import MockTerrainProvider from "../MockTerrainProvider.js";
import TerrainTileProcessor from "../TerrainTileProcessor.js";
import { Cartesian2 } from "../../Source/Cesium.js";
import { Cartesian3 } from "../../Source/Cesium.js";
import { GeographicProjection } from "../../Source/Cesium.js";
import { HeightmapTerrainData } from "../../Source/Cesium.js";
import { Intersect } from "../../Source/Cesium.js";
import { Math as CesiumMath } from "../../Source/Cesium.js";
import { Camera } from "../../Source/Cesium.js";
import { GlobeSurfaceTileProvider } from "../../Source/Cesium.js";
import { ImageryLayerCollection } from "../../Source/Cesium.js";
import { QuadtreePrimitive } from "../../Source/Cesium.js";
import { SceneMode } from "../../Source/Cesium.js";
import { TerrainFillMesh } from "../../Source/Cesium.js";
import { TileBoundingRegion } from "../../Source/Cesium.js";
import { TileSelectionResult } from "../../Source/Cesium.js";

describe("Scene/TerrainFillMesh", function () {
  var processor;
  var scene;
  var camera;
  var frameState;
  var imageryLayerCollection;
  var surfaceShaderSet;
  var mockTerrain;
  var tileProvider;
  var quadtree;
  var rootTiles;

  var center;
  var west;
  var south;
  var east;
  var north;
  var southwest;
  var southeast;
  var northwest;
  var northeast;

  beforeEach(function () {
    scene = {
      mapProjection: new GeographicProjection(),
      drawingBufferWidth: 1000,
      drawingBufferHeight: 1000,
    };

    camera = new Camera(scene);

    frameState = {
      frameNumber: 0,
      passes: {
        render: true,
      },
      camera: camera,
      fog: {
        enabled: false,
      },
      context: {
        drawingBufferWidth: scene.drawingBufferWidth,
        drawingBufferHeight: scene.drawingBufferHeight,
      },
      mode: SceneMode.SCENE3D,
      commandList: [],
      cullingVolume: jasmine.createSpyObj("CullingVolume", [
        "computeVisibility",
      ]),
      afterRender: [],
    };

    frameState.cullingVolume.computeVisibility.and.returnValue(
      Intersect.INTERSECTING
    );

    imageryLayerCollection = new ImageryLayerCollection();
    surfaceShaderSet = jasmine.createSpyObj("SurfaceShaderSet", [
      "getShaderProgram",
    ]);
    mockTerrain = new MockTerrainProvider();
    tileProvider = new GlobeSurfaceTileProvider({
      terrainProvider: mockTerrain,
      imageryLayers: imageryLayerCollection,
      surfaceShaderSet: surfaceShaderSet,
    });
    quadtree = new QuadtreePrimitive({
      tileProvider: tileProvider,
    });

    processor = new TerrainTileProcessor(
      frameState,
      mockTerrain,
      imageryLayerCollection
    );
    processor.mockWebGL();

    quadtree.render(frameState);
    rootTiles = quadtree._levelZeroTiles;

    center =
      rootTiles[0].northeastChild.southwestChild.northeastChild.southwestChild;
    west = center.findTileToWest(rootTiles);
    south = center.findTileToSouth(rootTiles);
    east = center.findTileToEast(rootTiles);
    north = center.findTileToNorth(rootTiles);
    southwest = west.findTileToSouth(rootTiles);
    southeast = east.findTileToSouth(rootTiles);
    northwest = west.findTileToNorth(rootTiles);
    northeast = east.findTileToNorth(rootTiles);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            15.0,
            16.0,
            17.0,
            22.0,
            23.0,
            24.0,
            29.0,
            30.0,
            31.0,
          ]),
        }),
        west
      )
      .createMeshWillSucceed(west);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            31.0,
            32.0,
            33.0,
            38.0,
            39.0,
            40.0,
            45.0,
            46.0,
            47.0,
          ]),
        }),
        south
      )
      .createMeshWillSucceed(south);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            19.0,
            20.0,
            21.0,
            26.0,
            27.0,
            28.0,
            33.0,
            34.0,
            35.0,
          ]),
        }),
        east
      )
      .createMeshWillSucceed(east);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            3.0,
            4.0,
            5.0,
            10.0,
            11.0,
            12.0,
            17.0,
            18.0,
            19.0,
          ]),
        }),
        north
      )
      .createMeshWillSucceed(north);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            29.0,
            30.0,
            31.0,
            36.0,
            37.0,
            38.0,
            43.0,
            44.0,
            45.0,
          ]),
        }),
        southwest
      )
      .createMeshWillSucceed(southwest);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            33.0,
            34.0,
            35.0,
            40.0,
            41.0,
            42.0,
            47.0,
            48.0,
            49.0,
          ]),
        }),
        southeast
      )
      .createMeshWillSucceed(southeast);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            1.0,
            2.0,
            3.0,
            8.0,
            9.0,
            10.0,
            15.0,
            16.0,
            17.0,
          ]),
        }),
        northwest
      )
      .createMeshWillSucceed(northwest);

