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perf: use perimeter-only drawing in best fit pair evaluation

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PairEvaluator was cloning the full CNC program (including all internal
cutouts) for every candidate. For parts with many holes (e.g. 952),
this caused O(n²) overlap checks and thousands of unnecessary polygon
tessellations per candidate.

Now extracts the perimeter shape once, builds a lightweight drawing
from it, and uses that for all Part.CreateAtOrigin calls. Cutouts are
irrelevant for best fit — only the outer boundary matters for pairing.

75x speedup on a 952-hole rectangle (30s → 0.4s).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
AJ Isaacs
2026-04-09 12:14:02 -04:00
parent 640814fdf6
commit 3481764416
1 changed files with 35 additions and 33 deletions
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68
OpenNest.Engine/BestFit/PairEvaluator.cs
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@@ -15,11 +15,18 @@ namespace OpenNest.Engine.BestFit
public List<BestFitResult> EvaluateAll(List<PairCandidate> candidates)
{
if (candidates.Count == 0)
return new List<BestFitResult>();
// Build a perimeter-only drawing once — all candidates share the same drawing.
// This avoids cloning the full program (with all cutouts) for every candidate.
var perimeterDrawing = CreatePerimeterDrawing(candidates[0].Drawing);
var resultBag = new ConcurrentBag<BestFitResult>();
Parallel.ForEach(candidates, c =>
{
resultBag.Add(Evaluate(c));
resultBag.Add(Evaluate(c, perimeterDrawing));
});
return resultBag.ToList();
@@ -27,18 +34,24 @@ namespace OpenNest.Engine.BestFit
public BestFitResult Evaluate(PairCandidate candidate)
{
var drawing = candidate.Drawing;
var perimeterDrawing = CreatePerimeterDrawing(candidate.Drawing);
return Evaluate(candidate, perimeterDrawing);
}
var part1 = Part.CreateAtOrigin(drawing);
private BestFitResult Evaluate(PairCandidate candidate, Drawing perimeterDrawing)
{
var part1 = Part.CreateAtOrigin(perimeterDrawing);
var part2 = Part.CreateAtOrigin(drawing, candidate.Part2Rotation);
var part2 = Part.CreateAtOrigin(perimeterDrawing, candidate.Part2Rotation);
part2.Location = candidate.Part2Offset;
part2.UpdateBounds();
// Check overlap via shape intersection
var overlaps = CheckOverlap(part1, part2);
// Overlap check — perimeter vs perimeter
var shape1 = GetPerimeterShape(part1);
var shape2 = GetPerimeterShape(part2);
var overlaps = shape1 != null && shape2 != null && shape1.Intersects(shape2, out _);
// Collect all polygon vertices for convex hull / optimal rotation
// Convex hull vertices from perimeter polygons only
var allPoints = GetPartVertices(part1);
allPoints.AddRange(GetPartVertices(part2));
@@ -66,7 +79,7 @@ namespace OpenNest.Engine.BestFit
hullAngles = new List<double> { 0 };
}
var trueArea = drawing.Area * 2;
var trueArea = candidate.Drawing.Area * 2;
// Normalize to landscape (width >= height) for consistent display.
if (bestHeight > bestWidth)
@@ -91,38 +104,29 @@ namespace OpenNest.Engine.BestFit
};
}
private bool CheckOverlap(Part part1, Part part2)
private static Drawing CreatePerimeterDrawing(Drawing source)
{
var shapes1 = GetPartShapes(part1);
var shapes2 = GetPartShapes(part2);
for (var i = 0; i < shapes1.Count; i++)
{
for (var j = 0; j < shapes2.Count; j++)
{
List<Vector> pts;
if (shapes1[i].Intersects(shapes2[j], out pts))
return true;
}
}
return false;
var entities = ConvertProgram.ToGeometry(source.Program)
.Where(e => e.Layer != SpecialLayers.Rapid).ToList();
var profile = new ShapeProfile(entities);
var program = ConvertGeometry.ToProgram(profile.Perimeter);
return new Drawing(source.Name, program);
}
private List<Shape> GetPartShapes(Part part)
private static Shape GetPerimeterShape(Part part)
{
var entities = ConvertProgram.ToGeometry(part.Program)
.Where(e => e.Layer != SpecialLayers.Rapid);
.Where(e => e.Layer != SpecialLayers.Rapid).ToList();
var shapes = ShapeBuilder.GetShapes(entities);
shapes.ForEach(s => s.Offset(part.Location));
return shapes;
if (shapes.Count == 0) return null;
shapes[0].Offset(part.Location);
return shapes[0];
}
private List<Vector> GetPartVertices(Part part)
private static List<Vector> GetPartVertices(Part part)
{
var entities = ConvertProgram.ToGeometry(part.Program)
.Where(e => e.Layer != SpecialLayers.Rapid);
.Where(e => e.Layer != SpecialLayers.Rapid).ToList();
var shapes = ShapeBuilder.GetShapes(entities);
var points = new List<Vector>();
@@ -130,9 +134,7 @@ namespace OpenNest.Engine.BestFit
{
var polygon = shape.ToPolygonWithTolerance(ChordTolerance);
polygon.Offset(part.Location);
foreach (var vertex in polygon.Vertices)
points.Add(vertex);
points.AddRange(polygon.Vertices);
}
return points;