Not convinced that the small speed benefit from P_AproxDistance is worth the "aproximate"[sic] results it gives. Let's instead try a define to replace it with FixedHypot. In Lua, the function gives a deprecated warning.
Inspired by the hyperwall fix for vanilla, except for everything. From little testing, actively improves waypoint checks, bumping, speed checks, wall collisions, Jawz targetting, Lightning Shield attacks, so on.
The only way I see this as a potential downgrade is A_Look (and related functions) getting slower, which are barely used in Kart.
This should fix the janky falling off steep slopes and let you cling to them.
Because when falling off a sector the edge of the player must not intersect
the edge of the higher sector, it is trickier than step up. The height
difference at the line must be stored to be useful.
This is for slopes. When moving across a slope the height changes. Therefore
compare the height at the edge where slopes meet so only a wall will block the
player, and not a very steep slope.
* If you collide with a line belonging to a polyobject, you should NEVER have to care about any FOFs that might be present in either sector of the linedef. This could lead to colliding with ghostly FOFs that aren't actually there or something dumb, if someone decided to give either of the polyobject's control sectors FOFs for some reason. We don't want that, obviously.
* Polyobjects without POF_CLIPPLANE apparently are supposed to have a top and bottom "physical" height of value INT32_MAX and _MIN respectively, according to P_CheckPosition ...let's be consistent with this.
* Finally, there is no more need for that back = front nonsense hack anymore with my changes made.
* Effect 3 (Peg Midtexture) is now accounted for properly, flipping the collision box position to match the actual rendered position of the midtexture
* Fixed incorrect application of y-offsets for non-lower unpegged midtextures collision boxes; +ve always goes up, -ve always goes down!
* Effect 4 now doesn't make midtextures solid for polyobjects at all - this "conflicted" with First Line having both Effect 4 (visible planes) and Effect 3 (intangible) simultaneously, where we kind of expect the first line's wall to not be made solid. This may be less of a problem in future SRB2 versions, but for now solid midtextures for polyobjects are disabled.
. tmthing can be NULL if called from PTR_SlideTraverse, so we should use slidemo instead
This fixes a crash that occurs in yet ANOTHER SUGOI map, involving bouncy walls next to sloped floors/ceilings