    mockTerrain
      .requestTileGeometryWillSucceedWith(
        new HeightmapTerrainData({
          width: 3,
          height: 3,
          createdByUpsampling: false,
          buffer: new Float32Array([
            5.0,
            6.0,
            7.0,
            12.0,
            13.0,
            14.0,
            19.0,
            20.0,
            21.0,
          ]),
        }),
        northeast
      )
      .createMeshWillSucceed(northeast);
  });

  describe("updateFillTiles", function () {
    it("does nothing if no rendered tiles are provided", function () {
      expect(function () {
        TerrainFillMesh.updateFillTiles(tileProvider, [], frameState);
      }).not.toThrow();
    });

    it("propagates edges and corners to an unloaded tile", function () {
      var tiles = [
        center,
        west,
        south,
        east,
        north,
        southwest,
        southeast,
        northwest,
        northeast,
      ];

      tiles.forEach(mockTerrain.createMeshWillSucceed.bind(mockTerrain));

      return processor.process(tiles).then(function () {
        tiles.forEach(markRendered);

        TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);

        var fill = center.data.fill;
        expect(fill).toBeDefined();
        expect(fill.westTiles).toEqual([west]);
        expect(fill.westMeshes).toEqual([west.data.mesh]);
        expect(fill.southTiles).toEqual([south]);
        expect(fill.southMeshes).toEqual([south.data.mesh]);
        expect(fill.eastTiles).toEqual([east]);
        expect(fill.eastMeshes).toEqual([east.data.mesh]);
        expect(fill.northTiles).toEqual([north]);
        expect(fill.northMeshes).toEqual([north.data.mesh]);
        expect(fill.southwestTile).toEqual(southwest);
        expect(fill.southwestMesh).toEqual(southwest.data.mesh);
        expect(fill.southeastTile).toEqual(southeast);
        expect(fill.southeastMesh).toEqual(southeast.data.mesh);
        expect(fill.northwestTile).toEqual(northwest);
        expect(fill.northwestMesh).toEqual(northwest.data.mesh);
        expect(fill.northeastTile).toEqual(northeast);
        expect(fill.northeastMesh).toEqual(northeast.data.mesh);
      });
    });

    it("propagates fill tile edges to an unloaded tile", function () {
      var centerSW = center.southwestChild;
      var centerSE = center.southeastChild;
      var centerNW = center.northwestChild;
      var centerNE = center.northeastChild;

      var tiles = [
        centerSW,
        centerSE,
        centerNW,
        centerNE,
        west,
        south,
        east,
        north,
        southwest,
        southeast,
        northwest,
        northeast,
      ];

      tiles.forEach(mockTerrain.createMeshWillSucceed.bind(mockTerrain));

      return processor.process(tiles).then(function () {
        tiles.forEach(markRendered);

        TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);

        var sw = centerSW.data.fill;
        var se = centerSE.data.fill;
        var nw = centerNW.data.fill;
        var ne = centerNE.data.fill;

        expect(sw).toBeDefined();
        expect(sw.westTiles).toEqual([west]);
        expect(sw.westMeshes).toEqual([west.data.mesh]);
        expect(sw.southTiles).toEqual([south]);
        expect(sw.southMeshes).toEqual([south.data.mesh]);
        expect(sw.southwestTile).toEqual(southwest);
        expect(sw.southwestMesh).toEqual(southwest.data.mesh);
        expect(sw.southeastTile).toBeUndefined();
        expect(sw.southeastMesh).toBeUndefined();
        expect(sw.northwestTile).toBeUndefined();
        expect(sw.northwestMesh).toBeUndefined();

        expect(se).toBeDefined();
        expect(se.eastTiles).toEqual([east]);
        expect(se.eastMeshes).toEqual([east.data.mesh]);
        expect(se.southTiles).toEqual([south]);
        expect(se.southMeshes).toEqual([south.data.mesh]);
        expect(se.southeastTile).toEqual(southeast);
        expect(se.southeastMesh).toEqual(southeast.data.mesh);
        expect(se.southwestTile).toBeUndefined();
        expect(se.southwestMesh).toBeUndefined();
        expect(se.northeastTile).toBeUndefined();
        expect(se.northeastMesh).toBeUndefined();

        expect(nw).toBeDefined();
        expect(nw.westTiles).toEqual([west]);
        expect(nw.westMeshes).toEqual([west.data.mesh]);
        expect(nw.northTiles).toEqual([north]);
        expect(nw.northMeshes).toEqual([north.data.mesh]);
        expect(nw.northwestTile).toEqual(northwest);
        expect(nw.northwestMesh).toEqual(northwest.data.mesh);
        expect(nw.southwestTile).toBeUndefined();
        expect(nw.southwestMesh).toBeUndefined();
        expect(nw.northeastTile).toBeUndefined();
        expect(nw.northeastMesh).toBeUndefined();

