Files
OpenNest/OpenNest.IO/TitleBlockDetector.cs
T

313 lines
12 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using ACadSharp;
using OpenNest.Geometry;
namespace OpenNest.IO
{
public static class TitleBlockDetector
{
private static readonly HashSet<string> TitleBlockLayerNames = new(StringComparer.OrdinalIgnoreCase)
{
"TITLE", "TITLEBLOCK", "TITLE_BLOCK", "BORDER", "FRAME",
"TB", "INFO", "SHEET", "ANNOTATION"
};
public static HashSet<Guid> Detect(List<Entity> entities, CadDocument document)
{
var flagged = new HashSet<Guid>();
DetectByLayerName(entities, flagged);
DetectBorder(entities, flagged);
if (document != null)
DetectTitleBlockRegion(entities, document, flagged);
return flagged;
}
private static void DetectByLayerName(List<Entity> entities, HashSet<Guid> flagged)
{
foreach (var entity in entities)
{
if (entity.Layer?.Name != null && TitleBlockLayerNames.Contains(entity.Layer.Name))
flagged.Add(entity.Id);
}
}
private static void DetectBorder(List<Entity> entities, HashSet<Guid> flagged)
{
var lines = entities.OfType<Line>().Where(l => !flagged.Contains(l.Id)).ToList();
if (lines.Count < 4) return;
var bounds = entities.GetBoundingBox();
if (bounds == null || bounds.Area() < OpenNest.Math.Tolerance.Epsilon) return;
var borderCount = 0;
foreach (var line in lines)
{
if (IsBorderLine(line, bounds))
{
flagged.Add(line.Id);
borderCount++;
}
}
if (borderCount >= 2)
DetectZoneMarkers(lines, bounds, flagged);
}
private static bool IsBorderLine(Line line, Box bounds)
{
var dx = line.EndPoint.X - line.StartPoint.X;
var dy = line.EndPoint.Y - line.StartPoint.Y;
var length = System.Math.Sqrt(dx * dx + dy * dy);
var angleRad = System.Math.Atan2(System.Math.Abs(dy), System.Math.Abs(dx));
var angularTolerance = OpenNest.Math.Angle.ToRadians(2.0);
var positionTolerance = System.Math.Max(bounds.Length, bounds.Width) * 0.01;
var isHorizontal = angleRad < angularTolerance;
var isVertical = System.Math.Abs(angleRad - System.Math.PI / 2) < angularTolerance;
if (!isHorizontal && !isVertical) return false;
var minSpan = isHorizontal ? bounds.Length * 0.8 : bounds.Width * 0.8;
if (length < minSpan) return false;
if (isHorizontal)
{
var midY = (line.StartPoint.Y + line.EndPoint.Y) / 2;
return System.Math.Abs(midY - bounds.Bottom) < positionTolerance
|| System.Math.Abs(midY - bounds.Top) < positionTolerance;
}
else
{
var midX = (line.StartPoint.X + line.EndPoint.X) / 2;
return System.Math.Abs(midX - bounds.Left) < positionTolerance
|| System.Math.Abs(midX - bounds.Right) < positionTolerance;
}
}
private static void DetectZoneMarkers(List<Line> lines, Box bounds, HashSet<Guid> flagged)
{
var positionTolerance = System.Math.Max(bounds.Length, bounds.Width) * 0.01;
var maxTickLength = System.Math.Max(bounds.Length, bounds.Width) * 0.05;
var angularTolerance = OpenNest.Math.Angle.ToRadians(2.0);
foreach (var line in lines)
{
if (flagged.Contains(line.Id)) continue;
var dx = line.EndPoint.X - line.StartPoint.X;
var dy = line.EndPoint.Y - line.StartPoint.Y;
var length = System.Math.Sqrt(dx * dx + dy * dy);
if (length > maxTickLength || length < OpenNest.Math.Tolerance.Epsilon) continue;
var angleRad = System.Math.Atan2(System.Math.Abs(dy), System.Math.Abs(dx));
var isVertical = System.Math.Abs(angleRad - System.Math.PI / 2) < angularTolerance;
var isHorizontal = angleRad < angularTolerance;
if (!isVertical && !isHorizontal) continue;
var touchesEdge = false;
if (isVertical)
{
var minY = System.Math.Min(line.StartPoint.Y, line.EndPoint.Y);
var maxY = System.Math.Max(line.StartPoint.Y, line.EndPoint.Y);
touchesEdge = System.Math.Abs(minY - bounds.Bottom) < positionTolerance
|| System.Math.Abs(maxY - bounds.Top) < positionTolerance;
}
else if (isHorizontal)
{
var minX = System.Math.Min(line.StartPoint.X, line.EndPoint.X);
var maxX = System.Math.Max(line.StartPoint.X, line.EndPoint.X);
touchesEdge = System.Math.Abs(minX - bounds.Left) < positionTolerance
|| System.Math.Abs(maxX - bounds.Right) < positionTolerance;
}
if (touchesEdge)
flagged.Add(line.Id);
}
}
private static void DetectTitleBlockRegion(List<Entity> entities, CadDocument document, HashSet<Guid> flagged)
{
var textPositions = ExtractTextPositions(document);
if (textPositions.Count < 3) return;
var unflagged = entities.Where(e => !flagged.Contains(e.Id)).ToList();
