major rework

Car simulation/Audio/EngineSound.cs

@@ -0,0 +1,110 @@
+using SFML.Audio;
+using SFML.System;
+using System;
+
+namespace Car_simulation.Audio
+{
+    public class EngineSound : SoundStream
+    {
+        private const uint SAMPLE_RATE = 44100;
+        private const ushort CHANNELS = 2;
+        private const float BUFFER_DURATION = 0.01f;
+
+        private volatile float _currentRPM = 800f;
+        private volatile float _currentThrottle = 0f;
+        private float _volume = 0.3f;
+        private bool _isPlaying = false;
+
+        private readonly int _cylinders = 4;
+        private readonly Random _rand = new Random();
+
+        // Engine harmonics
+        private readonly float[] _harmonicMultiples = { 1f, 2f, 3f, 4f };
+        private readonly float[] _harmonicAmps = { 0.3f, 0.6f, 0.4f, 0.2f };
+        private readonly float[] _harmonicPhases = new float[4];
+
+        public EngineSound()
+        {
+            Initialize(CHANNELS, SAMPLE_RATE);
+            for (int i = 0; i < _harmonicPhases.Length; i++)
+                _harmonicPhases[i] = (float)(_rand.NextDouble() * 2 * Math.PI);
+        }
+
+        public void SetEngineState(float rpm, float throttle)
+        {
+            _currentRPM = rpm;
+            _currentThrottle = throttle;
+            _volume = 0.1f + 0.4f * throttle;
+        }
+
+        public void StartSound()
+        {
+            if (!_isPlaying)
+            {
+                Play();
+                _isPlaying = true;
+            }
+        }
+
+        public void StopSound()
+        {
+            if (_isPlaying)
+            {
+                Stop();
+                _isPlaying = false;
+            }
+        }
+
+        protected override bool OnGetData(out short[] samples)
+        {
+            int sampleCount = (int)(SAMPLE_RATE * BUFFER_DURATION) * CHANNELS;
+            samples = new short[sampleCount];
+
+            for (int i = 0; i < sampleCount; i += 2)
+            {
+                float sampleValue = 0f;
+
+                // Read RPM per sample (instant)
+                float rpm = _currentRPM;
+                float throttle = _currentThrottle;
+
+                // Base frequency for 4-cylinder, 4-stroke
+                float baseFreq = (rpm / 60f) * (_cylinders / 2f);
+
+                // Sum harmonics
+                for (int h = 0; h < _harmonicMultiples.Length; h++)
+                {
+                    float freq = baseFreq * _harmonicMultiples[h];
+                    float phaseInc = freq * 2f * MathF.PI / SAMPLE_RATE;
+
+                    // Slight jitter for realism
+                    float jitter = 0.001f * ((float)_rand.NextDouble() - 0.5f);
+                    _harmonicPhases[h] += phaseInc + jitter;
+
+                    if (_harmonicPhases[h] > 2f * MathF.PI)
+                        _harmonicPhases[h] -= 2f * MathF.PI;
+
+                    sampleValue += MathF.Sin(_harmonicPhases[h]) * _harmonicAmps[h];
+                }
+
+                // Add noise for roughness
+                sampleValue += ((float)_rand.NextDouble() * 2f - 1f) * 0.02f * throttle;
+
+                // Volume and clamp
+                sampleValue = Math.Clamp(sampleValue * _volume, -1f, 1f);
+                short finalSample = (short)(sampleValue * 32767);
+
+                samples[i] = finalSample;
+                samples[i + 1] = finalSample;
+            }
+
+            return true;
+        }
+
+        protected override void OnSeek(Time timeOffset)
+        {
+            for (int i = 0; i < _harmonicPhases.Length; i++)
+                _harmonicPhases[i] = (float)(_rand.NextDouble() * 2 * Math.PI);
+        }
+    }
+}