/// <summary>
/// Returns ordered Lists of perimeter edges from a Mesh.
/// There is no guarantee of directionality, only spatially sequential lines.
/// </summary>
/// <returns>
/// A List of Lines.
/// </returns>
public static List <List <Line> > EdgesPerimeters(this Mesh mesh)
{
var edges = new List <Line>();
mesh.Triangles.ToList().ForEach(t => edges.AddRange(t.Edges()));
var pEdges = edges.Where(e => e.Occurs(edges) == 1).ToList();
var perimeters = new List <List <Line> >();
while (pEdges.Count() > 0)
{
var edge = pEdges.First();
pEdges = pEdges.Skip(1).ToList();
var perimeter = new List <Line> {
edge
};
var connected = pEdges.Where(e => e.Start.IsAlmostEqualTo(edge.End) || e.End.IsAlmostEqualTo(edge.End)).ToList();
while (connected.Count() > 0)
{
pEdges.Remove(connected.First());
edge = new Line(edge.End, edge.End.FarthestFrom(connected.First().Points()));
perimeter.Add(edge);
connected = pEdges.Where(e => e.Start.IsAlmostEqualTo(edge.End) || e.End.IsAlmostEqualTo(edge.End)).ToList();
}
perimeters.Add(perimeter);
}
if (perimeters.Count == 1)
{
return(perimeters);
}
return(perimeters.OrderByDescending(p => Shaper.TotalLength(p)).ToList());
}
/// <summary>
/// Returns the perpendicular distance from this Line to the supplied Vector3 point.
/// </summary>
/// <param name="point">Vector3 representing a point.</param>
/// <returns>A double.</returns>
public static double PerpendicularDistanceTo(this Line line, Vector3 point)
{
if (line.PointOnLine(point, true))
{
return(0.0);
}
var area = Math.Abs(Shaper.MakePolygon(new[] { line.Start, line.End, point }.ToList()).Area());
return(area / (line.Length() * 0.5));
}
/// <summary>
/// Returns a new Polygon rotated around a supplied Vector3 by the specified angle in degrees.
/// </summary>
/// <param name="pivot">The Vector3 base point of the rotation.</param>
/// <param name="angle">The desired rotation angle in degrees.</param>
/// <returns>
/// A new Polygon.
/// </returns>
public static Polygon Rotate(this Polygon polygon, Vector3 pivot, double angle)
{
var theta = angle * (Math.PI / 180);
var vertices = new List <Vector3>();
foreach (Vector3 vertex in polygon.Vertices)
{
var rX = (Math.Cos(theta) * (vertex.X - pivot.X)) - (Math.Sin(theta) * (vertex.Y - pivot.Y)) + pivot.X;
var rY = (Math.Sin(theta) * (vertex.X - pivot.X)) + (Math.Cos(theta) * (vertex.Y - pivot.Y)) + pivot.Y;
var rZ = vertex.Z;
vertices.Add(new Vector3(rX, rY, rZ));
}
return(Shaper.MakePolygon(vertices));
}
/// <summary>
/// Returns the List of Polygons that can merge with this Polygon.
/// </summary>
/// <param name="polygons">List of Polygons to test.</param>
/// <returns>A List of Polygons that can be merged with this Polygon.</returns>
public static List <Polygon> CanMerge(this Polygon polygon, List <Polygon> polygons)
{
var mrgPolygons = new List <Polygon>();
foreach (var poly in polygons)
{
var polys = polygon.ToList();
polys.Add(poly);
if (Shaper.Merge(polys).Count == 1)
{
mrgPolygons.Add(poly);
}
}
return(mrgPolygons);
}
/// <summary>
/// Attempts to scale up a Polygon until coming within the tolerance percentage of the target area.
/// </summary>
/// <param name="polygon">Polygon to scale.</param>
/// <param name="area">Target area of the Polygon.</param>
/// <param name="tolerance">Area total tolerance.</param>
/// <param name="origin">Alignment location for final Polygon.</param>
/// <param name="within">Polygon acting as a constraining outer boundary.</param>
/// <param name="among">List of Polygons to avoid intersecting.</param>
/// <returns>
/// A new Polygon.