if (unflagged.Count == 0) return;
var bounds = entities.GetBoundingBox();
if (bounds == null || bounds.Area() < OpenNest.Math.Tolerance.Epsilon) return;
var bestRegion = FindBestTitleBlockRegion(bounds, textPositions, unflagged);
if (bestRegion == null) return;
var initiallyInside = unflagged.Where(e => {
var c = EntityCenter(e);
return c.HasValue && RegionContains(bestRegion, c.Value);
}).ToList();
var expandedBounds = initiallyInside.Count > 0 ? initiallyInside.GetBoundingBox() : null;
foreach (var entity in unflagged)
{
var center = EntityCenter(entity);
if (!center.HasValue) continue;
if (RegionContains(bestRegion, center.Value)
|| (expandedBounds != null && RegionContains(expandedBounds, center.Value)))
flagged.Add(entity.Id);
}
}
private static List<Vector> ExtractTextPositions(CadDocument document)
{
var positions = new List<Vector>();
foreach (var entity in document.Entities)
{
switch (entity)
{
case ACadSharp.Entities.MText mtext:
positions.Add(new Vector(mtext.InsertPoint.X, mtext.InsertPoint.Y));
break;
case ACadSharp.Entities.TextEntity text:
var pt = text.HorizontalAlignment != 0 || text.VerticalAlignment != 0
? text.AlignmentPoint : text.InsertPoint;
positions.Add(new Vector(pt.X, pt.Y));
break;
}
}
return positions;
}
private static Box FindBestTitleBlockRegion(Box bounds, List<Vector> textPositions, List<Entity> entities)
{
var candidates = GenerateCandidateRegions(bounds);
Box bestRegion = null;
var bestScore = 0.0;
var openLines = FindOpenLines(entities);
foreach (var region in candidates)
{
var textCount = textPositions.Count(p => RegionContains(region, p));
if (textCount < 3) continue;
var openLineCount = openLines.Count(l => RegionContains(region, l.MidPoint));
var area = region.Area();
if (area < OpenNest.Math.Tolerance.Epsilon) continue;
var score = (double)textCount + openLineCount * 0.5;
var regionCenterX = (region.Left + region.Right) / 2;
var regionCenterY = (region.Bottom + region.Top) / 2;
if (regionCenterX > bounds.Center.X) score *= 1.3;
if (regionCenterY < bounds.Center.Y) score *= 1.3;
if (score > bestScore)
{
bestScore = score;
bestRegion = region;
}
}
return bestRegion;
}
private static List<Box> GenerateCandidateRegions(Box bounds)
{
var regions = new List<Box>();
var fractions = new[] { 0.25, 0.333, 0.5 };
foreach (var fx in fractions)
{
foreach (var fy in fractions)
{
var w = bounds.Length * fx;
var h = bounds.Width * fy;
regions.Add(new Box(bounds.Right - w, bounds.Bottom, w, h));
regions.Add(new Box(bounds.Left, bounds.Bottom, w, h));
regions.Add(new Box(bounds.Right - w, bounds.Top - h, w, h));
regions.Add(new Box(bounds.Left, bounds.Top - h, w, h));
}
}
foreach (var fy in fractions)
{
var h = bounds.Width * fy;
regions.Add(new Box(bounds.Left, bounds.Bottom, bounds.Length, h));
}
foreach (var fx in fractions)
{
var w = bounds.Length * fx;
regions.Add(new Box(bounds.Right - w, bounds.Bottom, w, bounds.Width));
}
return regions;
}
private static List<Line> FindOpenLines(List<Entity> entities)
{
var endpointUsers = new Dictionary<long, int>();
foreach (var entity in entities)
{
foreach (var ep in GetEntityEndpoints(entity))
{
var key = QuantizePoint(ep);
endpointUsers[key] = endpointUsers.GetValueOrDefault(key) + 1;
}
}
var openLines = new List<Line>();
foreach (var line in entities.OfType<Line>())
{
var startKey = QuantizePoint(line.StartPoint);
var endKey = QuantizePoint(line.EndPoint);
if (endpointUsers.GetValueOrDefault(startKey) <= 1 || endpointUsers.GetValueOrDefault(endKey) <= 1)
openLines.Add(line);
}
return openLines;
}
private static List<Vector> GetEntityEndpoints(Entity entity)
{
return entity switch
{
Line line => new List<Vector> { line.StartPoint, line.EndPoint },
Arc arc => new List<Vector> { arc.StartPoint(), arc.EndPoint() },
_ => new List<Vector>()
};
}
private static long QuantizePoint(Vector pt)
{
var qx = (long)(pt.X * 1000);
var qy = (long)(pt.Y * 1000);
return qx * 100000000L + qy;
}
private static Vector? EntityCenter(Entity entity)
{
return entity switch
{
Line line => line.MidPoint,
Arc arc => arc.Center,
Circle circle => circle.Center,
_ => null
};
}
private static bool RegionContains(Box box, Vector pt)
{
return pt.X >= box.Left && pt.X <= box.Right
&& pt.Y >= box.Bottom && pt.Y <= box.Top;
}
}
}