engine/items/source/ItemMaterialFilter.cpp
// The item passes the filter when the item:
// - Is non-null
// - Matches the material
The item passes the filter when the item:
Is non-null
Matches the material
The item passes the filter when the item : Is non - null Matches the material
bool ItemMaterialFilter::passes_filter(ItemPtr item) const
{
  bool passes = false;
  if (item)
  {
    passes = (material == item->get_material_type());
  }
  return passes;
}
bool ItemMaterialFilter :: passes_filter ( ItemPtr item ) const { bool passes = false ; if ( item ) { passes = ( material == item -> get_material_type ( ) ) ; } return passes ; }
The item passes the filter when the item:
 Is non-null
 Matches the material
The item passes the filter when the item : Is non - null Matches the material