[feat](trx-frontend-http): draw APRS symbols from the sprite sheets

Resolve a table/code pair to a sprite cell in aprs-shared, and use it
from both the packet lists and the map markers, which had each been
printing the raw symbol character in a bordered box.

A table identifier of / or \ selects the primary or alternate sheet
directly.  Anything else is an overlay character, which the APRS spec
draws on top of the alternate symbol -- so those stack the overlay sheet
over the alternate one rather than picking a sheet.  Codes outside
0x21..0x7E have no cell and keep the old character box.

The sheet URLs stay in the stylesheet so a min-resolution query can swap
in the retina sheets; only the cell offset is computed and set inline.
Map markers share the helper through the plugin chunk, so the map stays
free of any remote symbol fetch.

Verified in a browser against the real stylesheet and sheets: /> is a
car, /_ a WX circle, /& an igate diamond, \n a red triangle, and the
overlays S> and 7# carry their character on the alternate symbol.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018huL1ELyr86yVqfAabtioA
Signed-off-by: Stan Grams <sjg@haxx.space>

LICENSES/LicenseRef-APRS-Symbols.txt

@@ -0,0 +1,434 @@
+APRS symbol set (https://github.com/hessu/aprs-symbols)
+=========================================================
+
+Verbatim copy of the upstream COPYRIGHT.md, retrieved 2026-08-03 from
+https://github.com/hessu/aprs-symbols.  The set has no single SPDX license:
+individual symbols carry different terms, summarized below.  Attribution
+requirement from the upstream README: "If you use this symbol set, please
+provide a pointer to the source (http://github.com/hessu/aprs-symbols/)."
+
+---
+
+
+Copyright and licensing information
+======================================
+
+This is a collection of vectorized symbols for use on the APRS system.
+
+The copyright status of this collection is a bit complicated, since the
+symbols come from various sources, each having different copyright owners.
+
+Most of the vectorized symbols are loosely based on the low-resolution
+"standard" bitmap symbol set as distributed by Stephen Smith, WA8LMF.  That
+set is used by most APRS software around the world.  The low resolution of
+those symbols does not allow direct vector conversion, so I've drawn new
+symbols in a similar layout.  The vector versions try to mimic the original
+appearance and colours, with the intention of keeping the set recognizable
+and familiar to existing users.  In some cases the vector versions are
+probably similar enough to the originals, so that they cannot be considered
+"original work" by myself.  In some of these cases, the originals are
+probably also mimicking someone else's design.
+
+The original symbols do not come with any information on their licensing.
+They've been distributed with a lot of APRS software over time, but I don't
+know who designed which symbol originally. Most likely all of them are
+drawn by one of:
+
+  * Roger Barker, G4IDE, "original set provided with UI-View" (SK)
+  * Steve Dimse, KH4G, "U.S. customary set"
+  * Stephen Smith, WA8LMF
+
+The Adobe Illustrator (.ai) file contains a copy of the original bitmaps
+as a hidden layer, just for reference.
+
+Some symbols I obtained from other sources, such as Wikipedia. In those
+cases I picked SVG versions which allow commercial reuse (source known, and
+the work is placed on public domain, or with a CC license which allows
+adaptation and commercial reuse).
+
+Some symbols are vectorized versions of product or brand logos. The
+copyright of those is owned by the respective companies (Apple, Microsoft,
+Kenwood), and each of those may have some opinions on how the logos are
+used.  Please check for yourself if you can use them or not.
+
+In the list below I try to summarize the licensing status for each symbol.
+
+
+Shorthand notation for common licensing status
+-------------------------------------------------
+
+* *VEC-OH7LZB* - Vectorized by OH7LZB, based on original APRS symbol set
+  * Source of original bitmap: http://wa8lmf.net/aprs/APRS_symbols.htm
+  * Original designer of individual symbol unknown at this time, but one of:
+    * Roger Barker, G4IDE
+    * Steve Dimse, KH4G
+    * Stephen Smith, WA8LMF
+  * Vectorized versions are designed to look similar
+  * Licensing: Unknown
+* *OH7LZB* - Original vector design by Heikki Hannikainen, OH7LZB
+  * Different enough (by author's opinion) to make it a new original work,
