/// <summary>
/// Create a room to be simulated.
/// </summary>
/// <param name="size">The size of the room as a 3-dimensional vector.</param>
/// <param name="distanceAttenuation">The distance attenuation characteristics of the room.</param>
/// <param name="reflectionAttenuation">The reflection attenuation characteristics of the room.</param>
/// <param name="maxReflectionCount">The number of reflections to be simulated.</param>
public Room(Vector <double> size, DistanceAttenuation distanceAttenuation, ReflectionAttenuation reflectionAttenuation, int maxReflectionCount)
{
if (size == null)
{
throw new ArgumentNullException(nameof(size));
}
if (size.Count != 3)
{
throw new ArgumentException(nameof(size), "The length of the size vector must be 3.");
}
if (size.Any(value => value <= 0))
{
throw new ArgumentException(nameof(size), "All the values of the size vector must be positive.");
}
if (distanceAttenuation == null)
{
throw new ArgumentNullException(nameof(distanceAttenuation));
}
if (reflectionAttenuation == null)
{
throw new ArgumentNullException(nameof(reflectionAttenuation));
}
if (maxReflectionCount < 0)
{
throw new ArgumentException(nameof(maxReflectionCount), "The max reflection count must be greater than or equal to zero.");
}
this.size = size.Clone();
this.distanceAttenuation = distanceAttenuation;
this.reflectionAttenuation = reflectionAttenuation;
this.maxReflectionCount = maxReflectionCount;
}
public void GenerateImpulseResponse_CheckSignal()
{
var sampleRate = 16000;
var dftLength = 1024;
var delaySampleCount = 30;
var time = (double)delaySampleCount / sampleRate;
var distance = AcousticConstants.SoundSpeed * time;
var roomSize = DenseVector.OfArray(new double[] { distance, distance, distance });
var distanceAttenuation = new DistanceAttenuation(distance => 0.9);
var reflectionAttenuation = new ReflectionAttenuation(frequency => 0.7);
var room = new Room(roomSize, distanceAttenuation, reflectionAttenuation, 1);
var soundSource = new SoundSource(distance / 2, distance / 2, distance / 2);
var microphone = new Microphone(distance / 2, distance / 2, distance / 2);
var response = MirrorMethod.GenerateImpulseResponse(room, soundSource, microphone, sampleRate, dftLength);
Assert.AreEqual(dftLength / 2, response.Length);
for (var t = 0; t < response.Length; t++)
{
if (t == 0)
{
Assert.AreEqual(0.9, response[t], 1.0E-6);
}
else if (t == delaySampleCount)
{
Assert.AreEqual(6 * 0.9 * 0.7, response[t], 1.0E-6);
}
}
}
public void GenerateSoundRays_CheckRayProperties()
{
var roomSize = DenseVector.OfArray(new double[] { 2.0, 2.0, 2.0 });
var distanceAttenuation = new DistanceAttenuation(distance => 0.9);
var reflectionAttenuation = new ReflectionAttenuation(frequency => 0.7);
var room = new Room(roomSize, distanceAttenuation, reflectionAttenuation, 1);
var soundSource = new SoundSource(1.0, 1.0, 1.0);
var microphone = new Microphone(1.0, 1.0, 1.0);
var rays = MirrorMethod.GenerateSoundRays(room, soundSource, microphone).ToArray();
Assert.AreEqual(7, rays.Length);
foreach (var ray in rays)
{
if (ray.Distance < 1.0E-6)
{
Assert.AreEqual(0, ray.ReflectionCount);
}
else
{
Assert.AreEqual(2.0, ray.Distance, 1.0E-6);
Assert.AreEqual(1, ray.ReflectionCount);
}
}
}
public void GetMirroredPosition_Case3()
{
var roomSize = DenseVector.OfArray(new double[] { 3.0, 4.0, 2.0 });
var distanceAttenuation = new DistanceAttenuation(distance => 0.9);
var reflectionAttenuation = new ReflectionAttenuation(frequency => 0.7);
var room = new Room(roomSize, distanceAttenuation, reflectionAttenuation, 1);
var microphone = new Microphone(0.5, 1.0, 1.5);
var index = new MirroredRoomIndex(5, -2, -3);
var mirrored = MirrorMethod.GetMirroredPosition(room, microphone, index);
Assert.AreEqual(15.0 + 2.5, mirrored[0], 1.0E-9);
Assert.AreEqual(-8.0 + 1.0, mirrored[1], 1.0E-9);
Assert.AreEqual(-6.0 + 0.5, mirrored[2], 1.0E-9);
}
public void Constructor()
{
var roomSize = DenseVector.OfArray(new double[] { 3.0, 4.0, 2.0 });
var distanceAttenuation = new DistanceAttenuation(distance => 0.9);
var reflectionAttenuation = new ReflectionAttenuation(frequency => 0.7);
var room = new Room(roomSize, distanceAttenuation, reflectionAttenuation, 1);
