<!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/src/gps.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>gps.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="mobile-topbar"><button class="sidebar-menu-toggle">☰</button><a class="sidebar-logo" href="../../geom/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div> </a><h2 class="location"></h2> </nav> <nav class="sidebar"><a class="sidebar-logo" href="../../geom/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" 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.svg" alt="logo"></a><nav class="sub"><div class="theme-picker hidden"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu" title="themes"><img width="22" height="22" alt="Pick another theme!" src="../../brush.svg"></button><div id="theme-choices" role="menu"></div></div><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><button type="button" id="help-button" title="help">?</button><a id="settings-menu" href="../../settings.html" title="settings"><img width="22" height="22" 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> <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> </pre><pre class="rust"><code><span class="kw">use</span> <span class="ident">std::fmt</span>; <span class="kw">use</span> <span class="ident">std::io</span>::{<span class="ident">BufRead</span>, <span class="ident">BufReader</span>, <span class="ident">Write</span>}; <span class="kw">use</span> <span class="ident">anyhow::Result</span>; <span class="kw">use</span> <span class="ident">fs_err::File</span>; <span class="kw">use</span> <span class="ident">geojson</span>::{<span class="ident">GeoJson</span>, <span class="ident">Value</span>}; <span class="kw">use</span> <span class="ident">ordered_float::NotNan</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">Distance</span>, <span class="ident">GPSBounds</span>, <span class="ident">Pt2D</span>}; <span class="doccomment">/// Represents a (longitude, latitude) point.</span> <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Copy</span>, <span class="ident">Clone</span>, <span class="ident">PartialEq</span>, <span class="ident">Eq</span>, <span class="ident">PartialOrd</span>, <span class="ident">Ord</span>, <span class="ident">Debug</span>, <span class="ident">Serialize</span>, <span class="ident">Deserialize</span>)]</span> <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">LonLat</span> { <span class="ident">longitude</span>: <span class="ident">NotNan</span><span class="op"><</span><span class="ident">f64</span><span class="op">></span>, <span class="ident">latitude</span>: <span class="ident">NotNan</span><span class="op"><</span><span class="ident">f64</span><span class="op">></span>, } <span class="kw">impl</span> <span class="ident">LonLat</span> { <span class="doccomment">/// Note the order of arguments!</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">lon</span>: <span class="ident">f64</span>, <span class="ident">lat</span>: <span class="ident">f64</span>) -> <span class="ident">LonLat</span> { <span class="ident">LonLat</span> { <span class="ident">longitude</span>: <span class="ident">NotNan::new</span>(<span class="ident">lon</span>).<span class="ident">unwrap</span>(), <span class="ident">latitude</span>: <span class="ident">NotNan::new</span>(<span class="ident">lat</span>).<span class="ident">unwrap</span>(), } } <span class="doccomment">/// Returns the longitude of this point.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">x</span>(<span class="self">self</span>) -> <span class="ident">f64</span> { <span class="self">self</span>.<span class="ident">longitude</span>.<span class="ident">into_inner</span>() } <span class="doccomment">/// Returns the latitude of this point.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">y</span>(<span class="self">self</span>) -> <span class="ident">f64</span> { <span class="self">self</span>.<span class="ident">latitude</span>.<span class="ident">into_inner</span>() } <span class="doccomment">/// Transform this to a world-space point. Can go out of bounds.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">to_pt</span>(<span class="self">self</span>, <span class="ident">b</span>: <span class="kw-2">&</span><span class="ident">GPSBounds</span>) -> <span class="ident">Pt2D</span> { <span class="kw">let</span> (<span class="ident">width</span>, <span class="ident">height</span>) <span class="op">=</span> { <span class="kw">let</span> <span class="ident">pt</span> <span class="op">=</span> <span class="ident">b</span>.<span class="ident">get_max_world_pt</span>(); (<span class="ident">pt</span>.<span class="ident">x</span>(), <span class="ident">pt</span>.<span class="ident">y</span>()) }; <span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> (<span class="self">self</span>.