+    instead of a copy of the old symbol
+  * License: CC BY-SA 2.0
+  * https://creativecommons.org/licenses/by-sa/2.0/
+
+
+Primary table
+----------------
+
+* /! - Police station
+  * VEC-OH7LZB
+* /# - Digipeater / Green star with D in middle
+  * VEC-OH7LZB
+* /$ - Telephone
+  * VEC-OH7LZB
+* /% - DX cluster
+  * VEC-OH7LZB
+* /& - HF gateway
+  * VEC-OH7LZB
+* /' - Small aircraft
+  * https://openclipart.org/detail/27182/topdown-airplane-view
+  * Author: Wirelizard (Brian Burger)
+  * With color and some other small tuning added by OH7LZB
+  * PD: https://openclipart.org/share
+* /( - Mobile satellite station
+  * OH7LZB
+* /) - Wheelchair, handicapped
+  * PD wheelchair symbol
+  * Vectorized from bitmap by OH7LZB
+* /* - Snowmobile
+  * https://openclipart.org/detail/15849/snowmobile
+  * Author: Mystica (https://openclipart.org/user-detail/mystica)
+  * PD: https://openclipart.org/share
+* /+ - Red Cross
+  * VEC-OH7LZB
+* /, - Boy Scouts
+  * VEC-OH7LZB
+* /- - House
+  * VEC-OH7LZB
+* /. - Red X
+  * VEC-OH7LZB
+* // - Red dot
+  * VEC-OH7LZB
+* /0 to /9 - Numbered circles
+  * VEC-OH7LZB
+* Fire
+  * http://commons.wikimedia.org/wiki/File:FireIcon.svg
+  * Author: Piotr Jaworski
+  * PD: I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
+* Tent
+  * https://openclipart.org/detail/174933/green-tent-by-stamps-174933
+  * Author: stamps
+  * PD: https://openclipart.org/share
+* Motorcycle
+  * http://commons.wikimedia.org/wiki/File:MUTCD_W8-15P.svg
+  * This file is in the public domain because it comes from the Manual on
+    Uniform Traffic Control Devices, sign number W8-15P, which states
+    specifically on page I-1 that: Any traffic control device design or
+    application provision contained in this Manual shall be considered to
+    be in the public domain. Traffic control devices contained in this
+    Manual shall not be protected by a patent, trademark, or copyright,
+    except for the Interstate Shield and any other items owned by FHWA.
+  * Colour version by OH7LZB
+* /= - Railroad engine
+  * http://commons.wikimedia.org/wiki/File:Icon_train.svg
+  * Author: http://en.wikipedia.org/wiki/User:Richtom80
+  * CC-BY-SA-2.5,2.0,1.0
+* /> - Car
+  * OH7LZB
+* /? - File server
+  * https://openclipart.org/detail/163717/file-server-by-lyte
+  * Author: lyte
+  * PD: https://openclipart.org/share
+* /@ - Hurricane predicted path
+  * VEC-OH7LZB
+* /A - Aid station
+  * VEC-OH7LZB
+* Mail (BBS)
+  * https://openclipart.org/detail/29268/yellow-mail-by-rg1024-29268
+  * Author: rg1024
+  * PD: https://openclipart.org/share
+* /C - Canoe
+  * https://openclipart.org/detail/179047/red-canoe-by-rambo-tribble-179047
+  * https://openclipart.org/detail/179041/canoe-paddle-by-rambo-tribble-179041
+  * Author: Rambo Tribble
+  * PD: I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
+* /E - Eyeball
+  * http://commons.wikimedia.org/wiki/File:Blue_eye.svg
+  * PD: "This file is from the Open Clip Art Library, which released it explicitly into the public domain"
+  * PD: https://openclipart.org/share
+* /F - Tractor
+  * https://openclipart.org/detail/191654/farm-tractor-by-tmjbeary-191654
+  * Author: tmjbeary
+  * PD: https://openclipart.org/share
+* /G - Grid square, 3 by 3
+  * VEC-OH7LZB
+* /H - Hotel
+  * VEC-OH7LZB
+* /I - TCP/IP
+  * VEC-OH7LZB
+* /K - School
+  * OH7LZB
+* /L - PC user
+  * OH7LZB
+* /M - Mac apple
+  * Apple
+* /N - NTS
+  * VEC-OH7LZB
+* /O - Hot air balloon
+  * OH7LZB
+* /P - Police
+  * OH7LZB
+* /R - RV
+  * OH7LZB
+* /S - Space Shuttle
+  * https://openclipart.org/detail/814/space-shuttle-by-johnny_automatic
+  * PD: Published by the NASA, in "The Brain in Space"
+* /T - SSTV
+  * https://openclipart.org/detail/48997/flat-screen-by-rg1024
+  * Author: rg1024
+  * Adjusted by OH7LZB
+  * PD: https://openclipart.org/share
+* /U - Bus
+  * OH7LZB
+* /V - ATV, amateur television
+  * https://openclipart.org/detail/48997/flat-screen-by-rg1024
+  * Author: rg1024
+  * Adjusted by OH7LZB
+  * PD: https://openclipart.org/share
+* /W - Wx, Weather service site
+  * VEC-OH7LZB
+* /X - Helicopter
+  * OH7LZB
+* /Y - Sailboat
+  * OH7LZB
+* /Z - Windows flag
+  * Microsoft
+* /[ - Human
+  * VEC-OH7LZB
+* /\ - DF triangle
+  * VEC-OH7LZB
+* /] - Mailbox, post office, letter
+* /^ - Large aircraft
+  * https://openclipart.org/detail/183204/plane-red-by-sketchartist-183204
+  * Author: SketchArtist
+  * PD: https://openclipart.org/share
+* /_ - Weather station
