Previously we had a single culling frustum based on the main camera, and
any object outside the frustum would never get rendered, even if it
should actually contribute to shadows or reflections/refractions. This
caused ugly pop-in effects in the shadows and reflections while
scrolling.
Extend the renderer to support multiple cull groups, each with a
separate frustum and with separate lists of submitted objects, so that
shadows and reflections will render the correctly culled sets of
objects.
Update the shadow map generation to compute the (hopefully) correct
bounds and matrices for this new scheme.
Include terrain patches in the shadow bounds, so hills can cast shadows
correctly.
Remove the code that tried to render objects slightly outside the camera
frustum in order to reduce the pop-in effect, since that was a
workaround for the lack of a proper fix.
Remove the model/patch filtering code, which was used to cull objects
that were in the normal camera frustum but should be excluded from
reflections/refractions, since that's redundant now too.
Inline DistanceToPlane to save a few hundred usecs per frame inside
CCmpUnitRenderer::RenderSubmit.
Fixes#504, #579.
This was SVN commit r15445.
