-Minor code cleanup for the BSP node bounding-box check.

git-svn-id: http://odamex.net/svn/root/branches/persdiv@3678 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Fix some incorrect usage of the clamp macro. I have no idea what I was thinking...
-Fixes a few occasional integer overflows when calculating wall heights.

git-svn-id: http://odamex.net/svn/root/branches/persdiv@3679 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Create an overloaded version of R_PointOnSide that takes the coordinates of a line's endpoints.
-Simplify R_PointOnSide with a node_t* parameter and R_PointOnSegSide by calling this new version of R_PointOnSide.
-Use R_PointOnSide in R_ClipLine.

git-svn-id: http://odamex.net/svn/root/branches/persdiv@3680 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Reuse R_ClipLine to determine if the BSP node bounding-box is in the viewing window. Both diagonals of the box are passed to R_ClipLine and if they aren't entirely clipped, some portion of the box is visible.

git-svn-id: http://odamex.net/svn/root/branches/persdiv@3681 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Add a parameter to R_ClipLine that specifies the minimum distance from the viewer for clipping. 
-R_AddLine clips anything closer than NEARCLIP while R_CheckBBox clips at 0.

git-svn-id: http://odamex.net/svn/root/branches/persdiv@3682 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Add a check to determine if a masked seg is entirely above or below the viewing screen in R_RenderMaskedSeg. Remove the check in R_BlastMaskedColumn. This should be a more efficent way of preventing overflows when really close to offscreen masked segs.

git-svn-id: http://odamex.net/svn/root/branches/persdiv@3683 b0bcef46-2027-0410-bd56-ab726e9a1d04
-Add masktop and maskbottom arrays to keep track of the projected screen coordinates of the top and bottom of masked midtextures.
-Use masktop and maskbottom to determine if a masked midtexture column is visible (improved approach over r3683).
-Add macro FIXED2INT to convert fixed_t values to ints using rounding instead of truncation.
-Move FIXED2FLOAT, FLOAT2FIXED macros to m_fixed.h
-A bit of r_segs.cpp cleanup

git-svn-id: http://odamex.net/svn/root/branches/persdiv@3684 b0bcef46-2027-0410-bd56-ab726e9a1d04
Merge remote-tracking branch 'persdiv' into 32bpp-persdiv

Conflicts:
	common/r_main.h
Updated build script to be branch-aware.