Helps you find what axis is what with the joystick module in Starfall, spawn on a Starfall screen

joystickhelper.lua

--@name Joystick Helper
--@author Cheezus
--@shared

if SERVER then
    local ent = chip():isWeldedTo()

    if isValid(ent) and ent:getClass() == "starfall_screen" then
        ent:linkComponent(chip())
    end
else
    if not joystick then
        print("Joystick module not installed")

        return
    end

    if joystick.numJoysticks() == 0 then
        print("No usable devices connected")

        return
    end

    -- Returns a table containing only keys which have a value different from the old table
    local function getDiff(old, new)
        local diff = {}

        for k, v in pairs(new) do
            if old[k] ~= v then
                diff[k] = v
            end
        end

        return diff
    end

    local function getJoystickData(deviceID)
        local data = {}
        data.axes = {}
        data.buttons = {}
        data.povs = {}

        for i = 0, 31 do
            data.axes[i] = joystick.getAxis(deviceID, i)
        end

        for i = 0, 31 do
            data.buttons[i] = joystick.getButton(deviceID, i)
        end

        for i = 0, 31 do
            data.povs[i] = joystick.getPov(deviceID, i)
        end

        return data
    end

    local devices = {}

    -- Get default device values to compare against later
    for i = 0, 2 do
        devices[i] = {}
        devices[i].joystickData = getJoystickData(i)

        local detectedInputs = {}
        detectedInputs.axes = {}
        detectedInputs.buttons = {}
        detectedInputs.povs = {}

        devices[i].detectedInputs = detectedInputs
    end

    timer.create("detectAxes", 0.1, 0, function()
        for deviceID, device in pairs(devices) do
            local newData = getJoystickData(deviceID)

            local axesDiff = getDiff(device.joystickData.axes, newData.axes)
            local buttonsDiff = getDiff(device.joystickData.buttons, newData.buttons)
            local povsDiff = getDiff(device.joystickData.povs, newData.povs)

            for k, v in pairs(axesDiff) do
                device.detectedInputs.axes[k] = v
            end

            for k, v in pairs(buttonsDiff) do
                device.detectedInputs.buttons[k] = v
            end

            --for k, v in pairs(povsDiff) do
            --    device.detectedInputs.povs[k] = v
            --end
        end
    end)

    local WHITE = Color(255, 255, 255)
    local RED = Color(255, 100, 100)
    local GREEN = Color(100, 255, 100)
    local BLUE = Color(100, 100, 255)

    hook.add("render", "data", function()
        for deviceID, device in pairs(devices) do
            render.setColor(WHITE)

            render.drawText(deviceID * 256, 0, "Device " .. deviceID, deviceID)
            render.drawText(deviceID * 256, 14, joystick.getName(deviceID), deviceID)
            render.drawLine(0, 30, 512, 30)

            local row = 0

            for dataSetName, dataSet in pairs(device.detectedInputs) do
                for inputID in pairs(dataSet) do
                    local value

                    if dataSetName == "axes" then
                        value = string.format("Axis %s: %d", inputID, joystick.getAxis(deviceID, inputID))

                        render.setColor(RED)
                    elseif dataSetName == "buttons" then
                        value = string.format("Button %s: %d", inputID, joystick.getButton(deviceID, inputID) > 0 and 1 or 0)

                        render.setColor(GREEN)
                    elseif dataSetName == "povs" then
                        value = string.format("POV %s: %d", inputID, joystick.getPov(deviceID, inputID))

                        render.setColor(BLUE)
                    end

                    render.drawText(deviceID * 256, 32 + row * 12, value, deviceID)

                    row = row + 1
                end
            end
        end
    end)
end