Polygons with holes

[micycle1]

yes it works with holes, they have to defined as a separate loop in a backwards direction

I'm following this but I'm unable to get it to behave with holes. I've tried every combination of exterior & interior coordinates directions. Examples:

No hole

Exterior loop CCW, interior loop (hole) CW

Exterior loop CCW, interior loop CCW

Exterior loop CW, interior loop CCW

Exterior loop CW, interior loop CW

Code

Polygon polygon;
Machine speed = new Machine(1); // every edge same speed
Skeleton skeleton;
LoopL<org.twak.camp.Edge> loopL = new LoopL<>(); // list of loops
ArrayList<Corner> corners = new ArrayList<>();
Loop<org.twak.camp.Edge> loop = new Loop<>();

LinearRing exterior = polygon.getExteriorRing();
if (!Orientation.isCCW(exterior.getCoordinates())) {
	exterior = exterior.reverse(); // exterior should be CCW
}

Coordinate[] coords = exterior.getCoordinates();
for (int j = 0; j < coords.length - 1; j++) {
	double a = coords[j].x;
	double b = coords[j].y;
	corners.add(new Corner(a, b));
}
for (int j = 0; j < corners.size() - 1; j++) {
	org.twak.camp.Edge edge = new org.twak.camp.Edge(corners.get(j),
			corners.get((j + 1) % (corners.size() - 1)));
	edge.machine = speed;
	loop.append(edge);
}
loopL.add(loop);

for (int i = 0; i < polygon.getNumInteriorRing(); i++) {
	corners = new ArrayList<>();
	LinearRing hole = polygon.getInteriorRingN(i);
	if (Orientation.isCCW(hole.getCoordinates())) {
		hole = hole.reverse(); // holes should be clockwise
	}
	for (int j = 0; j < hole.getNumPoints() - 1; j++) {
		corners.add(new Corner(hole.getCoordinates()[j].x, hole.getCoordinates()[j].y));
	}
	loop = new Loop<>();
	for (int j = 0; j < corners.size() - 1; j++) {
		org.twak.camp.Edge edge = new org.twak.camp.Edge(corners.get(j),
				corners.get((j + 1) % (corners.size() - 1)));
		edge.machine = speed;
		loop.append(edge);
	}
	loopL.add(loop);
}

[twak]

Looks like you have negative speeds on the hole?

…

On Sun, Mar 28, 2021 at 10:44 PM Michael Carleton ***@***.***> wrote: yes it works with holes, they have to defined as a separate loop in a backwards direction I'm following this but I'm unable to get it to behave with holes. I've tried every combination of exterior & interior coordinates direction. Examples: No hole [image: image] <https://user-images.githubusercontent.com/9304234/112768914-4cf90300-9016-11eb-8aff-1467786ff710.png> Exterior loop CCW, interior loop CW [image: exCCWinCW] <https://user-images.githubusercontent.com/9304234/112768710-3605e100-9015-11eb-91fa-c9972a1926a5.gif> Exterior loop CCW, interior loop CCW [image: exCCWinCCW] <https://user-images.githubusercontent.com/9304234/112768774-91d06a00-9015-11eb-9ae8-a0ccd8fdd2df.gif> Exterior loop CW, interior loop CCW [image: exCWinCCW] <https://user-images.githubusercontent.com/9304234/112768870-03101d00-9016-11eb-8bf3-13d9ce1cc556.gif> Exterior loop CW, interior loop CW [image: exCWinCW] <https://user-images.githubusercontent.com/9304234/112768900-3783d900-9016-11eb-9d9d-2c2d5251989d.gif> Code Polygon polygon; Skeleton skeleton; LoopL<org.twak.camp.Edge> loopL = new LoopL<>(); // list of loops ArrayList<Corner> corners = new ArrayList<>(); Loop<org.twak.camp.Edge> loop = new Loop<>(); LinearRing exterior = polygon.getExteriorRing(); if (!Orientation.isCCW(exterior.getCoordinates())) { exterior = exterior.reverse(); // exterior should be CCW } Coordinate[] coords = exterior.getCoordinates(); for (int j = 0; j < coords.length - 1; j++) { double a = coords[j].x; double b = coords[j].y; corners.add(new Corner(a, b)); } for (int j = 0; j < corners.size() - 1; j++) { org.twak.camp.Edge edge = new org.twak.camp.Edge(corners.get(j), corners.get((j + 1) % (corners.size() - 1))); edge.machine = speed; loop.append(edge); } loopL.add(loop); for (int i = 0; i < polygon.getNumInteriorRing(); i++) { corners = new ArrayList<>(); LinearRing hole = polygon.getInteriorRingN(i); if (Orientation.isCCW(hole.getCoordinates())) { hole = hole.reverse(); // holes should be clockwise } for (int j = 0; j < hole.getNumPoints() - 1; j++) { corners.add(new Corner(hole.getCoordinates()[j].x, hole.getCoordinates()[j].y)); } loop = new Loop<>(); for (int j = 0; j < corners.size() - 1; j++) { org.twak.camp.Edge edge = new org.twak.camp.Edge(corners.get(j), corners.get((j + 1) % (corners.size() - 1))); edge.machine = speed; loop.append(edge); } loopL.add(loop); } — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#13>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAA7DKQFBHCVEI5EQZXQLFLTF6WMBANCNFSM4Z6OPJ2Q> .

[twak]

Confirmed holes works. Code in WeightedPointEditorWithHoles. Closing.

[micycle1]

I think the problem was that the coordinates weren't closed (didn't have same start and end coordinate) (though I thought this wouldn't be a problem since Edges should connect the shape anyway).