Provide a set of methods used to draw sky objects taking into account eyes adaptation, zoom level, instrument model and artificially set magnitude limits.

#include <StelSkyDrawer.hpp>

Public Slots
void	setRelativeStarScale (double b=1.0)
	Set the way brighter stars will look bigger as the fainter ones.

double	getRelativeStarScale () const
	Get the way brighter stars will look bigger as the fainter ones.

void	setAbsoluteStarScale (double b=1.0)
	Set the absolute star brightness scale.

double	getAbsoluteStarScale () const
	Get the absolute star brightness scale.

void	setTwinkleAmount (double b)
	Set source twinkle amount.

double	getTwinkleAmount () const
	Get source twinkle amount.

void	setFlagTwinkle (bool b)
	Set flag for source twinkling.

bool	getFlagTwinkle () const
	Get flag for source twinkling.

void	setFlagForcedTwinkle (bool b)
	Set flag for enable twinkling of stars without atmosphere. More...

bool	getFlagForcedTwinkle () const
	Get flag for enable twinkling of stars without atmosphere. More...

void	setBortleScaleIndex (int index)
	Set the parameters so that the stars disappear at about the limit given by the bortle scale The limit is valid only at a given zoom level (around 60 deg) More...

int	getBortleScaleIndex () const
	Get the current Bortle scale index. More...

float	getNELMFromBortleScale () const
	Get the average NELM for current Bortle scale index: Class 1 = NELM 7.6-8.0; average NELM is 7.8 Class 2 = NELM 7.1-7.5; average NELM is 7.3 Class 3 = NELM 6.6-7.0; average NELM is 6.8 Class 4 = NELM 6.1-6.5; average NELM is 6.3 Class 5 = NELM 5.6-6.0; average NELM is 5.8 Class 6 = NELM 5.1-5.5; average NELM is 5.3 Class 7 = NELM 4.6-5.0; average NELM is 4.8 Class 8 = NELM 4.1-4.5; average NELM is 4.3 Class 9 = NELM 4.0.

static float	getNELMFromBortleScale (int idx)
	Get the average NELM for given Bortle scale index [1..9] Class 1 = NELM 7.6-8.0; average NELM is 7.8 Class 2 = NELM 7.1-7.5; average NELM is 7.3 Class 3 = NELM 6.6-7.0; average NELM is 6.8 Class 4 = NELM 6.1-6.5; average NELM is 6.3 Class 5 = NELM 5.6-6.0; average NELM is 5.8 Class 6 = NELM 5.1-5.5; average NELM is 5.3 Class 7 = NELM 4.6-5.0; average NELM is 4.8 Class 8 = NELM 4.1-4.5; average NELM is 4.3 Class 9 = NELM 4.0. More...

void	setFlagDrawBigStarHalo (bool b)
	Set flag for drawing a halo around bright stars.

bool	getFlagDrawBigStarHalo () const
	Get flag for drawing a halo around bright stars.

float	getLimitMagnitude () const
	Get the magnitude of the currently faintest visible point source It depends on the zoom level, on the eye adapation and on the point source rendering parameters. More...

void	setFlagStarMagnitudeLimit (bool b)
	Toggle the application of user-defined star magnitude limit. More...

bool	getFlagStarMagnitudeLimit () const

void	setFlagNebulaMagnitudeLimit (bool b)
	Toggle the application of user-defined deep-sky object magnitude limit. More...

bool	getFlagNebulaMagnitudeLimit () const

void	setFlagPlanetMagnitudeLimit (bool b)
	Toggle the application of user-defined solar system object magnitude limit. More...

bool	getFlagPlanetMagnitudeLimit () const

double	getCustomStarMagnitudeLimit () const
	Get the value used for forced star magnitude limiting.

void	setCustomStarMagnitudeLimit (double limit)
	Sets a lower limit for star magnitudes (anything fainter is ignored). More...

double	getCustomNebulaMagnitudeLimit () const
	Get the value used for forced nebula magnitude limiting.

void	setCustomNebulaMagnitudeLimit (double limit)
	Sets a lower limit for nebula magnitudes (anything fainter is ignored). More...

