| '''OpenGL extension OML.subsample |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GL.OML.subsample to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| Many video image formats and compression techniques utilize various |
| component subsamplings, so it is necessary to provide a mechanism to |
| specify the up- and down-sampling of components as pixel data is |
| drawn from and read back to the client. Though subsampled components |
| are normally associated with the video color space, YCrCb, use of |
| subsampling in OpenGL does not imply a specific color space. Color |
| space conversion may be performed using other extensions or core |
| capabilities such as the color matrix. |
| |
| This extension defines two new pixel storage formats representing |
| subsampled data on the client. It is loosely based on the |
| SGIX_subsample extension, but specifies subsampling with the data |
| format parameter rather than pixel packing parameters. It also |
| adds support for CYA subsampled data. |
| |
| When pixel data is received from the client and an unpacking |
| upsampling mode other than PIXEL_SUBSAMPLE_NONE_OML is specified, |
| upsampling is performed via replication, unless otherwise specified |
| by UNPACK_RESAMPLE_OML. |
| |
| Similarly, when pixel data is read back to the client and a packing |
| downsampling mode other than PIXEL_SUBSAMPLE_NONE_OML is specified, |
| downsampling is performed via simple component decimation (point |
| sampling), unless otherwise specified by PACK_RESAMPLE_OML. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/OML/subsample.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.OML.subsample import * |
| from OpenGL.raw.GL.OML.subsample import _EXTENSION_NAME |
|
|
| def glInitSubsampleOML(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
|
|
| |
| from OpenGL import images as _i |
| _i.COMPONENT_COUNTS[ GL_FORMAT_SUBSAMPLE_24_24_OML ] = 1 |
| _i.COMPONENT_COUNTS[ GL_FORMAT_SUBSAMPLE_244_244_OML ] = 1 |
|
|
