jsketcher/web/app/brep/operations/boolean.js

import * as BREPBuilder from '../brep-builder';
import {BREPValidator} from '../brep-validator';
import {HalfEdge, Edge} from '../topo/edge';
import {Loop} from '../topo/loop';
import {Face} from '../topo/face';
import {Shell} from '../topo/shell';
import {Vertex} from '../topo/vertex';
import {Line} from '../geom/impl/line';
import Vector from '../../math/vector';
import * as math from '../../math/math';

export const TOLERANCE = 1e-8;
export const TOLERANCE_SQ = TOLERANCE * TOLERANCE;

const TYPE = {
  UNION: 0,
  INTERSECT: 1,
  SUBTRACT: 2
};

export function union( shell1, shell2 ) {
  return BooleanAlgorithm(shell1, shell2, TYPE.UNION);
}

export function intersect( shell1, shell2 ) {
  return BooleanAlgorithm(shell1, shell2, TYPE.INTERSECT);
}

export function subtract( shell1, shell2 ) {
  invert(shell2);
  return BooleanAlgorithm(shell1, shell2, TYPE.SUBTRACT);
}

export function invert( shell ) {
  for (let face of shell.faces) {
    face.surface = face.surface.invert();
    invertLoop(face.outerLoop);
  }
  BREPValidator.validateToConsole(shell);
}

function invertLoop(loop) {
  for (let halfEdge of loop.halfEdges) {
    const t = halfEdge.vertexA;
    halfEdge.vertexA = halfEdge.vertexB;
    halfEdge.vertexB = t;
  }
  loop.halfEdges.reverse();
  BREPBuilder.linkSegments(loop.halfEdges);
}

export function BooleanAlgorithm( shell1, shell2, type ) {

  __DEBUG__.Clear();
  
  let facesData = [];
  
  initSolveData(shell1, facesData);
  initSolveData(shell2, facesData);
  
  mergeVertices(shell1, shell2);
  markOverlappingFaces(shell1, shell2);
  intersectFaces(shell1, shell2, type !== TYPE.UNION);
  mergeOverlappingFaces(shell1, shell2);
  facesData = facesData.filter(fd => fd.merged !== true);
  
  for (let faceData of facesData) {
    fixOppositeEdges(faceData);
    fixCoincidentEdges(faceData, type === TYPE.UNION)
  }

    const allFaces = [];
  //__DEBUG__.AddSegment(shell2.faces[0].outerLoop.halfEdges[0].vertexA.point, shell2.faces[0].outerLoop.halfEdges[0].vertexB.point)
  const newLoops = new Set();
  for (let faceData of facesData) {
    const face = faceData.face;
    //__DEBUG__.Clear();
    //for (let l of face.loops) l.halfEdges.forEach(he => __DEBUG__.AddHalfEdge(he, 0x00ff00));

    const loops = [];
    const seen = new Set();
    let edges = [];
    for (let e of face.edges) edges.push(e);
    //faceData.newEdges.sort(e => e.merged === true ? 0 : 1);
    faceData.newEdges.forEach(e => edges.push(e));
    edges = edges.filter(e => e.invalid !== true);
    while (true) {
      let edge = edges.pop();
      if (!edge) {
        break;
      }
      if (seen.has(edge)) {
        continue;
      }
      const loop = new Loop();
      while (edge) {
        //__DEBUG__.AddHalfEdge(edge);
        const isNew = faceData.newEdges.indexOf(edge) != -1;
        if (isNew) newLoops.add(loop);
        
        loop.halfEdges.push(edge);
        seen.add(edge);
        let candidates = faceData.vertexToEdge.get(edge.vertexB);
        if (!candidates) {
          break;
        }
        edge = findMaxTurningLeft(edge, candidates, face.surface.normal);
        if (seen.has(edge)) {
          break;
        }
      }

      if (loop.halfEdges[0].vertexA == loop.halfEdges[loop.halfEdges.length - 1].vertexB) {
        for (let halfEdge of loop.halfEdges) {
          halfEdge.loop = loop;
        }
        
        BREPBuilder.linkSegments(loop.halfEdges);
        loops.push(loop);
      }
    }
    loopsToFaces(face, loops, allFaces);
  }
  const result = new Shell();
  const faces = filterFaces(allFaces, newLoops);
  faces.forEach(face => {
    face.shell = result;
    result.faces.push(face);
  });

