opencpn-manual-fix.js

// Main Features:
// - Manual fix: Draws a line from a clicked position at a specified bearing and distance, with a distance-dependent multiplier for realism.
//   Optionally, draws a 90-degree arc (distance ring) centered on the bearing axis.
// - Fix: Marks a position with a timestamp and formatted latitude/longitude.
// - Context menu setup: Ensures the custom context menu items are available after each action.
//
// Utility functions:
// - formatLatLon: Formats latitude/longitude in degrees and decimal minutes (DMM) with directional suffixes.
// - setupContextMenu: Registers the context menu items.
//
// Integration:
// - Uses OCPN* API functions for map interaction, route/waypoint creation, and context menu management.
// - Parks the console on script load for debugging.

// Handle updates
version = 1.2;
require("checkForUpdate")("ManualFix", version, 0,"https://gist.githubusercontent.com/SkySails/264c2b51ee567c48ed1087cfd92ccc21/raw/version.json"); // prettier-ignore

// ------------------------------------------------------------------------

const manualFixMenuName = "Manual fix";
OCPNonContextMenu(drawBearing, manualFixMenuName);

var clickedPosition; // The last position to be right-clicked to trigger the context menu

/**
 * Handles the drawing of a bearing from a given location.
 * Opens a dialogue for user input (bearing and range), and sets up a context menu.
 *
 * @param {Object} location - The location object representing the clicked position.
 */
function drawBearing(location) {
  clickedPosition = location;

  onDialogue(handleDialogue, [
    { type: "field", label: "BRG" },
    { type: "field", label: "RNG" },
    { type: "button", label: ["*OK"] },
  ]);

  setupContextMenu();
}

/**
 * Handles the user dialogue input to create a route and optionally a distance ring.
 *
 * - If neither bearing nor distance is provided, does nothing.
 * - Calculates a new position from a clicked position using the provided bearing and distance.
 * - Adds a route (bearing line) from the clicked position to the new position.
 * - If distance is provided, also creates a 90-degree arc (distance ring) centered on the bearing axis.
 * - If only distance is provided, creates a distance ring around the clicked position at the specified distance
 */
function handleDialogue(dialogue) {
  const isBearingProvided = dialogue[0].value && dialogue[0].value.trim() !== "";
  const isDistanceProvided = dialogue[1].value && dialogue[1].value.trim() !== "";

  // No input provided, exit early (do nothing)
  if (!isBearingProvided && !isDistanceProvided) return;

  const bearing = isBearingProvided ? (parseFloat(dialogue[0].value) + 180) % 360 : null;
  const distance = isDistanceProvided ? parseFloat(dialogue[1].value) : null;

  if (isBearingProvided) {
    // Default distance to 50NM if not provided
    const distanceWithFallback = distance || 50;

    // Apply distance multiplier (extending the line to create an intersecting point)
    const vectorLength = distanceWithFallback * getDistanceMultiplier(distanceWithFallback);

    // Calculate the terminal point of the bearing line using the clicked position and a vector (bearing and distance)
    const terminalPoint = OCPNgetPositionPV(clickedPosition, { bearing, distance: vectorLength });

    // Create a route (bearing line) from the clicked position to the new position
    const bearingLine = {
      name: "Bearing vector line",
      isActive: false,
      isVisible: true,
      waypoints: [
        { position: clickedPosition, GUID: OCPNgetNewGUID(), isVisible: true, iconName: "empty" },
        { position: terminalPoint, GUID: OCPNgetNewGUID(), isVisible: true, iconName: "empty" },
      ],
    };

    // Add the bearing line to the map
    OCPNaddRoute(bearingLine);
  }

  if (isDistanceProvided) {
    // Create waypoints for a full circle if no bearing, or 40-degree arc if bearing exists
    const numPoints = bearing === null ? 72 : 19; // 5 degree steps (72 for circle, 19 for arc)
    const arcWaypoints = [];

