rust_3d/
utils.rs

1/*
2Copyright 2017 Martin Buck
3
4Permission is hereby granted, free of charge, to any person obtaining a copy
5of this software and associated documentation files (the "Software"),
6to deal in the Software without restriction, including without limitation the
7rights to use, copy, modify, merge, publish, distribute, sublicense,
8and/or sell copies of the Software, and to permit persons to whom the Software
9is furnished to do so, subject to the following conditions:
10
11The above copyright notice and this permission notice shall
12be included all copies or substantial portions of the Software.
13
14THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
17IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
18DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
19TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
20OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
21*/
22
23//! internal utility functions
24
25use std::{
26    collections::HashMap,
27    hash::{Hash, Hasher},
28};
29
30use crate::*;
31
32//------------------------------------------------------------------------------
33
34/// Splits an ASCII line into its words, skipping empty elements
35pub fn to_words_skip_empty(line: &[u8]) -> impl Iterator<Item = &[u8]> {
36    line.split(|x| *x == b' ' || *x == b'\t').skip_empty()
37}
38
39/// Returns all until delimiter
40pub fn until<'a>(line: &'a str, delimiter: &str) -> &'a str {
41    line.split(delimiter).next().unwrap_or("")
42}
43
44/// Returns all until delimiter
45pub fn until_bytes<'a>(line: &'a [u8], delimiter: u8) -> &'a [u8] {
46    line.split(|x| *x == delimiter).next().unwrap_or(&[])
47}
48
49/// Max of two f64 values
50pub fn max_f64(a: f64, b: f64) -> f64 {
51    if a > b {
52        return a;
53    }
54    b
55}
56
57/// Checks whether haystack contains needle
58pub fn contains<T>(haystack: &[T], needle: &[T]) -> bool
59where
60    T: PartialEq,
61{
62    haystack.windows(needle.len()).any(|x| x == needle)
63}
64
65/// Max of three f64 values
66pub fn max_f64_3(a: f64, b: f64, c: f64) -> f64 {
67    max_f64(max_f64(a, b), c)
68}
69
70/// Generates the hash of an f64
71#[inline(always)]
72pub fn hash_f64<H>(x: f64, state: &mut H)
73where
74    H: Hasher,
75{
76    x.to_bits().hash(state);
77}
78
79/// Returns a container with duplicates removed and indices representing the original order
80pub fn pack_dupes_indexed<'a, I, T>(idata: I) -> (Vec<T>, Vec<usize>)
81where
82    I: Iterator<Item = &'a T>,
83    T: 'a + Eq + Hash + Clone,
84{
85    let mut map = HashMap::new();
86    let mut packed_data = Vec::new();
87    let mut ids = Vec::new();
88    for x in idata {
89        let id = map.entry(x).or_insert_with(|| {
90            let value = packed_data.len();
91            packed_data.push(x.clone());
92            value
93        });
94        ids.push(*id);
95    }
96
97    (packed_data, ids)
98}
99
100/// Calculates the normals of a mesh
101pub fn normals_of_mesh<P, M>(mesh: &M) -> Vec<Norm3D>
102where
103    M: IsMesh<P, Face3>,
104    P: IsBuildable3D + Default + Clone,
105{
106    let n = mesh.num_vertices();
107    let nf = mesh.num_faces();
108    let mut ns = vec![P::default(); n];
109
110    for i in 0..nf {
111        let face = mesh.face_vertex_ids(FId { val: i }).unwrap(); // safe
112        let [v1, v2, v3] = mesh.face_vertices(FId { val: i }).unwrap(); // safe
113        let v12 = conn(&v1, &v2);
114        let v13 = conn(&v1, &v3);
115        let n = Norm3D::new(cross(&v12, &v13)).unwrap_or(Norm3D::norm_z());
116        for j in 0..3 {
117            let new = add(&ns[face.vid(j).unwrap().val], &n); // safe since iterating 0..3
118            ns[face.vid(j).unwrap().val] = new; // safe since iterating 0..3
119        }
120    }
121
122    ns.into_iter()
123        .map(|x| Norm3D::new(x).unwrap_or(Norm3D::norm_z()))
124        .collect()
125}
126
127/// Estimates the used delimiter within a string
128pub fn estimate_delimiter(minimum_count: usize, line: &[u8]) -> Option<u8> {
129    for candidate in [b' ', b';', b',', b'\t'].iter() {
130        if line.iter().filter(|c| **c == *candidate).count() >= minimum_count {
131            return Some(*candidate);
132        }
133    }
134    None
135}
136
137/// Adds two Is3D values
138pub fn add<P, Q>(p: &P, q: &Q) -> P
139where
140    P: IsBuildable3D,
141    Q: Is3D,
142{
143    P::new(p.x() + q.x(), p.y() + q.y(), p.z() + q.z())
144}
rust_3d/utils.rs

rust_3d/
utils.rs
