dasp_sample/
lib.rs

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1//! Use the [**Sample**](./trait.Sample.html) trait to remain generic over sample types, easily
2//! access sample type conversions, apply basic audio operations and more.
3//!
4//! The **Sample** trait is the core abstraction throughout dasp on which most other abstractions
5//! are based.
6
7#![cfg_attr(not(feature = "std"), no_std)]
8#![cfg_attr(not(feature = "std"), feature(core_intrinsics))]
9
10#[cfg(not(feature = "std"))]
11extern crate alloc;
12
13pub use conv::{Duplex, FromSample, ToSample};
14pub use types::{I24, I48, U24, U48};
15
16pub mod conv;
17mod ops;
18pub mod types;
19
20/// A trait for working generically across different **Sample** format types.
21///
22/// Provides methods for converting to and from any type that implements the
23/// [`FromSample`](./trait.FromSample.html) trait and provides methods for performing signal
24/// amplitude addition and multiplication.
25///
26/// # Example
27///
28/// ```rust
29/// use dasp_sample::{I24, Sample};
30///
31/// fn main() {
32///     assert_eq!((-1.0).to_sample::<u8>(), 0);
33///     assert_eq!(0.0.to_sample::<u8>(), 128);
34///     assert_eq!(0i32.to_sample::<u32>(), 2_147_483_648);
35///     assert_eq!(I24::new(0).unwrap(), Sample::from_sample(0.0));
36///     assert_eq!(0.0, Sample::EQUILIBRIUM);
37/// }
38/// ```
39pub trait Sample: Copy + Clone + PartialOrd + PartialEq {
40    /// When summing two samples of a signal together, it is necessary for both samples to be
41    /// represented in some signed format. This associated `Addition` type represents the format to
42    /// which `Self` should be converted for optimal `Addition` performance.
43    ///
44    /// For example, u32's optimal `Addition` type would be i32, u8's would be i8, f32's would be
45    /// f32, etc.
46    ///
47    /// Specifying this as an associated type allows us to automatically determine the optimal,
48    /// lossless Addition format type for summing any two unique `Sample` types together.
49    ///
50    /// As a user of the `sample` crate, you will never need to be concerned with this type unless
51    /// you are defining your own unique `Sample` type(s).
52    type Signed: SignedSample + Duplex<Self>;
53
54    /// When multiplying two samples of a signal together, it is necessary for both samples to be
55    /// represented in some signed, floating-point format. This associated `Multiplication` type
56    /// represents the format to which `Self` should be converted for optimal `Multiplication`
57    /// performance.
58    ///
59    /// For example, u32's optimal `Multiplication` type would be f32, u64's would be f64, i8's
60    /// would be f32, etc.
61    ///
62    /// Specifying this as an associated type allows us to automatically determine the optimal,
63    /// lossless Multiplication format type for multiplying any two unique `Sample` types together.
64    ///
65    /// As a user of the `sample` crate, you will never need to be concerned with this type unless
66    /// you are defining your own unique `Sample` type(s).
67    type Float: FloatSample + Duplex<Self>;
68
69    /// The equilibrium value for the wave that this `Sample` type represents. This is normally the
70    /// value that is equal distance from both the min and max ranges of the sample.
71    ///
72    /// # Example
73    ///
74    /// ```rust
75    /// use dasp_sample::Sample;
76    ///
77    /// fn main() {
78    ///     assert_eq!(0.0, f32::EQUILIBRIUM);
79    ///     assert_eq!(0, i32::EQUILIBRIUM);
80    ///     assert_eq!(128, u8::EQUILIBRIUM);
81    ///     assert_eq!(32_768_u16, Sample::EQUILIBRIUM);
82    /// }
83    /// ```
84    ///
85    /// **Note:** This will likely be changed to an "associated const" if the feature lands.
86    const EQUILIBRIUM: Self;
87
88    /// The multiplicative identity of the signal.
89    ///
90    /// In other words: A value which when used to scale/multiply the amplitude or frequency of a
91    /// signal, returns the same signal.
92    ///
93    /// This is useful as a default, non-affecting amplitude or frequency multiplier.
