CreateLabelEx

The CreateLabelEx method creates a label in the 3D Window.

While more efficient than the CreateLabel method, CreateLabelEx cannot be used through a scripting language. In contrast to the CreateLabel method, this method allows the client to set all of the label properties at creation time (via its LabelInfo parameter). Passing the LabelInfo as a well-defined struct is more efficient than the scripting object which is used in CreateLabel. When creating large numbers of labels at once, this method avoids unnecessary round trips between the client and TerraExplorer and therefore performs much more efficiently.

HRESULT CreateLabelEx

[in] LabelStruct LabelInfo,

[in] double X,

[in] double Y,

[in] double Elevation,

[in, defaultvalue(0)] HeightStyleCode HeightStyle,

[in, defaultvalue(0)] long GroupID,

[in, defaultvalue("")] BSTR Description,

[out, retval] ITerrainLabel5** pITerrainLabel5)

Parameters:

• LabelInfo – A structure containing all of the label properties’ settings.
  See:  ITerrainLable::GetLabelStruct() method for details about this structure.

• X – The West-East coordinate of the center of the label represented in MPT units. You can use the ITerrain interface to retrieve information about the MPT units. If you are working in Lat-Long format, the Lat-Long values are in decimal Lat-Long.

• Y – The North-South coordinate of the center of the label represented in MPT units. You can use the ITerrain interface to retrieve information about the MPT units. If you are working in Lat-Long format, the Lat-Long values are in decimal Lat-Long.

• Elevation – The elevation of the label relative to the terrain.

• HeightStyle – An enum determining how the label is placed on the terrain.

The HeightStyleCode enum can use any of the following values:

• HSC_TERRAIN_RELATIVE = 0
  The height above the terrain of the label’s pivot (the center of its base), is determined by the Elevation points in the SafeArrayVertices parameter. Each of the base vertices lies in the same plane as the object’s pivot.

• HSC_TERRAIN_ABSOLUTE = 3
  The height relative to the terrain database vertical datum base ellipsoid of the label’s pivot (the center of its base) , is determined by the Elevation points in the SafeArrayVertices parameter. Each of the base vertices lies in the same plane as the object’s pivot.

• GroupID – The Information Tree group in which the label is created. If it is set to zero, the object is created under the root. You can obtain the GroupID by one of the following methods:

• Create the group the IInformationTree5::CreateGroup.

• If you know the name of the group, find it using IInformationTree5::FindItem.

• Traverse the Tree using IInformationTree5 methods such as GetNextItem, until you come to the desired GroupID.

• Description – The name of the label as it appears in the Information Window. If an empty string is passed into this parameter, TerraExplorer assigns it a unique name.

• pITerrainLabel5 – An interface pointer to the newly created label. This parameter must not be Null.

Return Values:

The return value obtained from the returned HRESULT can be one of the following: