-- LUA Script - precede every function and global member with lowercase name of script + '_main'
--
-- vsync = 1 in setup.ini strongly recommended!
--
------------------------
-- user editable bits --
------------------------
local maxSpeed      = 20      -- reversing is limited to half maxSpeed
local acceleration  = 0.05    -- this is per frame

-- sound stuff
local baseSoundSpeed = 40000   -- nice deep sound for a big truck, make it higher for a pick-up

-- gear changes             G1               G2               G3          
local gearChng = { maxSpeed * 0.25, maxSpeed * 0.44, maxSpeed * 0.66, math.huge }

-- All positioning offsets are relative to vehicle model origin which for best results should be
-- dead centre of the rear axle, this script currently designed for rear wheel drive front wheel 
-- steering 4 wheeled vehicles.  These offsets are for an unscaled model, the script will factor
-- in the scaling factor at runtime so if the default model is scaled already strange results
-- *will* be expected.  

-- 'bumpers' effectively, i.e. offset from origin to front and rear of vehicle
local frontOff, rearOff = 90, -70

-- road wheels
local wheelOffsets = 
        {{ x = -29.0, y = 0, z = 77.0 },  -- left  front
         { x = -29.0, y = 0, z =   -55.0 },  -- left  rear
         { x =  30.0, y = 0, z = 77.0 },  -- right front
         { x =  30.0, y = 0, z =   -55.0 }   -- right rear
        }

-- these offsets are for 
local doorOffs = { passenger = { x = -45, y = 0, z = 65 },
                   drivers   = { x =  45, y = 0, z = 65 } }

-- steering wheel				   
local sw_offs = { x = 18.5, y = 25, z = 65.0 }
local swPitch = 30

-- player positioning
local tpZoff, tpYoff = 380, 120
local fpXoff, fpYoff, fpZoff = -23, 30, 65

-- vehicle terrain limits
local maxRoll, maxPitch = 45, 60

-------------------------------------------------------
-- Edit anything below here at your own peril.  :-)  --
-------------------------------------------------------   

local truck_vars = {}

local Q = require "scriptbank\\quatlib"
local U = require "scriptbank\\utillib"
local P = require "scriptbank\\physlib"

local sin  = math.sin
local cos  = math.cos 
local rad  = math.rad
local deg  = math.deg
local abs  = math.abs
local asin = math.asin
local atan = math.atan2
local modf = math.modf
local sqrt = math.sqrt
local sub  = string.sub
local max  = math.max
local min  = math.min				   
local names = {}
local samplesLoaded  = false

function truck021_init_name( e, name )
    Include( "quatlib.lua" )
	Include( "utillib.lua" )
	Include( "physlib.lua" )

	names[ e ] = name
	
	if not samplesLoaded then
		LoadGlobalSound( "audiobank\\Truck021\\Start.wav", 0 )
		LoadGlobalSound( "audiobank\\Truck021\\Run.wav",   1 )
		LoadGlobalSound( "audiobank\\Truck021\\Stop.wav",  2 )
		LoadGlobalSound( "audiobank\\Truck021\\Gear.wav",  3 )
		samplesLoaded = true
	end
end	

local function getDims( obj )
		
	local xmin, ymin, zmin, xmax, ymax, zmax = GetObjectColBox( obj ) 

	-- get scale factors for object
	local sx, sy, sz = GetObjectScales( obj )
	
