From 0feb28278844b4b80d91a070af3d8da2244b3142 Mon Sep 17 00:00:00 2001
From: Dustin Carlino <dabreegster@gmail.com>
Date: Wed, 16 Aug 2023 17:55:52 +0100
Subject: [PATCH] Add a layer for existing cycle paths. #299

---
 src/lib/browse/LayerControls.svelte           |   2 +
 src/lib/browse/colors.ts                      |   8 +
 .../layers/CyclePathsLayerControl.svelte      | 148 ++++++++++++++++++
 src/maplibre_helpers.ts                       |   6 +-
 4 files changed, 162 insertions(+), 2 deletions(-)
 create mode 100644 src/lib/browse/layers/CyclePathsLayerControl.svelte

diff --git a/src/lib/browse/LayerControls.svelte b/src/lib/browse/LayerControls.svelte
index d26ee7005..57fadefac 100644
--- a/src/lib/browse/LayerControls.svelte
+++ b/src/lib/browse/LayerControls.svelte
@@ -5,6 +5,7 @@
   import CensusOutputAreaLayerControl from "./layers/CensusOutputAreaLayerControl.svelte";
   import CombinedAuthoritiesLayerControl from "./layers/CombinedAuthoritiesLayerControl.svelte";
   import CycleParkingLayerControl from "./layers/CycleParkingLayerControl.svelte";
+  import CyclePathsLayerControl from "./layers/CyclePathsLayerControl.svelte";
   import HospitalsLayerControl from "./layers/HospitalsLayerControl.svelte";
   import ImdLayerControl from "./layers/ImdLayerControl.svelte";
   import LocalAuthorityDistrictsLayerControl from "./layers/LocalAuthorityDistrictsLayerControl.svelte";
@@ -30,6 +31,7 @@
   </CollapsibleCard>
   <CollapsibleCard label="Existing infrastructure">
     <CheckboxGroup small>
+      <CyclePathsLayerControl />
       <MrnLayerControl />
       <BusRoutesLayerControl />
       <CycleParkingLayerControl />
diff --git a/src/lib/browse/colors.ts b/src/lib/browse/colors.ts
index d15867ee3..5c63f922d 100644
--- a/src/lib/browse/colors.ts
+++ b/src/lib/browse/colors.ts
@@ -14,6 +14,14 @@ export const colors = {
   bus_route_without_lane: "#C2A6D8",
   cycle_parking: "black",
 
