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Creating Stub Implementation of Your Adaptor Class

To create a stub implementation of your adaptor class, follow this procedure:

  1. Add a C++ header file to the adaptor C++ project. This header file will hold the definition of your adaptor class. You can give your class any name. This example uses the following naming convention:

    vendor_name + adaptor
    

    For this example, the header file that contains the adaptor class definition is named MyDeviceAdaptor.h.

  2. Copy the following class definition into the header file. This adaptor class contains all the virtual functions defined by the IAdaptor abstract class.

    #include "mwadaptorimaq.h" // required header
    
    class MyDeviceAdaptor : public imaqkit::IAdaptor {
    
    public:
    
       // Constructor and Destructor
       MyDeviceAdaptor(imaqkit::IEngine* engine, const
                       imaqkit::IDeviceInfo* deviceInfo,
                       const char* formatName);
    
       virtual ~MyDeviceAdaptor();
    
       // Adaptor and Image Information Functions
       virtual const char* getDriverDescription() const;
       virtual const char* getDriverVersion() const; 
       virtual int getMaxWidth() const;
       virtual int getMaxHeight() const;
       virtual int getNumberOfBands() const; 
       virtual imaqkit::frametypes::FRAMETYPE getFrameType() const;
    
       // Image Acquisition Functions
       virtual bool openDevice();
       virtual bool closeDevice(); 
       virtual bool startCapture();
       virtual bool stopCapture();
    
    };
    
  3. Add a C++ source file to the adaptor project. You can give the source file any name. This example names the file mydeviceadaptor.cpp.

  4. Copy the following stub implementations of all the adaptor virtual functions into the C++ source file.

    #include "MyDeviceAdaptor.h"
    #include "mwadaptorimaq.h"
    
    // Class constructor
    MyDeviceAdaptor::MyDeviceAdaptor(imaqkit::IEngine* engine, 
                             imaqkit::IDeviceInfo* deviceInfo,
    		  const char* formatName):imaqkit::IAdaptor(engine){
    }
    
    // Class destructor
    MyDeviceAdaptor::~MyDeviceAdaptor(){ 
    }
    
    // Device driver information functions
    const char* MyDeviceAdaptor::getDriverDescription() const{ 
    	return "MyDevice_Driver";
    }
    const char* MyDeviceAdaptor::getDriverVersion() const { 
    	return "1.0.0";
    } 
    
    // Image data information functions
    int MyDeviceAdaptor::getMaxWidth() const { return 640;}
    int MyDeviceAdaptor::getMaxHeight() const { return 480;}
    int MyDeviceAdaptor::getNumberOfBands() const { return 1;}
    
    imaqkit::frametypes::FRAMETYPE MyDeviceAdaptor::getFrameType()
                  const { 
        return imaqkit::frametypes::MONO8; 
    }
    
    // Image acquisition functions
    bool MyDeviceAdaptor::openDevice() {return true;}
    bool MyDeviceAdaptor::closeDevice(){return true;} 
    bool MyDeviceAdaptor::startCapture(){return true;}
    bool MyDeviceAdaptor::stopCapture(){return true;}
    
  5. Add a reference to your adaptor class header file to the file containing the exported functions, mydevice_exported_fcns.cpp, that you created in Using Adaptor Exported Functions. This is needed because the createInstance() exported function instantiates an object of this class.

    #include "MyDeviceAdaptor.h"
    
  6. Edit the stub implementations of the createInstance() function, also in the exported functions source file, mydevice_exported_fcns.cpp. Make the function instantiate an object of your adaptor class, highlighted in italics below. (In the stub, it returns NULL.)

    void getDeviceAttributes(const imaqkit::IDeviceInfo* deviceInfo,
    										 const char* formatName,
    						   imaqkit::IPropFactory* devicePropFact,
    					  imaqkit::IVideoSourceInfo* sourceContainer,
    						   imaqkit::ITriggerInfo* hwTriggerInfo){
    
       // Create a video source
      sourceContainer->addAdaptorSource("MyDeviceSource", 1);
    }
    
    imaqkit::IAdaptor* createInstance(imaqkit::IEngine* engine,
    						  imaqkit::IDeviceInfo* deviceInfo,
    										 char* formatName){
    	
    	imaqkit::IAdaptor* adaptor = new
                      MyDeviceAdaptor(engine,deviceInfo,formatName);
    
        return  adaptor;
    }
    
  7. Build the adaptor DLL. Select the Build Solution option on the Build menu.

  8. Start the MATLAB® software.

  9. Call the imaqhwinfo function. Note how the adaptor, named mydeviceimaq, is included in the list of available adaptors returned by imaqhwinfo. If you have not previously registered your adaptor DLL, register your adaptor with the toolbox — see Registering an Adaptor with the Toolbox. To view more detailed information about your adaptor, call imaqhwinfo again with this syntax:

    dev_info = imaqhwinfo('mydeviceimaq');
    
  10. Create a video input object for the mydeviceimaq adaptor, using the videoinput function.

      Note   While you can create a video input object with your adaptor, you cannot use it to acquire video from a device. You must implement the adaptor class acquisition functions to do that. See Acquiring Image Data for more information.

    vid = videoinput('mydeviceimaq',1)
    
    Summary of Video Input Object Using 'MyDevice'.
    
       Acquisition Source(s): MyDeviceSource is available.
    
      Acquisition Parameters: 'MyDeviceSource' is the current selected source.
                             10 frames per trigger using the selected source.
                               '640x480' video data to be logged upon START.
                               Grabbing first of every 1 frame(s).
                               Log data to 'memory' on trigger.
    
          Trigger Parameters:  1 'immediate' trigger(s) on START.
    
                      Status:  Waiting for START.
                               0 frames acquired since starting.
                               0 frames available for GETDATA.
    
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