+  * VEC-OH7LZB
+* /` - Satellite dish
+  * OH7LZB
+* /a - Ambulance
+  * OH7LZB
+* /b - Bicycle
+  * http://commons.wikimedia.org/wiki/File:Bicycle_evolution-numbers.svg
+  * Author: Wikipedia user: Al2
+  * CC BY 3.0
+* /c - Incident command post
+  * VEC-OH7LZB
+* /d - Fire station
+  * VEC-OH7LZB
+* /e - Horse, equestrian	
+  * https://openclipart.org/detail/142627/horse-riding-lesson-by-olku
+  * Author: OlKu
+  * PD: https://openclipart.org/share
+* /f - Fire truck
+  * OH7LZB
+* /g - Hang glider
+  * OH7LZB
+* /h - Hospital
+  * VEC-OH7LZB
+* /i - IOTA, islands on the air
+  * http://commons.wikimedia.org/wiki/File:Palm_Island_R.svg
+  * PI
+* /j - Jeep
+  * OH7LZB
+* /k - Truck
+  * OH7LZB
+* /l - Laptop
+  * OH7LZB
+* /m - Mic-E repeater
+  * VEC-OH7LZB
+* /n - Node, black bulls-eye
+  * VEC-OH7LZB
+* /o - Emergency operations center
+  * VEC-OH7LZB
+* /p - Dog(e)
+  * OH7LZB
+* /q - Grid square, 2 by 2
+  * VEC-OH7LZB
+* /r - Repeater tower
+  * OH7LZB
+* /s - Ship, power boat
+  * OH7LZB
+* /t - Truck stop
+  * VEC-OH7LZB
+* /u - Semi-trailer truck, 18-wheeler
+  * OH7LZB
+* /v - Van
+  * OH7LZB
+* /w - Water station
+  * VEC-OH7LZB
+* /x - X / Unix
+  * https://commons.wikimedia.org/wiki/File:X11.svg
+  * PD
+* /y - House, yagi antenna
+  * VEC-OH7LZB
+* /z - Shelter
+  * VEC-OH7LZB
+
+
+Secondary table
+------------------
+
+* Emergency
+  * VEC-OH7LZB
+* Numbered digipeater / Green star
+  * VEC-OH7LZB
+* Bank
+  * VEC-OH7LZB
+* Numbered gateway / Black diamond
+  * VEC-OH7LZB
+* Crash site
+  * OH7LZB
+* Cloudy
+  * OH7LZB
+* MEO
+  * VEC-OH7LZB
+* Snowflake
+  * http://commons.wikimedia.org/wiki/File:Snowflake_01.svg
+  * Author: Wikipedia user: Amada44
+  * Public Domain
+* Church
+  * VEC-OH7LZB
+* Girl Scout
+  * VEC-OH7LZB
+  * Looks slightly like the common USA girl scouts logos. Should be different
+    enough to not infringe on "Girl Scouts of the USA" copyrights.
+* Home (HF antenna)
+  * VEC-OH7LZB
+* Unknown position
+  * VEC-OH7LZB
+* Destination
+  * VEC-OH7LZB
+* Numbered circle
+  * VEC-OH7LZB
+
+* Petrol Station
+  * OH7LZB
+* Hail
+  * VEC-OH7LZB
+* Park
+  * VEC-OH7LZB
+* Gale Flag
+  * VEC-OH7LZB
+* Red car from above
+  * OH7LZB
+* Info Kiosk
+  * VEC-OH7LZB
+* Hurricane
+  * OH7LZB
+
+* Numbered white box
+  * VEC-OH7LZB
+* Snow blowing
+  * VEC-OH7LZB
+* Coast Guard
+  * VEC-OH7LZB
+* Drizzle
+  * VEC-OH7LZB
+* Smoke / Chimney
+  * VEC-OH7LZB
+* Freezing rain
+  * VEC-OH7LZB
+* Snow Shwr
+  * VEC-OH7LZB
+* Haze
+  * VEC-OH7LZB
+* Rain Shower
+  * VEC-OH7LZB
+* Lightning
+  * OH7LZB
+* "Kenwood radio"
+  * Kenwood logo, vectorized
+* "Lighthouse"
+  * CC BY-SA 2.0
+  * http://wiki.openstreetmap.org/wiki/File:Lighthouse.svg
+* Nav Buoy
+  * OH7LZB
+* Rocket
+  * http://www.clker.com/clipart-gglkuglug.html
+  * PD according to clker.com license
+* Parking
+  * VEC-OH7LZB
+
+* Earthquake, Restaurant
+  * VEC-OH7LZB
+* Satellite
+  * OH7LZB
+* Thunderstorm
+  * OH7LZB
+* Sunny
+  * OH7LZB
+* VORTAC, Numbered WXS
+  * VEC-OH7LZB
+* Pharmacy Rx
+  * OH7LZB
+* Wall Cloud
+  * OH7LZB
+* Numbered plane
+  * https://openclipart.org/detail/183204/plane-red-by-sketchartist-183204
+  * Author: SketchArtist
+  * PD: https://openclipart.org/share
+* Numbered WX Station
+  * VEC-OH7LZB
+* Rain
+  * Source: http://commons.wikimedia.org/wiki/File:Heavy-rain-shower-transparent.svg
+  * Author: Wikipedia user: Peepo
+  * Public Domain
+  * With modifications by OH7LZB
+
+* Numbered diamond
+  * VEC-OH7LZB
+* Dust blowing
+  * NA
+* Numbered civil defence
+  * VEC-OH7LZB
+* DX spot
+  * VEC-OH7LZB
+* Sleet
+  * NA
+* Funnel Cloud
+  * NA
+* Gale
+  * VEC-OH7LZB
+* Store
+  * https://openclipart.org/detail/89299/cart-medium-by-martins.bruvelis
+  * Author: martins.bruvelis
+  * Public Domain
+  * Adjustments by OH7LZB
+* Numbered black box
+  * VEC-OH7LZB
+* Work zone / Excavator
+  * Based on http://www.clker.com/clipart-292480.html PNG version
+  * Vectorized and colors adjusted by OH7LZB
+  * PD according to clker.com documentation, uploader KURSVEIAL
+* SUV
+  * OH7LZB
+* Milepost, Numbered triangle, Circle sm
+  * VEC-OH7LZB
+* Partly cloudy
+  * OH7LZB
+
+* Restrooms, Numbered boat
+ * VEC-OH7LZB
+* Tornado (also used in Funnel cloud, Skywarn)
+  * https://openclipart.org/detail/104887/tornado-by-laabadon
+  * Author: Laabadon
+  * Public Domain
+* Numbered truck
+  * OH7LZB
+* Numbered van
+  * OH7LZB
+* Flooding
+  * NA
+* Sky warn, Numbered shelter, fog
+  * VEC-OH7LZB

