OpenGL.GL.SGIX.fog_offset
OpenGL extension SGIX.fog_offset
This module customises the behaviour of the
OpenGL.raw.GL.SGIX.fog_offset to provide a more
Python-friendly API
Overview (from the spec)
This extension allows fragments to look brighter in a foggy
environment, by biasing the fragment eye-coordinate distance prior
to fog computation. A reference point in eye space (rx ry rz) and an offset
amount toward the viewpoint (f_o) are specified. When fog offset is
enabled, the offset amount will be subtracted from the fragment
distance, making objects appear less foggy.
If fog computation is done in screen-space coordinates under
perspective projection, the reference point is used in adjusting the
fog offset to be correct for fragments whose depth is close to that
point. The reference point should be redefined when it becomes too
far away from the primitives being drawn. Under orthographic
projection, or if fog computation is done in eye-space coordinates,
the reference point is ignored.
The official definition of this extension is available here:
http://www.opengl.org/registry/specs/SGIX/fog_offset.txt
Functions
Constants
GL_FOG_OFFSET_SGIX (33176)
GL_FOG_OFFSET_VALUE_SGIX (33177)