Enum Volume 

pub enum Volume {
    Linear(f32),
    Decibels(f32),
}

A Volume represents an audio source’s volume level.

To create a new Volume from a linear scale value, use Volume::Linear.

To create a new Volume from decibels, use Volume::Decibels.

Variants

Linear(f32)

Create a new Volume from the given volume in the linear scale.

In a linear scale, the value 1.0 represents the “normal” volume, meaning the audio is played at its original level. Values greater than 1.0 increase the volume, while values between 0.0 and 1.0 decrease the volume. A value of 0.0 effectively mutes the audio.

Examples

let volume = Volume::Linear(0.5);
assert_eq!(volume.to_linear(), 0.5);
assert!(ops::abs(volume.to_decibels() - -6.0206) < EPSILON);

let volume = Volume::Linear(0.0);
assert_eq!(volume.to_linear(), 0.0);
assert_eq!(volume.to_decibels(), f32::NEG_INFINITY);

let volume = Volume::Linear(1.0);
assert_eq!(volume.to_linear(), 1.0);
assert!(ops::abs(volume.to_decibels() - 0.0) < EPSILON);

Decibels(f32)

Create a new Volume from the given volume in decibels.

In a decibel scale, the value 0.0 represents the “normal” volume, meaning the audio is played at its original level. Values greater than 0.0 increase the volume, while values less than 0.0 decrease the volume. A value of f32::NEG_INFINITY decibels effectively mutes the audio.

Examples

let volume = Volume::Decibels(-5.998);
assert!(ops::abs(volume.to_linear() - 0.5) < EPSILON);

let volume = Volume::Decibels(f32::NEG_INFINITY);
assert_eq!(volume.to_linear(), 0.0);

let volume = Volume::Decibels(0.0);
assert_eq!(volume.to_linear(), 1.0);

let volume = Volume::Decibels(20.0);
assert_eq!(volume.to_linear(), 10.0);

Implementations

impl Volume

pub const SILENT: Volume

The silent volume. Also known as “off” or “muted”.

pub fn to_linear(&self) -> f32

Returns the volume in linear scale as a float.

pub fn to_decibels(&self) -> f32

Returns the volume in decibels as a float.

If the volume is silent / off / muted, i.e., its underlying linear scale is 0.0, this method returns negative infinity.

pub fn increase_by_percentage(&self, percentage: f32) -> Volume

Increases the volume by the specified percentage.

This method works in the linear domain, where a 100% increase means doubling the volume (equivalent to +6.02dB).

Arguments

• percentage - The percentage to increase (50.0 means 50% increase)

Examples

use bevy_audio::Volume;

let volume = Volume::Linear(1.0);
let increased = volume.increase_by_percentage(100.0);
assert_eq!(increased.to_linear(), 2.0);

Examples found in repository

examples/audio/audio_control.rs (line 108)

fn volume(
    keyboard_input: Res<ButtonInput<KeyCode>>,
    mut music_controller: Query<&mut AudioSink, With<MyMusic>>,
) {
    let Ok(mut sink) = music_controller.single_mut() else {
        return;
    };

    if keyboard_input.just_pressed(KeyCode::Equal) {
        let current_volume = sink.volume();
        sink.set_volume(current_volume.increase_by_percentage(10.0));
    } else if keyboard_input.just_pressed(KeyCode::Minus) {
        let current_volume = sink.volume();
        sink.set_volume(current_volume.increase_by_percentage(-10.0));
    }
}

pub fn decrease_by_percentage(&self, percentage: f32) -> Volume

Decreases the volume by the specified percentage.

This method works in the linear domain, where a 50% decrease means halving the volume (equivalent to -6.02dB).

Arguments

• percentage - The percentage to decrease (50.0 means 50% decrease)

Examples

use bevy_audio::Volume;

let volume = Volume::Linear(1.0);
let decreased = volume.decrease_by_percentage(50.0);
assert_eq!(decreased.to_linear(), 0.5);

pub fn scale_to_factor(&self, factor: f32) -> Volume

Scales the volume to a specific linear factor relative to the current volume.

This is different from adjust_by_linear as it sets the volume to be exactly the factor times the original volume, rather than applying the factor to the current volume.

Arguments

• factor - The scaling factor (2.0 = twice as loud, 0.5 = half as loud)

Examples

use bevy_audio::Volume;

let volume = Volume::Linear(0.8);
let scaled = volume.scale_to_factor(1.25);
assert_eq!(scaled.to_linear(), 1.0);

pub fn fade_towards(&self, target: Volume, factor: f32) -> Volume

Creates a fade effect by interpolating between current volume and target volume.

