Is there some way to see where all touch points on a touchscreen currently are?

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#1

I’ve been browsing around the wiki a bit and can’t seem to figure out how to find all locations of current touch inputs without having to manually do some stuff w/ InputBegan which is hacky at best. Ideally I’d like to know when a touch input begins & where it drags to, and the moment it stops being touched. These are all things you can do w/ InputBegan/Changed/Ended but that has edge cases/inaccuracies where you can’t guarantee that the same finger is causing the Began/Changed/Ended events. Is there some sort of API I can’t find that does this or something?

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#2

InputObjects persist for the lifetime of the “finger” on the screen. So you can determine state by storing the start input object and passing it down in a function to compare to the end event. You can quite easily make a global tracker if you needed to.

Comparisons like startInputObject == inputObject is quite normal for me.

Not sure if there’s an easy way to retrieve the global state of touch input objects tho.

edit: should this be in the scripting helpers forum?

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#3

^ this.

Here’s how I’d probably go about doing it (though I’d advocate for just using the events):

local UserInputService = game:GetService("UserInputService")

-- set of all currently active touch points
-- indexes are InputObjects
-- values are Vector3s
local touchPoints = {}

UserInputService.InputBegan:Connect(function(inputObject, gameProcessed)
    if gameProcessed then return end --optional
    if inputObject.UserInputType ~= Enum.UserInputType.Touch then return end

    touchPoints[inputObject] = inputObject.Position
    inputObject.Changed:Connect(function()
        touchPoints[inputObject] = inputObject.Position
    end)
end

UserInputService.InputEnded:Connect(function(inputObject, gameProcessed)
    if gameProcessed then return end --optional
    if inputObject.UserInputType ~= Enum.UserInputType.Touch then return end

    touchPoints[inputObject] = nil
end
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