Actually use the same node positions internally and externally.

src/FlatLayerVisualisation.hpp

@@ -26,6 +26,24 @@ namespace fmri
         std::unique_ptr<float[]> colorBuffer;
         std::unique_ptr<int[]> indexBuffer;
 
+        static constexpr const std::array<float, 12> NODE_SHAPE = {
+                -0.5f, 0, 0.5f,
+                0, 0, -0.5f,
+                0, 1, 0,
+                0.5f, 0, 0.5f
+        };
+        static constexpr const std::array<int, 12> NODE_FACES = {
+                0, 1, 2,
+                0, 1, 3,
+                0, 2, 3,
+                1, 2, 3
+        };
+
         void setVertexPositions(int vertexNo, float *destination);
+
+        // Various functions defining the way the nodes will be aligned.
+        void initializeNodePositions();
+        void computeNodePositionsLine();
+        void computeNodePositionsSquare();
     };
 }