<!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;line.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>line.rs - source</title><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="../../light.css"  id="themeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css" disabled ><link rel="stylesheet" type="text/css" href="../../ayu.css" disabled ><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"><style type="text/css">#crate-search{background-image:url("../../down-arrow.svg");}</style></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 href='../../geom/index.html'><div class='logo-container rust-logo'><img src='../../rust-logo.png' alt='logo'></div></a></nav><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><nav class="sub"><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><section id="main" 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>
<span id="138">138</span>
<span id="139">139</span>
<span id="140">140</span>
<span id="141">141</span>
<span id="142">142</span>
<span id="143">143</span>
<span id="144">144</span>
<span id="145">145</span>
<span id="146">146</span>
<span id="147">147</span>
<span id="148">148</span>
<span id="149">149</span>
<span id="150">150</span>
<span id="151">151</span>
<span id="152">152</span>
<span id="153">153</span>
<span id="154">154</span>
<span id="155">155</span>
<span id="156">156</span>
<span id="157">157</span>
<span id="158">158</span>
<span id="159">159</span>
<span id="160">160</span>
<span id="161">161</span>
<span id="162">162</span>
<span id="163">163</span>
<span id="164">164</span>
<span id="165">165</span>
<span id="166">166</span>
<span id="167">167</span>
<span id="168">168</span>
<span id="169">169</span>
<span id="170">170</span>
<span id="171">171</span>
<span id="172">172</span>
<span id="173">173</span>
<span id="174">174</span>
<span id="175">175</span>
<span id="176">176</span>
<span id="177">177</span>
<span id="178">178</span>
<span id="179">179</span>
<span id="180">180</span>
<span id="181">181</span>
<span id="182">182</span>
<span id="183">183</span>
<span id="184">184</span>
<span id="185">185</span>
<span id="186">186</span>
<span id="187">187</span>
<span id="188">188</span>
<span id="189">189</span>
<span id="190">190</span>
<span id="191">191</span>
<span id="192">192</span>
<span id="193">193</span>
<span id="194">194</span>
<span id="195">195</span>
<span id="196">196</span>
<span id="197">197</span>
<span id="198">198</span>
<span id="199">199</span>
<span id="200">200</span>
<span id="201">201</span>
<span id="202">202</span>
<span id="203">203</span>
<span id="204">204</span>
<span id="205">205</span>
<span id="206">206</span>
<span id="207">207</span>
<span id="208">208</span>
<span id="209">209</span>
<span id="210">210</span>
<span id="211">211</span>
<span id="212">212</span>
<span id="213">213</span>
<span id="214">214</span>
<span id="215">215</span>
<span id="216">216</span>
<span id="217">217</span>
<span id="218">218</span>
<span id="219">219</span>
<span id="220">220</span>
<span id="221">221</span>
<span id="222">222</span>
<span id="223">223</span>
<span id="224">224</span>
<span id="225">225</span>
<span id="226">226</span>
<span id="227">227</span>
<span id="228">228</span>
<span id="229">229</span>
<span id="230">230</span>
<span id="231">231</span>
<span id="232">232</span>
<span id="233">233</span>
<span id="234">234</span>
<span id="235">235</span>
<span id="236">236</span>
<span id="237">237</span>
<span id="238">238</span>
<span id="239">239</span>
<span id="240">240</span>
<span id="241">241</span>
<span id="242">242</span>
<span id="243">243</span>
<span id="244">244</span>
<span id="245">245</span>
<span id="246">246</span>
<span id="247">247</span>
<span id="248">248</span>
<span id="249">249</span>
<span id="250">250</span>
<span id="251">251</span>
<span id="252">252</span>
<span id="253">253</span>
<span id="254">254</span>
<span id="255">255</span>
<span id="256">256</span>
<span id="257">257</span>
<span id="258">258</span>
<span id="259">259</span>
<span id="260">260</span>
<span id="261">261</span>
<span id="262">262</span>
<span id="263">263</span>
<span id="264">264</span>
<span id="265">265</span>
<span id="266">266</span>
<span id="267">267</span>
<span id="268">268</span>
<span id="269">269</span>
<span id="270">270</span>
<span id="271">271</span>
<span id="272">272</span>
<span id="273">273</span>
<span id="274">274</span>
<span id="275">275</span>
<span id="276">276</span>
<span id="277">277</span>
<span id="278">278</span>
<span id="279">279</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">anyhow::Result</span>;
<span class="kw">use</span> <span class="ident">serde</span>::{<span class="ident">Deserialize</span>, <span class="ident">Serialize</span>};

