aj/OpenNest
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

feat: improve BLF with Clipper paths, spatial pruning, and progress

Browse Source 
Refactor BLF to compute NFP paths as Clipper PathsD with offsets
instead of translating full polygons. Add spatial pruning to skip
NFPs that don't intersect the IFP bounds. Clamp placement points
to IFP bounds to correct Clipper2 floating-point drift. Add
progress reporting to simulated annealing. Add debug logging.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
AJ Isaacs
2026-03-20 14:43:04 -04:00
parent 9411dd0fdd
commit d9d275b675
2 changed files with 91 additions and 66 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
OpenNest.Engine/Nfp/SimulatedAnnealing.cs
View File

@@ -20,11 +20,12 @@ namespace OpenNest.Engine.Nfp
public OptimizationResult Optimize(List<NestItem> items, Box workArea, NfpCache cache,
Dictionary<int, List<double>> candidateRotations,
IProgress<NestProgress> progress = null,
CancellationToken cancellation = default)
{
var random = new Random();
// Build initial sequence: expand NestItems into individual (drawingId, rotation, drawing) entries,
// Build initial sequence: expand NestItems into individual entries,
// sorted by area descending.
var sequence = BuildInitialSequence(items, candidateRotations);
@@ -35,9 +36,9 @@ namespace OpenNest.Engine.Nfp
var blf = new BottomLeftFill(workArea, cache);
var bestPlaced = blf.Fill(sequence);
var bestScore = FillScore.Compute(BottomLeftFill.ToNestParts(bestPlaced), workArea);
var bestSequence = new List<(int, double, Drawing)>(sequence);
var bestSequence = new List<SequenceEntry>(sequence);
var currentSequence = new List<(int, double, Drawing)>(sequence);
var currentSequence = new List<SequenceEntry>(sequence);
var currentScore = bestScore;
// Calibrate initial temperature so ~80% of worse moves are accepted.
@@ -49,13 +50,16 @@ namespace OpenNest.Engine.Nfp
Debug.WriteLine($"[SA] Initial: {bestScore.Count} parts, density={bestScore.Density:P1}, temp={initialTemp:F2}");
ReportBest(progress, BottomLeftFill.ToNestParts(bestPlaced), workArea,
$"NFP: initial {bestScore.Count} parts, density={bestScore.Density:P1}");
while (temperature > DefaultMinTemperature
&& noImprovement < DefaultMaxNoImprovement
&& !cancellation.IsCancellationRequested)
{
iteration++;
var candidate = new List<(int drawingId, double rotation, Drawing drawing)>(currentSequence);
var candidate = new List<SequenceEntry>(currentSequence);
Mutate(candidate, candidateRotations, random);
var candidatePlaced = blf.Fill(candidate);
@@ -72,10 +76,13 @@ namespace OpenNest.Engine.Nfp
if (currentScore > bestScore)
{
bestScore = currentScore;
bestSequence = new List<(int, double, Drawing)>(currentSequence);
bestSequence = new List<SequenceEntry>(currentSequence);
noImprovement = 0;
Debug.WriteLine($"[SA] New best at iter {iteration}: {bestScore.Count} parts, density={bestScore.Density:P1}");
ReportBest(progress, BottomLeftFill.ToNestParts(candidatePlaced), workArea,
$"NFP: iter {iteration}, {bestScore.Count} parts, density={bestScore.Density:P1}");
}
else
{
@@ -118,10 +125,10 @@ namespace OpenNest.Engine.Nfp
/// Builds the initial placement sequence sorted by drawing area descending.
/// Each NestItem is expanded by its quantity.
/// </summary>
private static List<(int drawingId, double rotation, Drawing drawing)> BuildInitialSequence(
private static List<SequenceEntry> BuildInitialSequence(
List<NestItem> items, Dictionary<int, List<double>> candidateRotations)
{
var sequence = new List<(int drawingId, double rotation, Drawing drawing)>();
var sequence = new List<SequenceEntry>();
// Sort items by area descending.
var sorted = items.OrderByDescending(i => i.Drawing.Area).ToList();
@@ -135,7 +142,7 @@ namespace OpenNest.Engine.Nfp
rotation = rotations[0];
for (var i = 0; i < qty; i++)
sequence.Add((item.Drawing.Id, rotation, item.Drawing));
sequence.Add(new SequenceEntry(item.Drawing.Id, rotation, item.Drawing));
}
return sequence;
@@ -144,7 +151,7 @@ namespace OpenNest.Engine.Nfp
/// <summary>
/// Applies a random mutation to the sequence.
/// </summary>
private static void Mutate(List<(int drawingId, double rotation, Drawing drawing)> sequence,
private static void Mutate(List<SequenceEntry> sequence,
Dictionary<int, List<double>> candidateRotations, Random random)
{
if (sequence.Count < 2)
@@ -169,7 +176,7 @@ namespace OpenNest.Engine.Nfp
/// <summary>
/// Swaps two random parts in the sequence.
/// </summary>
private static void MutateSwap(List<(int, double, Drawing)> sequence, Random random)
private static void MutateSwap(List<SequenceEntry> sequence, Random random)
{
var i = random.Next(sequence.Count);
var j = random.Next(sequence.Count);
@@ -183,23 +190,23 @@ namespace OpenNest.Engine.Nfp
/// <summary>
/// Changes a random part's rotation to another candidate angle.
/// </summary>
private static void MutateRotate(List<(int drawingId, double rotation, Drawing drawing)> sequence,
private static void MutateRotate(List<SequenceEntry> sequence,
Dictionary<int, List<double>> candidateRotations, Random random)
{
var idx = random.Next(sequence.Count);
var entry = sequence[idx];
if (!candidateRotations.TryGetValue(entry.drawingId, out var rotations) || rotations.Count <= 1)
if (!candidateRotations.TryGetValue(entry.DrawingId, out var rotations) || rotations.Count <= 1)
return;
var newRotation = rotations[random.Next(rotations.Count)];
sequence[idx] = (entry.drawingId, newRotation, entry.drawing);
sequence[idx] = entry.WithRotation(newRotation);
}
/// <summary>
/// Reverses a random contiguous subsequence.
/// </summary>
private static void MutateReverse(List<(int, double, Drawing)> sequence, Random random)
private static void MutateReverse(List<SequenceEntry> sequence, Random random)
{
var i = random.Next(sequence.Count);
var j = random.Next(sequence.Count);
@@ -221,7 +228,7 @@ namespace OpenNest.Engine.Nfp
/// are accepted initially.
/// </summary>
private static double CalibrateTemperature(
List<(int drawingId, double rotation, Drawing drawing)> sequence,
List<SequenceEntry> sequence,
Box workArea, NfpCache cache,
Dictionary<int, List<double>> candidateRotations, Random random)
{
@@ -234,7 +241,7 @@ namespace OpenNest.Engine.Nfp
for (var i = 0; i < samples; i++)
{
var candidate = new List<(int, double, Drawing)>(sequence);
var candidate = new List<SequenceEntry>(sequence);
Mutate(candidate, candidateRotations, random);
var placed = blf.Fill(candidate);
@@ -266,5 +273,12 @@ namespace OpenNest.Engine.Nfp
return countDiff * 10.0 + densityDiff;
}
private static void ReportBest(IProgress<NestProgress> progress, List<Part> parts,
Box workArea, string description)
{
NestEngineBase.ReportProgress(progress, NestPhase.Nfp, 0, parts, workArea,
description, isOverallBest: true);
}
}
}