<span class="ident">x</span>() <span class="op">-</span> <span class="ident">b</span>.<span class="ident">min_lon</span>) <span class="op">/</span> (<span class="ident">b</span>.<span class="ident">max_lon</span> <span class="op">-</span> <span class="ident">b</span>.<span class="ident">min_lon</span>) <span class="op">*</span> <span class="ident">width</span>; <span class="comment">// Invert y, so that the northernmost latitude is 0. Screen drawing order, not Cartesian</span> <span class="comment">// grid.</span> <span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="ident">height</span> <span class="op">-</span> ((<span class="self">self</span>.<span class="ident">y</span>() <span class="op">-</span> <span class="ident">b</span>.<span class="ident">min_lat</span>) <span class="op">/</span> (<span class="ident">b</span>.<span class="ident">max_lat</span> <span class="op">-</span> <span class="ident">b</span>.<span class="ident">min_lat</span>) <span class="op">*</span> <span class="ident">height</span>); <span class="ident">Pt2D::new</span>(<span class="ident">x</span>, <span class="ident">y</span>) } <span class="doccomment">/// Returns the Haversine distance to another point.</span> <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn</span> <span class="ident">gps_dist</span>(<span class="self">self</span>, <span class="ident">other</span>: <span class="ident">LonLat</span>) -> <span class="ident">Distance</span> { <span class="kw">let</span> <span class="ident">earth_radius_m</span> <span class="op">=</span> <span class="number">6_371_000.0</span>; <span class="kw">let</span> <span class="ident">lon1</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">x</span>().<span class="ident">to_radians</span>(); <span class="kw">let</span> <span class="ident">lon2</span> <span class="op">=</span> <span class="ident">other</span>.<span class="ident">x</span>().<span class="ident">to_radians</span>(); <span class="kw">let</span> <span class="ident">lat1</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">y</span>().<span class="ident">to_radians</span>(); <span class="kw">let</span> <span class="ident">lat2</span> <span class="op">=</span> <span class="ident">other</span>.<span class="ident">y</span>().<span class="ident">to_radians</span>(); <span class="kw">let</span> <span class="ident">delta_lat</span> <span class="op">=</span> <span class="ident">lat2</span> <span class="op">-</span> <span class="ident">lat1</span>; <span class="kw">let</span> <span class="ident">delta_lon</span> <span class="op">=</span> <span class="ident">lon2</span> <span class="op">-</span> <span class="ident">lon1</span>; <span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> (<span class="ident">delta_lat</span> <span class="op">/</span> <span class="number">2.0</span>).<span class="ident">sin</span>().<span class="ident">powi</span>(<span class="number">2</span>) <span class="op">+</span> (<span class="ident">delta_lon</span> <span class="op">/</span> <span class="number">2.0</span>).<span class="ident">sin</span>().<span class="ident">powi</span>(<span class="number">2</span>) <span class="op">*</span> <span class="ident">lat1</span>.<span class="ident">cos</span>() <span class="op">*</span> <span class="ident">lat2</span>.<span class="ident">cos</span>(); <span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="number">2.0</span> <span class="op">*</span> <span class="ident">a</span>.<span class="ident">sqrt</span>().<span class="ident">atan2</span>((<span class="number">1.0</span> <span class="op">-</span> <span class="ident">a</span>).<span class="ident">sqrt</span>()); <span class="ident">Distance::meters</span>(<span class="ident">earth_radius_m</span> <span class="op">*</span> <span class="ident">c</span>) } <span class="doccomment">/// Pretty meaningless units, for comparing distances very roughly</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">fast_dist</span>(<span class="self">self</span>, <span class="ident">other</span>: <span class="ident">LonLat</span>) -> <span class="ident">NotNan</span><span class="op"><</span><span class="ident">f64</span><span class="op">></span> { <span class="ident">NotNan::new</span>((<span class="self">self</span>.<span class="ident">x</span>() <span class="op">-</span> <span class="ident">other</span>.<span class="ident">x</span>()).<span class="ident">powi</span>(<span class="number">2</span>) <span class="op">+</span> (<span class="self">self</span>.<span class="ident">y</span>() <span class="op">-</span> <span class="ident">other</span>.<span class="ident">y</span>()).<span class="ident">powi</span>(<span class="number">2</span>)).