Class SoundFontModulatorMath

Namespace

NAudio.Sampler

Assembly

NAudio.Sampler.dll

The SoundFont 2.04 modulator transform curves (§8.2.4) and source evaluation. A modulator's source controller value is normalised to [0, 1], shaped by one of four curves (linear / concave / convex / switch) in the direction and polarity selected by the source's D and P bits, and the result drives the modulator amount.

The spec gives the concave law only "as variations of" a logarithmic equation, so these use the standard 96 dB convention: the concave curve spans the SoundFont peak-attenuation range, which makes the implicit velocity→attenuation default modulator (§8.4.1) reproduce the familiar near-square-law velocity response. The bar is musical fidelity to the spec, not sample-identity with any particular synth (the fidelity bar stated in Docs/Architecture/SamplerDesign.md). Public and static so the transforms can be unit-tested directly.

public static class SoundFontModulatorMath

Inheritance

object

SoundFontModulatorMath

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Methods

Concave(double)

The SoundFont concave curve over [0, 1]: 0 at 0, rising slowly then steeply to 1 at 1. Output is clamped to [0, 1].

public static double Concave(double x)

Parameters

x double

Returns

double

Convex(double)

The SoundFont convex curve over [0, 1]: the concave curve with its start and end points reversed (§8.2.4). Output is clamped to [0, 1].

public static double Convex(double x)

Parameters

x double

Returns

double

Curve(SourceTypeEnum, double)

Applies one of the four source-type curves to a value in [0, 1].

public static double Curve(SourceTypeEnum type, double x)

Parameters

type SourceTypeEnum

x double

Returns

double

EvaluateSource(ModulatorType, double, double)

Evaluates a modulator source: normalises raw against max, applies the source's direction, curve and polarity, and returns the multiplier — [0, 1] for a unipolar source, [-1, 1] for a bipolar one. Bipolar concave/convex follow the §8.2.4 figures: zero at the controller centre, odd-symmetric to ±1 at the extremes (matching FluidSynth's reading of the spec).

public static double EvaluateSource(ModulatorType source, double raw, double max)

Parameters

source ModulatorType

raw double

max double

Returns

double