Defines a 2D-Background for the OpenGL framebuffer background. More...

#include <SLBackground.h>

Inheritance diagram for SLBackground:

Public Member Functions
	SLBackground (SLstring shaderDir)
	The constructor initializes to a uniform BLACK background color. More...

	SLBackground (SLGLProgram textureOnlyProgram, SLGLProgram colorAttributeProgram)
	The constructor initializes to a uniform gray background color. More...

	~SLBackground ()

void	render (SLint widthPX, SLint heightPX)
	Draws the background as 2D rectangle with OpenGL buffers. More...

void	renderInScene (const SLMat4f &wm, const SLVec3f &LT, const SLVec3f &LB, const SLVec3f &RT, const SLVec3f &RB)
	Draws the background as a quad on the far clipping plane. More...

SLCol4f	colorAtPos (SLfloat x, SLfloat y, SLfloat width, SLfloat height)
	Returns the interpolated color at the pixel position p[x,y] used in raytracing. More...

void	rebuild ()

void	colors (const SLCol4f &uniformColor)
	Sets a uniform background color. More...

void	colors (const SLCol4f &topColor, const SLCol4f &bottomColor)
	Sets a gradient top-down background color. More...

void	colors (const SLCol4f &topLeftColor, const SLCol4f &bottomLeftColor, const SLCol4f &topRightColor, const SLCol4f &bottomRightColor)
	Sets a gradient background color with a color per corner. More...

void	texture (SLGLTexture *backgroundTexture, bool fixAspectRatio=false)
	If flag _repeatBlurred is true the texture is not distorted if its size does not fit to screen aspect ratio. Instead it is repeated. More...

SLVCol4f	colors ()

SLCol4f	avgColor ()

SLbool	isUniform () const

SLGLTexture *	texture ()

const SLRectf &	rect () const

Public Member Functions inherited from SLObject
	SLObject (const SLstring &Name="", const SLstring &url="")

virtual	~SLObject ()

void	name (const SLstring &Name)

void	url (const SLstring &url)

const SLstring &	name () const

const SLstring &	url () const

Private Attributes
SLbool	_isUniform
	Flag if background has uniform color. More...

SLVCol4f	_colors
	Vector of 4 corner colors {TL,BL,TR,BR}. More...

SLCol4f	_avgColor
	Average color of all 4 corner colors. More...

SLGLTexture *	_texture
	Pointer to a background texture. More...

SLGLTexture *	_textureError
	Pointer to a error texture if background texture is not available. More...

SLint	_resX
	Background resolution in x-dir. More...

SLint	_resY
	Background resolution in y-dir. More...

SLRectf	_rect
	Background rect (it may be different to viewport size) More...

SLGLVertexArray	_vao
	OpenGL Vertex Array Object for drawing. More...

SLGLProgram *	_textureOnlyProgram = nullptr

SLGLProgram *	_colorAttributeProgram = nullptr

bool	_deletePrograms = false

bool	_fixAspectRatio = false
	if true, the background is centered and stretched to the screen boarders while keeping the textures aspect ratio More...

Additional Inherited Members
Protected Attributes inherited from SLObject
SLstring	_name
	name of an object More...

SLstring	_url
	uniform resource locator More...

Detailed Description

Defines a 2D-Background for the OpenGL framebuffer background.

The background can either be defined with a texture or with 4 colors for the corners of the frame buffer. For a uniform background color the color at index 0 of the _colors vector is taken. Every instance of SLCamera has a background that is displayed on the far clipping plane if the camera is not the active one. The OpenGL rendering is done in SLSceneView::draw3DGL for the active camera or in SLCamera::drawMeshes for inactive ones.

Constructor & Destructor Documentation

◆ SLBackground() [1/2]

SLBackground::SLBackground ( SLstring shaderDir )

The constructor initializes to a uniform BLACK background color.

◆ SLBackground() [2/2]

SLBackground::SLBackground	(	SLGLProgram *	textureOnlyProgram,
		SLGLProgram *	colorAttributeProgram
	)

The constructor initializes to a uniform gray background color.

◆ ~SLBackground()

SLBackground::~SLBackground ( )

Member Function Documentation

◆ avgColor()

SLCol4f SLBackground::avgColor ( )

inline

◆ colorAtPos()

SLCol4f SLBackground::colorAtPos	(	SLfloat	x,
		SLfloat	y,
		SLfloat	width,
		SLfloat	height
	)

Returns the interpolated color at the pixel position p[x,y] used in raytracing.