+  // Thanks to https://github.com/cyipt/cyipt-website/issues/23
+  cycle_paths: {
+    track: "#0000FF",
+    lane: "#009FEF",
+    shared_use_segregated: "#FF9900",
+    shared_use_unsegregated: "#E7E700",
+  },
+
   // Color ramp from https://www.ons.gov.uk/census/maps/choropleth
   sequential_low_to_high: [
     "#CDE594",
diff --git a/src/lib/browse/layers/CyclePathsLayerControl.svelte b/src/lib/browse/layers/CyclePathsLayerControl.svelte
new file mode 100644
index 000000000..8750ea211
--- /dev/null
+++ b/src/lib/browse/layers/CyclePathsLayerControl.svelte
@@ -0,0 +1,148 @@
+<script lang="ts">
+  import type { MapGeoJSONFeature } from "maplibre-gl";
+  import {
+    constructMatchExpression,
+    hoveredToggle,
+    overwriteLineLayer,
+    overwritePmtilesSource,
+  } from "../../../maplibre_helpers";
+  import { map } from "../../../stores";
+  import {
+    ColorLegend,
+    ExternalLink,
+    HelpButton,
+    InteractiveLayer,
+  } from "../../common";
+  import { Checkbox } from "../../govuk";
+  import { colors } from "../colors";
+
+  let name = "cycle_paths";
+
+  let legend = [
+    ["Separated tracks", colors.cycle_paths.track],
+    ["Unprotected lanes", colors.cycle_paths.lane],
+    ["Shared-use (segregated)", colors.cycle_paths.shared_use_segregated],
+    ["Shared-use (unsegregated)", colors.cycle_paths.shared_use_unsegregated],
+  ];
+
+  overwritePmtilesSource(
+    $map,
+    name,
+    `https://atip.uk/layers/v1/${name}.pmtiles`
+  );
+
+  overwriteLineLayer($map, {
+    id: name,
+    source: name,
+    sourceLayer: name,
+    color: constructMatchExpression(
+      ["get", "kind"],
+      {
+        track: colors.cycle_paths.track,
+        lane: colors.cycle_paths.lane,
+        shared_use_segregated: colors.cycle_paths.shared_use_segregated,
+        shared_use_unsegregated: colors.cycle_paths.shared_use_unsegregated,
+      },
+      "red"
+    ),
+    width: [
+      "interpolate",
+      ["exponential", 1.6],
+      ["zoom"],
+      3,
+      1.0,
+      7,
+      2.0,
+      18,
+      20.0,
+    ],
+    opacity: hoveredToggle(0.5, 1.0),
+  });
+
+  let show = false;
+
+  function tooltip(feature: MapGeoJSONFeature): string {
+    // @ts-ignore Write types for the feature properties
+    let kind = {
+      track: "Separated track",
+      lane: "Unprotected lane",
+      shared_use_segregated: "Shared-use (segregated)",
+      shared_use_unsegregated: "Shared-use (unsegregated)",
+    }[feature.properties.kind];
+    // @ts-ignore Write types for the feature properties
+    let direction = {
+      "one-way": "&uarr;",
+      "two-way": "&#8597;",
+      unknown: "",
+    }[feature.properties.direction];
+    let width =
+      feature.properties.width == "unknown"
+        ? "unknown"
+        : `${feature.properties.width} meters`;
+
+    let x = `<h2>${kind}</h2>`;
+    x += `<p>Direction: <b>${direction} ${feature.properties.direction}</b></p>`;
+    x += `<p>Width: <b>${width}</b></p>`;
+    return x;
+  }
+
+  function onClick(e: CustomEvent<MapGeoJSONFeature>) {
+    window.open(
+      `http://openstreetmap.org/way/${e.detail.properties.osm_id}`,
+      "_blank"
+    );
+  }
+</script>
+
+<Checkbox id={name} bind:checked={show}>
+  Cycle paths
+  <span slot="right">
+    <HelpButton>
+      <p>
+        This shows different types of cycle path, according to OpenStreetMap (as
+        of 15 August 2023).
+      </p>
+      <ul>
+        <li>
+          <b>Separated tracks</b>
+          include fully or partly segregated cycletracks alongside a carriageway,
+          stepped cycletracks, and tracks off the carriageway entirely. They're also
+          separated from foot traffic.
+        </li>
+        <li>
+          <b>Unprotected lanes</b>
+          are mandatory or advisory lanes on the carriageway, without any physical
+          protection. They do not included shared bus lanes.
+        </li>
+        <li>
+          <b>Shared-use</b>
+          paths are split between cycle and foot traffic, and are separated from
+          motor traffic somehow. There can be segregation between cyclists and pedestrians
+          or not.
+        </li>
+      </ul>
+      <p>
+        Note there are many known limitations with this layer. Data in
+        OpenStreetMap can be missing, mapped twice, or mapped incorrectly. Our
+        processing is also imperfect. You can click a segment to see full
+        OpenStreetMap data. Please do report issues with the classification or
+        data.
+      </p>
+      <p>
+        License: <ExternalLink href="https://www.openstreetmap.org/copyright">
+          Open Data Commons Open Database License
+        </ExternalLink>
+      </p>
+    </HelpButton>
+  </span>
+</Checkbox>
+{#if show}
+  {#each legend as [label, color]}
+    <div>
+      <ColorLegend {color} />
+      {label}
+    </div>
+  {/each}
+{/if}
+
+<InteractiveLayer layer={name} {tooltip} {show} clickable on:click={onClick} />
diff --git a/src/maplibre_helpers.ts b/src/maplibre_helpers.ts
index 2410b6d56..b2bd887cb 100644
--- a/src/maplibre_helpers.ts
+++ b/src/maplibre_helpers.ts
@@ -319,6 +319,7 @@ const layerZorder = [
   "bus_routes",
   "railway_stations",
   "cycle_parking",
+  "cycle_paths",
 
   // Polygons are bigger than lines, which're bigger than points. When geometry
   // overlaps, put the smaller thing on top
@@ -355,9 +356,10 @@ const layerZorder = [
   "route-lines",
   "route-polygons",
 
-  // Draw most things beneath text road labels. This is the only layer in this
-  // list generated by the MapTiler basemap we use.
+  // Draw most things beneath text road labels. These IDs come from the
+  // MapTiler basemap, and there are different ones for each basemap.
   "road_label",
+  "Road labels",
 
   // Draw the inverted boundary fade on top of basemap labels
   "boundary",