Drop the OsmAnd-recolor map theme, add offline labels and a lighter palette nudge

Remove osmand-style.js (the per-layer color-patching approach) and its
docs entirely — back to the plain OpenFreeMap "liberty" style online,
and protomaps-themes-base's stock theme offline as the base.

Offline maps previously had no text labels at all: the
protomaps-themes-base layers() call never passed a lang option, which
is required to include its label layers. Fixed, backed by vendored
Noto Sans Regular/Italic/Medium glyph PBFs (ranges 0-255 and 256-511
only — Basic Latin + Latin-1 Supplement + Latin Extended-A, enough for
accented Central European place names; other scripts won't render
offline). Verified against the actual offline.pmtiles vector layer
schema that the name/name:en/script fields this expects are present.

Also nudge a handful of OFFLINE_THEME color roles (background, water,
wood, buildings, the two road-importance tiers) towards the online
style's actual palette (sampled from its style JSON) so switching
Online/Offline doesn't look like two different apps — deliberately
partial, not the removed full recolor.

README.adoc

@@ -10,8 +10,7 @@ The project's shape is still open — this is the initial scaffold.
 == Status
 
 Early scaffold. The web application serves a vector map (MapLibre GL
-JS), styled to resemble https://osmand.net/map[OsmAnd's own map], with
+JS), with an online style and an optional offline style backed by a local
-an online style and an optional offline style backed by a local
 PMTiles file, an animated RainViewer radar overlay, GPX
 upload/display (points and tracks, organized in folders), and a live
 position marker from a local GNSS receiver via gpsd.

docs/architecture.adoc

@@ -70,59 +70,39 @@ support) just returns byte ranges of the file; pmtiles.js in the
 browser reads the archive's own directory and requests only the bytes
 it needs for the tiles on screen.
 
-=== Known limitation: no offline text labels
+=== Offline text labels and color palette
 
-The offline style only renders `protomaps-themes-base`'s non-label
+Label rendering in MapLibre needs a "glyphs" server serving font PBF
-layers (roads, buildings, land use, water — no place names or street
+ranges (256 Unicode code points each); `data/offline.pmtiles`'s fields
-labels). Label rendering in MapLibre needs a "glyphs" server serving
+(`name`, `name:en`, `script`, ...) match what
-font PBF ranges, which would mean vendoring a font glyph set locally
+`protomaps-themes-base`'s `layers(source, theme, { lang: "en" })`
-too; that has not been done, to keep the initial scope manageable.
+expects for its label layers (verified against the actual PMTiles
-Revisit this if labelled offline maps turn out to matter in practice.
+vector layer schema), so passing that option turns labels on. The
+glyphs themselves are vendored under `public/vendor/fonts/` — Noto
+Sans Regular/Italic/Medium, ranges `0-255` and `256-511`
+(Basic Latin + Latin-1 Supplement + Latin Extended-A, SIL OFL
+licensed, from
+https://github.com/protomaps/basemaps-assets[protomaps/basemaps-assets]),
+covering accented Latin place names (Slovak, Czech, Polish, German,
+...). Labels in other scripts (Cyrillic, Greek, CJK, ...) won't render
+offline, since those glyph ranges aren't vendored.
+
+`public/js/map.js`'s `OFFLINE_THEME` also nudges a handful of color
+roles (background, water, wood, buildings, the two road-importance
+tiers) from `protomaps-themes-base`'s stock "light" theme towards the
+online "liberty" style's actual palette (sampled from its style JSON),
+so Online/Offline don't look like two different apps. This is
+deliberately partial — most roles (labels, casings, minor terrain
+fills, ...) are left at their theme defaults — not the kind of
+full per-layer recolor a previous iteration of this app did (and
+removed, along with any dependency on OsmAnd's own tile server, which
+this app cannot use per OsmAnd's terms restricting tile use to "personal,
+non-commercial use within OsmAnd applications and platforms").
 
 No PMTiles file ships with the repository — it is expected to be
 supplied locally (see `docs/development.adoc`) and stays gitignored
 because such extracts are typically large binary files.
 