  BREPValidator.validateToConsole(result);
  return result;
}

function mergeVertices(shell1, shell2) {
  const toSwap = new Map();
  for (let v1 of shell1.vertices) {
    for (let v2 of shell2.vertices) {
      if (math.areVectorsEqual(v1.point, v2.point, TOLERANCE)) {
        toSwap.set(v2, v1);
      }
    }
  }

  for (let face of shell2.faces) {
    for (let h of face.edges) {
      const aSwap = toSwap.get(h.vertexA);
      const bSwap = toSwap.get(h.vertexB);
      if (aSwap) {
        h.vertexA = aSwap;
      }
      if (bSwap) {
        h.vertexB = bSwap;
      }
    }
  }
}

function markOverlappingFaces(shell1, shell2) {
  for (let face1 of shell1.faces) {
    for (let face2 of shell2.faces) {
      if (face1.surface.coplanarUnsigned(face2.surface, TOLERANCE)) {
        markOverlapping(face1, face2);
      }
    }
  }
}

function markOverlapping(face1, face2) {
  let data1 = face1.data[MY];
  let data2 = face2.data[MY];
  data1.overlaps.add(face2);
  data2.overlaps.add(face1);
}

function mergeOverlappingFaces(shell1, shell2) {
  for (let face1 of shell1.faces) {
    for (let face2 of shell2.faces) {
      if (face1.data[MY].overlaps.has(face2)) {
        doMergeOverlappingFaces(face1, face2);
      }
    }
  }
}

function doMergeOverlappingFaces(face1, face2) {
  let data1 = face1.data[MY];
  let data2 = face2.data[MY];

  
  function keepOnlyOneEqualEdge(face1, face2) {
    for (let ne of face1.data[MY].newEdges) {
      for (let loop of face2.loops) {
        for (let he of loop.halfEdges) {
          if (areEdgesEqual(ne, he)) {
            he.skipped = true;
            deleteEdge(he.edge);
          }
        }
      }
    }
  }

  function outAllOppositeEdges(face1, face2) {
    for (let ne of face1.data[MY].newEdges) {
      for (let loop of face2.loops) {
        for (let he of loop.halfEdges) {
          if (areEdgesOpposite(ne, he)) {
            ne.skipped = true;
            he.skipped = true;
            deleteEdge(ne.edge);
            deleteEdge(he.edge);
          }
        }
      }
    }
  }


  //keepOnlyOneEqualEdge(face1, face2);
  //keepOnlyOneEqualEdge(face2, face1);

  //outAllOppositeEdges(face1, face2);
  //outAllOppositeEdges(face2, face1);

  
  for (let ne of data1.newEdges) {
    for (let he of face2.edges) {
      if (areEdgesOpposite(ne, he)) { // UNION
        ne.skipped = true;
        he.skipped = true;
        deleteEdge(ne.edge);
        deleteEdge(he.edge);
      } else if (areEdgesEqual(ne, he)) { //INTERSECTION
        he.skipped = true;
        deleteEdge(he.edge);
      }
    }
  }

  for (let ne of data2.newEdges) {
    for (let he of face1.edges) {
      if (areEdgesOpposite(ne, he)) { // UNION
        ne.skipped = true;
        he.skipped = true;
        deleteEdge(ne.edge);
        deleteEdge(he.edge);
      } else if (areEdgesEqual(ne, he)) { //INTERSECTION
        ne.skipped = true;
        deleteEdge(ne.edge);
      }
    }
  }

  for (let h1 of face1.edges) {
    for (let h2 of face2.edges) {
      if (areEdgesEqual(h1, h2)) { //INTERSECTION
        h2.skipped = true;
        deleteEdge(h2);
      }
    }
  }

  data1.vertexToEdge.clear();
  const newEdges = [];
  const loops = [];

  function collectEdges(face) {
    for (let loop of face.loops) {
      const newLoop = new Loop();
      newLoop.face = face;
      for (let he of loop.halfEdges) {
        if (he.skipped === true) continue;
        addToListInMap(data1.vertexToEdge, he.vertexA, he);
        newLoop.halfEdges.push(he);
        he.loop = newLoop;
      }
      if (newLoop.halfEdges.length != 0) {
        loops.push(newLoop);
      }
    }
    for (let he of face.data[MY].newEdges) {
      if (he.skipped === true) continue;
      newEdges.push(he);
    }
  }