double	getCustomPlanetMagnitudeLimit () const
	Get the value used for forced solar system object magnitude limiting.

void	setCustomPlanetMagnitudeLimit (double limit)
	Sets a lower limit for solar system object magnitudes (anything fainter is ignored). More...

float	getLimitLuminance () const
	Get the luminance of the faintest visible object (e.g. More...

void	setFlagLuminanceAdaptation (bool b)
	Set the value of the eye adaptation flag.

bool	getFlagLuminanceAdaptation () const
	Get the current value of eye adaptation flag.

void	setDaylightLabelThreshold (double t)
	Set the label brightness threshold.

double	getDaylightLabelThreshold () const
	Get the current label brightness threshold.

double	getWorldAdaptationLuminance () const
	Return a brightness value based on objects in view (sky, sun, moon, ...)

void	setFlagHasAtmosphere (bool b)
	Informing the drawer whether atmosphere is displayed. More...

bool	getFlagHasAtmosphere () const
	This is used to decide whether to apply refraction/extinction before rendering point sources et al.

void	setExtinctionCoefficient (double extCoeff)
	Set extinction coefficient, mag/airmass (for extinction).

double	getExtinctionCoefficient () const
	Get extinction coefficient, mag/airmass (for extinction).

void	setAtmosphereTemperature (double celsius)
	Set atmospheric (ground) temperature in deg celsius (for refraction).

double	getAtmosphereTemperature () const
	Get atmospheric (ground) temperature in deg celsius (for refraction).

void	setAtmospherePressure (double mbar)
	Set atmospheric (ground) pressure in mbar (for refraction).

double	getAtmospherePressure () const
	Get atmospheric (ground) pressure in mbar (for refraction).

const Extinction &	getExtinction () const
	Get the current valid extinction computation object.

const Refraction &	getRefraction () const
	Get the current valid refraction computation object.

float	getBig3dModelHaloRadius () const
	Get the radius of the big halo texture used when a 3d model is very bright.

void	setBig3dModelHaloRadius (float r)
	Set the radius of the big halo texture used when a 3d model is very bright.

Signals
void	relativeStarScaleChanged (double b)
	Emitted whenever the relative star scale changed.

void	absoluteStarScaleChanged (double b)
	Emitted whenever the absolute star scale changed.

void	twinkleAmountChanged (double b)
	Emitted whenever the twinkle amount changed.

void	flagTwinkleChanged (bool b)
	Emitted whenever the twinkle flag is toggled.

void	bortleScaleIndexChanged (int index)
	Emitted whenever the Bortle scale index changed.

void	flagDrawBigStarHaloChanged (bool b)
	Emitted when flag to draw big halo around stars changed.

void	flagStarMagnitudeLimitChanged (bool b)
	Emitted whenever the star magnitude limit flag is toggled.

void	flagNebulaMagnitudeLimitChanged (bool b)
	Emitted whenever the nebula magnitude limit flag is toggled.

void	flagPlanetMagnitudeLimitChanged (bool b)
	Emitted whenever the planet magnitude limit flag is toggled.

void	customStarMagLimitChanged (double limit)
	Emitted whenever the star magnitude limit changed.

void	customNebulaMagLimitChanged (double limit)
	Emitted whenever the nebula magnitude limit changed.

void	customPlanetMagLimitChanged (double limit)
	Emitted whenever the planet magnitude limit changed.

void	flagLuminanceAdaptationChanged (bool b)
	Emitted whenever the luminance adaptation flag is toggled.

void	daylightLabelThresholdChanged (double t)
	Emitted when threshold value to draw info text in black is changed.

void	extinctionCoefficientChanged (double coeff)

void	atmosphereTemperatureChanged (double celsius)

void	atmospherePressureChanged (double mbar)

Public Member Functions
	StelSkyDrawer (StelCore *core)
	Constructor.

