Only store one set of vertices in edge struct

QTProject/subdivision.cpp

@@ -148,43 +148,44 @@ Subdivision::Tables Subdivision::precomputeTables(Input input) {
          * - Each edge point will be computed twice. This allows us to implicitly know the adjacent points.
          */
 
-        Triangle::Shared_Edge edge;
-        Triangle::Shared_Edge uv, vw, wu;
+        Triangle::Edge edge_a, edge_b;
+        // These will hold the edges of the triangles next to the current one. uv will hold the edge shared with the current triangle's uv edge.
+        Triangle::Edge uv, vw, wu;
         for (int j = 0; j < triangles.length(); j++){
             if (j != i) {
-                if (triangle.get_shared_edge(triangles[j], edge)) {
-                    switch (edge.edge_a) {
-                        case Triangle::Shared_Edge::Edge::uv:
-                            uv = edge;
+                if (triangle.get_shared_edge(triangles[j], edge_a, edge_b)) {
+                    switch (edge_a.name) {
+                        case Triangle::Edge::Name::uv:
+                            uv = edge_b;
                             break;
-                        case Triangle::Shared_Edge::Edge::vw:
-                            vw = edge;
+                        case Triangle::Edge::Name::vw:
+                            vw = edge_b;
                             break;
-                        case Triangle::Shared_Edge::Edge::wu:
-                            wu = edge;
+                        case Triangle::Edge::Name::wu:
+                            wu = edge_b;
                             break;
                         default:
-                            qWarning() << "got" << edge.edge_a << "as edge!";
+                            qWarning() << "got" << edge_a.name << "as edge!";
                             break;
                     }
                 }
             }
         }
 
-        tables.edge_indices.push_back(uv.a1);
-        tables.edge_indices.push_back(uv.a2);
-        tables.edge_indices.push_back(uv.a3);
-        tables.edge_indices.push_back(uv.b3);
+        tables.edge_indices.push_back(triangle.u_idx());
+        tables.edge_indices.push_back(triangle.v_idx());
+        tables.edge_indices.push_back(triangle.w_idx());
+        tables.edge_indices.push_back(uv.c);
 
-        tables.edge_indices.push_back(vw.a1);
-        tables.edge_indices.push_back(vw.a2);
-        tables.edge_indices.push_back(vw.a3);
-        tables.edge_indices.push_back(vw.b3);
+        tables.edge_indices.push_back(triangle.v_idx());
+        tables.edge_indices.push_back(triangle.w_idx());
+        tables.edge_indices.push_back(triangle.u_idx());
+        tables.edge_indices.push_back(vw.c);
 
-        tables.edge_indices.push_back(wu.a1);
-        tables.edge_indices.push_back(wu.a2);
-        tables.edge_indices.push_back(wu.a3);
-        tables.edge_indices.push_back(wu.b3);
+        tables.edge_indices.push_back(triangle.w_idx());
+        tables.edge_indices.push_back(triangle.u_idx());
+        tables.edge_indices.push_back(triangle.v_idx());
+        tables.edge_indices.push_back(wu.c);
 
         //add indices to new index buffer
         tables.index_buffer.push_back(x_i);

QTProject/triangle.cpp

@@ -2,7 +2,7 @@
 
 #include "triangle.h"
 
-Triangle::Shared_Edge::Edge rotate_edge_enum(Triangle::Shared_Edge::Edge edge);
+Triangle::Edge::Name rotate_edge_name(Triangle::Edge::Name edge);
 
 Triangle::Triangle() {}
 
@@ -44,69 +44,63 @@ int Triangle::w_idx() const {
     return w_;
 }
 
-bool Triangle::get_shared_edge(Triangle other, Shared_Edge &edge) const {
-    if (get_shared_edge_(other, edge)) {
+bool Triangle::get_shared_edge(Triangle other, Edge &edge_a, Edge &edge_b) const {
+    if (get_shared_edge_(other, edge_a, edge_b)) {
         return true;
     }
 
     other.rotate_indices();
-    if (get_shared_edge_(other, edge)) {
-        edge.edge_b = rotate_edge_enum(rotate_edge_enum(edge.edge_b));
+    if (get_shared_edge_(other, edge_a, edge_b)) {
+        edge_b.name = rotate_edge_name(rotate_edge_name(edge_b.name));
         return true;
     }
 
     other.rotate_indices();
-    if (get_shared_edge_(other, edge)) {
-        edge.edge_b = rotate_edge_enum(edge.edge_b);
+    if (get_shared_edge_(other, edge_a, edge_b)) {
+        edge_b.name = rotate_edge_name(edge_b.name);
         return true;
     }
 
     return false;
 }
 
-bool Triangle::get_shared_edge_(const Triangle &other, Shared_Edge &edge) const {
+bool Triangle::get_shared_edge_(const Triangle &other, Edge &edge_a, Edge &edge_b) const {
     if (u().samePos(other.u())) {
         if (v().samePos(other.w())) {
-            edge.edge_a = Triangle::Shared_Edge::Edge::uv;
-            edge.edge_b = Triangle::Shared_Edge::Edge::wu;
+            edge_a.name = Triangle::Edge::Name::uv;
+            edge_a.a = u_idx();
+            edge_a.b = v_idx();
+            edge_a.c = w_idx();
 