<span class="ident">unwrap</span>() } <span class="doccomment">/// Parses a file in the https://wiki.openstreetmap.org/wiki/Osmosis/Polygon_Filter_File_Format</span> <span class="doccomment">/// and returns all points.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">read_osmosis_polygon</span>(<span class="ident">path</span>: <span class="kw-2">&</span><span class="ident">str</span>) -> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">Vec</span><span class="op"><</span><span class="ident">LonLat</span><span class="op">></span><span class="op">></span> { <span class="kw">let</span> <span class="ident">f</span> <span class="op">=</span> <span class="ident">File::open</span>(<span class="ident">path</span>)<span class="question-mark">?</span>; <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">pts</span> <span class="op">=</span> <span class="ident">Vec::new</span>(); <span class="kw">for</span> (<span class="ident">idx</span>, <span class="ident">line</span>) <span class="kw">in</span> <span class="ident">BufReader::new</span>(<span class="ident">f</span>).<span class="ident">lines</span>().<span class="ident">enumerate</span>() { <span class="kw">if</span> <span class="ident">idx</span> <span class="op"><</span> <span class="number">2</span> { <span class="kw">continue</span>; } <span class="kw">let</span> <span class="ident">line</span> <span class="op">=</span> <span class="ident">line</span><span class="question-mark">?</span>; <span class="kw">if</span> <span class="ident">line</span> <span class="op">==</span> <span class="string">"END"</span> { <span class="kw">break</span>; } <span class="kw">let</span> <span class="ident">parts</span> <span class="op">=</span> <span class="ident">line</span>.<span class="ident">trim</span>().<span class="ident">split</span>(<span class="string">" "</span>).<span class="ident">collect</span>::<span class="op"><</span><span class="ident">Vec</span><span class="op"><</span><span class="kw">_</span><span class="op">></span><span class="op">></span>(); <span class="ident">pts</span>.<span class="ident">push</span>(<span class="ident">LonLat::new</span>( <span class="ident">parts</span>[<span class="number">0</span>].<span class="ident">parse</span>::<span class="op"><</span><span class="ident">f64</span><span class="op">></span>()<span class="question-mark">?</span>, <span class="ident">parts</span>[<span class="number">1</span>].<span class="ident">parse</span>::<span class="op"><</span><span class="ident">f64</span><span class="op">></span>()<span class="question-mark">?</span>, )); } <span class="prelude-val">Ok</span>(<span class="ident">pts</span>) } <span class="doccomment">/// Writes a set of points to a file in the</span> <span class="doccomment">/// https://wiki.openstreetmap.org/wiki/Osmosis/Polygon_Filter_File_Format. The input should</span> <span class="doccomment">/// be a closed ring, with the first and last point matching.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">write_osmosis_polygon</span>(<span class="ident">path</span>: <span class="kw-2">&</span><span class="ident">str</span>, <span class="ident">pts</span>: <span class="kw-2">&</span>[<span class="ident">LonLat</span>]) -> <span class="prelude-ty">Result</span><span class="op"><</span>()<span class="op">></span> { <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">f</span> <span class="op">=</span> <span class="ident">File::create</span>(<span class="ident">path</span>)<span class="question-mark">?</span>; <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">"boundary"</span>)<span class="question-mark">?</span>; <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">"1"</span>)<span class="question-mark">?</span>; <span class="kw">for</span> <span class="ident">pt</span> <span class="kw">in</span> <span class="ident">pts</span> { <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">" {} {}"</span>, <span class="ident">pt</span>.<span class="ident">x</span>(), <span class="ident">pt</span>.<span class="ident">y</span>())<span class="question-mark">?</span>; } <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">"END"</span>)<span class="question-mark">?</span>; <span class="macro">writeln!</span>(<span class="ident">f</span>, <span class="string">"END"</span>)<span class="question-mark">?</span>; <span class="prelude-val">Ok</span>(()) } <span class="doccomment">/// Finds the average of a set of coordinates.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">center</span>(<span class="ident">pts</span>: <span class="kw-2">&</span>[<span class="ident">LonLat</span>]) -> <span class="ident">LonLat</span> { <span class="kw">if</span> <span class="ident">pts</span>.<span class="ident">is_empty</span>() { <span class="macro">panic!