CorridorGeometry.js

import arrayFill from "./arrayFill.js";
import arrayRemoveDuplicates from "./arrayRemoveDuplicates.js";
import BoundingSphere from "./BoundingSphere.js";
import Cartesian3 from "./Cartesian3.js";
import Cartographic from "./Cartographic.js";
import Check from "./Check.js";
import ComponentDatatype from "./ComponentDatatype.js";
import CornerType from "./CornerType.js";
import CorridorGeometryLibrary from "./CorridorGeometryLibrary.js";
import defaultValue from "./defaultValue.js";
import defined from "./defined.js";
import Ellipsoid from "./Ellipsoid.js";
import Geometry from "./Geometry.js";
import GeometryAttribute from "./GeometryAttribute.js";
import GeometryAttributes from "./GeometryAttributes.js";
import GeometryOffsetAttribute from "./GeometryOffsetAttribute.js";
import IndexDatatype from "./IndexDatatype.js";
import CesiumMath from "./Math.js";
import PolygonPipeline from "./PolygonPipeline.js";
import PrimitiveType from "./PrimitiveType.js";
import Rectangle from "./Rectangle.js";
import VertexFormat from "./VertexFormat.js";

var cartesian1 = new Cartesian3();
var cartesian2 = new Cartesian3();
var cartesian3 = new Cartesian3();
var cartesian4 = new Cartesian3();
var cartesian5 = new Cartesian3();
var cartesian6 = new Cartesian3();

var scratch1 = new Cartesian3();
var scratch2 = new Cartesian3();

function scaleToSurface(positions, ellipsoid) {
  for (var i = 0; i < positions.length; i++) {
    positions[i] = ellipsoid.scaleToGeodeticSurface(positions[i], positions[i]);
  }
  return positions;
}

function addNormals(attr, normal, left, front, back, vertexFormat) {
  var normals = attr.normals;
  var tangents = attr.tangents;
  var bitangents = attr.bitangents;
  var forward = Cartesian3.normalize(
    Cartesian3.cross(left, normal, scratch1),
    scratch1
  );
  if (vertexFormat.normal) {
    CorridorGeometryLibrary.addAttribute(normals, normal, front, back);
  }
  if (vertexFormat.tangent) {
    CorridorGeometryLibrary.addAttribute(tangents, forward, front, back);
  }
  if (vertexFormat.bitangent) {
    CorridorGeometryLibrary.addAttribute(bitangents, left, front, back);
  }
}

function combine(computedPositions, vertexFormat, ellipsoid) {
  var positions = computedPositions.positions;
  var corners = computedPositions.corners;
  var endPositions = computedPositions.endPositions;
  var computedLefts = computedPositions.lefts;
  var computedNormals = computedPositions.normals;
  var attributes = new GeometryAttributes();
  var corner;
  var leftCount = 0;
  var rightCount = 0;
  var i;
  var indicesLength = 0;
  var length;
  for (i = 0; i < positions.length; i += 2) {
    length = positions[i].length - 3;
    leftCount += length; //subtracting 3 to account for duplicate points at corners
    indicesLength += length * 2;
    rightCount += positions[i + 1].length - 3;
  }
  leftCount += 3; //add back count for end positions
  rightCount += 3;
  for (i = 0; i < corners.length; i++) {
    corner = corners[i];
    var leftSide = corners[i].leftPositions;
    if (defined(leftSide)) {
      length = leftSide.length;
      leftCount += length;
      indicesLength += length;
    } else {
      length = corners[i].rightPositions.length;
      rightCount += length;
      indicesLength += length;
    }
  }

  var addEndPositions = defined(endPositions);
  var endPositionLength;
  if (addEndPositions) {
    endPositionLength = endPositions[0].length - 3;
    leftCount += endPositionLength;
    rightCount += endPositionLength;
    endPositionLength /= 3;
    indicesLength += endPositionLength * 6;
  }
  var size = leftCount + rightCount;
  var finalPositions = new Float64Array(size);
  var normals = vertexFormat.normal ? new Float32Array(size) : undefined;
  var tangents = vertexFormat.tangent ? new Float32Array(size) : undefined;
  var bitangents = vertexFormat.bitangent ? new Float32Array(size) : undefined;
  var attr = {
    normals: normals,
    tangents: tangents,
    bitangents: bitangents,
  };
  var front = 0;
  var back = size - 1;
  var UL, LL, UR, LR;
  var normal = cartesian1;
  var left = cartesian2;
  var rightPos, leftPos;
  var halfLength = endPositionLength / 2;

  var indices = IndexDatatype.createTypedArray(size / 3, indicesLength);
  var index = 0;
  if (addEndPositions) {
    // add rounded end
    leftPos = cartesian3;
    rightPos = cartesian4;
    var firstEndPositions = endPositions[0];
    normal = Cartesian3.fromArray(computedNormals, 0, normal);
    left = Cartesian3.fromArray(computedLefts, 0, left);
    for (i = 0; i < halfLength; i++) {
      leftPos = Cartesian3.fromArray(
        firstEndPositions,
        (halfLength - 1 - i) * 3,
        leftPos
      );
      rightPos = Cartesian3.fromArray(
        firstEndPositions,
        (halfLength + i) * 3,
        rightPos
      );
      CorridorGeometryLibrary.addAttribute(finalPositions, rightPos, front);
      CorridorGeometryLibrary.addAttribute(
        finalPositions,
        leftPos,
        undefined,
        back
      );
      addNormals(attr, normal, left, front, back, vertexFormat);

