02-basic-frame.luau

--[[
    02-basic-frame.luau -- Reading Frame Times

    Demonstrates how to read CPU and GPU frame durations.
    Works in both the Roblox Engine and Lute (CLI).
    See example #1 for setup instructions.
]]

local LibMP = require(game and "@game/ReplicatedStorage/LibMP" or "./LibMP")

LibMP.Control:SetFrameLimit(64)
LibMP.Control:EnableProfiler(true)
LibMP.Control:EnableCapture(true)

local function printFrameTimes()
    local session = LibMP.Session.OpenFromLiveData()
    if not session or not session:IsValid() then
        print("Failed to open session")
        if session then session:Dispose() end
        return
    end

    local globalDesc = session:FetchGlobalDesc()
    local frameIdMin = session:GetFrameIdMin()
    local frameIdMax = session:GetFrameIdMax()

    if frameIdMin == 0 and frameIdMax == 0 then
        print("No frames available")
        session:Dispose()
        return
    end

    local framesToPrint = 10
    local startFrame = math.max(frameIdMin, frameIdMax - framesToPrint + 1)

    print(string.format("%-8s %-12s %-12s", "Frame", "CPU (ms)", "GPU (ms)"))
    print(string.rep("-", 34))

    for frameId = startFrame, frameIdMax do
        local desc = session:FetchFrameDesc(frameId)

        local cpuMs = (desc.TickEndCpu - desc.TickStartCpu) * globalDesc.TickToMsCpu
        local gpuMs = (desc.TickEndGpu - desc.TickStartGpu) * globalDesc.TickToMsGpu

        -- GPU times can sometimes be inaccurate; clamp to zero
        gpuMs = math.max(gpuMs, 0)

        print(string.format("%-8d %-12.2f %-12.2f", frameId, cpuMs, gpuMs))
    end

    session:Dispose()
end

if game then
    -- Delay execution to allow the engine to accumulate
    -- frame history on the first activation of MicroProfiler
    task.delay(2, printFrameTimes)
else
    printFrameTimes()
end