local ease = {}

function easeGameSpeed(targetSpeed, overTime, callback)
    ease.startedAt      =   getTickCount()
    ease.startSpeed     =   getGameSpeed()
    ease.targetSpeed    =   math.round(targetSpeed, 4, "floor")
    ease.overTime       =   overTime
    ease.callback       =   (type(callback) == "function" or type(callback) == "nil") and (type(callback) == "function" and callback or nil) or nil
    ease.isActive       =   true
end

addEventHandler("onClientRender", root, function()
    if ease.isActive then
        local progress = (getTickCount() - ease.startedAt) / ((ease.startedAt + ease.overTime) - ease.startedAt)
        local currentSpeed = math.round(getGameSpeed(), 1, (ease.startSpeed > ease.targetSpeed and "ceil" or "floor"))

        local X, Y, Z = interpolateBetween(currentSpeed, 0.0, 0.0, ease.targetSpeed, 0.0, 0.0, progress, "InOutQuad")
        X = math.round(X, 4, (ease.startSpeed > ease.targetSpeed and "floor" or "ceil"))
        setGameSpeed(X)
        if X == ease.targetSpeed then
            ease.isActive = false
            if type(ease.callback) == "function" then
                ease.callback();
            end
        end
    end
end)

function math.round(number, decimals, method)
    decimals = decimals or 0
    local factor = 10 ^ decimals
    if (method == "ceil" or method == "floor") then return math[method](number * factor) / factor
    else return tonumber(("%."..decimals.."f"):format(number)) end
end