http://bugs.winehq.org/show_bug.cgi?id=12641
--- Comment #3 from Markus Amsler markus.amsler@oribi.org 2008-10-17 16:02:07 --- I'm not sure anymore if this is a bug.
copied from ARB_vertex_program specification:
Dependencies on EXT_fog_coord
If EXT_fog_coord is not supported, references to fog coordinates should be removed from Table X.1, and the description of ArrayElement in section 2.8. The line "fogcoord" should be removed from the <vtxAttribItem> grammar rule, and "vertex.fogcoord" should be removed from Table X.2. Also, the use of FOG_COORDINATE_SOURCE_EXT in section 3.10 should be removed.
Even if EXT_fog_coord is not supported, the fog coordinate output (result.fogcoord) still operates as specified. When in vertex program mode, there are no well-defined eye coordinates that could be used for fog. This means that the functionality of EXT_fog_coord is required to implement ARB_vertex_program even if the EXT_fog_coord extension itself is not supported.
For me this looks like paragraph 1(vertex.fogcoord not supported) contradicts paragraph 2 (EXT_fog_coord is required to implement ARB_vertex_program).