Files
OpenNest/OpenNest.Engine/BestFit/NfpSlideStrategy.cs

101 lines
3.6 KiB
C#

using OpenNest.Geometry;
using System.Collections.Generic;
namespace OpenNest.Engine.BestFit
{
public class NfpSlideStrategy : IBestFitStrategy
{
private readonly double _part2Rotation;
public NfpSlideStrategy(double part2Rotation, int type, string description)
{
_part2Rotation = part2Rotation;
Type = type;
Description = description;
}
public int Type { get; }
public string Description { get; }
public List<PairCandidate> GenerateCandidates(Drawing drawing, double spacing, double stepSize)
{
var candidates = new List<PairCandidate>();
var halfSpacing = spacing / 2;
// Extract stationary polygon (Part1 at rotation 0), with spacing applied.
var stationaryResult = PolygonHelper.ExtractPerimeterPolygon(drawing, halfSpacing);
if (stationaryResult.Polygon == null)
return candidates;
var stationaryPoly = stationaryResult.Polygon;
// Orbiting polygon: same shape rotated to Part2's angle.
var orbitingPoly = PolygonHelper.RotatePolygon(stationaryResult.Polygon, _part2Rotation);
// Compute NFP.
var nfp = NoFitPolygon.Compute(stationaryPoly, orbitingPoly);
if (nfp == null || nfp.Vertices.Count < 3)
return candidates;
// Coordinate correction: NFP offsets are in polygon-space.
// Part.CreateAtOrigin uses program bbox origin.
var correction = stationaryResult.Correction;
// Walk NFP boundary — vertices + edge samples.
var verts = nfp.Vertices;
var vertCount = nfp.IsClosed() ? verts.Count - 1 : verts.Count;
var testNumber = 0;
for (var i = 0; i < vertCount; i++)
{
// Add vertex candidate.
var offset = ApplyCorrection(verts[i], correction);
candidates.Add(MakeCandidate(drawing, offset, spacing, testNumber++));
// Add edge samples for long edges.
var next = (i + 1) % vertCount;
var dx = verts[next].X - verts[i].X;
var dy = verts[next].Y - verts[i].Y;
var edgeLength = System.Math.Sqrt(dx * dx + dy * dy);
if (edgeLength > stepSize)
{
var steps = (int)(edgeLength / stepSize);
for (var s = 1; s < steps; s++)
{
var t = (double)s / steps;
var sample = new Vector(
verts[i].X + dx * t,
verts[i].Y + dy * t);
var sampleOffset = ApplyCorrection(sample, correction);
candidates.Add(MakeCandidate(drawing, sampleOffset, spacing, testNumber++));
}
}
}
return candidates;
}
private static Vector ApplyCorrection(Vector nfpVertex, Vector correction)
{
return new Vector(nfpVertex.X + correction.X, nfpVertex.Y + correction.Y);
}
private PairCandidate MakeCandidate(Drawing drawing, Vector offset, double spacing, int testNumber)
{
return new PairCandidate
{
Drawing = drawing,
Part1Rotation = 0,
Part2Rotation = _part2Rotation,
Part2Offset = offset,
StrategyType = Type,
TestNumber = testNumber,
Spacing = spacing
};
}
}
}