private const float kGoldenRatio = 1.61803398874989484820458683436f; //Esoteric factor used to decouple horizontal and vertical frequencies
public FlyNoiseSystem(FrameTime time, FlyData flyData, FlyNoiseData noiseData)
{
mFlyNoiseData = noiseData;
mRandom = new Random();
mTime = time;
mNoiseStateBuffer = new FlyNoiseState[flyData.MaxActiveFlies];
mPositionBuffer = new Position[flyData.MaxActiveFlies];
}
public void Update(EntityRegistry registry, EventSystem eventSystem)
{
int noNoiseCount = mNoNoiseSlice.Entity.Count;
for (int i = noNoiseCount - 1; i >= 0; --i)
{
float xModule = mRandom.GetRandomInRange(0f, kFrequencyNormalizer);
float yModule = mRandom.GetRandomInRange(0f, kFrequencyNormalizer);
float xPhase = mRandom.GetRandomInRange(0f, kFrequencyNormalizer);
float yPhase = mRandom.GetRandomInRange(0f, kFrequencyNormalizer);
FlyNoiseState initialState = new FlyNoiseState(xModule, yModule, xPhase, yPhase);
registry.AddComponent(mNoNoiseSlice.Entity[i], initialState);
}
int noiseCount = mNoisyFliesSlice.Entity.Count;
for (int i = 0; i < noiseCount; ++i)
{
float deltaTime = mTime.DeltaTime;
FlyNoiseState state = mNoisyFliesSlice.NoiseState[i];
float frequencyAdjust = kFrequencyNormalizer * mFlyNoiseData.ModulatorFrquency;
state.XModulePhase += (frequencyAdjust * deltaTime);
state.YModulePhase += (frequencyAdjust * kGoldenRatio * deltaTime);
frequencyAdjust = kFrequencyNormalizer * mFlyNoiseData.OscilationFrequency;
state.XOscilationPhase += (frequencyAdjust * deltaTime);
state.YOscilationPhase += (frequencyAdjust * kGoldenRatio * deltaTime);
mNoiseStateBuffer[i] = state;
}
//Compute buffer effects
for (int i = 0; i < noiseCount; ++i)
{
FlyNoiseState previousState = mNoisyFliesSlice.NoiseState[i];
FlyNoiseState currentState = mNoiseStateBuffer[i];
float xCurrent = (float)(mFlyNoiseData.OscilationModule * Math.Cos(currentState.XModulePhase) * Math.Cos(currentState.XOscilationPhase));
float yCurrent = (float)(mFlyNoiseData.OscilationModule * Math.Cos(currentState.YModulePhase) * Math.Cos(currentState.YOscilationPhase));
float xPrevious = (float)(mFlyNoiseData.OscilationModule * Math.Cos(previousState.XModulePhase) * Math.Cos(previousState.XOscilationPhase));
float yPrevious = (float)(mFlyNoiseData.OscilationModule * Math.Cos(previousState.YModulePhase) * Math.Cos(previousState.YOscilationPhase));
float xDelta = xCurrent - xPrevious;
float yDelta = yCurrent - yPrevious;
Vector2 currentPosition = mNoisyFliesSlice.Position[i].Value;
Vector2 newPosition = currentPosition + new Vector2(xDelta, yDelta);
mPositionBuffer[i] = new Position(newPosition);
}
//Write buffers back to components
for (int i = 0; i < noiseCount; ++i)
{
Entity fly = mNoisyFliesSlice.Entity[i];
registry.SetComponent(fly, mNoiseStateBuffer[i]);
registry.SetComponent(fly, mPositionBuffer[i]);
}
}