  collectEdges(face1);
  collectEdges(face2);

  face1.outerLoop = new Loop();
  face1.outerLoop.face = face1;
  
  face1.innerLoops = loops;
  data1.newEdges = [];
  for (let newEdge of newEdges) {
    addNewEdge(face1, newEdge);
  }
  data2.merged = true;
}

function areEdgesEqual(e1, e2) {
  return e1.vertexA == e2.vertexA && e1.vertexB == e2.vertexB;
}

function areEdgesOpposite(e1, e2) {
  return e1.vertexA == e2.vertexB && e1.vertexB == e2.vertexA;
}


function fixOppositeEdges(faceData) {
  //corner case there a point on edge ____V____ 
  for (let i = 0; i < faceData.newEdges.length; ++i) {
    const e1 = faceData.newEdges[i];
    if (e1 == null) continue;
    for (let j = 0; j < faceData.newEdges.length; ++j) {
      if (i == j) continue;
      const e2 = faceData.newEdges[j];
      if (e2 == null) continue;
      if (areEdgesOpposite(e1, e2)) {
        deleteEdge(e1.edge);
        deleteEdge(e2.edge);
        faceData.newEdges[i] = null;
        faceData.newEdges[j] = null;
        break;
      }
    }
  }
  faceData.newEdges = faceData.newEdges.filter(e => e != null);
}

function fixCoincidentEdges(faceData, union) {
  
  const newEdges = [];
  for (let i = 0; i < faceData.newEdges.length; ++i) {
    const e1 = faceData.newEdges[i];
    let choice = e1;
    for (let j = 0; j < faceData.newEdges.length; ++j) {
      if (i == j) continue;
      const e2 = faceData.newEdges[j];
      if (areEdgesEqual(e1, e2)) {

        const face1 = e1.twin().loop.face;
        const face2 = e2.twin().loop.face;
        const op = e1.twin();
        
        function find(face, edge) {
          for (let loop of face.loops) {
            for (let he of loop.halfEdges) {
              if (areEdgesEqual(edge, he)) {
                return he;
              }
            }
          }
        }
        
        function findAndRemove(face, edge) {
          const found = find(face, edge);
          if (found != null) {
            deleteHalfEdge(found);
            return true;
          }
          return false;
        }
        
        if (findAndRemove(face1, op)) {
          choice = e1;
        }
        if (findAndRemove(face1, e1)) {
          deleteEdge(e1.edge);         
        }

        if (findAndRemove(face2, op)) {
          choice = e2;
        }
        if (findAndRemove(face2, e1)) {
          deleteEdge(e2.edge);
        }
        
        break;  
      }
    }
    newEdges.push(choice);
  }
  faceData.newEdges = newEdges;
}

function findCoincidentEdgeOnFace(edge, face) {
  for (let loop of face.loops) {
    const coi = findCoincidentEdge(edge, loop.halfEdges);
    if (coi != null) {
      return coi;
    }
  }
  return null;
}

function findCoincidentEdge(edge, edges) {
  for (let he of edges) {
    if (areEdgesEqual(edge, he)) {
      return he;
    }
  }
  return null;
}

function filterFaces(faces, newLoops, validLoops) {
  const validFaces = new Set(faces);
  const result = new Set();
  for (let face of faces) {
    traverseFaces(face, validFaces, (it) => {
      if (result.has(it) || isFaceContainNewLoop(it, newLoops)) {
        result.add(face);
        return true;
      }
    });
  }
  return result;
}

function isFaceContainNewLoop(face, newLoops) {
  for (let loop of face.loops) {
    if (newLoops.has(loop)) {
      return true;
    }
  }
  return false;
}

function traverseFaces(face, validFaces, callback) {
  const stack = [face];
  const seen = new Set();
  while (stack.length !== 0) {
    face = stack.pop();
    if (seen.has(face)) continue;
    seen.add(face);
    if (callback(face) === true) {
      return;
    }
    for (let loop of face.loops) {
      if (!validFaces.has(face)) continue;
      for (let halfEdge of loop.halfEdges) {
        const twin = halfEdge.twin();
        if (validFaces.has(twin.loop.face)) {
          stack.push(twin.loop.face)
        }
      }
    }
  }
}

