Attempting to generate sound, and set cells automatically

Program.cs

@@ -2,7 +2,8 @@
 using SFML.Window;
 using SFML.System;
 using System.Diagnostics;
-using FluidSim.Core;
+using FluidSim.Scenarios;
+using FluidSim.Audio;
 
 namespace FluidSim;
 
@@ -10,6 +11,8 @@ public class Program
 {
     private const int SampleRate = 44100;
     private static volatile bool running = true;
+    // Global step counter – incremented every simulation step
+    private static long stepCount = 0;
 
     public static void Main()
     {
@@ -22,47 +25,71 @@ public class Program
         soundEngine.Volume = 70;
         soundEngine.Start();
 
-        double lastAudioTime = 0.0;
         var stopwatch = Stopwatch.StartNew();
 
-        int warmupSamples = SampleRate / 2;
+        // --- Warmup: fill audio buffer with silence ---
+        int warmupSamples = SampleRate / 2;                // 0.5 s
         float[] warmup = new float[warmupSamples];
         for (int i = 0; i < warmupSamples; i++)
             warmup[i] = 0;
-
         soundEngine.WriteSamples(warmup, warmupSamples);
-        lastAudioTime = stopwatch.Elapsed.TotalSeconds;
+
+        // Reset timer after warmup – this is the “real‑time zero”
+        stopwatch.Restart();
+        stepCount = 0;                                     // simulation steps start now
+
+        // --- Initialise the simulation scenario ---
+        Simulation.Initialize(SampleRate);
 
         const int chunkSize = 2048;
         float[] buffer = new float[chunkSize];
 
-        Simulation.Initialize(SampleRate);
+        double lastLogTime = 0.0;                         // for periodic speed printout
 
         while (window.IsOpen)
         {
             window.DispatchEvents();
 
+            // --- Compute how many audio samples are needed since last frame ---
             double currentTime = stopwatch.Elapsed.TotalSeconds;
-            double elapsed = currentTime - lastAudioTime;
-            int samplesNeeded = (int)(elapsed * SampleRate);
+            double elapsed = currentTime;                  // since stopwatch was reset
+            int samplesNeeded = (int)(elapsed * SampleRate) - (int)(stepCount);
+            // (stepCount is total generated samples, so we just need the remainder)
 
+            // --- Generate the required number of simulation steps ---
             while (samplesNeeded > 0 && running)
             {
                 int toGenerate = Math.Min(samplesNeeded, chunkSize);
                 for (int i = 0; i < toGenerate; i++)
                 {
                     buffer[i] = Simulation.Process();
+                    stepCount++;
                 }
                 soundEngine.WriteSamples(buffer, toGenerate);
                 samplesNeeded -= toGenerate;
             }
 
-            lastAudioTime = currentTime;
+            // --- Display speed ---
+            double simTime = stepCount / (double)SampleRate;
+            double wallTime = stopwatch.Elapsed.TotalSeconds;
+            double speed = (wallTime > 0) ? simTime / wallTime : 0.0;
 
+            // Update window title with instant speed
+            window.SetTitle($"FluidSim | Speed: {speed:F3}× | Steps: {stepCount}");
+
+            // Console log once per second
+            if (wallTime - lastLogTime >= 1.0)
+            {
+                Console.WriteLine($"Speed: {speed:F3}×  ({stepCount} steps, {wallTime:F2}s wall)");
+                lastLogTime = wallTime;
+            }
+
+            // --- Rendering (placeholder) ---
             window.Clear(Color.Black);
             window.Display();
         }
 
+        // --- Cleanup ---
         soundEngine.Dispose();
         window.Dispose();
     }