<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `geom&#x2F;src&#x2F;angle.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>angle.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../ayu.css" disabled><link rel="stylesheet" type="text/css" href="../../dark.css" disabled><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script src="../../crates.js"></script><script defer src="../../main.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script>
    <noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu" role="button">&#9776;</div><a class="sidebar-logo" href="../../geom/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.png" alt="logo"></div>
        </a></nav><main><div class="width-limiter"><div class="sub-container"><a class="sub-logo-container" href="../../geom/index.html"><img class="rust-logo" src="../../rust-logo.png" alt="logo"></a><nav class="sub"><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu" title="themes"><img width="18" height="18" alt="Pick another theme!" src="../../brush.svg"></button><div id="theme-choices" role="menu"></div></div><form class="search-form"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><button type="button" id="help-button" title="help">?</button><a id="settings-menu" href="../../settings.html" title="settings"><img width="18" height="18" alt="Change settings" src="../../wheel.svg"></a></div></form></nav></div><section id="main-content" class="content"><div class="example-wrap"><pre class="line-numbers"><span id="1">  1</span>
<span id="2">  2</span>
<span id="3">  3</span>
<span id="4">  4</span>
<span id="5">  5</span>
<span id="6">  6</span>
<span id="7">  7</span>
<span id="8">  8</span>
<span id="9">  9</span>
<span id="10"> 10</span>
<span id="11"> 11</span>
<span id="12"> 12</span>
<span id="13"> 13</span>
<span id="14"> 14</span>
<span id="15"> 15</span>
<span id="16"> 16</span>
<span id="17"> 17</span>
<span id="18"> 18</span>
<span id="19"> 19</span>
<span id="20"> 20</span>
<span id="21"> 21</span>
<span id="22"> 22</span>
<span id="23"> 23</span>
<span id="24"> 24</span>
<span id="25"> 25</span>
<span id="26"> 26</span>
<span id="27"> 27</span>
<span id="28"> 28</span>
<span id="29"> 29</span>
<span id="30"> 30</span>
<span id="31"> 31</span>
<span id="32"> 32</span>
<span id="33"> 33</span>
<span id="34"> 34</span>
<span id="35"> 35</span>
<span id="36"> 36</span>
<span id="37"> 37</span>
<span id="38"> 38</span>
<span id="39"> 39</span>
<span id="40"> 40</span>
<span id="41"> 41</span>
<span id="42"> 42</span>
<span id="43"> 43</span>
<span id="44"> 44</span>
<span id="45"> 45</span>
<span id="46"> 46</span>
<span id="47"> 47</span>
<span id="48"> 48</span>
<span id="49"> 49</span>
<span id="50"> 50</span>
<span id="51"> 51</span>
<span id="52"> 52</span>
<span id="53"> 53</span>
<span id="54"> 54</span>
<span id="55"> 55</span>
<span id="56"> 56</span>
<span id="57"> 57</span>
<span id="58"> 58</span>
<span id="59"> 59</span>
<span id="60"> 60</span>
<span id="61"> 61</span>
<span id="62"> 62</span>
<span id="63"> 63</span>
<span id="64"> 64</span>
<span id="65"> 65</span>
<span id="66"> 66</span>
<span id="67"> 67</span>
<span id="68"> 68</span>
<span id="69"> 69</span>
<span id="70"> 70</span>
<span id="71"> 71</span>
<span id="72"> 72</span>
<span id="73"> 73</span>
<span id="74"> 74</span>
<span id="75"> 75</span>
<span id="76"> 76</span>
<span id="77"> 77</span>
<span id="78"> 78</span>
<span id="79"> 79</span>
<span id="80"> 80</span>
<span id="81"> 81</span>
<span id="82"> 82</span>
<span id="83"> 83</span>
<span id="84"> 84</span>
<span id="85"> 85</span>
<span id="86"> 86</span>
<span id="87"> 87</span>
<span id="88"> 88</span>
<span id="89"> 89</span>
<span id="90"> 90</span>
<span id="91"> 91</span>
<span id="92"> 92</span>
<span id="93"> 93</span>
<span id="94"> 94</span>
<span id="95"> 95</span>
<span id="96"> 96</span>
<span id="97"> 97</span>
<span id="98"> 98</span>
<span id="99"> 99</span>
<span id="100">100</span>
<span id="101">101</span>
<span id="102">102</span>
<span id="103">103</span>
<span id="104">104</span>
<span id="105">105</span>
<span id="106">106</span>
<span id="107">107</span>
<span id="108">108</span>
<span id="109">109</span>
<span id="110">110</span>
<span id="111">111</span>
<span id="112">112</span>
<span id="113">113</span>
<span id="114">114</span>
<span id="115">115</span>
<span id="116">116</span>
<span id="117">117</span>
<span id="118">118</span>
<span id="119">119</span>
<span id="120">120</span>
<span id="121">121</span>
<span id="122">122</span>
<span id="123">123</span>
<span id="124">124</span>
<span id="125">125</span>
<span id="126">126</span>
<span id="127">127</span>
<span id="128">128</span>
<span id="129">129</span>
<span id="130">130</span>
<span id="131">131</span>
<span id="132">132</span>
<span id="133">133</span>
<span id="134">134</span>
<span id="135">135</span>
<span id="136">136</span>
<span id="137">137</span>
</pre><pre class="rust"><code><span class="kw">use</span> <span class="ident">std::fmt</span>;