This method performs linear interpolation in the linear domain, which provides a more natural-sounding fade effect.

Arguments

• target - The target volume to fade towards
• factor - The interpolation factor (0.0 = current volume, 1.0 = target volume)

Examples

use bevy_audio::Volume;

let current = Volume::Linear(1.0);
let target = Volume::Linear(0.0);
let faded = current.fade_towards(target, 0.5);
assert_eq!(faded.to_linear(), 0.5);

Examples found in repository

examples/audio/soundtrack.rs (line 108)

fn fade_in(
    mut commands: Commands,
    mut audio_sink: Query<(&mut AudioSink, Entity), With<FadeIn>>,
    timer: Res<GameStateTimer>,
) {
    for (mut audio, entity) in audio_sink.iter_mut() {
        audio.set_volume(
            Volume::SILENT.fade_towards(Volume::Linear(1.0), timer.0.elapsed_secs() / FADE_TIME),
        );
        if timer.0.elapsed_secs() >= FADE_TIME {
            audio.set_volume(Volume::Linear(1.0));
            commands.entity(entity).remove::<FadeIn>();
        }
    }
}

// Fades out the audio of entities that has the FadeOut component. Despawns the entities once audio
// volume reaches zero.
fn fade_out(
    mut commands: Commands,
    mut audio_sink: Query<(&mut AudioSink, Entity), With<FadeOut>>,
    timer: Res<GameStateTimer>,
) {
    for (mut audio, entity) in audio_sink.iter_mut() {
        audio.set_volume(
            Volume::Linear(1.0).fade_towards(Volume::SILENT, timer.0.elapsed_secs() / FADE_TIME),
        );
        if timer.0.elapsed_secs() >= FADE_TIME {
            commands.entity(entity).despawn();
        }
    }
}

Trait Implementations

impl Clone for Volume

fn clone(&self) -> Volume

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Volume

impl Debug for Volume

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

Formats the value using the given formatter.

impl Default for Volume

fn default() -> Volume

Returns the “default value” for a type.

impl Div for Volume

type Output = Volume

The resulting type after applying the / operator.

fn div(self, rhs: Volume) -> Volume

Performs the / operation.

impl DivAssign for Volume

fn div_assign(&mut self, rhs: Volume)

Performs the /= operation.

impl Enum for Volume

fn field(&self, __name_param: &str) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field (in the current variant) with the given name.

fn field_at( &self, __index_param: usize, ) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field (in the current variant) at the given index.

fn field_mut( &mut self, __name_param: &str, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field (in the current variant) with the given name.

fn field_at_mut( &mut self, __index_param: usize, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field (in the current variant) at the given index.

fn index_of(&self, __name_param: &str) -> Option<usize>

Returns the index of the field (in the current variant) with the given name.

fn name_at(&self, __index_param: usize) -> Option<&str>

Returns the name of the field (in the current variant) with the given index.

fn iter_fields(&self) -> VariantFieldIter<'_>

Returns an iterator over the values of the current variant’s fields.

fn field_len(&self) -> usize

Returns the number of fields in the current variant.

fn variant_name(&self) -> &str

The name of the current variant.

fn variant_index(&self) -> usize

The index of the current variant.

fn variant_type(&self) -> VariantType

The type of the current variant.

fn to_dynamic_enum(&self) -> DynamicEnum

Creates a new DynamicEnum from this enum.

fn is_variant(&self, variant_type: VariantType) -> bool

Returns true if the current variant’s type matches the given one.

fn variant_path(&self) -> String

Returns the full path to the current variant.

fn get_represented_enum_info(&self) -> Option<&'static EnumInfo>

Will return None if TypeInfo is not available.

impl From<Volume> for GlobalVolume

fn from(volume: Volume) -> GlobalVolume

Converts to this type from the input type.

impl FromArg for Volume

type This<'from_arg> = Volume

The type to convert into.

fn from_arg(arg: Arg<'_>) -> Result<<Volume as FromArg>::This<'_>, ArgError>

Creates an item from an argument.

impl FromReflect for Volume

fn from_reflect(__param0: &(dyn PartialReflect + 'static)) -> Option<Volume>

Constructs a concrete instance of Self from a reflected value.

fn take_from_reflect( reflect: Box<dyn PartialReflect>, ) -> Result<Self, Box<dyn PartialReflect>>

Attempts to downcast the given value to Self using, constructing the value using from_reflect if that fails.

impl GetOwnership for Volume

fn ownership() -> Ownership

Returns the ownership of Self.

impl GetTypeRegistration for Volume

fn get_type_registration() -> TypeRegistration

Returns the default TypeRegistration for this type.