<span class="kw">use</span> <span class="kw">crate</span>::{<span class="ident">Angle</span>, <span class="ident">Distance</span>, <span class="ident">PolyLine</span>, <span class="ident">Polygon</span>, <span class="ident">Pt2D</span>, <span class="ident">EPSILON_DIST</span>};

<span class="doccomment">/// A line segment.</span>
<span class="comment">// TODO Rename?</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Serialize</span>, <span class="ident">Deserialize</span>, <span class="ident">Debug</span>, <span class="ident">PartialEq</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Line</span>(<span class="ident">Pt2D</span>, <span class="ident">Pt2D</span>);

<span class="kw">impl</span> <span class="ident">Line</span> {
    <span class="doccomment">/// Creates a line segment between two points, which must not be the same</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">pt1</span>: <span class="ident">Pt2D</span>, <span class="ident">pt2</span>: <span class="ident">Pt2D</span>) -&gt; <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">Line</span><span class="op">&gt;</span> {
        <span class="kw">if</span> <span class="ident">pt1</span>.<span class="ident">dist_to</span>(<span class="ident">pt2</span>) <span class="op">&lt;</span><span class="op">=</span> <span class="ident">EPSILON_DIST</span> {
            <span class="macro">bail!</span>(<span class="string">&quot;Line from {:?} to {:?} too small&quot;</span>, <span class="ident">pt1</span>, <span class="ident">pt2</span>);
        }
        <span class="prelude-val">Ok</span>(<span class="ident">Line</span>(<span class="ident">pt1</span>, <span class="ident">pt2</span>))
    }

    <span class="doccomment">/// Equivalent to `Line::new(pt1, pt2).unwrap()`. Use this to effectively document an assertion</span>
    <span class="doccomment">/// at the call-site.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">must_new</span>(<span class="ident">pt1</span>: <span class="ident">Pt2D</span>, <span class="ident">pt2</span>: <span class="ident">Pt2D</span>) -&gt; <span class="ident">Line</span> {
        <span class="ident">Line::new</span>(<span class="ident">pt1</span>, <span class="ident">pt2</span>).<span class="ident">unwrap</span>()
    }

    <span class="doccomment">/// Returns an infinite line passing through this line&#39;s two points.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">infinite</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">InfiniteLine</span> {
        <span class="ident">InfiniteLine</span>(<span class="self">self</span>.<span class="number">0</span>, <span class="self">self</span>.<span class="number">1</span>)
    }

    <span class="doccomment">/// Returns the first point in this line segment.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">pt1</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">Pt2D</span> {
        <span class="self">self</span>.<span class="number">0</span>
    }

    <span class="doccomment">/// Returns the second point in this line segment.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">pt2</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">Pt2D</span> {
        <span class="self">self</span>.<span class="number">1</span>
    }

    <span class="doccomment">/// Returns the two points in this line segment.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">points</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">Vec</span><span class="op">&lt;</span><span class="ident">Pt2D</span><span class="op">&gt;</span> {
        <span class="macro">vec!</span>[<span class="self">self</span>.<span class="number">0</span>, <span class="self">self</span>.<span class="number">1</span>]
    }

    <span class="doccomment">/// Returns a polyline containing these two points.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">to_polyline</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">PolyLine</span> {
        <span class="ident">PolyLine::must_new</span>(<span class="self">self</span>.<span class="ident">points</span>())
    }

