slope issues

physics

• Objects that aren't players are really bad at moving up and down slopes. (P_ZMovement runs the check and SlopeLaunch at the start of the function, while P_PlayerZMovement runs it later on. This may be why.)
• Ceiling (floor in reverse gravity) bouncing for non-player objects doesn't account for slopes. Needs fixed to.
• Fire trails on slopes don't work properly. Don't spawn going uphill, spawn but don't hurt going downhill.
• P_ButteredSlope doesn't get the object's actual gravity. Fix it. (Make a function to get an object's gravity if we don't already have one??)
• (lllloooowwww priority, feature request) Slide momentum up a wall from a steep enough slope so that quarter-pipes can at least slightly make physical sense. It would work like a slope launch and not actually stick the player to the wall.

rendering

• FOF planes don't layer properly when slopes are involved. Probably a simple check that needs tweaked.
• FOF planes also don't light properly. Similar issue, I believe.
• Sprites occasionally appear through walls that are near slopes. I bet I just misspelled something in the clipping code or some shit.
• Slope planes render with wrong height values when visportals are visible on-screen. (Compute and store relative viewx/y/z/angle when creating the visplane?)
• (low priority) Sloped FOFs with midtextures that have holes in them are completely broken. Texture alignment does not skew, but FOF holes do. Going to be a difficult fix.

ogl rendering (need to work with chee on)

• Midtextures + slopes == bugs.
• Sloped light blocks aren't properly rendered and do not affect sprites properly.

other

• Add the new height-related functions and slope structs and eeeeverything else to Lua metatables so that modders can access them.