function loopsToFaces(originFace, loops, out) {
  function createFaces(nestedLoop) {
    const loop = nestedLoop.loop;
    const newFace = new Face(originFace.surface);
    newFace.outerLoop = loop;
    loop.face = newFace;
    out.push(newFace);
    for (let child of nestedLoop.nesting) {
      if (child.loop.isCCW(originFace.surface)) {
        createFaces(child);
      } else {
        child.loop.face = newFace;
        newFace.innerLoops.push(child.loop);
      }
    }
  }
  const nestedLoops = getNestedLoops(originFace, loops);
  //loops.forEach(l => l.halfEdges.forEach(h => __DEBUG__.AddHalfEdge(h)))
  for (let nestedLoop of nestedLoops) {
    if (nestedLoop.loop.isCCW(originFace.surface)) {
      createFaces(nestedLoop);
    }
  }
}

function getNestedLoops(face, brepLoops) {
  const tr = face.surface.get2DTransformation();
  function NestedLoop(polygon, loop) {
    this.polygon = polygon;
    this.loop = loop;
    this.nesting = [];
    this.level = 0;
  }

  const loops = brepLoops.map(loop => {
    const polygon = loop.asPolygon().map(point => tr.apply(point));
    return new NestedLoop(polygon, loop);
  });
  function contains(polygon, other) {
    for (let point of other) {
      if (!math.isPointInsidePolygon(point, polygon)) {
        return false;
      }
    }
    return true;
  }
  for (let i = 0; i < loops.length; ++i) {
    const loop = loops[i];
    for (let j = 0; j < loops.length; ++j) {
      if (i == j) continue;
      const other = loops[j];
      if (contains(loop.polygon, other.polygon)) {
        loop.nesting.push(other);
        other.level ++;
      }
    }
  }
  return loops.filter(l => l.level == 0);
}


function initSolveData(shell, facesData) {
  for (let face of shell.faces) {
    const solveData = new FaceSolveData(face);
    facesData.push(solveData);
    face.data[MY] = solveData;
    for (let he of face.edges) {
      EdgeSolveData.clear(he);
      addToListInMap(solveData.vertexToEdge, he.vertexA, he);
    }
  }  
}

function findMaxTurningLeft(edge, edges, normal) {
  edges = edges.slice();
  function edgeVector(edge) {
    return edge.vertexB.point.minus(edge.vertexA.point)._normalize();
  }
  const edgeV = edgeVector(edge);
  function leftTurningMeasure(v1, v2) {
    let measure = v1.dot(v2);
    if (v1.cross(v2).dot(normal) < 0) {
      measure *= -1;
      measure += 2;
    }
    return measure 
  }
  edges.sort((e1, e2) => {
    return leftTurningMeasure(edgeV, edgeVector(e1)) - leftTurningMeasure(edgeV, edgeVector(e2));
  });
  return edges[0];
}

function intersectFaces(shell1, shell2, inverseCrossEdgeDirection) {
  for (let i = 0; i < shell1.faces.length; i++) {
    const face1 = shell1.faces[i];
    for (let j = 0; j < shell2.faces.length; j++) {
      const face2 = shell2.faces[j];
      //__DEBUG__.Clear();
      //for (let l of face1.loops) l.halfEdges.forEach(he => __DEBUG__.AddHalfEdge(he, 0x00ff00));
      //for (let l of face2.loops) l.halfEdges.forEach(he => __DEBUG__.AddHalfEdge(he, 0x0000ff));

      if (face1.data[MY].overlaps.has(face2)) {
        console.log("skip overlapping");
        continue;
      }
      
      const curve = face1.surface.intersect(face2.surface);
  
      const nodes = [];
      collectNodesOfIntersectionOfFace(face2, face1, nodes);
      collectNodesOfIntersectionOfFace(face1, face2, nodes);
      
      const newEdges = [];
      const direction = face1.surface.normal.cross(face2.surface.normal);
      if (inverseCrossEdgeDirection) {
        direction._multiply(-1);
      }
      filterDuplicateVertices(nodes);
      split(nodes, newEdges, curve, direction);

      newEdges.forEach(e => {
         //__DEBUG__.AddHalfEdge(e.halfEdge1);
        if (!faceContainsSimilarEdge(face1, e.halfEdge1) || !faceContainsSimilarEdge(face2, e.halfEdge2)) {
          addNewEdge(face1, e.halfEdge1);
          addNewEdge(face2, e.halfEdge2);
        } else {
          console.log("faceContainsSimilarEdge");
        }
      });
    }
  }
}

