-- Smooth Trail script by ffoxD.
-- Reusable, use with credit.
local function SmoothTrail(mo, trailmo, freq)
    -- Real Z momentum thingy plus leveltime checks.
    -- You can replace all this with mo.momz+mo.pmomz but that stays at 0 when on slopes and on ground.
    if not mo.prevz or not mo.prevleveltime or (mo.prevleveltime ~= leveltime - 1) then
       mo.prevz = mo.z
    end
    local rmomz = mo.z - mo.prevz
    mo.prevz = mo.z
    mo.prevleveltime = leveltime
    -- Handy local variables.
    local mospeed = R_PointToDist2(0, 0, R_PointToDist2(0, 0, mo.momx, mo.momy), rmomz)
    local dist = (mospeed/freq)
    -- The loop, repeats until it spawns all the thok objects.
    for i = dist, 1, -1 do
        local spawnedmo = P_SpawnMobjFromMobj(mo, (mo.momx/dist)*i, (mo.momy/dist)*i, (rmomz/dist)*i, trailmo)
        spawnedmo.color = mo.color
    end
end
-- Usage example.
addHook("PlayerThink", function(player)
    player.spinitem = 0
    if player.pflags & PF_SPINNING then
        if skins[player.mo.skin].spinitem == -1 then
            SmoothTrail(player.mo, MT_THOK, 2*FRACUNIT)
        else
            SmoothTrail(player.mo, skins[player.mo.skin].spinitem, 2*FRACUNIT)
        end
    end
end)