SimpleCar.txt

--@name SimpleCar
--@author Sparky
--@shared
--@include libs/criticalpd.txt
--@include libs/xinput.txt


local brakepower = 1 -- Brake multiplier
local throttlepower = 500 -- Throttle multiplier
local maxAngSpeed = 3500 -- Max tire angular velocity
local minTurnRadius = 175.019 -- Minimum turn radius
local maxTurnAcceleration = 1000 -- 800 is 1G
local carForward = Vector(0,0,-1) -- Vector local to car body pointing forward
local carRight = Vector(0,-1,0) -- Vector local to car body pointing right
local hudMatrix = Matrix()

require("libs/xinput.txt")

if SERVER then

local criticalpd = require("libs/criticalpd.txt")
local wheel = class("wheel")
local steering = class("steering", wheel)
local car = class("car")

function wheel:initialize(car, ent)
    self.pd = criticalpd:new(ent, 0, 500)
    self.car = car
    self.ent = ent
    self.forward = self.pd.phys:worldToLocalVector(car.bodyPhys:localToWorldVector(car.right))
    self.radius = ent:obbMaxs()[1]
end

function wheel:simulate()
    self.pd:simulateAngForceCustomError(Vector(), self:calcSpeed()-self.pd.phys:localToWorldVector(self.ent:getAngleVelocity()))
end

function wheel:calcSpeed()
    local throttle = self.car.throttle
    local brake = self.car.brake
    local wheelvel = self.ent:getAngleVelocity():dot(self.forward)
    
    local speed = math.clamp((self.car.bodyrotvel - wheelvel)*brake*brakepower + wheelvel - throttle*throttlepower, -maxAngSpeed, maxAngSpeed)
    return self.pd.phys:localToWorldVector(self.forward) * speed
end

function steering:initialize(car, ent, forward)
    wheel.initialize(self, car, ent, forward)
end

function steering:simulate(turndir, sign)
    local phys = self.pd.phys
    local forward = phys:localToWorldVector(self.forward)
    
    local axis = forward:cross(turndir):getNormalized()
    local angleDeg = math.deg(math.acos(math.clamp(turndir:dot(forward), -1, 1)))
    
    self.pd:simulateAngForceCustomError(axis*angleDeg, self.car.bodyangvel+self:calcSpeed()-phys:localToWorldVector(self.ent:getAngleVelocity()))
end

function car:initialize(forward, right, body, chair, wheelfr, wheelfl, wheelbr, wheelbl)
    self.body = body
    self.joystickSteer = nil
    self.forward = forward
    self.right = right
    self.bodyPhys = body:getPhysicsObject()
    self.chair = chair
    self.wheelfr = steering:new(self, wheelfr)
    self.wheelfl = steering:new(self, wheelfl)
    self.wheelbr = wheel:new(self, wheelbr)
    self.wheelbl = wheel:new(self, wheelbl)
    self.turninv = 0
    self.throttle = 0
    self.brake = 1
end

function car:simulate()
    self.bodyvel = self.bodyPhys:worldToLocalVector(self.body:getVelocity()):dot(self.forward)
    local angvel = self.body:getAngleVelocity()
    self.bodyrotvel = angvel:dot(self.right)
    self.bodyangvel = self.bodyPhys:localToWorldVector(angvel)

    if self.driver then
        local w, a, s, d, turbo, brake = 
        self.driver:keyDown(IN_KEY.FORWARD), 
        self.driver:keyDown(IN_KEY.MOVELEFT), 
        self.driver:keyDown(IN_KEY.BACK), 
        self.driver:keyDown(IN_KEY.MOVERIGHT),
        self.driver:keyDown(IN_KEY.SPEED),
        self.driver:keyDown(IN_KEY.JUMP)
        
        local targetradiusinv = math.clamp(maxTurnAcceleration/self.bodyvel^2, 0, 1/minTurnRadius)
        if self.joystickSteer then
            self.turninv = self.joystickSteer*targetradiusinv
            self.throttle = self.joystickThrottle
            self.brake = 0
        else
            if a then
                self.turninv = self.turninv*0.9-targetradiusinv*0.1
            elseif d then
                self.turninv = self.turninv*0.9+targetradiusinv*0.1
            else
                self.turninv = self.turninv*0.5
            end
            self.throttle = (w and (turbo and 2 or 1)) or (s and (turbo and -2 or -1)) or 0
            self.brake = brake and 1 or 0
        end
    else
        self.throttle = 0
        self.brake = 1
        self.joystickSteer = nil
    end
    
    local right = self.bodyPhys:localToWorldVector(self.right)
    local turndirR, turndirL
    if math.abs(self.turninv)<0.000001 then
        turndirR = right
        turndirL = right
    else
        local wheelfrPos = self.wheelfr.ent:getMassCenterW()
        local wheelflPos = self.wheelfl.ent:getMassCenterW()
        local wheelbrPos = self.wheelbr.ent:getMassCenterW()
        local wheelblPos = self.wheelbl.ent:getMassCenterW()
        local pivot = (wheelblPos+wheelbrPos)/2
        local turn = pivot + right*(1/self.turninv)
        local turnSign = math.sign(self.turninv)
        turndirR = (turn - wheelfrPos):getNormalized()*turnSign
        turndirL = (turn - wheelflPos):getNormalized()*turnSign
    end
    