      LL = front / 3;
      LR = LL + 1;
      UL = (back - 2) / 3;
      UR = UL - 1;
      indices[index++] = UL;
      indices[index++] = LL;
      indices[index++] = UR;
      indices[index++] = UR;
      indices[index++] = LL;
      indices[index++] = LR;

      front += 3;
      back -= 3;
    }
  }

  var posIndex = 0;
  var compIndex = 0;
  var rightEdge = positions[posIndex++]; //add first two edges
  var leftEdge = positions[posIndex++];
  finalPositions.set(rightEdge, front);
  finalPositions.set(leftEdge, back - leftEdge.length + 1);

  left = Cartesian3.fromArray(computedLefts, compIndex, left);
  var rightNormal;
  var leftNormal;
  length = leftEdge.length - 3;
  for (i = 0; i < length; i += 3) {
    rightNormal = ellipsoid.geodeticSurfaceNormal(
      Cartesian3.fromArray(rightEdge, i, scratch1),
      scratch1
    );
    leftNormal = ellipsoid.geodeticSurfaceNormal(
      Cartesian3.fromArray(leftEdge, length - i, scratch2),
      scratch2
    );
    normal = Cartesian3.normalize(
      Cartesian3.add(rightNormal, leftNormal, normal),
      normal
    );
    addNormals(attr, normal, left, front, back, vertexFormat);

    LL = front / 3;
    LR = LL + 1;
    UL = (back - 2) / 3;
    UR = UL - 1;
    indices[index++] = UL;
    indices[index++] = LL;
    indices[index++] = UR;
    indices[index++] = UR;
    indices[index++] = LL;
    indices[index++] = LR;

    front += 3;
    back -= 3;
  }

  rightNormal = ellipsoid.geodeticSurfaceNormal(
    Cartesian3.fromArray(rightEdge, length, scratch1),
    scratch1
  );
  leftNormal = ellipsoid.geodeticSurfaceNormal(
    Cartesian3.fromArray(leftEdge, length, scratch2),
    scratch2
  );
  normal = Cartesian3.normalize(
    Cartesian3.add(rightNormal, leftNormal, normal),
    normal
  );
  compIndex += 3;
  for (i = 0; i < corners.length; i++) {
    var j;
    corner = corners[i];
    var l = corner.leftPositions;
    var r = corner.rightPositions;
    var pivot;
    var start;
    var outsidePoint = cartesian6;
    var previousPoint = cartesian3;
    var nextPoint = cartesian4;
    normal = Cartesian3.fromArray(computedNormals, compIndex, normal);
    if (defined(l)) {
      addNormals(attr, normal, left, undefined, back, vertexFormat);
      back -= 3;
      pivot = LR;
      start = UR;
      for (j = 0; j < l.length / 3; j++) {
        outsidePoint = Cartesian3.fromArray(l, j * 3, outsidePoint);
        indices[index++] = pivot;
        indices[index++] = start - j - 1;
        indices[index++] = start - j;
        CorridorGeometryLibrary.addAttribute(
          finalPositions,
          outsidePoint,
          undefined,
          back
        );
        previousPoint = Cartesian3.fromArray(
          finalPositions,
          (start - j - 1) * 3,
          previousPoint
        );
        nextPoint = Cartesian3.fromArray(finalPositions, pivot * 3, nextPoint);
        left = Cartesian3.normalize(
          Cartesian3.subtract(previousPoint, nextPoint, left),
          left
        );
        addNormals(attr, normal, left, undefined, back, vertexFormat);
        back -= 3;
      }
      outsidePoint = Cartesian3.fromArray(
        finalPositions,
        pivot * 3,
        outsidePoint
      );
      previousPoint = Cartesian3.subtract(
        Cartesian3.fromArray(finalPositions, start * 3, previousPoint),
        outsidePoint,
        previousPoint
      );
      nextPoint = Cartesian3.subtract(
        Cartesian3.fromArray(finalPositions, (start - j) * 3, nextPoint),
        outsidePoint,
        nextPoint
      );
      left = Cartesian3.normalize(
        Cartesian3.add(previousPoint, nextPoint, left),
        left
      );
      addNormals(attr, normal, left, front, undefined, vertexFormat);
      front += 3;
    } else {
      addNormals(attr, normal, left, front, undefined, vertexFormat);
      front += 3;
      pivot = UR;
      start = LR;
      for (j = 0; j < r.length / 3; j++) {
        outsidePoint = Cartesian3.fromArray(r, j * 3, outsidePoint);
        indices[index++] = pivot;
        indices[index++] = start + j;
        indices[index++] = start + j + 1;
        CorridorGeometryLibrary.addAttribute(
          finalPositions,
          outsidePoint,
          front
        );
        previousPoint = Cartesian3.fromArray(
          finalPositions,
          pivot * 3,
          previousPoint
        );
        nextPoint = Cartesian3.fromArray(
          finalPositions,
          (start + j) * 3,
          nextPoint
        );
        left = Cartesian3.normalize(
          Cartesian3.subtract(previousPoint, nextPoint, left),
          left
        );
        addNormals(attr, normal, left, front, undefined, vertexFormat);
        front += 3;
      }
      outsidePoint = Cartesian3.fromArray(
        finalPositions,
        pivot * 3,
        outsidePoint
      );
      previousPoint = Cartesian3.subtract(
        Cartesian3.fromArray(finalPositions, (start + j) * 3, previousPoint),
        outsidePoint,
        previousPoint
      );
      nextPoint = Cartesian3.subtract(
        Cartesian3.fromArray(finalPositions, start * 3, nextPoint),
        outsidePoint,
        nextPoint
      );
      left = Cartesian3.normalize(
        Cartesian3.negate(Cartesian3.add(nextPoint, previousPoint, left), left),
        left
      );
      addNormals(attr, normal, left, undefined, back, vertexFormat);
      back -= 3;
    }
    rightEdge = positions[posIndex++];
    leftEdge = positions[posIndex++];
    rightEdge.splice(0, 3); //remove duplicate points added by corner
    leftEdge.splice(leftEdge.length - 3, 3);
    finalPositions.set(rightEdge, front);
    finalPositions.set(leftEdge, back - leftEdge.length + 1);
    length = leftEdge.length - 3;

    compIndex += 3;
    left = Cartesian3.fromArray(computedLefts, compIndex, left);
    for (j = 0; j < leftEdge.length; j += 3) {
      rightNormal = ellipsoid.geodeticSurfaceNormal(
        Cartesian3.fromArray(rightEdge, j, scratch1),
        scratch1
      );
      leftNormal = ellipsoid.geodeticSurfaceNormal(
        Cartesian3.fromArray(leftEdge, length - j, scratch2),
        scratch2
      );
      normal = Cartesian3.normalize(
        Cartesian3.add(rightNormal, leftNormal, normal),
        normal
      );
      addNormals(attr, normal, left, front, back, vertexFormat);

