-R_DrawColumnRange now takes a parameter for an object that generates the u texturemapping coordinates for each screen column and the vertical scaling for each column.
-drawseg_t now stores a pointer to the appropriate Texture.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4252 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Let the seg texture mapping object handle tiling textures horizontally instead of R_DrawColumnRange.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4253 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Properly mask two-sided midtextures.
-Refactor the seg lighting code.
-Remove maskedmidcols and midposts from drawseg_t, as well as texture.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4254 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Create a texture mapping object for sky rendering for use with R_DrawColumnRange.
-Limit several gloabl variables to static scope in r_sky.cpp.

git-svn-id: http://odamex.net/svn/root/branches/texmanager@4255 b0bcef46-2027-0410-bd56-ab726e9a1d04