优化点在多段线内部的算法,使算法更健壮,避免圆弧切线问题.

src/DatabaseServices/PointInPolyline.ts

@@ -1,12 +1,9 @@
 import { Vector2, Vector3 } from 'three';
-import { angle, equal, equaln, greater } from '../Geometry/GeUtils';
+import { angle, equaln } from '../Geometry/GeUtils';
 import { IntersectOption } from '../GraphicsSystem/IntersectWith';
 import { Arc } from './Arc';
-import { Circle } from './Circle';
 import { Line } from './Line';
 import { Polyline } from './Polyline';
-import { Contour } from './Contour';
-
 
 /**
  * 点在扇形内部,提供一个简单实现的版本.
@@ -73,33 +70,72 @@ export function IsPointInPolyLine(pl: Polyline, pt: Vector3): boolean
 
     for (let i = 0; i < pl.EndParam; i++)
     {
-        let cu = pl.GetCurveAtIndex(i);
+        if (equaln(pl.GetBuilgeAt(i), 0))//直线
-        let inpts = cu.IntersectWith(insLine, IntersectOption.ExtendArg);
-
-        for (let pti of inpts)
         {
-            if (pti.y < pt.y)
+            let sp = pl.GetPointAtParam(i);
+            let ep = pl.GetPointAtParam(i + 1);
+            //点位于线上面
+            if (pt.y > Math.max(sp.y, ep.y))
+                continue;
+            //线垂直Y轴
+            let derX = ep.x - sp.x;
+            if (equaln(derX, 0))
                 continue;
 
-            if (equal(pti, cu.StartPoint))
+            //起点
+            if (equaln(sp.x, pt.x))
             {
-                let der = cu.GetFistDeriv(0);
+                if (sp.y > pt.y && derX < 0) crossings++;
-                if (equaln(der.x, 0) && cu instanceof Arc)
+                continue;
-                    der = cu.GetFistDeriv(0.1);
-                if (der.x < -1e-4) //左边+ 右边0
-                    crossings++;
             }
-            else if (equal(pti, cu.EndPoint))
+            //终点
+            if (equaln(ep.x, pt.x))
+            {
+                if (ep.y > pt.y && derX > 0) crossings++;
+                continue;
+            }
+
+            //快速求交,只验证有没有交点
+            let [x1, x2] = sp.x > ep.x ? [ep.x, sp.x] : [sp.x, ep.x];
+            if (pt.x > x1 && pt.x < x2)
             {
-                let der = cu.GetFistDeriv(1);
+                let derY = ep.y - sp.y;
-                if (equaln(der.x, 0) && cu instanceof Arc)
+                let k = derY / derX;
-                    der = cu.GetFistDeriv(0.9);
+
-                if (der.x > 1e-4) //左边+ 右边0
+                if ((pt.x - sp.x) * k + sp.y > pt.y)
                     crossings++;
             }
-            else
+        }
+        else //圆弧
+        {
+            let arc = pl.GetCurveAtIndex(i);
+            let sp = arc.StartPoint;
+            let ep = arc.EndPoint;
+
+            //当点和起点或者终点和点相切时
+            if (equaln(sp.x, pt.x) && sp.y > pt.y)
+            {
+                let der = arc.GetFistDeriv(0);
+                if (equaln(der.x, 0))
+                {
+                    if (ep.x - sp.x < 0) crossings++;
+                    continue;
+                }
+            }
+            if (equaln(ep.x, pt.x) && ep.y > pt.y)
+            {
+                let der = arc.GetFistDeriv(1);
+                if (equaln(der.x, 0))
+                {
+                    if (ep.x - sp.x > 0) crossings++;
+                    continue;
+                }
+            }
+            for (let pti of arc.IntersectWith(insLine, IntersectOption.ExtendArg))
             {
-                let der = cu.GetFistDeriv(pti);
+                if (pti.y < pt.y)
+                    continue;
+                let der = arc.GetFistDeriv(pti);
                 if (!equaln(der.x, 0)) //相切.
                     crossings++;
             }