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glAsync Namespace Reference

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Detailed Description

Provides asynchronous OpenGL functions.

The glAsync functions deliver asynchronous OpenGL downloads in the spirit of the SGIX_async extension. The asynchronous execution of certain rendering commands can improve the overall performance of the application. The ARB_sync extension provides now a better way for asynchronous operations.

A second thread uses a shared context to the main context for asynchronous downloads. The application can map more than one context, but only one context can be current at a given time. All commands are executed in the order they are submitted. The asynchronous helper thread is only running when at least one context is mapped.

The functions are not thread-safe. For thread-safety and performance multi-threaded rendering codes are advised to use one glAsync::Thread instance per rendering thread.

Classes
class	Thread
	For multi-threaded rendering, use one instance of this class for each rendering thread. More...
Functions
Bool	XMapContext (Display *display, XVisualInfo *visInfo, GLXContext context)
	Map a context to be used for asynchronous functions.
void	XUnmapContext (Display *display, GLXContext context)
	Unmap a context to be used for asynchronous functions.
Bool	XMakeCurrent (Display *display, GLXContext context)
	Attach a rendering context to the asynchronous thread.
void	bindTexture (GLenum target, GLuint texture)
	Bind a named texture to a texturing target for the following asynchronous texture operations on the target.
GLuint	texImage2D (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid *pixels)
	Specify a two-dimensional texture image.
GLuint	texImage3D (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, const GLvoid *pixels)
	Specify a three-dimensional texture image.
Bool	poll (GLuint marker)
	Poll for the completion of an operation.
Bool	isIdle ()
	Poll for the completion of all operations.
void	finish (GLuint marker)
	Finish an operation.
void	finishAll ()
	Finish all pending operations.

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Function Documentation

Bool glAsync::XMapContext	(	Display *	display,
		XVisualInfo *	visInfo,
		GLXContext	context
	)

Map a context to be used for asynchronous functions.

This function creates a hidden shared context and drawable to be used the asynchronous functions.

Parameters:

	display	the connection to the X server.
	visInfo	the visual information.
	context	the GLX rendering context.

Returns:

True on success, False otherwise.

void glAsync::XUnmapContext	(	Display *	display,
		GLXContext	context
	)

Unmap a context to be used for asynchronous functions.

This function deregisters the context from the glAsync library and deallocates all associated resources. For performance reasons it does not check that all outstanding commands for this context have been executed. The application has to explicitly wait for the commands to be finished before calling the function.

Parameters:

	display	the connection to the X server.
	context	the GLX rendering context.

See also:

finish(), finishAll()

Bool glAsync::XMakeCurrent	(	Display *	display,
		GLXContext	context
	)

Attach a rendering context to the asynchronous thread.

Parameters:

	display	the connection to the X server.
	context	the GLX rendering context.

Returns:

True if successful, False otherwise.

See also:

glXMakeCurrent

void glAsync::bindTexture	(	GLenum	target,
		GLuint	texture
	)

Bind a named texture to a texturing target for the following asynchronous texture operations on the target.

See also:

glBindTexture

GLuint glAsync::texImage2D	(	GLenum	target,
		GLint	level,
		GLint	internalformat,
		GLsizei	width,
		GLsizei	height,
		GLint	border,
		GLenum	format,
		GLenum	type,
		const GLvoid *	pixels
	)

Specify a two-dimensional texture image.

Returns:

the marker associated with the asynchronous operation.

See also:

glTexImage2D

GLuint glAsync::texImage3D	(	GLenum	target,
		GLint	level,
		GLint	internalformat,
		GLsizei	width,
		GLsizei	height,
		GLsizei	depth,
		GLint	border,
		GLenum	format,
		GLenum	type,
		const GLvoid *	pixels
	)

Specify a three-dimensional texture image.

Returns:

the marker associated with the asynchronous operation.

See also:

glTexImage3D

Bool glAsync::poll

(

GLuint

marker

)

Poll for the completion of an operation.

Parameters:

marker

the marker of the operation.

Returns:

True if the operation has completed, False if it is in progress.

Bool glAsync::isIdle

(

)

Poll for the completion of all operations.

Returns:

True if the helper thread is idle, i.e. all operations have completed, False if there are still outstanding operations.

void glAsync::finish

(

GLuint

marker

)

Finish an operation.

Finish blocks until the operation has completed.

Parameters:

marker

the marker of the operation.

void glAsync::finishAll

(

)

Finish all pending operations.

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