Singleton class holding all OpenGL states. More...

#include <SLGLState.h>

Public Member Functions
void	onInitialize (const SLCol4f &clearColor)
	On init GL. More...

void	initAll ()

bool	hasMultiSampling () const

void	unbindAnythingAndFlush ()
	finishes all GL commands More...

SLbool	pixelFormatIsSupported (SLint pixelFormat)
	Returns true if the according GL pixel format is valid in the GL context. More...

void	readPixels (void *buffer)
	Reads the front framebuffer pixels into the passed buffer. More...

void	depthTest (SLbool state)

void	depthMask (SLbool state)

void	depthFunc (SLenum func)

void	cullFace (SLbool state)

void	blend (SLbool state)

void	blendFunc (SLenum blendFuncSFactor, SLenum blendFuncDFactor)
	Sets new blend function source and destination factors. More...

void	multiSample (SLbool state)

void	polygonLine (SLbool state)

void	polygonOffsetPoint (SLbool enabled, SLfloat factor=-1.0f, SLfloat units=-1.0f)

void	polygonOffsetLine (SLbool enabled, SLfloat factor=-1.0f, SLfloat units=-1.0f)

void	polygonOffsetFill (SLbool enabled, SLfloat factor=-1.0f, SLfloat units=-1.0f)

void	viewport (SLint x, SLint y, SLsizei width, SLsizei height)

void	colorMask (GLboolean r, GLboolean g, GLboolean b, GLboolean a)

void	useProgram (SLuint progID)

void	bindTexture (SLenum target, SLuint textureID)

void	activeTexture (SLenum textureUnit)

void	clearColor (const SLCol4f &c)

void	currentMaterial (SLMaterial *mat)

void	clearColorBuffer ()

void	clearDepthBuffer ()

void	clearColorDepthBuffer ()

SLbool	blend () const

SLstring	glVersion ()

SLstring	glVersionNO ()

SLfloat	glVersionNOf () const

SLstring	glVendor ()

SLstring	glRenderer ()

SLstring	glSLVersion ()

SLstring	glSLVersionNO ()

SLbool	glIsES () const

SLbool	glIsES2 () const

SLbool	glIsES3 () const

SLint	glMaxTexUnits () const

SLint	glMaxTexSize () const

SLbool	glHasGeometryShaders () const

SLbool	hasExtension (const SLstring &e)

SLVec4i	viewport ()

SLMat4f	viewportMatrix ()

SLMaterial *	currentMaterial ()

SLstring	getGLVersionNO ()
	Returns the OpenGL version number as a string. More...

SLstring	getSLVersionNO ()
	Returns the OpenGL Shading Language version number as a string. More...

Static Public Member Functions
static SLGLState *	instance ()
	Public static instance getter for singleton pattern. More...

static void	deleteInstance ()
	global destruction More...

static void	getGLError (const char *file, int line, bool quit)
	Checks if an OpenGL error occurred. More...

Public Attributes
SLMat4f	modelMatrix
	Init all states. More...

SLMat4f	projectionMatrix
	matrix for projection transform More...

SLMat4f	viewMatrix
	matrix for the active cameras view transform More...

SLMat4f	textureMatrix
	matrix for the texture transform More...

Private Member Functions
	SLGLState ()
	private onetime constructor More...

	~SLGLState ()
	destruction in ~SLScene More...

Private Attributes
SLbool	_isInitialized
	flag for first init More...

SLstring	_glVersion
	OpenGL Version string. More...

SLstring	_glVersionNO
	OpenGL Version number string. More...

SLfloat	_glVersionNOf
	OpenGL Version number as float. More...

SLstring	_glVendor
	OpenGL Vendor string. More...

SLstring	_glRenderer
	OpenGL Renderer string. More...

SLstring	_glSLVersion
	GLSL Version string. More...

SLstring	_glSLVersionNO
	GLSL Version number string. More...

SLstring	_glExtensions
	OpenGL extensions string. More...

SLbool	_glIsES2
	Flag if OpenGL ES2. More...

SLbool	_glIsES3
	Flag if OpenGL ES3. More...

SLint	_glMaxTexUnits
	glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &_glMaxTexUnits); More...

SLint	_glMaxTexSize
	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &_glMaxTexSize); More...

SLbool	_blend
	blending default false; More...

SLenum	_blendFuncSfactor
	blend function source factor enum More...

