From 77423153e3dc0c7b87fe5f7ecac592d3b61c8996 Mon Sep 17 00:00:00 2001
From: artem-ogre <artem.ogre@gmail.com>
Date: Mon, 21 Aug 2023 11:16:19 +0200
Subject: [PATCH] #7 Refactor vertex encroaching on edge

---
 CDT/include/CDTUtils.h        |  7 +++++++
 CDT/include/CDTUtils.hpp      | 15 +++++++++++++++
 CDT/include/Triangulation.h   |  2 --
 CDT/include/Triangulation.hpp | 31 ++++++++++---------------------
 4 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/CDT/include/CDTUtils.h b/CDT/include/CDTUtils.h
index 8d594e4b..3452f46e 100644
--- a/CDT/include/CDTUtils.h
+++ b/CDT/include/CDTUtils.h
@@ -427,6 +427,13 @@ CDT_EXPORT T distance(const V2d<T>& a, const V2d<T>& b);
 template <typename T>
 CDT_EXPORT T distanceSquared(const V2d<T>& a, const V2d<T>& b);
 
+/// Check if vertex V is encroaching on diametral circle of an edge
+template <typename T>
+CDT_EXPORT bool isEncroachingOnEdge(
+    const V2d<T>& v,
+    const V2d<T>& edgeStart,
+    const V2d<T>& edgeEnd);
+
 } // namespace CDT
 
 #ifndef CDT_USE_AS_COMPILED_LIBRARY
diff --git a/CDT/include/CDTUtils.hpp b/CDT/include/CDTUtils.hpp
index 2d58bb1c..f068cac8 100644
--- a/CDT/include/CDTUtils.hpp
+++ b/CDT/include/CDTUtils.hpp
@@ -300,4 +300,19 @@ T distanceSquared(const V2d<T>& a, const V2d<T>& b)
     return distanceSquared(a.x, a.y, b.x, b.y);
 }
 
+template <typename T>
+bool isEncroachingOnEdge(
+    const V2d<T>& v,
+    const V2d<T>& edgeStart,
+    const V2d<T>& edgeEnd)
+{
+    /*
+     * Contains a point in its diametral circle:
+     * the angle between v and edge end points is obtuse
+     */
+    return (edgeStart.x - v.x) * (edgeEnd.x - v.x) +
+               (edgeStart.y - v.y) * (edgeEnd.y - v.y) <=
+           T(0);
+}
+
 } // namespace CDT
diff --git a/CDT/include/Triangulation.h b/CDT/include/Triangulation.h
index 9e96e67c..3911abe5 100644
--- a/CDT/include/Triangulation.h
+++ b/CDT/include/Triangulation.h
@@ -521,8 +521,6 @@ class CDT_EXPORT Triangulation
         VertInd iV3,
         VertInd iV4) const;
     TriInd edgeTriangle(Edge edge) const;
-    /// Checks if edge e is encroached by vertex v
-    bool isEncroached(const V2d<T>& v, Edge e) const;
     bool isBadTriangle(
         const Triangle& tri,
         RefineTriangles::Enum refinement,
diff --git a/CDT/include/Triangulation.hpp b/CDT/include/Triangulation.hpp
index 1c4a0b70..3f08e30f 100644
--- a/CDT/include/Triangulation.hpp
+++ b/CDT/include/Triangulation.hpp
@@ -1285,22 +1285,6 @@ TriInd Triangulation<T, TNearPointLocator>::edgeTriangle(const Edge edge) const
     return iT;
 }
 
-/*
- * Contains a point in its diametral circle
- * same as checking if the angle between v and edge end points is obtuse
- */
-template <typename T, typename TNearPointLocator>
-bool Triangulation<T, TNearPointLocator>::isEncroached(
-    const V2d<T>& v,
-    const Edge edge) const
-{
-    const V2d<T> v1 =
-        V2d<T>::make(vertices[edge.v1()].x - v.x, vertices[edge.v1()].y - v.y);
-    const V2d<T> v2 =
-        V2d<T>::make(vertices[edge.v2()].x - v.x, vertices[edge.v2()].y - v.y);
-    return (v1.x * v2.x + v1.y * v2.y) < T(0);
-}
-
 template <typename T, typename TNearPointLocator>
 bool Triangulation<T, TNearPointLocator>::isBadTriangle(
     const Triangle& tri,
@@ -1385,7 +1369,10 @@ EdgeQue Triangulation<T, TNearPointLocator>::detectEncroachedEdges()
         const Triangle& tOpo = triangles[iTopo];
         VertInd v1 = opposedVertex(t, iTopo);
         VertInd v2 = opposedVertex(tOpo, iT);
-        if(isEncroached(vertices[v1], edge) || isEncroached(vertices[v2], edge))
+        const V2d<T>& edgeStart = vertices[edge.v1()];
+        const V2d<T>& edgeEnd = vertices[edge.v2()];
+        if(isEncroachingOnEdge(vertices[v1], edgeStart, edgeEnd) ||
+           isEncroachingOnEdge(vertices[v2], edgeStart, edgeEnd))
         {
             encroachedEdges.push(edge);
         }
@@ -1406,7 +1393,7 @@ Triangulation<T, TNearPointLocator>::detectEncroachedEdges(const V2d<T>& v)
         ++cit)
     {
         const Edge edge = *cit;
-        if(isEncroached(v, edge))
+        if(isEncroachingOnEdge(v, vertices[edge.v1()], vertices[edge.v2()]))
         {
             encroachedEdges.push(edge);
         }
@@ -1462,9 +1449,11 @@ Triangulation<T, TNearPointLocator>::resolveEncroachedEdges(
                 const Triangle& tOpo = triangles[iTopo];
                 VertInd v1 = opposedVertex(t, iTopo);
                 VertInd v2 = opposedVertex(tOpo, iT);
-                if(isEncroached(vertices[v1], edge) ||
-                   isEncroached(vertices[v2], edge) ||
-                   (validV && isEncroached(v, edge)))
+                const V2d<T>& edgeStart = vertices[edge.v1()];
+                const V2d<T>& edgeEnd = vertices[edge.v2()];
+                if(isEncroachingOnEdge(vertices[v1], edgeStart, edgeEnd) ||
+                   isEncroachingOnEdge(vertices[v2], edgeStart, edgeEnd) ||
+                   (validV && isEncroachingOnEdge(v, edgeStart, edgeEnd)))
                 {
                     encroachedEdges.push(edge);
                 }