OpenGL extension NV.fence
This module customises the behaviour of the
OpenGL.raw.GL.NV.fence to provide a more
Overview (from the spec)
The goal of this extension is provide a finer granularity of
synchronizing GL command completion than offered by standard OpenGL,
which offers only two mechanisms for synchronization: Flush and Finish.
Since Flush merely assures the user that the commands complete in a
finite (though undetermined) amount of time, it is, thus, of only
modest utility. Finish, on the other hand, stalls CPU execution
until all pending GL commands have completed. This extension offers
a middle ground - the ability to "finish" a subset of the command
stream, and the ability to determine whether a given command has
completed or not.
This extension introduces the concept of a "fence" to the OpenGL
command stream. Once the fence is inserted into the command stream, it
can be queried for a given condition - typically, its completion.
Moreover, the application may also request a partial Finish -- that is,
all commands prior to the fence will be forced to complete until control
is returned to the calling process. These new mechanisms allow for
synchronization between the host CPU and the GPU, which may be accessing
the same resources (typically memory).
This extension is useful in conjunction with NV_vertex_array_range
to determine when vertex information has been pulled from the
vertex array range. Once a fence has been tested TRUE or finished,
all vertex indices issued before the fence must have been pulled.
This ensures that the vertex data memory corresponding to the issued
vertex indices can be safely modified (assuming no other outstanding
vertex indices are issued subsequent to the fence).
The official definition of this extension is available here:
|EXTENSION_NAME = 'GL_NV_fence'|
GL_ALL_COMPLETED_NV = GL_ALL_COMPLETED_NV
GL_FENCE_CONDITION_NV = GL_FENCE_CONDITION_NV
GL_FENCE_STATUS_NV = GL_FENCE_STATUS_NV
__file__ = '/home/mcfletch/pylive/OpenGL/GL/NV/fence.pyc'
__name__ = 'OpenGL.GL.NV.fence'
__package__ = 'OpenGL.GL.NV'
glDeleteFencesNV = <OpenGL.platform.baseplatform.glDeleteFencesNV object at 0x78df7d0>
glFinishFenceNV = <OpenGL.platform.baseplatform.glFinishFenceNV object at 0x78dfb10>
glGenFencesNV = <OpenGL.platform.baseplatform.glGenFencesNV object at 0x78df810>
glGetFenceivNV = <OpenGL.platform.baseplatform.glGetFenceivNV object at 0x78dfa10>
glIsFenceNV = <OpenGL.platform.baseplatform.glIsFenceNV object at 0x78df910>
glSetFenceNV = <OpenGL.platform.baseplatform.glSetFenceNV object at 0x78dfb50>
glTestFenceNV = <OpenGL.platform.baseplatform.glTestFenceNV object at 0x78df9d0>