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'''OpenGL extension SGIX.instruments |
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This module customises the behaviour of the |
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OpenGL.raw.GL.SGIX.instruments 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 allows the gathering and return of performance |
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measurements from within the graphics pipeline by adding |
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instrumentation. |
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There are two reasons to do this. The first is as a part of some |
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type of fixed-frame-rate load management scheme. If we know that |
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the pipeline is stalled or struggling to process the amount of |
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data we have given it so far, we can reduce the level of detail of |
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the remaining objects in the current frame or the next frame, or |
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adjust the framebuffer resolution for the next frame if we have a |
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video-zoom capability available. We can call this type of |
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instrumentation Load Monitoring. |
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The second is for performance tuning and debugging of an |
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application. It might tell us how many triangles were culled or |
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clipped before being rasterized. We can call this simply Tuning. |
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Load Monitoring requires that the instrumentation and the access |
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of the measurements be efficient, otherwise the instrumentation |
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itself will reduce performance more than any load-management |
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scheme could hope to offset. Tuning does not have the same |
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requirements. |
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The proposed extension adds a call to setup a measurements return |
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buffer, similar to FeedbackBuffer but with an asynchrounous |
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behavior to prevent filling the pipeline with NOP's while waiting |
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for the data to be returned. |
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Note that although the extension has been specified without any |
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particular instruments, defining either a device dependent or |
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device independent instrument should be as simple as introducing |
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an extension consisting primarily of a new enumerant to identify |
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the instrument. |
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The official definition of this extension is available here: |
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http://www.opengl.org/registry/specs/SGIX/instruments.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.instruments import * |
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from OpenGL.raw.GL.SGIX.instruments import _EXTENSION_NAME |
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def glInitInstrumentsSGIX(): |
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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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glInstrumentsBufferSGIX=wrapper.wrapper(glInstrumentsBufferSGIX).setOutput( |
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'buffer',size=lambda x:(x,),pnameArg='size',orPassIn=True |
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) |
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glPollInstrumentsSGIX=wrapper.wrapper(glPollInstrumentsSGIX).setOutput( |
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'marker_p',size=(1,),orPassIn=True |
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) |
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