| '''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 |
| ) |
| |