94    ///
95    /// # Example
96    ///
97    /// ```rust
98    /// use dasp_sample::{Sample, U48};
99    ///
100    /// fn main() {
101    ///     assert_eq!(1.0, f32::IDENTITY);
102    ///     assert_eq!(1.0, i8::IDENTITY);
103    ///     assert_eq!(1.0, u8::IDENTITY);
104    ///     assert_eq!(1.0, U48::IDENTITY);
105    /// }
106    /// ```
107    const IDENTITY: Self::Float = <Self::Float as FloatSample>::IDENTITY;
108
109    /// Convert `self` to any type that implements `FromSample<Self>`.
110    ///
111    /// Find more details on type-specific conversion ranges and caveats in the `conv` module.
112    ///
113    /// # Example
114    ///
115    /// ```rust
116    /// use dasp_sample::Sample;
117    ///
118    /// fn main() {
119    ///     assert_eq!(0.0.to_sample::<i32>(), 0);
120    ///     assert_eq!(0.0.to_sample::<u8>(), 128);
121    ///     assert_eq!((-1.0).to_sample::<u8>(), 0);
122    /// }
123    /// ```
124    #[inline]
125    fn to_sample<S>(self) -> S
126    where
127        Self: ToSample<S>,
128    {
129        self.to_sample_()
130    }
131
132    /// Create a `Self` from any type that implements `ToSample<Self>`.
133    ///
134    /// Find more details on type-specific conversion ranges and caveats in the `conv` module.
135    ///
136    /// # Example
137    ///
138    /// ```rust
139    /// use dasp_sample::{Sample, I24};
140    ///
141    /// fn main() {
142    ///     assert_eq!(f32::from_sample(128_u8), 0.0);
143    ///     assert_eq!(i8::from_sample(-1.0), -128);
144    ///     assert_eq!(I24::from_sample(0.0), I24::new(0).unwrap());
145    /// }
146    /// ```
147
148    #[inline]
149    fn from_sample<S>(s: S) -> Self
150    where
151        Self: FromSample<S>,
152    {
153        FromSample::from_sample_(s)
154    }
155
156    /// Converts `self` to the equivalent `Sample` in the associated `Signed` format.
157    ///
158    /// This is a simple wrapper around `Sample::to_sample` which may provide extra convenience in
159    /// some cases, particularly for assisting type inference.
160    ///
161    /// # Example
162    ///
163    /// ```rust
164    /// use dasp_sample::Sample;
165    ///
166    /// fn main() {
167    ///     assert_eq!(128_u8.to_signed_sample(), 0i8);
168    /// }
169    /// ```
170    fn to_signed_sample(self) -> Self::Signed {
171        self.to_sample()
172    }
173
174    /// Converts `self` to the equivalent `Sample` in the associated `Float` format.
175    ///
176    /// This is a simple wrapper around `Sample::to_sample` which may provide extra convenience in
177    /// some cases, particularly for assisting type inference.
178    ///
179    /// # Example
180    ///
181    /// ```rust
182    /// use dasp_sample::Sample;
183    ///
184    /// fn main() {
185    ///     assert_eq!(128_u8.to_float_sample(), 0.0);
186    /// }
187    /// ```
188    fn to_float_sample(self) -> Self::Float {
189        self.to_sample()
190    }
191
192    /// Adds (or "offsets") the amplitude of the `Sample` by the given signed amplitude.
193    ///
194    /// `Self` will be converted to `Self::Signed`, the addition will occur and then the result
195    /// will be converted back to `Self`. These conversions allow us to correctly handle the
196    /// addition of unsigned signal formats.
197    ///
198    /// # Example
199    ///
200    /// ```rust
201    /// use dasp_sample::Sample;
202    ///
203    /// fn main() {
204    ///     assert_eq!(0.25.add_amp(0.5), 0.75);
205    ///     assert_eq!(192u8.add_amp(-128), 64);
206    /// }
207    /// ```
208    #[inline]
209    fn add_amp(self, amp: Self::Signed) -> Self {
210        let self_s = self.to_signed_sample();
211        (self_s + amp).to_sample()
212    }
213
214    /// Multiplies (or "scales") the amplitude of the `Sample` by the given float amplitude.
215    ///
216    /// - `amp` > 1.0 amplifies the sample.
217    /// - `amp` < 1.0 attenuates the sample.
218    /// - `amp` == 1.0 yields the same sample.
219    /// - `amp` == 0.0 yields the `Sample::EQUILIBRIUM`.
220    ///
221    /// `Self` will be converted to `Self::Float`, the multiplication will occur and then the
222    /// result will be converted back to `Self`. These conversions allow us to correctly handle the
223    /// multiplication of integral signal formats.
