Assorted cleanup and comments.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@2693 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Plugins/Plugin_VideoDX9/Src/NativeVertexFormat.cpp

@@ -99,7 +99,7 @@ void D3DVertexFormat::Initialize(const PortableVertexDeclaration &_vtx_decl)
 	
 	// So, here we go. First position:
 	int elem_idx = 0;
-	elems[elem_idx].Offset = 0;  // Positions are always first, at position 0.
+	elems[elem_idx].Offset = 0;  // Positions are always first, at position 0. Always float3.
 	elems[elem_idx].Type = D3DDECLTYPE_FLOAT3;
 	elems[elem_idx].Usage = D3DDECLUSAGE_POSITION;
 	++elem_idx;