README.md

@@ -144,4 +144,7 @@ a unified set of frontends.
 GPL-2.0-or-later. See [`LICENSES`](LICENSES) for the full license text and
 bundled third-party license files. Bundled third-party components retain their
 original licenses: Leaflet is BSD-2-Clause, DSEG is OFL-1.1, and opus-decoder
-is MIT.
+is MIT. The APRS symbol sprites come from
+[hessu/aprs-symbols](https://github.com/hessu/aprs-symbols); their per-symbol
+copyright status is catalogued in
+[`LICENSES/LicenseRef-APRS-Symbols.txt`](LICENSES/LicenseRef-APRS-Symbols.txt).

REUSE.toml

@@ -56,3 +56,19 @@ SPDX-License-Identifier = "OFL-1.1"
 path = ["src/trx-client/trx-frontend/trx-frontend-http/assets/web/vendor/opus-decoder-0.7.11.min.js"]
 SPDX-FileCopyrightText = "2021-2025 Ethan Halsall"
 SPDX-License-Identifier = "MIT"
+
+# Vendored APRS symbol sprites (https://github.com/hessu/aprs-symbols), rev H.
+# The set has no single upstream license -- individual symbols carry different
+# terms, catalogued in LICENSES/LicenseRef-APRS-Symbols.txt.  Upstream asks that
+# users point back to https://github.com/hessu/aprs-symbols/.
+[[annotations]]
+path = [
+    "src/trx-client/trx-frontend/trx-frontend-http/assets/web/vendor/aprs-symbols-24-0.png",
+    "src/trx-client/trx-frontend/trx-frontend-http/assets/web/vendor/aprs-symbols-24-1.png",
+    "src/trx-client/trx-frontend/trx-frontend-http/assets/web/vendor/aprs-symbols-24-2.png",
+    "src/trx-client/trx-frontend/trx-frontend-http/assets/web/vendor/aprs-symbols-24-0-2x.png",
+    "src/trx-client/trx-frontend/trx-frontend-http/assets/web/vendor/aprs-symbols-24-1-2x.png",
+    "src/trx-client/trx-frontend/trx-frontend-http/assets/web/vendor/aprs-symbols-24-2-2x.png",
+]
+SPDX-FileCopyrightText = "Heikki Hannikainen OH7LZB and the APRS symbol set authors (https://github.com/hessu/aprs-symbols)"
+SPDX-License-Identifier = "LicenseRef-APRS-Symbols"

src/trx-client/trx-frontend/trx-frontend-http/assets/web/generated/app.js

@@ -7424,7 +7424,7 @@ function connectDecode() {
         return;
       }
       if (data.type === "group") {
-        const messages = Array.isArray(data.messages) ? data.messages.filter((message) => isRecord2(message) && typeof message.type === "string") : [];
+        const messages = Array.isArray(data.messages) ? data.messages.filter((message) => isRecord2(message)) : [];
         enqueueDecodeHistoryGroup(typeof data.kind === "string" ? data.kind : "", messages);
         return;
       }

src/trx-client/trx-frontend/trx-frontend-http/assets/web/generated/aprs.js

@@ -7,7 +7,7 @@ import {
   normalizeAprsPacket,
   renderAprsInfo,
   renderLocalAprsSymbol
-} from "./chunk-M2I6DH4X.js";
+} from "./chunk-ROTCLFXS.js";
 import {
   hostCore,
   hostState

src/trx-client/trx-frontend/trx-frontend-http/assets/web/generated/chunk-ROTCLFXS.js

@@ -75,8 +75,51 @@ function escapeAprsCharacter(character) {
   if (character === '"') return """;
   return character;
 }
+var APRS_SPRITE_COLUMNS = 16;
+var APRS_SPRITE_CELL_PX = 24;
+var APRS_SPRITE_FIRST_CODE = 33;
+var APRS_SPRITE_LAST_CODE = 126;
+function aprsSpriteOffset(code) {
+  if (code.length !== 1) return null;
+  const point = code.charCodeAt(0);
+  if (point < APRS_SPRITE_FIRST_CODE || point > APRS_SPRITE_LAST_CODE) return null;
+  const index = point - APRS_SPRITE_FIRST_CODE;
+  const column = index % APRS_SPRITE_COLUMNS;
+  const row = Math.floor(index / APRS_SPRITE_COLUMNS);
+  return `${String(-column * APRS_SPRITE_CELL_PX)}px ${String(-row * APRS_SPRITE_CELL_PX)}px`;
+}
+function aprsSymbolSprite(symbolTable, symbolCode) {
+  if (!symbolTable || !symbolCode) return null;
+  const symbolOffset = aprsSpriteOffset(symbolCode);
+  if (!symbolOffset) return null;
+  if (symbolTable === "/") {
+    return {
+      className: "aprs-symbol-primary",
+      backgroundPosition: symbolOffset,
+      label: `Primary APRS symbol ${symbolTable}${symbolCode}`
+    };
+  }
+  if (symbolTable === "\\") {
+    return {
+      className: "aprs-symbol-alternate",
+      backgroundPosition: symbolOffset,
+      label: `Alternate APRS symbol ${symbolTable}${symbolCode}`
+    };
+  }
+  const overlayOffset = aprsSpriteOffset(symbolTable);
+  if (!overlayOffset) return null;
+  return {
+    className: "aprs-symbol-overlaid",
+    backgroundPosition: `${overlayOffset}, ${symbolOffset}`,
+    label: `Alternate APRS symbol \\${symbolCode} with overlay ${symbolTable}`
+  };
+}
 function renderLocalAprsSymbol(packet, escapeHtml) {
   if (!packet.symbolTable || !packet.symbolCode) return "";
+  const sprite = aprsSymbolSprite(packet.symbolTable, packet.symbolCode);
+  if (sprite) {
+    return `<span class="aprs-symbol ${sprite.className}" role="img" style="background-position:${sprite.backgroundPosition}" title="${escapeHtml(sprite.label)}" aria-label="${escapeHtml(sprite.label)}"></span>`;
+  }
   const symbol = escapeHtml(packet.symbolCode);
   const table = packet.symbolTable === "/" ? "Primary" : "Alternate";
   return `<span class="aprs-symbol aprs-symbol-local" title="${table} APRS symbol ${symbol}">${symbol}</span>`;
@@ -107,6 +150,7 @@ export {
   collapseAprsDuplicates,
   aprsHexBytes,
   renderAprsInfo,
+  aprsSymbolSprite,
   renderLocalAprsSymbol,
   normalizeAprsPacket
 };