      LR = front / 3;
      LL = LR - 1;
      UR = (back - 2) / 3;
      UL = UR + 1;
      indices[index++] = UL;
      indices[index++] = LL;
      indices[index++] = UR;
      indices[index++] = UR;
      indices[index++] = LL;
      indices[index++] = LR;

      front += 3;
      back -= 3;
    }
    front -= 3;
    back += 3;
  }
  normal = Cartesian3.fromArray(
    computedNormals,
    computedNormals.length - 3,
    normal
  );
  addNormals(attr, normal, left, front, back, vertexFormat);

  if (addEndPositions) {
    // add rounded end
    front += 3;
    back -= 3;
    leftPos = cartesian3;
    rightPos = cartesian4;
    var lastEndPositions = endPositions[1];
    for (i = 0; i < halfLength; i++) {
      leftPos = Cartesian3.fromArray(
        lastEndPositions,
        (endPositionLength - i - 1) * 3,
        leftPos
      );
      rightPos = Cartesian3.fromArray(lastEndPositions, i * 3, rightPos);
      CorridorGeometryLibrary.addAttribute(
        finalPositions,
        leftPos,
        undefined,
        back
      );
      CorridorGeometryLibrary.addAttribute(finalPositions, rightPos, front);
      addNormals(attr, normal, left, front, back, vertexFormat);

      LR = front / 3;
      LL = LR - 1;
      UR = (back - 2) / 3;
      UL = UR + 1;
      indices[index++] = UL;
      indices[index++] = LL;
      indices[index++] = UR;
      indices[index++] = UR;
      indices[index++] = LL;
      indices[index++] = LR;

      front += 3;
      back -= 3;
    }
  }

  attributes.position = new GeometryAttribute({
    componentDatatype: ComponentDatatype.DOUBLE,
    componentsPerAttribute: 3,
    values: finalPositions,
  });

  if (vertexFormat.st) {
    var st = new Float32Array((size / 3) * 2);
    var rightSt;
    var leftSt;
    var stIndex = 0;
    if (addEndPositions) {
      leftCount /= 3;
      rightCount /= 3;
      var theta = Math.PI / (endPositionLength + 1);
      leftSt = 1 / (leftCount - endPositionLength + 1);
      rightSt = 1 / (rightCount - endPositionLength + 1);
      var a;
      var halfEndPos = endPositionLength / 2;
      for (i = halfEndPos + 1; i < endPositionLength + 1; i++) {
        // lower left rounded end
        a = CesiumMath.PI_OVER_TWO + theta * i;
        st[stIndex++] = rightSt * (1 + Math.cos(a));
        st[stIndex++] = 0.5 * (1 + Math.sin(a));
      }
      for (i = 1; i < rightCount - endPositionLength + 1; i++) {
        // bottom edge
        st[stIndex++] = i * rightSt;
        st[stIndex++] = 0;
      }
      for (i = endPositionLength; i > halfEndPos; i--) {
        // lower right rounded end
        a = CesiumMath.PI_OVER_TWO - i * theta;
        st[stIndex++] = 1 - rightSt * (1 + Math.cos(a));
        st[stIndex++] = 0.5 * (1 + Math.sin(a));
      }
      for (i = halfEndPos; i > 0; i--) {
        // upper right rounded end
        a = CesiumMath.PI_OVER_TWO - theta * i;
        st[stIndex++] = 1 - leftSt * (1 + Math.cos(a));
        st[stIndex++] = 0.5 * (1 + Math.sin(a));
      }
      for (i = leftCount - endPositionLength; i > 0; i--) {
        // top edge
        st[stIndex++] = i * leftSt;
        st[stIndex++] = 1;
      }
      for (i = 1; i < halfEndPos + 1; i++) {
        // upper left rounded end
        a = CesiumMath.PI_OVER_TWO + theta * i;
        st[stIndex++] = leftSt * (1 + Math.cos(a));
        st[stIndex++] = 0.5 * (1 + Math.sin(a));
      }
    } else {
      leftCount /= 3;
      rightCount /= 3;
      leftSt = 1 / (leftCount - 1);
      rightSt = 1 / (rightCount - 1);
      for (i = 0; i < rightCount; i++) {
        // bottom edge
        st[stIndex++] = i * rightSt;
        st[stIndex++] = 0;
      }
      for (i = leftCount; i > 0; i--) {
        // top edge
        st[stIndex++] = (i - 1) * leftSt;
        st[stIndex++] = 1;
      }
    }

    attributes.st = new GeometryAttribute({
      componentDatatype: ComponentDatatype.FLOAT,
      componentsPerAttribute: 2,
      values: st,
    });
  }

  if (vertexFormat.normal) {
    attributes.normal = new GeometryAttribute({
      componentDatatype: ComponentDatatype.FLOAT,
      componentsPerAttribute: 3,
      values: attr.normals,
    });
  }

  if (vertexFormat.tangent) {
    attributes.tangent = new GeometryAttribute({
      componentDatatype: ComponentDatatype.FLOAT,
      componentsPerAttribute: 3,
      values: attr.tangents,
    });
  }

  if (vertexFormat.bitangent) {
    attributes.bitangent = new GeometryAttribute({
      componentDatatype: ComponentDatatype.FLOAT,
      componentsPerAttribute: 3,
      values: attr.bitangents,
    });
  }

