add consts module

README.md

@@ -48,6 +48,7 @@ numeric primitives are implemented. That is, you can use [`From`] or
   * The [`saturating_neg`] method was added to all fixed-point
     numbers, and the [`saturating_abs`] method was added to signed
     fixed-point numbers.
+  * The [`consts`] module was added.
 
 #### Incompatible changes
 
@@ -64,6 +65,7 @@ numeric primitives are implemented. That is, you can use [`From`] or
 [`LossyFrom`]: https://docs.rs/fixed/0.3.4/fixed/traits/trait.LossyFrom.html
 [`LossyInto`]: https://docs.rs/fixed/0.3.4/fixed/traits/trait.LossyInto.html
 [`ToFixed`]: https://docs.rs/fixed/0.3.4/fixed/traits/trait.ToFixed.html
+[`consts`]: https://docs.rs/fixed/0.3.4/fixed/consts/index.html
 [`saturating_abs`]: https://docs.rs/fixed/0.3.4/fixed/struct.FixedI32.html#method.saturating_abs
 [`saturating_neg`]: https://docs.rs/fixed/0.3.4/fixed/struct.FixedI32.html#method.saturating_neg
 [`traits`]: https://docs.rs/fixed/0.3.4/fixed/traits/index.html

RELEASES.md

@@ -15,9 +15,14 @@ Version 0.4.0 (unreleased)
   * The `saturating_neg` method was added to all fixed-point numbers,
     and the `saturating_abs` method was added to signed fixed-point
     numbers.
-  * Incompatible change: The sealed traits `Int` and `Float` now have
-    no provided methods; the methods in the old implementation are now
-    provided by `FromFixed` and `ToFixed`.
+  * The `consts` module was added.
+
+Incompatible changes
+--------------------
+
+  * The sealed traits `Int` and `Float` now have no provided methods;
+    the methods in the old implementation are now provided by
+    `FromFixed` and `ToFixed`.
 