function addNewEdge(face, halfEdge) {
  if (faceContainsSimilarEdge(face, halfEdge)) {
    //return false;
  }
  var data = face.data[MY];
  data.newEdges.push(halfEdge);
  halfEdge.loop = data.loopOfNew;
  addToListInMap(data.vertexToEdge, halfEdge.vertexA, halfEdge);
  return true;
}

function filterDuplicateVertices(nodes) {
  for (let i = 0; i < nodes.length; i++) {
    const node1 = nodes[i];
    if (node1 == null) continue;
    for (let j = 0; j < nodes.length; j++) {
      if (i == j) continue;
      const node2 = nodes[j];
      if (node2 != null && node2.vertex == node1.vertex) {
        nodes[j] = null
      }
    }
  }
}

function faceContainsSimilarEdge(face, halfEdge) {
  for (let loop of face.loops) {
    for (let he of loop.halfEdges) {
      if (areEdgesEqual(halfEdge, he) || areEdgesOpposite(halfEdge, he)) {
        return true;
      }
    }
  }
  return false;
}

function collectNodesOfIntersectionOfFace(splittingFace, face, nodes) {
  
  //__DEBUG__.Clear();
  //for (let l of splittingFace.loops) l.halfEdges.forEach(he => __DEBUG__.AddHalfEdge(he, 0x00ff00));
  //for (let l of face.loops) l.halfEdges.forEach(he => __DEBUG__.AddHalfEdge(he, 0x0000ff));
  
  for (let loop of face.loops) {
    collectNodesOfIntersection(splittingFace, loop, nodes);
  }
}

function collectNodesOfIntersection(face, loop, nodes) {
  //__DEBUG__.Clear();
  //for (let l of face.loops) l.halfEdges.forEach(he => __DEBUG__.AddHalfEdge(he, 0x00ff00));
  //loop.halfEdges.forEach(he => __DEBUG__.AddHalfEdge(he, 0x00ffff));

  const verticesCases = new Set();
  for (let edge of loop.halfEdges) {
    //__DEBUG__.AddHalfEdge(edge);
    const edgeSolveData = EdgeSolveData.get(edge);
    if (edgeSolveData.skipFace.has(face)) {
      continue;
    }
    const preExistVertex = edgeSolveData.splitByFace.get(face);
    if (preExistVertex) {
      //__DEBUG__.AddVertex(preExistVertex);
      nodes.push(new Node(preExistVertex, edgeNormal(edge), edge, face));
      continue
    }
    intersectFaceWithEdge(face, edge, nodes, verticesCases);
  }
  //for (let he of loop.halfEdges) {
  //  if (verticesCases.has(he.vertexA) && verticesCases.has(he.vertexB)) {
  //    deleteEdge(he.edge);
  //  }
  //}  

}

function split(nodes, result, onCurve, direction) {
  for (let i = 0; i < nodes.length; i++) {
    let inNode = nodes[i];
    //if (i == 0)  __DEBUG__.AddPoint(inNode.vertex.point);

    if (inNode == null) continue;
    nodes[i] = null;
    let closestIdx = findCloserProjection(nodes, inNode);
    if (closestIdx == -1) {
      continue;
    }
    let outNode = nodes[closestIdx];
    //if (i == 1)  __DEBUG__.AddPoint(outNode.vertex.point);
    //if (i == 1)  __DEBUG__.AddSegment(inNode.point, inNode.point.plus(inNode.normal.multiply(1000)));
    //__DEBUG__.AddSegment(new Vector(),  outNode.normal.multiply(100));

    if (outNode.normal.dot(inNode.normal) > 0) {
      continue;
    }

    nodes[closestIdx] = null;

    //__DEBUG__.AddPoint(inNode.vertex.point);
    //__DEBUG__.AddPoint(outNode.vertex.point);


    const halfEdge1 = new HalfEdge();
    halfEdge1.vertexA = inNode.vertex;
    halfEdge1.vertexB = outNode.vertex;
    
    const halfEdge2 = new HalfEdge();
    halfEdge2.vertexB = halfEdge1.vertexA;
    halfEdge2.vertexA = halfEdge1.vertexB;