  return {
    attributes: attributes,
    indices: indices,
  };
}

function extrudedAttributes(attributes, vertexFormat) {
  if (
    !vertexFormat.normal &&
    !vertexFormat.tangent &&
    !vertexFormat.bitangent &&
    !vertexFormat.st
  ) {
    return attributes;
  }
  var positions = attributes.position.values;
  var topNormals;
  var topBitangents;
  if (vertexFormat.normal || vertexFormat.bitangent) {
    topNormals = attributes.normal.values;
    topBitangents = attributes.bitangent.values;
  }
  var size = attributes.position.values.length / 18;
  var threeSize = size * 3;
  var twoSize = size * 2;
  var sixSize = threeSize * 2;
  var i;
  if (vertexFormat.normal || vertexFormat.bitangent || vertexFormat.tangent) {
    var normals = vertexFormat.normal
      ? new Float32Array(threeSize * 6)
      : undefined;
    var tangents = vertexFormat.tangent
      ? new Float32Array(threeSize * 6)
      : undefined;
    var bitangents = vertexFormat.bitangent
      ? new Float32Array(threeSize * 6)
      : undefined;
    var topPosition = cartesian1;
    var bottomPosition = cartesian2;
    var previousPosition = cartesian3;
    var normal = cartesian4;
    var tangent = cartesian5;
    var bitangent = cartesian6;
    var attrIndex = sixSize;
    for (i = 0; i < threeSize; i += 3) {
      var attrIndexOffset = attrIndex + sixSize;
      topPosition = Cartesian3.fromArray(positions, i, topPosition);
      bottomPosition = Cartesian3.fromArray(
        positions,
        i + threeSize,
        bottomPosition
      );
      previousPosition = Cartesian3.fromArray(
        positions,
        (i + 3) % threeSize,
        previousPosition
      );
      bottomPosition = Cartesian3.subtract(
        bottomPosition,
        topPosition,
        bottomPosition
      );
      previousPosition = Cartesian3.subtract(
        previousPosition,
        topPosition,
        previousPosition
      );
      normal = Cartesian3.normalize(
        Cartesian3.cross(bottomPosition, previousPosition, normal),
        normal
      );
      if (vertexFormat.normal) {
        CorridorGeometryLibrary.addAttribute(normals, normal, attrIndexOffset);
        CorridorGeometryLibrary.addAttribute(
          normals,
          normal,
          attrIndexOffset + 3
        );
        CorridorGeometryLibrary.addAttribute(normals, normal, attrIndex);
        CorridorGeometryLibrary.addAttribute(normals, normal, attrIndex + 3);
      }
      if (vertexFormat.tangent || vertexFormat.bitangent) {
        bitangent = Cartesian3.fromArray(topNormals, i, bitangent);
        if (vertexFormat.bitangent) {
          CorridorGeometryLibrary.addAttribute(
            bitangents,
            bitangent,
            attrIndexOffset
          );
          CorridorGeometryLibrary.addAttribute(
            bitangents,
            bitangent,
            attrIndexOffset + 3
          );
          CorridorGeometryLibrary.addAttribute(
            bitangents,
            bitangent,
            attrIndex
          );
          CorridorGeometryLibrary.addAttribute(
            bitangents,
            bitangent,
            attrIndex + 3
          );
        }

        if (vertexFormat.tangent) {
          tangent = Cartesian3.normalize(
            Cartesian3.cross(bitangent, normal, tangent),
            tangent
          );
          CorridorGeometryLibrary.addAttribute(
            tangents,
            tangent,
            attrIndexOffset
          );
          CorridorGeometryLibrary.addAttribute(
            tangents,
            tangent,
            attrIndexOffset + 3
          );
          CorridorGeometryLibrary.addAttribute(tangents, tangent, attrIndex);
          CorridorGeometryLibrary.addAttribute(
            tangents,
            tangent,
            attrIndex + 3
          );
        }
      }
      attrIndex += 6;
    }

    if (vertexFormat.normal) {
      normals.set(topNormals); //top
      for (i = 0; i < threeSize; i += 3) {
        //bottom normals
        normals[i + threeSize] = -topNormals[i];
        normals[i + threeSize + 1] = -topNormals[i + 1];
        normals[i + threeSize + 2] = -topNormals[i + 2];
      }
      attributes.normal.values = normals;
    } else {
      attributes.normal = undefined;
    }

    if (vertexFormat.bitangent) {
      bitangents.set(topBitangents); //top
      bitangents.set(topBitangents, threeSize); //bottom
      attributes.bitangent.values = bitangents;
    } else {
      attributes.bitangent = undefined;
    }

    if (vertexFormat.tangent) {
      var topTangents = attributes.tangent.values;
      tangents.set(topTangents); //top
      tangents.set(topTangents, threeSize); //bottom
      attributes.tangent.values = tangents;
    }
  }
  if (vertexFormat.st) {
    var topSt = attributes.st.values;
    var st = new Float32Array(twoSize * 6);
    st.set(topSt); //top
    st.set(topSt, twoSize); //bottom
    var index = twoSize * 2;

    for (var j = 0; j < 2; j++) {
      st[index++] = topSt[0];
      st[index++] = topSt[1];
      for (i = 2; i < twoSize; i += 2) {
        var s = topSt[i];
        var t = topSt[i + 1];
        st[index++] = s;
        st[index++] = t;
        st[index++] = s;
        st[index++] = t;
      }
      st[index++] = topSt[0];
      st[index++] = topSt[1];
    }
    attributes.st.values = st;
  }

  return attributes;
}

function addWallPositions(positions, index, wallPositions) {
  wallPositions[index++] = positions[0];
  wallPositions[index++] = positions[1];
  wallPositions[index++] = positions[2];
  for (var i = 3; i < positions.length; i += 3) {
    var x = positions[i];
    var y = positions[i + 1];
    var z = positions[i + 2];
    wallPositions[index++] = x;
    wallPositions[index++] = y;
    wallPositions[index++] = z;
    wallPositions[index++] = x;
    wallPositions[index++] = y;
    wallPositions[index++] = z;
  }
  wallPositions[index++] = positions[0];
  wallPositions[index++] = positions[1];
  wallPositions[index++] = positions[2];