	-- now work out width, height, length and mass
	local w, h, l = (xmax - xmin) * sx, (ymax - ymin) * sy, (zmax - zmin) * sz
	
	return { w = w, h = h, l = l, sx = sx, sy = sy, sz = sz }						
end

function Truck021AddWheel( e, name )
    for k, v in pairs( truck_vars ) do
        if #v.wheels < 4 then
			if sub(v.name,1,6) == sub(name,1,6) then
				local Obj = g_Entity[e].obj
				local Dims = getDims( Obj )
				
                v.wheels[#v.wheels + 1] = { Ent = e, Obj = Obj, hght = Dims.h, quat = nil }
                return true
			end
        end
    end    
end

function Truck021AddSteeringWheel( e, name )
	for k, v in pairs( truck_vars ) do
        if v.steering == nil then
			if sub(v.name,1,6) == sub(name,1,6) then
				local Obj = g_Entity[e].obj
				
                v.steering = { Ent = e, Obj = Obj, quat = nil }
                return true
			end
        end
    end    
end


local wheelHeights = {}

local function calcAngle( h1, h2, l )
    return asin( ( h1 - h2 ) / l )
end

local function GetHeightUnderWheel(v, num, xo, yo, zo)
	local x, y, z = v.x + xo, v.y + yo, v.z + zo
	
	wheelHeights[ num ].obj = IntersectAll( x, y - ( 5 * v.dims.sy ), z, x, y - v.wheels[ num ].hght, z, v.wheels[num].Obj )
	if wheelHeights[ num ].obj and wheelHeights[ num ].obj ~= 0 then
		return( GetIntersectCollisionY())
	else
		return GetTerrainHeight( x, z )
	end
end

local function GetWheelHeights( v, xA, yA, zA )

    local xo, yo, zo
    -- given proposed vehicle position and current angles
    -- calculate the terrain heights under the wheels
    local avgHeight, avgRoll, avgPitch = 0, 0, 0

    for i = 1, 4 do	
		wheelHeights[ i ] = {}

        local wo = wheelOffsets[i]
    
        xo, yo, zo = U.Rotate3D( wo.x * v.dims.sx, wo.y * v.dims.sy, wo.z * v.dims.sz, xA, yA, zA )

        wheelHeights[i].hgt = GetHeightUnderWheel( v, i, xo, yo, zo ) + v.wheels[i].hght / 2
        
        avgHeight = avgHeight + wheelHeights[i].hgt
        
        wheelHeights[i].hgt = ( v.y + yo ) - wheelHeights[i].hgt 
    end
    
    avgHeight = avgHeight / 4	
	
    -- now work out vehicle angles
    local ax1 = calcAngle( wheelHeights[1].hgt, wheelHeights[3].hgt, 
	                       wheelOffsets[3].x * v.dims.sx - wheelOffsets[1].x * v.dims.sx );
						   
    local ax2 = calcAngle( wheelHeights[2].hgt, wheelHeights[4].hgt, 
	                       wheelOffsets[4].x * v.dims.sx - wheelOffsets[2].x * v.dims.sx );
    
    avgRoll = (ax1 + ax2) / 2
	
	if avgRoll > rad( maxRoll) then 
		avgRoll = rad( maxRoll)
		v.speed = v.speed / 2
	end
	if avgRoll < rad(-maxRoll) then 
		avgRoll = rad(-maxRoll)
		v.speed = v.speed / 2
	end
    
    local p1 = calcAngle( wheelHeights[1].hgt, wheelHeights[2].hgt, 
	                      wheelOffsets[1].z * v.dims.sz + wheelOffsets[2].z * v.dims.sz );
						  
    local p2 = calcAngle( wheelHeights[3].hgt, wheelHeights[4].hgt, 
	                      wheelOffsets[3].z * v.dims.sz + wheelOffsets[4].z * v.dims.sz );
    
    avgPitch = (p1 + p2) / 2
	
	if avgPitch > rad( maxPitch) then avgPitch = rad( maxPitch) end
	if avgPitch < rad(-maxPitch) then avgPitch = rad(-maxPitch) end
	
	-- correct for axle offset
	local L = ( wheelOffsets[ 1 ].z * v.dims.sz - wheelOffsets[ 2 ].z * v.dims.sz ) / 2
	local ycor = sin( avgPitch ) * L
	
    return avgHeight + ycor, avgPitch, avgRoll
end

local turnDir = { 'F', 'R', 'F', 'R' }

local rotQuat = nil
local finQuat = nil

local function PositionWheel( num, v, xA, yA, zA )

    local wo = wheelOffsets[num]
    
    local xo, yo, zo = U.Rotate3D( wo.x * v.dims.sx, wo.y * v.dims.sy, wo.z * v.dims.sz, xA, yA, zA )
    
    local suspensionOffset = wheelHeights[num].hgt
    
    if suspensionOffset > 4 then suspensionOffset = 4 end
    if suspensionOffset < -4 then suspensionOffset = -4 end
    