    //__DEBUG__.AddHalfEdge(halfEdge1);
    //__DEBUG__.AddSegment(new Vector(),  direction.multiply(100));


    splitEdgeByVertex(inNode.edge, halfEdge1.vertexA, inNode.splittingFace);
    splitEdgeByVertex(outNode.edge, halfEdge1.vertexB, outNode.splittingFace);

    const sameDirection = direction.dot(outNode.point.minus(inNode.point)) > 0;

    const halfEdgeSameDir = sameDirection ? halfEdge1 : halfEdge2;
    const halfEdgeNegativeDir = sameDirection ? halfEdge2 : halfEdge1;

    // cross edge should go with negative dir for the first face and positive for the second
    const edge = new Edge(onCurve);
    edge.halfEdge1 = halfEdgeNegativeDir;
    edge.halfEdge2 = halfEdgeSameDir;
    halfEdgeNegativeDir.edge = edge;
    halfEdgeSameDir.edge = edge;
    
    //check for corner case when to faces only intersects in edges
    if (!containsEdges(result, edge)) {
      result.push(edge);
    }
  }
}

function containsEdges(edges, edge) {
  for (let e of edges) {
    if (isSameEdge(e, edge)) {
      return true;
    }
  }
  return false;
}

function isSameEdge(e1, e2) {
  return areEdgesEqual(e1.halfEdge1, e2.halfEdge1);
}


function splitEdgeByVertex(originHalfEdge, vertex, splittingFace) {
  
  function splitHalfEdge(h) {
    const newEdge = new HalfEdge();
    newEdge.vertexA = vertex;
    newEdge.vertexB = h.vertexB;
    h.vertexB = newEdge.vertexA;
    addToListInMap(h.loop.face.data[MY].vertexToEdge, vertex, newEdge);
    return newEdge;
  }

  const orig = originHalfEdge;
  const twin = orig.twin();

  if (orig.vertexA == vertex || orig.vertexB == vertex) {
    return;
  }
  
  const newOrig = splitHalfEdge(orig);
  const newTwin = splitHalfEdge(twin);


  BREPBuilder.linkHalfEdges(orig.edge, orig, newTwin);
  BREPBuilder.linkHalfEdges(new Edge(orig.edge.curve), twin, newOrig);
  
  orig.loop.halfEdges.splice(orig.loop.halfEdges.indexOf(orig) + 1, 0, newOrig);
  twin.loop.halfEdges.splice(twin.loop.halfEdges.indexOf(twin) + 1, 0, newTwin);

  newOrig.loop = orig.loop;
  newTwin.loop = twin.loop;
  
  EdgeSolveData.transfer(orig, newOrig);
  EdgeSolveData.transfer(twin, newTwin);

  EdgeSolveData.createIfEmpty(twin).splitByFace.set(splittingFace, vertex);
  EdgeSolveData.createIfEmpty(newTwin).skipFace.add(splittingFace);
}

function findCloserProjection(nodes, toNode) {
  let hero = -1;
  let heroDistance = Number.MAX_VALUE;
  for (let i = 0; i < nodes.length; i++) {
    let node = nodes[i];
    if (node == null) continue;
    let projectionDistance = toNode.normal.dot(node.point.minus(toNode.point));
    if (projectionDistance > 0 && projectionDistance < heroDistance) {
      hero = i;
      heroDistance = projectionDistance;
    }
  }
  return hero;
}

function intersectFaceWithEdge(face, edge, result, vertecies) {

  if (vertecies.has(edge.vertexA) || vertecies.has(edge.vertexB)) {
    return;
  }

  const p0 = edge.vertexA.point;
  const ab = edge.vertexB.point.minus(p0);
  const length = ab.length();
  const v = ab._multiply(1 / length);
  if (math.areEqual(v.dot(face.surface.normal), 0, TOLERANCE_SQ)) {
    return; // we not consider edges parallel to the face
  }
  const edgeLine = new Line(p0, v);
  const t = edgeLine.intersectSurface(face.surface);
  if (t >= 0 && t <= length) {
    const pointOfIntersection = edgeLine.parametricEquation(t);
    //TODO: should check if point on an edge then exclude that edge from further intersection test cuz it would produce two identical Nodes
    //TODO: should check if point on a vertex then exclude two edges of the vertex from further intersection test cuz it would produce three identical Nodes
    const classRes = classifyPointToFace(pointOfIntersection, face);
    if (classRes.inside) {
      let vertexOfIntersection;
      if (classRes.vertex) {
        vertexOfIntersection = classRes.vertex;
      } else if (math.areVectorsEqual(edge.vertexA.point, pointOfIntersection, TOLERANCE)) {
        vertecies.add(edge.vertexA);
        vertexOfIntersection = edge.vertexA;
        //console.log("point A on surface");
      } else if (math.areVectorsEqual(edge.vertexB.point, pointOfIntersection, TOLERANCE)) {
        vertecies.add(edge.vertexB);
        vertexOfIntersection = edge.vertexB;
        //console.log("point B on surface");
      } else {
        vertexOfIntersection = new Vertex(pointOfIntersection);
        duplicatePointTest(pointOfIntersection);
      }