  return wallPositions;
}

function computePositionsExtruded(params, vertexFormat) {
  var topVertexFormat = new VertexFormat({
    position: vertexFormat.position,
    normal:
      vertexFormat.normal || vertexFormat.bitangent || params.shadowVolume,
    tangent: vertexFormat.tangent,
    bitangent: vertexFormat.normal || vertexFormat.bitangent,
    st: vertexFormat.st,
  });
  var ellipsoid = params.ellipsoid;
  var computedPositions = CorridorGeometryLibrary.computePositions(params);
  var attr = combine(computedPositions, topVertexFormat, ellipsoid);
  var height = params.height;
  var extrudedHeight = params.extrudedHeight;
  var attributes = attr.attributes;
  var indices = attr.indices;
  var positions = attributes.position.values;
  var length = positions.length;
  var newPositions = new Float64Array(length * 6);
  var extrudedPositions = new Float64Array(length);
  extrudedPositions.set(positions);
  var wallPositions = new Float64Array(length * 4);

  positions = PolygonPipeline.scaleToGeodeticHeight(
    positions,
    height,
    ellipsoid
  );
  wallPositions = addWallPositions(positions, 0, wallPositions);
  extrudedPositions = PolygonPipeline.scaleToGeodeticHeight(
    extrudedPositions,
    extrudedHeight,
    ellipsoid
  );
  wallPositions = addWallPositions(
    extrudedPositions,
    length * 2,
    wallPositions
  );
  newPositions.set(positions);
  newPositions.set(extrudedPositions, length);
  newPositions.set(wallPositions, length * 2);
  attributes.position.values = newPositions;

  attributes = extrudedAttributes(attributes, vertexFormat);
  var i;
  var size = length / 3;
  if (params.shadowVolume) {
    var topNormals = attributes.normal.values;
    length = topNormals.length;

    var extrudeNormals = new Float32Array(length * 6);
    for (i = 0; i < length; i++) {
      topNormals[i] = -topNormals[i];
    }
    //only get normals for bottom layer that's going to be pushed down
    extrudeNormals.set(topNormals, length); //bottom face
    extrudeNormals = addWallPositions(topNormals, length * 4, extrudeNormals); //bottom wall
    attributes.extrudeDirection = new GeometryAttribute({
      componentDatatype: ComponentDatatype.FLOAT,
      componentsPerAttribute: 3,
      values: extrudeNormals,
    });
    if (!vertexFormat.normal) {
      attributes.normal = undefined;
    }
  }
  if (defined(params.offsetAttribute)) {
    var applyOffset = new Uint8Array(size * 6);
    if (params.offsetAttribute === GeometryOffsetAttribute.TOP) {
      applyOffset = arrayFill(applyOffset, 1, 0, size); // top face
      applyOffset = arrayFill(applyOffset, 1, size * 2, size * 4); // top wall
    } else {
      var applyOffsetValue =
        params.offsetAttribute === GeometryOffsetAttribute.NONE ? 0 : 1;
      applyOffset = arrayFill(applyOffset, applyOffsetValue);
    }
    attributes.applyOffset = new GeometryAttribute({
      componentDatatype: ComponentDatatype.UNSIGNED_BYTE,
      componentsPerAttribute: 1,
      values: applyOffset,
    });
  }

  var iLength = indices.length;
  var twoSize = size + size;
  var newIndices = IndexDatatype.createTypedArray(
    newPositions.length / 3,
    iLength * 2 + twoSize * 3
  );
  newIndices.set(indices);
  var index = iLength;
  for (i = 0; i < iLength; i += 3) {
    // bottom indices
    var v0 = indices[i];
    var v1 = indices[i + 1];
    var v2 = indices[i + 2];
    newIndices[index++] = v2 + size;
    newIndices[index++] = v1 + size;
    newIndices[index++] = v0 + size;
  }

  var UL, LL, UR, LR;

  for (i = 0; i < twoSize; i += 2) {
    //wall indices
    UL = i + twoSize;
    LL = UL + twoSize;
    UR = UL + 1;
    LR = LL + 1;
    newIndices[index++] = UL;
    newIndices[index++] = LL;
    newIndices[index++] = UR;
    newIndices[index++] = UR;
    newIndices[index++] = LL;
    newIndices[index++] = LR;
  }

  return {
    attributes: attributes,
    indices: newIndices,
  };
}

var scratchCartesian1 = new Cartesian3();
var scratchCartesian2 = new Cartesian3();
var scratchCartographic = new Cartographic();

function computeOffsetPoints(
  position1,
  position2,
  ellipsoid,
  halfWidth,
  min,
  max
) {
  // Compute direction of offset the point
  var direction = Cartesian3.subtract(position2, position1, scratchCartesian1);
  Cartesian3.normalize(direction, direction);
  var normal = ellipsoid.geodeticSurfaceNormal(position1, scratchCartesian2);
  var offsetDirection = Cartesian3.cross(direction, normal, scratchCartesian1);
  Cartesian3.multiplyByScalar(offsetDirection, halfWidth, offsetDirection);

  var minLat = min.latitude;
  var minLon = min.longitude;
  var maxLat = max.latitude;
  var maxLon = max.longitude;

  // Compute 2 offset points
  Cartesian3.add(position1, offsetDirection, scratchCartesian2);
  ellipsoid.cartesianToCartographic(scratchCartesian2, scratchCartographic);

  var lat = scratchCartographic.latitude;
  var lon = scratchCartographic.longitude;
  minLat = Math.min(minLat, lat);
  minLon = Math.min(minLon, lon);
  maxLat = Math.max(maxLat, lat);
  maxLon = Math.max(maxLon, lon);