    // The amount of degrees, in total, to draw when bearing is provided
    const arcDegrees = 90;

    const arcStart = bearing === null ? 0 : bearing - arcDegrees / 2;
    const arcEnd = bearing === null ? 360 : bearing + arcDegrees / 2;

    for (var i = 0; i < numPoints; i++) {
      const angle = arcStart + ((arcEnd - arcStart) * i) / (numPoints - 1);
      const pos = OCPNgetPositionPV(clickedPosition, { bearing: (angle + 360) % 360, distance });
      arcWaypoints.push({
        position: pos,
        markName: "",
        GUID: OCPNgetNewGUID(),
        description: "",
        isVisible: true,
        iconName: "empty",
        iconDescription: "Empty",
        isNameVisible: false,
        isFreeStanding: false,
        isActive: false,
        hyperlinkList: [],
      });
    }

    const distanceRing = {
      name: "Distance ring",
      from: "",
      to: "",
      description: "Distance ring at " + distance + "m",
      isActive: false,
      isVisible: true,
      color: "#eb4034",
      waypoints: arcWaypoints,
    };

    OCPNaddRoute(distanceRing);
  }
}

// ------------------------------------------------------------------------
// "Fix" menu

const fixMenuName = "Fix";
OCPNonContextMenu(drawPositionFix, fixMenuName);

/**
 * Draws a position fix waypoint on the map at the specified location.
 * Formats the latitude and longitude in degrees and decimal minutes (DMM) with directional indicators.
 * The waypoint is labeled with the current time and formatted coordinates.
 *
 * @param {Object} location - The geographic location for the waypoint.
 * @param {number} location.latitude - The latitude of the position.
 * @param {number} location.longitude - The longitude of the position.
 */
function drawPositionFix(location) {
  waypoint = {
    position: location,
    markName: new Date().toTimeString().split(".")[0] + "\n" + formatLatLon(location.latitude, location.longitude),
    isNameVisible: true,
    iconName: "Symbol-X-Large-Black",
  };

  OCPNaddSingleWaypoint(waypoint);
  setupContextMenu();
}

// ------------------------------------------------------------------------
// Utilities

function getDistanceMultiplier(distance) {
  if (distance < 5) {
    return 2;
  } else if (distance > 10) {
    return 1.1;
  } else {
    // Smooth curve between 2 (at 5NM) and 1.1 (at 10NM)
    // Linear interpolation: multiplier = m1 + (m2 - m1) * ((distance - d1) / (d2 - d1))
    const d1 = 5,
      d2 = 10,
      m1 = 2,
      m2 = 1.1;
    return m1 + (m2 - m1) * ((distance - d1) / (d2 - d1));
  }
}

function formatLatLon(lat, lon) {
  function toDMM(deg, isLat) {
    var abs = Math.abs(deg);
    var d = Math.floor(abs);
    var m = ((abs - d) * 60).toFixed(1);
    var dir = isLat ? (deg >= 0 ? "N" : "S") : deg >= 0 ? "E" : "W";
    var degStr;
    if (isLat) {
      degStr = d < 10 ? "0" + d : "" + d;
    } else {
      if (d < 10) degStr = "00" + d;
      else if (d < 100) degStr = "0" + d;
      else degStr = "" + d;
    }
    return degStr + "* " + m + "' " + dir;
  }
  return toDMM(lat, true) + "    " + toDMM(lon, false);
}

function setupContextMenu() {
  OCPNonContextMenu();
  OCPNonContextMenu(drawBearing, manualFixMenuName);
  OCPNonContextMenu(drawPositionFix, fixMenuName);
}

// Park console as soon as script is run
consolePark();

version.json

{
  "name": "ManualFix",
  "version": 1.2,
  "date": "3 Jun 2025",
  "script": "https://gist.githubusercontent.com/SkySails/264c2b51ee567c48ed1087cfd92ccc21/raw/opencpn-manual-fix.js",
  "new": "Added full distance ring visualization when only range is provided as input",
  "pluginVersion": 3.1
}