance, ScreenDistanceUnit  unit  )

inlineconstexpr

Explicit constructor taking a distance value and a unit.

Parameters

distance	the distance, expressed in the chosen unit.
unit	either ScreenDistanceUnit::Pixels or ScreenDistanceUnit::Millimeters.

Member Function Documentation

asMillimeters()

constexpr double luciad::ScreenDistance::asMillimeters ( double  dpi, double  displayScale  ) const

inlineconstexpr

Converting value method which returns the distance value as a double, expressed in millimeters.

In order to make any possible conversion from device independent pixels to millimeters, the display DPI and display scale must be provided. If the stored unit is ScreenDistanceUnit::Millimeters, the currently stored value is returned.

Parameters

dpi	the display density in dots per inch
displayScale	the display scale

Returns

the screen distance in millimeters, as a double.

asPixels()

constexpr double luciad::ScreenDistance::asPixels ( double  dpi, double  displayScale  ) const

inlineconstexpr

Converting value method which returns the distance value as a double, expressed in device independent pixels.

In order to make any possible conversion from millimeters to pixels, the display DPI and display scale must be provided. If the stored unit is ScreenDistanceUnit::Pixels, the currently stored value is returned.

Parameters

dpi	the display density in dots per inch
displayScale	the display scale

Returns

the screen distance in device independent pixels, as a double.

getUnit()

constexpr ScreenDistanceUnit luciad::ScreenDistance::getUnit ( ) const

inlineconstexpr

Returns

the screen distance unit.

getValue()

constexpr double luciad::ScreenDistance::getValue ( ) const

inlineconstexpr

Returns

the screen distance value, as a double.

millimeters()

static constexpr ScreenDistance luciad::ScreenDistance::millimeters ( double  millimeters )

inlinestaticconstexpr

Utility factory method for constructing a ScreenDistance expressed in millimeters.

Parameters

millimeters

the distance in millimeters.

Returns

a ScreenDistance instance taking the passed value and expressed in millimeters.

pixels()

static constexpr ScreenDistance luciad::ScreenDistance::pixels ( double  pixels )

inlinestaticconstexpr

Utility factory method for constructing a ScreenDistance expressed in device independent pixels.

Parameters

pixels

the distance in device independent pixels.

Returns

a ScreenDistance instance taking the passed value and expressed in device independent pixels.