The bad code was taken from the 2005 floating point rewrite that, by comparing the value with '> -EQUAL_EPSILON', returned 1 for any value close to 0 (as 'on the line') so it was mistakenly reported as 'behind the line'.
This required some changes to the Trace function because it turned out that the original was incapable of collecting the required information:
* actors are now also linked into blockmap blocks on both sides if they occupy the boundary of a sector portal.
* Trace will no longer set up parallel traces in all parts connected with sector portal, but only use one trace and relocate that on the actual boundary.
Only things left here are accesses to AActor::ceilingz and radius in A_PainShootSkull, plus scaleX and scaleY in the ScriptedMarine sprite setting code.
Most is still using wrapper functions around the fixed point versions.
- converted the P_TranslatePortal* functions to use floating point trigonometry. The combination of R_PointToAngle and finesine even created discrepancies with perfectly parallel portals which is just not acceptable.
- added a function to FPathTraverse to relocate the trace and restart from the new position.
- made P_UseLines portal aware. Traversal through line portals is complete (all types, even teleporters), whether sector portals need better treatment remains to be seen - at the moment it only checks the range at the player's vertical center.
* Arch-Vile resurrection
* Boom point pushers (due to complete lack of z-handling only for line portals.)
* A_RadiusGive
These also require a more thorough collection of portal groups than simple position checks.
- made some minor changes to FPathTraverse so that the Add*Intercepts methods can be virtually overridden.
- removed the PortalTracer class because in its existing form it was too costly. Replaced with a P_GetOffsetPosition function that does the minimum required work to get to the translated destination and that's better suited for being called from the Vec*Offset methods. Other use cases will require some changes to FPathTraverse anyway, or some wrapping class like the FMultiBlock iterators.
* removed all code for dealing with z-displacing portals in the iterator loops. This would cause too many problems so I decided to scrap any provisions for allowing interactive portals with z-displacement. They will remain restricted to pure teleporter portals.
* changed spechit to carry a position along with the special line. If something is activated through an interactive portal this is needed to calculate movement.
* pass the abovementioned position to CheckForPushSpecial.
* collect touched portal lines in a second array analogous to spechit.
* use FMultiBlockThingsIterator in P_TestMobjZ.
(This is just a safety commit before doing some more extensive behind-the-scenes refactoring.)
Notable changes here:
* use the same logic for determining whether a 3D floor is 'below' or 'above' the actor as all the other functions.
* removed the broken code which tried to detect whether an actor was touching a steep slope. Better use P_LineOpening to find the correct planes and store the results.
* improved detection whether the slopes on both sides of a plane are identical, using the same data as for steep slope detection.
- some consolidation in p_map.cpp. PIT_CheckLine and PIT_FindFloorCeiling had quite a bit of redundancy which has been merged.
- čontinued work on FMultiBlockLinesIterator. It's still not completely finished.
This was to resolve some circular dependencies with the portal code.
The most notable changees:
* FTextureID was moved from textures.h to doomtype.h because it is frequently needed in files that don't want to do anything with actual textures.
* split off the parts from p_maputl into a separate header.
* consolidated all blockmap related data into p_blockmap.h
* split off the polyobject parts into po_man.h
