Placement Module Script

local INTERPOLATION = true -- whether placement smoothing is enabled
local INTERPOLATION_DAMP = .21 -- how fast smoothing is, make it a value (0, 1]
local ROTATION_SPEED = .2 -- rotation tween speed in seconds

local COLLISION_COLOR3 = Color3.fromRGB(255,0,0)--BrickColor.Red().Color -- color of the hitbox when object collides
local COLLISION_TRANSPARENCY = .6 -- transparency of the hitbox when object collides

local NORMAL_COLOR3 = BrickColor.new().Color -- color of the hitbox
local NORMAL_TRANSPARENCY = .6 -- transparency of the hitbox

local LOAD_COLOR3 = Color3.fromRGB(226, 155, 64) -- color of the hitbox when loading
local LOAD_TRANSPARENCY = .6 -- transparency of the hitbox when loading

local GRID_TEXTURE = "rbxassetid://13786085" -- texture of the grid space, set to nil if you don't want a visible grid

local OVERRIDE_CONTROLS = false -- whether click to place and r to rotate are enabled
local INPUT_PRIORITY = 9 -- input priority of default controls
local TOUCH_RANGE = 30 -- range of mobile placement

local PLACEMENT_COOLDOWN = .45 -- how quickly the user can place


--[[
    DO NOT EDIT PAST THESE LINES UNLESS YOU KNOW WHAT YOU'RE DOING
--]]

local module = {}

local player = game.Players.LocalPlayer
local mouse = player:GetMouse()
local runService = game:GetService("RunService")
local touch = game:GetService("UserInputService").TouchEnabled

local currentPlane
local currentBase

local renderConnection = nil

local cx, cy, cz, cr = 0, 0, 0, 0
local currentObjects = {}
local currentEvent
local currentTexture
local currentPosition = Vector3.new(0, 0, 0)
local ax, az

local currentExtentsX
local currentExtentsZ
local currentYAxis
local currentXAxis
local currentZAxis
local currentAxis

local ox, oy, oz -- do
local dxx, dxy, dxz
local dzx, dzy, dzz

local min = math.min
local max = math.max
local abs = math.abs

local springVelocity = Vector3.new(0, 0, 0)
local springPosition = Vector3.new(0, 0, 0)
local tweenGoalRotation = 0 -- springs arent worth effort for rotation
local tweenStartRotation = 0
local tweenCurrentRotation = 0
local tweenAlpha = 1

local lastRenderCycle = tick()
local lastPlacement = tick()

local function round(n, to)
    return n % to ~= 0 and (n % to) > to/2 and (n + to - (n % to)) or (n - (n % to))
end

local function project(px, py, pz)
    px, py, pz = px - ox, py - oy, pz - oz

    return px * dxx + py * dxy + pz * dxz, px * dzx + py * dzy + pz * dzz
end

local function translate(px, pz, r)
    if (r == 0) then
        return px, pz
    elseif (r == 1) then
        return -pz, px
    elseif (r == 2) then
        return -px, -pz
    elseif (r == 3) then
        return pz, -px
    end

--  or for all angles
--  r = r * math.pi/2
--  return math.cos(r) * px - math.sin(r) * pz,  math.sin(r) * px + math.cos(r) * pz
end

local function angleLerp(a, b, d) -- to avoid angle jump
    local x1, y1 = math.cos(a), math.sin(a)
    local x2, y2 = math.cos(b), math.sin(b)

    return math.atan2(y1 + (y2 - y1) * d, x1 + (x2 - x1) * d)
end

local function calculateExtents(part, cf)
    local cf = cf or part.CFrame

    local edgeA = cf * CFrame.new(-part.Size.X/2, 0, 0)
    local edgeB = cf * CFrame.new(part.Size.X/2, 0, 0)
    local edgeC = cf * CFrame.new(0, 0, part.Size.Z/2)
    local edgeD = cf * CFrame.new(0, 0, -part.Size.Z/2)

    local edgeAx, edgeAz = project(edgeA.X, edgeA.Y, edgeA.Z)
    local edgeBx, edgeBz = project(edgeB.X, edgeB.Y, edgeB.Z)
    local edgeCx, edgeCz = project(edgeC.X, edgeC.Y, edgeC.Z)
    local edgeDx, edgeDz = project(edgeD.X, edgeD.Y, edgeD.Z)

