Mechanical Modeler

What You Will Learn With This Use Case

This use case illustrates how to create new Combined Curve instances.

To achieve this goal, two steps are necessary:

1. First, defining a Combined Curve Factory Interface and choosing what object will implement it
2. Then, implementing this Interface to instantiate the Combined Curve StartUp into Combined Curve Instances.

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The CAAMmrCombinedCurve Use Case

CAAMmrCombinedCurve is a use case of the CAAMechanicalModeler.edu framework that illustrates MechanicalModeler framework capabilities.

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What Does the CAAMmrCombinedCurve Do

This use case makes it possible to create run time Instances of Combined Curve from the Combined Curve StartUp. Of course, this new skill means a new Interface. It will be called CAAIMmrCombinedCurveFactory. Its definition is straightforward, it could be translated in "create a Combined Curve from its two input curves and its two input directions". 

CAAIMmrCombinedCurveFactory Interface's definition is very simple. A single method is enough to create any Combined Curve, whatever its input Curves and Directions are:

CAAIMmrCombinedCurveFactory::CreateCombinedCurve( Curve1,
                                                  Direction1,
                                                  Curve2,
                                                  Direction2 , 
                                                  Output CombinedCurve )

Now that you have defined this new factory Interface, you have to choose a good candidate to implement it. As described in the technical article entitled "Creating a New StartUp deriving from a Mechanical StartUp" [1], the candidate is CATPrtCont the container of specifications [2].

To create Combined Curve instances, CATPrtCont has to implement CAAIMmrCombCrvFactory interface and CombinedCurve has to implement an interface of type, CAAIMmrCombinedCurve [3], to valuate the attributes.

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How to Launch CAAMmrCombinedCurve

See the section entitled "How to Launch the Combined Curve Use Case" in the "Creating a New Geometrical Feature: The Combined Curve" use case for a detailed description of how this use case should be launched.

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Where to Find the CAAMmrCombinedCurve Code

The CAAMmrCombinedCurve use case is made of a several classes located in the CAAMmrCombinedCurve.m module of the CAAMechanicalModeler.edu framework:

where InstallRootDirectory is the directory where the CAA CD-ROM is installed.

• in the src directory
  • CATIMmrCombCrvFactory.cpp
  • TIE_CATIMmrCombCrvFactory.cpp
  • CATEMmrCombCrvFactory.cpp, the implementation of the CATIMmrCombCrvFactory interface
• in the LocalInterfaces directory
  • CATEMmrCombCrvFactory.h

In the ProtectedInterfaces of the CAAMechanicalModeler.edu framework there is the CATIMmrCombCrvFactory.h file.

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Step-by-Step

This use case is divided into the following steps:

• Defining the Combined Curve Factory Interface
• Implementing the Combined Curve Factory Interface
  • Retrieving the Combined Curve's StartUp
  • Creating a Combined Curve Instance
  • Subscribing to repository for Configuration Data Storage
  • Getting Feature Type Information for BackUp / StartUp management
  • Setting Default Values for the Instance Attributes

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Defining the Combined Curve Factory Interface

The Combined Curve Factory Interface (CAAIMmrCombCrvFactory) is pretty simple: a single method is enough to create a Combined Curve.

Here is its description. This is the main part of CAAIMmrCombCrvFactory.h:

class ExportedByCAAMmrCombinedCurve CAAIMmrCombCrvFactory: public CATBaseUnknown
{
  CATDeclareInterface;
  public:
   virtual HRESULT CreateCombinedCurve ( CATISpecObject *ipCurve1,
                                         CATISpecObject *ipDirection1,
                                         CATISpecObject *ipCurve2,
                                         CATISpecObject *ipDirection2,
                                         CATISpecObject **opCombinedCurve ) = 0 ;
}

Do not hesitate to consult the Object Modeler documentation if you have trouble defining a new interface [4] (what to write in .h, .cpp and .tsrc files ).

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Implementing the Combined Curve Factory Interface

The object chosen as Combined Curve Factory extends the "CATPrtCont " late type. The following code extracted from CATEMmrCombCrvFactory.cpp declares that CATPrtCont is extended to implement the Combined Curve factory interface.

CATImplementClass ( CAAEMmrCombCrvFactory ,
                    DataExtension         ,
                    CATBaseUnknown        ,
                    CATPrtCont );

// Tie the implementation to its interface
// ---------------------------------------
#include "TIE_CAAIMmrCombCrvFactory.h" // needed to tie the implementation to its interface
TIE_CAAIMmrCombCrvFactory( CAAEMmrCombCrvFactory);

As usual, update your dictionary to declare that CATPrtCont implements CAAIMmrCombCrvFactory.

