Add Framerate Counter (capped at 60)

2026-06-03 16:10:28 +02:00
parent 3c8e9080f3
commit c95a59c771
3 changed files with 352 additions and 0 deletions
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+using UnityEngine;
+using UnityEngine.UI;
+using System.Collections.Generic;
+
+/// <summary>
+/// PerformanceOverlay — displays FPS, frame time, and estimated input lag.
+/// Singleton: only one instance will ever exist. Safe to place in every scene —
+/// duplicates are destroyed automatically. Persists across scene loads.
+/// Requires: a Canvas with a Text (or TMP_Text) component assigned in the Inspector.
+/// </summary>
+public class PerformanceOverlay : MonoBehaviour
+{
+    // ── singleton ────────────────────────────────────────────────────────────
+    public static PerformanceOverlay Instance { get; private set; }
+
+    void Awake()
+    {
+        if (Instance != null && Instance != this)
+        {
+            // A valid instance already exists — destroy this duplicate.
+            Destroy(gameObject);
+            return;
+        }
+
+        Instance = this;
+        DontDestroyOnLoad(gameObject);
+    }
+
+    [Header("UI Reference")]
+    [Tooltip("Assign a UI Text or TextMeshPro Text component here.")]
+    public Text displayText; // swap to TMP_Text if using TextMeshPro
+
+    [Header("FPS Settings")]
+    [Tooltip("How many frames to average over for a smooth FPS reading.")]
+    public int sampleSize = 60;
+
+    [Tooltip("How often (seconds) the display refreshes.")]
+    public float updateInterval = 0.1f;
+
+    [Header("Input Lag Settings")]
+    [Tooltip("Frames of render pipeline latency added on top of frame time.\n" +
+             "Typical values: 0–1 for Forward, 1–2 for Deferred / URP with buffering.")]
+    public int pipelineLatencyFrames = 1;
+
+    [Header("Thresholds (for colour coding)")]
+    public int goodFPS   = 60;
+    public int warningFPS = 30;
+
+    // ── internals ────────────────────────────────────────────────────────────
+    private readonly Queue<float> _frameTimes = new Queue<float>();
+    private float _accumulatedTime;
+    private float _timeSinceLastUpdate;
+
+    // Colour tags (works with both Text and TMP richtext)
+    private const string GREEN  = "<color=#00ff88>";
+    private const string YELLOW = "<color=#ffcc00>";
+    private const string RED    = "<color=#ff4444>";
+    private const string END    = "</color>";
+
+    // ── lifecycle ────────────────────────────────────────────────────────────
+    void Update()
+    {
+        float dt = Time.unscaledDeltaTime;   // unscaled so pausing doesn't skew readings
+
+        // Rolling window
+        _frameTimes.Enqueue(dt);
+        _accumulatedTime += dt;
+        if (_frameTimes.Count > sampleSize)
+            _accumulatedTime -= _frameTimes.Dequeue();
+
+        _timeSinceLastUpdate += dt;
+        if (_timeSinceLastUpdate >= updateInterval)
+        {
+            _timeSinceLastUpdate = 0f;
+            RefreshDisplay();
+        }
+    }
+
+    // ── display logic ────────────────────────────────────────────────────────
+    void RefreshDisplay()
+    {
+        if (displayText == null) return;
+
+        // ── FPS ──────────────────────────────────────────────────────────────
+        float avgFrameTime = _accumulatedTime / _frameTimes.Count;   // seconds
+        float fps          = 1f / avgFrameTime;
+        float frameTimeMs  = avgFrameTime * 1000f;
+
+        // ── Input Lag estimate ───────────────────────────────────────────────
+        // Input lag ≈ time from physical input to pixel on screen.
+        // Best estimate without hardware: frame time + pipeline latency frames.
+        //
+        //  inputLag ≈ frameTime  +  (pipelineLatencyFrames × frameTime)
+        //           = frameTime × (1 + pipelineLatencyFrames)
+        //
+        // Add 8 ms as a rough USB / Bluetooth HID polling floor.
+        float hidPollMs     = 8f;   // ~1 frame @ 125 Hz polling; 1 ms @ 1000 Hz
+        float inputLagMs    = frameTimeMs * (1 + pipelineLatencyFrames) + hidPollMs;
+
+        // ── colour coding ────────────────────────────────────────────────────
+        string fpsColour = fps >= goodFPS   ? GREEN
+                         : fps >= warningFPS ? YELLOW
+                         : RED;
+
+        // ── format ───────────────────────────────────────────────────────────
+        displayText.text =
+            $"{fpsColour}{fps,5:F0} FPS{END}\n" +
+            $"Frame  {frameTimeMs,6:F2} ms\n" +
+            $"Lag  ≈ {inputLagMs,6:F2} ms";
+    }
+
+    // ── public helpers ───────────────────────────────────────────────────────
+
+    /// <summary>Toggle the overlay on / off (e.g. bind to F3).</summary>
+    public void Toggle() => displayText.gameObject.SetActive(
+                                !displayText.gameObject.activeSelf);
+}
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+fileFormatVersion: 2
+guid: 508ae74360f7e5249b100f7873b182f1