* perf(timing): say which render-thread work a late frame followed The soak already says how often a moving frame reached the panel late, but not what the render thread was doing just before it. Vegas does two kinds of work there between frames -- building its strip (compose, extend) and, with live elements, patching changed pixels into it -- and deciding whether either is affordable needs their own numbers. - FrameTimingRecorder.note_op(kind, nbytes) tags the next presented frame. Totals gain op_frames, late_op_frames, op_freezes and op_bytes per kind; aggregate() still takes frames without ops. The file schema is unchanged. - Vegas tags compose and every strip extension (with the bytes it copied). - frame_soak prints an "after work" table: frames, late %, freezes and MB moved per kind, only when something tagged its work. - render_bench gains --strip-screens (Vegas-sized strips), --patch-bytes / --patch-every / --patch-where (in-place column writes, as a live element update does) and --extend-every-screens / --extend-width (append + trim on a fixed cadence that holds the strip's width). No runtime behaviour changes: this is the measurement gate for live Vegas elements. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * docs(changelog): note the frame-op attribution and bench modes Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * perf(scroll): build the strip's PIL image only when something reads it Every Vegas strip extension rebuilt ScrollHelper.cached_image from cached_array in full, twice (append, then trim), on the render thread: Image.fromarray is 1.7ms for an 8,000px strip and 3.8ms for 20,000px on a Pi 4 (measured on ledpi), about two thirds of an extension's render-thread cost. Nothing on the frame path reads the image's pixels; every frame is cut from the array. cached_image is now a property. append_content and drop_scrolled_prefix defer it; the first read builds it from the array it started with and keeps it only if the strip has not changed meanwhile, so a sync push racing an extension cannot leave a stale image cached. Assigning cached_image stores exactly what was assigned, as before. has_strip() says whether there is a strip without building its image; the helper's frame path, Vegas and the adapter's scroll-cache invalidation use it. The strip is also no longer held in memory twice. In Vegas the image is now built only by a multi-display sync push. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * feat(vegas): live elements -- a plugin API for content that changes while it scrolls Vegas bakes each plugin's pictures into one strip, so a card already on its way across the panel keeps what it showed when it was drawn. This adds the API and bookkeeping for content that can be updated in place; the worker that redraws and swaps it follows separately. No shipped plugin implements the hook yet, so nothing changes for users. Plugin API (core 3.8.0), all no-ops by default: - BasePlugin.get_vegas_elements() -> [VegasElement(key, image, version, live, refresh_hz)]: named, fixed-width pieces of Vegas content. - BasePlugin.redraw_vegas_element(key, width, height, at): a lock-free redraw for content that changes with time. - BasePlugin.notify_vegas_data_changed(): data that lands outside update(). - src/plugin_system/vegas_elements.py (VegasElement, re-exported from base_plugin). Core: - PluginAdapter asks a plugin that implements the hook for elements on the background fetch only (under its lock, on its own canvas); every other path keeps get_vegas_content(). Live elements are pinned (padded with content_padding, never trimmed), tagged with their key, digest and data epoch in Image.info so the existing cache and group plumbing carry them unchanged, and untagged if a width budget crops them. - RenderPipeline records where each live element lands (ElementRecord), in absolute strip columns a trim does not move; the block-start arithmetic is shared with the STATIC markers. - PluginManager update listeners (add/remove_update_listener, notify_data_changed): told the moment update() completes, not at the next ~4s Vegas poll. The coordinator uses one to move each plugin's data epoch on. - vegas_scroll.live_refresh (kill switch), live_max_hz, live_min_interval, live_lead_screens; per-plugin core-owned vegas_live. Live elements are off under multi-display sync, in swap mode and with offscreen_prefetch off. - scripts/check_plugin.py checks the element contract (src/plugin_system/testing/vegas.py); test/fixtures/plugins/vegas-live-stub is a working example. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> * feat(vegas): live elements update in place while they scroll One background worker (src/vegas_mode/live_worker.py) redraws a plugin's live elements when its data epoch moves on (update listener) or on their refresh_hz, nearest the screen first, and hands changed pixels lock-free to the render thread, which copies them into the strip between frames (RenderPipeline.apply_live_patches, ScrollHelper.patch_columns): at most four patches or two screens of bytes a frame, no drawing or locks there. The worker takes over group prefetch once a live element is placed, runs inside the render gate, and is supervised. Update tick 1s while live elements exist. Web UI switch for live_refresh. OFFSCREEN_RENDERING.md describes what was built and why SegmentStrip was not needed. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
LED Matrix Web Interface V3
Modern, production web interface for controlling the LED Matrix display.
