Mvt
Per-glyph baseline-following text label for one MVT LINESTRING feature. Each render-pass projects the polyline's geographic waypoints into screen space, runs the arc-length placer to produce one MvtCurvedTextPlacer.GlyphRun per repeat, then emits a single- character Label per glyph with its own rotation matching the local tangent.
This is the "snake-along-the-curve" treatment that Mapbox's symbol-placement: line implements — visible improvement over MvtLabelGroup's single line-center label on sinuous features (rivers, winding roads). Repeats every repeatGapPx pixels of arc length so a long feature carries multiple legibility points.
Collision: each Label participates in MvtLabelGroup's screen-space collision via its own bounding box. Per-glyph collision would tear adjacent characters of the same word apart, so a single run is treated as one collision candidate via the average pixel size and width across its glyphs; callers can pass these to the global collision pass.
Construction is cheap (just holds inputs). The expensive work — projection, the arc-length walk and glyph placement — happens in doRender. The per-glyph Labels and the projection Vec2s are pooled and mutated in place across frames (the same persistent-Label pattern MvtLabelGroup uses), so steady-state per-frame allocation is bounded to the placer's transient output rather than the ~120 short-lived objects/label/frame a fresh-allocate path would churn.
Constructors
Properties
Per-character pixel widths produced by the source font's earth.worldwind.render.Font.measureChars.
Set each frame by MvtLabelCollider's line collision pass BEFORE render: false culls this label. Defaults true so labels still show if no pass runs (the pass sets all false, then survivors true).