Thanks for your suggestion Hippe013, I will try that out shortly.
First, with regards to the PointMonitor, I simply lifted code from the Devblog, see link below
http://through-the-interface.typepad.com/through_the_interface/2009/07/providing-information-on-auto...
This approach looked cool, but would not actually let me select an item, nor did it drill down into the CorridorFeatureLines
In the meantime, I have successfully managed to pick out a CorridorFeaturelLine from a corridor model. I first allow the user to select a corridor item, then draw a pickbox in screen units using the PICKBOX system variable.
I them enumerate through all CorridorFeatureLines, checking each segment against the new pickbox entities. If there is an intersection, I store the CFL into a new list.
This list is then shown in a new dialog, where the user selects the line they want.
I'm still looking into improving the intersection checking (something like line.IntersectsWith())? , but check out the code below and let me know what you think.
[CommandMethod("FLSelect")]
public void FLSelect()
{
// Have the user select a corridor.
try
{
// Get the AutoCAD Editor
acApp.Document doc = acApp.Application.DocumentManager.MdiActiveDocument;
Editor ed = doc.Editor;
Database acCurDb = doc.Database;
string sPrompt = "Select corridor:";
PromptEntityOptions entOpts = new PromptEntityOptions(sPrompt);
entOpts.Message = sPrompt;
PromptEntityResult entRes = null;
try
{
entRes = ed.GetEntity(entOpts);
}
catch (System.Exception)
{
ed.WriteMessage("You did not select a valid entity\n");
throw;
}
if (entRes.Status == PromptStatus.OK)
{
//Transaction acTrans = acCurDb.TransactionManager.StartTransaction();
FeatureLineInstanceRepository featureLineRepo = new FeatureLineInstanceRepository();
featureLineRepo.ExtractFeatureLines(entRes.ObjectId, acCurDb, ed);
using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
{
// First get the currently selected object
Point3d screenPt = entRes.PickedPoint;
ObjectId objId = entRes.ObjectId;
// Get pickbox's size. Note, the number obtained from
// system variable "PICKBOX" is actually the half of
// pickbox's width/height
object pBox = acApp.Application.GetSystemVariable("PICKBOX");
int pSize = Convert.ToInt32(pBox);
int viewPortNumber = Convert.ToInt32(Autodesk.AutoCAD.ApplicationServices.Application.GetSystemVariable("cvport").ToString());
// Define a Point3dCollection for CrossingWindow selecting
Point3dCollection points = new Point3dCollection();
System.Windows.Point pScreen;
System.Windows.Point p;
Point3d pt;
pScreen = ed.PointToScreen(screenPt, viewPortNumber);
p = new System.Windows.Point(pScreen.X - pSize, pScreen.Y - pSize);
pt = ed.PointToWorld(p, viewPortNumber);
points.Add(pt);
p = new System.Windows.Point(pScreen.X + pSize, pScreen.Y - pSize);
pt = ed.PointToWorld(p, viewPortNumber);
points.Add(pt);
p = new System.Windows.Point(pScreen.X + pSize, pScreen.Y + pSize);
pt = ed.PointToWorld(p, viewPortNumber);
points.Add(pt);
p = new System.Windows.Point(pScreen.X - pSize, pScreen.Y + pSize);
pt = ed.PointToWorld(p, viewPortNumber);
points.Add(pt);
// pickbox cross window lines
Line pickBoxLine1 = new Line(new Point3d(points[0].X, points[0].Y, 0.0),
new Point3d(points[2].X, points[2].Y, 0.0));
Line pickBoxLine2 = new Line(new Point3d(points[1].X, points[1].Y, 0.0),
new Point3d(points[3].X, points[3].Y, 0.0));
// Loop through each item in the feature line list
foreach (FeatureLineInstance item in featureLineRepo.FeatureLineRepository)
{
bool intFound = false;
// Loop through each segment of the featureline
for (int i = 0; i < item.Points.Count - 1; i++)
{
Point3d pt1 = new Point3d(item.Points[i].X, item.Points[i].Y, 0.0);
Point3d pt2 = new Point3d(item.Points[i + 1].X, item.Points[i + 1].Y, 0.0);
Line lineSegment = new Line(pt1, pt2);
PointXYZ ptInt = new PointXYZ();
intFound |= DoLinesIntersect(pickBoxLine1, lineSegment, ref ptInt);
intFound |= DoLinesIntersect(pickBoxLine2, lineSegment, ref ptInt);
if (intFound == true && item.Name != "None")
{
// Add featureline to FeatureLineUnderPickbox
featureLineRepo.FeatureLineUnderPickbox.Add(item);
ed.WriteMessage($"Found String: {item.Name}\n");
break;
}
}
}
// Add the values to a datagridview
if (featureLineRepo.FeatureLineUnderPickbox.Count == 1)
{
ed.WriteMessage("You have selected: " + featureLineRepo.FeatureLineUnderPickbox[0].Name + "\n");
ed.WriteMessage(" and it contains " + featureLineRepo.FeatureLineUnderPickbox[0].Points.Count.ToString() + " point\n");
}
else if (featureLineRepo.FeatureLineUnderPickbox.Count > 1)
{
// create a new form
frmSelectFeatureLine frmSFL = new frmSelectFeatureLine(featureLineRepo.FeatureLineUnderPickbox);
acApp.Application.ShowModalDialog(frmSFL);
}
// You can also use GetPoint and use after Editor.SelectCrossingWindow with a
// small window centered on the point to get the entity
// (but you are not sure to get a single entity).
