[C4D] Calling MCOMMAND_CURRENTSTATETOOBJECT on an object... the proper way

c4d-csto.cpp

/// Calls MCOMMAND_CURRENTSTATETOOBJECT on an object and returns the result
///
/// @note: This is time and memory consuming, so only do it when necessary, and then cache the result!
///
/// @param[in] op The object you want to CSTO
/// @return The resulting object. Caller owns the pointed object.
PolygonObject* CurrentStateToObject(BaseObject *op)
{
	// Create AliasTranslate
	AutoAlloc<AliasTrans> aliasTrans;
	if (!aliasTrans || !aliasTrans->Init(op->GetDocument()))
		return nullptr;
	
	// Create clone of op. We only need this clone for the modeling command.
	BaseObject *tmpOp = static_cast<BaseObject*>(op->GetClone(COPYFLAGS_0, aliasTrans));
	if (!tmpOp)
		return nullptr;
	
	// Translate BaseLinks, maybe the cloned object needs that
	aliasTrans->Translate(true);
	
	// Create temporary document
	AutoAlloc<BaseDocument> tmpDoc;
	if (!tmpDoc)
	{
		// Free tmpOp and return
		BaseObject::Free(tmpOp);
		return nullptr;
	}
	
	// Insert tmpOp into tmpDoc. From now on, tmpDoc has the ownership over tmpOp,
	// so we don't need to free tmpOp manually anymore (because tmpDoc will auto-free itself at the end of the scope, as we used AutoAlloc to create it).
	tmpDoc->InsertObject(tmpOp, nullptr, nullptr);
	
	// Build modeling command data
	ModelingCommandData mcd;
	mcd.doc = tmpDoc;
	mcd.op = tmpOp;
	
	// Perform modeling command
	if (!SendModelingCommand(MCOMMAND_CURRENTSTATETOOBJECT, mcd))
		return nullptr;
	
	// Get result
	PolygonObject *res = static_cast<PolygonObject*>(mcd.result->GetIndex(0));
	
	// Set original matrix
	if (res)
		res->SetMg(op->GetMg());
	
	// Return result
	return res;
}