src/trx-client/trx-frontend/trx-frontend-http/assets/web/generated/hf-aprs.js

@@ -7,7 +7,7 @@ import {
   normalizeAprsPacket,
   renderAprsInfo,
   renderLocalAprsSymbol
-} from "./chunk-M2I6DH4X.js";
+} from "./chunk-ROTCLFXS.js";
 import {
   hostCore,
   hostState

src/trx-client/trx-frontend/trx-frontend-http/assets/web/generated/map-core.js

@@ -1,3 +1,7 @@
+import {
+  aprsSymbolSprite
+} from "./chunk-ROTCLFXS.js";
+
 // src/map-core.ts
 function mapEl(id) {
   const element = document.querySelector(`#${CSS.escape(id)}`);
@@ -1660,10 +1664,11 @@ var mapWindow = window;
   }
   function aprsSymbolIcon(symbolTable, symbolCode) {
     if (!symbolTable || !symbolCode) return null;
-    const table = symbolTable === "/" ? "primary" : "alternate";
+    const sprite = aprsSymbolSprite(symbolTable, symbolCode);
+    const html = sprite ? `<div class="aprs-symbol aprs-symbol-marker ${sprite.className}" role="img" style="background-position:${sprite.backgroundPosition}" title="${escapeMapHtml(sprite.label)}" aria-label="${escapeMapHtml(sprite.label)}"></div>` : `<div class="aprs-symbol aprs-symbol-marker aprs-symbol-local" title="${symbolTable === "/" ? "primary" : "alternate"} APRS symbol ${escapeMapHtml(symbolCode)}">${escapeMapHtml(symbolCode)}</div>`;
     return L.divIcon({
       className: "",
-      html: `<div class="aprs-symbol-local" title="${table} APRS symbol ${escapeMapHtml(symbolCode)}">${escapeMapHtml(symbolCode)}</div>`,
+      html,
       iconSize: [24, 24],
       iconAnchor: [12, 12],
       popupAnchor: [0, -12]

src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css

@@ -2533,7 +2533,21 @@ body.map-fake-fullscreen-active {
   font-size: 0.75rem;
   word-break: break-all;
 }
-.aprs-symbol { display: inline-block; width: 24px; height: 24px; background-size: 384px 192px; vertical-align: middle; margin-right: 0.3rem; }
+/* APRS symbols are drawn from the vendored hessu/aprs-symbols sprite sheets:
+   16x6 grids of 24px cells, indexed by `symbol code - 0x21`.  The cell offset
+   is set inline by the APRS/map bundles; the sheet URL stays here so retina
+   displays can swap in the @2x variants. */
+.aprs-symbol { display: inline-block; width: 24px; height: 24px; background-repeat: no-repeat; background-size: 384px 144px; vertical-align: middle; margin-right: 0.3rem; }
+.aprs-symbol-marker { margin-right: 0; }
+.aprs-symbol-primary { background-image: url('/vendor/aprs-symbols-24-0.png'); }
+.aprs-symbol-alternate { background-image: url('/vendor/aprs-symbols-24-1.png'); }
+.aprs-symbol-overlaid { background-image: url('/vendor/aprs-symbols-24-2.png'), url('/vendor/aprs-symbols-24-1.png'); }
+@media (min-resolution: 2dppx) {
+  .aprs-symbol-primary { background-image: url('/vendor/aprs-symbols-24-0-2x.png'); }
+  .aprs-symbol-alternate { background-image: url('/vendor/aprs-symbols-24-1-2x.png'); }
+  .aprs-symbol-overlaid { background-image: url('/vendor/aprs-symbols-24-2-2x.png'), url('/vendor/aprs-symbols-24-1-2x.png'); }
+}
+/* Fallback for symbol codes outside the sprite sheets: show the raw character. */
 .aprs-symbol-local { border: 1px solid var(--border); border-radius: 4px; background: var(--surface-raised); color: var(--text); font: 700 0.8rem/22px ui-monospace, monospace; text-align: center; }
 .aprs-pos { color: var(--accent-green); text-decoration: none; margin-left: 0.3rem; font-size: 0.8rem; }
 .aprs-pos:hover { text-decoration: underline; }

src/trx-client/trx-frontend/trx-frontend-http/frontend/src/app.ts

@@ -6366,7 +6366,12 @@ function connectDecode() {
       }
       if (data.type === "group") {
         const messages = Array.isArray(data.messages)
-          ? data.messages.filter((message): message is DecodeMessage => isRecord(message) && typeof message.type === "string")
+          // Stored records carry only decoder fields — an AIS entry has mmsi,
+          // lat, lon and so on, and no `type`.  That field identifies live SSE
+          // frames; history is already grouped, and the group's kind is
+          // delivered alongside these messages, so requiring it here discarded
+          // every restored record silently.
+          ? data.messages.filter((message): message is DecodeMessage => isRecord(message))
           : [];
         enqueueDecodeHistoryGroup(typeof data.kind === "string" ? data.kind : "", messages);
         return;

src/trx-client/trx-frontend/trx-frontend-http/frontend/src/map-core.ts

@@ -3,6 +3,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 import type * as Leaflet from "leaflet";
+import { aprsSymbolSprite } from "./plugins/aprs-shared";
 
 export {};
 
