closestPoint static method

Point closestPoint(PickerGeometry geometry, Point point)

Implementation

static Point closestPoint(PickerGeometry geometry, Point point) {
// In order to find the closest line we use the point's angle
  var angle = Geometry.angleFromOrigin(point);
  var numVertices = geometry.vertices.length;
  var relativeAngle;
  var smallestRelativeAngle = Math.pi * 2;
  var index1 = 0;

  for (int i = 0; i < numVertices; i += 1) {
    relativeAngle = Geometry.normalizeAngle(geometry.angles[i] - angle);
    if (relativeAngle < smallestRelativeAngle) {
      smallestRelativeAngle = relativeAngle;
      index1 = i;
    }
  }

  var index2 = (index1 - 1 + numVertices) % numVertices;
  var closestLine = geometry.lines[index2];

  // Provided point is within the polygon
  if (Geometry.distanceFromOrigin(point) <
      Geometry.lengthOfRayUntilIntersect(angle, closestLine)) {
    return point;
  }

  Line perpendicularLine =
      Geometry.perpendicularThroughPoint(closestLine, point);
  Point intersectionPoint =
      Geometry.intersectLineLine(closestLine, perpendicularLine);

  Point bound1 = geometry.vertices[index1];
  Point bound2 = geometry.vertices[index2];
  Point upperBound;
  Point lowerBound;

  if (bound1.x > bound2.x) {
    upperBound = bound1;
    lowerBound = bound2;
  } else {
    upperBound = bound2;
    lowerBound = bound1;
  }

  var borderPoint;
  if (intersectionPoint.x > upperBound.x) {
    borderPoint = upperBound;
  } else if (intersectionPoint.x < lowerBound.x) {
    borderPoint = lowerBound;
  } else {
    borderPoint = intersectionPoint;
  }

  return borderPoint;
}