Add existing to tracked

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

@@ -0,0 +1,186 @@
+// @ts-check
+
+import BufferPrimitive from "./BufferPrimitive.js";
+import assert from "../Core/assert.js";
+import BufferPrimitiveCollection from "./BufferPrimitiveCollection.js";
+import defined from "../Core/defined.js";
+
+/** @import { TypedArray, TypedArrayConstructor } from "../Core/globalTypes.js"; */
+/** @import BufferPolylineCollection from "./BufferPolylineCollection.js"; */
+
+const { ERR_RESIZE, ERR_CAPACITY } = BufferPrimitiveCollection.Error;
+
+/**
+ * View bound to the underlying buffer data of a {@link BufferPolylineCollection}.
+ *
+ * <p>BufferPolyline instances are {@link https://en.wikipedia.org/wiki/Flyweight_pattern|flyweights}:
+ * a single BufferPolyline instance can be temporarily bound to any conceptual
+ * "polyline" in a BufferPolylineCollection, allowing very large collections to be
+ * iterated and updated with a minimal memory footprint.</p>
+ *
+ * Represented as two (2) or more positions.
+ *
+ * @see BufferPolylineCollection
+ * @see BufferPolylineMaterial
+ * @see BufferPrimitive
+ * @extends BufferPrimitive
+ * @experimental This feature is not final and is subject to change without Cesium's standard deprecation policy.
+ */
+class BufferPolyline extends BufferPrimitive {
+  /**
+   * @type {BufferPolylineCollection}
+   * @ignore
+   */
+  _collection = null;
+
+  /** @ignore */
+  static Layout = {
+    ...BufferPrimitive.Layout,
+
+    /**
+     * Offset in position array to first vertex in polyline, number of VEC3 elements.
+     * @type {number}
+     * @ignore
+     */
+    POSITION_OFFSET_U32: BufferPrimitive.Layout.__BYTE_LENGTH,
+
+    /**
+     * Count of positions (vertices) in this polyline, number of VEC3 elements.
+     * @type {number}
+     * @ignore
+     */
+    POSITION_COUNT_U32: BufferPrimitive.Layout.__BYTE_LENGTH + 4,
+
+    /**
+     * @type {number}
+     * @ignore
+     */
+    __BYTE_LENGTH: BufferPrimitive.Layout.__BYTE_LENGTH + 8,
+  };
+
+  /////////////////////////////////////////////////////////////////////////////
+  // LIFECYCLE
+
+  /**
+   * Copies data from source polyline to result. If the result polyline is not
+   * new (the last polyline in the collection) then source and result polylines
+   * must have the same vertex counts.
+   *
+   * @param {BufferPolyline} polyline
+   * @param {BufferPolyline} result
+   * @return {BufferPolyline}
+   * @override
+   */
+  static clone(polyline, result) {
+    super.clone(polyline, result);
+    result.setPositions(polyline.getPositions());
+    return result;
+  }
+
+  /////////////////////////////////////////////////////////////////////////////
+  // GEOMETRY
+
+  /**
+   * Offset in collection position array to first vertex in polyline, number
+   * of VEC3 elements.
+   *
+   * @type {number}
+   * @readonly
+   * @ignore
+   */
+  get vertexOffset() {
+    return this._getUint32(BufferPolyline.Layout.POSITION_OFFSET_U32);
+  }
+
+  /**
+   * Count of positions (vertices) in this polyline, number of VEC3 elements.
+   *
+   * @type {number}
+   * @readonly
+   */
+  get vertexCount() {
+    return this._getUint32(BufferPolyline.Layout.POSITION_COUNT_U32);
+  }
+
+  /**
+   * Returns an array view of this polyline's vertex positions. If 'result'
+   * argument is given, vertex positions are written to that array and returned.
+   * Otherwise, returns an ArrayView on collection memory — changes to this array
+   * will not trigger render updates, which requires `.setPositions()`.
+   *
+   * @param {TypedArray} [result]
+   * return {TypedArray}
+   */
+  getPositions(result) {
+    const { vertexOffset, vertexCount } = this;
+    const positionView = this._collection._positionView;
+
+    if (!defined(result)) {
+      const byteOffset =
+        positionView.byteOffset +
+        vertexOffset * 3 * positionView.BYTES_PER_ELEMENT;
+      const TypedArray = /** @type {TypedArrayConstructor} */ (
+        positionView.constructor
+      );
+      return new TypedArray(
+        /** @type {ArrayBuffer} */ (positionView.buffer),
+        byteOffset,
+        vertexCount * 3,
+      );
+    }
+
+    for (let i = 0; i < vertexCount; i++) {
+      result[i * 3] = positionView[(vertexOffset + i) * 3];
+      result[i * 3 + 1] = positionView[(vertexOffset + i) * 3 + 1];
+      result[i * 3 + 2] = positionView[(vertexOffset + i) * 3 + 2];
+    }
+    return result;
+  }
+
+  /** @param {TypedArray} positions */
+  setPositions(positions) {
+    const collection = this._collection;
+    const vertexOffset = this.vertexOffset;
+    const srcCount = this.vertexCount;
+    const dstCount = positions.length / 3;
+    const collectionCount = collection._positionCount + dstCount - srcCount;
+
+    //>>includeStart('debug', pragmas.debug);
+    assert(srcCount === dstCount || this._isResizable(), ERR_RESIZE);
+    assert(collectionCount <= collection.vertexCountMax, ERR_CAPACITY);
+    //>>includeEnd('debug');
+
+    collection._positionCount = collectionCount;
+    this._setUint32(BufferPolyline.Layout.POSITION_COUNT_U32, dstCount);
+
+    const positionView = collection._positionView;
+    for (let i = 0; i < dstCount; i++) {
+      positionView[(vertexOffset + i) * 3] = positions[i * 3];
+      positionView[(vertexOffset + i) * 3 + 1] = positions[i * 3 + 1];
+      positionView[(vertexOffset + i) * 3 + 2] = positions[i * 3 + 2];
+    }
+
+    this._dirty = true;
+    collection._makeDirtyBoundingVolume();
+  }
+
+  /////////////////////////////////////////////////////////////////////////////
+  // DEBUG
+
+  /**
+   * Returns a JSON-serializable object representing the polyline. This encoding
+   * is not memory-efficient, and should generally be used for debugging and
+   * testing.
+   *
+   * @returns {Object} JSON-serializable object.
+   * @override
+   */
+  toJSON() {
+    return {
+      ...super.toJSON(),
+      positions: Array.from(this.getPositions()),
+    };
+  }
+}
+
+export default BufferPolyline;