    self.wheelfr:simulate(turndirR)
    self.wheelfl:simulate(turndirL)
    self.wheelbr:simulate()
    self.wheelbl:simulate()
end

function car:setDriver(driver)
    self.driver = driver
end

local mycar
do
    local body = chip():isWeldedTo()
    local chair, chairdot = nil, -math.huge
    local wheelfr, wheelfrdot = nil, -math.huge 
    local wheelfl, wheelfldot = nil, -math.huge 
    local wheelbr, wheelbrdot = nil, -math.huge 
    local wheelbl, wheelbldot = nil, -math.huge 
    for _, v in ipairs(constraint.getTable(body)) do
        local ent = v.Ent1 == body and v.Ent2 or v.Ent1
        local pos = body:worldToLocal(ent:getMassCenterW())
        if ent:isVehicle() then
            local posdot = pos:dot(carForward)-pos:dot(carRight)
            if posdot > chairdot then
                chairdot = posdot
                chair = ent
            end
        elseif v.Type == "AdvBallsocket" or v.Type == "Axis" then
            local posdot
            posdot = pos:dot(carForward)+pos:dot(carRight)
            if posdot > wheelfrdot then
                wheelfrdot = posdot
                wheelfr = ent
            end
            posdot = pos:dot(carForward)-pos:dot(carRight)
            if posdot > wheelfldot then
                wheelfldot = posdot
                wheelfl = ent
            end
            posdot = -pos:dot(carForward)+pos:dot(carRight)
            if posdot > wheelbrdot then
                wheelbrdot = posdot
                wheelbr = ent
            end
            posdot = -pos:dot(carForward)-pos:dot(carRight)
            if posdot > wheelbldot then
                wheelbldot = posdot
                wheelbl = ent
            end
        end
    end
    if not body then error("Chip isn't welded to the car body!") end
    if not chair then error("No vehicle welded to car body!") end
    if not (wheelfr and wheelfl and wheelbr and wheelbl) then error("The car needs 4 wheels!") end
    mycar = car:new(carForward, carRight, body, chair, wheelfr, wheelfl, wheelbr, wheelbl)
end

hook.add("think","simulate",function()
    mycar:simulate()
end)

hook.add("playerenteredvehicle","",function(ply,veh)
    if mycar.chair == veh then
        mycar:setDriver(ply)
        xinput.setListeners(ply, "sThumbLX bRightTrigger bLeftTrigger", true)
    end
end)

hook.add("playerleavevehicle","",function(ply,veh)
    if mycar.chair == veh then
        mycar:setDriver(nil)
        xinput.setListeners(ply, "sThumbLX bRightTrigger bLeftTrigger", false)
    end
end)

hook.add("xinput","",function(ply, data)
    if mycar.driver == ply then
        mycar.joystickSteer = data.sThumbLX/32768
        mycar.joystickThrottle = data.bRightTrigger/255 - data.bLeftTrigger/255
    else
        xinput.setListeners(ply, "sThumbLX bRightTrigger bLeftTrigger", false)
    end
end)

hook.add("clientinitialized","",function(ply)
    net.start("car")
    net.writeEntity(mycar.body)
    net.send(ply)
end)

else -- CLIENT

local carent
net.receive("car",function()
    net.readEntity(function(ent) carent = ent end)
end)

local font = render.createFont("Roboto",32)
local font2 = render.createFont("Roboto",128)
local carvel = 0
hook.add("render","",function()
    if not (carent and carent:isValid()) then return end
    local forward = carent:localToWorld(carForward) - carent:getPos()
    carvel = carvel*0.95 + carent:getVelocity():dot(forward)*0.05*0.0568182
    local bearing = math.atan2(forward[1], forward[2])

    
    render.setFont(font2)
    render.drawText(256, 256, string.format("%03.0f", math.abs(carvel)), 1)
    render.setFont(font)
    render.drawText(380, 320, "mph", 1)
    local S1, S2
    if bearing < -math.pi/2 then
        bearing = bearing + math.pi
        S1, S2 = "W", "S"
    elseif bearing<0 then
        bearing = bearing + math.pi/2
        S1, S2 = "N", "W"
    elseif bearing<math.pi/2 then
        S1, S2 = "E", "N"
    else
        S1, S2 = "S", "E"
        bearing = bearing - math.pi/2
    end
    local compassMatrix = Matrix() compassMatrix:setTranslation(Vector(256, 512, 0))
    render.pushMatrix(compassMatrix)
    do
        local x = 100*math.cos(bearing)
        local y = -50*math.sin(bearing)
        render.drawText(x*1.2, y*1.2-20, S1, 1)
        local tx, ty = -y*0.05, x*0.05
        render.drawPoly({{x = -tx, y = -ty},{x = x, y = y},{x = tx, y = ty}})
    end
    do
        local x = 100*math.cos(bearing+math.pi/2)
        local y = -50*math.sin(bearing+math.pi/2)
        render.drawText(x*1.2, y*1.2-20, S2, 1)
        local tx, ty = -y*0.05, x*0.05
        render.drawPoly({{x = -tx, y = -ty},{x = x, y = y},{x = tx, y = ty}})
    end
    render.popMatrix()

end)

end