3 unstable releases
0.2.0 | Jun 20, 2022 |
---|---|
0.1.1 | Jun 19, 2022 |
0.1.0 | May 7, 2022 |
#769 in Math
40KB
452 lines
quaternion-wrapper
This is a wrapper for the quaternion-core crate.
Provides quaternion operations and interconversion with several attitude representations.
Operator overloading allows implementation similar to mathematical expressions.
Usage
Add this to your Cargo.toml
:
[dependencies]
quaternion-wrapper = "0.2"
Operator Overloading
Operator overloading allows operations between QuaternionWrapper
, Vector3Wrapper
, and ScalarWrapper
.
The supported operations are listed in the table below:
Left↓ / Right→ | QuaternionWrapper | Vector3Wrapper | ScalarWrapper |
---|---|---|---|
QuaternionWrapper | + , - , * , += , -= , *= |
+ , - , * |
+ , - , * , / |
Vector3Wrapper | + , - , * |
+ , - , * , += , -= |
+ , - , * , / |
ScalarWrapper | + , - , * |
+ , - , * |
+ , - , * , / , += , -= , *= , /= |
To prevent implementation errors by users, the operation with T
(f32
or f64
) is
intentionally not implemented.
That is, ScalarWrapper<f64> * QuaternionWrapper<f64>
can be calculated,
but f64 * QuaternionWrapper<f64>
cannot.
Features
Cargo.toml
:
[dependencies.quaternion-wrapper]
version = "0.2"
# Uncomment if you wish to use FMA.
#features = ["fma"]
# Uncomment if you wish to use in "no_std" environment.
#default-features = false
#features = ["libm"]
fma
This library uses the
mul_add
method mainly to improve the performance, but by default it is replace with a unfused multiply-add
(s*a + b
) . If you wish to use mul_add method, enable the fma
feature.
If your CPU does not support FMA instructions, or if you use libm
(running in no_std
environment), enabling the fma
feature may cause slowdown of computation speed. Also,
due to rounding error, results of s.mul_add(a, b)
and s*a + b
will not match perfectly.
libm & default-features = false
These options allow for use in the no_std
environment.
In this case, mathematical functions (e.g. sin, cos, sqrt ...) are provided by
libm.
Example
src/main.rs
:
use quaternion_wrapper::{QuaternionWrapper, Vector3Wrapper};
const PI: f64 = std::f64::consts::PI;
const EPSILON: f64 = 1e-12;
fn main() {
// Generates a quaternion representing the
// rotation of π/2[rad] around the y-axis.
let q = QuaternionWrapper::from_axis_angle([0.0, 1.0, 0.0], PI/2.0);
// Point
let v = Vector3Wrapper([2.0, 2.0, 0.0]);
let result = (q * v * q.conj()).get_vector_part();
//let result = q.point_rotation(v); // <--- It could be written like this
// Check if the calculation is correct.
let true_val = Vector3Wrapper([0.0, 2.0, -2.0]);
let diff: [f64; 3] = (true_val - result).unwrap();
for val in diff {
assert!(val.abs() < EPSILON);
}
}
License
Licensed under either of Apache License, Version 2.0 or MIT License at your option.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
Dependencies
~175–290KB