Binding KeyCode.ButtonR2 or KeyCode.ButtonL2 while player is in vehicle seat causes acceleration or deceleration permanently

Quenty · January 8, 2019, 9:31pm

Binding KeyCode.ButtonR2 or KeyCode.ButtonL2 while player is in vehicle seat causes acceleration or deceleration permanently.

This causes vehicles to accelerate permanently even after leaving and re-entering the seat.

Steps to reproduce

Have player sit in vehicle seat
Hold down W to get Throttle stuck forwards
Bind ButtonR2 at Enum.ContextActionPriority.High.Value
Check Throttle, it’ll be stuck at 1
Expected behavior: Any acceleration from ButtonR2 is removed

Why I think this happens

See this code, where we blindly bind OnThrottleAccel().

note: Although on closer inspection, I’m not sure this is the code handling vehicle seats, since this appears to not be valid code.

github.com

Roblox/Core-Scripts/blob/master/PlayerScripts/StarterPlayerScripts_NewStructure/RobloxPlayerScript/ControlScript/VehicleController.lua#L51




function VehicleController:Enable(enable, vehicleSeat)
	if enable == self.enabled and vehicleSeat == self.vehicleSeat then
		return
	end
	
	if enable then
		if vehicleSeat then
			self.vehicleSeat = vehicleSeat
			if useTriggersForThrottle then
				ContextActionService:BindAction("throttleAccel", (function() self:OnThrottleAccel() end), false, Enum.KeyCode.ButtonR2)
				ContextActionService:BindAction("throttleDeccel", (function() self:OnThrottleDeccel() end), false, Enum.KeyCode.ButtonL2)
			end
			ContextActionService:BindAction("arrowSteerRight", (function() self:OnSteerRight() end), false, Enum.KeyCode.Right)
			ContextActionService:BindAction("arrowSteerLeft", (function() self:OnSteerLeft() end), false, Enum.KeyCode.Left)
		end
	else
		if useTriggersForThrottle then
			ContextActionService:UnbindAction("throttleAccel")
			ContextActionService:UnbindAction("throttleDeccel")
		end

However, OnThrottleAccel does not handle the case where UserInputState.Cancel occurs, which is what happens here.

github.com

Roblox/Core-Scripts/blob/425d2d641bdc4b6c1104a9d5f6c53c9ea758c5cb/PlayerScripts/StarterPlayerScripts_NewStructure/RobloxPlayerScript/ControlScript/VehicleController.lua#L69


			ContextActionService:UnbindAction("throttleAccel")
			ContextActionService:UnbindAction("throttleDeccel")
		end
		ContextActionService:UnbindAction("arrowSteerRight")
		ContextActionService:UnbindAction("arrowSteerLeft")
		self.vehicleSeat = nil
	end
end


function VehicleController:OnThrottleAccel(actionName, inputState, inputObject)	
	self.acceleration = (inputState ~= Enum.UserInputState.End) and -1 or 0
	self.throttle = self.acceleration + self.decceleration
end


function VehicleController:OnThrottleDeccel(actionName, inputState, inputObject)
	self.decceleration = (inputState ~= Enum.UserInputState.End) and 1 or 0
	self.throttle = self.acceleration + self.decceleration
end


function VehicleController:OnSteerRight(actionName, inputState, inputObject)
	self.turningRight = (inputState ~= Enum.UserInputState.End) and 1 or 0

This occurs on the current version of Roblox.

cloakedyoshi · February 21, 2019, 5:03am

Can confirm, this bug is still live. I’ve been trying to figure the reason for this behavior in my game for the past three months, I eventually narrowed it down to binding ButtonL2.

This is incredibly annoying, not intuitive in the slightest, and should be addressed ASAP.

Airennor · February 21, 2019, 6:25am

A similar bug is while you’re accelerating, pull out a tool for this same exact permanent cycle. I will get out to stop then get back in without pressing the “W” key and it will automatically go back to the previous acceleration point. I’m unsure if there is a way around this one.

cloakedyoshi · August 18, 2019, 11:58pm

Any word on solving this bug?

It is still active nearly half a year later with no input from staff. It makes designing cars very difficult.