+/**
+ * RoamDiamond:
+ *
+ * When two adjacent triangles are split, they, along with the four new child
+ * triangles, are added to a diamond which keeps track of them.
+ *
+ * Like triangles, diamond have an error associated with it. However, when a
+ * diamonds error is small enough it is "merged". That is, the diamond along
+ * with the child triangles is removed and the original two triangles triangles
+ * are added back into the mesh.
+ */