<span class="kw">use</span> <span class="ident">serde</span>::{<span class="ident">Deserialize</span>, <span class="ident">Serialize</span>};

<span class="doccomment">/// An angle, stored in radians.</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Copy</span>, <span class="ident">Debug</span>, <span class="ident">Serialize</span>, <span class="ident">Deserialize</span>, <span class="ident">PartialEq</span>, <span class="ident">PartialOrd</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Angle</span>(<span class="ident">f64</span>);

<span class="kw">impl</span> <span class="ident">Angle</span> {
    <span class="kw">pub</span> <span class="kw">const</span> <span class="ident">ZERO</span>: <span class="ident">Angle</span> <span class="op">=</span> <span class="ident">Angle</span>(<span class="number">0.0</span>);

    <span class="doccomment">/// Create an angle in radians.</span>
    <span class="comment">// TODO Normalize here, and be careful about % vs euclid_rem</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new_rads</span>(<span class="ident">rads</span>: <span class="ident">f64</span>) -&gt; <span class="ident">Angle</span> {
        <span class="comment">// Retain more precision for angles...</span>
        <span class="ident">Angle</span>((<span class="ident">rads</span> <span class="op">*</span> <span class="number">10_000_000.0</span>).<span class="ident">round</span>() <span class="op">/</span> <span class="number">10_000_000.0</span>)
    }

    <span class="doccomment">/// Create an angle in degrees.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">degrees</span>(<span class="ident">degs</span>: <span class="ident">f64</span>) -&gt; <span class="ident">Angle</span> {
        <span class="ident">Angle::new_rads</span>(<span class="ident">degs</span>.<span class="ident">to_radians</span>())
    }

    <span class="doccomment">/// Invert the direction of this angle.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">opposite</span>(<span class="self">self</span>) -&gt; <span class="ident">Angle</span> {
        <span class="ident">Angle::new_rads</span>(<span class="self">self</span>.<span class="number">0</span> <span class="op">+</span> <span class="ident">std::f64::consts::PI</span>)
    }

    <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn</span> <span class="ident">invert_y</span>(<span class="self">self</span>) -&gt; <span class="ident">Angle</span> {
        <span class="ident">Angle::new_rads</span>(<span class="number">2.0</span> <span class="op">*</span> <span class="ident">std::f64::consts::PI</span> <span class="op">-</span> <span class="self">self</span>.<span class="number">0</span>)
    }

    <span class="doccomment">/// Rotates this angle by some degrees.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">rotate_degs</span>(<span class="self">self</span>, <span class="ident">degrees</span>: <span class="ident">f64</span>) -&gt; <span class="ident">Angle</span> {
        <span class="ident">Angle::new_rads</span>(<span class="self">self</span>.<span class="number">0</span> <span class="op">+</span> <span class="ident">degrees</span>.<span class="ident">to_radians</span>())
    }

