Cesium-Prequel/Source/Workers/createVectorTilePolylines.js

/* This file is automatically rebuilt by the Cesium build process. */
define(['./Cartesian2-44e93af5', './AttributeCompression-e3a6496c', './Math-8c161f1c', './IndexDatatype-e20e62f1', './createTaskProcessorWorker', './Check-285f6bfc', './when-f31b6bd1', './WebGLConstants-34c08bc0'], function (Cartesian2, AttributeCompression, _Math, IndexDatatype, createTaskProcessorWorker, Check, when, WebGLConstants) { 'use strict';

  var maxShort = 32767;

  var scratchBVCartographic = new Cartesian2.Cartographic();
  var scratchEncodedPosition = new Cartesian2.Cartesian3();

  function decodeVectorPolylinePositions(
    positions,
    rectangle,
    minimumHeight,
    maximumHeight,
    ellipsoid
  ) {
    var positionsLength = positions.length / 3;
    var uBuffer = positions.subarray(0, positionsLength);
    var vBuffer = positions.subarray(positionsLength, 2 * positionsLength);
    var heightBuffer = positions.subarray(
      2 * positionsLength,
      3 * positionsLength
    );
    AttributeCompression.AttributeCompression.zigZagDeltaDecode(uBuffer, vBuffer, heightBuffer);

    var decoded = new Float64Array(positions.length);
    for (var i = 0; i < positionsLength; ++i) {
      var u = uBuffer[i];
      var v = vBuffer[i];
      var h = heightBuffer[i];

      var lon = _Math.CesiumMath.lerp(rectangle.west, rectangle.east, u / maxShort);
      var lat = _Math.CesiumMath.lerp(rectangle.south, rectangle.north, v / maxShort);
      var alt = _Math.CesiumMath.lerp(minimumHeight, maximumHeight, h / maxShort);

      var cartographic = Cartesian2.Cartographic.fromRadians(
        lon,
        lat,
        alt,
        scratchBVCartographic
      );
      var decodedPosition = ellipsoid.cartographicToCartesian(
        cartographic,
        scratchEncodedPosition
      );
      Cartesian2.Cartesian3.pack(decodedPosition, decoded, i * 3);
    }
    return decoded;
  }

  var scratchRectangle = new Cartesian2.Rectangle();
  var scratchEllipsoid = new Cartesian2.Ellipsoid();
  var scratchCenter = new Cartesian2.Cartesian3();
  var scratchMinMaxHeights = {
    min: undefined,
    max: undefined,
  };

  function unpackBuffer(packedBuffer) {
    packedBuffer = new Float64Array(packedBuffer);

    var offset = 0;
    scratchMinMaxHeights.min = packedBuffer[offset++];
    scratchMinMaxHeights.max = packedBuffer[offset++];

    Cartesian2.Rectangle.unpack(packedBuffer, offset, scratchRectangle);
    offset += Cartesian2.Rectangle.packedLength;

    Cartesian2.Ellipsoid.unpack(packedBuffer, offset, scratchEllipsoid);
    offset += Cartesian2.Ellipsoid.packedLength;

    Cartesian2.Cartesian3.unpack(packedBuffer, offset, scratchCenter);
  }

  var scratchP0 = new Cartesian2.Cartesian3();
  var scratchP1 = new Cartesian2.Cartesian3();
  var scratchPrev = new Cartesian2.Cartesian3();
  var scratchCur = new Cartesian2.Cartesian3();
  var scratchNext = new Cartesian2.Cartesian3();

  function createVectorTilePolylines(parameters, transferableObjects) {
    var encodedPositions = new Uint16Array(parameters.positions);
    var widths = new Uint16Array(parameters.widths);
    var counts = new Uint32Array(parameters.counts);
    var batchIds = new Uint16Array(parameters.batchIds);

    unpackBuffer(parameters.packedBuffer);
    var rectangle = scratchRectangle;
    var ellipsoid = scratchEllipsoid;
    var center = scratchCenter;
    var minimumHeight = scratchMinMaxHeights.min;
    var maximumHeight = scratchMinMaxHeights.max;

    var positions = decodeVectorPolylinePositions(
      encodedPositions,
      rectangle,
      minimumHeight,
      maximumHeight,
      ellipsoid
    );

    var positionsLength = positions.length / 3;
    var size = positionsLength * 4 - 4;

