calling CustomDataTypeClass::Calculate() [SOLVED]

  • On 27/07/2016 at 03:40, xxxxxxxx wrote:

    User Information:
    Cinema 4D Version:   R17 
    Language(s) :     C++  ;

    Hi! I'm trying to interpolate between two GeData values. But when I call CustomDataTypeClass::Calculate(),
    it always gives me GV_CALC_ERR_UNDEFINED . Does someone know what I'm doing wrong?

    Thanks a lot in advance,


    GeData InterpolateValues(GeData const& left, GeData const& right, BaseList2D* node, Float w) {
      Int32 const type = left.GetType();
      if (type != right.GetType()) return left;
      // Load the CustomDataTypeClass plugin for this datatype.
      CUSTOMDATATYPEPLUGIN* plug = FindCustomDataTypePlugin(left.GetType());
      if (!plug) return left;
      auto data = static_cast<CustomDataTypeClass*>(plug->adr);
      if (!data) return left;
      GeData res = left;
      GvError err = (data->*plug->Calculate)(
      if (err != GV_IO_ERR_NONE) {
        // Always gets here with err == GV_CALC_ERR_UNDEFINED
        GePrint("Oh Noes! " + String::IntToString(err));
      return res;
            // Calling example
    	GeData l(10);
    	GeData r(50);
    	GeData res = InterpolateValues(l, r, nullptr, 0.5);
    	Int32 val = res.GetInt32();

  • On 28/07/2016 at 08:22, xxxxxxxx wrote:

    Hi Niklas,

    I'm terribly sorry, I haven't found as much time to investigate it, as I had planned and wished.
    Just wanted to let you know, I'm on it.
    What I found so far: Your Calculate() call ends up in the "base implementation" of that function, which does nothing more than returning GV_CALC_ERR_UNDEFINED. So actually under the given circumstances, the result is actually correct 😉
    I'll continue with this tomorrow.

  • On 29/07/2016 at 08:58, xxxxxxxx wrote:

    Hi Niklas,

    the reason is quite simple: Only very few custom data types implement Calculate(). From the public ones, SplineData is actually the only one (and even this implements only GV_CALC_CLR, GV_CALC_ADD and GV_CALC_MIX).
    So actually your example is correct, but it works only on data types that implemented Calculate()... SplineData that is. 😊

  • On 29/07/2016 at 10:51, xxxxxxxx wrote:

    Thank you for your time and effort, Andreas. :) Originally I didn't expect FindCustomDataTypePlugin()
    to actually return not-null for any of the standard datatypes (LONG, REAL, etc.), but since it did, I
    expected it to be implemented for these types as well.

    Anyway, now that I know I just do some special handling for the datatypes that I want to support
    proper interpolation for, and eventually use the CustomDataTypePlugin for any ID that I don't know
    or don't handle.

    Thanks again!

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