  Cartesian3.subtract(position1, offsetDirection, scratchCartesian2);
  ellipsoid.cartesianToCartographic(scratchCartesian2, scratchCartographic);

  lat = scratchCartographic.latitude;
  lon = scratchCartographic.longitude;
  minLat = Math.min(minLat, lat);
  minLon = Math.min(minLon, lon);
  maxLat = Math.max(maxLat, lat);
  maxLon = Math.max(maxLon, lon);

  min.latitude = minLat;
  min.longitude = minLon;
  max.latitude = maxLat;
  max.longitude = maxLon;
}

var scratchCartesianOffset = new Cartesian3();
var scratchCartesianEnds = new Cartesian3();
var scratchCartographicMin = new Cartographic();
var scratchCartographicMax = new Cartographic();

function computeRectangle(positions, ellipsoid, width, cornerType, result) {
  positions = scaleToSurface(positions, ellipsoid);
  var cleanPositions = arrayRemoveDuplicates(
    positions,
    Cartesian3.equalsEpsilon
  );
  var length = cleanPositions.length;
  if (length < 2 || width <= 0) {
    return new Rectangle();
  }
  var halfWidth = width * 0.5;

  scratchCartographicMin.latitude = Number.POSITIVE_INFINITY;
  scratchCartographicMin.longitude = Number.POSITIVE_INFINITY;
  scratchCartographicMax.latitude = Number.NEGATIVE_INFINITY;
  scratchCartographicMax.longitude = Number.NEGATIVE_INFINITY;

  var lat, lon;
  if (cornerType === CornerType.ROUNDED) {
    // Compute start cap
    var first = cleanPositions[0];
    Cartesian3.subtract(first, cleanPositions[1], scratchCartesianOffset);
    Cartesian3.normalize(scratchCartesianOffset, scratchCartesianOffset);
    Cartesian3.multiplyByScalar(
      scratchCartesianOffset,
      halfWidth,
      scratchCartesianOffset
    );
    Cartesian3.add(first, scratchCartesianOffset, scratchCartesianEnds);

    ellipsoid.cartesianToCartographic(
      scratchCartesianEnds,
      scratchCartographic
    );
    lat = scratchCartographic.latitude;
    lon = scratchCartographic.longitude;
    scratchCartographicMin.latitude = Math.min(
      scratchCartographicMin.latitude,
      lat
    );
    scratchCartographicMin.longitude = Math.min(
      scratchCartographicMin.longitude,
      lon
    );
    scratchCartographicMax.latitude = Math.max(
      scratchCartographicMax.latitude,
      lat
    );
    scratchCartographicMax.longitude = Math.max(
      scratchCartographicMax.longitude,
      lon
    );
  }

  // Compute the rest
  for (var i = 0; i < length - 1; ++i) {
    computeOffsetPoints(
      cleanPositions[i],
      cleanPositions[i + 1],
      ellipsoid,
      halfWidth,
      scratchCartographicMin,
      scratchCartographicMax
    );
  }

  // Compute ending point
  var last = cleanPositions[length - 1];
  Cartesian3.subtract(last, cleanPositions[length - 2], scratchCartesianOffset);
  Cartesian3.normalize(scratchCartesianOffset, scratchCartesianOffset);
  Cartesian3.multiplyByScalar(
    scratchCartesianOffset,
    halfWidth,
    scratchCartesianOffset
  );
  Cartesian3.add(last, scratchCartesianOffset, scratchCartesianEnds);
  computeOffsetPoints(
    last,
    scratchCartesianEnds,
    ellipsoid,
    halfWidth,
    scratchCartographicMin,
    scratchCartographicMax
  );

  if (cornerType === CornerType.ROUNDED) {
    // Compute end cap
    ellipsoid.cartesianToCartographic(
      scratchCartesianEnds,
      scratchCartographic
    );
    lat = scratchCartographic.latitude;
    lon = scratchCartographic.longitude;
    scratchCartographicMin.latitude = Math.min(
      scratchCartographicMin.latitude,
      lat
    );
    scratchCartographicMin.longitude = Math.min(
      scratchCartographicMin.longitude,
      lon
    );
    scratchCartographicMax.latitude = Math.max(
      scratchCartographicMax.latitude,
      lat
    );
    scratchCartographicMax.longitude = Math.max(
      scratchCartographicMax.longitude,
      lon
    );
  }

  var rectangle = defined(result) ? result : new Rectangle();
  rectangle.north = scratchCartographicMax.latitude;
  rectangle.south = scratchCartographicMin.latitude;
  rectangle.east = scratchCartographicMax.longitude;
  rectangle.west = scratchCartographicMin.longitude;

  return rectangle;
}

/**
 * A description of a corridor. Corridor geometry can be rendered with both {@link Primitive} and {@link GroundPrimitive}.
 *
 * @alias CorridorGeometry
 * @constructor
 *
 * @param {Object} options Object with the following properties:
 * @param {Cartesian3[]} options.positions An array of positions that define the center of the corridor.
 * @param {Number} options.width The distance between the edges of the corridor in meters.
 * @param {Ellipsoid} [options.ellipsoid=Ellipsoid.WGS84] The ellipsoid to be used as a reference.
 * @param {Number} [options.granularity=CesiumMath.RADIANS_PER_DEGREE] The distance, in radians, between each latitude and longitude. Determines the number of positions in the buffer.
 * @param {Number} [options.height=0] The distance in meters between the ellipsoid surface and the positions.
 * @param {Number} [options.extrudedHeight] The distance in meters between the ellipsoid surface and the extruded face.
 * @param {VertexFormat} [options.vertexFormat=VertexFormat.DEFAULT] The vertex attributes to be computed.
 * @param {CornerType} [options.cornerType=CornerType.ROUNDED] Determines the style of the corners.
 *
 * @see CorridorGeometry.createGeometry
 * @see Packable
 *
 * @demo {@link https://sandcastle.cesium.com/index.html?src=Corridor.html|Cesium Sandcastle Corridor Demo}
 *
 * @example
 * var corridor = new Cesium.CorridorGeometry({
 *   vertexFormat : Cesium.VertexFormat.POSITION_ONLY,
 *   positions : Cesium.Cartesian3.fromDegreesArray([-72.0, 40.0, -70.0, 35.0]),
 *   width : 100000
 * });
 */
function CorridorGeometry(options) {
  options = defaultValue(options, defaultValue.EMPTY_OBJECT);
  var positions = options.positions;
  var width = options.width;