224    ///
225    /// # Example
226    ///
227    /// ```rust
228    /// use dasp_sample::Sample;
229    ///
230    /// fn main() {
231    ///     assert_eq!(64_i8.mul_amp(0.5), 32);
232    ///     assert_eq!(0.5.mul_amp(-2.0), -1.0);
233    ///     assert_eq!(64_u8.mul_amp(0.0), 128);
234    /// }
235    /// ```
236    #[inline]
237    fn mul_amp(self, amp: Self::Float) -> Self {
238        let self_f = self.to_float_sample();
239        (self_f * amp).to_sample()
240    }
241}
242
243/// A macro used to simplify the implementation of `Sample`.
244macro_rules! impl_sample {
245    ($($T:ty:
246       Signed: $Addition:ty,
247       Float: $Modulation:ty,
248       EQUILIBRIUM: $EQUILIBRIUM:expr),*) =>
249    {
250        $(
251            impl Sample for $T {
252                type Signed = $Addition;
253                type Float = $Modulation;
254                const EQUILIBRIUM: Self = $EQUILIBRIUM;
255            }
256        )*
257    }
258}
259
260// Expands to `Sample` implementations for all of the following types.
261impl_sample! {
262    i8:  Signed: i8,  Float: f32, EQUILIBRIUM: 0,
263    i16: Signed: i16, Float: f32, EQUILIBRIUM: 0,
264    I24: Signed: I24, Float: f32, EQUILIBRIUM: types::i24::EQUILIBRIUM,
265    i32: Signed: i32, Float: f32, EQUILIBRIUM: 0,
266    I48: Signed: I48, Float: f64, EQUILIBRIUM: types::i48::EQUILIBRIUM,
267    i64: Signed: i64, Float: f64, EQUILIBRIUM: 0,
268    u8:  Signed: i8,  Float: f32, EQUILIBRIUM: 128,
269    u16: Signed: i16, Float: f32, EQUILIBRIUM: 32_768,
270    U24: Signed: i32, Float: f32, EQUILIBRIUM: types::u24::EQUILIBRIUM,
271    u32: Signed: i32, Float: f32, EQUILIBRIUM: 2_147_483_648,
272    U48: Signed: i64, Float: f64, EQUILIBRIUM: types::u48::EQUILIBRIUM,
273    u64: Signed: i64, Float: f64, EQUILIBRIUM: 9_223_372_036_854_775_808,
274    f32: Signed: f32, Float: f32, EQUILIBRIUM: 0.0,
275    f64: Signed: f64, Float: f64, EQUILIBRIUM: 0.0
276}
277
278/// Integral and floating-point **Sample** format types whose equilibrium is at 0.
279///
280/// **Sample**s often need to be converted to some mutual **SignedSample** type for signal
281/// addition.
282pub trait SignedSample:
283    Sample<Signed = Self>
284    + core::ops::Add<Output = Self>
285    + core::ops::Sub<Output = Self>
286    + core::ops::Neg<Output = Self>
287{
288}
289macro_rules! impl_signed_sample { ($($T:ty)*) => { $( impl SignedSample for $T {} )* } }
290impl_signed_sample!(i8 i16 I24 i32 I48 i64 f32 f64);
291
292/// Sample format types represented as floating point numbers.
293///
294/// **Sample**s often need to be converted to some mutual **FloatSample** type for signal scaling
295/// and modulation.
296pub trait FloatSample:
297    Sample<Signed = Self, Float = Self>
298    + SignedSample
299    + core::ops::Mul<Output = Self>
300    + core::ops::Div<Output = Self>
301    + Duplex<f32>
302    + Duplex<f64>
303{
304    /// Represents the multiplicative identity of the floating point signal.
305    const IDENTITY: Self;
306    /// Calculate the square root of `Self`.
307    fn sample_sqrt(self) -> Self;
308}
309
310impl FloatSample for f32 {
311    const IDENTITY: Self = 1.0;
312    #[inline]
313    fn sample_sqrt(self) -> Self {
314        ops::f32::sqrt(self)
315    }
316}
317
318impl FloatSample for f64 {
319    const IDENTITY: Self = 1.0;
320    #[inline]
321    fn sample_sqrt(self) -> Self {
322        ops::f64::sqrt(self)
323    }
324}
dasp_sample/lib.rs

dasp_sample/
lib.rs
