| | '''OpenGL extension SGIX.async |
| | |
| | This module customises the behaviour of the |
| | OpenGL.raw.GL.SGIX.async to provide a more |
| | Python-friendly API |
| | |
| | Overview (from the spec) |
| | |
| | This extension provides a framework for asynchronous OpenGL |
| | commands. It also provides commands allowing a program to wait |
| | for the completion of asynchronous commands. |
| | |
| | Asynchronous commands have two properties: |
| | |
| | 1) Asynchronous commands are non-blocking. For example, an |
| | asynchronous ReadPixels command returns control to the program |
| | immediately rather than blocking until the command completes. |
| | This property allows the program to issue other OpenGL commands in |
| | parallel with the execution of commands that normally block. |
| | |
| | 2) Asynchronous commands may complete out-of-order with respect to |
| | other OpenGL commands. For example, an asynchronous TexImage |
| | command may complete after subsequent OpenGL commands issued by |
| | the program rather than maintaining the normal serial order of the |
| | OpenGL command stream. This property allows the graphics |
| | accelerator to execute asynchronous commands in parallel with the |
| | normal command stream, for instance using a secondary path to |
| | transfer data from or to the host, without doing any dependency |
| | checking. |
| | |
| | Programs that issue asynchronous commands must also be able to |
| | determine when the commands have completed. The completion status |
| | may be needed so that results can be retrieved (e.g. the image |
| | data from a ReadPixels command) or so that dependent commands can |
| | be issued (e.g. drawing commands that use texture data downloaded |
| | by an earlier asynchronous command). This extension provides |
| | fine-grain control over asynchronous commands by introducing a |
| | mechanism for determining the status of individual commands. |
| | |
| | Each invocation of an asynchronous command is associated with an |
| | integer called a "marker." A program specifies a marker before it |
| | issues an asynchronous command. The program may later issue a |
| | command to query if any asynchronous commands have completed. The |
| | query commands return a marker to identify the command that |
| | completed. This extension provides both blocking and non-blocking |
| | query commands. |
| | |
| | This extension does not define any asynchronous commands. |
| | See SGIX_async_pixel for the asynchronous pixel commands. |
| | |
| | The official definition of this extension is available here: |
| | http://www.opengl.org/registry/specs/SGIX/async.txt |
| | ''' |
| | from OpenGL import platform, constant, arrays |
| | from OpenGL import extensions, wrapper |
| | import ctypes |
| | from OpenGL.raw.GL import _types, _glgets |
| | from OpenGL.raw.GL.SGIX.async import * |
| | from OpenGL.raw.GL.SGIX.async import _EXTENSION_NAME |
| |
|
| | def glInitAsyncSGIX(): |
| | '''Return boolean indicating whether this extension is available''' |
| | from OpenGL import extensions |
| | return extensions.hasGLExtension( _EXTENSION_NAME ) |
| |
|
| | glFinishAsyncSGIX=wrapper.wrapper(glFinishAsyncSGIX).setOutput( |
| | 'markerp',size=(1,),orPassIn=True |
| | ) |
| | glPollAsyncSGIX=wrapper.wrapper(glPollAsyncSGIX).setOutput( |
| | 'markerp',size=(1,),orPassIn=True |
| | ) |
| | |