fn register_type_dependencies(registry: &mut TypeRegistry)

Registers other types needed by this type.

impl IntoReturn for Volume

fn into_return<'into_return>(self) -> Return<'into_return>

where Volume: 'into_return,

Converts Self into a Return value.

impl Mul for Volume

type Output = Volume

The resulting type after applying the * operator.

fn mul(self, rhs: Volume) -> Volume

Performs the * operation.

impl MulAssign for Volume

fn mul_assign(&mut self, rhs: Volume)

Performs the *= operation.

impl PartialEq for Volume

fn eq(&self, other: &Volume) -> 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 PartialOrd for Volume

fn partial_cmp(&self, other: &Volume) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialReflect for Volume

fn get_represented_type_info(&self) -> Option<&'static TypeInfo>

Returns the TypeInfo of the type represented by this value.

fn try_apply( &mut self, __value_param: &(dyn PartialReflect + 'static), ) -> Result<(), ApplyError>

Tries to apply a reflected value to this value.

fn reflect_kind(&self) -> ReflectKind

Returns a zero-sized enumeration of “kinds” of type.

fn reflect_ref(&self) -> ReflectRef<'_>

Returns an immutable enumeration of “kinds” of type.

fn reflect_mut(&mut self) -> ReflectMut<'_>

Returns a mutable enumeration of “kinds” of type.

fn reflect_owned(self: Box<Volume>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn try_into_reflect( self: Box<Volume>, ) -> Result<Box<dyn Reflect>, Box<dyn PartialReflect>>

Attempts to cast this type to a boxed, fully-reflected value.

fn try_as_reflect(&self) -> Option<&(dyn Reflect + 'static)>

Attempts to cast this type to a fully-reflected value.

fn try_as_reflect_mut(&mut self) -> Option<&mut (dyn Reflect + 'static)>

Attempts to cast this type to a mutable, fully-reflected value.

fn into_partial_reflect(self: Box<Volume>) -> Box<dyn PartialReflect>

Casts this type to a boxed, reflected value.

fn as_partial_reflect(&self) -> &(dyn PartialReflect + 'static)

Casts this type to a reflected value.

fn as_partial_reflect_mut(&mut self) -> &mut (dyn PartialReflect + 'static)

Casts this type to a mutable, reflected value.

fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type).

fn reflect_partial_eq( &self, value: &(dyn PartialReflect + 'static), ) -> Option<bool>

Returns a “partial equality” comparison result.

fn reflect_partial_cmp( &self, value: &(dyn PartialReflect + 'static), ) -> Option<Ordering>

Returns a “partial comparison” result.

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

Debug formatter for the value.

fn reflect_clone(&self) -> Result<Box<dyn Reflect>, ReflectCloneError>

Attempts to clone Self using reflection.

fn apply(&mut self, value: &(dyn PartialReflect + 'static))

Applies a reflected value to this value.

fn to_dynamic(&self) -> Box<dyn PartialReflect>

Converts this reflected value into its dynamic representation based on its kind.

fn reflect_clone_and_take<T>(&self) -> Result<T, ReflectCloneError>

where T: 'static, Self: Sized + TypePath,

For a type implementing PartialReflect, combines reflect_clone and take in a useful fashion, automatically constructing an appropriate ReflectCloneError if the downcast fails.

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type.

impl Reflect for Volume

fn into_any(self: Box<Volume>) -> Box<dyn Any>

Returns the value as a Box<dyn Any>.

fn as_any(&self) -> &(dyn Any + 'static)

Returns the value as a &dyn Any.

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Returns the value as a &mut dyn Any.

fn into_reflect(self: Box<Volume>) -> Box<dyn Reflect>

Casts this type to a boxed, fully-reflected value.

fn as_reflect(&self) -> &(dyn Reflect + 'static)

Casts this type to a fully-reflected value.

fn as_reflect_mut(&mut self) -> &mut (dyn Reflect + 'static)

Casts this type to a mutable, fully-reflected value.

fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>>

Performs a type-checked assignment of a reflected value to this value.

impl TypePath for Volume

fn type_path() -> &'static str

Returns the fully qualified path of the underlying type.

fn short_type_path() -> &'static str

Returns a short, pretty-print enabled path to the type.

fn type_ident() -> Option<&'static str>

Returns the name of the type, or None if it is anonymous.

fn crate_name() -> Option<&'static str>

Returns the name of the crate the type is in, or None if it is anonymous.

fn module_path() -> Option<&'static str>

Returns the path to the module the type is in, or None if it is anonymous.

impl Typed for Volume

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.