    <span class="doccomment">/// Returns [0, 2pi)</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">normalized_radians</span>(<span class="self">self</span>) -&gt; <span class="ident">f64</span> {
        <span class="kw">if</span> <span class="self">self</span>.<span class="number">0</span> <span class="op">&lt;</span> <span class="number">0.0</span> {
            <span class="comment">// TODO Be more careful about how we store the angle, to make sure this works</span>
            <span class="self">self</span>.<span class="number">0</span> <span class="op">+</span> (<span class="number">2.0</span> <span class="op">*</span> <span class="ident">std::f64::consts::PI</span>)
        } <span class="kw">else</span> {
            <span class="self">self</span>.<span class="number">0</span>
        }
    }

    <span class="doccomment">/// Returns [0, 360)</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">normalized_degrees</span>(<span class="self">self</span>) -&gt; <span class="ident">f64</span> {
        <span class="self">self</span>.<span class="ident">normalized_radians</span>().<span class="ident">to_degrees</span>()
    }

    <span class="doccomment">/// Returns [-180, 180]</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">simple_shortest_rotation_towards</span>(<span class="self">self</span>, <span class="ident">other</span>: <span class="ident">Angle</span>) -&gt; <span class="ident">f64</span> {
        <span class="comment">// https://math.stackexchange.com/questions/110080/shortest-way-to-achieve-target-angle</span>
        ((<span class="self">self</span>.<span class="ident">normalized_degrees</span>() <span class="op">-</span> <span class="ident">other</span>.<span class="ident">normalized_degrees</span>() <span class="op">+</span> <span class="number">540.0</span>) <span class="op">%</span> <span class="number">360.0</span>) <span class="op">-</span> <span class="number">180.0</span>
    }

    <span class="doccomment">/// Logically this returns [-180, 180], but keep in mind when we print this angle, it&#39;ll</span>
    <span class="doccomment">/// normalize to be [0, 360].</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">shortest_rotation_towards</span>(<span class="self">self</span>, <span class="ident">other</span>: <span class="ident">Angle</span>) -&gt; <span class="ident">Angle</span> {
        <span class="ident">Angle::degrees</span>(<span class="self">self</span>.<span class="ident">simple_shortest_rotation_towards</span>(<span class="ident">other</span>))
    }

    <span class="doccomment">/// True if this angle is within some degrees of another, accounting for rotation</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">approx_eq</span>(<span class="self">self</span>, <span class="ident">other</span>: <span class="ident">Angle</span>, <span class="ident">within_degrees</span>: <span class="ident">f64</span>) -&gt; <span class="ident">bool</span> {
        <span class="self">self</span>.<span class="ident">simple_shortest_rotation_towards</span>(<span class="ident">other</span>).<span class="ident">abs</span>() <span class="op">&lt;</span> <span class="ident">within_degrees</span>
    }

    <span class="doccomment">/// True if this angle is within some degrees of another, accounting for rotation and allowing</span>
    <span class="doccomment">/// two angles that point in opposite directions</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">approx_parallel</span>(<span class="self">self</span>, <span class="ident">other</span>: <span class="ident">Angle</span>, <span class="ident">within_degrees</span>: <span class="ident">f64</span>) -&gt; <span class="ident">bool</span> {
        <span class="self">self</span>.<span class="ident">approx_eq</span>(<span class="ident">other</span>, <span class="ident">within_degrees</span>) <span class="op">|</span><span class="op">|</span> <span class="self">self</span>.<span class="ident">opposite</span>().<span class="ident">approx_eq</span>(<span class="ident">other</span>, <span class="ident">within_degrees</span>)
    }

    <span class="doccomment">/// I don&#39;t know how to describe what this does. Use for rotating labels in map-space and making</span>
    <span class="doccomment">/// sure the text is never upside-down.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">reorient</span>(<span class="self">self</span>) -&gt; <span class="ident">Angle</span> {
        <span class="kw">let</span> <span class="ident">theta</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">normalized_degrees</span>().<span class="ident">rem_euclid</span>(<span class="number">360.0</span>);
        <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">result</span> <span class="op">=</span> <span class="self">self</span>;
        <span class="kw">if</span> <span class="ident">theta</span> <span class="op">&gt;</span> <span class="number">90.0</span> {
            <span class="ident">result</span> <span class="op">=</span> <span class="ident">result</span>.<span class="ident">opposite</span>();
        }
        <span class="kw">if</span> <span class="ident">theta</span> <span class="op">&gt;</span> <span class="number">270.0</span> {
            <span class="ident">result</span> <span class="op">=</span> <span class="ident">result</span>.<span class="ident">opposite</span>();
        }
        <span class="ident">result</span>
    }