      const edgeNormal = edge.loop.face.surface.normal.cross(v)._normalize() ;
      const node = new Node(vertexOfIntersection, edgeNormal, edge);
      result.push(node);
      if (classRes.edge) {
        splitEdgeByVertex(classRes.edge, vertexOfIntersection, edge.loop.face);
      } 
    }
  }
}

function deleteEdge(edge) {
  if (edge.halfEdge1 != null) {
    deleteHalfEdge(edge.halfEdge1);
  }
  if (edge.halfEdge2 != null) {
    deleteHalfEdge(edge.halfEdge2);
  }
}

function deleteHalfEdge(he) {
  he.invalid = true;
  removeFromListInMap(he.loop.face.data[MY].vertexToEdge, he.vertexA, he);
}

function classifyPointToFace(point, face) {
  const tr = face.surface.get2DTransformation();
  const point2d = tr.apply(point);
  const result = classifyPointInsideLoop(point2d, face.outerLoop, tr);
  if (result.inside) {
    if (result.vertex || result.edge) {
      return result;
    } else {
      for (let innerLoop of face.innerLoops) {
        const innerResult = classifyPointInsideLoop(point2d, innerLoop, tr);
        if (innerResult.inside) {
          if (innerResult.vertex || innerResult.edge) {
            return innerResult;
          } else {
            return {inside: false};
          }
        }
      }
      return result;
    }
  }
  return result;
}

function pointInsidePolygon(point, polygon) {
  //TODO: absolutely unacceptable way. should be done honoring intersecting edges and vertices. see TODOs above
  return math.isPointInsidePolygon(point, polygon, TOLERANCE);
}

function edgeNormal(edge) {
  return edge.loop.face.surface.normal.cross( edge.vertexB.point.minus(edge.vertexA.point) )._normalize();
}

function intersectCurveWithEdge(curve, edge, surface, result) {
  const p0 = edge.vertexA.point;
  const ab = edge.vertexB.point.minus(p0);
  const length = ab.length();
  const v = ab._multiply(1 / length);
  const edgeLine = new Line(p0, v);
  const t = edgeLine.intersectCurve(curve, surface);
  if (t >= 0 && t <= length) {
    const pointOfIntersection = edgeLine.parametricEquation(t);
    const edgeNormal = surface.normal.cross(v)._normalize() ;
    result.push(new Node(pointOfIntersection, edgeNormal, edge));
  }
}

function EdgeSolveData() {
  this.splitByFace = new Map();
  this.skipFace = new Set();
}

EdgeSolveData.EMPTY = new EdgeSolveData();

EdgeSolveData.get = function(edge) {
  if (!edge.__edgeSolveData) {
    return EdgeSolveData.EMPTY;
  }
  return edge.__edgeSolveData;
};

EdgeSolveData.createIfEmpty = function(edge) {
  if (!edge.__edgeSolveData) {
    edge.__edgeSolveData = new EdgeSolveData();
  }
  return edge.__edgeSolveData;
};

EdgeSolveData.clear = function(edge) {
  delete edge.__edgeSolveData;
};