/// </returns>
public static Polygon ExpandToArea(this Polygon polygon, double area, double ratio,
double tolerance = 0.1, Orient origin = Orient.C,
Polygon within = null, List <Polygon> among = null)
{
if (polygon.IsClockWise())
{
polygon = polygon.Reversed();
}
if (Math.Abs(polygon.Area() - area) <= Math.Abs(tolerance * area))
{
return(polygon);
}
var position = polygon.Compass().PointBy(origin);
Polygon tryPoly = Shaper.RectangleByArea(area, ratio);
tryPoly = tryPoly.MoveFromTo(tryPoly.Compass().PointBy(origin), position);
double tryArea = tryPoly.Area();
do
{
var t = new Transform();
t.Scale(tryArea / area, tryPoly.Compass().PointBy(origin));
tryPoly = tryPoly.TransformedPolygon(t);
if (within != null && tryPoly.Intersects(within))
{
var tryPolys = within.Intersection(tryPoly);
if (tryPolys != null && tryPolys.Count > 0)
{
tryPoly = tryPolys.First();
}
}
if (among != null && tryPoly.Intersects(among))
{
var tryPolys = Shaper.Differences(tryPoly.ToList(), among);
if (tryPolys != null && tryPolys.Count > 0)
{
tryPoly = tryPolys.First();
}
}
tryArea = tryPoly.Area();
}while (!Shaper.NearEqual(tryPoly.Area(), area, tolerance * area) &&
!Shaper.NearEqual(tryPoly.Area(), tryArea, tolerance));
return(tryPoly);
}
/// <summary>
/// Creates the largest Polygon fitted to supplied intersecting Polygons.
/// </summary>
/// <param name="among">List of Polygons against which this Polygon must conform.</param>
/// <returns>
/// A new Polygon.
/// </returns>
public static Polygon FitAmong(this Polygon polygon, List <Polygon> among)
{
if (among == null || among.Count == 0)
{
return(polygon);
}
var polygons = Shaper.Differences(polygon.ToList(), among);
if (polygons.Count == 0)
{
return(null);
}
polygon = polygons.OrderByDescending(p => Math.Abs(p.Area())).First();
if (polygon.IsClockWise())
{
return(polygon.Reversed());
}
return(polygon);
}
/// <summary>
/// Creates a new CCW Polygon of the same vertices with the start point now at the indexed Polygon vertex.
/// </summary>
/// <param name="start">The index of the point from which to start the new Polygon.</param>
/// <returns>A new Polygon.</returns>
public static Polygon RewindFrom(this Polygon polygon, int start)
{
var vertices = polygon.Vertices;
if (start < 0 || start > vertices.Count - 1)
{
return(null);
}
var points = new List <Vector3>()
{
vertices[start]
};
var i = start + 1;
while (i < vertices.Count)
{
points.Add(vertices[i % vertices.Count]);
i++;
}
return(Shaper.MakePolygon(points));
}
/// <summary>
/// Returns a List of Polygons derived from the Polygon's straight skeleton.
/// </summary>
/// <returns>A List of Polygons.</Line></returns>
public static List <Polygon> Jigsaw(this Polygon polygon)
{
var vertices2d = new List <Vector2d>();
foreach (var vertex in polygon.Vertices)
{
vertices2d.Add(new Vector2d(vertex.X, vertex.Y));
}
var skeleton = SkeletonBuilder.Build(vertices2d);
var polygons = new List <Polygon>();
foreach (var edgeResult in skeleton.Edges)
{
var vertices = new List <Vector3>();
foreach (var vertex in edgeResult.Polygon)
{
vertices.Add(new Vector3(vertex.X, vertex.Y, 0.0));
}
polygons.Add(Shaper.MakePolygon(vertices));
}
return(polygons.OrderBy(p => p.Centroid()).ToList());
}
/// <summary>
/// Creates a Polygon with a reduced quantity of points tested against a deviation tolerance.
