Writing custom Hatch pattern

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Writing custom Hatch pattern

Termitt

4/3/2008 7:21 PM

Hi all, i have problem writing DXF with Hatch-Custom Pattern. When I use Pattern = null (not set), then DXF can be displayed in ACAD. But when I try to use custom Pattern, then DXF writing fails. Sometimes with 'OutOfMemory Exception':

C# Code:

at System.Collections.Generic.List`1..ctor(Int32 capacity) at -.|.-(Polyline3D[] borders, Point2D reference, Vector2D offset, Vector2D direction, Double flatness, Double[] dashes, Boolean fillInterior) at -.|.-(Polyline3D[] borders, Point2D reference, Vector2D offset, Vector2D direction, Double flatness, Double[] dashPattern, Boolean fillInterior) at -.|.-(Polyline3D[] borders, Point2D reference, Vector2D offset, Vector2D direction, Double flatness, Double[] dashPattern, Boolean fillInterior) at WW.Cad.Model.Entities.DxfPattern.Line.-(Polyline3D[] boundaries, Point2D seed, Boolean fillInterior) at WW.Cad.Model.Entities.DxfPattern.-(List`1 polylines, Polyline3D[] boundaries, Point2D seed, Boolean fillInterior) at WW.Cad.Model.Entities.DxfHatch.-(Wireframe context) at WW.Cad.Model.Entities.DxfHatch.-(Wireframe context) at WW.Cad.Model.Entities.DxfHatch.DrawInternal(Wireframe context) at WW.Cad.Model.Entities.DxfEntity.Draw(Wireframe context) at WW.Cad.Model.DxfModel.Draw(Wireframe context)

According to TaskManager I have only about 540MB memory used of 2GB... I use this to setup the Hatch pattern.

C# Code:

DxfPattern pat = new DxfPattern(); pat.Lines.Add(new DxfPattern.Line()); pat.Lines[0].Offset = new Vector2D(5d,5d); pat.Lines[0].Angle = Math.PI * 0.25;

Most probably I set something wrong, but I have been trying ot whole day and I'm desperate. If anyone could help me, it would be great. thanks, Termitt

Wout

4/4/2008 12:38 AM

Hi Termitt, I think the problem is that you chose the pattern line's offset vector having the same angle as the pattern angle. The vector must at least have a component perpendicular to the pattern angle otherwise no hatching will happen ofcourse, the hatch line will just continue to be on the same line. Here's a working example (but see also the DxfHatch documentation contains a working example):

C# Code:

using System; using System.Collections.Generic; using System.Drawing; using System.Drawing.Printing; using System.IO; using System.Text; using WW.Cad.Base; using WW.Cad.Drawing; using WW.Cad.Drawing.GDI; using WW.Cad.IO; using WW.Cad.Model; using WW.Cad.Model.Entities; using WW.Cad.Model.Tables; using WW.Cad.Test; using WW.Math; namespace ConsoleApplication { class Program { static void Main(string[] args) { DxfModel model = new DxfModel(); DxfHatch hatch = new DxfHatch(); DxfPattern pat = new DxfPattern(); pat.Lines.Add(new DxfPattern.Line()); pat.Lines[0].DashLengths.AddRange(new double[] { 0.1d, -0.15d, 0d, -0.15d }); pat.Lines[0].Offset = new Vector2D(-0.15d, 0.15d); pat.Lines[0].Angle = Math.PI * 0.25; hatch.Pattern = pat; DxfHatch.BoundaryPath boundaryPath = new DxfHatch.BoundaryPath(); boundaryPath.Type = BoundaryPathType.Polyline; boundaryPath.PolylineData = new DxfHatch.BoundaryPath.Polyline( new Point2D(0d, 0d), new Point2D(1d, 1d), new Point2D(0.5d, 2d), new Point2D(-0.5d, 2d), new Point2D(-1d, 1d) ); boundaryPath.PolylineData.Closed = true; hatch.BoundaryPaths.Add(boundaryPath); hatch.Color = Color.Blue; model.Entities.Add(hatch); DxfWriter.WriteDxf('hatchtest.dxf', model); } } }

Thanks, Wout

Termitt 4/4/2008 9:27 PM
Hi Wout, now it works, great. I know about example in documentation, I have read it several times, but i never realized that i made a mistake in Offset direction ; ). Thank you for help, Termitt Reply

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