Visualization

FSBar.Viz renders BAR game state through a declarative scene API built on SkiaSharp + Silk.NET (via the in-house SkiaViewer package).

Entry points

• *GameViz* — live attach to a BarClient. Opens a window, streams frames, supports hotkey overlays.
• *SceneBuilder* — pure function GameState -> Scene. Used by the Hub Viewer tab, preview thumbnails, and screenshots.
• *PreviewSession* — headless framebuffer render for thumbnails and CI screenshots.

Unit glyph language

FSBar.Viz.UnitGlyph is the information-dense renderer behind VizConfig.UseGlyphRenderer (default true). Every unit draws as:

• Shape — movement class (ground / hover / ship / air / building)
• Fill — team color
• Stroke — faction (arm / core / legion / …)
• Tier badge — T1 / T2 / T3 / commander
• Label — 2- or 3-char code from the committed UnitLabels.generated.fs table
• Facing pip — triangle pointing along HeadingRadians (suppressed for buildings)

Hotkeys layer additional overlays on the glyph: W weapon ranges, L sight, C command queue, N full names, P style configurator.

Unit display adapter

UnitDisplayAdapter is the single constructor for UnitDisplay values across every surface (live viewer, encyclopedia, style preview). Three entry points:

UnitDisplayAdapter.ofTrackedUnit defCache teamId unitId trackedUnit
UnitDisplayAdapter.ofTrackedEnemy defCache enemyId trackedEnemy
UnitDisplayAdapter.ofEncyclopediaEntry entry pinnedFootprint

This guarantees that a glyph in the Viewer matches the glyph in the Units tab byte-for-byte.

Style configurator

Press P in the live viewer (or open the Hub Style tab) to toggle a side panel exposing every VizConfig / UnitGlyphStyle attribute via typed descriptors:

• ConfigDescriptors.all — static registry (key, label, category, inputKind, get/set, default, range). Single source of truth for what's editable.
• ConfigPanel — declarative rendering + mouse/scroll input.
• StylePreset — JSON persistence under viz-presets/<name>.json (gitignored).

Adding a new visual attribute means appending one entry to ConfigDescriptors.all; the panel and preset roundtrip pick it up automatically.

Synthetic data pipeline

FSBar.SyntheticData.Scenes produces deterministic Scene values without an engine. Used by:

• Every FSBar.Viz baseline / snapshot test
• The Hub Units tab glyph preview
• The Style tab's live preview canvas

Notes

• GPU backend (GRContext) segfaults in this environment. The renderer uses a raster SKSurface + GL texture upload instead — see src/FSBar.Viz/Viewer.fs.
• Graphical engine runs in windowed mode only. EngineLauncher forces Fullscreen=0 in per-session springsettings.cfg.
• Throttle viz updates to ~60 fps when driving a high-speed game loop — calling onFrame on every engine step at 10× speed will pin a core.

Regenerating unit labels

When the BarData package bumps, regenerate the committed label table:

dotnet fsi src/FSBar.Viz/scripts/gen-unit-labels.fsx

The generator exits non-zero if an existing label would silently change (SC-006 tripwire).