    ResetPosition( v.wheels[num].Ent, v.x + xo, 
                                      v.y + yo - suspensionOffset, 
                                      v.z + zo );
        
    if turnDir[num] == 'F' then
        if num == 1 then
            finQuat = Q.FromEuler( 0, rad(  v.turnAng ), 0 )
        else
            finQuat = Q.FromEuler( 0, rad( -v.turnAng ), rad( 180 ))
        end
    else
        if num == 2 then
            finQuat = Q.FromEuler( 0, 0, 0 )
        else
            finQuat = Q.FromEuler( 0, 0, rad( 180 ) )
        end
    end
    
    if num > 2 then suspensionOffset = -suspensionOffset end
    
    finQuat = Q.Mul( v.quat, finQuat )
    
    if num > 2 then
        rotQuat = Q.FromEuler( rad(  v.rotAng ), 0, rad( suspensionOffset * 2 ) )
    else
        rotQuat = Q.FromEuler( rad( -v.rotAng ), 0, rad( suspensionOffset * 2 ) )
    end
    
    v.rotAng = v.rotAng - v.speed / 5

    if v.rotAng < -180 then 
        v.rotAng = v.rotAng + 360
    elseif v.rotAng > 180 then
        v.rotAng = v.rotAng - 360
    end
    
    finQuat = Q.Mul( finQuat, rotQuat )

    local xA, yA, zA = Q.ToEuler( finQuat )
    
    ResetRotation( v.wheels[num].Ent, deg( xA ), deg( yA ), deg( zA ) )
end

local function PositionWheels( v, xA, yA, zA )
    for i = 1, 4 do
        PositionWheel( i, v, xA, yA, zA )
    end
end

local pitchQ = Q.FromEuler( rad( swPitch ), 0, 0 )

local function PositionSteering( v, xA, yA, zA )
	local xo, yo, zo = U.Rotate3D( sw_offs.x * v.dims.sx, sw_offs.y * v.dims.sy, sw_offs.z * v.dims.sz, xA, yA, zA )

	PositionObject( v.steering.Obj , v.x + xo, v.y + yo, v.z + zo )
	
	local quat = Q.Mul( Q.FromEuler( xA, yA, zA ), pitchQ )
	
	quat = Q.Mul( quat, Q.FromEuler( 0, 0, -rad( v.turnAng * 4.5 ) ) )						
	local sxA, syA, szA = Q.ToEuler( quat )					
	RotateObject( v.steering.Obj, deg( sxA ), deg( syA ), deg( szA ) )
end

local function PositionVehicle( e, v, xA, yA, zA )
    
	local ay = deg(yA)
	
	-- this weird looking code is to make sure the Euler 'gimbal lock' position
	-- is avoided.  For GG this is at -90 and +90 degrees in Y axis rotation.
	if abs( ay - 90 ) < 0.001  then	
		ay = 89.999 
	elseif abs( ay + 90 ) < 0.001 then
		ay = -89.999
	end
	