        expect(ne).toBeDefined();
        expect(ne.eastTiles).toEqual([east]);
        expect(ne.eastMeshes).toEqual([east.data.mesh]);
        expect(ne.northTiles).toEqual([north]);
        expect(ne.northMeshes).toEqual([north.data.mesh]);
        expect(ne.northeastTile).toEqual(northeast);
        expect(ne.northeastMesh).toEqual(northeast.data.mesh);
        expect(ne.southeastTile).toBeUndefined();
        expect(ne.southeastMesh).toBeUndefined();
        expect(ne.northwestTile).toBeUndefined();
        expect(ne.northwestMesh).toBeUndefined();

        expect(
          sw.eastTiles[0] === centerSE || se.westTiles[0] === centerSW
        ).toBe(true);
        expect(
          nw.eastTiles[0] === centerNE || ne.westTiles[0] === centerNW
        ).toBe(true);

        expect(
          sw.northTiles[0] === centerNW || nw.southTiles[0] === centerSW
        ).toBe(true);
        expect(
          se.northTiles[0] === centerNE || ne.southTiles[0] === centerSE
        ).toBe(true);

        expect(
          sw.northeastTile === centerNE || ne.southwestTile === centerSW
        ).toBe(true);
        expect(
          nw.southeastTile === centerSE || se.northwestTile === centerNW
        ).toBe(true);
      });
    });

    it("does not touch disconnected tiles", function () {
      var disconnected = center.southwestChild.northeastChild;

      var tiles = [
        disconnected,
        west,
        south,
        east,
        north,
        southwest,
        southeast,
        northwest,
        northeast,
      ];

      tiles.forEach(mockTerrain.createMeshWillSucceed.bind(mockTerrain));

      return processor.process(tiles).then(function () {
        tiles.forEach(markRendered);

        TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);

        expect(disconnected.data.fill).toBeUndefined();
      });
    });

    it("propagates multiple adjacent source tiles to a destination edge", function () {
      var tiles = [center, west, south, east, north];
      [west, south, east, north].forEach(function (tile) {
        tile.children.forEach(function (child) {
          mockTerrain.willBeUnavailable(child);
          mockTerrain.upsampleWillSucceed(child);
          tiles.push(child);
        });
      });

      return processor.process(tiles).then(function () {
        tiles.forEach(markRendered);

        TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);

        var fill = center.data.fill;
        expect(fill).toBeDefined();
        expect(fill.westTiles).toEqual([
          west.northeastChild,
          west.southeastChild,
        ]);
        expect(fill.southTiles).toEqual([
          south.northwestChild,
          south.northeastChild,
        ]);
        expect(fill.eastTiles).toEqual([
          east.southwestChild,
          east.northwestChild,
        ]);
        expect(fill.northTiles).toEqual([
          north.southeastChild,
          north.southwestChild,
        ]);
      });
    });

    it("adjusts existing fill tiles when adjacent tiles are loaded", function () {
      var tiles = [center, west, south, north];

      tiles.forEach(mockTerrain.createMeshWillSucceed.bind(mockTerrain));

      return processor
        .process(tiles)
        .then(function () {
          tiles.forEach(markRendered);

          TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);

          var fill = center.data.fill;
          expect(fill).toBeDefined();
          expect(fill.westTiles).toEqual([west]);
          expect(fill.westMeshes).toEqual([west.data.mesh]);
          expect(fill.southTiles).toEqual([south]);
          expect(fill.southMeshes).toEqual([south.data.mesh]);
          expect(fill.eastTiles).toEqual([]);
          expect(fill.eastMeshes).toEqual([]);
          expect(fill.northTiles).toEqual([north]);
          expect(fill.northMeshes).toEqual([north.data.mesh]);

          fill.update(tileProvider, frameState);

          expectVertexCount(fill, 8);

          tiles.push(east);

          return processor.process(tiles);
        })
        .then(function () {
          tiles.forEach(markRendered);

          TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);

          var fill = center.data.fill;
          expect(fill).toBeDefined();
          expect(fill.westTiles).toEqual([west]);
          expect(fill.westMeshes).toEqual([west.data.mesh]);
          expect(fill.southTiles).toEqual([south]);
          expect(fill.southMeshes).toEqual([south.data.mesh]);
          expect(fill.eastTiles).toEqual([east]);
          expect(fill.eastMeshes).toEqual([east.data.mesh]);
          expect(fill.northTiles).toEqual([north]);
          expect(fill.northMeshes).toEqual([north.data.mesh]);

          fill.update(tileProvider, frameState);

          expectVertexCount(fill, 9);
          expectVertex(fill, 1.0, 0.5, 26.0);
        });
    });

    it("adjusts existing fill tiles when an adjacent fill tile changes", function () {
      var dontLoad = [east, south, southeast];
      dontLoad.forEach(
        mockTerrain.requestTileGeometryWillDefer.bind(mockTerrain)
      );

      var tiles = [
        center,
        west,
        south,
        east,
        north,
        southwest,
        southeast,
        northwest,
        northeast,
      ];

      return processor
        .process(tiles)
        .then(function () {
          tiles.forEach(markRendered);

          TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);
          center.data.fill.update(tileProvider, frameState);
          south.data.fill.update(tileProvider, frameState);
          east.data.fill.update(tileProvider, frameState);
          southeast.data.fill.update(tileProvider, frameState);

          expectVertexCount(center.data.fill, 7);
          expectVertex(center.data.fill, 0.0, 0.0, 31.0);
          expectVertex(center.data.fill, 0.0, 0.5, 24.0);
          expectVertex(center.data.fill, 0.0, 1.0, 17.0);
          expectVertex(center.data.fill, 0.5, 1.0, 18.0);
          expectVertex(center.data.fill, 1.0, 1.0, 19.0);

          expectVertexCount(south.data.fill, 6);
          expectVertex(south.data.fill, 0.0, 1.0, 31.0);
          expectVertex(south.data.fill, 0.0, 0.5, 38.0);
          expectVertex(south.data.fill, 0.0, 0.0, 45.0);

          expectVertexCount(east.data.fill, 6);
          expectVertex(east.data.fill, 0.0, 1.0, 19.0);
          expectVertex(east.data.fill, 0.5, 1.0, 20.0);
          expectVertex(east.data.fill, 1.0, 1.0, 21.0);

          expectVertexCount(southeast.data.fill, 5);

          expect(getHeight(center.data.fill, 1.0, 0.0)).toBe(
            getHeight(southeast.data.fill, 0.0, 1.0)
          );
          expect(getHeight(center.data.fill, 1.0, 0.0)).toBe(
            getHeight(south.data.fill, 1.0, 1.0)
          );
          expect(getHeight(center.data.fill, 1.0, 0.0)).toBe(
            getHeight(east.data.fill, 0.0, 0.0)
          );
          expect(getHeight(center.data.fill, 1.0, 1.0)).toBe(
            getHeight(east.data.fill, 0.0, 1.0)
          );
          expect(getHeight(east.data.fill, 1.0, 0.0)).toBe(
            getHeight(southeast.data.fill, 1.0, 1.0)
          );
          expect(getHeight(south.data.fill, 1.0, 0.0)).toBe(
            getHeight(southeast.data.fill, 0.0, 0.0)
          );

          // Now load the south tile.
          mockTerrain
            .requestTileGeometryWillSucceedWith(
              new HeightmapTerrainData({
                width: 3,
                height: 3,
                createdByUpsampling: false,
                buffer: new Float32Array([
                  31.0,
                  32.0,
                  33.0,
                  38.0,
                  39.0,
                  40.0,
                  45.0,
                  46.0,
                  47.0,
                ]),
              }),
              south
            )
            .createMeshWillSucceed(south);

          return processor.process(tiles);
        })
        .then(function () {
          tiles.forEach(markRendered);

          TerrainFillMesh.updateFillTiles(tileProvider, tiles, frameState);
          center.data.fill.update(tileProvider, frameState);
          east.data.fill.update(tileProvider, frameState);
          southeast.data.fill.update(tileProvider, frameState);

          expect(south.data.fill).toBeUndefined();

          expectVertexCount(center.data.fill, 8);
          expectVertex(center.data.fill, 0.0, 0.0, 31.0);
          expectVertex(center.data.fill, 0.0, 0.5, 24.0);
          expectVertex(center.data.fill, 0.0, 1.0, 17.0);
          expectVertex(center.data.fill, 0.5, 1.0, 18.0);
          expectVertex(center.data.fill, 1.0, 1.0, 19.0);
          expectVertex(center.data.fill, 1.0, 0.0, 33.0);

          expectVertexCount(east.data.fill, 6);
          expectVertex(east.data.fill, 0.0, 1.0, 19.0);
          expectVertex(east.data.fill, 0.5, 1.0, 20.0);
          expectVertex(east.data.fill, 1.0, 1.0, 21.0);
          expectVertex(east.data.fill, 0.0, 0.0, 33.0);

          expectVertexCount(southeast.data.fill, 6);
          expectVertex(southeast.data.fill, 0.0, 0.0, 47.0);
          expectVertex(southeast.data.fill, 0.0, 0.5, 40.0);
          expectVertex(southeast.data.fill, 0.0, 1.0, 33.0);

          expect(getHeight(east.data.fill, 1.0, 0.0)).toBe(
            getHeight(southeast.data.fill, 1.0, 1.0)
          );
        });
    });