  //>>includeStart('debug', pragmas.debug);
  Check.defined("options.positions", positions);
  Check.defined("options.width", width);
  //>>includeEnd('debug');

  var height = defaultValue(options.height, 0.0);
  var extrudedHeight = defaultValue(options.extrudedHeight, height);

  this._positions = positions;
  this._ellipsoid = Ellipsoid.clone(
    defaultValue(options.ellipsoid, Ellipsoid.WGS84)
  );
  this._vertexFormat = VertexFormat.clone(
    defaultValue(options.vertexFormat, VertexFormat.DEFAULT)
  );
  this._width = width;
  this._height = Math.max(height, extrudedHeight);
  this._extrudedHeight = Math.min(height, extrudedHeight);
  this._cornerType = defaultValue(options.cornerType, CornerType.ROUNDED);
  this._granularity = defaultValue(
    options.granularity,
    CesiumMath.RADIANS_PER_DEGREE
  );
  this._shadowVolume = defaultValue(options.shadowVolume, false);
  this._workerName = "createCorridorGeometry";
  this._offsetAttribute = options.offsetAttribute;
  this._rectangle = undefined;

  /**
   * The number of elements used to pack the object into an array.
   * @type {Number}
   */
  this.packedLength =
    1 +
    positions.length * Cartesian3.packedLength +
    Ellipsoid.packedLength +
    VertexFormat.packedLength +
    7;
}

/**
 * Stores the provided instance into the provided array.
 *
 * @param {CorridorGeometry} value The value to pack.
 * @param {Number[]} array The array to pack into.
 * @param {Number} [startingIndex=0] The index into the array at which to start packing the elements.
 *
 * @returns {Number[]} The array that was packed into
 */
CorridorGeometry.pack = function (value, array, startingIndex) {
  //>>includeStart('debug', pragmas.debug);
  Check.defined("value", value);
  Check.defined("array", array);
  //>>includeEnd('debug');

  startingIndex = defaultValue(startingIndex, 0);

  var positions = value._positions;
  var length = positions.length;
  array[startingIndex++] = length;

  for (var i = 0; i < length; ++i, startingIndex += Cartesian3.packedLength) {
    Cartesian3.pack(positions[i], array, startingIndex);
  }

  Ellipsoid.pack(value._ellipsoid, array, startingIndex);
  startingIndex += Ellipsoid.packedLength;

  VertexFormat.pack(value._vertexFormat, array, startingIndex);
  startingIndex += VertexFormat.packedLength;

  array[startingIndex++] = value._width;
  array[startingIndex++] = value._height;
  array[startingIndex++] = value._extrudedHeight;
  array[startingIndex++] = value._cornerType;
  array[startingIndex++] = value._granularity;
  array[startingIndex++] = value._shadowVolume ? 1.0 : 0.0;
  array[startingIndex] = defaultValue(value._offsetAttribute, -1);

  return array;
};

var scratchEllipsoid = Ellipsoid.clone(Ellipsoid.UNIT_SPHERE);
var scratchVertexFormat = new VertexFormat();
var scratchOptions = {
  positions: undefined,
  ellipsoid: scratchEllipsoid,
  vertexFormat: scratchVertexFormat,
  width: undefined,
  height: undefined,
  extrudedHeight: undefined,
  cornerType: undefined,
  granularity: undefined,
  shadowVolume: undefined,
  offsetAttribute: undefined,
};

/**
 * Retrieves an instance from a packed array.
 *
 * @param {Number[]} array The packed array.
 * @param {Number} [startingIndex=0] The starting index of the element to be unpacked.
 * @param {CorridorGeometry} [result] The object into which to store the result.
 * @returns {CorridorGeometry} The modified result parameter or a new CorridorGeometry instance if one was not provided.
 */
CorridorGeometry.unpack = function (array, startingIndex, result) {
  //>>includeStart('debug', pragmas.debug);
  Check.defined("array", array);
  //>>includeEnd('debug');

  startingIndex = defaultValue(startingIndex, 0);

  var length = array[startingIndex++];
  var positions = new Array(length);

  for (var i = 0; i < length; ++i, startingIndex += Cartesian3.packedLength) {
    positions[i] = Cartesian3.unpack(array, startingIndex);
  }

  var ellipsoid = Ellipsoid.unpack(array, startingIndex, scratchEllipsoid);
  startingIndex += Ellipsoid.packedLength;

  var vertexFormat = VertexFormat.unpack(
    array,
    startingIndex,
    scratchVertexFormat
  );
  startingIndex += VertexFormat.packedLength;

  var width = array[startingIndex++];
  var height = array[startingIndex++];
  var extrudedHeight = array[startingIndex++];
  var cornerType = array[startingIndex++];
  var granularity = array[startingIndex++];
  var shadowVolume = array[startingIndex++] === 1.0;
  var offsetAttribute = array[startingIndex];

  if (!defined(result)) {
    scratchOptions.positions = positions;
    scratchOptions.width = width;
    scratchOptions.height = height;
    scratchOptions.extrudedHeight = extrudedHeight;
    scratchOptions.cornerType = cornerType;
    scratchOptions.granularity = granularity;
    scratchOptions.shadowVolume = shadowVolume;
    scratchOptions.offsetAttribute =
      offsetAttribute === -1 ? undefined : offsetAttribute;

    return new CorridorGeometry(scratchOptions);
  }

  result._positions = positions;
  result._ellipsoid = Ellipsoid.clone(ellipsoid, result._ellipsoid);
  result._vertexFormat = VertexFormat.clone(vertexFormat, result._vertexFormat);
  result._width = width;
  result._height = height;
  result._extrudedHeight = extrudedHeight;
  result._cornerType = cornerType;
  result._granularity = granularity;
  result._shadowVolume = shadowVolume;
  result._offsetAttribute =
    offsetAttribute === -1 ? undefined : offsetAttribute;

  return result;
};

