refactor: extract shared ArcFit utilities from SplineConverter and GeometrySimplifier

Move identical FitWithStartTangent and MaxRadialDeviation methods
to a shared ArcFit class, eliminating 40-line duplicate.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-03-28 16:11:47 -04:00
parent a85213a524
commit 912a47c5e8
3 changed files with 84 additions and 108 deletions

View File

@@ -437,47 +437,8 @@ public class GeometrySimplifier
/// the arc passes through both endpoints and departs P1 in the given direction.
/// </summary>
private static (Vector center, double radius, double deviation) FitWithStartTangent(
List<Vector> points, Vector tangent)
{
if (points.Count < 3)
return (Vector.Invalid, 0, double.MaxValue);
var p1 = points[0];
var pn = points[^1];
var mx = (p1.X + pn.X) / 2;
var my = (p1.Y + pn.Y) / 2;
var dx = pn.X - p1.X;
var dy = pn.Y - p1.Y;
var chordLen = System.Math.Sqrt(dx * dx + dy * dy);
if (chordLen < 1e-10)
return (Vector.Invalid, 0, double.MaxValue);
var bx = -dy / chordLen;
var by = dx / chordLen;
var tLen = System.Math.Sqrt(tangent.X * tangent.X + tangent.Y * tangent.Y);
if (tLen < 1e-10)
return (Vector.Invalid, 0, double.MaxValue);
var nx = -tangent.Y / tLen;
var ny = tangent.X / tLen;
var det = nx * by - ny * bx;
if (System.Math.Abs(det) < 1e-10)
return (Vector.Invalid, 0, double.MaxValue);
var t = ((mx - p1.X) * by - (my - p1.Y) * bx) / det;
var cx = p1.X + t * nx;
var cy = p1.Y + t * ny;
var radius = System.Math.Sqrt((cx - p1.X) * (cx - p1.X) + (cy - p1.Y) * (cy - p1.Y));
if (radius < 1e-10)
return (Vector.Invalid, 0, double.MaxValue);
return (new Vector(cx, cy), radius, MaxRadialDeviation(points, cx, cy, radius));
}
List<Vector> points, Vector tangent) =>
ArcFit.FitWithStartTangent(points, tangent);
/// <summary>
/// Computes the tangent direction at the last point of a fitted arc,
@@ -629,19 +590,8 @@ public class GeometrySimplifier
/// <summary>
/// Max deviation of intermediate points (excluding endpoints) from a circle.
/// </summary>
private static double MaxRadialDeviation(List<Vector> points, double cx, double cy, double radius)
{
var maxDev = 0.0;
for (var i = 1; i < points.Count - 1; i++)
{
var px = points[i].X - cx;
var py = points[i].Y - cy;
var dist = System.Math.Sqrt(px * px + py * py);
var dev = System.Math.Abs(dist - radius);
if (dev > maxDev) maxDev = dev;
}
return maxDev;
}
private static double MaxRadialDeviation(List<Vector> points, double cx, double cy, double radius) =>
ArcFit.MaxRadialDeviation(points, cx, cy, radius);
/// <summary>
/// Measures the maximum distance from sampled points along the fitted arc