    local extentsX = max(edgeAx, edgeBx, edgeCx, edgeDx) - min(edgeAx, edgeBx, edgeCx, edgeDx)
    local extentsZ = max(edgeAz, edgeBz, edgeCz, edgeDz) - min(edgeAz, edgeBz, edgeCz, edgeDz)

    return round(extentsX, currentPlane.grid), round(extentsZ, currentPlane.grid)
end

local states = {
    neutral = 1;
    collision = 2;
    loading = 3;
}

module.states = states

local function setState(object, state, downward)
    if (object.state and (object.state == state or (object.state > state and not downward))) then
        return
    end

    object.state = state

    if (state == 1) then
        if (NORMAL_COLOR3) then
            object.model.PrimaryPart.Color = NORMAL_COLOR3
        end
        if (NORMAL_TRANSPARENCY) then
            object.model.PrimaryPart.Transparency = NORMAL_TRANSPARENCY
        end
    elseif (state == 2) then
        if (COLLISION_COLOR3) then
            object.model.PrimaryPart.Color = COLLISION_COLOR3
        end
        if (COLLISION_TRANSPARENCY) then
            object.model.PrimaryPart.Transparency = COLLISION_TRANSPARENCY
        end
    elseif (state == 3) then
        if (LOAD_COLOR3) then
            object.model.PrimaryPart.Color = LOAD_COLOR3
        end
        if (LOAD_TRANSPARENCY) then
            object.model.PrimaryPart.Transparency = LOAD_TRANSPARENCY
        end
    end

    currentPlane.stateEvent:Fire(object.model, state)
end

--[[
    status
    model
    px, pz, r
    sx, sz
--]]

local function floatEqual(a, b)
    return (math.abs(a - b) < .01)
end

local function floatGreater(a, b)
    return (a - b) > .01
end

local function floatLesser(a, b)
    return (b - a) > .01
end

local function obstacleCollision()
    local px, pz = cx, cz

    local collision = false

    for _, model in pairs(currentPlane.obstacles:GetChildren()) do
        if (model.PrimaryPart) then

            local extentsX1, extentsZ1 = calculateExtents(model.PrimaryPart)
            local x1, z1 = project(model.PrimaryPart.Position.X, model.PrimaryPart.Position.Y, model.PrimaryPart.Position.Z)

            for i = 1, #currentObjects do
                local object = currentObjects[i]

                if (not object.collision) then
                    local r = (object.r + cr) % 4

                    local x0, z0 = translate(object.px, -object.pz, cr)
                    x0 = x0 + px
                    z0 = z0 + pz

                    local extentsX0, extentsZ0

                    if (r == 1 or r == 3) then
                        extentsX0, extentsZ0 = object.sz, object.sx
                    else
                        extentsX0, extentsZ0 = object.sx, object.sz
                    end

                    if (floatLesser(x0 - extentsX0/2, x1 + extentsX1/2) and floatGreater(x0 + extentsX0/2, x1 - extentsX1/2) and floatLesser(z0 - extentsZ0/2, z1 + extentsZ1/2) and floatGreater(z0 + extentsZ0/2, z1 - extentsZ1/2)) then
                        collision = true
                        object.collision = true
                        setState(object, states.collision)
                    end
                end
            end
        end
    end

    for i = 1, #currentObjects do
        local object = currentObjects[i]

        if (not object.collision and object.state == states.collision) then
            setState(object, states.neutral, true)
        else
            object.collision = nil
        end
    end

    return not collision
end

local function inputCapture() -- converts user inputs to 3d position, built in mobile compatibility
    local position

    if (touch) then
        local camera = workspace.CurrentCamera
        local range = TOUCH_RANGE * (camera.Focus.p - camera.CFrame.p).magnitude/5

        position = camera.Focus.p + camera.CFrame.lookVector * (camera.CoordinateFrame.lookVector.Y/2 + .5) * range
    else
        local hit, p = workspace:FindPartOnRayWithWhitelist(Ray.new(mouse.UnitRay.Origin, mouse.UnitRay.Direction * 999), {currentPlane.base})

        if (hit) then
            position = p
        end
    end

    return position, cr
end

local resting = false

local function calc(position, rotation, force)
    if (not currentPlane or currentPlane.loading) then
        return
    end

