Spherical lines, polygons and shared queries

Shared GeoJSON circle, line and fill layers survive globe projection changes and support creation, order, paint, filters and visibility on the sphere. Browser main/strict Worker, native-library scripts and desktop scripts use the same calls. Naming follows the MapLibre Map API, with paint conventions from the MapLibre layer specification; SqsMap implements the engine independently.

import { map } from 'sqsmap';
const capabilities = await map.sqs.getCapabilities();
if (!capabilities.globeGeoJsonSurfaceLayers || !capabilities.globeGeoJsonSurfaceQueries)
  throw new Error('Spherical line and fill support is required');
map.setProjection({ type: 'globe' });
map.addSource('route-data', { type: 'geojson', data: {
  type: 'Feature', id: 7, properties: { name: 'Example route' },
  geometry: { type: 'LineString', coordinates: [[179, 38], [183, 38]] }
}});
map.addLayer({ id: 'route', type: 'line', source: 'route-data', paint: {
  'line-color': '#0080ff', 'line-width': 12
}});
await map.sqs.flush({ render: true });
const point = await map.project([181, 38]);
const hits = await map.queryRenderedFeatures(point, { layers: ['route'] });
console.log(hits);

Complete common script · Complete HTML/CSS/JavaScript. All visibility, paint, order, width, projection, click and destruction handlers use public APIs; controls read actual map state. Copy the whole file with its matching SDK files and serve it over HTTP. This example owns its data and uses no external basemap; external maps still require their applicable credits.

Original longitude/latitude enters spherical projection without Mercator latitude clamping. Polygons retain holes, MultiPolygon and parent collection identity, including polar regions and world copies such as 181°. GeoJSON edges interpolate in the supplied longitude/latitude plane. Cross the dateline with continuous copies (179 to 183) or split geometry; 170 to -170 is not silently converted to a shortest great-circle edge. Curves subdivide against logical-pixel error and clip at spherical visibility boundaries. Line width and the 1-pixel fill-outline-color boundary scale with DPR.

Drawing and queries use the same visible triangles. Point/box queries support selected layers, filters, feature state and topmost order, preserving original properties, complete parent geometry, source/layer instances and historical snapshots. Reordering changes both display and hits; paint changes do not rewrite source properties. A line layer also strokes Polygon geometry from mixed sources. To draw only routes, add filter: ['==', ['geometry-type'], 'LineString'].

This is a 2D style overlay on the earth surface. Arbitrary 3D occlusion, elevated geometry, spherical terrain and symbol/extrusion layers remain separate work. Unsupported paint/layout rejects explicitly: spherical lines currently support line-color, line-width and line-opacity; caps are butt with shared round joins; dashes, gradients and configurable caps/joins remain pending.

Each spherical line/fill draw or query shares 500,000 projection/triangle work items; raw overlays contain at most 100,000 coordinates. Exhaustion fails with RESOURCE_LIMIT as a whole. Existing 1000-item/8 MiB query output and 100,000-display-feature budgets still apply. Narrow data, area or layers before retrying; no silent truncation. Current-frame receipts compare pose, density and geometry, so old content cannot certify new order or paint.

The same 19-assertion script runs in actual one-shot/persistent native sessions, main/strict Worker at DPR1/2 and Linux desktop at DPR2/1.25. Separate model checks cover holes, poles, date-line copies, back-surface visibility and budgets. Actual pixel evidence covers colors, holes, width and order on software GPUs. Windows/macOS, physical mobile devices and formal release remain separate acceptance.

See spherical circles, pointer input and shared-map reference.