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'''OpenGL extension ARB.transform_feedback3
This module customises the behaviour of the
OpenGL.raw.GL.ARB.transform_feedback3 to provide a more
Python-friendly API
Overview (from the spec)
This extension further extends the transform feedback capabilities
provided by the EXT_transform_feedback, NV_transform_feedback, and
NV_transform_feedback2 extensions. Those extensions provided a new
transform feedback mode, where selected vertex attributes can be recorded
to a buffer object for each primitive processed by the GL.
This extension provides increased flexibility in how vertex attributes can
be written to buffer objects. Previous extensions allowed applications to
record a set of attributes interleaved into a single buffer object
(interleaved mode) or to record into multiple objects, but with only a
single attribute per buffer (separate mode). This extension extends
interleaved mode to write into multiple buffers, with multiple attributes
per buffer. This capability is supported for all three styles of
transform feedback:
- "EXT"-style GLSL transform feedback (EXT_transform_feedback), where a
list of varyings is provided prior to linking a program object and is
used whenever that program object is used.
- "NV"-style GLSL transform feedback (NV_transform_feedback), where
"locations" of active varyings are queried after linking and are then
passed to a function that sets the active transform feedback varyings
for the program object. Unlike the "EXT"-style mode, the set of
varyings to capture can be changed without relinking.
- Transform feedback for fixed-function or assembly vertex/geometry
shaders (NV_transform_feedback), where applications specify a set of
canonical attribute enums/numbers to capture.
Additionally, this extension adds new support for multiple separate
vertex streams. New geometry shader functionality provided by the
ARB_gpu_shader5 and NV_gpu_program5 extensions allows geometry shaders
to direct each vertex arbitrarily at a specified vertex stream. For
example, a geometry program might write each "regular" vertex it emits
to one vertex stream while writing some per-primitive data it computes
to a second vertex stream. This extension allows applications to
choose a vertex stream for each buffer object it writes to, and allows
the vertices written to each vertex stream to be recorded in separate
buffer objects. Only one stream may be selected for rasterization,
and in the initial implementation, the geometry shader output topology
must be POINTS if multiple streams are used. When geometry shaders
are not used, or when an old geometry shader not writing multiple
streams is used, all vertices produced by the GL are directed at the
stream numbered zero. The set of transform feedback-related query
targets is extended to accommodate multiple vertex streams, so it is
possible to count the number of processed and recorded primitives for
each stream separately.
The official definition of this extension is available here:
http://www.opengl.org/registry/specs/ARB/transform_feedback3.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.ARB.transform_feedback3 import *
from OpenGL.raw.GL.ARB.transform_feedback3 import _EXTENSION_NAME
def glInitTransformFeedback3ARB():
'''Return boolean indicating whether this extension is available'''
from OpenGL import extensions
return extensions.hasGLExtension( _EXTENSION_NAME )
glGetQueryIndexediv=wrapper.wrapper(glGetQueryIndexediv).setOutput(
'params',size=_glgets._glget_size_mapping,pnameArg='pname',orPassIn=True
)
### END AUTOGENERATED SECTION
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