/// </summary>
/// <param name="tolerance">The deviation tolerance for inclusion in the final Vector3 List.</param>
/// <returns>
/// A new Polygon.
/// </returns>
public static Polygon Straighten(this Polygon polygon, double tolerance)
{
return(Shaper.MakePolygon(SimplifyNet.Straighten(polygon.Vertices.ToList(), tolerance)));
}
/// <summary>
/// Reduces Polygon vertices.
/// </summary>
/// <param name="tolerance">The tolerated deviation to include a vertex.</param>
/// <returns>A new Polyline.</returns>
public static Polygon Simplify(this Polygon polygon, double minLength, double filletFactor = 1.0)
{
return(Shaper.MakePolygon(Shaper.Simplify(polygon.Vertices.ToList(), minLength, filletFactor)));
}
/// <summary>
/// Reduces Polyline vertices.
/// </summary>
/// <param name="minLength">The tolerated deviation to include a vertex.</param>
/// <returns>A new Polyline.</returns>
public static Polyline Simplify(this Polyline polyline, double minLength, double filletFactor = 1.0)
{
return(new Polyline(Shaper.Simplify(polyline.Vertices.ToList(), minLength, filletFactor)));
}
/// <summary>
/// Creates a rotated 2D grid of Vector3 points from the supplied Polygon, axis intervals, and angle.
/// </summary>
/// <param name="perimeter">Polygon boundary of the point grid.</param>
/// <param name="xInterval">Spacing of the grid along the x-axis.</param>
/// <param name="yInterval">Spacing of the grid along the y-axis.</param>
/// <param name="angle">Rotation of the grid around the Polygon centroid.</param>
/// <returns>
/// A new CoordGrid.
/// </returns>
public CoordinateGrid(Polygon polygon, double xInterval = 1.0, double yInterval = 1.0, double angle = 0.0)
{
if (polygon == null)
{
return;
}
random = new Random();
Allocated = new List <Vector3>();
Available = new List <Vector3>();
Perimeter = Shaper.MakePolygon(polygon.Vertices.ToList());
var centroid = polygon.Centroid();
var box = new CompassBox(polygon);
var points = new List <Vector3>();
// Northeast quadrant
var x = centroid.X + (xInterval * 0.5);
var y = centroid.Y + (yInterval * 0.5);
while (y <= box.NW.Y)
{
while (x <= box.SE.X)
{
points.Add(new Vector3(x, y));
x += xInterval;
}
x = centroid.X + (xInterval * 0.5);
y += yInterval;
}
// Northwest quadrant
x = centroid.X - (xInterval * 0.5);
y = centroid.Y + (yInterval * 0.5);
while (y <= box.NW.Y)
{
while (x >= box.SW.X)
{
points.Add(new Vector3(x, y));
x -= xInterval;
}
x = centroid.X - (xInterval * 0.5);
y += yInterval;
}
// Southeast quadrant
x = centroid.X + (xInterval * 0.5);
y = centroid.Y - (yInterval * 0.5);
while (y >= box.SW.Y)
{
while (x <= box.SE.X)
{
points.Add(new Vector3(x, y));
x += xInterval;
}
x = centroid.X + (xInterval * 0.5);
y -= yInterval;
}
// Southwest quadrant
x = centroid.X - (xInterval * 0.5);
y = centroid.Y - (yInterval * 0.5);
while (y >= box.SW.Y)
{
while (x >= box.SW.X)
{
points.Add(new Vector3(x, y));
x -= xInterval;
}
x = centroid.X - (xInterval * 0.5);
y -= yInterval;
}
foreach (var pnt in points)
{
var point = pnt.Rotate(centroid, angle);
if (polygon.Covers(point))
{
Available.Add(point);
}
}
}
/// <summary>
/// Returns a List of Lines representing the Arc divided into the specified quantity of segments.
/// </summary>
/// <param name="segments">Quantity of desired segments.</param>
/// <returns>
/// A List of Lines.
/// </returns>
public static List <Line> ToLines(this Arc arc, int segments)
{
return(Shaper.PointsToLines(arc.Divide(segments)));
}