    // Mark all the tiles rendered.
    function markRendered(tile) {
      quadtree._lastSelectionFrameNumber = frameState.frameNumber;
      tile._lastSelectionResultFrame = frameState.frameNumber;
      tile._lastSelectionResult = TileSelectionResult.RENDERED;

      var parent = tile.parent;
      while (parent) {
        if (parent._lastSelectionResultFrame !== frameState.frameNumber) {
          parent._lastSelectionResultFrame = frameState.frameNumber;
          parent._lastSelectionResult = TileSelectionResult.REFINED;
        }
        parent = parent.parent;
      }
    }
  });

  describe("update", function () {
    it("puts a middle height at the four corners and center when there are no adjacent tiles", function () {
      return processor.process([center]).then(function () {
        center.data.tileBoundingRegion = new TileBoundingRegion({
          rectangle: center.rectangle,
          minimumHeight: 1.0,
          maximumHeight: 3.0,
          computeBoundingVolumes: false,
        });

        var fill = (center.data.fill = new TerrainFillMesh(center));
        fill.update(tileProvider, frameState);

        expectVertexCount(fill, 5);
        expectVertex(fill, 0.0, 0.0, 2.0);
        expectVertex(fill, 0.0, 1.0, 2.0);
        expectVertex(fill, 1.0, 0.0, 2.0);
        expectVertex(fill, 1.0, 1.0, 2.0);
        expectVertex(fill, 0.5, 0.5, 2.0);
      });
    });

    it("puts zero height at the four corners and center when there are no adjacent tiles and no bounding region", function () {
      return processor.process([center]).then(function () {
        var fill = (center.data.fill = new TerrainFillMesh(center));
        fill.update(tileProvider, frameState);

        expectVertexCount(fill, 5);
        expectVertex(fill, 0.0, 0.0, 0.0);
        expectVertex(fill, 0.0, 1.0, 0.0);
        expectVertex(fill, 1.0, 0.0, 0.0);
        expectVertex(fill, 1.0, 1.0, 0.0);
        expectVertex(fill, 0.5, 0.5, 0.0);
      });
    });

    it("uses adjacent edge heights", function () {
      return processor
        .process([center, west, south, east, north])
        .then(function () {
          var fill = (center.data.fill = new TerrainFillMesh(center));

          fill.westTiles.push(west);
          fill.westMeshes.push(west.data.mesh);
          fill.southTiles.push(south);
          fill.southMeshes.push(south.data.mesh);
          fill.eastTiles.push(east);
          fill.eastMeshes.push(east.data.mesh);
          fill.northTiles.push(north);
          fill.northMeshes.push(north.data.mesh);

          fill.update(tileProvider, frameState);

          expectVertexCount(fill, 9);
          expectVertex(fill, 0.0, 0.0, 31.0);
          expectVertex(fill, 0.5, 0.0, 32.0);
          expectVertex(fill, 1.0, 0.0, 33.0);
          expectVertex(fill, 0.0, 0.5, 24.0);
          expectVertex(fill, 0.5, 0.5, (33.0 + 17.0) / 2);
          expectVertex(fill, 1.0, 0.5, 26.0);
          expectVertex(fill, 0.0, 1.0, 17.0);
          expectVertex(fill, 0.5, 1.0, 18.0);
          expectVertex(fill, 1.0, 1.0, 19.0);
        });
    });

    it("uses adjacent corner heights if adjacent edges are not available", function () {
      return processor
        .process([center, southwest, southeast, northwest, northeast])
        .then(function () {
          var fill = (center.data.fill = new TerrainFillMesh(center));

          fill.southwestTile = southwest;
          fill.southwestMesh = southwest.data.mesh;
          fill.southeastTile = southeast;
          fill.southeastMesh = southeast.data.mesh;
          fill.northwestTile = northwest;
          fill.northwestMesh = northwest.data.mesh;
          fill.northeastTile = northeast;
          fill.northeastMesh = northeast.data.mesh;

          fill.update(tileProvider, frameState);

          expectVertexCount(fill, 5);
          expectVertex(fill, 0.0, 0.0, 31.0);
          expectVertex(fill, 1.0, 0.0, 33.0);
          expectVertex(fill, 0.0, 1.0, 17.0);
          expectVertex(fill, 1.0, 1.0, 19.0);
          expectVertex(fill, 0.5, 0.5, (17.0 + 33.0) / 2.0);
        });
    });

    it("finds a suitable corner vertex in a less detailed tile", function () {
      var sw = center.southwestChild;
      var se = center.southeastChild;
      var nw = center.northwestChild;
      var ne = center.northeastChild;

      return processor
        .process([sw, se, nw, ne, west, south, east, north])
        .then(function () {
          var fillSW = (sw.data.fill = new TerrainFillMesh(sw));
          var fillSE = (se.data.fill = new TerrainFillMesh(se));
          var fillNW = (nw.data.fill = new TerrainFillMesh(nw));
          var fillNE = (ne.data.fill = new TerrainFillMesh(ne));

          fillSW.westTiles.push(west);
          fillSW.westMeshes.push(west.data.mesh);
          fillSW.southTiles.push(south);
          fillSW.southMeshes.push(south.data.mesh);

          fillSE.eastTiles.push(east);
          fillSE.eastMeshes.push(east.data.mesh);
          fillSE.southTiles.push(south);
          fillSE.southMeshes.push(south.data.mesh);

