Diffing_Engine: Hash and Diff to leverage new GeometryHash

BHoM_Engine/Query/Hash.cs

@@ -234,6 +234,11 @@ private static string HashString(object obj, BaseComparisonConfig cc, int nestin
                 if (BH.Engine.Base.Compute.TryRunExtensionMethod(obj, "HashString", parameters, out hashStringFromExtensionMethod))
                     return (string)hashStringFromExtensionMethod;
 
+                if (cc.UseGeometryHash && typeof(IGeometry).IsAssignableFrom(type))
+                {
+                    return GeometryHash((IGeometry)obj, cc, currentPropertyFullName);
+                }
+
                 // If the object is an IObject (= a BHoM class), let's look at its properties. 
                 // We only do this for IObjects (BHoM types) since we cannot guarantee full compatibility of the following procedure with any possible (non-BHoM) type.
                 PropertyInfo[] properties = type.GetProperties();
@@ -285,24 +290,23 @@ private static string HashString(object obj, BaseComparisonConfig cc, int nestin
 
         /***************************************************/
 
-        private static double GeometryHash(this IGeometry igeom)
+        private static string GeometryHash(this IGeometry igeom, BaseComparisonConfig comparisonConfig, string fullName)
         {
             if (igeom == null)
-                return default(double);
+                return null;
 
             if (m_GeomHashFunc == null)
             {
                 var mis = Query.ExtensionMethods(typeof(IGeometry), "GeometryHash");
-                m_GeomHashFunc = (Func<IGeometry, double>)Delegate.CreateDelegate(typeof(Func<IGeometry, double>), mis.First());
+                if (!mis?.Any() ?? true)
+                    throw new InvalidOperationException("Could not dynamically load the GeometryHash method.");
+
+                m_GeomHashFunc = (Func<IGeometry, BaseComparisonConfig, string, string>)Delegate.CreateDelegate(typeof(Func<IGeometry, BaseComparisonConfig, string, string>), mis.First());
             }
 
-            return m_GeomHashFunc(igeom);
+            return m_GeomHashFunc(igeom, comparisonConfig, fullName);
         }
 
-        private static Func<IGeometry, double> m_GeomHashFunc = null;
+        private static Func<IGeometry, BaseComparisonConfig, string, string> m_GeomHashFunc = null;
     }
-}
-
-
-
-
+}

Geometry_Engine/Query/GeometryHash.cs

@@ -51,12 +51,12 @@ public static partial class Query
             "\nAdditionally, the resulting points are transformed based on the source geometry type, to remove or minimize collisions." +
             "\n(Any transformation so performed is translational only, in order to support geometrical tolerance, i.e. numerical distance, when comparing GeometryHashes downstream).")]
         [Input("bhomObj", "Input BHoMObject whose geometry will be queried by IGeometry() and which will be used for computing a Geometry Hash.")]
-        [Output("geomHash", "Number representing a unique signature of the input object's geometry.")]
-        public static string GeometryHash(this IBHoMObject bhomObj)
+        [Output("geomHash", "Value representing a unique signature of the input object's geometry.")]
+        public static string GeometryHash(this IBHoMObject bhomObj, BaseComparisonConfig comparisonConfig = null)
         {
             IGeometry igeom = bhomObj.IGeometry();
 
-            return GeometryHash(igeom);
+            return GeometryHash(igeom, comparisonConfig);
         }
 
         /***************************************************/
@@ -66,13 +66,32 @@ public static string GeometryHash(this IBHoMObject bhomObj)
             "\nThe number of points is reduced to the minimum essential to determine uniquely any geometry." +
             "\nAdditionally, the resulting points are transformed based on the source geometry type, to remove or minimize collisions." +
             "\n(Any transformation so performed is translational only, in order to support geometrical tolerance, i.e. numerical distance, when comparing GeometryHashes downstream).")]
-        [Output("geomHash", "Number representing a unique signature of the input geometry.")]
-        public static string GeometryHash(this IGeometry igeometry)
+        [Output("geomHash", "Value representing a unique signature of the input geometry.")]
+        public static string GeometryHash(this IGeometry igeometry, BaseComparisonConfig comparisonConfig = null)
+        {
+            return GeometryHash(igeometry, comparisonConfig, null);
+        }
+
+        /***************************************************/
+
+        [Description("Returns a signature of the input geometry, useful for diffing." +
+            "\nThe hash is computed as a serialised array representing the coordinate of significant points taken on the geometry." +
+            "\nThe number of points is reduced to the minimum essential to determine uniquely any geometry." +
+            "\nAdditionally, the resulting points are transformed based on the source geometry type, to remove or minimize collisions." +
+            "\n(Any transformation so performed is translational only, in order to support geometrical tolerance, i.e. numerical distance, when comparing GeometryHashes downstream).")]
+        [Input("igeometry", "Geometry you want to compute the hash for.")]
+        [Input("comparisonConfig", "Configurations on how the hash is computed, with options for numerical approximation, type exceptions and many others.")]
+        [Input("fullName", "Name of the property that holds the target object to calculate the hash for. This name will be used to seek any matching custom configuration to apply against the `comparisonConfig` input.")]
+        [Output("geomHash", "Value representing a unique signature of the input geometry.")]
+        public static string GeometryHash(this IGeometry igeometry, BaseComparisonConfig comparisonConfig, string fullName)
         {
             if (igeometry == null)
                 return null;
 
-            double[] hashArray = IHashArray(igeometry);
+            double[] hashArray = IHashArray(igeometry, comparisonConfig, fullName);
+            if (hashArray == null)
+                return null;
+
             byte[] byteArray = GetBytes(hashArray);
 
             if (m_SHA256Algorithm == null)
@@ -93,6 +112,9 @@ public static string GeometryHash(this IGeometry igeometry)
 
         private static byte[] GetBytes(this double[] values)
         {
+            if (values == null)
+                return default;
+
             return values.SelectMany(value => BitConverter.GetBytes(value)).ToArray();
         }