| '''OpenGL extension SGIS.texture_lod |
| |
| This module customises the behaviour of the |
| OpenGL.raw.GL.SGIS.texture_lod to provide a more |
| Python-friendly API |
| |
| Overview (from the spec) |
| |
| This extension imposes two constraints related to the texture level of |
| detail parameter LOD, which is represented by the Greek character lambda |
| in the GL Specification. One constraint clamps LOD to a specified |
| floating point range. The other limits the selection of mipmap image |
| arrays to a subset of the arrays that would otherwise be considered. |
| |
| Together these constraints allow a large texture to be loaded and |
| used initially at low resolution, and to have its resolution raised |
| gradually as more resolution is desired or available. Image array |
| specification is necessarily integral, rather than continuous. By |
| providing separate, continuous clamping of the LOD parameter, it is |
| possible to avoid "popping" artifacts when higher resolution images |
| are provided. |
| |
| Note: because the shape of the mipmap array is always determined by |
| the dimensions of the level 0 array, this array must be loaded for |
| mipmapping to be active. If the level 0 array is specified with a |
| null image pointer, however, no actual data transfer will take |
| place. And a sufficiently tuned implementation might not even |
| allocate space for a level 0 array so specified until true image |
| data were presented. |
| |
| The official definition of this extension is available here: |
| http://www.opengl.org/registry/specs/SGIS/texture_lod.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.SGIS.texture_lod import * |
| from OpenGL.raw.GL.SGIS.texture_lod import _EXTENSION_NAME |
|
|
| def glInitTextureLodSGIS(): |
| '''Return boolean indicating whether this extension is available''' |
| from OpenGL import extensions |
| return extensions.hasGLExtension( _EXTENSION_NAME ) |
|
|
|
|
| |
