避免多段线偏移多余的合并

src/DatabaseServices/Curve.ts

@@ -127,6 +127,12 @@ export abstract class Curve extends Entity
         return equalv3(this.StartPoint, pt, 1e-12) || equalv3(this.EndPoint, pt, 1e-12) || this.ParamOnCurve(this.GetParamAtPoint(pt));
     }
 
+    //点在曲线中,不在起点或者终点.
+    PtOnCurve2(pt: Vector3): boolean
+    {
+        return !(equalv3(this.StartPoint, pt, 1e-12) || equalv3(this.EndPoint, pt, 1e-12)) && this.ParamOnCurve(this.GetParamAtPoint(pt), 0);
+    }
+
     //参数在曲线上 容差,1e-12
     ParamOnCurve(param: number, fuzz = 1e-12): boolean { return !isNaN(param) && param >= -fuzz && param <= this.EndParam + fuzz; }
     GetOffsetCurves(offsetDist: number): Array<Curve> { return; }

src/GraphicsSystem/OffsetPolyline.ts

@@ -126,13 +126,16 @@ export class PolyOffsetUtil
                 if (c2b.min.y - 1e-6 > c1b.max.y)
                     continue;
 
-                if (c1.Join(c2) === Status.True)
-                {
-                    this.m_RetCurves.splice(j, 1);
-                    c1b = c1.BoundingBox;
-                    boxCurves.set(c1, c1b);
-                    j--;
-                }
+                //有共线部分才允许合并.
+                if (c2.PtOnCurve2(c1.StartPoint) || c2.PtOnCurve2(c1.EndPoint)
+                    || c1.PtOnCurve2(c2.StartPoint) || c1.PtOnCurve2(c2.EndPoint))
+                    if (c1.Join(c2) === Status.True)
+                    {
+                        this.m_RetCurves.splice(j, 1);
+                        c1b = c1.BoundingBox;
+                        boxCurves.set(c1, c1b);
+                        j--;
+                    }
             }
         }
     }