	CollisionOff( e )
	PositionObject( v.obj , v.x, v.y, v.z )
	RotateObject( v.obj, deg( xA ), ay, deg( zA ) )
	CollisionOn( e )
	PositionSteering( v, xA, yA, zA )
end

local collListForward  = {}
local collListBackward = {}
	
local RayCastEnt = IntersectAll
local RayCastTer = RayTerrain
local objectHit  = 0 
local terrainHit = false
local delayCheck = math.huge

local function AnythingThere( x, y, z, vx, vy, vz )
	terrainHit = false
	objectHit = RayCastEnt( x, y, z, x + vx, y + vy, z + vz, 0 ) 
	
	if objectHit ~= nil and objectHit ~= 0 then return true end
	
	if RayCastTer( x, y, z, x + vx, y + vy, z + vz ) == 1 then 
		terrainHit = true 
	end
	return terrainHit
end

local function ProcessHit( v, col )
	if terrainHit then
		if col == 'left' or col == 'right' then
			v.speed = 0
		end
	else
		local e = P.ObjectToEntity( objectHit )	
		
		if e ~= nil and ai_bot_state[ e ] ~= nil then
			SetEntityHealth( e, 0 )
			-- slightly slow down
			v.speed = v.speed * 0.9
			-- TBD, sound effect of collision?
			
		else -- assume farah has met his mountain
			v.speed = 0
			if PositionCollision ~= nil then 
				PositionCollision( GetIntersectCollisionX(), 
				                   GetIntersectCollisionY(), 
								   GetIntersectCollisionZ() )
			end
			-- TBD, process effect of collision, e.g. sound effect or damage to vehicle?
		end
	end
end

local function CheckForCollision( v, xA, yA, zA )
	if collListForward[ v.obj ] == nil then
		local fOff = frontOff * v.dims.sz
		collListForward[ v.obj ] = 
			{ left   = { x = -v.dims.w / 2, y = 5, z = fOff},
			  centre = { x =   0,           y = 5, z = fOff},
			  right  = { x =  v.dims.w / 2, y = 5, z = fOff }, 
			}
	end
	if collListBackward[ v.obj ] == nil then
		local rOff = rearOff * v.dims.sz 
		collListBackward[ v.obj ] =
			{ left   = { x = -v.dims.w / 2, y = 5, z = rOff },
			  centre = { x =   0,           y = 5, z = rOff },
			  right  = { x =  v.dims.w / 2, y = 5, z = rOff } 
			}
	end

	local colls, dist, diag
	
	if v.speed == 0 then
		objectHit = 0
		return
		
	elseif v.speed > 0 then
		-- going forwards so cast rays from front corners
		colls = collListForward[ v.obj ]
		dist  = max( 10, v.speed * 2 )
		diag  = v.dims.w
	else
		colls = collListBackward[ v.obj ]
		dist  = min( -10, v.speed * 2 )
		diag  = v.dims.w
	end
	
	for yOff = 80, 0, -20 do
		for k, w in pairs( colls ) do
		
			local vx, vy, vz = U.Rotate3D( 0, 0, dist * v.dims.sz, xA, yA, zA )
			local fx, fy, fz = U.Rotate3D( w.x, w.y + yOff * v.dims.sy, w.z, xA, yA, zA )

			if yOff == 0 then
				-- Check for cliff hanger
				if not AnythingThere( v.x + fx, v.y + fy, v.z + fz, 0, -150 * v.dims.sy, 0 ) then
					v.speed = 0
					return
				end
			end
			
			-- next check straight ahead	
			if AnythingThere( v.x + fx, v.y + fy, v.z + fz, vx, vy, vz ) then
				ProcessHit( v, k ) 
				if v.speed == 0 then return end
			end
		
			-- then diagonals
			if k == 'left' then
				vx, vy, vz = U.Rotate3D( diag, 0, dist, xA, yA, zA )
				if AnythingThere( v.x + fx, v.y + fy, v.z + fz, vx, vy, vz ) then
					ProcessHit( v, k .. " diag" ) 
					if v.speed == 0 then return end
				end
			end
			
			if k == 'right' then
				vx, vy, vz = U.Rotate3D( -diag, 0, dist, xA, yA, zA )
				if AnythingThere( v.x + fx, v.y + fy, v.z + fz, vx, vy, vz ) then
					ProcessHit( v, k .. " diag" ) 
					if v.speed == 0 then return end
				end
			end
		end
	end
end


