OpenGL extension EXT.separate_shader_objects
This module customises the behaviour of the
OpenGL.raw.GL.EXT.separate_shader_objects to provide a more
Overview (from the spec)
Prior to this extension, GLSL requires multiple shader domains
(vertex, fragment, geometry) to be linked into a single monolithic
program object to specify a GLSL shader for each domain.
While GLSL's monolithic approach has some advantages for
optimizing shaders as a unit that span multiple domains, all
existing GPU hardware supports the more flexible mix-and-match
HLSL9, Cg, the prior OpenGL assembly program extensions, and game
console programmers favor a more flexible "mix-and-match" approach to
specifying shaders independently for these different shader domains.
Many developers build their shader content around the mix-and-match
approach where they can use a single vertex shader with multiple
fragment shaders (or vice versa).
This keep-it-simple extension adapts the "mix-and-match" shader
domain model for GLSL so different GLSL program objects can be bound
to different shader domains.
This extension redefines the operation of glUseProgram(GLenum program)
to be equivalent to:
You can also call these commands separately to bind each respective
domain. The GL_VERTEX_SHADER, GL_GEOMETRY_SHADER_EXT, and
GL_FRAGMENT_SHADER tokens refer to the conventional vertex, geometry,
and fragment domains respectively. glActiveProgramEXT specifies
the program that glUniform* commands will update.
Separate linking creates the possibility that certain output varyings
of a shader may go unread by the subsequent shader inputting varyings.
In this case, the output varyings are simply ignored. It is also
possible input varyings from a shader may not be written as output
varyings of a preceding shader. In this case, the unwritten input
varying values are undefined. Implementations are encouraged to
zero these undefined input varying values.
This extension is a proof-of-concept that separate shader objects
can work for GLSL and a response to repeated requests for this
functionality. There are various loose ends, particularly when
dealing with user-defined varyings. The hope is a future extension
will improve this situation.
The official definition of this extension is available here:
|EXTENSION_NAME = 'GL_EXT_separate_shader_objects'|
GL_ACTIVE_PROGRAM_EXT = GL_ACTIVE_PROGRAM_EXT
__file__ = '/home/mcfletch/pylive/OpenGL/GL/EXT/separate_shader_objects.pyc'
__name__ = 'OpenGL.GL.EXT.separate_shader_objects'
__package__ = 'OpenGL.GL.EXT'
glActiveProgramEXT = <OpenGL.platform.baseplatform.glActiveProgramEXT object at 0x76ea1d0>
glCreateShaderProgramEXT = <OpenGL.platform.baseplatform.glCreateShaderProgramEXT object at 0x76ea210>
glUseShaderProgramEXT = <OpenGL.platform.baseplatform.glUseShaderProgramEXT object at 0x76ea110>