feat(editable-layers): EditModeCoordinateSystem abstraction aligned with deck.gl COORDINATE_SYSTEM

[Copilot]

All editable-layers edit modes hard-code turf.js (WGS84 geodesic) math, making them unusable with OrthographicView or any non-geographic coordinate system. This PR introduces an EditModeCoordinateSystem interface, integrates it with deck.gl's own COORDINATE_SYSTEM constants, and migrates key modes to use it, decoupling editing logic from geographic assumptions.

New: EditModeCoordinateSystem interface + implementations

The interface is named EditModeCoordinateSystem (not CoordinateSystem) to avoid collision with deck.gl's own CoordinateSystem type (-1 | 0 | 1 | 2 | 3 from @deck.gl/core), which describes rendering projection. EditModeCoordinateSystem describes geometric math for edit modes.

Four geometric primitives, consistent bearing convention (compass: 0°=north, CW, [-180°, 180°]):

export interface EditModeCoordinateSystem {
  distance(a: Position, b: Position): number;
  bearing(a: Position, b: Position): number;
  destination(origin: Position, distance: number, bearing: number): Position;
  midpoint(a: Position, b: Position): Position;
}

// WGS84 — wraps turf.js, default/existing behavior unchanged
export const geoCoordinateSystem = new GeoCoordinateSystem();

// Euclidean — Pythagorean distance, atan2 bearing, trig destination
export const cartesianCoordinateSystem = new CartesianCoordinateSystem();

Integration with deck.gl COORDINATE_SYSTEM

A new fromDeckCoordinateSystem() utility maps deck.gl's COORDINATE_SYSTEM enum to the correct math implementation:

deck.gl constant	Math used
COORDINATE_SYSTEM.LNGLAT / DEFAULT / LNGLAT_OFFSETS	GeoCoordinateSystem
COORDINATE_SYSTEM.CARTESIAN / METER_OFFSETS	CartesianCoordinateSystem

EditableGeoJsonLayer.getModeProps() now automatically derives coordinateSystem from the layer's own this.props.coordinateSystem (the standard deck.gl layer prop) via fromDeckCoordinateSystem(). Users just set coordinateSystem={COORDINATE_SYSTEM.CARTESIAN} on the layer and edit modes automatically use Euclidean math — no separate configuration needed.

ModeProps extended

type ModeProps<TData> = {
  // ...existing fields
  coordinateSystem?: EditModeCoordinateSystem; // auto-derived from layer's coordinateSystem prop
};

Modes migrated

• translateFromCenter — removes @turf/rhumb-bearing/distance/destination in favour of the coordinate system abstraction
• TranslateMode — uses props.coordinateSystem for drag distance/bearing and translateFromCenter
• MeasureDistanceMode — uses props.coordinateSystem for segment distance and midpoint tooltips

Exports

EditModeCoordinateSystem, GeoCoordinateSystem, CartesianCoordinateSystem, geoCoordinateSystem, cartesianCoordinateSystem, getEditModeCoordinateSystem, fromDeckCoordinateSystem are all exported from the package root.

Remaining modes (RotateMode, ScaleMode, circle/measurement modes) still call turf directly; follow-up PRs can migrate them one-by-one using the same pattern.

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[charlieforward9]

@copilot It feels like we are not using enough from https://deck.gl/docs/developer-guide/coordinate-systems - this should be better shared

[Copilot]

@copilot It feels like we are not using enough from https://deck.gl/docs/developer-guide/coordinate-systems - this should be better shared

Done in commit 4533e6d.

Three changes align with deck.gl's coordinate system:

1. Renamed CoordinateSystem → EditModeCoordinateSystem to avoid the name collision with @deck.gl/core's own CoordinateSystem type (-1 | 0 | 1 | 2 | 3).

2. Added fromDeckCoordinateSystem() that maps deck.gl's COORDINATE_SYSTEM enum directly to the right math implementation:

   • COORDINATE_SYSTEM.CARTESIAN / METER_OFFSETS → CartesianCoordinateSystem
   • COORDINATE_SYSTEM.LNGLAT / LNGLAT_OFFSETS / DEFAULT → GeoCoordinateSystem

3. EditableGeoJsonLayer.getModeProps() now auto-derives coordinateSystem from this.props.coordinateSystem (the standard deck.gl layer prop) via fromDeckCoordinateSystem(). So users just set coordinateSystem={COORDINATE_SYSTEM.CARTESIAN} on the layer and edit modes automatically use Euclidean math — no separate configuration needed.

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