    <span class="doccomment">/// Returns a thick line segment.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">make_polygons</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">thickness</span>: <span class="ident">Distance</span>) -&gt; <span class="ident">Polygon</span> {
        <span class="self">self</span>.<span class="ident">to_polyline</span>().<span class="ident">make_polygons</span>(<span class="ident">thickness</span>)
    }

    <span class="doccomment">/// Length of the line segment</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">length</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">Distance</span> {
        <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">dist_to</span>(<span class="self">self</span>.<span class="ident">pt2</span>())
    }

    <span class="doccomment">/// If two line segments intersect -- including endpoints -- return the point where they hit.</span>
    <span class="doccomment">/// Undefined if the two lines have more than one intersection point!</span>
    <span class="comment">// TODO Also return the distance along self</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">intersection</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">other</span>: <span class="kw-2">&amp;</span><span class="ident">Line</span>) -&gt; <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">Pt2D</span><span class="op">&gt;</span> {
        <span class="comment">// From http://bryceboe.com/2006/10/23/line-segment-intersection-algorithm/</span>
        <span class="kw">if</span> <span class="ident">is_counter_clockwise</span>(<span class="self">self</span>.<span class="ident">pt1</span>(), <span class="ident">other</span>.<span class="ident">pt1</span>(), <span class="ident">other</span>.<span class="ident">pt2</span>())
            <span class="op">==</span> <span class="ident">is_counter_clockwise</span>(<span class="self">self</span>.<span class="ident">pt2</span>(), <span class="ident">other</span>.<span class="ident">pt1</span>(), <span class="ident">other</span>.<span class="ident">pt2</span>())
            <span class="op">|</span><span class="op">|</span> <span class="ident">is_counter_clockwise</span>(<span class="self">self</span>.<span class="ident">pt1</span>(), <span class="self">self</span>.<span class="ident">pt2</span>(), <span class="ident">other</span>.<span class="ident">pt1</span>())
                <span class="op">==</span> <span class="ident">is_counter_clockwise</span>(<span class="self">self</span>.<span class="ident">pt1</span>(), <span class="self">self</span>.<span class="ident">pt2</span>(), <span class="ident">other</span>.<span class="ident">pt2</span>())
        {
            <span class="kw">return</span> <span class="prelude-val">None</span>;
        }

        <span class="kw">let</span> <span class="ident">hit</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">infinite</span>().<span class="ident">intersection</span>(<span class="kw-2">&amp;</span><span class="ident">other</span>.<span class="ident">infinite</span>())<span class="question-mark">?</span>;
        <span class="kw">if</span> <span class="self">self</span>.<span class="ident">contains_pt</span>(<span class="ident">hit</span>) {
            <span class="comment">// TODO and other contains pt, then we dont need ccw check thing</span>
            <span class="prelude-val">Some</span>(<span class="ident">hit</span>)
        } <span class="kw">else</span> {
            <span class="comment">// TODO Should be impossible, but I was hitting it somewhere</span>
            <span class="macro">println!</span>(
                <span class="string">&quot;{} and {} intersect, but first line doesn&#39;t contain_pt({})&quot;</span>,
                <span class="self">self</span>, <span class="ident">other</span>, <span class="ident">hit</span>
            );
            <span class="prelude-val">None</span>
        }
    }

    <span class="doccomment">/// Determine if two line segments intersect, but more so than just two endpoints touching.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">crosses</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">other</span>: <span class="kw-2">&amp;</span><span class="ident">Line</span>) -&gt; <span class="ident">bool</span> {
        <span class="attribute">#[<span class="ident">allow</span>(<span class="ident">clippy::suspicious_operation_groupings</span>)]</span> <span class="comment">// false positive</span>
        <span class="kw">if</span> <span class="self">self</span>.<span class="ident">pt1</span>() <span class="op">==</span> <span class="ident">other</span>.<span class="ident">pt1</span>()
            <span class="op">|</span><span class="op">|</span> <span class="self">self</span>.<span class="ident">pt1</span>() <span class="op">==</span> <span class="ident">other</span>.<span class="ident">pt2</span>()
            <span class="op">|</span><span class="op">|</span> <span class="self">self</span>.<span class="ident">pt2</span>() <span class="op">==</span> <span class="ident">other</span>.<span class="ident">pt1</span>()
            <span class="op">|</span><span class="op">|</span> <span class="self">self</span>.<span class="ident">pt2</span>() <span class="op">==</span> <span class="ident">other</span>.<span class="ident">pt2</span>()
        {
            <span class="kw">return</span> <span class="bool-val">false</span>;
        }
        <span class="self">self</span>.<span class="ident">intersection</span>(<span class="ident">other</span>).<span class="ident">is_some</span>()
    }

