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