/// <summary>
/// Create a collection of profiles from a collection of polygons. Inner polygons will be treated as voids in alternating fashion.
/// </summary>
/// <param name="polygons">The polygons to sort into profiles</param>
/// <param name="tolerance">An optional tolerance.</param>
/// <returns></returns>
public static List <Profile> CreateFromPolygons(IEnumerable <Polygon> polygons, double tolerance = Vector3.EPSILON)
{
Clipper clipper = new Clipper();
foreach (var polygon in polygons)
{
var clipperPath = polygon.ToClipperPath(tolerance);
clipper.AddPath(clipperPath, PolyType.ptSubject, true);
}
PolyTree solution = new PolyTree();
clipper.Execute(ClipType.ctUnion, solution, PolyFillType.pftEvenOdd);
var joinedProfiles = solution.ToProfiles(tolerance);
return(joinedProfiles);
}
/// <summary>
/// Split a set of profiles with a collection of open polylines, with an optional gap between results.
/// </summary>
/// <param name="profiles">The profiles to split</param>
/// <param name="splitLines">The polylines defining the splits.</param>
/// <param name="gapSize">An optional gap size between split pieces. If splits are failing, it can be helpful to increase this.</param>
/// <param name="tolerance">An optional tolerance.</param>
public static List <Profile> Split(IEnumerable <Profile> profiles, IEnumerable <Polyline> splitLines, double gapSize = 0, double tolerance = Vector3.EPSILON)
{
// We're doing something a little bit questionable here — we're offsetting the split curves by a hair's width
// so that clipper can handle them as a subtraction, since it doesn't have a built-in split mechanism.
// We increase the tolerance so that the result is well within the specified tolerance of the expected result.
// This is imperfect, but no more imperfect than all of the other clipper-based operations we currently employ.
var internalTolerance = tolerance / 10; // to keep splits within tolerance, we execute clipper at a 10x smaller tolerance.
Clipper clipper = new Clipper();
foreach (var profile in profiles)
{
var clipperPaths = profile.ToClipperPaths(internalTolerance);
clipper.AddPaths(clipperPaths, PolyType.ptSubject, true);
}
foreach (var line in splitLines)
{
var unionClipper = new Clipper();
// This is basically the same as
// line.Offset(offsetDist, EndType.Butt, internalTolerance),
// but without the unneccessary conversion back to Elements geometry.
var co = new ClipperOffset();
var offsetSolution = new List <List <IntPoint> >();
var offsetPath = line.ToClipperPath(internalTolerance);
var offsetDist = (internalTolerance) + gapSize;
var clipperScale = 1.0 / internalTolerance;
co.AddPath(offsetPath, JoinType.jtMiter, ClipperLib.EndType.etOpenButt);
co.Execute(ref offsetSolution, offsetDist * clipperScale);
List <List <IntPoint> > unionSolution = new List <List <IntPoint> >();
unionClipper.AddPaths(offsetSolution, PolyType.ptSubject, true);
unionClipper.Execute(ClipType.ctUnion, unionSolution, PolyFillType.pftNonZero);
clipper.AddPaths(unionSolution, PolyType.ptClip, true);
}
PolyTree solution = new PolyTree();
clipper.Execute(ClipType.ctDifference, solution, PolyFillType.pftNonZero);
var joinedProfiles = solution.ToProfiles(internalTolerance);
return(joinedProfiles);
}
/// <summary>
/// Constructs the intersections between two sets of profiles.
/// </summary>
/// <param name="firstSet">The first set of profiles to intersect with.</param>
/// <param name="secondSet">The second set of profiles to intersect with.</param>
/// <param name="tolerance">An optional tolerance.</param>
/// <returns>A new list of profiles comprising the overlap between the first set and the second set.</returns>
public static List <Profile> Intersection(IEnumerable <Profile> firstSet, IEnumerable <Profile> secondSet, double tolerance = Vector3.EPSILON)
{
Clipper clipper = new Clipper();
foreach (var profile in firstSet)
{
var clipperPaths = profile.ToClipperPaths(tolerance);
clipper.AddPaths(clipperPaths, PolyType.ptSubject, true);
}
foreach (var profile in secondSet)
{
var clipperPaths = profile.ToClipperPaths(tolerance);
clipper.AddPaths(clipperPaths, PolyType.ptClip, true);
}
PolyTree solution = new PolyTree();
clipper.Execute(ClipType.ctIntersection, solution, PolyFillType.pftNonZero);
var joinedProfiles = solution.ToProfiles(tolerance);
return(joinedProfiles);
}
/// <summary>
/// Perform a union operation on a set of multiple profiles.
/// </summary>
/// <param name="profiles">The profiles with which to create a union.</param>
/// <param name="tolerance">An optional tolerance.</param>
/// <returns>A new list of profiles comprising the union of all input profiles.</returns>
public static List <Profile> UnionAll(IEnumerable <Profile> profiles, double tolerance = Vector3.EPSILON)
{
Clipper clipper = new Clipper();
foreach (var profile in profiles)
{
var subjectPolygons = new List <Polygon> {
profile.Perimeter
};
if (profile.Voids != null && profile.Voids.Count > 0)
{
subjectPolygons.AddRange(profile.Voids);
}
var clipperPaths = subjectPolygons.Select(s => s.ToClipperPath(tolerance)).ToList();
clipper.AddPaths(clipperPaths, PolyType.ptSubject, true);
}
PolyTree solution = new PolyTree();
clipper.Execute(ClipType.ctUnion, solution, PolyFillType.pftPositive);
var joinedProfiles = solution.ToProfiles(tolerance);
return(joinedProfiles);
}
/// <summary>
/// Offset profiles by a given distance.
/// </summary>
/// <param name="profiles">The profiles to offset.</param>
/// <param name="distance">The offset distance.</param>
/// <param name="tolerance">An optional tolerance.</param>
/// <returns>A collection of resulting profiles.</returns>
public static List <Profile> Offset(IEnumerable <Profile> profiles, double distance, double tolerance = Vector3.EPSILON)
{
var clipperScale = 1.0 / tolerance;
ClipperOffset clipper = new ClipperOffset();
foreach (var profile in profiles)
{
var subjectPolygons = new List <Polygon> {
profile.Perimeter
};
if (profile.Voids != null && profile.Voids.Count > 0)
{
subjectPolygons.AddRange(profile.Voids);
}
var clipperPaths = subjectPolygons.Select(s => s.ToClipperPath(tolerance)).ToList();
clipper.AddPaths(clipperPaths, JoinType.jtMiter, ClipperLib.EndType.etClosedPolygon);
}
PolyTree solution = new PolyTree();
clipper.Execute(ref solution, distance * clipperScale);
var joinedProfiles = solution.ToProfiles(tolerance);
return(joinedProfiles);
}