local function MoveVehicle( v, e, td )
	-- move vehicle way out of the way for now
	CollisionOff( e )
	PositionObject( v.obj , v.x + 1000, 10000, v.z + 1000 )
	CollisionOn( e )
	
	if v.speed ~= 0 then
	
		-- check for collisions, for now if potential collision detected 
		local xA, yA, zA = Q.ToEuler( Q.Mul( v.quat, 
		                                     Q.FromEuler( v.curPitch, 0, v.curRoll ) ) )
		CheckForCollision( v, xA, yA, zA )
						
		local mX, mY, mZ
		if v.speed ~= 0 then
			mX, mY, mZ = U.Rotate3D( 0, 0, td * v.speed, xA, yA, zA )
			v.x, v.y, v.z = v.x + mX, v.y + mY, v.z + mZ
		else
			mX, mY, mZ = U.Rotate3D( 0, 0, 1, xA, yA, zA )
		end
       
		v.vmAng = deg( atan( mX, mZ ) )
    
        -- we need to turn the vehicle a small amount each
        -- frame until we are pointing in the right direction

        v.quat = Q.Mul( v.quat, Q.FromEuler( 0, rad( v.turnAng * td / ( 15 * v.dims.sz) ) * (v.speed / maxSpeed), 0 ) )
    end
end

local function GotEnts( e, v )
    if #v.wheels ~= 4 then
        PromptLocal( e, "Not enough wheel entities!" )
        return false
    end
	if v.steering == nil then
		PromptLocal( e, "No steering wheel" )
		return false
	end
    return true
end

local function RealWorldYAngle( xa, ya, za )  
	-- Tricky to explain but basically g_PlayerAngY is the real-world
	-- angle, i.e. 0-359 degrees, whereas the Euler angle for an entity
    -- returned by GetObjectPosAng is not.
	-- In order to get the 'real-world' equivalent we need to do some math.

	-- first rotate a unit 'facing forward' vector by the Euler angles
	local xv, _, zv = U.Rotate3D( 0, 0, 1,  xa, ya, za )
	
	-- now work out the angle from the x and z components of the result
	return atan( xv, zv )
end			
   
local function RevRealWorldYAngle( xa, ya, za )  
	local xv, _, zv = U.Rotate3D( 0, 0, -1,  xa, ya, za )
	return atan( xv, zv )
end			

local function AttachPlayer( v, xA, yA, zA, inCab )

	local cx, cy, cz, ax, ay, az
	local xo, yo, zo
	
	xo, yo, zo = U.Rotate3D( fpXoff * v.dims.sx, fpYoff * v.dims.sy, fpZoff * v.dims.sz, xA, yA, zA )
	local y = GetTerrainHeight( v.x + xo, v.z + zo )

	if  y < 0 then return end

	cx, cy, cz = v.x + xo, v.y + yo, v.z + zo
	SetFreezePosition( cx, cy, cz )
	
	local pxA, pyA, pzA = Q.ToEuler( Q.Mul( Q.FromEuler( xA, yA, zA ),
   		                                    Q.FromEuler( 0, rad(v.turnAng / 8), 0 ) ) )
		
	ax, ay, az = deg(pxA), deg(pyA), deg(pzA) 		
	
	SetFreezeAngle( ax, ay, az )
	TransportToFreezePosition()
	
	if not inCab then
		local tweak = abs( v.speed * 5 ) * v.dims.sz
		
	    if v.speed >= 0 then
			xo, yo, zo = U.Rotate3D( v.turnAng * 2.5 * v.dims.sx, 0, -(tpZoff * v.dims.sz + tweak), xA, yA, zA )
		else
			xo, yo, zo = U.Rotate3D( v.turnAng * 2.5 * v.dims.sx, 0, tpZoff * v.dims.sz + tweak, xA, yA, zA )
		end
		local y = GetTerrainHeight( v.x + xo, v.z + zo )

		if y < 0 then return end
		
		if v.y + yo > y then y = v.y + yo end
		
		cx, cy, cz =  v.x + xo, y + tpYoff * v.dims.sy + tweak, v.z + zo
		
		if v.speed >=0 then 
			ax, ay, az = 25 - v.speed, deg( RealWorldYAngle( pxA, pyA, pzA )), 0
		else
			pxA, pyA, pzA = Q.ToEuler( Q.Mul( Q.FromEuler( xA, yA, zA ),
   		                               Q.FromEuler( 0, rad(-v.turnAng / 1.5), 0 ) ) )

			ax, ay, az = 25 + v.speed, deg( RevRealWorldYAngle( pxA, pyA, pzA )), 0
		end
	end
	
	SetCameraPosition ( 0, cx, cy, cz )
	SetCameraAngle ( 0, ax, ay, az )
end


local inCab       = true
local QkeyPressed = false
local EkeyPressed = false


local currGear = 0   

local function HandleGears( v )
	
	if v.speed > gearChng[ currGear + 1 ] then
		currGear = currGear + 1
		PlayGlobalSound( 3 )
	elseif v.speed <= 0 then -- must be reverse or stopped
		currGear = 0
	elseif currGear >= 1 and v.speed < gearChng[ currGear ] then
		currGear = currGear - 1
		PlayGlobalSound( 3 )	
	end

	if currGear > 0 then 
		return v.speed - gearChng[ currGear ]
	else
		return abs ( v.speed )
	end
end

local function DriveControls( v, xA, yA, zA, td )
	-- accelerate/forward
    if v.speed < maxSpeed and g_KeyPressW == 1 then
		if v.speed < 0 then
			v.speed = v.speed + acceleration * 2 * td
			-- TBD add braking sound here?
		else
			v.speed = v.speed + acceleration * td
		end
		local snd = HandleGears( v )
		SetGlobalSoundSpeed( 1, baseSoundSpeed + snd * 4000 ) 

	elseif v.speed > 0 then 
		v.speed = v.speed - acceleration * td
		local snd = HandleGears( v )
		SetGlobalSoundSpeed( 1, baseSoundSpeed + snd * 4000 )
    end
	
	-- decelerate/reverse
    if v.speed > -maxSpeed / 2 and g_KeyPressS == 1 then
		if v.speed > 0 then
			v.speed = v.speed - acceleration * 2 * td
			-- TBD add braking sound here?
		else
			v.speed = v.speed - acceleration * td
		end
		local snd = HandleGears( v )
		SetGlobalSoundSpeed( 1, baseSoundSpeed + snd * 4000 )
		
	elseif v.speed < 0 then
		v.speed = v.speed + acceleration * td
		local snd = HandleGears( v )
		SetGlobalSoundSpeed( 1, baseSoundSpeed + snd * 4000 )
    end
end	

local function PlayerControl( v, xA, yA, zA, td )
	g_suspendplayercontrols = 1
	
	-- Turn right
    if g_KeyPressD == 1 then
        if v.turnAng < 35 then
            v.turnAng = v.turnAng + 1.3 * td 
        end
    elseif v.turnAng > 0 and v.speed ~= 0 then
        v.turnAng = v.turnAng - 1.17 * td
    end
	
	-- turn left
    if g_KeyPressA == 1 then
        if v.turnAng > -35 then
            v.turnAng = v.turnAng - 1.3 * td 
        end
    elseif v.turnAng < 0 and v.speed ~= 0 then
        v.turnAng = v.turnAng + 1.17 * td
    end

	-- change viewpoint
	if g_KeyPressQ == 1 then
		if not QkeyPressed then
			inCab = not inCab
			QkeyPressed = true
		end
	else
		QkeyPressed = false
	end
	
	-- exit 
	if g_KeyPressE == 1 and abs(v.speed) < 1 then
		if not EkeyPressed then
			v.state = 'stop'
			StopGlobalSound( 1 )
			PlayGlobalSound( 2 )
			SetGlobalSoundSpeed( 2, baseSoundSpeed )
			v.timer = g_Time + 3000
			vispeed = 0

			EkeyPressed = true
		end
	else
		EkeyPressed = false
	end
end

local function SmoothMotion( v )
	if v.curPitch ~= v.tgtPitch then
		local pitchDiff = v.tgtPitch - v.curPitch
		if abs( pitchDiff ) < 0.001 then 
			v.curPitch = v.tgtPitch
		else
			v.curPitch = v.curPitch + pitchDiff / 2
		end
	end
	if v.curRoll ~= v.tgtRoll then
		local rollDiff = v.tgtRoll - v.curRoll
		if abs( rollDiff ) < 0.001 then
			v.curRoll = v.tgtRoll
		else
			v.curRoll = v.curRoll + rollDiff / 2
		end
	end
	if v.tgtY ~= v.y then 
		local ydiff = v.tgtY - v.y
		if abs( ydiff ) < 0.01 then
			v.y =  v.tgtY 
		else
			v.y = v.y + ydiff / 2
		end
	end
end

local timeLastFrame = nil
local timeDiff      = 0

function truck021_main(e)

    local vehicle = truck_vars[e]
	
    if vehicle == nil then 
        local Ent = g_Entity[e]
        local x, y, z, xA, yA, zA = GetObjectPosAng( Ent.obj )
        truck_vars[e] = 
            { state = 'init', name = names[e], obj = Ent.obj, 
              wheels = {},
			  steering = nil,
              x = x, y = y, z = z,                               -- actual position
              quat = Q.FromEuler( rad(xA) , rad(yA), rad(zA) ),  -- actual rotation
			  dims = getDims( Ent.obj ),
              vmAng = 0, rotAng = 0, turnAng = 0,
			  curPitch = 0, tgtPitch = 0,
			  curRoll  = 0, tgtRoll  = 0,
              speed = 0, timer = g_Time + 4000
            }

        return
    end
    
	
    if vehicle.state == 'init' and GotEnts( e, vehicle ) then
	
	    local xA, yA, zA = Q.ToEuler( vehicle.quat )
		
        vehicle.tgtY, vehicle.tgtPitch, vehicle.tgtRoll = GetWheelHeights( vehicle, xA, yA, zA )
		
		SmoothMotion( vehicle )
		
        xA, yA, zA = Q.ToEuler( Q.Mul( vehicle.quat, 
		                               Q.FromEuler( vehicle.curPitch, 0, vehicle.curRoll ) ) )

        PositionVehicle( e, vehicle, xA, yA, zA )

        PositionWheels( vehicle, xA, yA, zA )
		
		if g_Time > vehicle.timer then
			vehicle.state = 'idle'
		end
		
    elseif vehicle.state == 'idle' then

		-- first check if we are in the general area of the vehicle 
		if U.PlayerLookingNear( e, 300, 170 ) then
		
			-- if so check if we are stood by either the drivers door or the
			-- passenger door
			local xA, yA, zA = Q.ToEuler( Q.Mul( vehicle.quat, 
		                                         Q.FromEuler( vehicle.curPitch, 0, vehicle.curRoll ) ) )
			local dofs = doorOffs.drivers
			local xo, yo, zo = U.Rotate3D( dofs.x * vehicle.dims.sx, 
			                               dofs.y * vehicle.dims.sy, 
										   dofs.z * vehicle.dims.sz, xA, yA, zA )
			local nearDoor = U.PlayerCloserThanPos( vehicle.x + xo, 
			                                        vehicle.y + yo, 
									                vehicle.z + zo, max( 50, 50 *  vehicle.dims.sy  ) )
            if not nearDoor then
				dofs = doorOffs.passenger
				xo, yo, zo = U.Rotate3D( dofs.x * vehicle.dims.sx,
                       				     dofs.y * vehicle.dims.sy, 
										 dofs.z * vehicle.dims.sz, xA, yA, zA )
			    nearDoor = U.PlayerCloserThanPos( vehicle.x + xo, 
			                                      vehicle.y + yo, 
									              vehicle.z + zo, max( 50, 50 * vehicle.dims.sy ) )
			end
			