SLenum	_blendFuncDfactor
	blend function destination factor enum More...

SLbool	_depthTest
	GL_DEPTH_TEST state. More...

SLbool	_depthMask
	glDepthMask state More...

SLenum	_depthFunc
	depth buffer comparison function More...

SLbool	_cullFace
	Face culling state. More...

SLbool	_multisample
	Multisampling state. More...

SLint	_multiSampleSamples
	NO. of multisampling samples. More...

SLbool	_polygonLine
	Line polygon state. More...

SLbool	_polygonOffsetPointEnabled
	GL_POLYGON_OFFSET_POINT state enabled. More...

SLbool	_polygonOffsetLineEnabled
	GL_POLYGON_OFFSET_LINE state enabled. More...

SLbool	_polygonOffsetFillEnabled
	GL_POLYGON_OFFSET_FILL state enabled. More...

SLVec4i	_viewport
	viewport size (x,y,w,h) of the framebuffer More...

SLCol4f	_clearColor
	clear color More...

SLuint	_programID
	current shader program id More...

SLenum	_textureUnit
	current texture unit More...

SLenum	_textureTarget
	current texture target More...

SLuint	_textureID
	current texture id More...

GLboolean	_colorMaskR
	current color mask for R More...

GLboolean	_colorMaskG
	current color mask for G More...

GLboolean	_colorMaskB
	current color mask for B More...

GLboolean	_colorMaskA
	current color mask for A More...

SLVstring	errors
	vector for errors collected in getGLError More...

SLMaterial *	_currentMaterial

Static Private Attributes
static SLGLState *	_instance = nullptr
	global singleton object More...

Detailed Description

Singleton class holding all OpenGL states.

The main purpose of the SLGLState class is to replace all the OpenGL states and functionality that has been removed from the core profile of OpenGL. The core profile started from OpenGL version 3.0 has e.g. no more internal matrices, lighting or material states. It also has no more fixed function pipeline on the GPU witch means, that core profile OpenGL only works with custom shader programs written in OpenGL Shading Language (GLSL). The second purpose is to concentrate OpenGL functionality and to reduce redundant state changes.

Constructor & Destructor Documentation

◆ SLGLState()

SLGLState::SLGLState ( )

private

private onetime constructor

Private constructor should be called only once for a singleton class.

◆ ~SLGLState()

SLGLState::~SLGLState ( )

private

destruction in ~SLScene

The destructor only empties the stacks

Member Function Documentation

◆ activeTexture()

void SLGLState::activeTexture ( SLenum textureUnit )

SLGLState::activeTexture sets the current active texture unit

◆ bindTexture()

void SLGLState::bindTexture	(	SLenum	target,
		SLuint	textureID
	)

SLGLState::bindTexture sets the current active texture.

◆ blend() [1/2]

SLbool SLGLState::blend ( ) const

inline

◆ blend() [2/2]

void SLGLState::blend ( SLbool stateNew )

SLGLState::blend enables or disables alpha blending but only if the state really changes.

◆ blendFunc()

void SLGLState::blendFunc	(	SLenum	blendFuncSFactor,
		SLenum	blendFuncDFactor
	)

Sets new blend function source and destination factors.

◆ clearColor()

void SLGLState::clearColor ( const SLCol4f & c )

◆ clearColorBuffer()

void SLGLState::clearColorBuffer ( )

inline

◆ clearColorDepthBuffer()

void SLGLState::clearColorDepthBuffer ( )

inline

◆ clearDepthBuffer()

void SLGLState::clearDepthBuffer ( )

inline

◆ colorMask()

void SLGLState::colorMask	(	GLboolean	r,
		GLboolean	g,
		GLboolean	b,
		GLboolean	a
	)

SLGLState::colorMask sets the OpenGL colorMask for framebuffer masking

◆ cullFace()

void SLGLState::cullFace ( SLbool stateNew )

SLGLState::cullFace sets the GL_CULL_FACE state but only if the state really changes. If face culling is turned on no back faces are processed.

◆ currentMaterial() [1/2]

SLMaterial * SLGLState::currentMaterial ( )

inline

◆ currentMaterial() [2/2]

void SLGLState::currentMaterial ( SLMaterial * mat )

inline

◆ deleteInstance()

void SLGLState::deleteInstance ( )

static

global destruction

Public static destruction.