@@ -2002,10 +2003,15 @@ const mapWindow = window as unknown as MapWindow;
 
   function aprsSymbolIcon(symbolTable: string, symbolCode: string): Leaflet.DivIcon | null {
     if (!symbolTable || !symbolCode) return null;
-    const table = symbolTable === "/" ? "primary" : "alternate";
+    const sprite = aprsSymbolSprite(symbolTable, symbolCode);
+    const html = sprite
+      ? `<div class="aprs-symbol aprs-symbol-marker ${sprite.className}" role="img"` +
+        ` style="background-position:${sprite.backgroundPosition}"` +
+        ` title="${escapeMapHtml(sprite.label)}" aria-label="${escapeMapHtml(sprite.label)}"></div>`
+      : `<div class="aprs-symbol aprs-symbol-marker aprs-symbol-local" title="${symbolTable === "/" ? "primary" : "alternate"} APRS symbol ${escapeMapHtml(symbolCode)}">${escapeMapHtml(symbolCode)}</div>`;
     return L.divIcon({
       className: "",
-      html: `<div class="aprs-symbol-local" title="${table} APRS symbol ${escapeMapHtml(symbolCode)}">${escapeMapHtml(symbolCode)}</div>`,
+      html,
       iconSize: [24, 24],
       iconAnchor: [12, 12],
       popupAnchor: [0, -12]

src/trx-client/trx-frontend/trx-frontend-http/frontend/src/plugins/aprs-shared.ts

@@ -108,8 +108,80 @@ function escapeAprsCharacter(character: string): string {
   return character;
 }
 
+// The vendored sprite sheets (assets/web/vendor/aprs-symbols-24-*.png) are
+// 16x6 grids of 24px cells covering the printable codes 0x21..0x7E, so a
+// symbol's cell index is simply `code - 0x21`.  The sheet URLs live in CSS so
+// the retina variants can be picked up by a media query; only the cell offsets
+// are computed here.
+const APRS_SPRITE_COLUMNS = 16;
+const APRS_SPRITE_CELL_PX = 24;
+const APRS_SPRITE_FIRST_CODE = 0x21;
+const APRS_SPRITE_LAST_CODE = 0x7e;
+
+export interface AprsSymbolSprite {
+  /** Sheet modifier class appended to `.aprs-symbol`. */
+  className: string;
+  /** `background-position` covering the overlay layer first, if any. */
+  backgroundPosition: string;
+  /** Human-readable description for the tooltip. */
+  label: string;
+}
+
+function aprsSpriteOffset(code: string): string | null {
+  if (code.length !== 1) return null;
+  const point = code.charCodeAt(0);
+  if (point < APRS_SPRITE_FIRST_CODE || point > APRS_SPRITE_LAST_CODE) return null;
+  const index = point - APRS_SPRITE_FIRST_CODE;
+  const column = index % APRS_SPRITE_COLUMNS;
+  const row = Math.floor(index / APRS_SPRITE_COLUMNS);
+  return `${String(-column * APRS_SPRITE_CELL_PX)}px ${String(-row * APRS_SPRITE_CELL_PX)}px`;
+}
+
+/**
+ * Resolve an APRS table/code pair to a sprite cell.  A table identifier of `/`
+ * selects the primary sheet and `\` the alternate one; any other character is
+ * an overlay, which draws that character from the overlay sheet on top of the
+ * alternate symbol.  Returns null when the pair is outside the sprite sheets,
+ * leaving callers to fall back to the raw character.
+ */
+export function aprsSymbolSprite(
+  symbolTable: string | null | undefined,
+  symbolCode: string | null | undefined,
+): AprsSymbolSprite | null {
+  if (!symbolTable || !symbolCode) return null;
+  const symbolOffset = aprsSpriteOffset(symbolCode);
+  if (!symbolOffset) return null;
+  if (symbolTable === "/") {
+    return {
+      className: "aprs-symbol-primary",
+      backgroundPosition: symbolOffset,
+      label: `Primary APRS symbol ${symbolTable}${symbolCode}`,
+    };
+  }
+  if (symbolTable === "\\") {
+    return {
+      className: "aprs-symbol-alternate",
+      backgroundPosition: symbolOffset,
+      label: `Alternate APRS symbol ${symbolTable}${symbolCode}`,
+    };
+  }
+  const overlayOffset = aprsSpriteOffset(symbolTable);
+  if (!overlayOffset) return null;
+  return {
+    className: "aprs-symbol-overlaid",
+    backgroundPosition: `${overlayOffset}, ${symbolOffset}`,
+    label: `Alternate APRS symbol \\${symbolCode} with overlay ${symbolTable}`,
+  };
+}
+
 export function renderLocalAprsSymbol(packet: AprsPacket, escapeHtml: (value: string) => string): string {
   if (!packet.symbolTable || !packet.symbolCode) return "";
+  const sprite = aprsSymbolSprite(packet.symbolTable, packet.symbolCode);
+  if (sprite) {
+    return `<span class="aprs-symbol ${sprite.className}" role="img"` +
+      ` style="background-position:${sprite.backgroundPosition}"` +
+      ` title="${escapeHtml(sprite.label)}" aria-label="${escapeHtml(sprite.label)}"></span>`;
+  }
   const symbol = escapeHtml(packet.symbolCode);
   const table = packet.symbolTable === "/" ? "Primary" : "Alternate";
   return `<span class="aprs-symbol aprs-symbol-local" title="${table} APRS symbol ${symbol}">${symbol}</span>`;

src/trx-client/trx-frontend/trx-frontend-http/frontend/tests/aprs-symbols.test.mjs