	~StelSkyDrawer ()
	Destructor.

void	init ()
	Init parameters from config file.

void	update (double deltaTime)
	Update with respect to the time and StelProjector/StelToneReproducer state. More...

void	preDrawPointSource (StelPainter *p)
	Set the proper openGL state before making calls to drawPointSource. More...

void	postDrawPointSource (StelPainter *sPainter)
	Finalize the drawing of point sources.

bool	drawPointSource (StelPainter *sPainter, const Vec3f &v, const RCMag &rcMag, unsigned int bV, bool checkInScreen=false, float twinkleFactor=1.0f)
	Draw a point source halo. More...

bool	drawPointSource (StelPainter *sPainter, const Vec3f &v, const RCMag &rcMag, const Vec3f &bcolor, bool checkInScreen=false, float twinkleFactor=1.0f)

void	drawSunCorona (StelPainter *painter, const Vec3f &v, float radius, const Vec3f &color, const float alpha, const float angle)
	Draw an image of the solar corona onto the screen at position v. More...

void	postDrawSky3dModel (StelPainter *p, const Vec3f &v, float illuminatedArea, float mag, const Vec3f &color=Vec3f(1.f, 1.f, 1.f))
	Terminate drawing of a 3D model, draw the halo. More...

bool	computeRCMag (float mag, RCMag *) const
	Compute RMag and CMag from magnitude. More...

void	reportLuminanceInFov (float lum, bool fastAdaptation=false)
	Report that an object of luminance lum with an on-screen area of area pixels is currently displayed This information is used to determine the world adaptation luminance This method should be called during the update operations of the main loop. More...

void	preDraw ()
	To be called before the drawing stage starts.

Static Public Member Functions
static float	surfaceBrightnessToLuminance (float sb)
	Compute the luminance for an extended source with the given surface brightness. More...

static float	luminanceToSurfacebrightness (float lum)
	Compute the surface brightness from the luminance of an extended source. More...

static float	indexToBV (unsigned char bV)
	Convert quantized B-V index to float B-V.

static const Vec3f &	indexToColor (unsigned char bV)
	Convert quantized B-V index to RGB colors.

Properties
double	relativeStarScale
	Sets how much brighter stars will be bigger than fainter stars.

double	absoluteStarScale
	The absolute star brightness scale.

double	twinkleAmount

bool	flagStarTwinkle

int	bortleScaleIndex
	The current Bortle Scale index.

bool	flagDrawBigStarHalo

bool	flagStarMagnitudeLimit
	Controls the application of the user-defined star magnitude limit. More...

bool	flagNebulaMagnitudeLimit
	Controls the application of the user-defined nebula magnitude limit. More...

bool	flagPlanetMagnitudeLimit
	Controls the application of the user-defined planet magnitude limit. More...

double	customStarMagLimit
	User-defined magnitude limit for stars. More...

double	customNebulaMagLimit
	User-defined magnitude limit for deep-sky objects. More...

double	customPlanetMagLimit
	User-defined magnitude limit for solar system objects. More...

bool	flagLuminanceAdaptation
	Simulate the eye's luminance adaptation?

double	daylightLabelThreshold
	a customizable value in cd/m^2 which is used to decide when to render the InfoText in black (when sky is brighter than this)

double	extinctionCoefficient

double	atmosphereTemperature

double	atmospherePressure

Member Function Documentation

◆ computeRCMag()

bool StelSkyDrawer::computeRCMag	(	float	mag,
		RCMag *
	)		const

Parameters

mag	the object integrated V magnitude
rcMag	array of 2 floats containing the radius and luminance

Returns: false if the object is too faint to be displayed

◆ drawPointSource()

bool StelSkyDrawer::drawPointSource	(	StelPainter *	sPainter,
		const Vec3f &	v,
		const RCMag &	rcMag,
		unsigned int	bV,
		bool	checkInScreen = `false`,
		float	twinkleFactor = `1.0f`
	)

inline

Parameters

sPainter	the StelPainter to use for drawing.
v	the 3d position of the source in J2000 reference frame
rcMag	the radius and luminance of the source as computed by computeRCMag()
bV	the source B-V index
checkInScreen	whether source in screen should be checked to avoid unnecessary drawing.
twinkleFactor	allows height-dependent twinkling. Recommended value: min(1,1-0.9*sin(altitude)). Allowed values [0..1]

Returns: true if the source was actually visible and drawn

◆ drawSunCorona()

void StelSkyDrawer::drawSunCorona	(	StelPainter *	painter,
		const Vec3f &	v,
		float	radius,
		const Vec3f &	color,
		const float	alpha,
		const float	angle
	)

Parameters

radius	depends on the actually used texture and current disk size of the sun.
alpha	opacity value. Set 1 for full visibility, but usually keep close to 0 except during solar eclipses.
angle	includes parallactic angle (if alt/azimuth frame) and angle between solar polar axis and celestial equator.

