Start cleanup

packages/engine/Source/Scene/ClippingPolygon.js

@@ -1,37 +1,71 @@
-import ArcType from "../Core/ArcType.js";
+import Check from "../Core/Check.js";
+import Cartesian3 from "../Core/Cartesian3.js";
+import Cartographic from "../Core/Cartographic.js";
 import defaultValue from "../Core/defaultValue.js";
 import Ellipsoid from "../Core/Ellipsoid.js";
+import CesiumMath from "../Core/Math.js";
 import PolygonGeometry from "../Core/PolygonGeometry.js";
+import Rectangle from "../Core/Rectangle.js";
 
 /**
- * No holes or complex polygons. TODO
+ * A geodesic polygon to be used with {@link ClippingPlaneCollection} for selectively hiding regions in a model, a 3D tileset, or the globe.
  * @alias ClippingPolygon
  * @constructor
  *
- * @param {object} [options] Object with the following properties:
+ * @param {object} options Object with the following properties:
+ * @param {PolygonHierarchy} options.hierarchy TODO
+ * @param {Ellipsoid} [options.ellipsoid=Ellipsoid.WGS84]
  *
  * TODO: Example
  */
 function ClippingPolygon(options) {
-  options = defaultValue(options, defaultValue.EMPTY_OBJECT);
-
   //>>includeStart('debug', pragmas.debug);
-  // TODO: Check
-  // TODO: At least three positions
+  Check.typeOf.object("options", options);
+  Check.typeOf.object("options.hierarchy", options.hierarchy);
+  Check.typeOf.number.greaterThanOrEquals(
+    "options.hierarchy.positions",
+    options.hierarchy.positions,
+    3
+  );
   //>>includeEnd('debug');
 
   this.ellipsoid = defaultValue(options.ellipsoid, Ellipsoid.WGS84);
-  this.arcType = defaultValue(options.arcType, ArcType.GEODESIC);
-  this.positions = options.positions;
-
-  this._rectangle = PolygonGeometry.computeRectangleFromPositions(
-    this.positions,
-    this.ellipsoid,
-    this.arcType
-  ); // TODO:
+  this.hierarchy = options.hierarchy;
 }
 
-Object.defineProperties(ClippingPolygon.prototype, {});
+Object.defineProperties(ClippingPolygon.prototype, {
+  /**
+   * Returns the total number of positions in the polygon, include any holes.
+   *
+   * @memberof ClippingPolygon.prototype
+   * @type {number}
+   * @readonly
+   */
+  length: {
+    get: function () {
+      const hierarchy = this.hierarchy;
+      let length = hierarchy.positions.length;
+      let holes = hierarchy.holes;
+      while (holes.positions.length > 0) {
+        length += holes.positions.length;
+        holes = holes.holes;
+      }
+      return length;
+    },
+  },
+  /**
+   * Returns the outer ring of positions.
+   *
+   * @memberof ClippingPolygon.prototype
+   * @type {Cartesian3[]}
+   * @readonly
+   */
+  outerPositions: {
+    get: function () {
+      return this.hierarchy.positions;
+    },
+  },
+});
 
 /**
  * Clones the ClippingPolygon without setting its ownership.
@@ -44,14 +78,82 @@ ClippingPolygon.clone = function (clippingPlane, result) {
 };
 
 /**
- * Computes a rectangle which encloses the polygon defined by the list of positions, including cases over the international date line and the poles.
+ * Computes a cartographic rectangle which encloses the polygon defined by the list of positions, including cases over the international date line and the poles.
  *
  * @param {Rectangle} [result] An object in which to store the result.
  *
  * @returns {Rectangle} The result rectangle
  */
 ClippingPolygon.prototype.computeRectangle = function (result) {
-  return this._rectangle; // TODO
+  return PolygonGeometry.computeRectangleFromPositions(
+    this.hierarchy.positions,
+    this.ellipsoid,
+    undefined,
+    result
+  );
+};
+
+const scratchRectangle = new Rectangle();
+const spherePointScratch = new Cartesian3();
+/**
+ * Computes a rectangle with the spherical extents that encloses the polygon defined by the list of positions, including cases over the international date line and the poles.
+ *
+ * @private
+ *
+ * @param {Rectangle} [result] An object in which to store the result.
+ * @returns {Rectangle} The result rectangle with spherical extents.
+ */
+ClippingPolygon.prototype.computeSphericalExtents = function (result) {
+  const rectangle = PolygonGeometry.computeRectangleFromPositions(
+    this.hierarchy.positions,
+    this.ellipsoid,
+    undefined,
+    scratchRectangle
+  );
+
+  let spherePoint = Cartographic.toCartesian(
+    Rectangle.southwest(rectangle),
+    this.ellipsoid,
+    spherePointScratch
+  );
+
+  // Project into plane with vertical for latitude
+  let magXY = Math.sqrt(
+    spherePoint.x * spherePoint.x + spherePoint.y * spherePoint.y
+  );
+
+  // Use fastApproximateAtan2 for alignment with shader
+  let sphereLatitude = CesiumMath.fastApproximateAtan2(magXY, spherePoint.z);
+  let sphereLongitude = CesiumMath.fastApproximateAtan2(
+    spherePoint.x,
+    spherePoint.y
+  );
+
+  result.south = sphereLatitude;
+  result.west = sphereLongitude;
+
+  spherePoint = Cartographic.toCartesian(
+    Rectangle.northeast(rectangle),
+    this.ellipsoid,
+    spherePointScratch
+  );
+
+  // Project into plane with vertical for latitude
+  magXY = Math.sqrt(
+    spherePoint.x * spherePoint.x + spherePoint.y * spherePoint.y
+  );
+
+  // Use fastApproximateAtan2 for alignment with shader
+  sphereLatitude = CesiumMath.fastApproximateAtan2(magXY, spherePoint.z);
+  sphereLongitude = CesiumMath.fastApproximateAtan2(
+    spherePoint.x,
+    spherePoint.y
+  );
+
+  result.north = sphereLatitude;
+  result.east = sphereLongitude;
+
+  return result;
 };
 
 export default ClippingPolygon;