    var curPositions = new Float32Array(size * 3);
    var prevPositions = new Float32Array(size * 3);
    var nextPositions = new Float32Array(size * 3);
    var expandAndWidth = new Float32Array(size * 2);
    var vertexBatchIds = new Uint16Array(size);

    var positionIndex = 0;
    var expandAndWidthIndex = 0;
    var batchIdIndex = 0;

    var i;
    var offset = 0;
    var length = counts.length;

    for (i = 0; i < length; ++i) {
      var count = counts[i];
      var width = widths[i];
      var batchId = batchIds[i];

      for (var j = 0; j < count; ++j) {
        var previous;
        if (j === 0) {
          var p0 = Cartesian2.Cartesian3.unpack(positions, offset * 3, scratchP0);
          var p1 = Cartesian2.Cartesian3.unpack(positions, (offset + 1) * 3, scratchP1);

          previous = Cartesian2.Cartesian3.subtract(p0, p1, scratchPrev);
          Cartesian2.Cartesian3.add(p0, previous, previous);
        } else {
          previous = Cartesian2.Cartesian3.unpack(
            positions,
            (offset + j - 1) * 3,
            scratchPrev
          );
        }

        var current = Cartesian2.Cartesian3.unpack(positions, (offset + j) * 3, scratchCur);

        var next;
        if (j === count - 1) {
          var p2 = Cartesian2.Cartesian3.unpack(
            positions,
            (offset + count - 1) * 3,
            scratchP0
          );
          var p3 = Cartesian2.Cartesian3.unpack(
            positions,
            (offset + count - 2) * 3,
            scratchP1
          );

          next = Cartesian2.Cartesian3.subtract(p2, p3, scratchNext);
          Cartesian2.Cartesian3.add(p2, next, next);
        } else {
          next = Cartesian2.Cartesian3.unpack(positions, (offset + j + 1) * 3, scratchNext);
        }

        Cartesian2.Cartesian3.subtract(previous, center, previous);
        Cartesian2.Cartesian3.subtract(current, center, current);
        Cartesian2.Cartesian3.subtract(next, center, next);

        var startK = j === 0 ? 2 : 0;
        var endK = j === count - 1 ? 2 : 4;

        for (var k = startK; k < endK; ++k) {
          Cartesian2.Cartesian3.pack(current, curPositions, positionIndex);
          Cartesian2.Cartesian3.pack(previous, prevPositions, positionIndex);
          Cartesian2.Cartesian3.pack(next, nextPositions, positionIndex);
          positionIndex += 3;

          var direction = k - 2 < 0 ? -1.0 : 1.0;
          expandAndWidth[expandAndWidthIndex++] = 2 * (k % 2) - 1;
          expandAndWidth[expandAndWidthIndex++] = direction * width;

          vertexBatchIds[batchIdIndex++] = batchId;
        }
      }

      offset += count;
    }

    var indices = IndexDatatype.IndexDatatype.createTypedArray(size, positionsLength * 6 - 6);
    var index = 0;
    var indicesIndex = 0;
    length = positionsLength - 1;
    for (i = 0; i < length; ++i) {
      indices[indicesIndex++] = index;
      indices[indicesIndex++] = index + 2;
      indices[indicesIndex++] = index + 1;

      indices[indicesIndex++] = index + 1;
      indices[indicesIndex++] = index + 2;
      indices[indicesIndex++] = index + 3;

      index += 4;
    }

    transferableObjects.push(
      curPositions.buffer,
      prevPositions.buffer,
      nextPositions.buffer
    );
    transferableObjects.push(
      expandAndWidth.buffer,
      vertexBatchIds.buffer,
      indices.buffer
    );

    return {
      indexDatatype:
        indices.BYTES_PER_ELEMENT === 2
          ? IndexDatatype.IndexDatatype.UNSIGNED_SHORT
          : IndexDatatype.IndexDatatype.UNSIGNED_INT,
      currentPositions: curPositions.buffer,
      previousPositions: prevPositions.buffer,
      nextPositions: nextPositions.buffer,
      expandAndWidth: expandAndWidth.buffer,
      batchIds: vertexBatchIds.buffer,
      indices: indices.buffer,
    };
  }
  var createVectorTilePolylines$1 = createTaskProcessorWorker(createVectorTilePolylines);

  return createVectorTilePolylines$1;

});