TubeSnapper.txt

--@name TubeSnapper
--@author Sparky
--@server

local function isTube(e)
    return string.match(e:getModel(), "models/hunter/tubes/tube")
end
local function isBend(e)
    return e:getModel() == "models/hunter/tubes/tubebend4x4x90.mdl"
end
local function getM(e1, e2)
    local m1, m2
    if isBend(e1) then
        m1 = e1:getMatrix()
        m1:rotate(Angle(0,0,-90))
    else
        m1 = e1:getMatrix()
    end
    m2 = e2:getMatrix()
    return m1, m2
end

local function angleDiff(axis, vec1, vec2)
    local D = math.asin(math.clamp(axis.x*(vec1.y*vec2.z - vec1.z*vec2.y) + axis.y*(vec1.z*vec2.x - vec1.x*vec2.z) + axis.z*(vec1.x*vec2.y - vec1.y*vec2.x),-1,1))
    if vec1:dot(vec2)>0 then
        return D
    else
        if D>0 then return math.pi-D else return -math.pi-D end
    end
end

local tubeEnd = chip():isWeldedTo()

local collide, collide2
local function nextTube(e)
    e:getPhysicsObject():enableMotion(false)

    local m1, m2 = getM(tubeEnd, e)
    local dir1, dir2 = m1:getUp(), m2:getUp()
    local axis, mag

    axis = dir2:cross(dir1):getNormalized()
    if axis[1]~=axis[1] then return end
    mag = math.acos(math.clamp(dir2:dot(dir1), -1, 1))

    local rot = Matrix()
    rot:setAxisAngle(axis, mag)
    m2 = rot * m2

    mag = angleDiff(dir1, m1:getForward(), m2:getForward())
    local snap = math.pi/8
    axis = dir1
    mag = math.round(mag/snap)*snap - mag
    
    rot = Matrix()
    rot:setAxisAngle(axis, mag)
    m2 = rot * m2

    e:setAngles(m2:getAngles())
    
    local pos1, pos2
    if isBend(tubeEnd) then
        pos1 = tubeEnd:localToWorld(Vector(0.007, 94.893, -0.011))
    else
        local mins, maxs = tubeEnd:getPhysicsObject():getAABB()
        pos1 = tubeEnd:localToWorld(Vector(0,0,maxs[3]))
    end
    if isBend(e) then
        pos2 = e:localToWorld(Vector(0.001, -0.015, -94.903))
    else
        local mins, maxs = e:getPhysicsObject():getAABB()
        pos2 = e:localToWorld(Vector(0,0,mins[3]))
    end
    e:setPos(e:getPos() + (pos1 - pos2))
    
    tubeEnd:removeCollisionListener()
    tubeEnd = e
    tubeEnd:addCollisionListener(collide)
end

local nextcollide = 0
function collide(t)
    if timer.curtime()<nextcollide then return end
    nextcollide = timer.curtime()+0.1
    local e = t.HitEntity
    if isTube(e) or isBend(e) then
        nextTube(e)
    end
end

tubeEnd:addCollisionListener(collide)
hook.add("remove","",function()
    tubeEnd:removeCollisionListener()
end)