/**
 * Computes the bounding rectangle given the provided options
 *
 * @param {Object} options Object with the following properties:
 * @param {Cartesian3[]} options.positions An array of positions that define the center of the corridor.
 * @param {Number} options.width The distance between the edges of the corridor in meters.
 * @param {Ellipsoid} [options.ellipsoid=Ellipsoid.WGS84] The ellipsoid to be used as a reference.
 * @param {CornerType} [options.cornerType=CornerType.ROUNDED] Determines the style of the corners.
 * @param {Rectangle} [result] An object in which to store the result.
 *
 * @returns {Rectangle} The result rectangle.
 */
CorridorGeometry.computeRectangle = function (options, result) {
  options = defaultValue(options, defaultValue.EMPTY_OBJECT);
  var positions = options.positions;
  var width = options.width;

  //>>includeStart('debug', pragmas.debug);
  Check.defined("options.positions", positions);
  Check.defined("options.width", width);
  //>>includeEnd('debug');

  var ellipsoid = defaultValue(options.ellipsoid, Ellipsoid.WGS84);
  var cornerType = defaultValue(options.cornerType, CornerType.ROUNDED);

  return computeRectangle(positions, ellipsoid, width, cornerType, result);
};

/**
 * Computes the geometric representation of a corridor, including its vertices, indices, and a bounding sphere.
 *
 * @param {CorridorGeometry} corridorGeometry A description of the corridor.
 * @returns {Geometry|undefined} The computed vertices and indices.
 */
CorridorGeometry.createGeometry = function (corridorGeometry) {
  var positions = corridorGeometry._positions;
  var width = corridorGeometry._width;
  var ellipsoid = corridorGeometry._ellipsoid;

  positions = scaleToSurface(positions, ellipsoid);
  var cleanPositions = arrayRemoveDuplicates(
    positions,
    Cartesian3.equalsEpsilon
  );

  if (cleanPositions.length < 2 || width <= 0) {
    return;
  }

  var height = corridorGeometry._height;
  var extrudedHeight = corridorGeometry._extrudedHeight;
  var extrude = !CesiumMath.equalsEpsilon(
    height,
    extrudedHeight,
    0,
    CesiumMath.EPSILON2
  );

  var vertexFormat = corridorGeometry._vertexFormat;
  var params = {
    ellipsoid: ellipsoid,
    positions: cleanPositions,
    width: width,
    cornerType: corridorGeometry._cornerType,
    granularity: corridorGeometry._granularity,
    saveAttributes: true,
  };
  var attr;
  if (extrude) {
    params.height = height;
    params.extrudedHeight = extrudedHeight;
    params.shadowVolume = corridorGeometry._shadowVolume;
    params.offsetAttribute = corridorGeometry._offsetAttribute;
    attr = computePositionsExtruded(params, vertexFormat);
  } else {
    var computedPositions = CorridorGeometryLibrary.computePositions(params);
    attr = combine(computedPositions, vertexFormat, ellipsoid);
    attr.attributes.position.values = PolygonPipeline.scaleToGeodeticHeight(
      attr.attributes.position.values,
      height,
      ellipsoid
    );

    if (defined(corridorGeometry._offsetAttribute)) {
      var applyOffsetValue =
        corridorGeometry._offsetAttribute === GeometryOffsetAttribute.NONE
          ? 0
          : 1;
      var length = attr.attributes.position.values.length;
      var applyOffset = new Uint8Array(length / 3);
      arrayFill(applyOffset, applyOffsetValue);
      attr.attributes.applyOffset = new GeometryAttribute({
        componentDatatype: ComponentDatatype.UNSIGNED_BYTE,
        componentsPerAttribute: 1,
        values: applyOffset,
      });
    }
  }
  var attributes = attr.attributes;
  var boundingSphere = BoundingSphere.fromVertices(
    attributes.position.values,
    undefined,
    3
  );
  if (!vertexFormat.position) {
    attr.attributes.position.values = undefined;
  }

  return new Geometry({
    attributes: attributes,
    indices: attr.indices,
    primitiveType: PrimitiveType.TRIANGLES,
    boundingSphere: boundingSphere,
    offsetAttribute: corridorGeometry._offsetAttribute,
  });
};

/**
 * @private
 */
CorridorGeometry.createShadowVolume = function (
  corridorGeometry,
  minHeightFunc,
  maxHeightFunc
) {
  var granularity = corridorGeometry._granularity;
  var ellipsoid = corridorGeometry._ellipsoid;

  var minHeight = minHeightFunc(granularity, ellipsoid);
  var maxHeight = maxHeightFunc(granularity, ellipsoid);

  return new CorridorGeometry({
    positions: corridorGeometry._positions,
    width: corridorGeometry._width,
    cornerType: corridorGeometry._cornerType,
    ellipsoid: ellipsoid,
    granularity: granularity,
    extrudedHeight: minHeight,
    height: maxHeight,
    vertexFormat: VertexFormat.POSITION_ONLY,
    shadowVolume: true,
  });
};

Object.defineProperties(CorridorGeometry.prototype, {
  /**
   * @private
   */
  rectangle: {
    get: function () {
      if (!defined(this._rectangle)) {
        this._rectangle = computeRectangle(
          this._positions,
          this._ellipsoid,
          this._width,
          this._cornerType
        );
      }
      return this._rectangle;
    },
  },
  /**
   * For remapping texture coordinates when rendering CorridorGeometries as GroundPrimitives.
   *
   * Corridors don't support stRotation,
   * so just return the corners of the original system.
   * @private
   */
  textureCoordinateRotationPoints: {
    get: function () {
      return [0, 0, 0, 1, 1, 0];
    },
  },
});
export default CorridorGeometry;