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.
This will fail when a trace starts directly on a block boundary in which case x is a whole number. It should always use 'floor(x)+1' to ensure that the calculated point is at the right or upper edge of a block.
* we do not really need compatibility PointOnLineSide here. Unlike the movement code it'd only affect some extreme edge cases.
* removed the special case for very short traces. This was a result of the original and very imprecise PointOnLine functions. Since those no longer get used here and floating point precision is a lot higher there is no need for this kind of treatment.
* PointOnLine checks for the sides of an actor's bounding box don't need a full PointOnLineSide call, a simple coordinate comparison is fully sufficient, and this can easily be done in the existing switch/case block.
* typo in calculating end position from a trace vector
* must use floor to convert from floating point block coordinate to block index to account for running off the negative side of the blockmap. (Int cast always rounds toward zero which is wrong here.)
* bad calculation of sight checking slopes - they has the actor's z coordinate duplicated.
- fixed scaling of automap markers.
- Converted P_MovePlayer and all associated variables to floating point because this wasn't working well with a mixture between float and fixed.
Like the angle commit this has just been patched up to compile, the bulk of work is yet to be done.
Links through sector portals are not done because nearly all the checks can be performed without doing this so if it works without there's no need to add more processing time.
Will have to see if there's cases left where such a link is needed and if so, whether there's better options to do it.
For line portals such links are necessary to have proper collision detection with actors that are currently transitioning the portal.
- fixed: FMultiBlockLinesIterator initialized continueup twice but forgot continuedown.
- fixed: One of the debug messages in P_AimLineAttack was missing an if (aimdebug).
* when starting directly on a blockline the trace was offset by one map unit. Do this only for the internal block trace calculations but not for the variable that's being exposed to the outside because in rare situations that can create incorrect values.
* using startfrac could lead to an actor whose inside was right at that positon to be missed.
* when using startfrac the adjusted trace start was not used for all calculations, which could cause the trace to fail.
With these issues fixed, P_AimLineAttack can now successfully navigate line portals.
- 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.
It can easily happen that the lower sector has no lines below the checked area, in which case it would not set the dropoffz correctly. To prevent this, P_LineOpening must, when it checks the opening over a sector portal, actually calculate the dropoff to the lower portal itself by calling sector_t::NextLowestPointAt. It also means that FindRefPoint must calculate a proper reference point when one side of the line to be checked is part of a floor portal.
- added portal offsetting to all AproxDistance, AngleTo and Vec*To members of AActor.
- optimized displacement retrieval so that the most common case with no offset retrieves a constant null-vector which can be optimized away fully by the compiler.
- early out in P_GetOffsetPosition if there's no portal lines nearby, so that the common case can skip the traverser completely even on maps with line portals.
