refactor: own application request operations and surface caches

src/app/surfaceServices.js

@@ -0,0 +1,37 @@
+import { createTerrainHeights } from '../services/terrainHeights.js';
+import { createGroundFloor } from '../services/groundFloor.js';
+import { createMeshFloorSampler } from '../services/meshFloorSampler.js';
+import { createGroundSnap } from '../services/groundSnap.js';
+import { createFireAnchors } from '../layers/firms/anchors.js';
+
+/** Own the DEM, coarse floors and mesh samples used by one application. */
+export function createSurfaceServices({
+  terrainSource,
+  signal,
+  eventTarget = globalThis.window,
+}) {
+  const terrain = createTerrainHeights({ source: terrainSource, signal });
+  const groundFloor = createGroundFloor({ terrain, signal });
+  const meshFloor = createMeshFloorSampler({
+    groundFloor,
+    signal,
+    eventTarget,
+  });
+  return Object.freeze({
+    terrain,
+    groundFloor,
+    meshFloor,
+    groundSnap: Object.freeze({
+      createGroundSnap: () => createGroundSnap({ groundFloor }),
+    }),
+    anchors: createFireAnchors(groundFloor),
+    controlServices: Object.freeze({
+      cachedGroundFloor: groundFloor.cachedGroundFloor,
+      cachedMeshFloor: groundFloor.cachedMeshFloor,
+      GROUND_FLOOR_LIFT_M: groundFloor.GROUND_FLOOR_LIFT_M,
+      meshFloorPreferred: groundFloor.meshFloorPreferred,
+      warmGroundFloor: groundFloor.warmGroundFloor,
+      sampleMeshFloorCells: meshFloor.sampleMeshFloorCells,
+    }),
+  });
+}