    <span class="doccomment">/// If the line segment intersects with an infinite line -- including endpoints -- return the</span>
    <span class="doccomment">/// point where they hit. Undefined if the segment and infinite line intersect at more than one</span>
    <span class="doccomment">/// point!</span>
    <span class="comment">// TODO Also return the distance along self</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">intersection_infinite</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">other</span>: <span class="kw-2">&amp;</span><span class="ident">InfiniteLine</span>) -&gt; <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">Pt2D</span><span class="op">&gt;</span> {
        <span class="kw">let</span> <span class="ident">hit</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">infinite</span>().<span class="ident">intersection</span>(<span class="ident">other</span>)<span class="question-mark">?</span>;
        <span class="kw">if</span> <span class="self">self</span>.<span class="ident">contains_pt</span>(<span class="ident">hit</span>) {
            <span class="prelude-val">Some</span>(<span class="ident">hit</span>)
        } <span class="kw">else</span> {
            <span class="prelude-val">None</span>
        }
    }

    <span class="doccomment">/// Perpendicularly shifts the line over to the right. Width must be non-negative.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">shift_right</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">width</span>: <span class="ident">Distance</span>) -&gt; <span class="ident">Line</span> {
        <span class="macro">assert!</span>(<span class="ident">width</span> <span class="op">&gt;</span><span class="op">=</span> <span class="ident">Distance::ZERO</span>);
        <span class="kw">let</span> <span class="ident">angle</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">angle</span>().<span class="ident">rotate_degs</span>(<span class="number">90.0</span>);
        <span class="ident">Line::must_new</span>(
            <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">project_away</span>(<span class="ident">width</span>, <span class="ident">angle</span>),
            <span class="self">self</span>.<span class="ident">pt2</span>().<span class="ident">project_away</span>(<span class="ident">width</span>, <span class="ident">angle</span>),
        )
    }

    <span class="doccomment">/// Perpendicularly shifts the line over to the left. Width must be non-negative.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">shift_left</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">width</span>: <span class="ident">Distance</span>) -&gt; <span class="ident">Line</span> {
        <span class="macro">assert!</span>(<span class="ident">width</span> <span class="op">&gt;</span><span class="op">=</span> <span class="ident">Distance::ZERO</span>);
        <span class="kw">let</span> <span class="ident">angle</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">angle</span>().<span class="ident">rotate_degs</span>(<span class="op">-</span><span class="number">90.0</span>);
        <span class="ident">Line::must_new</span>(
            <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">project_away</span>(<span class="ident">width</span>, <span class="ident">angle</span>),
            <span class="self">self</span>.<span class="ident">pt2</span>().<span class="ident">project_away</span>(<span class="ident">width</span>, <span class="ident">angle</span>),
        )
    }

    <span class="doccomment">/// Perpendicularly shifts the line to the right if positive or left if negative.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">shift_either_direction</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">width</span>: <span class="ident">Distance</span>) -&gt; <span class="ident">Line</span> {
        <span class="kw">if</span> <span class="ident">width</span> <span class="op">&gt;</span><span class="op">=</span> <span class="ident">Distance::ZERO</span> {
            <span class="self">self</span>.<span class="ident">shift_right</span>(<span class="ident">width</span>)
        } <span class="kw">else</span> {
            <span class="self">self</span>.<span class="ident">shift_left</span>(<span class="op">-</span><span class="ident">width</span>)
        }
    }

    <span class="doccomment">/// Returns a reversed line segment</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">reversed</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">Line</span> {
        <span class="ident">Line::must_new</span>(<span class="self">self</span>.<span class="ident">pt2</span>(), <span class="self">self</span>.<span class="ident">pt1</span>())
    }