◆ depthFunc()

void SLGLState::depthFunc ( SLenum func )

SLGLState::depthFunc specifies the depth comparison function. Symbolic constants GL_NEVER, GL_LESS, GL_EQUAL, GL_LEQUAL, GL_GREATER, GL_NOTEQUAL, GL_GEQUAL, and GL_ALWAYS are accepted. The initial value is GL_LESS.

◆ depthMask()

void SLGLState::depthMask ( SLbool stateNew )

SLGLState::depthTest enables or disables depth buffer writing but only if the state really changes. Turning on depth masking freezes the depth test but keeps all values in the depth buffer.

◆ depthTest()

void SLGLState::depthTest ( SLbool stateNew )

SLGLState::depthTest enables or disables depth testing but only if the state really changes. The depth test decides for each pixel in the depth buffer which polygon is the closest to the eye.

◆ getGLError()

void SLGLState::getGLError	(	const char *	file,
		int	line,
		bool	quit
	)

static

Checks if an OpenGL error occurred.

◆ getGLVersionNO()

SLstring SLGLState::getGLVersionNO ( )

Returns the OpenGL version number as a string.

The string returned by glGetString can contain additional vendor information such as the build number and the brand name. For the OpenGL version string "4.5.0 NVIDIA 347.68" the function returns "4.5"

◆ getSLVersionNO()

SLstring SLGLState::getSLVersionNO ( )

Returns the OpenGL Shading Language version number as a string.

The string returned by glGetString can contain additional vendor information such as the build number and the brand name. For the shading language string "Nvidia GLSL 4.5" the function returns "450"

◆ glHasGeometryShaders()

SLbool SLGLState::glHasGeometryShaders ( ) const

inline

◆ glIsES()

SLbool SLGLState::glIsES ( ) const

inline

◆ glIsES2()

SLbool SLGLState::glIsES2 ( ) const

inline

◆ glIsES3()

SLbool SLGLState::glIsES3 ( ) const

inline

◆ glMaxTexSize()

SLint SLGLState::glMaxTexSize ( ) const

inline

◆ glMaxTexUnits()

SLint SLGLState::glMaxTexUnits ( ) const

inline

◆ glRenderer()

SLstring SLGLState::glRenderer ( )

inline

◆ glSLVersion()

SLstring SLGLState::glSLVersion ( )

inline

◆ glSLVersionNO()

SLstring SLGLState::glSLVersionNO ( )

inline

◆ glVendor()

SLstring SLGLState::glVendor ( )

inline

◆ glVersion()

SLstring SLGLState::glVersion ( )

inline

◆ glVersionNO()

SLstring SLGLState::glVersionNO ( )

inline

◆ glVersionNOf()

SLfloat SLGLState::glVersionNOf ( ) const

inline

◆ hasExtension()

SLbool SLGLState::hasExtension ( const SLstring & e )

inline

◆ hasMultiSampling()

bool SLGLState::hasMultiSampling ( ) const

inline

◆ initAll()

void SLGLState::initAll ( )

Initializes all states.

◆ instance()

static SLGLState * SLGLState::instance ( )

inlinestatic

Public static instance getter for singleton pattern.

◆ multiSample()

void SLGLState::multiSample ( SLbool stateNew )

SLGLState::multiSample enables or disables multisampling but only if the state really changes. Multisampling turns on fullscreen anti aliasing on the GPU witch produces smooth polygon edges, lines and points.

◆ onInitialize()

void SLGLState::onInitialize ( const SLCol4f & clearColor )

On init GL.

One time initialization

◆ pixelFormatIsSupported()

SLbool SLGLState::pixelFormatIsSupported ( SLint pixelFormat )

Returns true if the according GL pixel format is valid in the GL context.

◆ polygonLine()

void SLGLState::polygonLine ( SLbool stateNew )

SLGLState::polygonMode sets the polygonMode to GL_LINE but only if the state really changes. OpenGL ES doesn't support glPolygonMode. It has to be mimicked with GL_LINE_LOOP drawing.

