Add existing to tracked

node_modules/@cesium/engine/Source/Scene/HeightReference.js

@@ -0,0 +1,89 @@
+// @ts-check
+
+/**
+ * Represents the position relative to the terrain.
+ *
+ * @enum {number}
+ */
+const HeightReference = {
+  /**
+   * The position is absolute.
+   * @type {number}
+   * @constant
+   */
+  NONE: 0,
+
+  /**
+   * The position is clamped to the terrain and 3D Tiles. When clamping to 3D Tilesets such as photorealistic 3D Tiles, ensure the tileset has {@link Cesium3DTileset#enableCollision} set to <code>true</code>. Otherwise, the entity may not be correctly clamped to the tileset surface.
+   * @type {number}
+   * @constant
+   */
+  CLAMP_TO_GROUND: 1,
+
+  /**
+   * The position height is the height above the terrain and 3D Tiles.
+   * @type {number}
+   * @constant
+   */
+  RELATIVE_TO_GROUND: 2,
+
+  /**
+   * The position is clamped to terain.
+   * @type {number}
+   * @constant
+   */
+  CLAMP_TO_TERRAIN: 3,
+
+  /**
+   * The position height is the height above terrain.
+   * @type {number}
+   * @constant
+   */
+  RELATIVE_TO_TERRAIN: 4,
+
+  /**
+   * The position is clamped to 3D Tiles.
+   * @type {number}
+   * @constant
+   */
+  CLAMP_TO_3D_TILE: 5,
+
+  /**
+   * The position height is the height above 3D Tiles.
+   * @type {number}
+   * @constant
+   */
+  RELATIVE_TO_3D_TILE: 6,
+};
+
+Object.freeze(HeightReference);
+
+export default HeightReference;
+
+/**
+ * Returns true if the height should be clamped to the surface
+ * @param {HeightReference} heightReference
+ * @returns true if the height should be clamped to the surface
+ * @private
+ */
+export function isHeightReferenceClamp(heightReference) {
+  return (
+    heightReference === HeightReference.CLAMP_TO_GROUND ||
+    heightReference === HeightReference.CLAMP_TO_3D_TILE ||
+    heightReference === HeightReference.CLAMP_TO_TERRAIN
+  );
+}
+
+/**
+ * Returns true if the height should be offset relative to the surface
+ * @param {HeightReference} heightReference
+ * @returns true if the height should be offset relative to the surface
+ * @private
+ */
+export function isHeightReferenceRelative(heightReference) {
+  return (
+    heightReference === HeightReference.RELATIVE_TO_GROUND ||
+    heightReference === HeightReference.RELATIVE_TO_3D_TILE ||
+    heightReference === HeightReference.RELATIVE_TO_TERRAIN
+  );
+}