Merge branch 'offset_dir_fix'

src/Add-on/Offset.ts

@@ -74,17 +74,30 @@ export class Command_TestOffset implements Command
                 {
                     if (lastpls) lastpls.forEach(cu => cu.Erase());
 
-                    let ptClose = cu.GetClosestPointTo(p, false);
-                    let toPtVec = p.clone().sub(ptClose);           //点击处向量
-                    let d = cu.GetFistDeriv(cu.GetParamAtPoint(ptClose));//切线。
-                    let c = toPtVec.cross(d);
+                    let dist = p.distanceTo(cu.GetClosestPointTo(p, !cu.IsClose));
 
                     if (cu instanceof Polyline && cu.EndParam > 1 && cu.Area > 0)
                     {
-                        c.z = (IsPointInPolyLine(cu, p) ? -1 : 1) * Math.sign(cu.Area2);
+                        let pls1 = cu.GetOffsetCurves(dist);
+                        let pls2 = cu.GetOffsetCurves(-dist);
+
+                        let dis1 = Math.min.apply(undefined, pls1.map(c => p.distanceTo(c.GetClosestPointTo(p, false))));
+                        let dis2 = Math.min.apply(undefined, pls2.map(c => p.distanceTo(c.GetClosestPointTo(p, false))));
+
+                        if (dis1 < dis2)
+                            lastpls = pls1;
+                        else
+                            lastpls = pls2;
+                    }
+                    else
+                    {
+                        let ptClose = cu.GetClosestPointTo(p, false);
+                        let toPtVec = p.clone().sub(ptClose);           //点击处向量
+                        let d = cu.GetFistDeriv(cu.GetParamAtPoint(ptClose));//切线。
+                        let c = toPtVec.cross(d);
+                        lastpls = cu.GetOffsetCurves(p.distanceTo(cu.GetClosestPointTo(p, !cu.IsClose)) * Math.sign(c.z));
                     }
 
-                    lastpls = cu.GetOffsetCurves(p.distanceTo(cu.GetClosestPointTo(p, !cu.IsClose)) * Math.sign(c.z));
                     lastpls.forEach((offCur) =>
                     {
                         app.m_Database.ModelSpace.Append(offCur);