AAX CompareState

[stw]

I need some assistance to get this work properly.
I'm using chunks to store some arbitrary data beside the normal params. This worked fine so far in AU/VST and AAX builds. But it turns out that as soon as i add any parameter to my SerializeState() the ProTools compare is messed up.
For testing purpose I stripped it down to just implementing this in my .cpp

bool MyPlug::SerializeState(ByteChunk* pChunk)
{
  IMutexLock lock(this);
  //pChunk->Put(&test);      /* test declared as double in .h */
  return IPlugBase::SerializeParams(pChunk);
}


int MyPlug::UnserializeState(ByteChunk* pChunk, int startPos)
{
  IMutexLock lock(this);
  //startPos = pChunk->Get(&test, startPos);
  return IPlugBase::UnserializeParams(pChunk, startPos);
}


bool MyPlug::CompareState(const unsigned char* incomingState, int startPos)
{
  bool isEqual = true;
  //startPos = sizeof(double);  
  isEqual &= IPlugBase::CompareState(incomingState, startPos);  
  return isEqual;
}

As long as the lines are commented out everything works fine. Just serializing that one double makes the Compare button always lit. Seems like the startPos for IPlugBase::CompareState points to a wrong position?
However i can't get it work. What am i doing wrong?

[Tale]

I have no hands on experience with this, but I think something like this might work:

bool MyPlug::CompareState(const unsigned char* incomingState, int startPos)
{
  bool isEqual = true;

  const double* pTest = (const double*)incomingState;
  isEqual &= *pTest == test; // Or: mTest, because it is a member variable
  startPos += sizeof(double);

  isEqual &= IPlugBase::CompareState(incomingState, startPos);  
  return isEqual;
}

BTW, I see IPlugBase::CompareState compares doubles as floats... I guess this is not necessary if you #define PLUG_DOES_STATE_CHUNKS 1, so a simple memcmp() might also do the trick.

[stw]

Hi Tale,
thanks for answering. I'll try your suggestions.
However the point in this case is not that something goes wrong with the comparison (of the test var) itself. In fact my approach should leave the serialized test variable out of the process since (at least this was my understanding) IPlugBase::CompareState(incomingState, startPos) should only test against all other regular params when startPos is set to sizeof(double). But maybe i'm totally wrong with that idea...

BTW: I did #define PLUG_DOES_STATE_CHUNKS 1

[Tale]

Originally Posted by stw

In fact my approach should leave the serialized test variable out of the process since (at least this was my understanding)

Ah I see. Well, then you should probably only do startPos += sizeof(double) before calling IPlugBase::CompareState().

[stw]

Originally Posted by Tale

Ah I see. Well, then you should probably only do startPos += sizeof(double) before calling IPlugBase::CompareState().

Yes, that's what i did .
I'm not sure if i should "+=", or "=" startPos though both should do the same in that case. If i follow the IPlugChunks example "=" would be correct.

[Tale]

Originally Posted by stw

I'm not sure if i should "+=", or "=" startPos though both should do the same in that case. If i follow the IPlugChunks example "=" would be correct.

Yeah, but I disagree with the example, because the related UnserializeState() doesn't necessarily start at 0. However, for CompareState() indeed it doesn't matter, because in the current implementation it does always start at 0.