[Copilot]

This update brings the applicable upstream changes into CDT.NET, including triangle refinement, conforming-edge robustness fixes, and third-party license attribution.

• Triangle refinement: Add smallest-angle and largest-area criteria, vertex budgets, encroached-edge handling, and reporting for unrefined cases.
• Topology APIs and fixes: Add collection/finalization workflows and winding verification; prevent circumcenters outside the input hull from expanding it.
• Licensing: Attribute the BSD-licensed adaptive predicates and include both license texts in the NuGet package.

cdt.InsertVertices(vertices);
cdt.ConformToEdges(edges);

var toErase = cdt.CollectOuterTrianglesAndHoles();
var unrefined = cdt.RefineTriangles(
    maxVerticesToInsert: 10_000,
    refinementCriterion: RefinementCriterion.SmallestAngle,
    refinementThreshold: CdtUtils.DegToRad(20.0),
    toEraseOrNull: toErase);

cdt.FinalizeTriangulation(toErase);

• Fixes Bulk Update #31

[github-actions]

Summary

Summary

Generated on:	10/29/2026 - 12:38:12 PM
Coverage date:	10/29/2026 - 12:38:09 PM
Parser:	Cobertura
Assemblies:	1
Classes:	20
Files:	8
Line coverage:	87.5% (1763 of 2014)
Covered lines:	1763
Uncovered lines:	251
Coverable lines:	2014
Total lines:	4683
Branch coverage:	84.3% (957 of 1134)
Covered branches:	957
Total branches:	1134
Method coverage:	Feature is only available for sponsors
Tag:	130_40861379781

Coverage

CDT.Core - 87.5%

Name	Line	Branch
CDT.Core	87.5%	84.3%
CDT.Box2d`1	73.6%	100%
CDT.CdtUtils	86.3%	76.5%
CDT.CovariantReadOnlyDictionary`3	18.1%	50%
CDT.DictionaryExtensions	100%	100%
CDT.DuplicatesInfo	100%
CDT.DuplicateVertexException	66.6%
CDT.Edge	83.3%	66.6%
CDT.IntersectingConstraintsException	0%
CDT.InvalidEdgeSplitVertexException	71.4%
CDT.KdTree`1	72.7%	65%
CDT.LayerDepth	0%
CDT.Predicates.PredicatesAdaptive	89.4%	82.1%
CDT.Predicates.PredicatesExact	35.3%	100%
CDT.TopologyVerifier	84.8%	71.7%
CDT.Triangle	66.6%	71.4%
CDT.Triangulation`1	95.6%	89.7%
CDT.TriangulationException	100%
CDT.TriangulationFinalizedException	100%
CDT.Unrefined	50%
CDT.V2d`1	44.4%	25%

[Copilot]

🟡 Changes recommended

Critical active issues remain in smallest-angle calculation, constrained-edge preservation during flips, and safe handling of caller-supplied removal sets, so correctness is not established.

3 open issues

• Use the two longest sides when calculating the smallest angle · New
• Compare all original-edge mappings before constrained edge flips · New
• Validate super-triangle coverage before shifting finalized indices · New

What changed in this PR

This pull request ports upstream CDT refinement, topology, predicate, and licensing updates into CDT.NET.

Changes:

• Adds smallest-angle and largest-area refinement with encroached-edge handling, vertex budgets, and unrefined-case reporting.
• Adds collection/finalization workflows, winding verification, and constrained-edge robustness improvements.
• Adds adaptive predicate attribution, NuGet license packaging, documentation, and regression coverage.

This pull request requires changes.

File	Description
test/​CDT.Tests/​TriangulationTests.cs	Tests winding validation and near-vertex constraint splitting.
test/​CDT.Tests/​RefinementTests.cs	Tests refinement criteria, budgets, hull handling, and failure reporting.
test/​CDT.Tests/​PredicatesTests.cs	Tests strict diametral-circle encroachment behavior.
test/​CDT.Tests/​GroundTruthTests.cs	Extends conforming topology validation with winding checks.
test/​CDT.Tests/​expected/​issue-142-double-hanging-edge__conforming_auto_ignore_auto.txt	Updates expected topology output for revised conforming-edge behavior.
src/​CDT.Core/​Types.cs	Defines refinement criteria and unrefined-result counters.
src/​CDT.Core/​Triangulation.Refinement.cs	Implements triangle refinement and encroached-edge resolution.
src/​CDT.Core/​Triangulation.cs	Adds lifecycle APIs and constrained-topology robustness changes.
src/​CDT.Core/​TopologyVerifier.cs	Adds counter-clockwise winding verification.
src/​CDT.Core/​Predicates/​PredicatesAdaptive.cs	Adds the adaptive diametral-circle predicate and attribution.
src/​CDT.Core/​CdtUtils.cs	Adds geometric helpers for refinement and encroachment detection.
src/​CDT.Core/​CDT.Core.csproj	Updates license metadata and packages both license files.
README.md	Documents refinement support and adaptive-predicate licensing.
LICENSE-predicates.txt	Adds the BSD 3-Clause license for adaptive predicates.

_{Review effort: Lite}