-=== Visual style
-
-Both styles are recolored, by `public/js/osmand-style.js`, to
-approximate the look of https://osmand.net/map[OsmAnd's own web map]
-(cream background, green forests, orange roads, purple admin
-boundaries) — deliberately *not* by using OsmAnd's tile server
-directly: its terms restrict tile use to "personal, non-commercial use
-within OsmAnd applications and platforms", which this app isn't.
-
-One shared color palette drives two independent recolorings:
-
-* *Online*: `onlineStyle()` fetches OpenFreeMap's raw "liberty" style
-  JSON and patches `paint` colors on its layers in place — matching a
-  layer to a category (water, wood, park, landuse, building, major/
-  minor road, boundary) by its id, then walking that layer's color
-  properties (`background-color`, `fill-color`, `line-color`,
-  `fill-extrusion-color`, and any `*-outline-color`) and replacing
-  every color-shaped leaf — including inside `interpolate`/other
-  expressions — with the category's palette color, leaving non-color
-  leaves (operators, zoom stops, `["get", ...]`) untouched. Labels and
-  railways are left at their original colors — only categorized layer
-  types (`background`/`fill`/`line`/`fill-extrusion`) are touched at
-  all, so `symbol` layers (all labels/icons) are never in scope.
-  Result is cached after the first fetch.
-* *Offline*: `offlineTheme()` overrides the relevant color roles on a
-  `protomaps-themes-base` `Theme` object (starting from
-  `namedTheme("light")`), leaving roles it doesn't set (labels — moot,
-  see above — rail, tunnels, POI colors) at their defaults.
-
-=== Known limitation: coarser road colors offline
-
-protomaps-themes-base's `Theme` only has two paint-relevant road tiers
-(`major` / `minor_a`+`minor_b`, plus `link` for ramps) versus
-OpenFreeMap's finer-grained classes (`road_motorway`,
-`road_trunk_primary`, `road_secondary_tertiary`, `road_minor`, ...).
-Mapping `major` to the palette's road-major orange colors more roads
-orange offline than online (protomaps' "major" bucket is broader than
-just motorway/trunk/primary) — a real difference in how coarse the two
-underlying style systems are, not a bug in the recoloring itself.
-
 == Weather radar overlay
 
 `public/js/radar.js` adds a "Radar" map control that overlays recent

docs/third-party-notices.adoc

@@ -23,6 +23,20 @@ BSD-3-Clause licensed.
 | https://github.com/protomaps/basemaps
 |===
 
+Offline map text labels need font glyphs too (see
+`docs/architecture.adoc`), vendored under `public/vendor/fonts/` —
+SIL Open Font License, not BSD-3-Clause like the above:
+
+[cols="1,2"]
+|===
+| Asset | Source
+
+| Noto Sans Regular/Italic/Medium glyph PBFs (ranges `0-255`,
+`256-511` only)
+| https://github.com/protomaps/basemaps-assets[protomaps/basemaps-assets]
+(`fonts/`, `OFL.txt` included alongside)
+|===
+
 The online map style (not vendored, fetched at runtime when the
 "Online" layer is selected) is
 https://tiles.openfreemap.org/styles/liberty[OpenFreeMap "liberty"],

public/js/map.js

@@ -7,24 +7,41 @@ import {
 import { RadarControl } from "/js/radar.js";
 import { GpxPanelControl } from "/js/gpx.js";
 import { GnssControl } from "/js/gnss.js";
-import { onlineStyle, offlineTheme } from "/js/osmand-style.js";
 import { LAYERS_ICON } from "/js/icons.js";
 import { notifySidePanelOpen, onlyOneSidePanelOpen } from "/js/panels.js";
 
 const CENTER = [17.1077, 48.1486];
 const ZOOM = 13;
+const ONLINE_STYLE = "https://tiles.openfreemap.org/styles/liberty";
 
 const protocol = new pmtiles.Protocol();
 addProtocol("pmtiles", protocol.tile);
 
-// No label layers here (see docs/architecture.adoc): rendering text needs a
+// A few color roles nudged from protomaps-themes-base's stock "light" theme
-// glyphs server, which the offline style deliberately does not depend on.
+// towards the online OpenFreeMap "liberty" style's actual palette (sampled
+// from its style JSON — see docs/architecture.adoc), so switching between
+// Online/Offline doesn't look like two different apps. Not a full recolor:
+// most roles (labels, casings, minor terrain fills, ...) are left at their
+// theme defaults.
+const OFFLINE_THEME = {
+  ...protomaps_themes_base.namedTheme("light"),
+  background: "#f8f4f0",
+  earth: "#f8f4f0",
+  water: "#9ebdff",
+  wood_a: "#ace38c",
+  wood_b: "#ace38c",
+  buildings: "#dcd9d6",
+  highway: "#f2934a",
+  major: "#ffeeaa",
+  link: "#ffeeaa",
+};
+
 function offlineStyle() {
-  const theme = offlineTheme(protomaps_themes_base.namedTheme("light"));
   const pmtilesUrl = `${window.location.origin}/tiles/offline.pmtiles`;
 