    <span class="doccomment">/// Calculates the average of some angles.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">average</span>(<span class="ident">input</span>: <span class="ident">Vec</span><span class="op">&lt;</span><span class="ident">Angle</span><span class="op">&gt;</span>) -&gt; <span class="ident">Angle</span> {
        <span class="comment">// Thanks https://rosettacode.org/wiki/Averages/Mean_angle</span>
        <span class="kw">let</span> <span class="ident">num</span> <span class="op">=</span> <span class="ident">input</span>.<span class="ident">len</span>() <span class="kw">as</span> <span class="ident">f64</span>;
        <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">cos_sum</span> <span class="op">=</span> <span class="number">0.0</span>;
        <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">sin_sum</span> <span class="op">=</span> <span class="number">0.0</span>;
        <span class="kw">for</span> <span class="ident">x</span> <span class="kw">in</span> <span class="ident">input</span> {
            <span class="ident">cos_sum</span> <span class="op">+</span><span class="op">=</span> <span class="ident">x</span>.<span class="number">0</span>.<span class="ident">cos</span>();
            <span class="ident">sin_sum</span> <span class="op">+</span><span class="op">=</span> <span class="ident">x</span>.<span class="number">0</span>.<span class="ident">sin</span>();
        }
        <span class="ident">Angle::new_rads</span>((<span class="ident">sin_sum</span> <span class="op">/</span> <span class="ident">num</span>).<span class="ident">atan2</span>(<span class="ident">cos_sum</span> <span class="op">/</span> <span class="ident">num</span>))
    }
}

<span class="kw">impl</span> <span class="ident">fmt::Display</span> <span class="kw">for</span> <span class="ident">Angle</span> {
    <span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&amp;mut</span> <span class="ident">fmt::Formatter</span>) -&gt; <span class="ident">fmt::Result</span> {
        <span class="macro">write!</span>(<span class="ident">f</span>, <span class="string">&quot;Angle({} degrees)&quot;</span>, <span class="self">self</span>.<span class="ident">normalized_degrees</span>())
    }
}

<span class="kw">impl</span> <span class="ident">std::ops::Add</span> <span class="kw">for</span> <span class="ident">Angle</span> {
    <span class="kw">type</span> <span class="ident">Output</span> <span class="op">=</span> <span class="ident">Angle</span>;

    <span class="kw">fn</span> <span class="ident">add</span>(<span class="self">self</span>, <span class="ident">other</span>: <span class="ident">Angle</span>) -&gt; <span class="ident">Angle</span> {
        <span class="ident">Angle::new_rads</span>(<span class="self">self</span>.<span class="number">0</span> <span class="op">+</span> <span class="ident">other</span>.<span class="number">0</span>)
    }
}

<span class="kw">impl</span> <span class="ident">std::ops::Neg</span> <span class="kw">for</span> <span class="ident">Angle</span> {
    <span class="kw">type</span> <span class="ident">Output</span> <span class="op">=</span> <span class="ident">Angle</span>;

    <span class="kw">fn</span> <span class="ident">neg</span>(<span class="self">self</span>) -&gt; <span class="ident">Angle</span> {
        <span class="ident">Angle::new_rads</span>(<span class="op">-</span><span class="self">self</span>.<span class="number">0</span>)
    }
}

<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
<span class="kw">mod</span> <span class="ident">tests</span> {
    <span class="kw">use</span> <span class="kw">super</span>::<span class="kw-2">*</span>;

    <span class="attribute">#[<span class="ident">test</span>]</span>
    <span class="kw">fn</span> <span class="ident">test_average</span>() {
        <span class="macro">assert_eq!</span>(
            <span class="ident">Angle::degrees</span>(<span class="number">30.0</span>),
            <span class="ident">Angle::average</span>(<span class="macro">vec!</span>[<span class="ident">Angle::degrees</span>(<span class="number">30.0</span>)])
        );
    }
}
</code></pre></div>
</section><section id="search" class="content hidden"></section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="geom" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.59.0 (9d1b2106e 2022-02-23)" ></div>
</body></html>