    <span class="doccomment">/// The angle of the line segment, from the first to the second point</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">angle</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="ident">Angle</span> {
        <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">angle_to</span>(<span class="self">self</span>.<span class="ident">pt2</span>())
    }

    <span class="doccomment">/// Returns a point along the line segment, unless the distance exceeds the segment&#39;s length.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">dist_along</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">dist</span>: <span class="ident">Distance</span>) -&gt; <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">Pt2D</span><span class="op">&gt;</span> {
        <span class="kw">let</span> <span class="ident">len</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">length</span>();
        <span class="kw">if</span> <span class="ident">dist</span> <span class="op">&lt;</span> <span class="ident">Distance::ZERO</span> <span class="op">|</span><span class="op">|</span> <span class="ident">dist</span> <span class="op">&gt;</span> <span class="ident">len</span> {
            <span class="macro">bail!</span>(<span class="string">&quot;dist_along({}) of a length {} line&quot;</span>, <span class="ident">dist</span>, <span class="ident">len</span>);
        }
        <span class="self">self</span>.<span class="ident">percent_along</span>(<span class="ident">dist</span> <span class="op">/</span> <span class="ident">len</span>)
    }
    <span class="doccomment">/// Equivalent to `self.dist_along(dist).unwrap()`. Use this to document an assertion at the</span>
    <span class="doccomment">/// call-site.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">must_dist_along</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">dist</span>: <span class="ident">Distance</span>) -&gt; <span class="ident">Pt2D</span> {
        <span class="self">self</span>.<span class="ident">dist_along</span>(<span class="ident">dist</span>).<span class="ident">unwrap</span>()
    }

    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">unbounded_dist_along</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">dist</span>: <span class="ident">Distance</span>) -&gt; <span class="ident">Pt2D</span> {
        <span class="self">self</span>.<span class="ident">unbounded_percent_along</span>(<span class="ident">dist</span> <span class="op">/</span> <span class="self">self</span>.<span class="ident">length</span>())
    }

    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">unbounded_percent_along</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">percent</span>: <span class="ident">f64</span>) -&gt; <span class="ident">Pt2D</span> {
        <span class="ident">Pt2D::new</span>(
            <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">x</span>() <span class="op">+</span> <span class="ident">percent</span> <span class="op">*</span> (<span class="self">self</span>.<span class="ident">pt2</span>().<span class="ident">x</span>() <span class="op">-</span> <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">x</span>()),
            <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">y</span>() <span class="op">+</span> <span class="ident">percent</span> <span class="op">*</span> (<span class="self">self</span>.<span class="ident">pt2</span>().<span class="ident">y</span>() <span class="op">-</span> <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">y</span>()),
        )
    }
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">percent_along</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">percent</span>: <span class="ident">f64</span>) -&gt; <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">Pt2D</span><span class="op">&gt;</span> {
        <span class="kw">if</span> <span class="op">!</span>(<span class="number">0.0</span>..<span class="op">=</span><span class="number">1.0</span>).<span class="ident">contains</span>(<span class="kw-2">&amp;</span><span class="ident">percent</span>) {
            <span class="macro">bail!</span>(<span class="string">&quot;percent_along({}) of some line outside [0, 1]&quot;</span>, <span class="ident">percent</span>);
        }
        <span class="prelude-val">Ok</span>(<span class="self">self</span>.<span class="ident">unbounded_percent_along</span>(<span class="ident">percent</span>))
    }