          fillNW.westTiles.push(west);
          fillNW.westMeshes.push(west.data.mesh);
          fillNW.northTiles.push(north);
          fillNW.northMeshes.push(north.data.mesh);

          fillNE.eastTiles.push(east);
          fillNE.eastMeshes.push(east.data.mesh);
          fillNE.northTiles.push(north);
          fillNE.northMeshes.push(north.data.mesh);

          fillSW.update(tileProvider, frameState);
          fillSE.update(tileProvider, frameState);
          fillNW.update(tileProvider, frameState);
          fillNE.update(tileProvider, frameState);

          expectVertexCount(fillSW, 5);
          expectVertex(fillSW, 0.0, 0.0, 31.0);
          expectVertex(fillSW, 1.0, 0.0, 32.0);
          expectVertex(fillSW, 0.0, 1.0, 24.0);
          expectVertex(fillSW, 1.0, 1.0, (24.0 + 32.0) / 2);
          expectVertex(fillSW, 0.5, 0.5, (24.0 + 32.0) / 2);

          expectVertexCount(fillSE, 5);
          expectVertex(fillSE, 0.0, 0.0, 32.0);
          expectVertex(fillSE, 1.0, 0.0, 33.0);
          expectVertex(fillSE, 0.0, 1.0, (32.0 + 26.0) / 2);
          expectVertex(fillSE, 1.0, 1.0, 26.0);
          expectVertex(fillSE, 0.5, 0.5, (26.0 + 33.0) / 2);

          expectVertexCount(fillNW, 5);
          expectVertex(fillNW, 0.0, 0.0, 24.0);
          expectVertex(fillNW, 1.0, 0.0, (18.0 + 24.0) / 2);
          expectVertex(fillNW, 0.0, 1.0, 17.0);
          expectVertex(fillNW, 1.0, 1.0, 18.0);
          expectVertex(fillNW, 0.5, 0.5, (17.0 + 24.0) / 2);

          expectVertexCount(fillNE, 5);
          expectVertex(fillNE, 0.0, 0.0, (18.0 + 26.0) / 2);
          expectVertex(fillNE, 1.0, 0.0, 26.0);
          expectVertex(fillNE, 0.0, 1.0, 18.0);
          expectVertex(fillNE, 1.0, 1.0, 19.0);
          expectVertex(fillNE, 0.5, 0.5, (18.0 + 26.0) / 2);
        });
    });

    it("interpolates a suitable corner vertex from a less detailed tile", function () {
      var sw = center.southwestChild.southwestChild;
      var se = center.southeastChild.southeastChild;
      var nw = center.northwestChild.northwestChild;
      var ne = center.northeastChild.northeastChild;

      return processor
        .process([sw, se, nw, ne, west, south, east, north])
        .then(function () {
          var fillSW = (sw.data.fill = new TerrainFillMesh(sw));
          var fillSE = (se.data.fill = new TerrainFillMesh(se));
          var fillNW = (nw.data.fill = new TerrainFillMesh(nw));
          var fillNE = (ne.data.fill = new TerrainFillMesh(ne));

          fillSW.westTiles.push(west);
          fillSW.westMeshes.push(west.data.mesh);
          fillSW.southTiles.push(south);
          fillSW.southMeshes.push(south.data.mesh);

          fillSE.eastTiles.push(east);
          fillSE.eastMeshes.push(east.data.mesh);
          fillSE.southTiles.push(south);
          fillSE.southMeshes.push(south.data.mesh);

          fillNW.westTiles.push(west);
          fillNW.westMeshes.push(west.data.mesh);
          fillNW.northTiles.push(north);
          fillNW.northMeshes.push(north.data.mesh);

          fillNE.eastTiles.push(east);
          fillNE.eastMeshes.push(east.data.mesh);
          fillNE.northTiles.push(north);
          fillNE.northMeshes.push(north.data.mesh);

          fillSW.update(tileProvider, frameState);
          fillSE.update(tileProvider, frameState);
          fillNW.update(tileProvider, frameState);
          fillNE.update(tileProvider, frameState);

          expectVertexCount(fillSW, 5);
          expectVertex(fillSW, 0.0, 0.0, 31.0);
          expectVertex(fillSW, 1.0, 0.0, (31.0 + 32.0) / 2);
          expectVertex(fillSW, 0.0, 1.0, (31.0 + 24.0) / 2);
          expectVertex(
            fillSW,
            1.0,
            1.0,
            ((31.0 + 32.0) / 2 + (31.0 + 24.0) / 2) / 2
          );
          expectVertex(
            fillSW,
            0.5,
            0.5,
            ((31.0 + 32.0) / 2 + (31.0 + 24.0) / 2) / 2
          );

