pic_scale/math/
sphinx.rs

1/*
2 * Copyright (c) Radzivon Bartoshyk. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without modification,
5 * are permitted provided that the following conditions are met:
6 *
7 * 1.  Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * 2.  Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * 3.  Neither the name of the copyright holder nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
25 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30use crate::math::consts::ConstPI;
31use crate::math::mla;
32use crate::math::sinc::Trigonometry;
33use num_traits::{AsPrimitive, Float, MulAdd, Signed};
34
35pub(crate) fn sphinx<
36    V: Copy + ConstPI + Signed + Float + 'static + Trigonometry + MulAdd<V, Output = V>,
37>(
38    x: V,
39) -> V
40where
41    f32: AsPrimitive<V>,
42{
43    if x.abs() < 1e-8.as_() {
44        return 1f32.as_();
45    }
46    let (x_sin, x_cos) = x.f_sincospi();
47    3.0f32.as_() * mla(-x, x_cos, x_sin) / (x * x * x)
48}
pic_scale/math/sphinx.rs

pic_scale/math/
sphinx.rs