-            edge.a1 = u_idx();
-            edge.b1 = other.w_idx();
-
-            edge.a2 = v_idx();
-            edge.b2 = other.u_idx();
-
-            edge.a3 = w_idx();
-            edge.b3 = other.v_idx();
+            edge_b.name = Triangle::Edge::Name::wu;
+            edge_b.a = other.w_idx();
+            edge_b.b = other.u_idx();
+            edge_b.c = other.v_idx();
 
             return true;
         } else if (w().samePos(other.v())) {
-            edge.edge_a = Triangle::Shared_Edge::Edge::wu;
-            edge.edge_b = Triangle::Shared_Edge::Edge::uv;
-
-            edge.a1 = u_idx();
-            edge.b1 = other.u_idx();
+            edge_a.name = Triangle::Edge::Name::wu;
+            edge_a.a = w_idx();
+            edge_a.b = u_idx();
+            edge_a.c = v_idx();
 
-            edge.a2 = w_idx();
-            edge.b2 = other.v_idx();
-
-            edge.a3 = v_idx();
-            edge.b3 = other.w_idx();
+            edge_b.name = Triangle::Edge::Name::uv;
+            edge_b.a = other.u_idx();
+            edge_b.b = other.v_idx();
+            edge_b.c = other.w_idx();
 
             return true;
         }
     } else if (v().samePos(other.u()) && w().samePos(other.w())) {
-        edge.edge_a = Triangle::Shared_Edge::Edge::vw;
-        edge.edge_b = Triangle::Shared_Edge::Edge::wu;
-
-        edge.a1 = v_idx();
-        edge.b1 = other.w_idx();
-
-        edge.a2 = w_idx();
-        edge.b2 = other.u_idx();
+        edge_a.name = Triangle::Edge::Name::vw;
+        edge_a.a = v_idx();
+        edge_a.b = w_idx();
+        edge_a.c = u_idx();
 
-        edge.a3 = u_idx();
-        edge.b3 = other.v_idx();
+        edge_b.name = Triangle::Edge::Name::wu;
+        edge_b.a = other.w_idx();
+        edge_b.b = other.u_idx();
+        edge_b.c = other.v_idx();
 
         return true;
     }
@@ -155,17 +149,17 @@ void Triangle::rotate_indices() {
     w_ = a;
 }
 
-Triangle::Shared_Edge::Edge rotate_edge_enum(Triangle::Shared_Edge::Edge edge) {
+Triangle::Edge::Name rotate_edge_name(Triangle::Edge::Name edge) {
     switch (edge) {
-        case Triangle::Shared_Edge::Edge::uv:
-            return Triangle::Shared_Edge::Edge::vw;
-        case Triangle::Shared_Edge::Edge::vw:
-            return Triangle::Shared_Edge::Edge::wu;
-        case Triangle::Shared_Edge::Edge::wu:
-            return Triangle::Shared_Edge::Edge::uv;
+        case Triangle::Edge::Name::uv:
+            return Triangle::Edge::Name::vw;
+        case Triangle::Edge::Name::vw:
+            return Triangle::Edge::Name::wu;
+        case Triangle::Edge::Name::wu:
+            return Triangle::Edge::Name::uv;
         default:
             qDebug() << "Default case should be unreachable";
-            return Triangle::Shared_Edge::Edge::uv;
+            return Triangle::Edge::Name::uv;
     }
 }
 

QTProject/triangle.h

@@ -8,30 +8,17 @@
 
 class Triangle {
     public:
-        /**
-         * Stores the indices of the shared edge of two triangles as well as the other two indices.
-         *
-         * a_* are the indices of the first triangle, b_* those of the second triangle.
-         *
-         * The vertices at a_1 and b_1 are at the same position as are those at a_2 and b_2.
-         *
-         * edge_a describes which edge of the first triangle is part of the shared edge.
-         */
-        struct Shared_Edge {
-            enum Edge {
+        struct Edge {
+            enum Name {
                 uv,
                 vw,
                 wu
             };
 
-            Edge edge_a;
-            Edge edge_b;
-            unsigned int a1;
-            unsigned int b1;
-            unsigned int a2;
-            unsigned int b2;
-            unsigned int a3;
-            unsigned int b3;
+            Name name;
+            unsigned int a;
+            unsigned int b;
+            unsigned int c;
         };
 
         Triangle();
@@ -46,7 +33,7 @@ class Triangle {
         int v_idx() const;
         int w_idx() const;
 
-        bool get_shared_edge(Triangle other, Shared_Edge &edge) const;
+        bool get_shared_edge(Triangle other, Edge &edge_a, Edge &edge_b) const;
 
         Triangle &operator=(const Triangle &other);
 
@@ -62,7 +49,7 @@ class Triangle {
         int w_;
 
         void rotate_indices();
-        bool get_shared_edge_(const Triangle &other, Shared_Edge &edge) const;
+        bool get_shared_edge_(const Triangle &other, Edge &edge_a, Edge &edge_b) const;
 };
 
 QDebug operator<<(QDebug d, const Triangle &triangle);