          expectVertexCount(fillSE, 5);
          expectVertex(fillSE, 0.0, 0.0, (32.0 + 33.0) / 2);
          expectVertex(fillSE, 1.0, 0.0, 33.0);
          expectVertex(
            fillSE,
            0.0,
            1.0,
            ((32.0 + 33.0) / 2 + (33.0 + 26.0) / 2) / 2
          );
          expectVertex(fillSE, 1.0, 1.0, (33.0 + 26.0) / 2);
          expectVertex(fillSE, 0.5, 0.5, (33.0 + (33.0 + 26.0) / 2) / 2);

          expectVertexCount(fillNW, 5);
          expectVertex(fillNW, 0.0, 0.0, (17.0 + 24.0) / 2);
          expectVertex(
            fillNW,
            1.0,
            0.0,
            ((17.0 + 18.0) / 2 + (17.0 + 24.0) / 2) / 2
          );
          expectVertex(fillNW, 0.0, 1.0, 17.0);
          expectVertex(fillNW, 1.0, 1.0, (17.0 + 18.0) / 2);
          expectVertex(fillNW, 0.5, 0.5, (17.0 + (17.0 + 24.0) / 2) / 2);

          expectVertexCount(fillNE, 5);
          expectVertex(
            fillNE,
            0.0,
            0.0,
            ((19.0 + 26.0) / 2 + (18.0 + 19.0) / 2) / 2
          );
          expectVertex(fillNE, 1.0, 0.0, (19.0 + 26.0) / 2);
          expectVertex(fillNE, 0.0, 1.0, (18.0 + 19.0) / 2);
          expectVertex(fillNE, 1.0, 1.0, 19.0);
          expectVertex(
            fillNE,
            0.5,
            0.5,
            ((18.0 + 19.0) / 2 + (19.0 + 26.0) / 2) / 2
          );
        });
    });

    it("uses the height of the closest vertex when an edge does not include the corner", function () {
      var westN = west.northeastChild.southeastChild;
      var westS = west.southeastChild.northeastChild;
      var eastN = east.northwestChild.southwestChild;
      var eastS = east.southwestChild.northwestChild;
      var northW = north.southwestChild.southeastChild;
      var northE = north.southeastChild.southwestChild;
      var southW = south.northwestChild.northeastChild;
      var southE = south.northeastChild.northwestChild;

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([1.0, 1.0, 1.5, 1.5]),
          }),
          westN
        )
        .createMeshWillSucceed(westN);

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([1.5, 1.5, 2.0, 2.0]),
          }),
          westS
        )
        .createMeshWillSucceed(westS);

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([3.0, 3.0, 3.5, 3.5]),
          }),
          eastN
        )
        .createMeshWillSucceed(eastN);

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([3.5, 3.5, 4.0, 4.0]),
          }),
          eastS
        )
        .createMeshWillSucceed(eastS);

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([5.0, 5.5, 5.0, 5.5]),
          }),
          northW
        )
        .createMeshWillSucceed(northW);

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([5.5, 6.0, 6.5, 6.0]),
          }),
          northE
        )
        .createMeshWillSucceed(northE);

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([7.0, 7.5, 7.0, 7.5]),
          }),
          southW
        )
        .createMeshWillSucceed(southW);

      mockTerrain
        .requestTileGeometryWillSucceedWith(
          new HeightmapTerrainData({
            width: 2,
            height: 2,
            createdByUpsampling: false,
            buffer: new Float32Array([7.5, 8.0, 7.5, 8.0]),
          }),
          southE
        )
        .createMeshWillSucceed(southE);

      return processor
        .process([
          center,
          westN,
          westS,
          eastN,
          eastS,
          northE,
          northW,
          southE,
          southW,
        ])
        .then(function () {
          var fill = (center.data.fill = new TerrainFillMesh(center));

          fill.westTiles.push(westN, westS);
          fill.westMeshes.push(westN.data.mesh, westS.data.mesh);
          fill.eastTiles.push(eastS, eastN);
          fill.eastMeshes.push(eastS.data.mesh, eastN.data.mesh);
          fill.northTiles.push(northE, northW);
          fill.northMeshes.push(northE.data.mesh, northW.data.mesh);
          fill.southTiles.push(southW, southE);
          fill.southMeshes.push(southW.data.mesh, southE.data.mesh);

          fill.update(tileProvider, frameState);

          expectVertexCount(fill, 17);
          expectVertex(fill, 0.0, 0.0, (2.0 + 7.0) / 2);
          expectVertex(fill, 0.0, 0.25, 2.0);
          expectVertex(fill, 0.0, 0.5, 1.5);
          expectVertex(fill, 0.0, 0.75, 1.0);
          expectVertex(fill, 0.0, 1.0, (1.0 + 5.0) / 2);
          expectVertex(fill, 1.0, 0.0, (4.0 + 8.0) / 2);
          expectVertex(fill, 1.0, 0.25, 4.0);
          expectVertex(fill, 1.0, 0.5, 3.5);
          expectVertex(fill, 1.0, 0.75, 3.0);
          expectVertex(fill, 1.0, 1.0, (3.0 + 6.0) / 2);
        });
    });

    describe("correctly transforms texture coordinates across the anti-meridian", function () {
      var westernHemisphere;
      var easternHemisphere;

      beforeEach(function () {
        westernHemisphere =
          rootTiles[0].southwestChild.northwestChild.southwestChild
            .northwestChild;
        easternHemisphere =
          rootTiles[1].southeastChild.northeastChild.southeastChild
            .northeastChild;