◆ polygonOffsetFill()

void SLGLState::polygonOffsetFill	(	SLbool	enabled,
		SLfloat	factor = `-1.0f`,
		SLfloat	units = `-1.0f`
	)

SLGLState::polygonOffsetFill turns on/off polygon offset for filled polygons and sets the factor and unit for glPolygonOffset but only if the state really changes. Polygon offset is used to reduce z-fighting due to parallel planes or lines. See: http://www.zeuscmd.com/tutorials/opengl/15-PolygonOffset.php

◆ polygonOffsetLine()

void SLGLState::polygonOffsetLine	(	SLbool	enabled,
		SLfloat	factor = `-1.0f`,
		SLfloat	units = `-1.0f`
	)

SLGLState::polygonOffsetLine turns on/off polygon offset for lines and sets the factor and unit for glPolygonOffset but only if the state really changes. Polygon offset is used to reduce z-fighting due to parallel planes or lines. See: http://www.zeuscmd.com/tutorials/opengl/15-PolygonOffset.php

◆ polygonOffsetPoint()

void SLGLState::polygonOffsetPoint	(	SLbool	enabled,
		SLfloat	factor = `-1.0f`,
		SLfloat	units = `-1.0f`
	)

SLGLState::polygonOffsetPoint turns on/off polygon offset for points and sets the factor and unit for glPolygonOffset but only if the state really changes. Polygon offset is used to reduce z-fighting due to parallel planes or lines. See: http://www.zeuscmd.com/tutorials/opengl/15-PolygonOffset.php

◆ readPixels()

void SLGLState::readPixels ( void * buffer )

Reads the front framebuffer pixels into the passed buffer.

Parameters

buffer Pointer to a 4 byte aligned buffer with the correct size.

◆ unbindAnythingAndFlush()

void SLGLState::unbindAnythingAndFlush ( )

finishes all GL commands

SLGLState::unbindAnythingAndFlush unbinds all shaderprograms and buffers in use and calls glFinish. This should be the last call to GL before buffer swapping.

◆ useProgram()

void SLGLState::useProgram ( SLuint progID )

SLGLState::useProgram sets the _rent active shader program

◆ viewport() [1/2]

SLVec4i SLGLState::viewport ( )

inline

◆ viewport() [2/2]

void SLGLState::viewport	(	SLint	x,
		SLint	y,
		SLsizei	width,
		SLsizei	height
	)

SLGLState::viewport sets the OpenGL viewport position and size

◆ viewportMatrix()

SLMat4f SLGLState::viewportMatrix ( )

inline

Member Data Documentation

◆ _blend

SLbool SLGLState::_blend

private

blending default false;

◆ _blendFuncDfactor

SLenum SLGLState::_blendFuncDfactor

private

blend function destination factor enum

◆ _blendFuncSfactor

SLenum SLGLState::_blendFuncSfactor

private

blend function source factor enum

◆ _clearColor

SLCol4f SLGLState::_clearColor

private

clear color

◆ _colorMaskA

GLboolean SLGLState::_colorMaskA

private

current color mask for A

◆ _colorMaskB

GLboolean SLGLState::_colorMaskB

private

current color mask for B

◆ _colorMaskG

GLboolean SLGLState::_colorMaskG

private

current color mask for G

◆ _colorMaskR

GLboolean SLGLState::_colorMaskR

private

current color mask for R

◆ _cullFace

SLbool SLGLState::_cullFace

private

Face culling state.

◆ _currentMaterial

SLMaterial* SLGLState::_currentMaterial

private

◆ _depthFunc

SLenum SLGLState::_depthFunc

private

depth buffer comparison function

◆ _depthMask

SLbool SLGLState::_depthMask

private

glDepthMask state

◆ _depthTest

SLbool SLGLState::_depthTest

private

GL_DEPTH_TEST state.

◆ _glExtensions

SLstring SLGLState::_glExtensions

private

OpenGL extensions string.

◆ _glIsES2

SLbool SLGLState::_glIsES2

private

Flag if OpenGL ES2.

◆ _glIsES3

SLbool SLGLState::_glIsES3

private

Flag if OpenGL ES3.

◆ _glMaxTexSize

SLint SLGLState::_glMaxTexSize

private

glGetIntegerv(GL_MAX_TEXTURE_SIZE, &_glMaxTexSize);

◆ _glMaxTexUnits

SLint SLGLState::_glMaxTexUnits

private

glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &_glMaxTexUnits);

◆ _glRenderer

SLstring SLGLState::_glRenderer

private

OpenGL Renderer string.

◆ _glSLVersion

SLstring SLGLState::_glSLVersion

private

GLSL Version string.

◆ _glSLVersionNO

SLstring SLGLState::_glSLVersionNO

private

GLSL Version number string.

◆ _glVendor

SLstring SLGLState::_glVendor

private

OpenGL Vendor string.