</span>(<span class="string">"Can't find center of 0 points"</span>); } <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</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">y</span> <span class="op">=</span> <span class="number">0.0</span>; <span class="kw">for</span> <span class="ident">pt</span> <span class="kw">in</span> <span class="ident">pts</span> { <span class="ident">x</span> <span class="op">+</span><span class="op">=</span> <span class="ident">pt</span>.<span class="ident">x</span>(); <span class="ident">y</span> <span class="op">+</span><span class="op">=</span> <span class="ident">pt</span>.<span class="ident">y</span>(); } <span class="kw">let</span> <span class="ident">len</span> <span class="op">=</span> <span class="ident">pts</span>.<span class="ident">len</span>() <span class="kw">as</span> <span class="ident">f64</span>; <span class="ident">LonLat::new</span>(<span class="ident">x</span> <span class="op">/</span> <span class="ident">len</span>, <span class="ident">y</span> <span class="op">/</span> <span class="ident">len</span>) } <span class="doccomment">/// Parses a WKT-style line-string into a list of coordinates.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">parse_wkt_linestring</span>(<span class="ident">raw</span>: <span class="kw-2">&</span><span class="ident">str</span>) -> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">Vec</span><span class="op"><</span><span class="ident">LonLat</span><span class="op">></span><span class="op">></span> { <span class="comment">// Input is something like LINESTRING (-111.9263026 33.4245036, -111.9275146 33.4245016,</span> <span class="comment">// -111.9278751 33.4233106)</span> <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">pts</span> <span class="op">=</span> <span class="ident">Vec::new</span>(); <span class="comment">// -111.9446 33.425474, -111.9442814 33.4254737, -111.9442762 33.426894</span> <span class="kw">for</span> <span class="ident">pair</span> <span class="kw">in</span> <span class="ident">raw</span> .<span class="ident">strip_prefix</span>(<span class="string">"LINESTRING ("</span>)<span class="question-mark">?</span> .<span class="ident">strip_suffix</span>(<span class="string">')'</span>)<span class="question-mark">?</span> .<span class="ident">split</span>(<span class="string">", "</span>) { <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">nums</span> <span class="op">=</span> <span class="ident">Vec::new</span>(); <span class="kw">for</span> <span class="ident">x</span> <span class="kw">in</span> <span class="ident">pair</span>.<span class="ident">split</span>(<span class="string">' '</span>) { <span class="ident">nums</span>.<span class="ident">push</span>(<span class="ident">x</span>.<span class="ident">parse</span>::<span class="op"><</span><span class="ident">f64</span><span class="op">></span>().<span class="ident">ok</span>()<span class="question-mark">?</span>); } <span class="kw">if</span> <span class="ident">nums</span>.<span class="ident">len</span>() <span class="op">!</span><span class="op">=</span> <span class="number">2</span> { <span class="kw">return</span> <span class="prelude-val">None</span>; } <span class="ident">pts</span>.<span class="ident">push</span>(<span class="ident">LonLat::new</span>(<span class="ident">nums</span>[<span class="number">0</span>], <span class="ident">nums</span>[<span class="number">1</span>])); } <span class="kw">if</span> <span class="ident">pts</span>.<span class="ident">len</span>() <span class="op"><</span> <span class="number">2</span> { <span class="kw">return</span> <span class="prelude-val">None</span>; } <span class="prelude-val">Some</span>(<span class="ident">pts</span>) } <span class="doccomment">/// Extract polygons from a raw GeoJSON string. For multipolygons, only returns the first</span> <span class="doccomment">/// member. If the GeoJSON feature has a property called `name`, this will also be returned.</span> <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">parse_geojson_polygons</span>(<span class="ident">raw</span>: <span class="ident">String</span>) -> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">Vec</span><span class="op"><</span>(<span class="ident">Vec</span><span class="op"><</span><span class="ident">LonLat</span><span class="op">></span>, <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">String</span><span class="op">></span>)<span class="op">></span><span class="op">></span> { <span class="kw">let</span> <span class="ident">geojson</span> <span class="op">=</span> <span class="ident">raw</span>.<span class="ident">parse</span>::<span class="op"><</span><span class="ident">GeoJson</span><span class="op">></span>()<span class="question-mark">?