// To set the size of the window, you can use the PICKBOX system variable. You need to make a conversion pixel->world units.
//The safe way is to use GetEntity to get the entity, then GetPoint to get the break point.
acTrans.Commit();
}
}
}
catch (System.Exception ex)
{
}
}
/// <summary>
/// This is based off an explanation and expanded math presented by Paul Bourke:
///
/// It takes two lines as inputs and returns true if they intersect, false if they
/// don't.
/// If they do, ptIntersection returns the point where the two lines intersect.
/// </summary>
/// <param name="L1">The first line</param>
/// <param name="L2">The second line</param>
/// <param name="ptIntersection">The point where both lines intersect (if they do).</param>
/// <returns></returns>
/// http://paulbourke.net/geometry/lineline2d/
/// http://paulbourke.net/geometry/lineline2d/Helpers.cs
/// <remarks>See http://local.wasp.uwa.edu.au/~pbourke/geometry/lineline2d/</remarks>
public static bool DoLinesIntersect(Line L1, Line L2, ref PointXYZ ptIntersection)
{
// Denominator for ua and ub are the same, so store this calculation
double d =
(L2.EndPoint.Y - L2.StartPoint.Y) * (L1.EndPoint.X - L1.StartPoint.X)
-
(L2.EndPoint.X - L2.StartPoint.X) * (L1.EndPoint.Y - L1.StartPoint.Y);
//n_a and n_b are calculated as seperate values for readability
double n_a =
(L2.EndPoint.X - L2.StartPoint.X) * (L1.StartPoint.Y - L2.StartPoint.Y)
-
(L2.EndPoint.Y - L2.StartPoint.Y) * (L1.StartPoint.X - L2.StartPoint.X);
double n_b =
(L1.EndPoint.X - L1.StartPoint.X) * (L1.StartPoint.Y - L2.StartPoint.Y)
-
(L1.EndPoint.Y - L1.StartPoint.Y ) * (L1.StartPoint.X - L2.StartPoint.X);
// Make sure there is not a division by zero - this also indicates that
// the lines are parallel.
// If n_a and n_b were both equal to zero the lines would be on top of each
// other (coincidental). This check is not done because it is not
// necessary for this implementation (the parallel check accounts for this).
if (d == 0)
return false;
// Calculate the intermediate fractional point that the lines potentially intersect.
double ua = n_a / d;
double ub = n_b / d;
// The fractional point will be between 0 and 1 inclusive if the lines
// intersect. If the fractional calculation is larger than 1 or smaller
// than 0 the lines would need to be longer to intersect.
if (ua >= 0d && ua <= 1d && ub >= 0d && ub <= 1d)
{
ptIntersection.X = L1.StartPoint.X + (ua * (L1.EndPoint.X - L1.StartPoint.X));
ptIntersection.Y = L1.StartPoint.Y + (ua * (L1.EndPoint.Y - L1.StartPoint.Y));
return true;
}
return false;
}
Regards
Andrew Milford
Sr. Product Manager
Autodesk Pty Ltd
100 Commercial St,
Manchester NH 03101
Alumni
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