globjects::Query Class Reference

Encapsulates a GL Query object. More...

#include <globjects/include/globjects/Query.h>

Inheritance diagram for globjects::Query:

Public Member Functions
	Query ()
virtual	~Query ()
virtual void	accept (ObjectVisitor &visitor) override
void	begin (gl::GLenum target) const
void	end (gl::GLenum target) const
void	beginIndexed (gl::GLenum target, gl::GLuint index) const
void	endIndexed (gl::GLenum target, gl::GLuint index) const
gl::GLuint	get (gl::GLenum pname) const
gl::GLuint64	get64 (gl::GLenum pname) const
bool	resultAvailable () const
void	wait () const
void	wait (const std::chrono::duration< int, std::nano > &timeout) const
gl::GLuint	waitAndGet (gl::GLenum pname) const
gl::GLuint64	waitAndGet64 (gl::GLenum pname) const
gl::GLuint	waitAndGet (const std::chrono::duration< int, std::nano > &timeout, gl::GLenum pname) const
gl::GLuint64	waitAndGet64 (const std::chrono::duration< int, std::nano > &timeout, gl::GLenum pname) const
gl::GLuint	waitAndGet (gl::GLenum pname, const std::chrono::duration< int, std::nano > &timeout) const
gl::GLuint64	waitAndGet64 (gl::GLenum pname, const std::chrono::duration< int, std::nano > &timeout) const
void	counter () const
virtual gl::GLenum	objectType () const override
Public Member Functions inherited from globjects::Object
gl::GLuint	id () const
std::string	name () const
void	setName (const std::string &name)
bool	hasName () const
bool	isDefault () const
void	detach ()

Static Public Member Functions
static std::unique_ptr< Query >	fromId (gl::GLuint id)
static std::unique_ptr< Query >	current (gl::GLenum target)
static std::unique_ptr< Query >	timestamp ()
static gl::GLint	get (gl::GLenum target, gl::GLenum pname)
static gl::GLint	getIndexed (gl::GLenum target, gl::GLuint index, gl::GLenum pname)
static gl::GLint	getCounterBits (gl::GLenum target)
static bool	isQuery (gl::GLuint id)
Static Public Member Functions inherited from globjects::Object
static void	hintNameImplementation (NameImplementation impl)
Static Public Member Functions inherited from globjects::Instantiator< Query >
static std::unique_ptr< Query >	create (Args &&...args)
static std::unique_ptr< Query >	fromId (gl::GLuint id, Args &&...args)

Protected Member Functions
	Query (std::unique_ptr< IDResource > &&resource)
void	counter (gl::GLenum target) const
Protected Member Functions inherited from globjects::Object
	Object (std::unique_ptr< IDResource > &&resource)
virtual	~Object ()

Static Protected Member Functions
static gl::GLuint	genQuery ()

Additional Inherited Members
Public Types inherited from globjects::Object
enum	NameImplementation { NameImplementation::DebugKHR, NameImplementation::Legacy }
Protected Attributes inherited from globjects::Object
std::unique_ptr< IDResource >	m_resource
void *	m_objectLabelState

Detailed Description

Encapsulates a GL Query object.

A Query object is used to query different aspects of the rendering pipeline, such as passed samples, generated primitives, written transform feedback primitives or elapsed time. With begin() and end(), the scope of the measurements could be specified. As a Query object queries the GPU asynchroneously, the result won't be available right after the end() invokation. The resultAvailable() method indicates whether the calling of get()/get64() will return the final result. To wait until the result is available, the wait() method can be used. Alternatively there are waitAndGet() and waitAndGet64() to query the result in one invokation.

There is a convenience method to create a Query object which answeres with the current timestamp on the GPU named timestamp() (see example below).

An example time measurement:

std::unique_ptr<Query> query = Query::create(gl::GL_TIME_ELAPSED);
query->begin();

// more GL calls

query->end();

query->wait();
gl::GLuint timeElapsed = query->get();
// Note: sometimes it's important to use the 64 bit equivalent, because the 32 bit version can only capture time up to 4 seconds.

An example timestamp access:

// GL calls

std::unique_ptr<Query> query = Query::timestamp();

// even more GL calls

query->wait();
gl::GLuint64 timestamp = query->get64();
// Note: the result is the timestamp on the GPU right after the first GL calls finished and before the second calls started.

See also

http://www.opengl.org/wiki/Query_Object

http://www.opengl.org/registry/specs/ARB/timer_query.txt

Constructor & Destructor Documentation

globjects::Query::Query

(

)

virtual globjects::Query::~Query ( )

virtual

globjects::Query::Query ( std::unique_ptr< IDResource > &&  resource )

protected

Member Function Documentation

static std::unique_ptr<Query> globjects::Query::fromId ( gl::GLuint  id )

static

static std::unique_ptr<Query> globjects::Query::current ( gl::GLenum  target )

static

static std::unique_ptr<Query> globjects::Query::timestamp ( )

static

static gl::GLint globjects::Query::get ( gl::GLenum  target, gl::GLenum  pname  )

static

static gl::GLint globjects::Query::getIndexed ( gl::GLenum  target, gl::GLuint  index, gl::GLenum  pname  )

static

static gl::GLint globjects::Query::getCounterBits ( gl::GLenum  target )

static

virtual void globjects::Query::accept ( ObjectVisitor &  visitor )

overridevirtual

Implements globjects::Object.

void globjects::Query::begin

(

gl::GLenum

target

)

const

void globjects::Query::end

(

gl::GLenum

target

)

const

void globjects::Query::beginIndexed	(	gl::GLenum	target,
		gl::GLuint	index
	)		const

void globjects::Query::endIndexed	(	gl::GLenum	target,
		gl::GLuint	index
	)		const

static bool globjects::Query::isQuery ( gl::GLuint  id )

static

gl::GLuint globjects::Query::get

(

gl::GLenum

pname

)

const

gl::GLuint64 globjects::Query::get64

(

gl::GLenum

pname

)

const

bool globjects::Query::resultAvailable

(

)

const

void globjects::Query::wait

(

)

const

void globjects::Query::wait

(

const std::chrono::duration< int, std::nano > &

timeout

)

const

gl::GLuint globjects::Query::waitAndGet

(

gl::GLenum

pname

)

const

gl::GLuint64 globjects::Query::waitAndGet64

(

gl::GLenum

pname

)

const

gl::GLuint globjects::Query::waitAndGet	(	const std::chrono::duration< int, std::nano > &	timeout,
		gl::GLenum	pname
	)		const

gl::GLuint64 globjects::Query::waitAndGet64	(	const std::chrono::duration< int, std::nano > &	timeout,
		gl::GLenum	pname
	)		const

gl::GLuint globjects::Query::waitAndGet	(	gl::GLenum	pname,
		const std::chrono::duration< int, std::nano > &	timeout
	)		const

gl::GLuint64 globjects::Query::waitAndGet64	(	gl::GLenum	pname,
		const std::chrono::duration< int, std::nano > &	timeout
	)		const

void globjects::Query::counter

(

)

const

virtual gl::GLenum globjects::Query::objectType ( ) const

overridevirtual

Implements globjects::Object.

static gl::GLuint globjects::Query::genQuery ( )

staticprotected

void globjects::Query::counter ( gl::GLenum  target ) const

protected

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

• Query.h