From f39ac55e47886335d8da0e673d32773f3c37db2e Mon Sep 17 00:00:00 2001
From: Lars Brubaker <larsbrubaker@gmail.com>
Date: Mon, 9 Jul 2018 16:48:12 -0700
Subject: [PATCH] Make cancel work better on ungroup

---
 PartPreviewWindow/CreateDiscreteMeshes.cs | 18 +++++++++++++++++-
 PartPreviewWindow/View3D/SceneActions.cs  | 12 ++++++++++++
 Submodules/agg-sharp                      |  2 +-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/PartPreviewWindow/CreateDiscreteMeshes.cs b/PartPreviewWindow/CreateDiscreteMeshes.cs
index 3029f7fd4..cbfbcea43 100644
--- a/PartPreviewWindow/CreateDiscreteMeshes.cs
+++ b/PartPreviewWindow/CreateDiscreteMeshes.cs
@@ -29,6 +29,7 @@ either expressed or implied, of the FreeBSD Project.
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Threading;
 using ClipperLib;
@@ -50,12 +51,27 @@ namespace MatterHackers.MatterControl
 	{
 		public static List<Mesh> SplitVolumesIntoMeshes(Mesh meshToSplit, CancellationToken cancellationToken, Action<double, string> reportProgress)
 		{
+			Stopwatch maxProgressReport = Stopwatch.StartNew();
 			List<Mesh> discreetVolumes = new List<Mesh>();
 			HashSet<Face> facesThatHaveBeenAdded = new HashSet<Face>();
 			Mesh meshFromCurrentVolume = null;
 			Stack<Face> attachedFaces = new Stack<Face>();
-			for (int faceIndex = 0; faceIndex < meshToSplit.Faces.Count; faceIndex++)
+			int faceCount = meshToSplit.Faces.Count;
+			for (int faceIndex = 0; faceIndex < faceCount; faceIndex++)
 			{
+				if (reportProgress != null)
+				{
+					if (maxProgressReport.ElapsedMilliseconds > 200)
+					{
+						reportProgress(faceIndex / (double)faceCount, "Merging Mesh Edges");
+						maxProgressReport.Restart();
+						if (cancellationToken.IsCancellationRequested)
+						{
+							return null;
+						}
+					}
+				}
+
 				Face currentFace = meshToSplit.Faces[faceIndex];
 				// If this face as not been added to any volume, create a new volume and add all of the attached faces.
 				if (!facesThatHaveBeenAdded.Contains(currentFace))
diff --git a/PartPreviewWindow/View3D/SceneActions.cs b/PartPreviewWindow/View3D/SceneActions.cs
index 2505abb67..e83363c8e 100644
--- a/PartPreviewWindow/View3D/SceneActions.cs
+++ b/PartPreviewWindow/View3D/SceneActions.cs
@@ -97,6 +97,10 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 								progressStatus.Status = processingState;
 								reporter.Report(progressStatus);
 							});
+							if(cancellationToken.IsCancellationRequested)
+							{
+								return Task.CompletedTask;
+							}
 							progressStatus.Status = "Clean".Localize();
 							reporter.Report(progressStatus);
 							ungroupMesh.CleanAndMergeMesh(cancellationToken, 0, (progress0To1, processingState) =>
@@ -105,6 +109,10 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 								progressStatus.Status = processingState;
 								reporter.Report(progressStatus);
 							});
+							if (cancellationToken.IsCancellationRequested)
+							{
+								return Task.CompletedTask;
+							}
 							using (selectedItem.RebuildLock())
 							{
 								selectedItem.Mesh = ungroupMesh;
@@ -118,6 +126,10 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 								progressStatus.Status = processingState;
 								reporter.Report(progressStatus);
 							});
+							if (cancellationToken.IsCancellationRequested)
+							{
+								return Task.CompletedTask;
+							}
 
 							if (discreetMeshes.Count == 1)
 							{
diff --git a/Submodules/agg-sharp b/Submodules/agg-sharp
index 567928b41..3811863d4 160000
--- a/Submodules/agg-sharp
+++ b/Submodules/agg-sharp
@@ -1 +1 @@
-Subproject commit 567928b4170ac786a5db3171edb2db3bc93d62b6
+Subproject commit 3811863d420c25b06784dc0888018b22c8f3fb92