added ProgressCancel, use to allow cancellation of computation in Red…

…ucer and Remesher

core/ProgressCancel.cs

@@ -0,0 +1,58 @@
+using System;
+
+namespace g3
+{
+    /// <summary>
+    /// interface that provides a cancel function
+    /// </summary>
+    public interface ICancelSource
+    {
+        bool Cancelled();
+    }
+
+
+    /// <summary>
+    /// Just wraps a func<bool> as an ICancelSource
+    /// </summary>
+    public class CancelFunction : ICancelSource
+    {
+        public Func<bool> CancelF;
+        public CancelFunction(Func<bool> cancelF) {
+            CancelF = cancelF;
+        }
+        public bool Cancelled() { return CancelF(); }
+    }
+
+
+    /// <summary>
+    /// This class is intended to be passed to long-running computes to 
+    ///  1) provide progress info back to caller (not implemented yet)
+    ///  2) allow caller to cancel the computation
+    /// </summary>
+    public class ProgressCancel
+    {
+        public ICancelSource Source;
+
+        bool WasCancelled = false;  // will be set to true if CancelF() ever returns true
+
+        public ProgressCancel(ICancelSource source)
+        {
+            Source = source;
+        }
+        public ProgressCancel(Func<bool> cancelF)
+        {
+            Source = new CancelFunction(cancelF);
+        }
+
+        /// <summary>
+        /// Check if client would like to cancel
+        /// </summary>
+        public bool Cancelled()
+        {
+            if (WasCancelled)
+                return true;
+            WasCancelled = Source.Cancelled();
+            return WasCancelled;
+        }
+    }
+}

geometry3Sharp.csproj

@@ -78,6 +78,7 @@
     <Compile Include="core\Units.cs" />
     <Compile Include="core\DVectorArray.cs" />
     <Compile Include="core\VectorArray.cs" />
+    <Compile Include="core\ProgressCancel.cs" />
     <Compile Include="curve\BaseCurve2.cs" />
     <Compile Include="curve\BSplineBasis.cs" />
     <Compile Include="curve\Circle2.cs" />

mesh/MeshRefinerBase.cs

@@ -50,6 +50,19 @@ public void SetExternalConstraints(MeshConstraints cons)
         }
 
 
+        /// <summary>
+        /// Set this to be able to cancel running remesher
+        /// </summary>
+        public ProgressCancel Progress = null;
+
+        /// <summary>
+        /// if this returns true, abort computation. 
+        /// </summary>
+        protected virtual bool Cancelled() {
+            return (Progress == null) ? false : Progress.Cancelled();
+        }
+
+
         protected double edge_flip_metric(ref Vector3d n0, ref Vector3d n1)
         {
             if (edge_flip_tol == 0) {

mesh/Reducer.cs

@@ -81,8 +81,14 @@ public virtual void DoReduce()
 
             begin_setup();
             Precompute();
+            if (Cancelled())
+                return;
             InitializeVertexQuadrics();
+            if (Cancelled())
+                return;
             InitializeQueue();
+            if (Cancelled())
+                return;
             end_setup();
 
             begin_ops();
@@ -103,6 +109,8 @@ public virtual void DoReduce()
                 int eid = EdgeQueue.Dequeue();
                 if (!mesh.IsEdge(eid))
                     continue;
+                if (Cancelled())
+                    return;
 
                 int vKept;
                 ProcessResult result = CollapseEdge(eid, EdgeQuadrics[eid].collapse_pt, out vKept);
@@ -114,6 +122,9 @@ public virtual void DoReduce()
             end_collapse();
             end_ops();
 
+            if (Cancelled())
+                return;
+
             Reproject();
 
             end_pass();
@@ -170,6 +181,8 @@ public virtual void FastCollapsePass(double fMinEdgeLength)
 
             begin_setup();
             Precompute();
+            if (Cancelled())
+                return;
             end_setup();
 
             begin_ops();
@@ -183,6 +196,8 @@ public virtual void FastCollapsePass(double fMinEdgeLength)
                     continue;
                 if (mesh.IsBoundaryEdge(eid))
                     continue;
+                if (Cancelled())
+                    return;
 
                 mesh.GetEdgeV(eid, ref va, ref vb);
                 if (va.DistanceSquared(ref vb) > min_sqr)
@@ -200,6 +215,9 @@ public virtual void FastCollapsePass(double fMinEdgeLength)
             end_collapse();
             end_ops();
 
+            if (Cancelled())
+                return;
+
             Reproject();
 
             end_pass();

mesh/Remesher.cs

@@ -171,10 +171,15 @@ public virtual void BasicRemeshPass() {
                     if (result == ProcessResult.Ok_Collapsed || result == ProcessResult.Ok_Flipped || result == ProcessResult.Ok_Split)
                         ModifiedEdgesLastPass++;
                 }
+                if (Cancelled())        // expensive to check every iter?
+                    return;
                 cur_eid = next_edge(cur_eid, out done);
             } while (done == false);
             end_ops();
 
+            if (Cancelled())
+                return;
+
             begin_smooth();
             if (EnableSmoothing && SmoothSpeedT > 0) {
                 if (EnableSmoothInPlace)
@@ -185,13 +190,19 @@ public virtual void BasicRemeshPass() {
             }
             end_smooth();
 
+            if (Cancelled())
+                return;
+
             begin_project();
             if (target != null && ProjectionMode == TargetProjectionMode.AfterRefinement) {
                 FullProjectionPass();
                 DoDebugChecks();
             }
             end_project();
 
+            if (Cancelled())
+                return;
+
             end_pass();
 		}