    force = force == true

    local ux, uz

    if (position) then
        ux, uz = project(position.X, position.Y, position.Z)
    else
        ux, uz = ax or 0, az or 0
    end

    local nr = rotation or cr

    local nx = round(ux, currentPlane.grid)
    local nz = round(uz, currentPlane.grid)

    local extentsX, extentsZ = translate(currentExtentsX, currentExtentsZ, nr)
    extentsX = abs(extentsX)
    extentsZ = abs(extentsZ)

    if (floatEqual(extentsX/2 % currentPlane.grid, 0)) then
        nx = nx + currentPlane.grid/2
    end

    if (floatEqual(extentsZ/2 % currentPlane.grid, 0)) then
        nz = nz + currentPlane.grid/2
    end

    nx = nx + currentPlane.offsetX
    nz = nz + currentPlane.offsetZ

    local borderX = currentPlane.size.X/2
    local borderZ = currentPlane.size.Z/2

    ax = ux
    az = uz

    if (nx + extentsX/2 > borderX) then
        nx = nx - (nx + extentsX/2 - borderX)
    elseif (nx - extentsX/2 < -borderX) then
        nx = nx - (nx - extentsX/2 + borderX)
    end

    if (nz + extentsZ/2 > borderZ) then
        nz = nz - (nz + extentsZ/2 - borderZ)
    elseif (nz - extentsZ/2 < -borderZ) then
        nz = nz - (nz - extentsZ/2 + borderZ)
    end

    if (force or nx ~= cx or nz ~= cz or cr ~= nr) then
        cx, cz, cr = nx, nz, nr
        resting = false
        currentPosition = (Vector3.new(ox, oy, oz) + currentXAxis * nx + currentZAxis * nz)
        obstacleCollision()
    end
end

local function render()
    if (resting) then
        return
    end

    if (INTERPOLATION) then
        local delta = 1/60

        springVelocity = (springVelocity + (currentPosition - springPosition)) * INTERPOLATION_DAMP * 60 * delta
        springPosition = springPosition + springVelocity

        local extentsX, extentsZ = translate(currentExtentsX, currentExtentsZ, cr)

        local vx, vz = 9 * springVelocity:Dot(currentXAxis)/abs(extentsX), 9 * springVelocity:Dot(currentZAxis)/abs(extentsZ)
        local r

        if (not floatEqual(tweenGoalRotation, cr * math.pi/2)) then
            tweenStartRotation = tweenCurrentRotation
            tweenGoalRotation = cr * math.pi/2
            tweenAlpha = 0
        end

        if (tweenAlpha < 1) then
            tweenAlpha = min(1, tweenAlpha + delta/ROTATION_SPEED)
            tweenCurrentRotation = angleLerp(tweenStartRotation, tweenGoalRotation, 1 - (1 - tweenAlpha)^2)
            r = tweenCurrentRotation
        else
            r = cr * math.pi/2
        end


        local effectAngle = CFrame.Angles(math.sqrt(math.abs(vz/100)) * math.sign(vz), 0, math.sqrt(math.abs(vx/100)) * math.sign(vx))

        local rotationCFrame = currentAxis * effectAngle * CFrame.Angles(0, r, 0)
        local centerCFrame = rotationCFrame + springPosition

        for i = 1, #currentObjects do
            local object = currentObjects[i]

            local x, z = object.px, object.pz

            object.model:SetPrimaryPartCFrame(centerCFrame * CFrame.Angles(0, object.r * math.pi/2, 0) + rotationCFrame * Vector3.new(x, object.sy/2, z))
        end

        if (springVelocity.magnitude < .01 and tweenAlpha >= 1) then
            resting = true
        end
    else
        local rotationCFrame = currentAxis * CFrame.Angles(0, cr * math.pi/2, 0)

        for i = 1, #currentObjects do
            local object = currentObjects[i]
            local x, z = object.px, object.pz

            object.model:SetPrimaryPartCFrame(rotationCFrame * CFrame.Angles(0, object.r * math.pi/2, 0) + rotationCFrame * Vector3.new(x, object.sy/2, z) + currentPosition)
        end

        resting = true
    end
end

local function run(display)
    local position, rotation = inputCapture()

    if (position or rotation) then
        calc(position, rotation)
        if (display) then
            render()
        end
    end
end

