Light Class Reference

Base class for all light types supported in a Scene.

#include <Rendering/SceneComponents/Lights/light.h>

Inheritance diagram for Light:

Public Member Functions
	Light (const QString &id="")
	~Light () override
Light *	clone () const override=0
const QColor &	getColor () const
double	getIntensity () const
Mesh::Vector3d	getOrientation () const
Mesh::Vector3d	getPosition () const
void	setColor (const QColor &color)
void	setIntensity (double d)
virtual bool	visit (LightsProcessor &processor)=0
bool	visit (SceneProcessor &processor) override
Public Member Functions inherited from SceneItem
	~SceneItem () override
SceneItem *	clone () const override=0
bool	getEnabled () const
const QString &	getId () const
const Mesh::BoundingBoxMinimal &	getLocalBoundingBox () const
virtual Mesh::TransformMatrix	getMatrixGlobal () const
virtual Mesh::TransformMatrix	getMatrixLocal () const
const QString &	getName () const
Mesh::TransformMatrix	getParentMatrixGlobal () const
Transform *	getParentTransform ()
void	setEnabled (bool b)
void	setId (const QString &itemId)
virtual void	setLocalBoundingBox (const Mesh::BoundingBoxMinimal &bb)
void	setName (const QString &name)
virtual Transform *	toTransform ()
virtual const Transform *	toTransform () const
virtual void	updateGlobalMatrix ()
virtual bool	visit (SceneProcessor &processor)=0
Public Member Functions inherited from Observable
virtual	~Observable ()
void	attachObserver (Observer &observer)
void	destroy ()
void	detachObserver (Observer &observer)
void	notifyEvent (const ObservableEvent &event)
Public Member Functions inherited from Clonable
virtual	~Clonable ()=default
virtual Clonable *	clone () const =0

Protected Member Functions
	Light (const Light &light)
Light &	operator= (const Light &light)
Protected Member Functions inherited from SceneItem
	SceneItem (const QString &id)
	SceneItem (const SceneItem &item)
virtual void	addToScene (Scene &scene, const QString &opIdPath="")
bool	isTransformModified () const
SceneItem &	operator= (const SceneItem &item)
void	setTransformModified (bool b)
Protected Member Functions inherited from Observable
	Observable ()
	Observable (const Observable &)

Constructor & Destructor Documentation

Light() [1/2]

Light ( const Light &  light )

protected

Light() [2/2]

Light

(

const QString &

id = ""

)

Creates a light with full intensity (ie intensity == 1) and with a white color. The light will be enabled by default.

~Light()

~Light ( )

override

Member Function Documentation

clone()

Light * clone ( ) const

overridepure virtual

Returns

A clone of this item.

Subclasses must reimplement this function to return a clone of themselves.

Implements SceneItem.

Implemented in AmbientLight, DirectionalLight, PointLight, and SpotLight.

getColor()

const QColor & getColor

(

)

const

Returns

The color of the light.

See also

setColor()

getIntensity()

double getIntensity

(

)

const

Returns

The intensity of the light.

See also

setIntensity()

getOrientation()

Vector3d getOrientation

(

)

const

Returns

The light's orientation in global co-ordinates of the scene it is part of. If it is not part of a scene, then the orientation will be looking down the negative Z axis direction.

A light with no transformation points in the direction of the negative Z axis. This is the same convention as used by cameras and it also matches the default direction of spot lights for OpenGL.

Note

Not all lights make use of the orientation, since some are only positional with no directionality (eg ambient and point lights).

See also

getPosition()

getPosition()

Vector3d getPosition

(

)

const

Returns

The light's position in global co-ordinates of the scene it is part of. If it is not part of a scene, then the position will be the origin because the light will have no parent transform.

This is just the translation component of the parent global matrix. It is defined in the same way as for Camera objects except a Camera also has its own local transform, whereas a Light does not.

See also

getOrientation()

operator=()

Light & operator= ( const Light &  light )

protected

setColor()

void setColor

(

const QColor &

color

)

Parameters

color

The new color for the light.

The light's color controls what color content the light casts into the scene. You can think of the color as being similar to applying a color filter in front of a white light. The color is multiplied by the light's intensity when used in a scene.

See also

getColor()

setIntensity()

void setIntensity

(

double

d

)

Parameters

d	The new intensity for the light.

The intensity of the light acts like a multiplier on the light's color (only its red, green and blue components, not the alpha component). It allows the light intensity to be easily adjusted without affecting the color balance. Setting the intensity to zero does not disable the light, it only has the effect of turning the light off but it is still processed by LightsProcessor subclasses. For some rendering engines with support for only a limited number of lights, this is important because only the enabled/disabled state determines whether or not the processor can skip the light.

It should also be noted that some rendering engines might allow negative intensities to give the artificial effect of subtracting light from a surface. Not all renderers will support this behavior though, in which case they must treat the negative intensities the same as a zero intensity.

See also

getIntensity(), setEnabled()

visit() [1/2]

virtual bool visit ( LightsProcessor &  processor )

pure virtual

Parameters

processor

The light processor visiting this light.

Light subclasses should reimplement this function to call processor.visit() and return the result of that call. This is the usual visitor pattern as used for other scene items and model processors.

Implemented in AmbientLight, DirectionalLight, PointLight, and SpotLight.

visit() [2/2]

bool visit ( SceneProcessor &  processor )

overridevirtual

Implements SceneItem.