   return {
     version: 8,
+    glyphs: `${window.location.origin}/vendor/fonts/{fontstack}/{range}.pbf`,
     sources: {
       offline: {
         type: "vector",
@@ -32,7 +49,10 @@ function offlineStyle() {
         attribution: "© OpenStreetMap contributors",
       },
     },
-    layers: protomaps_themes_base.layers("offline", theme),
+    // lang: "en" pulls in labels_layers (see docs/architecture.adoc) — only
+    // the Latin-script glyph ranges are vendored, so labels using other
+    // scripts won't render offline.
+    layers: protomaps_themes_base.layers("offline", OFFLINE_THEME, { lang: "en" }),
   };
 }
 
@@ -83,7 +103,7 @@ class LayerToggleControl {
 
 const map = new MaplibreMap({
   container: "map",
-  style: await onlineStyle(),
+  style: ONLINE_STYLE,
   center: CENTER,
   zoom: ZOOM,
 });
@@ -108,9 +128,9 @@ new GpxPanelControl(map).mount(sidebar);
 new RadarControl(map).mount(sidebar);
 new GnssControl(map).mount(sidebar);
 
-async function applyStyle(name) {
+function applyStyle(name) {
   layerToggle.setActive(name);
-  map.setStyle(name === "offline" ? offlineStyle() : await onlineStyle());
+  map.setStyle(name === "offline" ? offlineStyle() : ONLINE_STYLE);
 }
 