Assert.IsTrue((roomSize - room.Size).L2Norm() < 1.0E-6);
Assert.AreEqual(distanceAttenuation(1), room.DistanceAttenuation(1));
Assert.AreEqual(distanceAttenuation(3), room.DistanceAttenuation(3));
Assert.AreEqual(reflectionAttenuation(0), room.ReflectionAttenuation(0));
Assert.AreEqual(reflectionAttenuation(1), room.ReflectionAttenuation(1));
Assert.AreEqual(reflectionAttenuation(3), room.ReflectionAttenuation(3));
Assert.AreEqual(1, room.MaxReflectionCount);
}
public void GenerateFrequencyDomainImpulseResponse_CheckDistanceAttenuation()
{
var sampleRate = 16000;
var dftLength = 1024;
var delaySampleCount = 30;
var time = (double)delaySampleCount / sampleRate;
var distance = AcousticConstants.SoundSpeed * time;
var roomSize = DenseVector.OfArray(new double[] { distance, distance, distance });
var distanceAttenuation = new DistanceAttenuation(distance => distance < 0.1 ? 3.1 : 2.3);
var reflectionAttenuation = new ReflectionAttenuation(frequency => 0.7);
var room = new Room(roomSize, distanceAttenuation, reflectionAttenuation, 1);
var soundSource = new SoundSource(distance / 2, distance / 2, distance / 2);
var microphone = new Microphone(distance / 2, distance / 2, distance / 2);
var response = MirrorMethod.GenerateFrequencyDomainImpulseResponse(room, soundSource, microphone, sampleRate, dftLength);
var timeDomainSignal = new Complex[dftLength];
timeDomainSignal[0] = response[0];
for (var w = 1; w < dftLength / 2; w++)
{
timeDomainSignal[w] = response[w];
timeDomainSignal[dftLength - w] = response[w].Conjugate();
}
timeDomainSignal[dftLength / 2] = response[dftLength / 2];
Fourier.Inverse(timeDomainSignal, FourierOptions.AsymmetricScaling);
for (var t = 0; t < dftLength; t++)
{
if (t == 0)
{
Assert.AreEqual(3.1, timeDomainSignal[t].Real, 1.0E-6);
Assert.AreEqual(0.0, timeDomainSignal[t].Imaginary, 1.0E-6);
}
else if (t == delaySampleCount)
{
Assert.AreEqual(6 * 2.3 * 0.7, timeDomainSignal[t].Real, 1.0E-6);
Assert.AreEqual(0.0, timeDomainSignal[t].Imaginary, 1.0E-6);
}
else
{
Assert.AreEqual(0.0, timeDomainSignal[t].Real, 1.0E-6);
Assert.AreEqual(0.0, timeDomainSignal[t].Imaginary, 1.0E-6);
}
}
}
public override string GetStepParameters()
{
var parameters = new List <string>();
parameters.Add(Name != null ? Name.ToStepValue() : "$");
parameters.Add(LightColour != null ? LightColour.ToStepValue() : "$");
parameters.Add(AmbientIntensity != null ? AmbientIntensity.ToStepValue() : "$");
parameters.Add(Intensity != null ? Intensity.ToStepValue() : "$");
parameters.Add(Position != null ? Position.ToStepValue() : "$");
parameters.Add(Radius != null ? Radius.ToStepValue() : "$");
parameters.Add(ConstantAttenuation != null ? ConstantAttenuation.ToStepValue() : "$");
parameters.Add(DistanceAttenuation != null ? DistanceAttenuation.ToStepValue() : "$");
parameters.Add(QuadricAttenuation != null ? QuadricAttenuation.ToStepValue() : "$");
return(string.Join(", ", parameters.ToArray()));
}
public void GenerateFrequencyDomainImpulseResponse_CheckReflectionAttenuation()
{
var sampleRate = 16000;
var dftLength = 1024;
var delaySampleCount = 30;
var time = (double)delaySampleCount / sampleRate;
var distance = AcousticConstants.SoundSpeed * time;
var cutOff = 4000;
var roomSize = DenseVector.OfArray(new double[] { distance, distance, distance });
var distanceAttenuation = new DistanceAttenuation(distance => distance < 1.0E-3 ? 0.0 : 0.9);
var reflectionAttenuation = new ReflectionAttenuation(frequency => frequency < cutOff ? 0.7 : 0.0);
var room = new Room(roomSize, distanceAttenuation, reflectionAttenuation, 1);
var soundSource = new SoundSource(distance / 2, distance / 2, distance / 2);
var microphone = new Microphone(distance / 2, distance / 2, distance / 2);
var response = MirrorMethod.GenerateFrequencyDomainImpulseResponse(room, soundSource, microphone, sampleRate, dftLength);
var validCount = 0;
for (var w = 0; w < response.Length; w++)
{
var frequency = (double)w / dftLength * sampleRate;
if (Math.Abs(frequency - cutOff) > 1)
{
if (frequency < cutOff)
{
Assert.IsTrue(response[w].Magnitude > 1.0E-3);
}
else
{
Assert.IsTrue(response[w].Magnitude < 1.0E-3);
}
validCount++;
}
}
Assert.IsTrue(validCount >= response.Length - 3);
}