candle::LightSource Class Reference

Interface for objects that emit light. More...

#include <LightSource.hpp>

Inheritance diagram for candle::LightSource:

Public Member Functions
	LightSource ()
	Constructor.
void	setIntensity (float intensity)
	Set the light intensity. More...
float	getIntensity () const
	Get the intensity of the light. More...
void	setColor (const sf::Color &color)
	Set the light color. More...
sf::Color	getColor () const
	Get the plain color of the light. More...
virtual void	setFade (bool fade)
	Set the value of the fade flag. More...
virtual bool	getFade () const
	Check if the light fades or not. More...
void	setRange (float range)
	Set the range of the illuminated area. More...
float	getRange () const
	Get the range of the illuminated area. More...
virtual void	castLight (const EdgeVector::iterator &begin, const EdgeVector::iterator &end)=0
	Modify the polygon of the illuminated area with a raycasting algorithm. More...

Private Member Functions
virtual void	draw (sf::RenderTarget &t, sf::RenderStates st) const =0
	Draw the object to a target.

Detailed Description

Interface for objects that emit light.

LightSources use raycasting algorithms to compute the polygon illuminated by the light. The main difference between the implementations, RadialLight and DirectedLight, is whether the constant is the origin or the direction of the rays.

LightSources manage their colour separating the alpha value from the RGB . This is convenient to manipulate color of the light (interpreted as the RGB value) and intensity (interpreted as the alpha value) separately.

By default, they use a sf::BlendAdd mode. This means that you can specify any other blend mode you want, except sf::BlendAlpha, that will be changed to the additive mode.

Member Function Documentation

setIntensity()

void candle::LightSource::setIntensity

(

float

intensity

)

Set the light intensity.

The intensity of the light determines two things: how much fog opacity it reduces when drawn in a LightingArea * in FOG mode, and how much presence its color has when drawn normally.

The default value is 1.

Parameters

intensity

Value from 0 to 1. At 0 the light is invisible.

See also

getIntensity

getIntensity()

float candle::LightSource::getIntensity

(

)

const

Get the intensity of the light.

Returns

The light intensity.

See also

setIntensity

setColor()

void candle::LightSource::setColor

(

const sf::Color &

color

)

Set the light color.

The light color refers only to the RGB values.

The default value is sf::Color::White

Parameters

color

New color of the light. The alpha value is ignored.

See also

getColor

getColor()

sf::Color candle::LightSource::getColor

(

)

const

Get the plain color of the light.

The light color refers only to the RGB values.

Returns

The light color.

See also

setColor

setFade()

virtual void candle::LightSource::setFade ( bool  fade )

virtual

Set the value of the fade flag.

when the fade flag is set, the light will lose intensity in the limits of its range. Otherwise, the intensity will remain constant.

The default value is true.

Parameters

fade	Value to set the flag.

See also

getFade

getFade()

virtual bool candle::LightSource::getFade ( ) const

virtual

Check if the light fades or not.

Returns

The value of the fade flag.

See also

setFade

setRange()

void candle::LightSource::setRange

(

float

range

)

Set the range of the illuminated area.

The range of the light indicates the how far a light ray may hit from its origin.

Parameters

range

Range of the illuminated area.

See also

getRange, setFade

getRange()

float candle::LightSource::getRange

(

)

const

Get the range of the illuminated area.

Returns

The range of the illuminated area.

See also

setRange

castLight()

virtual void candle::LightSource::castLight ( const EdgeVector::iterator &  begin, const EdgeVector::iterator &  end  )

pure virtual

Modify the polygon of the illuminated area with a raycasting algorithm.

The algorithm needs to know which edges to use to cast shadows. They are specified within a range of two iterators of a vector of edges of type sfu::Line.

Parameters

begin	Iterator to the first sfu::Line of the vector to take into account.
end	Iterator to the first sfu::Line of the vector not to be taken into account.

See also

setRange, EdgeVector

Implemented in candle::DirectedLight, and candle::RadialLight.