Replace HashSet.Contains with bool[] in RemoveTriangles

[Copilot]

RemoveTriangles called HashSet<int>.Contains up to 5 times per triangle across three loops (mapping, compaction, neighbor remap). For ~5 200 triangles that's ~26 000 hash lookups — hash computation + bucket chase on every call.

Change

Build a bool[] isRemoved from the HashSet once up front, then use direct indexed reads everywhere:

var isRemoved = new bool[_trianglesCount];
foreach (int i in removed) isRemoved[i] = true;
// all subsequent removed.Contains(i) → isRemoved[i]

Benchmark delta (Sweden dataset, ShortRun)

Benchmark	Before	After	Δ
EraseSuperTriangle – Auto	2.142 ms	1.934 ms	−9.7%
EraseOuterTriangles – Auto	2.470 ms	2.308 ms	−6.6%
Full pipeline – Auto	2.636 ms	2.561 ms	−2.8%
All others	—	—	within noise

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[github-actions]

Summary

Summary

Generated on:	2/22/2026 - 10:52:36 PM
Coverage date:	2/22/2026 - 10:52:33 PM
Parser:	Cobertura
Assemblies:	1
Classes:	17
Files:	7
Line coverage:	85.1% (1269 of 1490)
Covered lines:	1269
Uncovered lines:	221
Coverable lines:	1490
Total lines:	3731
Branch coverage:	80.1% (619 of 772)
Covered branches:	619
Total branches:	772
Method coverage:	Feature is only available for sponsors
Tag:	61_22287058099

Coverage

CDT.Core - 85.1%

Name	Line	Branch
CDT.Core	85.1%	80.1%
CDT.Box2d`1	73.6%	100%
CDT.CdtUtils	83.1%	72.8%
CDT.CovariantReadOnlyDictionary`3	18.1%	50%
CDT.DictionaryExtensions	100%	100%
CDT.DuplicatesInfo	100%
CDT.DuplicateVertexException	66.6%
CDT.Edge	75%	66.6%
CDT.IntersectingConstraintsException	0%
CDT.KdTree`1	72.7%	65%
CDT.LayerDepth	0%
CDT.Predicates.PredicatesAdaptive	97.6%	91.5%
CDT.Predicates.PredicatesExact	33.7%	100%
CDT.TopologyVerifier	77.2%	63.8%
CDT.Triangle	66.6%	71.4%
CDT.Triangulation`1	93.8%	84.1%
CDT.TriangulationException	100%
CDT.V2d`1	44.4%	25%