| '''OpenGL extension ARB.indirect_parameters |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GL.ARB.indirect_parameters to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| OpenGL 4.3 (with the introduction of the GL_ARB_multi_draw_indirect |
| extension) enhanced the ability of OpenGL to allow a large sets of |
| parameters for indirect draws (introduced with OpenGL 4.0) into a buffer |
| object and dispatch the entire list with one API call. This allows, for |
| example, a shader (such as a compute shader via shader storage buffers, |
| or a geometry shader via transform feedback) to produce lists of draw |
| commands that can then be consumed by OpenGL without a server-client |
| round trip. However, when a variable and potentially unknown number of |
| draws are produced by such a shader, it becomes difficult to know how |
| many draws are in the output array(s). Applications must resort to |
| techniques such as transform feedback primitive queries, or mapping |
| buffers containing the content of atomic counters, which can cause stalls |
| or bubbles in the OpenGL pipeline. |
| |
| This extension introduces the concept of the "parameter buffer", which |
| is a target allowing buffers to store parameters for certain drawing |
| commands. Also in this extension, new variants of MultiDrawArraysIndirect |
| and MultiDrawElementsIndirect are introduced that source some of their |
| parameters from this buffer. Further commands could potentially be |
| introduced that source other parameters from a buffer. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/ARB/indirect_parameters.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.indirect_parameters import * |
| from OpenGL.raw.GL.ARB.indirect_parameters import _EXTENSION_NAME |
|
|
| def glInitIndirectParametersARB(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
|
|
| |