local function place()
    if (currentPlane and (obstacleCollision()) and (tick() - lastPlacement) >= PLACEMENT_COOLDOWN and not currentPlane.loading) then
        lastPlacement = tick()

        local modelCFrames = {}

        for i = 1, #currentObjects do
            local object = currentObjects[i]
            modelCFrames[i] = currentAxis * CFrame.Angles(0, (object.r + cr) * math.pi/2, 0) +  (currentAxis * CFrame.Angles(0, cr * math.pi/2, 0)) * Vector3.new(object.px, object.sy/2, object.pz) + currentPosition
        end

        currentEvent:Fire(modelCFrames)
    end
end

local function rotate()
    calc(nil, (cr + 1) % 4)
    render()
end

local function inputRotate(_, userInputState, inputObject)
    if (currentPlane and userInputState == Enum.UserInputState.End) then
        rotate()
    end
end

local function inputPlace(_, userInputState, inputObject)
    if (currentPlane and userInputState == Enum.UserInputState.End) then
        place()
    end
end

local function bindInputs()
    if (not OVERRIDE_CONTROLS) then
        game:GetService("ContextActionService"):BindActionAtPriority("PlacementModule_Rotate", inputRotate, false, INPUT_PRIORITY, Enum.KeyCode.R)
        game:GetService("ContextActionService"):BindActionAtPriority("PlacementModule_Place", inputPlace, false, INPUT_PRIORITY, Enum.UserInputType.MouseButton1)
    end
end

local function unbindInputs()
    if (not OVERRIDE_CONTROLS) then
        game:GetService("ContextActionService"):UnbindAction("PlacementModule_Rotate")
        game:GetService("ContextActionService"):UnbindAction("PlacementModule_Place")
    end
end

local function enablePlacement(plane, models, prealigned)
    if (plane == currentPlane) then
        return
    elseif (currentPlane) then
        currentPlane:disable()
    end

    if (type(models) ~= "table") then
        models = {models}
    end

    lastRenderCycle = tick()

    currentPlane = plane
    currentBase = plane.base

    local planePosition = currentBase.CFrame * Vector3.new(0, currentBase.Size.Y/2, 0)

    resting = false
    ox, oy, oz = planePosition.X, planePosition.Y, planePosition.Z
    currentXAxis = currentBase.CFrame.rightVector
    currentYAxis = currentBase.CFrame.upVector
    currentZAxis = currentBase.CFrame.lookVector
    currentAxis = CFrame.new(0, 0, 0, currentXAxis.X, currentYAxis.X, -currentZAxis.X, currentXAxis.Y, currentYAxis.Y, -currentZAxis.Y, currentXAxis.Z, currentYAxis.Z, -currentZAxis.Z)
    currentObjects = {}
    dxx, dxy, dxz = currentXAxis.X, currentXAxis.Y, currentXAxis.Z
    dzx, dzy, dzz = currentZAxis.X, currentZAxis.Y, currentZAxis.Z
    cx, cy, cz, cr = 0, 0, 0, 0

    springVelocity = Vector3.new(0, 0, 0)
    springPosition = Vector3.new(0, 0, 0)

    tweenAlpha = 0
    tweenCurrentRotation = 0
    tweenGoalRotation = 0
    tweenStartRotation = 0

    local position, _ = inputCapture()

    if (not position) then
        position = planePosition
    end

    springPosition = position

    do
        local extentsXMin, extentsXMax = 10e10, -10e10
        local extentsZMin, extentsZMax = 10e10, -10e10

        for i = 1, #models do
            local model = models[i]
            local object = {}
            object.model = model

            local lookVector = object.model.PrimaryPart.CFrame.lookVector
            local theta
            local px, pz

            if (prealigned) then
                local position = object.model.PrimaryPart.CFrame * Vector3.new(0, -object.model.PrimaryPart.Size.Y/2 , 0)
                px, pz = project(position.X, position.Y, position.Z)

                theta = math.acos(math.clamp(lookVector:Dot(currentZAxis), -1, 1))
                local cross = lookVector:Cross(currentZAxis)

                if (cross:Dot(currentYAxis) > 0) then
                    theta = -theta
                end

            else
                px, pz = object.model.PrimaryPart.Position.X, object.model.PrimaryPart.Position.Z
                theta = math.atan2(lookVector.X, lookVector.Z)
            end

