Marker occlusion tester

Author: xeolabs

packages/sdk/src/viewing/viewer/getElementCssSize.ts

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+/**
+ * Returns an element's visible CSS-pixel size.
+ *
+ * Pointer events that callers convert with `clientX/Y - rect.left/top` are in
+ * `getBoundingClientRect()` coordinates. Use the same dimensions when turning
+ * those coordinates into NDC or projecting world points back into overlay
+ * space. Fall back to layout metrics for hidden/jsdom elements whose rect has
+ * not been populated.
+ *
+ * @internal
+ */
+export function getElementCssSize(element: HTMLElement): { width: number; height: number } {
+  const rect = element.getBoundingClientRect();
+  const width = finitePositive(rect.width)
+    ? rect.width
+    : fallbackDimension(element.clientWidth, element.offsetWidth);
+  const height = finitePositive(rect.height)
+    ? rect.height
+    : fallbackDimension(element.clientHeight, element.offsetHeight);
+  return {width, height};
+}
+
+function finitePositive(value: number): boolean {
+  return Number.isFinite(value) && value > 0;
+}
+
+function fallbackDimension(client: number, offset: number): number {
+  if (finitePositive(client)) return client;
+  if (finitePositive(offset)) return offset;
+  return 1;
+}

packages/sdk/src/viewing/viewer/tests/getElementCssSize.test.ts

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+import {getElementCssSize} from "../getElementCssSize";
+
+describe("getElementCssSize", () => {
+  test("prefers bounding-client-rect dimensions", () => {
+    const element = {
+      getBoundingClientRect: () => ({width: 123.5, height: 45.25}),
+      clientWidth: 100,
+      clientHeight: 40,
+      offsetWidth: 90,
+      offsetHeight: 30,
+    } as HTMLElement;
+
+    expect(getElementCssSize(element)).toEqual({width: 123.5, height: 45.25});
+  });
+
+  test("falls back to layout dimensions when the rect is empty", () => {
+    const element = {
+      getBoundingClientRect: () => ({width: 0, height: 0}),
+      clientWidth: 100,
+      clientHeight: 40,
+      offsetWidth: 90,
+      offsetHeight: 30,
+    } as HTMLElement;
+
+    expect(getElementCssSize(element)).toEqual({width: 100, height: 40});
+  });
+});

packages/sdk/src/viewing/webGLRenderer/MarkerOcclusionResult.ts

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+import type {Vec2, Vec3} from "../../base/math/vector";
+import type {MarkerOcclusionMarker, MarkerOcclusionMode} from "./MarkerOcclusionTesterParams";
+
+/**
+ * Visibility result for a marker after one occlusion update.
+ */
+export interface MarkerOcclusionResult {
+  /** Stable ID from {@link MarkerOcclusionMarker.id}. */
+  markerId: string;
+
+  /** Marker input that produced this result. */
+  marker: MarkerOcclusionMarker;
+
+  /** Backend used for this result. */
+  mode: Exclude<MarkerOcclusionMode, "auto">;
+
+  /** `true` when the marker should be shown after frustum and hysteresis rules. */
+  visible: boolean;
+
+  /** Raw occlusion result for this update before hysteresis is applied. */
+  occluded: boolean;
+
+  /** `true` when the marker projects inside the view frustum. */
+  inFrustum: boolean;
+
+  /** Canvas-space marker position in CSS pixels, or `null` when not projectable. */
+  canvasPos: Vec2 | null;
+
+  /** World-space ray origin used by the occlusion test, or `null` when skipped. */
+  rayOrigin: Vec3 | null;
+
+  /** World-space ray direction used by the occlusion test, or `null` when skipped. */
+  rayDir: Vec3 | null;
+
+  /** Distance from ray origin to marker along {@link rayDir}, or `null` when skipped. */
+  distanceToMarker: number | null;
+
+  /** Object ID of the occluder, if any. */
+  occluderObjectId: string | null;
+
+  /** Mesh ID of the occluder, if any. */
+  occluderMeshId: string | null;
+}