        // Make sure we have a standard geographic tiling scheme with two root tiles,
        // the first covering the western hemisphere and the second the eastern.
        expect(rootTiles.length).toBe(2);
        expect(westernHemisphere.x).toBe(0);
        expect(easternHemisphere.x).toBe(31);
      });

      it("western hemisphere to eastern hemisphere", function () {
        mockTerrain.requestTileGeometryWillDefer(easternHemisphere);
        mockTerrain
          .requestTileGeometryWillSucceedWith(
            new HeightmapTerrainData({
              width: 3,
              height: 3,
              createdByUpsampling: false,
              buffer: new Float32Array([
                1.0,
                2.0,
                3.0,
                4.0,
                5.0,
                6.0,
                7.0,
                8.0,
                9.0,
              ]),
            }),
            westernHemisphere
          )
          .createMeshWillSucceed(westernHemisphere);

        return processor
          .process([westernHemisphere, easternHemisphere])
          .then(function () {
            var fill = (easternHemisphere.data.fill = new TerrainFillMesh(
              easternHemisphere
            ));

            fill.eastTiles.push(westernHemisphere);
            fill.eastMeshes.push(westernHemisphere.data.mesh);

            fill.update(tileProvider, frameState);

            expectVertexCount(fill, 6);
            expectVertex(fill, 1.0, 0.0, 7.0);
            expectVertex(fill, 1.0, 0.5, 4.0);
            expectVertex(fill, 1.0, 1.0, 1.0);
          });
      });

      it("eastern hemisphere to western hemisphere", function () {
        mockTerrain
          .requestTileGeometryWillSucceedWith(
            new HeightmapTerrainData({
              width: 3,
              height: 3,
              createdByUpsampling: false,
              buffer: new Float32Array([
                10.0,
                11.0,
                12.0,
                13.0,
                14.0,
                15.0,
                16.0,
                17.0,
                18.0,
              ]),
            }),
            easternHemisphere
          )
          .createMeshWillSucceed(easternHemisphere);
        mockTerrain.requestTileGeometryWillDefer(westernHemisphere);

        return processor
          .process([westernHemisphere, easternHemisphere])
          .then(function () {
            var fill = (westernHemisphere.data.fill = new TerrainFillMesh(
              westernHemisphere
            ));

            fill.westTiles.push(easternHemisphere);
            fill.westMeshes.push(easternHemisphere.data.mesh);

            fill.update(tileProvider, frameState);

            expectVertexCount(fill, 6);
            expectVertex(fill, 0.0, 0.0, 18.0);
            expectVertex(fill, 0.0, 0.5, 15.0);
            expectVertex(fill, 0.0, 1.0, 12.0);
          });
      });
    });
  });

  var textureCoordinateScratch = new Cartesian2();
  var positionScratch = new Cartesian3();
  var expectedPositionScratch = new Cartesian3();

  function getHeight(fill, u, v) {
    var mesh = fill.mesh;
    var rectangle = fill.tile.rectangle;
    var encoding = mesh.encoding;
    var vertices = mesh.vertices;
    var stride = encoding.getStride();
    var count = mesh.vertices.length / stride;

    for (var i = 0; i < count; ++i) {
      var tc = encoding.decodeTextureCoordinates(
        vertices,
        i,
        textureCoordinateScratch
      );
      var vertexHeight = encoding.decodeHeight(vertices, i);
      var vertexPosition = encoding.decodePosition(
        vertices,
        i,
        positionScratch
      );
      if (
        Math.abs(u - tc.x) < 1e-5 &&
        Math.abs(v - tc.y) < CesiumMath.EPSILON5
      ) {
        var longitude = CesiumMath.lerp(rectangle.west, rectangle.east, u);
        var latitude = CesiumMath.lerp(rectangle.south, rectangle.north, v);
        var expectedPosition = Cartesian3.fromRadians(
          longitude,
          latitude,
          vertexHeight,
          undefined,
          expectedPositionScratch
        );
        expect(vertexPosition).toEqualEpsilon(expectedPosition, 1);
        return vertexHeight;
      }
    }

    fail("Vertex with u=" + u + ", v=" + v + " does not exist.");
  }

  function expectVertex(fill, u, v, height) {
    var vertexHeight = getHeight(fill, u, v);
    expect(vertexHeight).toEqualEpsilon(height, CesiumMath.EPSILON5);
  }

  function expectVertexCount(fill, count) {
    expect(fill.mesh.vertices.length).toBe(
      count * fill.mesh.encoding.getStride()
    );
  }
});