    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">slice</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">from</span>: <span class="ident">Distance</span>, <span class="ident">to</span>: <span class="ident">Distance</span>) -&gt; <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">Line</span><span class="op">&gt;</span> {
        <span class="kw">if</span> <span class="ident">from</span> <span class="op">&lt;</span> <span class="ident">Distance::ZERO</span> <span class="op">|</span><span class="op">|</span> <span class="ident">to</span> <span class="op">&lt;</span> <span class="ident">Distance::ZERO</span> <span class="op">|</span><span class="op">|</span> <span class="ident">from</span> <span class="op">&gt;</span><span class="op">=</span> <span class="ident">to</span> {
            <span class="macro">bail!</span>(<span class="string">&quot;slice({}, {}) makes no sense&quot;</span>, <span class="ident">from</span>, <span class="ident">to</span>);
        }
        <span class="ident">Line::new</span>(<span class="self">self</span>.<span class="ident">dist_along</span>(<span class="ident">from</span>)<span class="question-mark">?</span>, <span class="self">self</span>.<span class="ident">dist_along</span>(<span class="ident">to</span>)<span class="question-mark">?</span>)
    }

    <span class="doccomment">/// Returns a subset of this line, with two percentages along the line&#39;s length.</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">percent_slice</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">from</span>: <span class="ident">f64</span>, <span class="ident">to</span>: <span class="ident">f64</span>) -&gt; <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">Line</span><span class="op">&gt;</span> {
        <span class="self">self</span>.<span class="ident">slice</span>(<span class="ident">from</span> <span class="op">*</span> <span class="self">self</span>.<span class="ident">length</span>(), <span class="ident">to</span> <span class="op">*</span> <span class="self">self</span>.<span class="ident">length</span>())
    }

    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">middle</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">Pt2D</span><span class="op">&gt;</span> {
        <span class="self">self</span>.<span class="ident">dist_along</span>(<span class="self">self</span>.<span class="ident">length</span>() <span class="op">/</span> <span class="number">2.0</span>)
    }

    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">contains_pt</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">pt</span>: <span class="ident">Pt2D</span>) -&gt; <span class="ident">bool</span> {
        <span class="self">self</span>.<span class="ident">dist_along_of_point</span>(<span class="ident">pt</span>).<span class="ident">is_some</span>()
    }

    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">dist_along_of_point</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">pt</span>: <span class="ident">Pt2D</span>) -&gt; <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">Distance</span><span class="op">&gt;</span> {
        <span class="kw">let</span> <span class="ident">dist1</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">raw_dist_to</span>(<span class="ident">pt</span>);
        <span class="kw">let</span> <span class="ident">dist2</span> <span class="op">=</span> <span class="ident">pt</span>.<span class="ident">raw_dist_to</span>(<span class="self">self</span>.<span class="ident">pt2</span>());
        <span class="kw">let</span> <span class="ident">length</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">pt1</span>().<span class="ident">raw_dist_to</span>(<span class="self">self</span>.<span class="ident">pt2</span>());
        <span class="kw">if</span> (<span class="ident">dist1</span> <span class="op">+</span> <span class="ident">dist2</span> <span class="op">-</span> <span class="ident">length</span>).<span class="ident">abs</span>() <span class="op">&lt;</span> <span class="ident">EPSILON_DIST</span>.<span class="ident">inner_meters</span>() {
            <span class="prelude-val">Some</span>(<span class="ident">Distance::meters</span>(<span class="ident">dist1</span>))
        } <span class="kw">else</span> {
            <span class="prelude-val">None</span>
        }
    }
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">percent_along_of_point</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">pt</span>: <span class="ident">Pt2D</span>) -&gt; <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">f64</span><span class="op">&gt;</span> {
        <span class="kw">let</span> <span class="ident">dist</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">dist_along_of_point</span>(<span class="ident">pt</span>)<span class="question-mark">?</span>;
        <span class="prelude-val">Some</span>(<span class="ident">dist</span> <span class="op">/</span> <span class="self">self</span>.<span class="ident">length</span>())
    }
}