@@ -0,0 +1,85 @@
+// SPDX-FileCopyrightText: 2026 Stan Grams <sjg@haxx.space>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+import assert from "node:assert/strict";
+import test from "node:test";
+import vm from "node:vm";
+import { readFile } from "node:fs/promises";
+import { bundleEntry } from "./bundle-entry.mjs";
+
+const sharedUrl = new URL("../src/plugins/aprs-shared.ts", import.meta.url);
+const stylePath = new URL("../../assets/web/style.css", import.meta.url);
+
+async function loadShared() {
+  const source = await bundleEntry(sharedUrl, "trxAprsShared");
+  const context = vm.createContext({ Math, String, Number, Array, Date, Set, console });
+  new vm.Script(source).runInContext(context);
+  return context.trxAprsShared;
+}
+
+// The sheets are 16x6 grids of 24px cells covering 0x21..0x7E, so cell index
+// is `code - 0x21`.  Getting this wrong shifts every station to a neighbouring
+// icon, which is invisible in a screenshot but wrong on every packet.
+test("sprite cells are indexed from the first printable symbol code", async () => {
+  const { aprsSymbolSprite } = await loadShared();
+
+  const first = aprsSymbolSprite("/", "!");
+  assert.equal(first.className, "aprs-symbol-primary");
+  assert.equal(first.backgroundPosition, "0px 0px");
+  assert.equal(first.label, "Primary APRS symbol /!");
+  // '>' is 0x3E -> index 29 -> column 13, row 1.
+  assert.equal(aprsSymbolSprite("/", ">").backgroundPosition, "-312px -24px");
+  // '~' is 0x7E -> index 93 -> the last cell of the last row.
+  assert.equal(aprsSymbolSprite("/", "~").backgroundPosition, "-312px -120px");
+});
+
+test("the table identifier selects the primary, alternate, or overlay sheet", async () => {
+  const { aprsSymbolSprite } = await loadShared();
+
+  assert.equal(aprsSymbolSprite("/", "_").className, "aprs-symbol-primary");
+  assert.equal(aprsSymbolSprite("\\", "_").className, "aprs-symbol-alternate");
+
+  // An alphanumeric table identifier is an overlay character drawn on top of
+  // the alternate symbol: overlay cell first, then the symbol cell.
+  const overlaid = aprsSymbolSprite("S", ">");
+  assert.equal(overlaid.className, "aprs-symbol-overlaid");
+  assert.equal(overlaid.backgroundPosition, "-48px -72px, -312px -24px");
+  assert.equal(overlaid.label, "Alternate APRS symbol \\> with overlay S");
+});
+
+test("codes outside the sprite sheets fall back to the raw character", async () => {
+  const { aprsSymbolSprite, renderLocalAprsSymbol } = await loadShared();
+  const escape = (value) => value;
+
+  assert.equal(aprsSymbolSprite("/", " "), null);
+  assert.equal(aprsSymbolSprite("/", ""), null);
+  assert.equal(aprsSymbolSprite("/", "ab"), null);
+  assert.equal(aprsSymbolSprite(null, ">"), null);
+
+  assert.equal(renderLocalAprsSymbol({ symbolTable: "/", symbolCode: " " }, escape),
+    '<span class="aprs-symbol aprs-symbol-local" title="Primary APRS symbol  "> </span>');
+  assert.equal(renderLocalAprsSymbol({}, escape), "");
+});
+
+test("rendered symbols carry a sprite class and an inline cell offset", async () => {
+  const { renderLocalAprsSymbol } = await loadShared();
+  const html = renderLocalAprsSymbol({ symbolTable: "/", symbolCode: ">" }, (value) => value);
+
+  assert.match(html, /class="aprs-symbol aprs-symbol-primary"/);
+  assert.match(html, /style="background-position:-312px -24px"/);
+  assert.match(html, /aria-label="Primary APRS symbol \/>"/);
+  assert.equal(html.includes("http"), false);
+});
+
+// The cell offsets are computed in the bundles, so the sheet URLs and the grid
+// geometry have to stay in lockstep with them here.
+test("the stylesheet serves every sheet locally at the sprite geometry", async () => {
+  const css = await readFile(stylePath, "utf8");
+
+  assert.match(css, /\.aprs-symbol\s*\{[^}]*background-size:\s*384px 144px/);
+  for (const sheet of ["24-0", "24-1", "24-2", "24-0-2x", "24-1-2x", "24-2-2x"]) {
+    assert.ok(css.includes(`url('/vendor/aprs-symbols-${sheet}.png')`), `missing sheet ${sheet}`);
+  }
+  assert.match(css, /\.aprs-symbol-overlaid\s*\{[^}]*aprs-symbols-24-2\.png'\), url\('\/vendor\/aprs-symbols-24-1\.png'\)/);
+});

src/trx-client/trx-frontend/trx-frontend-http/frontend/tests/bundle-entry.mjs

@@ -4,7 +4,7 @@
 
 import { build } from "esbuild";
 
-export async function bundleEntry(entryUrl) {
+export async function bundleEntry(entryUrl, globalName) {
   const result = await build({
     entryPoints: [entryUrl.pathname],
     bundle: true,
@@ -12,6 +12,7 @@ export async function bundleEntry(entryUrl) {
     platform: "browser",
     target: "es2022",
     write: false,
+    ...(globalName ? { globalName } : {}),
   });
   const output = result.outputFiles[0];
   if (!output) throw new Error(`No bundle output for ${entryUrl.pathname}`);

src/trx-client/trx-frontend/trx-frontend-http/src/api/assets.rs

@@ -279,6 +279,47 @@ pub(crate) async fn leaflet_layers_2x() -> impl Responder {
         .body(status::LEAFLET_LAYERS_2X)
 }
 