 Version 0.3.3 (2019-06-27)
 ==========================

src/consts.rs

@@ -0,0 +1,190 @@
+// Copyright © 2018–2019 Trevor Spiteri
+
+// This library is free software: you can redistribute it and/or
+// modify it under the terms of either
+//
+//   * the Apache License, Version 2.0 or
+//   * the MIT License
+//
+// at your option.
+//
+// You should have recieved copies of the Apache License and the MIT
+// License along with the library. If not, see
+// <https://www.apache.org/licenses/LICENSE-2.0> and
+// <https://opensource.org/licenses/MIT>.
+
+/*!
+This module contains constants.
+
+The constants have the maximum precision possible for a fixed-point
+number, and are rounded down at that precision.
+
+# Examples
+
+```rust
+let pi: fixed::types::I8F8 = fixed::consts::PI.to_fixed();
+println!("π with eight binary places is {:b}", pi);
+assert_eq!(format!("{:b}", pi), "11.00100100");
+```
+*/
+
+use crate::{
+    frac::{U126, U127, U128},
+    FixedU128,
+};
+use core::marker::PhantomData;
+
+/// π = 3.141…
+// PI = 3.141592653589793238462643383279502884197
+pub const PI: FixedU128<U126> = FixedU128 {
+    bits: 0xC90F_DAA2_2168_C234_C4C6_628B_80DC_1CD1,
+    phantom: PhantomData,
+};
+
+/// π/2 = 1.570…
+// FRAC_PI_2 = 1.570796326794896619231321691639751442099
+pub const FRAC_PI_2: FixedU128<U127> = FixedU128 {
+    bits: 0xC90F_DAA2_2168_C234_C4C6_628B_80DC_1CD1,
+    phantom: PhantomData,
+};
+
+/// π/3 = 1.047…
+// FRAC_PI_3 = 1.047197551196597746154214461093167628066
+pub const FRAC_PI_3: FixedU128<U127> = FixedU128 {
+    bits: 0x860A_91C1_6B9B_2C23_2DD9_9707_AB3D_688B,
+    phantom: PhantomData,
+};
+
+/// π/4 = 0.7853…
+// FRAC_PI_4 = 0.7853981633974483096156608458198757210493
+pub const FRAC_PI_4: FixedU128<U128> = FixedU128 {
+    bits: 0xC90F_DAA2_2168_C234_C4C6_628B_80DC_1CD1,
+    phantom: PhantomData,
+};
+
+/// π/6 = 0.5235…
+// FRAC_PI_6 = 0.5235987755982988730771072305465838140329
+pub const FRAC_PI_6: FixedU128<U128> = FixedU128 {
+    bits: 0x860A_91C1_6B9B_2C23_2DD9_9707_AB3D_688B,
+    phantom: PhantomData,
+};
+
+/// π/8 = 0.3926…
+// FRAC_PI_8 = 0.3926990816987241548078304229099378605246
+pub const FRAC_PI_8: FixedU128<U128> = FixedU128 {
+    bits: 0x6487_ED51_10B4_611A_6263_3145_C06E_0E68,
+    phantom: PhantomData,
+};
+
+/// 1/π = 0.3183…
+// FRAC_1_PI = 0.3183098861837906715377675267450287240689
+pub const FRAC_1_PI: FixedU128<U128> = FixedU128 {
+    bits: 0x517C_C1B7_2722_0A94_FE13_ABE8_FA9A_6EE0,
+    phantom: PhantomData,
+};
+
+/// 2/π = 0.6366…
+// FRAC_2_PI = 0.6366197723675813430755350534900574481378
+pub const FRAC_2_PI: FixedU128<U128> = FixedU128 {
+    bits: 0xA2F9_836E_4E44_1529_FC27_57D1_F534_DDC0,
+    phantom: PhantomData,
+};
+
+/// 2/√π = 1.128…
+// FRAC_2_SQRT_PI = 1.128379167095512573896158903121545171688
+pub const FRAC_2_SQRT_PI: FixedU128<U127> = FixedU128 {
+    bits: 0x906E_BA82_14DB_688D_71D4_8A7F_6BFE_C344,
+    phantom: PhantomData,
+};
+
+/// √2 = 1.414…
+// SQRT_2 = 1.414213562373095048801688724209698078570
+pub const SQRT_2: FixedU128<U127> = FixedU128 {
+    bits: 0xB504_F333_F9DE_6484_597D_89B3_754A_BE9F,
+    phantom: PhantomData,
+};
+
+/// 1/√2 = 0.7071…
+// FRAC_1_SQRT_2 = 0.7071067811865475244008443621048490392848
+pub const FRAC_1_SQRT_2: FixedU128<U128> = FixedU128 {
+    bits: 0xB504_F333_F9DE_6484_597D_89B3_754A_BE9F,
+    phantom: PhantomData,
+};
+
+/// e = 2.718…
+// E = 2.718281828459045235360287471352662497757
+pub const E: FixedU128<U126> = FixedU128 {
+    bits: 0xADF8_5458_A2BB_4A9A_AFDC_5620_273D_3CF1,
+    phantom: PhantomData,
+};
+
+/// log<sub>2</sub> 10 = 3.321…
+// LOG2_10 = 3.321928094887362347870319429489390175865
+pub const LOG2_10: FixedU128<U126> = FixedU128 {
+    bits: 0xD49A_784B_CD1B_8AFE_492B_F6FF_4DAF_DB4C,
+    phantom: PhantomData,
+};
+
+/// log<sub>2</sub> e = 1.442…
+// LOG2_E = 1.442695040888963407359924681001892137427
+pub const LOG2_E: FixedU128<U127> = FixedU128 {
+    bits: 0xB8AA_3B29_5C17_F0BB_BE87_FED0_691D_3E88,
+    phantom: PhantomData,
+};
+
+/// log<sub>10</sub> 2 = 0.3010…
+// LOG10_2 = 0.3010299956639811952137388947244930267682
+pub const LOG10_2: FixedU128<U128> = FixedU128 {
+    bits: 0x4D10_4D42_7DE7_FBCC_47C4_ACD6_05BE_48BC,
+    phantom: PhantomData,
+};
+
+/// log<sub>10</sub> e = 0.4342…
+// LOG10_E = 0.4342944819032518276511289189166050822944
+pub const LOG10_E: FixedU128<U128> = FixedU128 {
+    bits: 0x6F2D_EC54_9B94_38CA_9AAD_D557_D699_EE19,
+    phantom: PhantomData,
+};
+
+/// ln 2 = 0.6931…
+// LN_2 = 0.6931471805599453094172321214581765680755
+pub const LN_2: FixedU128<U128> = FixedU128 {
+    bits: 0xB172_17F7_D1CF_79AB_C9E3_B398_03F2_F6AF,
+    phantom: PhantomData,
+};
+
+/// ln 10 = 2.302…
+// LN_10 = 2.302585092994045684017991454684364207601
+pub const LN_10: FixedU128<U126> = FixedU128 {
+    bits: 0x935D_8DDD_AAA8_AC16_EA56_D62B_82D3_0A28,
+    phantom: PhantomData,
+};
+
+#[cfg(test)]
+mod tests {
+    use crate::{consts::*, traits::FromFixed};
+    use core::f64::consts as F;
+
+    #[test]
+    #[allow(clippy::float_cmp)]
+    fn check() {
+        assert_eq!(f64::from_fixed(PI), F::PI);
+        assert_eq!(f64::from_fixed(FRAC_PI_2), F::FRAC_PI_2);
+        assert_eq!(f64::from_fixed(FRAC_PI_3), F::FRAC_PI_3);
+        assert_eq!(f64::from_fixed(FRAC_PI_4), F::FRAC_PI_4);
+        assert_eq!(f64::from_fixed(FRAC_PI_6), F::FRAC_PI_6);
+        assert_eq!(f64::from_fixed(FRAC_PI_8), F::FRAC_PI_8);
+        assert_eq!(f64::from_fixed(FRAC_1_PI), F::FRAC_1_PI);
+        assert_eq!(f64::from_fixed(FRAC_2_PI), F::FRAC_2_PI);
+        assert_eq!(f64::from_fixed(FRAC_2_SQRT_PI), F::FRAC_2_SQRT_PI);
+        assert_eq!(f64::from_fixed(SQRT_2), F::SQRT_2);
+        assert_eq!(f64::from_fixed(FRAC_1_SQRT_2), F::FRAC_1_SQRT_2);
+        assert_eq!(f64::from_fixed(E), F::E);
+        // assert_eq!(f64::from_fixed(LOG2_10), F::LOG2_10);
+        assert_eq!(f64::from_fixed(LOG2_E), F::LOG2_E);
+        // assert_eq!(f64::from_fixed(LOG10_2), F::LOG10_2);
+        assert_eq!(f64::from_fixed(LOG10_E), F::LOG10_E);
+        assert_eq!(f64::from_fixed(LN_2), F::LN_2);
+        assert_eq!(f64::from_fixed(LN_10), F::LN_10);
+    }
+}

src/lib.rs

@@ -194,6 +194,7 @@ mod macros;
 
 mod arith;
 mod cmp;
+pub mod consts;
 mod convert;
 mod display;
 pub mod frac;

src/traits.rs

@@ -15,7 +15,7 @@
 
 /*!
 This module contains traits.
- */
+*/
 
 use crate::{
     frac::{IsLessOrEqual, True, Unsigned, U128, U16, U32, U64, U8},