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Questions tagged [clipperlib]

Polygon and line clipping and offsetting library (C++, C#, Delphi)

56 questions
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Have Clipper Merge Polygon's (with hole) into One instead of Two Polygons

I am merging a number of polygon's using the clipper library and am having one main issue. When a polygon exists with a hole in it, I would like one single closed path to represent the polygon including the hole. What the tool is giving me is two…
Maria
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ClipperLib Clip multiple squares with rectangle produces 1 result

I'm using v6.4.2 of the C# version of the ClipperLib. I have a lot of squares making up a fishnet. I also have a rectangle. I want to get a result where only the squares that are inside the rectangle are returned and partially overlapped get…
Paul Meems
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Line and Polygon clipping returns empty Paths using Clipper library (c++)

I am trying to split a polygon by a line using the Clipper library. After the execution of clipping, it returns empty path. Can someone suggest the right way to do the same. Paths clip(2),soln; clip[0] << IntPoint(-264,-210) <<…
saitej
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How do I determine if two polygons intersect using Clipper?

I am using Clipper and want to determine if two (multi-)polygons intersect. My expectation was that the library would have a nice, abstract way of asking this question, but it does not seem to. I thought that the Area() method might be useful, but…
Richard
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Clipping Open Paths in Clipper Library

In Clipper, given an open path (black) and a closed polygon (blue), how can I clip the open path such that the clipped parts get completed using the polygon contours and, when possible, a single path remains instead of disjoint segments? What…
Adi Shavit
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Spikes when offsetting with C# clipper

I am getting quite a few spikes when offsetting Polygons with the clipper library, this is unfortunately not acceptable in my use case and I have no idea how to get rid of it. I have tried all type of join type settings but could not achieve…
Gerharddc
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How clip works in polygon union in Clipper library

I use clipper library. In the figure, red and black are clips and and green are polygons. The code is listed below. However, I do not understand why the resulting union polygon is (7 3 4 14 9 1 2 6). I assume it should be (1 4 14 9)? The number is…
Sean
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Clip hollow polygons using the clipper library

I wrote the following function according to the usage of the clipper library, but the printed result is not the coordinates of the clipped polygon I want。I want to know where the main problem of this code is, or that the clipper library cannot give…
start all over again
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What is the meaning of open path "orientation" in clipperlib?

ClipperLib documentation about offset operation says among preconditions: The orientations of closed paths must be consistent such that outer polygons share the same orientation, and any holes have the opposite orientation (ie non-zero filling).…
6502
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Is that possible to give floating values to the clipper Paths

Clipper takes integer input but I want to pass floating values without losing the precision. Clipper struct for Integer and double value. struct IntPoint { cInt X; cInt Y; #ifdef use_xyz cInt Z; IntPoint(cInt x = 0, cInt y = 0, cInt z = 0):…
AravindK
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Intersection between line and Polygon using clipper library

I tried all the possibilities. But I am not getting an intersection point between line and polygon. Paths clip(1), soln , pol(1); clip[0] << IntPoint(1,1) << IntPoint(30,30) ; pol[0] << IntPoint(10,10) << IntPoint(20, 10) << IntPoint(20,20) <<…
AravindK
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Pyclipper/Clipper: Intersection of Polylines with Polygon Edge

If I want to clip the intersections between evenly spaced Polylines and a closed rectangle Polygon, the outermost Polylines coincide with the edges of the Rectangle. Polylines Intersection with Rectangle Polygon(Green: Clip, Black: Subject, Red:…
Christoph Breuning
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Concentric offset on polygon

I am using the Angus Johnson's Clipper Library in .NET/C# and I would like to do several concentric offset on a Polygon with the ClipperOffset class.…
lebanese03
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Confused on Clipper in C#

I'm creating a 2D game in Unity which has procedurally placed tiles. I want to simplify the collision geometry using Angus Johnson's Clipper library (specifically the union function), but I'm running into an issue with the library returning empty…
GReusch
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Clipper: Crashing When Clipping Open Polygons

I am trying to use Clipper, an open source polygon clipping library, to clip an open polygon with a closed polygon. I am using the python wrapper of pyclipper. My code is as follows: import pyclipper subj = [[-10, 5], [20, 5]] clip = [[0, 0], [0,…
Adam C
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