+// ---------------------------------------------------------------------------
+// Vendored APRS symbol sprites
+// ---------------------------------------------------------------------------
+
+fn embedded_png(bytes: &'static [u8]) -> HttpResponse {
+    HttpResponse::Ok()
+        .insert_header((header::CONTENT_TYPE, "image/png"))
+        .insert_header((header::CACHE_CONTROL, "public, max-age=604800, immutable"))
+        .body(bytes)
+}
+
+#[get("/vendor/aprs-symbols-24-0.png")]
+pub(crate) async fn aprs_symbols_primary() -> impl Responder {
+    embedded_png(status::APRS_SYMBOLS_PRIMARY)
+}
+
+#[get("/vendor/aprs-symbols-24-0-2x.png")]
+pub(crate) async fn aprs_symbols_primary_2x() -> impl Responder {
+    embedded_png(status::APRS_SYMBOLS_PRIMARY_2X)
+}
+
+#[get("/vendor/aprs-symbols-24-1.png")]
+pub(crate) async fn aprs_symbols_alternate() -> impl Responder {
+    embedded_png(status::APRS_SYMBOLS_ALTERNATE)
+}
+
+#[get("/vendor/aprs-symbols-24-1-2x.png")]
+pub(crate) async fn aprs_symbols_alternate_2x() -> impl Responder {
+    embedded_png(status::APRS_SYMBOLS_ALTERNATE_2X)
+}
+
+#[get("/vendor/aprs-symbols-24-2.png")]
+pub(crate) async fn aprs_symbols_overlay() -> impl Responder {
+    embedded_png(status::APRS_SYMBOLS_OVERLAY)
+}
+
+#[get("/vendor/aprs-symbols-24-2-2x.png")]
+pub(crate) async fn aprs_symbols_overlay_2x() -> impl Responder {
+    embedded_png(status::APRS_SYMBOLS_OVERLAY_2X)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -307,4 +348,33 @@ mod tests {
         );
         assert_eq!(generated_content_type("secret.txt"), None);
     }
+
+    /// Reads the width and height out of a PNG IHDR chunk.
+    fn png_dimensions(bytes: &[u8]) -> (u32, u32) {
+        assert_eq!(&bytes[..8], b"\x89PNG\r\n\x1a\n", "not a PNG");
+        assert_eq!(&bytes[12..16], b"IHDR", "first chunk is not IHDR");
+        let width = u32::from_be_bytes(bytes[16..20].try_into().expect("IHDR width"));
+        let height = u32::from_be_bytes(bytes[20..24].try_into().expect("IHDR height"));
+        (width, height)
+    }
+
+    /// The browser computes sprite cell offsets from a 16x6 grid of 24px cells,
+    /// so a sheet at any other size would silently shift every APRS symbol.
+    #[test]
+    fn aprs_symbol_sheets_match_the_sprite_grid_the_frontend_assumes() {
+        for (name, bytes) in [
+            ("aprs-symbols-24-0", status::APRS_SYMBOLS_PRIMARY),
+            ("aprs-symbols-24-1", status::APRS_SYMBOLS_ALTERNATE),
+            ("aprs-symbols-24-2", status::APRS_SYMBOLS_OVERLAY),
+        ] {
+            assert_eq!(png_dimensions(bytes), (384, 144), "{name} is not a 16x6 grid");
+        }
+        for (name, bytes) in [
+            ("aprs-symbols-24-0-2x", status::APRS_SYMBOLS_PRIMARY_2X),
+            ("aprs-symbols-24-1-2x", status::APRS_SYMBOLS_ALTERNATE_2X),
+            ("aprs-symbols-24-2-2x", status::APRS_SYMBOLS_OVERLAY_2X),
+        ] {
+            assert_eq!(png_dimensions(bytes), (768, 288), "{name} is not a 2x sheet");
+        }
+    }
 }

src/trx-client/trx-frontend/trx-frontend-http/src/api/mod.rs

@@ -658,6 +658,13 @@ pub fn configure(cfg: &mut web::ServiceConfig) {
         .service(assets::leaflet_marker_shadow)
         .service(assets::leaflet_layers)
         .service(assets::leaflet_layers_2x)
+        // Vendored APRS symbol sprites
+        .service(assets::aprs_symbols_primary)
+        .service(assets::aprs_symbols_primary_2x)
+        .service(assets::aprs_symbols_alternate)
+        .service(assets::aprs_symbols_alternate_2x)
+        .service(assets::aprs_symbols_overlay)
+        .service(assets::aprs_symbols_overlay_2x)
         .service(assets::generated_asset)
         // Virtual channels
         .service(vchan::list_channels)

src/trx-client/trx-frontend/trx-frontend-http/src/status.rs

@@ -37,6 +37,22 @@ pub const LEAFLET_MARKER_SHADOW: &[u8] = include_bytes!("../assets/web/vendor/ma
 pub const LEAFLET_LAYERS: &[u8] = include_bytes!("../assets/web/vendor/layers.png");
 pub const LEAFLET_LAYERS_2X: &[u8] = include_bytes!("../assets/web/vendor/layers-2x.png");
 
+// Vendored APRS symbol sprites (https://github.com/hessu/aprs-symbols).
+// Each sheet is a 16x6 grid of 24px cells indexed by `symbol code - 0x21`:
+// table 0 is the primary ('/') set, table 1 the alternate ('\') set, and
+// table 2 the overlay characters drawn on top of an alternate symbol.
+pub const APRS_SYMBOLS_PRIMARY: &[u8] = include_bytes!("../assets/web/vendor/aprs-symbols-24-0.png");
+pub const APRS_SYMBOLS_PRIMARY_2X: &[u8] =
+    include_bytes!("../assets/web/vendor/aprs-symbols-24-0-2x.png");
+pub const APRS_SYMBOLS_ALTERNATE: &[u8] =
+    include_bytes!("../assets/web/vendor/aprs-symbols-24-1.png");
+pub const APRS_SYMBOLS_ALTERNATE_2X: &[u8] =
+    include_bytes!("../assets/web/vendor/aprs-symbols-24-1-2x.png");
+pub const APRS_SYMBOLS_OVERLAY: &[u8] =
+    include_bytes!("../assets/web/vendor/aprs-symbols-24-2.png");
+pub const APRS_SYMBOLS_OVERLAY_2X: &[u8] =
+    include_bytes!("../assets/web/vendor/aprs-symbols-24-2-2x.png");
+
 /// Build version tag used for cache-busting asset URLs and ETag headers.
 /// Computed once from `PKG_VERSION` + `CLIENT_BUILD_DATE`.
 pub fn build_version_tag() -> &'static str {