<span class="kw">impl</span> <span class="ident">fmt::Display</span> <span class="kw">for</span> <span class="ident">Line</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">writeln!</span>(<span class="ident">f</span>, <span class="string">&quot;Line::new(&quot;</span>)<span class="question-mark">?</span>;
        <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">&quot;  Pt2D::new({}, {}),&quot;</span>, <span class="self">self</span>.<span class="number">0</span>.<span class="ident">x</span>(), <span class="self">self</span>.<span class="number">0</span>.<span class="ident">y</span>())<span class="question-mark">?</span>;
        <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">&quot;  Pt2D::new({}, {}),&quot;</span>, <span class="self">self</span>.<span class="number">1</span>.<span class="ident">x</span>(), <span class="self">self</span>.<span class="number">1</span>.<span class="ident">y</span>())<span class="question-mark">?</span>;
        <span class="macro">write!</span>(<span class="ident">f</span>, <span class="string">&quot;)&quot;</span>)
    }
}

<span class="kw">fn</span> <span class="ident">is_counter_clockwise</span>(<span class="ident">pt1</span>: <span class="ident">Pt2D</span>, <span class="ident">pt2</span>: <span class="ident">Pt2D</span>, <span class="ident">pt3</span>: <span class="ident">Pt2D</span>) -&gt; <span class="ident">bool</span> {
    (<span class="ident">pt3</span>.<span class="ident">y</span>() <span class="op">-</span> <span class="ident">pt1</span>.<span class="ident">y</span>()) <span class="op">*</span> (<span class="ident">pt2</span>.<span class="ident">x</span>() <span class="op">-</span> <span class="ident">pt1</span>.<span class="ident">x</span>()) <span class="op">&gt;</span> (<span class="ident">pt2</span>.<span class="ident">y</span>() <span class="op">-</span> <span class="ident">pt1</span>.<span class="ident">y</span>()) <span class="op">*</span> (<span class="ident">pt3</span>.<span class="ident">x</span>() <span class="op">-</span> <span class="ident">pt1</span>.<span class="ident">x</span>())
}

<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Serialize</span>, <span class="ident">Deserialize</span>, <span class="ident">Debug</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">InfiniteLine</span>(<span class="ident">Pt2D</span>, <span class="ident">Pt2D</span>);

<span class="kw">impl</span> <span class="ident">InfiniteLine</span> {
    <span class="doccomment">/// Fails for parallel lines.</span>
    <span class="comment">// https://stackoverflow.com/a/565282 by way of</span>
    <span class="comment">// https://github.com/ucarion/line_intersection/blob/master/src/lib.rs</span>
    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">intersection</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">other</span>: <span class="kw-2">&amp;</span><span class="ident">InfiniteLine</span>) -&gt; <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">Pt2D</span><span class="op">&gt;</span> {
        <span class="attribute">#![<span class="ident">allow</span>(<span class="ident">clippy::many_single_char_names</span>)]</span>
        <span class="kw">fn</span> <span class="ident">cross</span>(<span class="ident">a</span>: (<span class="ident">f64</span>, <span class="ident">f64</span>), <span class="ident">b</span>: (<span class="ident">f64</span>, <span class="ident">f64</span>)) -&gt; <span class="ident">f64</span> {
            <span class="ident">a</span>.<span class="number">0</span> <span class="op">*</span> <span class="ident">b</span>.<span class="number">1</span> <span class="op">-</span> <span class="ident">a</span>.<span class="number">1</span> <span class="op">*</span> <span class="ident">b</span>.<span class="number">0</span>
        }

        <span class="kw">let</span> <span class="ident">p</span> <span class="op">=</span> <span class="self">self</span>.<span class="number">0</span>;
        <span class="kw">let</span> <span class="ident">q</span> <span class="op">=</span> <span class="ident">other</span>.<span class="number">0</span>;
        <span class="kw">let</span> <span class="ident">r</span> <span class="op">=</span> (<span class="self">self</span>.<span class="number">1</span>.<span class="ident">x</span>() <span class="op">-</span> <span class="self">self</span>.<span class="number">0</span>.<span class="ident">x</span>(), <span class="self">self</span>.<span class="number">1</span>.<span class="ident">y</span>() <span class="op">-</span> <span class="self">self</span>.<span class="number">0</span>.<span class="ident">y</span>());
        <span class="kw">let</span> <span class="ident">s</span> <span class="op">=</span> (<span class="ident">other</span>.<span class="number">1</span>.<span class="ident">x</span>() <span class="op">-</span> <span class="ident">other</span>.<span class="number">0</span>.<span class="ident">x</span>(), <span class="ident">other</span>.<span class="number">1</span>.<span class="ident">y</span>() <span class="op">-</span> <span class="ident">other</span>.<span class="number">0</span>.<span class="ident">y</span>());