 // If a local PMTiles file is present, prefer it as the default style — its

public/js/osmand-style.js

@@ -1,160 +0,0 @@
-// Approximates the look of OsmAnd's own map render (osmand.net/map — muted
-// earth tones, cream background, orange roads) without depending on their
-// tile server: OsmAnd's terms restrict tile use to "personal, non-commercial
-// use within OsmAnd applications and platforms", which this app isn't.
-//
-// One shared palette drives two independent recolorings so Online and
-// Offline look consistent: OpenFreeMap's "liberty" vector style (paint
-// colors patched in place, see recolorLayer) for Online, and a custom
-// protomaps-themes-base Theme (see offlineTheme) for Offline.
-
-const PALETTE = {
-  background: "#f1ecd7",
-  water: "#aad3df",
-  wood: "#c8dfb0",
-  park: "#d3e8b8",
-  landuse: "#ece4c6",
-  building: "#d9cead",
-  buildingOutline: "#c7bb92",
-  roadMajor: "#eb9d43",
-  roadMajorCasing: "#c9822c",
-  roadMinor: "#fdf8ee",
-  roadMinorCasing: "#cfc09a",
-  boundary: "#a98fc2",
-};
-
-const LIBERTY_STYLE_URL = "https://tiles.openfreemap.org/styles/liberty";
-let cachedOnlineStyle = null;
-
-// Fetches OpenFreeMap's "liberty" style and recolors it in place. Cached —
-// the recoloring is pure, and re-fetching on every Online/Offline toggle
-// would be wasteful.
-export async function onlineStyle() {
-  if (cachedOnlineStyle) return cachedOnlineStyle;
-
-  const response = await fetch(LIBERTY_STYLE_URL);
-  const style = await response.json();
-  style.layers = style.layers.map(recolorLayer);
-  cachedOnlineStyle = style;
-  return style;
-}
-
-// Overrides the color roles that define the "look" on top of a
-// protomaps-themes-base Theme (e.g. namedTheme("light")), leaving roles it
-// doesn't set (labels, rail, tunnels, POI colors) at their defaults.
-export function offlineTheme(baseTheme) {
-  return {
-    ...baseTheme,
-    background: PALETTE.background,
-    earth: PALETTE.background,
-    water: PALETTE.water,
-    wood_a: PALETTE.wood,
-    wood_b: PALETTE.wood,
-    park_a: PALETTE.park,
-    park_b: PALETTE.park,
-    scrub_a: PALETTE.park,
-    scrub_b: PALETTE.park,
-    pedestrian: PALETTE.landuse,
-    industrial: PALETTE.landuse,
-    school: PALETTE.landuse,
-    hospital: PALETTE.landuse,
-    buildings: PALETTE.building,
-    highway_casing_early: PALETTE.roadMajorCasing,
-    highway_casing_late: PALETTE.roadMajorCasing,
-    highway: PALETTE.roadMajor,
-    major_casing_early: PALETTE.roadMajorCasing,
-    major_casing_late: PALETTE.roadMajorCasing,
-    major: PALETTE.roadMajor,
-    link_casing: PALETTE.roadMajorCasing,
-    link: PALETTE.roadMajor,
-    minor_casing: PALETTE.roadMinorCasing,
-    minor_service_casing: PALETTE.roadMinorCasing,
-    minor_a: PALETTE.roadMinor,
-    minor_b: PALETTE.roadMinor,
-    other: PALETTE.roadMinor,
-    minor_service: PALETTE.roadMinor,
-    boundaries: PALETTE.boundary,
-  };
-}
-
-const FILL_PROP = /^(background-color|fill-color|line-color|fill-extrusion-color)$/;
-const OUTLINE_PROP = /outline-color$/;
-
-const FILL_COLOR = {
-  background: PALETTE.background,
-  water: PALETTE.water,
-  wood: PALETTE.wood,
-  park: PALETTE.park,
-  landuse: PALETTE.landuse,
-  building: PALETTE.building,
-  roadMajor: PALETTE.roadMajor,
-  roadMinor: PALETTE.roadMinor,
-  boundary: PALETTE.boundary,
-};
-
-const OUTLINE_COLOR = {
-  building: PALETTE.buildingOutline,
-  roadMajor: PALETTE.roadMajorCasing,
-  roadMinor: PALETTE.roadMinorCasing,
-  park: "#bcdb9a",
-};
-
-// Maps a "liberty" style layer id to one of the categories above, based on
-// the id naming conventions OpenFreeMap's style uses (verified against its
-// actual layer list — see docs/architecture.adoc). Returns null for
-// anything left at its original color: labels/icons (all "symbol" layers,
-// filtered by type below before this even runs), railways, and minor
-// terrain fills (ice/wetland/sand) that aren't part of OsmAnd's signature
-// look.
-function categoryFor(layerId) {
-  if (layerId === "background") return "background";
-  if (/rail/.test(layerId)) return null;
-  if (/^water/.test(layerId)) return "water";
-  if (/^landcover_wood/.test(layerId)) return "wood";
-  if (/^(park|landcover_grass)/.test(layerId)) return "park";
-  if (/^landuse/.test(layerId)) return "landuse";
-  if (/^building/.test(layerId)) return "building";
-  if (/^(road|bridge|tunnel)_(motorway|trunk_primary)/.test(layerId)) return "roadMajor";
-  if (/^(road|bridge|tunnel)_/.test(layerId)) return "roadMinor";
-  if (/^boundary/.test(layerId)) return "boundary";
-  return null;
-}
-
-const RECOLORABLE_TYPES = new Set(["background", "fill", "line", "fill-extrusion"]);
-
-function recolorLayer(layer) {
-  if (!RECOLORABLE_TYPES.has(layer.type) || !layer.paint) return layer;
-
-  const category = categoryFor(layer.id);
-  if (!category) return layer;
-
-  const paint = { ...layer.paint };
-  for (const [prop, value] of Object.entries(paint)) {
-    if (OUTLINE_PROP.test(prop) && OUTLINE_COLOR[category]) {
-      paint[prop] = replaceColors(value, OUTLINE_COLOR[category]);
-    } else if (FILL_PROP.test(prop)) {
-      paint[prop] = replaceColors(value, FILL_COLOR[category]);
-    }
-  }
-
-  return { ...layer, paint };
-}
-
-const COLOR_PATTERN = /^#[0-9a-f]{3,8}$/i;
-const COLOR_FN_PATTERN = /^(rgb|hsl)a?\(/i;
-
-// Walks a paint value — a flat color string, or a MapLibre expression like
-// ["interpolate", ["linear"], ["zoom"], 5, "hsl(26,87%,62%)", 6, "#fc8"] —
-// and swaps every color-shaped string for `newColor`, leaving operators,
-// zoom/get references and numbers untouched. Generic across expression
-// types (interpolate/match/case/step/...) since it never inspects the
-// expression's operator, only whether each leaf looks like a color.
-function replaceColors(value, newColor) {
-  if (typeof value === "string") {
-    return COLOR_PATTERN.test(value) || COLOR_FN_PATTERN.test(value) ? newColor : value;
-  }
-  if (Array.isArray(value)) {
-    return value.map((item) => replaceColors(item, newColor));
-  }
-  return value;
-}

public/vendor/fonts/OFL.txt

@@ -0,0 +1,93 @@
+Copyright 2022 The Noto Project Authors (https://github.com/notofonts)
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+https://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
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+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
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+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
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+TERMINATION
+This license becomes null and void if any of the above conditions are
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+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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