OpenGL extension SGIS.texture_edge_clamp
This module customises the behaviour of the
OpenGL.raw.GL.SGIS.texture_edge_clamp to provide a more
Overview (from the spec)
The base OpenGL provides clamping such that the texture coordinates are
limited to exactly the range [0,1]. When a texture coordinate is
clamped using this algorithm, the texture sampling filter straddles the
edge of the texture image, taking 1/2 its sample values from within the
texture image, and the other 1/2 from the texture border. It is
sometimes desirable to clamp a texture without requiring a border, and
without using the constant border color.
This extension defines a new texture clamping algorithm.
CLAMP_TO_EDGE_SGIS clamps texture coordinates at all mipmap levels such
that the texture filter never samples a border texel. When used with a
NEAREST or a LINEAR filter, the color returned when clamping is derived
only from texels at the edge of the texture image. When used with
FILTER4 filters, the filter operations of CLAMP_TO_EDGE_SGIS are defined
but don't result in a nice clamp-to-edge color.
CLAMP_TO_EDGE_SGIS is supported by 1, 2, and 3-dimensional textures
The official definition of this extension is available here:
|EXTENSION_NAME = 'GL_SGIS_texture_edge_clamp'|
GL_CLAMP_TO_EDGE_SGIS = GL_CLAMP_TO_EDGE_SGIS
__file__ = '/home/mcfletch/pylive/OpenGL/GL/SGIS/texture_edge_clamp.pyc'
__name__ = 'OpenGL.GL.SGIS.texture_edge_clamp'
__package__ = 'OpenGL.GL.SGIS'