        <span class="kw">let</span> <span class="ident">r_cross_s</span> <span class="op">=</span> <span class="ident">cross</span>(<span class="ident">r</span>, <span class="ident">s</span>);
        <span class="kw">let</span> <span class="ident">q_minus_p</span> <span class="op">=</span> (<span class="ident">q</span>.<span class="ident">x</span>() <span class="op">-</span> <span class="ident">p</span>.<span class="ident">x</span>(), <span class="ident">q</span>.<span class="ident">y</span>() <span class="op">-</span> <span class="ident">p</span>.<span class="ident">y</span>());
        <span class="comment">//let q_minus_p_cross_r = cross(q_minus_p, r);</span>

        <span class="kw">if</span> <span class="ident">r_cross_s</span> <span class="op">==</span> <span class="number">0.0</span> {
            <span class="comment">// Parallel</span>
            <span class="prelude-val">None</span>
        } <span class="kw">else</span> {
            <span class="kw">let</span> <span class="ident">t</span> <span class="op">=</span> <span class="ident">cross</span>(<span class="ident">q_minus_p</span>, (<span class="ident">s</span>.<span class="number">0</span> <span class="op">/</span> <span class="ident">r_cross_s</span>, <span class="ident">s</span>.<span class="number">1</span> <span class="op">/</span> <span class="ident">r_cross_s</span>));
            <span class="comment">//let u = cross(q_minus_p, Pt2D::new(r.x() / r_cross_s, r.y() / r_cross_s));</span>
            <span class="prelude-val">Some</span>(<span class="ident">Pt2D::new</span>(<span class="ident">p</span>.<span class="ident">x</span>() <span class="op">+</span> <span class="ident">t</span> <span class="op">*</span> <span class="ident">r</span>.<span class="number">0</span>, <span class="ident">p</span>.<span class="ident">y</span>() <span class="op">+</span> <span class="ident">t</span> <span class="op">*</span> <span class="ident">r</span>.<span class="number">1</span>))
        }
    }

    <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">from_pt_angle</span>(<span class="ident">pt</span>: <span class="ident">Pt2D</span>, <span class="ident">angle</span>: <span class="ident">Angle</span>) -&gt; <span class="ident">InfiniteLine</span> {
        <span class="ident">Line::must_new</span>(<span class="ident">pt</span>, <span class="ident">pt</span>.<span class="ident">project_away</span>(<span class="ident">Distance::meters</span>(<span class="number">1.0</span>), <span class="ident">angle</span>)).<span class="ident">infinite</span>()
    }
}

<span class="kw">impl</span> <span class="ident">fmt::Display</span> <span class="kw">for</span> <span class="ident">InfiniteLine</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">writeln!</span>(<span class="ident">f</span>, <span class="string">&quot;InfiniteLine::new(&quot;</span>)<span class="question-mark">?</span>;
        <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">&quot;  Pt2D::new({}, {}),&quot;</span>, <span class="self">self</span>.<span class="number">0</span>.<span class="ident">x</span>(), <span class="self">self</span>.<span class="number">0</span>.<span class="ident">y</span>())<span class="question-mark">?</span>;
        <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">&quot;  Pt2D::new({}, {}),&quot;</span>, <span class="self">self</span>.<span class="number">1</span>.<span class="ident">x</span>(), <span class="self">self</span>.<span class="number">1</span>.<span class="ident">y</span>())<span class="question-mark">?</span>;
        <span class="macro">write!</span>(<span class="ident">f</span>, <span class="string">&quot;)&quot;</span>)
    }
}
</code></pre></div>
</section><section id="search" class="content hidden"></section><div id="rustdoc-vars" data-root-path="../../" data-current-crate="geom" data-search-index-js="../../search-index.js" data-search-js="../../search.js"></div>
</body></html>