Added C# code tabs to SurfaceTool.rst (godotengine#8192)

* Added C# code tabs

* Update tutorials/3d/procedural_geometry/surfacetool.rst

---------

Co-authored-by: A Thousand Ships <[email protected]>

Author: HDLcincDragon

tutorials/3d/procedural_geometry/surfacetool.rst

@@ -21,6 +21,14 @@ Attributes are added before each vertex is added:
     st.add_vertex() # Captures normal and color above.
     st.set_normal() # Normal never added to a vertex.
 
+ .. code-tab:: csharp
+    
+    st.SetNormal(); // Overwritten by normal below.
+    st.SetNormal(); // Added to next vertex.
+    st.SetColor(); // Added to next vertex.
+    st.AddVertex(); // Captures normal and color above.
+    st.SetNormal(); // Normal never added to a vertex.
+
 When finished generating your geometry with the :ref:`SurfaceTool <class_surfacetool>`
 call ``commit()`` to finish generating the mesh. If an :ref:`ArrayMesh <class_ArrayMesh>` is passed
 to ``commit()`` then it appends a new surface to the end of the ArrayMesh. While if nothing is passed
@@ -33,6 +41,12 @@ in, ``commit()`` returns an ArrayMesh.
     # Or:
     var mesh = st.commit()
 
+ .. code-tab:: csharp
+
+    st.Commit(mesh);
+    // Or:
+    var mesh = st.Commit();
+
 Code creates a triangle with indices
 
 .. tabs::
@@ -59,6 +73,29 @@ Code creates a triangle with indices
     # Commit to a mesh.
     var mesh = st.commit()
 
+ .. code-tab:: csharp
+
+    var st = new SurfaceTool();
+
+    st.Begin(Mesh.PrimitiveType.Triangles);
+
+    // Prepare attributes for AddVertex.
+    st.SetNormal(new Vector3(0, 0, 1));
+    st.SetUV(new Vector2(0, 0));
+    // Call last for each vertex, adds the above attributes.
+    st.AddVertex(new Vector3(-1, -1, 0));
+
+    st.SetNormal(new Vector3(0, 0, 1));
+    st.SetUV(new Vector2(0, 1));
+    st.AddVertex(new Vector3(-1, 1, 0));
+
+    st.SetNormal(new Vector3(0, 0, 1));
+    st.SetUV(new Vector2(1, 1));
+    st.AddVertex(new Vector3(1, 1, 0));
+
+    // Commit to a mesh.
+    var mesh = st.Commit();
+
 You can optionally add an index array, either by calling ``add_index()`` and adding
 vertices to the index array or by calling ``index()`` which shrinks the vertex array
 to remove duplicate vertices.
@@ -67,7 +104,7 @@ to remove duplicate vertices.
  .. code-tab:: gdscript GDScript
 
     # Creates a quad from four corner vertices.
-    # Add_index does not need to be called before add_vertex.
+    # add_index does not need to be called before add_vertex.
     st.add_index(0)
     st.add_index(1)
     st.add_index(2)
@@ -79,6 +116,21 @@ to remove duplicate vertices.
     # Alternatively:
     st.index()
 
+ .. code-tab:: csharp
+
+    // Creates a quad from four corner vertices.
+    // AddIndex does not need to be called before AddVertex.
+    st.AddIndex(0);
+    st.AddIndex(1);
+    st.AddIndex(2);
+
+    st.AddIndex(1);
+    st.AddIndex(3);
+    st.AddIndex(2);
+
+    // Alternatively:
+    st.Index();
+
 Similarly, if you have an index array, but you want each vertex to be unique (e.g. because
 you want to use unique normals or colors per face instead of per-vertex), you can call ``deindex()``.
 
@@ -87,6 +139,10 @@ you want to use unique normals or colors per face instead of per-vertex), you ca
 
     st.deindex()
 
+ .. code-tab:: csharp
+
+    st.Deindex();
+
 If you don't add custom normals yourself, you can add them using ``generate_normals()``, which should
 be called after generating geometry and before committing the mesh using ``commit()`` or
 ``commit_to_arrays()``. Calling ``generate_normals(true)`` will flip the resulting normals. As a side
@@ -105,6 +161,11 @@ normals set already.
     st.generate_normals()
     st.generate_tangents()
 
+ .. code-tab:: csharp
+    
+    st.GenerateNormals();
+    st.GenerateTangents();
+
 By default, when generating normals, they will be calculated on a per-face basis. If you want
 smooth vertex normals, when adding vertices, call ``add_smooth_group()``. ``add_smooth_group()``
 needs to be called while building the geometry, e.g. before the call to ``add_vertex()``