@rxflow/manhattan/cjs/utils/route.js

Manhattan routing algorithm for ReactFlow - generates orthogonal paths with obstacle avoidance

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.getCost = getCost;
exports.getKey = getKey;
exports.normalizePoint = normalizePoint;
exports.reconstructRoute = reconstructRoute;
var _geometry = require("../geometry");
/**
 * Normalize a point to a unit direction vector
 */
function normalizePoint(point) {
  return new _geometry.Point(point.x === 0 ? 0 : Math.abs(point.x) / point.x, point.y === 0 ? 0 : Math.abs(point.y) / point.y);
}

/**
 * Get string key for a point
 */
function getKey(point) {
  return point.toString();
}

/**
 * Calculate minimum Manhattan distance from a point to multiple anchors
 */
function getCost(from, anchors) {
  let min = Infinity;
  for (const anchor of anchors) {
    const dist = from.manhattanDistance(anchor);
    if (dist < min) {
      min = dist;
    }
  }
  return min;
}

/**
 * Reconstruct route by concatenating points with their parents
 * Removes redundant points in the same direction
 */
function reconstructRoute(parents, points, tailPoint, startPoint, endPoint) {
  const route = [];
  let prevDiff = normalizePoint(endPoint.diff(tailPoint));

  // tailPoint is assumed to be aligned already
  let currentKey = getKey(tailPoint);
  let parent = parents.get(currentKey);
  let point;
  while (parent) {
    // point is assumed to be aligned already
    point = points.get(currentKey);
    if (point) {
      const diff = normalizePoint(point.diff(parent));
      if (!diff.equals(prevDiff)) {
        route.unshift(point);
        prevDiff = diff;
      }
    }

    // parent is assumed to be aligned already
    currentKey = getKey(parent);
    parent = parents.get(currentKey);
  }

  // leadPoint is assumed to be aligned already
  const leadPoint = points.get(currentKey);
  if (leadPoint) {
    const fromDiff = normalizePoint(leadPoint.diff(startPoint));
    if (!fromDiff.equals(prevDiff)) {
      route.unshift(leadPoint);
    }
  }
  return route;
}