</span>; <span class="kw">let</span> <span class="ident">features</span> <span class="op">=</span> <span class="kw">match</span> <span class="ident">geojson</span> { <span class="ident">GeoJson::Feature</span>(<span class="ident">feature</span>) => <span class="macro">vec!</span>[<span class="ident">feature</span>], <span class="ident">GeoJson::FeatureCollection</span>(<span class="ident">feature_collection</span>) => <span class="ident">feature_collection</span>.<span class="ident">features</span>, <span class="kw">_</span> => <span class="macro">anyhow::bail!</span>(<span class="string">"Unexpected geojson: {:?}"</span>, <span class="ident">geojson</span>), }; <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">polygons</span> <span class="op">=</span> <span class="ident">Vec::new</span>(); <span class="kw">for</span> <span class="kw-2">mut</span> <span class="ident">feature</span> <span class="kw">in</span> <span class="ident">features</span> { <span class="kw">let</span> <span class="ident">points</span> <span class="op">=</span> <span class="kw">match</span> <span class="ident">feature</span>.<span class="ident">geometry</span>.<span class="ident">take</span>().<span class="ident">map</span>(<span class="op">|</span><span class="ident">g</span><span class="op">|</span> <span class="ident">g</span>.<span class="ident">value</span>) { <span class="prelude-val">Some</span>(<span class="ident">Value::MultiPolygon</span>(<span class="ident">multi_polygon</span>)) => <span class="ident">multi_polygon</span>[<span class="number">0</span>][<span class="number">0</span>].<span class="ident">clone</span>(), <span class="prelude-val">Some</span>(<span class="ident">Value::Polygon</span>(<span class="ident">polygon</span>)) => <span class="ident">polygon</span>[<span class="number">0</span>].<span class="ident">clone</span>(), <span class="kw">_</span> => { <span class="macro">anyhow::bail!</span>(<span class="string">"Unexpected feature: {:?}"</span>, <span class="ident">feature</span>); } }; <span class="kw">let</span> <span class="ident">name</span> <span class="op">=</span> <span class="ident">feature</span> .<span class="ident">property</span>(<span class="string">"name"</span>) .<span class="ident">and_then</span>(<span class="op">|</span><span class="ident">value</span><span class="op">|</span> <span class="ident">value</span>.<span class="ident">as_str</span>()) .<span class="ident">map</span>(<span class="op">|</span><span class="ident">x</span><span class="op">|</span> <span class="ident">x</span>.<span class="ident">to_string</span>()); <span class="ident">polygons</span>.<span class="ident">push</span>(( <span class="ident">points</span> .<span class="ident">into_iter</span>() .<span class="ident">map</span>(<span class="op">|</span><span class="ident">pt</span><span class="op">|</span> <span class="ident">LonLat::new</span>(<span class="ident">pt</span>[<span class="number">0</span>], <span class="ident">pt</span>[<span class="number">1</span>])) .<span class="ident">collect</span>(), <span class="ident">name</span>, )); } <span class="prelude-val">Ok</span>(<span class="ident">polygons</span>) } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">to_geojson</span>(<span class="self">self</span>) -> <span class="ident">geojson::Geometry</span> { <span class="ident">geojson::Geometry::new</span>(<span class="ident">geojson::Value::Point</span>(<span class="macro">vec!</span>[<span class="self">self</span>.<span class="ident">x</span>(), <span class="self">self</span>.<span class="ident">y</span>()])) } } <span class="kw">impl</span> <span class="ident">fmt::Display</span> <span class="kw">for</span> <span class="ident">LonLat</span> { <span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&mut</span> <span class="ident">fmt::Formatter</span>) -> <span class="ident">fmt::Result</span> { <span class="macro">write!</span>(<span class="ident">f</span>, <span class="string">"LonLat({0}, {1})"</span>, <span class="self">self</span>.<span class="ident">x</span>(), <span class="self">self</span>.<span class="ident">y</span>()) } } <span class="kw">impl</span> <span class="ident">From</span><span class="op"><</span><span class="ident">LonLat</span><span class="op">></span> <span class="kw">for</span> <span class="ident">geo::Point</span> { <span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">pt</span>: <span class="ident">LonLat</span>) -> <span class="self">Self</span> { <span class="ident">geo::Point::new</span>(<span class="ident">pt</span>.<span class="ident">x</span>(), <span class="ident">pt</span>.<span class="ident">y</span>()) } } </code></pre></div> </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="1.62.1 (e092d0b6b 2022-07-16)" ></div> </body></html>