EdgeSolveData.transfer = function(from, to) {
  to.__edgeSolveData = from.__edgeSolveData;
};

function Node(vertex, normal, splitsEdge, splittingFace) {
  this.vertex = vertex;
  this.normal = normal;
  this.point = vertex.point;
  this.edge = splitsEdge;
  this.splittingFace = splittingFace;
  //__DEBUG__.AddPoint(this.point);
}


let __DEBUG_POINT_DUPS = [];
function duplicatePointTest(point, data) {
  data = data || {};
  let res = false;
  for (let entry of __DEBUG_POINT_DUPS) {
    let other = entry[0];
    if (math.areVectorsEqual(point, other, TOLERANCE)) {
      res = true;
      break;
    }
  }
  __DEBUG_POINT_DUPS.push([point, data]);
  if (res) {
    __DEBUG__.Clear();
    __DEBUG__.AddPoint(point);
    console.error('DUPLICATE DETECTED: ' + point)
  }
  return res;
}

class SolveData {
  constructor() {
    this.faceData = [];
  }
}

class FaceSolveData {
  constructor(face) {
    this.face = face;
    this.loopOfNew = new Loop();
    this.newEdges = this.loopOfNew.halfEdges;
    this.vertexToEdge = new Map();
    this.overlaps = new Set();
    this.loopOfNew.face = face;
  }
}

export function classifyPointInsideLoop( inPt, loop, tr ) {

  var EPSILON = TOLERANCE;
  
  function VertexResult(vertex) {
    this.inside = true;
    this.vertex = vertex;
  }

  function EdgeResult(edge) {
    this.inside = true;
    this.edge = edge;
  }
  
  const _2dCoords = new Map();
  for( let edge of loop.halfEdges ) {
    const p = tr.apply(edge.vertexA.point);
    if (math.areEqual(inPt.y, p.y, TOLERANCE) && math.areEqual(inPt.x, p.x, TOLERANCE)) {
      return new VertexResult(edge.vertexA);
    }
    _2dCoords.set(edge.vertexA, p);
  }

    // inPt on polygon contour => immediate success    or
  // toggling of inside/outside at every single! intersection point of an edge
  //  with the horizontal line through inPt, left of inPt
  //  not counting lowerY endpoints of edges and whole edges on that line
  var inside = false;
  for( let edge of loop.halfEdges ) {

    const a = _2dCoords.get(edge.vertexA);
    const b = _2dCoords.get(edge.vertexB);
    
    var edgeLowPt  = a;
    var edgeHighPt = b;

    var edgeDx = edgeHighPt.x - edgeLowPt.x;
    var edgeDy = edgeHighPt.y - edgeLowPt.y;

    if ( Math.abs(edgeDy) > EPSILON ) {			// not parallel
      if ( edgeDy < 0 ) {
        edgeLowPt  = b; edgeDx = - edgeDx;
        edgeHighPt = a; edgeDy = - edgeDy;
      }
      if ( ( inPt.y < edgeLowPt.y ) || ( inPt.y > edgeHighPt.y ) ) 		continue;

      if ( math.areEqual(inPt.y, edgeLowPt.y, TOLERANCE) ) {
        if ( math.areEqual(inPt.x, edgeLowPt.x, TOLERANCE) )		new VertexResult(edgeLowPt);		// inPt is on contour ?
        // continue;				// no intersection or edgeLowPt => doesn't count !!!
      } else {
        var perpEdge = edgeDy * (inPt.x - edgeLowPt.x) - edgeDx * (inPt.y - edgeLowPt.y);
        if ( math.areEqual(perpEdge, 0, TOLERANCE_SQ) ) return new EdgeResult(edge);		// inPt is on contour ?
        if ( perpEdge < 0 ) 				continue;
        inside = ! inside;		// true intersection left of inPt
      }
    } else {		// parallel or colinear
      if ( !math.areEqual(inPt.y, edgeLowPt.y, TOLERANCE) ) 		continue;			// parallel
      // egde lies on the same horizontal line as inPt
      if ( ( ( edgeHighPt.x <= inPt.x ) && ( inPt.x <= edgeLowPt.x ) ) ||
        ( ( edgeLowPt.x <= inPt.x ) && ( inPt.x <= edgeHighPt.x ) ) ) return	new EdgeResult(edge);	// inPt: Point on contour !
      // continue;
    }
  }

  return	{inside};
}


function addToListInMap(map, key, value) {
  let list = map.get(key);
  if (!list) {
    list = [];
    map.set(key, list);
  }
  list.push(value);
}

function removeFromListInMap(map, key, value) {
  let list = map.get(key);
  if (list) {
    const idx = list.indexOf(value);
    if (idx != -1) {
      list.splice(idx, 1);
    }
  }
}

const MY = '__BOOLEAN_ALGORITHM_DATA__'; 
let xxx = 0;