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