            local x, z = model.PrimaryPart.Size.X, model.PrimaryPart.Size.Z

            object.r = round((theta % (2 * math.pi))/(math.pi/2), 1)

            if (object.r == 1 or object.r == 3) then
                x, z = z, x
            end

            local x1, x2 = px + x/2, px - x/2
            local z1, z2 = pz + z/2, pz - z/2

            if (x2 < extentsXMin) then
                extentsXMin = x2
            end
            if (x1 > extentsXMax) then
                extentsXMax = x1
            end

            if (z2 < extentsZMin) then
                extentsZMin = z2
            end
            if (z1 > extentsZMax) then
                extentsZMax = z1
            end


            model.PrimaryPart.Transparency = .5
            model.PrimaryPart.Anchored = true
            model.PrimaryPart.CanCollide = false

            setState(object, plane.loading and states.loading or states.neutral)

            currentObjects[i] = object
        end

        currentExtentsX, currentExtentsZ = round(extentsXMax - extentsXMin, currentPlane.grid), round(extentsZMax - extentsZMin, currentPlane.grid)

        for i = 1, #currentObjects do
            local object = currentObjects[i]
            local px, pz

            if (prealigned) then
                local position = object.model.PrimaryPart.CFrame * Vector3.new(0, -object.model.PrimaryPart.Size.Y/2, 0)
                px, pz = project(position.X, position.Y, position.Z)
            else
                px, pz = object.model.PrimaryPart.Position.X, object.model.PrimaryPart.Position.Z
            end

            object.px = px - (extentsXMin + extentsXMax)/2
            object.pz = (pz - (extentsZMin + extentsZMax)/2) * (prealigned and -1 or 1)

            object.sx, object.sy, object.sz = object.model.PrimaryPart.Size.X, object.model.PrimaryPart.Size.Y, object.model.PrimaryPart.Size.Z
        end
    end

    renderConnection = runService.RenderStepped:connect(run)
    module.currentPlane = currentPlane
    currentEvent = Instance.new("BindableEvent")

    if (GRID_TEXTURE) then
        currentTexture = Instance.new("Texture", currentPlane.base)
        currentTexture.Texture = GRID_TEXTURE
        currentTexture.Face = Enum.NormalId.Top
        currentTexture.StudsPerTileU = currentPlane.grid
        currentTexture.StudsPerTileV = currentPlane.grid
    end

    bindInputs()

    run(true)

    return currentEvent.Event
end

local function disablePlacement(plane)
    if (currentPlane) then
        renderConnection:disconnect()
        renderConnection = nil
        currentPlane = nil
        module.currentPlane = nil
        currentEvent:Destroy()
        currentEvent = nil

        if (currentTexture) then
            currentTexture:Destroy()
            currentTexture = nil
        end

        for i = 1, #currentObjects do
            local object = currentObjects[i]
            object.model = nil
            currentObjects[i] = nil
        end

        unbindInputs()
    end
end

local function setLoading(plane, isLoading)
    if (plane.loading == isLoading) then
        return
    end

    plane.loading = isLoading

    if (plane == currentPlane) then
        if (isLoading) then
            for i = 1, #currentObjects do
                setState(currentObjects[i], states.loading)
            end
        else
            for i = 1, #currentObjects do
                setState(currentObjects[i], states.neutral, true)
            end

            obstacleCollision()
        end
    end
end

module.new = function(base, obstacles, grid)
    local plane = {}
    plane.base = base
    plane.obstacles = obstacles
    plane.position = base.Position
    plane.size = base.Size

    if (math.floor(.5 + plane.size.X/grid) % 2 == 0) then
        plane.offsetX = -grid/2
    else
        plane.offsetX = 0
    end

    if (math.floor(.5 + plane.size.Z/grid) % 2 == 0) then
        plane.offsetZ = -grid/2
    else
        plane.offsetZ = 0
    end


    plane.stateEvent = Instance.new("BindableEvent")
    plane.stateChanged = plane.stateEvent.Event

    plane.grid = grid
    plane.enable = enablePlacement
    plane.disable = disablePlacement
    plane.rotate = rotate
    plane.place = place
    plane.setLoading = setLoading

    return plane
end

module.setLoading = setLoading
module.currentPlane = false

return module