How to use Attributes

Generalities about entity attributes

You can retrieve attributes for a wide variety of Datakit classes, any class inheriting from Dtk_Entity or Dtk_DocElement being eligible.
Common entities on which attributes can be found are :

• Dtk_Component
• Dtk_Node
• Dtk_Body
• Topological entities such as Dtk_Face, Dtk_Edge, Dtk_Vertex
• Geometrical entities such as Dtk_Surface, Dtk_Curve, etc.
  Those attributes are stored in Dtk_Info of the entity. See Dtk_DocElement::GetInfos() and Dtk_Entity::get_info().
  The sample below allows you to retrieve common graphical attributes from a Dtk_Node.

Sample code

Dtk_NodePtr layerInfoSetNode;
Dtk_LayerInfosSetPtr layerSet = layerInfoSetNode->GetDtk_LayerInfosSetPtr();
Dtk_NodePtr inNode;
 
/* Get Dtk_InfoPtr class */
Dtk_InfoPtr infos = inNode->GetInfos(); 
 
/* Retrieve inNode blanked status  : -1 = undefined, 0 = Visible, 1=Invisible, 2=Construction Geometry */
int NodeBlankedStatus = infos->GetBlankedStatus();
 
/* Retrieve inNode activation status  :  1 = Activated (Shown), 0 = Disable (Not Shown)*/
int ActivationStatus = infos->GetActivationFlag();
 
/* Retrieve inNode name */
Dtk_string name = infos->GetName();
 
/* Retrieve inNode color RGB */
Dtk_RGB color = infos->GetColor();
 
/* Retrieve inNode layer */
int layer = infos->GetLayer();     
 
/* Retrieve inNode layer name */
Dtk_string layerName;    
layerSet->GetLayerNameById( layer, layerName );
 
/* Retrieve inNode list of layer it appears in */
Dtk_tab<Dtk_Int32> layer = infos->GetlayerList();
 
 
/* Retrieve inNode render information (Lights, texture data) */
Dtk_RenderInfosPtr render = infos->GetRenderInfos();
Dtk_DumpXml_Dtk_RenderInfos(render);

Focus on layers

Calling Dtk_Info::GetLayer() provides a layer identifier, of which the entity belong.
For format allowing an entity to be listed in multiples layers, Dtk_Info::GetlayerList() allow to retrieve the list of layers the entity belong to.
If the said entity appears in only one layer, this call is equivalent to Dtk_Info::GetLayer().

In case the format allows more information relative to layers, such as name assignment or layer filtering, Dtk_LayerInfosSet allows to retrieve those information.
They live in the context of a Dtk_Component.
See Dtk_LayerFilterInfos and Dtk_LayerInfosSet interface and detailed description for more information.

Dtk_LayerInfosSet sample code

/* Set creation */
Dtk_LayerInfosSetPtr in = Dtk_LayerInfosSet::Create( 3 );//Creates a layer set with 3 layers in it.
in->SetLayerID( 0, 42 );
in->SetLayerName( 0, "42" );
in->SetLayerID( 1, 50 );
in->SetLayerName( 1, "Layer fifty" );
in->SetLayerID( 2, 1025 );
in->SetDefaultLayer( 2 );
 
auto const& createdFilter = in->CreateLayerFilterInfos( L"simple filter", L"A simple filter", DTK_FALSE, DTK_TRUE );//Creates a filter that is the default, where none of the set's layers are selected.
createdFilter->SelectLayer( 1 );
createdFilter->SelectLayer( 2 );
 
/* Browse through layers */
for( Dtk_Size_t i = 0; i < in->GetNumLayers(); ++i )
{
     Dtk_string layerName; Dtk_ID layerID;
     in->GetLayerName( i, layerName );
     in->GetLayerID( i, layerID );
}
 
/* Find a specific layer */
Dtk_string layerNameWithID50;
auto status = in->GetLayerNameById( 50, layerNameWithID50 );//Get name of layer with ID 50
if( status != dtkNoError )
     std::cout << "Layer 50 not found" << std::endl;
else
     std::cout << layerNameWithID50 << std::endl;//prints "Layer fifty"
 
/* Find default layer */
Dtk_Size_t defaultIndex = 0;
Dtk_ID defaultLayerID;
status = in->GetDefaultLayer( defaultIndex );
if( status == dtkNoError )
{
     in->GetLayerID( defaultIndex, defaultLayerID );
     std::cout << defaultLayerID << std::endl;//prints 1025
}
 
/* Browse through layer filters */
for( Dtk_Size_t i = 0; i < in->GetNumLayerFilters(); ++i )
{
     auto const& filter = in->GetLayerFilterByPos( i );
 
     Dtk_tab<Dtk_Size_t> outIndexes;
     filter->GetSelectedLayers( outIndexes );
     for( Dtk_Size_t j = 0; j < outIndexes.size(); ++j )
     {
          Dtk_string selectedLayerName; Dtk_ID selectedLayerID;
          in->GetLayerName( outIndexes[ j ], selectedLayerName );
          in->GetLayerID( outIndexes[ j ], selectedLayerID );
     }
}
 
/* Find default layer filter */
Dtk_Size_t defaultFilterIndex = 0;
Dtk_string defaultFilterLayerName, defaultFilterLayerDescription;
status = in->GetDefaultLayerFilter( defaultFilterIndex );
if( status == dtkNoError )
{
     auto const& defaultFilter = in->GetLayerFilterByPos( defaultFilterIndex );
     defaultFilter->GetName( defaultFilterLayerName );
     defaultFilter->GetDescription( defaultFilterLayerDescription );
     std::cout << defaultFilterLayerName << " : " << defaultFilterLayerDescription << std::endl;//prints "simple filter : A simple filter"
}