From e4a16a735968a8a4fc7934ab5d740d81116c0bd6 Mon Sep 17 00:00:00 2001
From: artem-ogre <artem.ogre@gmail.com>
Date: Mon, 21 Aug 2023 15:15:03 +0200
Subject: [PATCH] #7 Refactor edgeTriangle

---
 CDT/include/Triangulation.h   |  2 +-
 CDT/include/Triangulation.hpp | 60 +++++++++++++++--------------------
 2 files changed, 26 insertions(+), 36 deletions(-)

diff --git a/CDT/include/Triangulation.h b/CDT/include/Triangulation.h
index 267afff..0e52e25 100644
--- a/CDT/include/Triangulation.h
+++ b/CDT/include/Triangulation.h
@@ -516,7 +516,6 @@ class CDT_EXPORT Triangulation
         VertInd iV2,
         VertInd iV3,
         VertInd iV4) const;
-    TriInd edgeTriangle(Edge edge) const;
     bool isRefinementNeeded(
         const Triangle& tri,
         RefinementCriterion::Enum refinementCriterion,
@@ -615,6 +614,7 @@ class CDT_EXPORT Triangulation
         VertInd superGeomVertCount,
         V2d<T> boxMin,
         V2d<T> boxMax);
+    std::pair<TriInd, TriInd> edgeTriangles(VertInd a, VertInd b) const;
     bool hasEdge(VertInd a, VertInd b) const;
     void setAdjacentTriangle(const VertInd v, const TriInd t);
     void pivotVertexTriangleCW(VertInd v);
diff --git a/CDT/include/Triangulation.hpp b/CDT/include/Triangulation.hpp
index 4855dcb..59a666e 100644
--- a/CDT/include/Triangulation.hpp
+++ b/CDT/include/Triangulation.hpp
@@ -1262,26 +1262,6 @@ bool Triangulation<T, TNearPointLocator>::isFlipNeeded(
     return isInCircumcircle(v, v2, v3, v4);
 }
 
-template <typename T, typename TNearPointLocator>
-TriInd Triangulation<T, TNearPointLocator>::edgeTriangle(const Edge edge) const
-{
-    TriInd iT = invalidIndex;
-    const TriInd start = m_vertTris[edge.v1()];
-    TriInd currTri = start;
-    do
-    {
-        const Triangle& t = triangles[currTri];
-        if(t.next(edge.v1()).second == edge.v2())
-        {
-            iT = currTri;
-            break;
-        }
-        currTri = t.next(edge.v1()).first;
-    } while(currTri != start);
-    assert(iT != invalidIndex);
-    return iT;
-}
-
 template <typename T, typename TNearPointLocator>
 bool Triangulation<T, TNearPointLocator>::isRefinementNeeded(
     const Triangle& tri,
@@ -1314,8 +1294,9 @@ EdgeQue Triangulation<T, TNearPointLocator>::detectEncroachedEdges()
         ++cit)
     {
         const Edge edge = *cit;
-        const TriInd iT = edgeTriangle(edge);
-        const TriInd iTopo = edgeNeighbor(triangles[iT], edge.v1(), edge.v2());
+        TriInd iT, iTopo;
+        std::tie(iT, iTopo) = edgeTriangles(edge.v1(), edge.v2());
+        assert(iT != invalidIndex && iTopo != invalidIndex);
         const Triangle& t = triangles[iT];
         const Triangle& tOpo = triangles[iTopo];
         VertInd v1 = opposedVertex(t, iTopo);
@@ -1372,13 +1353,11 @@ TriIndVec Triangulation<T, TNearPointLocator>::resolveEncroachedEdges(
         {
             continue;
         }
-        TriInd iT = edgeTriangle(edge);
-        const Triangle& t = triangles[iT];
-        VertInd i = splitEncroachedEdge(
-            edge,
-            iT,
-            edgeNeighbor(triangles[iT], edge.v1(), edge.v2()),
-            steinerVerticesOffset);
+        TriInd iT, iTopo;
+        std::tie(iT, iTopo) = edgeTriangles(edge.v1(), edge.v2());
+        assert(iT != invalidIndex && iTopo != invalidIndex);
+        const VertInd i =
+            splitEncroachedEdge(edge, iT, iTopo, steinerVerticesOffset);
         --newVertBudget;
 
         TriInd start = m_vertTris[i];
@@ -2210,23 +2189,34 @@ void Triangulation<T, TNearPointLocator>::insertVertices_KDTreeBFS(
 }
 
 template <typename T, typename TNearPointLocator>
-bool Triangulation<T, TNearPointLocator>::hasEdge(
+std::pair<TriInd, TriInd> Triangulation<T, TNearPointLocator>::edgeTriangles(
     const VertInd a,
     const VertInd b) const
 {
     const TriInd triStart = m_vertTris[a];
     assert(triStart != noNeighbor);
-    TriInd iT = triStart;
+    TriInd iT = triStart, iTNext = triStart;
     VertInd iV = noVertex;
     do
     {
         const Triangle& t = triangles[iT];
-        tie(iT, iV) = t.next(a);
-        assert(iT != noNeighbor);
+        tie(iTNext, iV) = t.next(a);
+        assert(iTNext != noNeighbor);
         if(iV == b)
-            return true;
+        {
+            return std::make_pair(iT, iTNext);
+        }
+        iT = iTNext;
     } while(iT != triStart);
-    return false;
+    return std::make_pair(invalidIndex, invalidIndex);
+}
+
+template <typename T, typename TNearPointLocator>
+bool Triangulation<T, TNearPointLocator>::hasEdge(
+    const VertInd a,
+    const VertInd b) const
+{
+    return edgeTriangles(a, b).first != invalidIndex;
 }
 
 template <typename T, typename TNearPointLocator>