			if nearDoor then
				Prompt( "Press E key to drive me!" )
				if g_KeyPressE == 1 then
					if not EkeyPressed then
						SetPlayerWeapons(0)
						SetCameraOverride( 3 )
                                                Hide( GetGamePlayerControlThirdpersonCharactere() )
						vehicle.state = 'start'
						EkeyPressed = true
						PlayGlobalSound( 0 )
						SetGlobalSoundSpeed( 0, baseSoundSpeed )
						vehicle.timer = g_Time + 3000
					end
				else
					EkeyPressed = false
				end
			end
		end
		
	elseif vehicle.state == 'start' then
	
		local xA, yA, zA = Q.ToEuler( Q.Mul( vehicle.quat, 
		                                     Q.FromEuler( vehicle.curPitch, 0, vehicle.curRoll ) ) )

		vehicle.speed = 0
		AttachPlayer( vehicle, xA, yA, zA, inCab )

		if g_Time > vehicle.timer then
			LoopGlobalSound( 1 )
			SetGlobalSoundSpeed( 1, baseSoundSpeed )
			vehicle.state = 'drive'
		end
		PlayerControl( vehicle, xA, yA, zA, timeDiff )
		PositionSteering( vehicle, xA, yA, zA )
		PositionWheels( vehicle, xA, yA, zA )

	elseif vehicle.state == 'drive' then

		local timeThisFrame = g_Time
		
		if timeLastFrame == nil then 
			timeLastFrame = timeThisFrame
			timeDiff = 1
		else
			timeDiff = ( timeThisFrame - timeLastFrame ) / 20
			timeLastFrame = timeThisFrame
		end
			
		MoveVehicle( vehicle, e, timeDiff ) 
	
        local xA, yA, zA = Q.ToEuler( Q.Mul( vehicle.quat, 
		                               Q.FromEuler( vehicle.curPitch, 0, vehicle.curRoll ) ) )
									   
        vehicle.tgtY, vehicle.tgtPitch, vehicle.tgtRoll = GetWheelHeights( vehicle, xA, yA, zA )
				
		SmoothMotion( vehicle )
		
        xA, yA, zA = Q.ToEuler( Q.Mul( vehicle.quat, 
		                               Q.FromEuler( vehicle.curPitch, 0, vehicle.curRoll ) ) )
								   
        PositionVehicle( e, vehicle, xA, yA, zA ) 

	    PositionWheels( vehicle, xA, yA, zA )

		AttachPlayer( vehicle, xA, yA, zA, inCab )
						
		PlayerControl( vehicle, xA, yA, zA, timeDiff )	
		DriveControls( vehicle, xA, yA, zA, timeDiff )

	elseif vehicle.state == 'stop' then
	
		local xA, yA, zA = Q.ToEuler( Q.Mul( vehicle.quat, 
		                                     Q.FromEuler( vehicle.curPitch, 0, vehicle.curRoll ) ) )

		AttachPlayer( vehicle, xA, yA, zA, inCab )
		
		PositionSteering( vehicle, xA, yA, zA )
	
		if g_Time > vehicle.timer then
		
			SetCameraOverride( 0 )
			SetPlayerWeapons(1)
                        Show( GetGamePlayerControlThirdpersonCharactere() )
			
			local dofs = doorOffs.drivers
			local xo, yo, zo = U.Rotate3D( dofs.x, dofs.y, dofs.z, xA, yA, zA )
			
			local px, py, pz = vehicle.x + xo, vehicle.y + yo + 40, vehicle.z + zo
			if py < GetTerrainHeight( px, pz ) then py = GetTerrainHeight( px, pz ) + 40 end 
			SetFreezePosition( px, py, pz )
			SetFreezeAngle( 0, vehicle.vmAng, 0 )
			TransportToFreezePosition()
			
			vehicle.state = 'idle'
			timeLastFrame = nil
		end		
    end
end