About

GeData is a container class. This container is used to store data of all Cinema API data types that are supported by Cinema 4D.

Access

A GeData object can be used to directly change the value of a parameter of a C4DAtom object:

C4DAtom::GetParameter(): Gets the value of the given parameter.
C4DAtom::SetParameter(): Sets the value of the given parameter.

Data

Type

A GeData object stores data of a certain type.

GeData::SetDefault(): Sets the default value for the given data type.
::DEFAULTVALUE: Dummy value for the constructor to initialize the object with the default value.

  // Code like this is typically used in a NodeData::Init() function to make sure complex data types are initialized
 
  BaseContainer& bc = ((BaseList2D*)node)->GetDataInstanceRef();
  bc.SetData(1234, GeData { DTYPE_BASELISTLINK, DEFAULTVALUE });

GeData::GetType(): Returns the type of the stored data.

Note: If the type is not set, GeData::GetType() returns ::DA_NIL.

  // Using GetType() it is possible to check if the returned value is of the expected type.
 
  GeData     data;
  const Bool success = sphere->GetParameter(ConstDescID(DescLevel(PRIM_SPHERE_RAD)), data, DESCFLAGS_GET::NONE);
  if (!success)
    return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
 
  // check type
  if (data.GetType() != DA_REAL)
    return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
 
  const Float radius = data.GetFloat();

Access

The GeData class offers access functions for all supported data types. "Set" functions set the value and also change the data type if needed. "Get" functions return the value and are only allowed to be used if the data type matches.

::Int32 and ::Bool data (data type ::DA_LONG):

GeData::GetBool(): Returns the ::Bool value.
GeData::GetInt32(): Returns the ::Int32 value.
GeData::SetInt32(): Sets a ::Int32 value.

::Int64 data (data type ::DA_LLONG):

GeData::GetInt64(): Returns the ::Int64 value.
GeData::SetInt64(): Sets the ::Int64 value.

::Float data (data type ::DA_REAL):

GeData::GetFloat(): Returns the ::Float value.
GeData::SetFloat(): Sets the ::Float value.

Void pointers (data type ::DA_VOID):

GeData::GetVoid(): Returns the void pointer.
GeData::SetVoid(): Stores the void pointer.

    // This example stores a void pointer in a GeData object.
 
    GeData data;
    data.SetVoid(&object);
 
    // ...
 
    SomeObject* const obj = static_cast<SomeObject*>(data.GetVoid());

Note: In general it is not recommended to use "raw" pointers, instead see BaseLink Manual.

Raw memory (data type ::DA_BYTEARRAY):

GeData::GetMemoryAndRelease(): Returns a pointer to the stored memory and hands over the ownership.
GeData::GetMemory(): Returns a pointer to the stored memory.
GeData::SetMemory(): Stores the raw memory.

    // This example stores some raw memory in a GeData object.
 
    GeData geData;
    geData.SetMemory(memory, memSize);
 
    Int count;
    const Char* const data = (Char*)geData.GetMemory(count);
 
    if (data != nullptr)
    {
      String output;
      output.SetCString(data, count);
      ApplicationOutput(output);
    }

::Vector objects (data type ::DA_VECTOR):

GeData::GetVector(): Returns the ::Vector object.
GeData::SetVector(): Stores the ::Vector object.

Copy

The data of one GeData object can easily be copied to another object:

GeData::CopyData(): Copies the data to the given target GeData object.
GeData::operator=: Copies the GeData object.

    // This example copies the data from one GeData
    // object to another.
 
    GeData stringData { "foobar" };
 
    GeData intData(100);
 
    stringData.CopyData(&intData, nullptr);
 
    // check if container contains a String
    if (intData.GetType() == DA_STRING)
      ApplicationOutput("Data: " + intData.GetString());

Clear

A GeData object can be cleared.

GeData::Free(): Deletes all internal data and sets the type to ::DA_NIL.

    // This example stores a String in the given GeData object just do delete it.
 
    GeData data { "foobar" };
 
    // check if container contains a String
    if (data.GetType() == DA_STRING)
      ApplicationOutput("data contains a string"_s);
 
    data.Free();
 
    // check if data has no type (data is not set)
    if (data.GetType() == DA_NIL)
      ApplicationOutput("data is empty"_s);

Compare

Two GeData objects can be compared with the usual operators:

GeData::operator==: Returns true if two GeData objects are equal.
GeData::operator!=: Returns true if two GeData objects are not equal.

    // This example compares two GeData objects with the "same" value but different types.
 
    GeData intergerDataA;
    intergerDataA.SetInt32(123);
 
    GeData integerDataB;
    integerDataB.SetInt64(123);
 
    if (intergerDataA != integerDataB)
      ApplicationOutput("Data is different"_s);

Disc I/O

A GeData object can be stored in a HyperFile:

HyperFile::ReadGeData(): Reads the GeData object from the HyperFile.
HyperFile::WriteGeData(): Writes the GeData object to the HyperFile.

    // This example writes a GeData value to a HyperFile.
 
    AutoAlloc<HyperFile> hf;
    if (hf == nullptr)
      return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION);
 
    // open HyperFile to write
    if (hf->Open(456, filename, FILEOPEN::WRITE, FILEDIALOG::ANY))
    {
      hf->WriteGeData(data);
      hf->Close();
    }
    else
    {
      return maxon::IoError(MAXON_SOURCE_LOCATION, MaxonConvert(filename, MAXONCONVERTMODE::NONE), "Could not open file."_s);
    }

    // This example reads a GeData value from a HyperFile stored on disc.
 
    AutoAlloc<HyperFile> hf;
    if (hf == nullptr)
      return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION);
 
    // open HyperFile to read
    if (hf->Open(456, filename, FILEOPEN::READ, FILEDIALOG::ANY))
    {
      GeData data;
      hf->ReadGeData(&data);
 
      // check if container contains a String
      if (data.GetType() == DA_STRING)
        ApplicationOutput("Loaded GeData String: " + data.GetString());
 
      hf->Close();
    }
    else
    {
      return maxon::IoError(MAXON_SOURCE_LOCATION, MaxonConvert(filename, MAXONCONVERTMODE::NONE), "Could not open file."_s);
    }

Table of Contents

About

Access

Data

Type

Access

Copy

Clear

Compare

Disc I/O

Further Reading