◆ getBortleScaleIndex

int StelSkyDrawer::getBortleScaleIndex ( ) const

inlineslot

See also: https://en.wikipedia.org/wiki/Bortle_scale

◆ getFlagForcedTwinkle

bool StelSkyDrawer::getFlagForcedTwinkle ( ) const

inlineslot

Note: option for planetariums

◆ getFlagNebulaMagnitudeLimit

bool StelSkyDrawer::getFlagNebulaMagnitudeLimit ( ) const

inlineslot

Returns: true if the user-defined nebula magnitude limit is in force.

◆ getFlagPlanetMagnitudeLimit

bool StelSkyDrawer::getFlagPlanetMagnitudeLimit ( ) const

inlineslot

Returns: true if the user-defined nebula magnitude limit is in force.

◆ getFlagStarMagnitudeLimit

bool StelSkyDrawer::getFlagStarMagnitudeLimit ( ) const

inlineslot

Returns: true if the user-defined star magnitude limit is in force.

◆ getLimitLuminance

float StelSkyDrawer::getLimitLuminance ( ) const

inlineslot

RGB<0.05) It depends on the zoom level, on the eye adapation and on the point source rendering parameters

Returns: the limit V luminance at which an object will be visible

◆ getLimitMagnitude

float StelSkyDrawer::getLimitMagnitude ( ) const

inlineslot

Returns: the limit V mag at which a point source will be displayed

◆ getNELMFromBortleScale

static float StelSkyDrawer::getNELMFromBortleScale ( int idx )

staticslot

idx Bortle Scale Index (valid: 1..9, will be forced to valid range)

◆ luminanceToSurfacebrightness()

static float StelSkyDrawer::luminanceToSurfacebrightness ( float lum )

static

Parameters

lum	luminance in cd/m^2

Returns: surface brightness in V magnitude/arcmin^2

◆ postDrawSky3dModel()

void StelSkyDrawer::postDrawSky3dModel	(	StelPainter *	p,
		const Vec3f &	v,
		float	illuminatedArea,
		float	mag,
		const Vec3f &	color = `Vec3f(1.f, 1.f, 1.f)`
	)

Parameters

p	the StelPainter instance to use for this drawing operation
v	the 3d position of the source in J2000 reference frame
illuminatedArea	the illuminated area in arcmin^2
mag	the source integrated magnitude
color	the object halo RGB color

◆ preDrawPointSource()

void StelSkyDrawer::preDrawPointSource ( StelPainter * p )

Parameters

p	a pointer to a valid instance of a Painter. The instance must be valid until postDrawPointSource() is called

◆ reportLuminanceInFov()

void StelSkyDrawer::reportLuminanceInFov	(	float	lum,
		bool	fastAdaptation = `false`
	)

Parameters

lum	luminance in cd/m^2
fastAdaptation	adapt the eye quickly if true, other wise use a smooth adaptation

◆ setBortleScaleIndex

void StelSkyDrawer::setBortleScaleIndex ( int index )

slot

See also: https://en.wikipedia.org/wiki/Bortle_scale

◆ setCustomNebulaMagnitudeLimit

void StelSkyDrawer::setCustomNebulaMagnitudeLimit ( double limit )

inlineslot

In force only if flagNebulaMagnitudeLimit is set.

◆ setCustomPlanetMagnitudeLimit

void StelSkyDrawer::setCustomPlanetMagnitudeLimit ( double limit )

inlineslot

In force only if flagPlanetMagnitudeLimit is set.

◆ setCustomStarMagnitudeLimit

void StelSkyDrawer::setCustomStarMagnitudeLimit ( double limit )

inlineslot

In force only if flagStarMagnitudeLimit is set.

◆ setFlagForcedTwinkle

void StelSkyDrawer::setFlagForcedTwinkle ( bool b )

inlineslot

Note: option for planetariums

◆ setFlagHasAtmosphere

void StelSkyDrawer::setFlagHasAtmosphere ( bool b )

inlineslot

This is used to avoid twinkling/simulate extinction/refraction.

◆ setFlagNebulaMagnitudeLimit

void StelSkyDrawer::setFlagNebulaMagnitudeLimit ( bool b )

inlineslot

If enabled, deep-sky objects fainter than the magnitude set with setCustomNebulaMagnitudeLimit() will not be displayed.

◆ setFlagPlanetMagnitudeLimit

void StelSkyDrawer::setFlagPlanetMagnitudeLimit ( bool b )

inlineslot

If enabled, planets, planetary moons, asteroids (KBO, ...) and comets fainter than the magnitude set with setCustomPlanetMagnitudeLimit() will not be displayed.

◆ setFlagStarMagnitudeLimit

void StelSkyDrawer::setFlagStarMagnitudeLimit ( bool b )

inlineslot

If enabled, stars fainter than the magnitude set with setCustomStarMagnitudeLimit() will not be displayed.

◆ surfaceBrightnessToLuminance()

static float StelSkyDrawer::surfaceBrightnessToLuminance ( float sb )

static

Parameters

sb	surface brightness in V magnitude/arcmin^2

Returns: the luminance in cd/m^2

◆ update()

void StelSkyDrawer::update ( double deltaTime )

Parameters

deltaTime the time increment in second since last call.

Property Documentation

◆ customNebulaMagLimit

double StelSkyDrawer::customNebulaMagLimit

readwrite

Interpreted as a lower limit - nebulae fainter than this value will not be displayed. Used if flagNebulaMagnitudeLimit is true.

◆ customPlanetMagLimit

double StelSkyDrawer::customPlanetMagLimit

readwrite

Interpreted as a lower limit - planets fainter than this value will not be displayed. Used if flagPlanetMagnitudeLimit is true.

◆ customStarMagLimit

double StelSkyDrawer::customStarMagLimit

readwrite

Interpreted as a lower limit - stars fainter than this value will not be displayed. Used if flagStarMagnitudeLimit is true.

◆ flagNebulaMagnitudeLimit

bool StelSkyDrawer::flagNebulaMagnitudeLimit

readwrite

See also: customNebulaMagnitudeLimit

◆ flagPlanetMagnitudeLimit

bool StelSkyDrawer::flagPlanetMagnitudeLimit

readwrite

See also: customPlanetMagnitudeLimit

◆ flagStarMagnitudeLimit

bool StelSkyDrawer::flagStarMagnitudeLimit

readwrite

See also: customStarMagnitudeLimit

Public Slots

Signals

Public Member Functions

Static Public Member Functions

Properties

Member Function Documentation

◆ computeRCMag()

◆ drawPointSource()

◆ drawSunCorona()

◆ getBortleScaleIndex

◆ getFlagForcedTwinkle

◆ getFlagNebulaMagnitudeLimit

◆ getFlagPlanetMagnitudeLimit

◆ getFlagStarMagnitudeLimit

◆ getLimitLuminance

◆ getLimitMagnitude

◆ getNELMFromBortleScale

◆ luminanceToSurfacebrightness()

◆ postDrawSky3dModel()

◆ preDrawPointSource()

◆ reportLuminanceInFov()

◆ setBortleScaleIndex

◆ setCustomNebulaMagnitudeLimit

◆ setCustomPlanetMagnitudeLimit

◆ setCustomStarMagnitudeLimit

◆ setFlagForcedTwinkle

◆ setFlagHasAtmosphere

◆ setFlagNebulaMagnitudeLimit

◆ setFlagPlanetMagnitudeLimit

◆ setFlagStarMagnitudeLimit

◆ surfaceBrightnessToLuminance()

◆ update()

Property Documentation

◆ customNebulaMagLimit

◆ customPlanetMagLimit

◆ customStarMagLimit

◆ flagNebulaMagnitudeLimit

◆ flagPlanetMagnitudeLimit

◆ flagStarMagnitudeLimit