Enum ParameterUnit 

#[repr(u32)]
pub enum ParameterUnit {
    Generic = 0,
    Indexed = 1,
    Boolean = 2,
    Percent = 3,
    Seconds = 4,
    SampleFrames = 5,
    Phase = 6,
    Rate = 7,
    Hertz = 8,
    Cents = 9,
    RelativeSemiTones = 10,
    MidiNoteNumber = 11,
    MidiController = 12,
    Decibels = 13,
    LinearGain = 14,
    Degrees = 15,
    EqualPowerCrossfade = 16,
    MixerFaderCurve1 = 17,
    Pan = 18,
    Meters = 19,
    AbsoluteCents = 20,
    Octaves = 21,
    Bpm = 22,
    Beats = 23,
    Milliseconds = 24,
    Ratio = 25,
    CustomUnit = 26,
}

AudioUnitParameterUnit values for parameter type hints.

These values tell AU hosts what visual control to render for a parameter:

• Boolean → Checkbox
• Indexed → Dropdown menu
• Decibels, Hertz, etc. → Slider with appropriate unit display

The values match Apple’s AudioUnitParameterUnit enum from AudioToolbox/AudioUnitProperties.h for direct FFI compatibility.

Example

// Most constructors set this automatically:
let gain = FloatParameter::db("Gain", 0.0, -60.0..=12.0);  // → Decibels
let enabled = BoolParameter::new("Enabled", true);         // → Boolean

// Override if needed:
let custom = FloatParameter::new("Custom", 0.5, 0.0..=1.0)
    .with_unit(ParameterUnit::Percent);

Variants

Generic = 0

Generic parameter (default slider)

Indexed = 1

Indexed parameter (dropdown menu for enums)

Boolean = 2

Boolean parameter (checkbox)

Percent = 3

Percentage (0-100%)

Seconds = 4

Time in seconds

SampleFrames = 5

Sample frames

Phase = 6

Phase (0-360 degrees or 0-1)

Rate = 7

Rate multiplier

Hertz = 8

Frequency in Hertz

Cents = 9

Pitch in cents

RelativeSemiTones = 10

Relative pitch in semitones

MidiNoteNumber = 11

MIDI note number (0-127)

MidiController = 12

MIDI controller value (0-127)

Decibels = 13

Level in decibels

LinearGain = 14

Linear gain (0.0-1.0+)

Degrees = 15

Angle in degrees

EqualPowerCrossfade = 16

Equal power crossfade

MixerFaderCurve1 = 17

Mixer fader curve 1

Pan = 18

Stereo pan (-1 to +1)

Meters = 19

Distance in meters

AbsoluteCents = 20

Absolute pitch in cents

Octaves = 21

Pitch in octaves

Bpm = 22

Tempo in beats per minute

Beats = 23

Musical beats

Milliseconds = 24

Time in milliseconds

Ratio = 25

Ratio (e.g., compression ratio)

CustomUnit = 26

Custom unit (use units string for display)

Trait Implementations

impl Clone for ParameterUnit

fn clone(&self) -> ParameterUnit

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ParameterUnit

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ParameterUnit

fn default() -> ParameterUnit

Returns the “default value” for a type.

impl PartialEq for ParameterUnit

fn eq(&self, other: &ParameterUnit) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ParameterUnit

impl Eq for ParameterUnit

impl StructuralPartialEq for ParameterUnit