Overview
This directory contains the active V3 web interface with the following features:
- Real-time display preview via Server-Sent Events (SSE)
- Plugin management and configuration
- System monitoring and logs
- Modern, responsive UI
- RESTful API
Directory Structure
web_interface/
├── app.py # Main Flask application
├── start.py # Startup script
├── requirements.txt # Python dependencies
├── blueprints/ # Flask blueprints
│ ├── api_v3/ # API endpoints (package: config, display,
│ │ # plugins, system, backup, fonts, misc,
│ │ # wifi, starlark)
│ └── pages_v3.py # Page routes
├── tailwind/ # Tailwind config + input CSS (build inputs,
│ # not served; see "Styling" below)
├── templates/ # HTML templates
│ └── v3/
│ ├── base.html
│ └── partials/
└── static/ # CSS/JS assets
└── v3/
├── tailwind.css # GENERATED utility classes (committed)
├── plugin-frame.css # GENERATED styles for plugin web_ui/ iframes
├── app.css # hand-written: tokens, components, dark theme
├── app.js
├── manifest.json # PWA manifest
├── plugins_manager.js
├── icons/ # PWA / touch icons
├── js/ # Alpine, htmx, app shell, widgets, utils
└── vendor/ # codemirror, fontawesome
Styling (Tailwind CSS)
Templates and JS use Tailwind utility classes. The CSS for them is generated on a dev machine or in CI and committed, so the Pi never builds anything and the UI needs no CDN (it has to work in AP mode, with no internet).
static/v3/tailwind.cssholds the utilities. It is generated from the classes found intemplates/v3/,static/v3/**/*.jsandblueprints/, so it only contains what the UI uses.static/v3/app.cssis hand-written: theme tokens, base element styles, components (.btn,.card,.nav-tab, ...) and the dark theme ([data-theme="dark"] ...overrides).base.htmlloads it aftertailwind.css, so its rules win over utilities of equal specificity. Don't add utility classes to it; use the class and rebuild.static/v3/plugin-frame.cssstyles pluginweb_ui/fragments served by/v3/plugin-ui/<plugin>/web-ui/<file>in an iframe. Their markup lives in plugin repos, so it can't be scanned; its config safelists the common utility families instead.
After changing a template, a static JS file or anything in tailwind/,
rebuild and commit the CSS with your change:
python3 scripts/build_css.py # rewrites tailwind.css and plugin-frame.css
python3 scripts/build_css.py --check # what CI runs: fails if they are stale
No Node or npm is needed. The script downloads Tailwind's standalone CLI
(pinned version, SHA-256 checked) for your OS once and caches it outside
the repo (LEDMATRIX_TAILWIND_CACHE overrides where). CI runs --check
on every PR.
Where to change what:
- A class built at runtime (
`bg-${color}-100`) is invisible to the scanner: add it tosafelistintailwind/tailwind.config.js, or better, write the full class names in the code. - Colours, font sizes and shadows that differ from stock Tailwind (darker
gray text, emerald/amber button fills, token-based shadows) are set in the
themeoftailwind/tailwind.config.js. - Dark mode is the
data-theme="dark"attribute on<html>; thedark:variant is configured to match it.
Running the Web Interface
Standalone (Development)
From the project root:
python3 web_interface/start.py
As a Service (Production)
The web interface can run as a systemd service that starts automatically based on the web_display_autostart configuration setting:
sudo systemctl start ledmatrix-web
sudo systemctl enable ledmatrix-web # Start on boot
Accessing the Interface
Once running, access the web interface at:
- Local: http://localhost:5000
- Network: http://:5000
Configuration
The web interface reads configuration from:
config/config.json- Main configurationconfig/config_secrets.json- API keys and secrets
API Documentation
The V3 API is the api_v3 blueprint, registered at /api/v3/ in
app.py. For the complete
list and request/response formats, see
docs/REST_API_REFERENCE.md. Quick
reference for the most common endpoints:
Configuration
GET /api/v3/config/main- Get main configurationPOST /api/v3/config/main- Save main configurationGET /api/v3/config/secrets- Get secrets configurationPOST /api/v3/config/raw/main- Save raw main config (Config Editor)POST /api/v3/config/raw/secrets- Save raw secrets
Display & System Control
GET /api/v3/system/status- System statusPOST /api/v3/system/action- Control display (action body:start_display,stop_display,restart_display_service,restart_web_service,git_pull,reboot_system,shutdown_system,enable_autostart,disable_autostart)GET /api/v3/display/current- Current display frameGET /api/v3/display/on-demand/status- On-demand statusPOST /api/v3/display/on-demand/start- Trigger on-demand displayPOST /api/v3/display/on-demand/stop- Clear on-demand
Plugins
GET /api/v3/plugins/installed- List installed pluginsGET /api/v3/plugins/config?plugin_id=<id>- Get plugin configPOST /api/v3/plugins/config- Update plugin configurationGET /api/v3/plugins/schema?plugin_id=<id>- Get plugin schemaPOST /api/v3/plugins/toggle- Enable/disable pluginPOST /api/v3/plugins/install- Install from registryPOST /api/v3/plugins/install-from-url- Install from GitHub URLPOST /api/v3/plugins/uninstall- Uninstall pluginPOST /api/v3/plugins/update- Update plugin
Plugin Store
GET /api/v3/plugins/store/list- List available registry pluginsGET /api/v3/plugins/store/github-status- GitHub authentication statusPOST /api/v3/plugins/store/refresh- Refresh registry from GitHub
Real-time Streams (SSE)
SSE stream endpoints are defined directly on the Flask app in app.py
(stream_stats, stream_display, stream_logs, followed by their CSRF
exemption and rate-limit hookup), not on the api_v3 blueprint:
GET /api/v3/stream/stats- System statistics streamGET /api/v3/stream/display- Display preview streamGET /api/v3/stream/logs- Service logs stream
Development
When making changes to the web interface:
- Edit files in this directory
- Test changes by running
python3 web_interface/start.py - Restart the service if running:
sudo systemctl restart ledmatrix-web
Notes
- Templates and static files use the
v3/prefix to allow for future versions - The interface uses Flask blueprints for modular organization
- SSE streams provide real-time updates without polling