◆ _glVersion

SLstring SLGLState::_glVersion

private

OpenGL Version string.

◆ _glVersionNO

SLstring SLGLState::_glVersionNO

private

OpenGL Version number string.

◆ _glVersionNOf

SLfloat SLGLState::_glVersionNOf

private

OpenGL Version number as float.

◆ _instance

SLGLState * SLGLState::_instance = nullptr

staticprivate

global singleton object

◆ _isInitialized

SLbool SLGLState::_isInitialized

private

flag for first init

◆ _multisample

SLbool SLGLState::_multisample

private

Multisampling state.

◆ _multiSampleSamples

SLint SLGLState::_multiSampleSamples

private

NO. of multisampling samples.

◆ _polygonLine

SLbool SLGLState::_polygonLine

private

Line polygon state.

◆ _polygonOffsetFillEnabled

SLbool SLGLState::_polygonOffsetFillEnabled

private

GL_POLYGON_OFFSET_FILL state enabled.

◆ _polygonOffsetLineEnabled

SLbool SLGLState::_polygonOffsetLineEnabled

private

GL_POLYGON_OFFSET_LINE state enabled.

◆ _polygonOffsetPointEnabled

SLbool SLGLState::_polygonOffsetPointEnabled

private

GL_POLYGON_OFFSET_POINT state enabled.

◆ _programID

SLuint SLGLState::_programID

private

current shader program id

◆ _textureID

SLuint SLGLState::_textureID

private

current texture id

◆ _textureTarget

SLenum SLGLState::_textureTarget

private

current texture target

◆ _textureUnit

SLenum SLGLState::_textureUnit

private

current texture unit

◆ _viewport

SLVec4i SLGLState::_viewport

private

viewport size (x,y,w,h) of the framebuffer

◆ errors

SLVstring SLGLState::errors

private

vector for errors collected in getGLError

◆ modelMatrix

SLMat4f SLGLState::modelMatrix

Init all states.

matrix for model to world transform

◆ projectionMatrix

SLMat4f SLGLState::projectionMatrix

matrix for projection transform

◆ textureMatrix

SLMat4f SLGLState::textureMatrix

matrix for the texture transform

◆ viewMatrix

SLMat4f SLGLState::viewMatrix

matrix for the active cameras view transform

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

Public Member Functions

Static Public Member Functions

Public Attributes

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SLGLState()

◆ ~SLGLState()

Member Function Documentation

◆ activeTexture()

◆ bindTexture()

◆ blend() [1/2]

◆ blend() [2/2]

◆ blendFunc()

◆ clearColor()

◆ clearColorBuffer()

◆ clearColorDepthBuffer()

◆ clearDepthBuffer()

◆ colorMask()

◆ cullFace()

◆ currentMaterial() [1/2]

◆ currentMaterial() [2/2]

◆ deleteInstance()

◆ depthFunc()

◆ depthMask()

◆ depthTest()

◆ getGLError()

◆ getGLVersionNO()

◆ getSLVersionNO()

◆ glHasGeometryShaders()

◆ glIsES()

◆ glIsES2()

◆ glIsES3()

◆ glMaxTexSize()

◆ glMaxTexUnits()

◆ glRenderer()

◆ glSLVersion()

◆ glSLVersionNO()

◆ glVendor()

◆ glVersion()

◆ glVersionNO()

◆ glVersionNOf()

◆ hasExtension()

◆ hasMultiSampling()

◆ initAll()

◆ instance()

◆ multiSample()

◆ onInitialize()

◆ pixelFormatIsSupported()

◆ polygonLine()

◆ polygonOffsetFill()

◆ polygonOffsetLine()

◆ polygonOffsetPoint()

◆ readPixels()

◆ unbindAnythingAndFlush()

◆ useProgram()

◆ viewport() [1/2]

◆ viewport() [2/2]

◆ viewportMatrix()

Member Data Documentation

◆ _blend

◆ _blendFuncDfactor

◆ _blendFuncSfactor

◆ _clearColor

◆ _colorMaskA

◆ _colorMaskB

◆ _colorMaskG

◆ _colorMaskR

◆ _cullFace

◆ _currentMaterial

◆ _depthFunc

◆ _depthMask

◆ _depthTest

◆ _glExtensions

◆ _glIsES2

◆ _glIsES3

◆ _glMaxTexSize

◆ _glMaxTexUnits