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Retrieving the Combined Curve's StartUp

To create a new Combined Curve Instance, all you need to do is to instantiate the Combined Curve StartUp. To do so, you first have to retrieve this StartUp. It has been stored in the Combined Curve Catalog file named CAAMmrCombinedCurveCatalog.CATfct [5].

Let's look at CATEMmrCombCrvFactory.cpp again to see how to retrieve the Combined Curve StartUp.

...
CATIContainer *piContainerOnThis = NULL;
HRESULT rc = QueryInterface( IID_CATIContainer , ( void**) &piContainerOnThis );
...

Then, the AccessCatalog global function opens the Combined Curve Catalog.

...
CATICatalog * piCombinedCurveCatalog = NULL;
CATUnicodeString StorageName = "CAAMmrCombinedCurveCatalog.CATfct";
CATUnicodeString ClientId = "SAMPLES";
rc = ::AccessCatalog( &StorageName, &ClientId, piContainerOnThis , 
                             &piCombinedCurveCatalog);
...

CATICatalog::RetrieveSU method finally retrieves the Combined Curve StartUp.

...
CATBaseUnknown *pCombinedCurveStartup = NULL;
CATUnicodeString StartupType = "CombinedCurve";

piCombinedCurveCatalog->RetrieveSU( &pCombinedCurveStartup ,
                                    &StartupType ,
                                    "CATISpecObject" );
...

CATISpecObject *piSpecOnCombinedCurveStartup = NULL;
rc = pCombinedCurveStartup->QueryInterface( IID_CATISpecObject , 
                                        ( void**) &piSpecOnCombinedCurveStartup );

...

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Creating a Combined Curve Instance

The Combined Curve instance is created by instantiating the Combined Curve StartUp.

...

*opiSpecOnCombinedCurve = piSpecOnCombinedCurveStartup->Instanciate( NULL_string , 
                                                                              piContainerOnThis);

...

You have just created your first Combined Curve instance!

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Subscribing to repository for Configuration Data Storage

To define versioning on your mechanical feature [6], you have to initialize a data needed to store the software configuration on your feature.
This initialization is done calling the method "CreateConfigurationData" of CATMmrAlgoConfigServices class.

...

rc = CATMmrAlgoConfigServices::CreateConfigurationData(*opiSpecOnCombinedCurve);

...

Your feature can now be versioned! This means that its mechanical behaviors can be fixed for next software generation.

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Getting Feature Type Information for BackUp / StartUp management  - For Geometrical Features Only

BackUp / StartUp is a specific mode which occurs when something goes wrong with the CAAfeature (when startup catalog and code are not longer available on the runtime view) [7]

As Combined Curve is a geometrical feature deriving from GeometricalElement3D, you need to define and store its type according to CATIInputDescription implementation. This information, stored on the instance, will be useful in BackUpStartUp Mode to determine which behaviors are authorized.

This operation is done after instantiation, calling CATMmrFeatureAttributes::SetFeatureType 

...
CATIInputDescription* pInputDescriptionOnCombinedCurve = NULL;
rc = (*opiSpecOnCombinedCurve)->QueryInterface( IID_CATIInputDescription, (void**) &pInputDescriptionOnCombinedCurve);

...

CATIInputDescription::FeatureType Feature_type = CATIInputDescription::FeatureType_Unset;
rc = pInputDescriptionOnCombinedCurve -> GetFeatureType(Feature_type);

...

rc = CATMmrFeatureAttributes::SetFeatureType(*opiSpecOnCombinedCurve, Feature_type);
...

You have now defined the feature type of your Combined Curve! Let's now valuate this instance!

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Setting Default Values for the Instance Attributes

The attributes of this newly Combined Curve Instance are still empty. The interface of type for Combined Curve (CAAIMmrCombinedCurve) has methods to fill in the Combined Curve instance's attributes.

...

CAAIMmrCombinedCurve *piCombinedCurve = NULL;
rc = (*opiSpecOnCombinedCurve)->QueryInterface( IID_CAAIMmrCombinedCurve, 
                                                (void**) &piCombinedCurve );
...
    
piCombinedCurve->SetCurve    ( 1 , ipiSpecOnCurve1     );
piCombinedCurve->SetDirection( 1 , ipiSpecOnDirection1 );
piCombinedCurve->SetCurve    ( 2 , ipiSpecOnCurve2     );
piCombinedCurve->SetDirection( 2 , ipiSpecOnDirection2 );   
...

A complete documentation of this Interface is available [3].

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In Short

This use case has demonstrated how to create Combined Curve Instances by instantiating the Combined Curve StartUp retrieved in the Combined Curve StartUp Catalog file.

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References

History

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