Returns the interpolated color at the pixel position p[x,y] for ray tracing. x is expected to be between 0 and width of the RT-frame. y is expected to be between 0 and height of the RT-frame. width is the width of the RT-frame height is the height of the RT-frame

C w B +--—+ | p /| | * / | h | / | | / | |/ | 0 +--—+ A 0

◆ colors() [1/4]

SLVCol4f SLBackground::colors ( )

inline

◆ colors() [2/4]

void SLBackground::colors	(	const SLCol4f &	topColor,
		const SLCol4f &	bottomColor
	)

Sets a gradient top-down background color.

◆ colors() [3/4]

void SLBackground::colors	(	const SLCol4f &	topLeftColor,
		const SLCol4f &	bottomLeftColor,
		const SLCol4f &	topRightColor,
		const SLCol4f &	bottomRightColor
	)

Sets a gradient background color with a color per corner.

◆ colors() [4/4]

void SLBackground::colors ( const SLCol4f & uniformColor )

Sets a uniform background color.

◆ isUniform()

SLbool SLBackground::isUniform ( ) const

inline

◆ rebuild()

void SLBackground::rebuild ( )

inline

◆ rect()

const SLRectf & SLBackground::rect ( ) const

inline

◆ render()

void SLBackground::render	(	SLint	widthPX,
		SLint	heightPX
	)

Draws the background as 2D rectangle with OpenGL buffers.

Draws the background as a flat 2D rectangle with a height and a width on two triangles with zero in the bottom left corner:
w +--—+ | /| | / | h | / | | / | |/ | 0 +--—+ 0

We render the quad as a triangle strip:
0 2 +--—+ | /| | / | | / | | / | |/ | +--—+ 1 3

◆ renderInScene()

void SLBackground::renderInScene	(	const SLMat4f &	wm,
		const SLVec3f &	LT,
		const SLVec3f &	LB,
		const SLVec3f &	RT,
		const SLVec3f &	RB
	)

Draws the background as a quad on the far clipping plane.

We render the quad as a triangle strip:
LT RT +--—+ | /| | / | | / | | / | |/ | +--—+ LB RB

◆ texture() [1/2]

SLGLTexture * SLBackground::texture ( )

inline

◆ texture() [2/2]

void SLBackground::texture	(	SLGLTexture *	backgroundTexture,
		bool	fixAspectRatio = `false`
	)

If flag _repeatBlurred is true the texture is not distorted if its size does not fit to screen aspect ratio. Instead it is repeated.

Sets the background texture.

Member Data Documentation

◆ _avgColor

SLCol4f SLBackground::_avgColor

private

Average color of all 4 corner colors.

◆ _colorAttributeProgram

SLGLProgram* SLBackground::_colorAttributeProgram = nullptr

private

◆ _colors

SLVCol4f SLBackground::_colors

private

Vector of 4 corner colors {TL,BL,TR,BR}.

◆ _deletePrograms

bool SLBackground::_deletePrograms = false

private

◆ _fixAspectRatio

bool SLBackground::_fixAspectRatio = false

private

if true, the background is centered and stretched to the screen boarders while keeping the textures aspect ratio

◆ _isUniform

SLbool SLBackground::_isUniform

private

Flag if background has uniform color.

◆ _rect

SLRectf SLBackground::_rect

private

Background rect (it may be different to viewport size)

◆ _resX

SLint SLBackground::_resX

private

Background resolution in x-dir.

◆ _resY

SLint SLBackground::_resY

private

Background resolution in y-dir.

◆ _texture

SLGLTexture* SLBackground::_texture

private

Pointer to a background texture.

◆ _textureError

SLGLTexture* SLBackground::_textureError

private

Pointer to a error texture if background texture is not available.

◆ _textureOnlyProgram

SLGLProgram* SLBackground::_textureOnlyProgram = nullptr

private

◆ _vao

SLGLVertexArray SLBackground::_vao

private

OpenGL Vertex Array Object for drawing.

The documentation for this class was generated from the following files:

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SLBackground() [1/2]

◆ SLBackground() [2/2]

◆ ~SLBackground()

Member Function Documentation

◆ avgColor()

◆ colorAtPos()

◆ colors() [1/4]

◆ colors() [2/4]

◆ colors() [3/4]

◆ colors() [4/4]

◆ isUniform()

◆ rebuild()

◆ rect()

◆ render()

◆ renderInScene()

◆ texture() [1/2]

◆ texture() [2/2]

Member Data Documentation

◆ _avgColor

◆ _colorAttributeProgram

◆ _colors

◆ _deletePrograms

◆ _fixAspectRatio

◆ _isUniform

◆ _rect

◆ _resX

◆ _resY

◆ _texture

◆ _textureError

◆ _textureOnlyProgram

◆ _vao