AccuSoft Resource Center

• Preparing the Compiler
• Add the Code
• Running the Application

1. To create the application interface, start Visual C++. The Visual C++ environment will appear.
    
2. Create a new MFC AppWizard project. For this tutorial, the project will be called IGTutorial (see below.)
   
   
   
   
3. In the MFC AppWizard – Step 1 dialog, click Single document to specify the type of application being created (see below).
   
   
    
4. Once the application is created, set up the compiler to use ImageGear.

• From the Project menu, click Settings
• In the Project Settings dialog, click the C/C++ tab
• From the Category drop-down list, select Preprocessor
• In the Additional include directories text box, type the path to where ImageGear was installed—the default path is C:\Program Files\AccuSoft\ImageGear v14\Version\DLL\Include, where Version is the edition of ImageGear (Professional, Enterprise or MD) being used (see below).

Next, click the Link tab. From the Category drop-down list, click Input and make the following additional changes:

• In the Object/library modules text box, type igcore14d.lib
• In the Additional library path text box, type C:\Program Files\Accusoft\ImageGear v14\Version\DLL\Lib, where Version is the edition of ImageGear (Professional, Enterprise or MD) being used

5. Add Zoom In and Zoom Out items to the View menu. For this tutorial, the IDs for these two items are ID_ZIN and ID_ZOUT respectively (see below).
   
   
    
   

1. Add the ImageGear header-file #include statement and add a member to the CIGTutorialDoc class, by modifying the IGTutorialDoc.h file (add the lines shown in bold):
    
   #if _MSC_VER > 1000
   #pragma once
   #endif // _MSC_VER > 1000
    
   #include "gear.h"
    
   class CIGTutorialDoc : public CDocument
   {
   protected: // create from serialization only
        CIGTutorialDoc();
        DECLARE_DYNCREATE(CIGTutorialDoc)
    
   // Attributes
   public:
        HIGEAR hIGear;
    
   // Operations
   public:
    
   This provides access to the ImageGear functions for use in our application. It also creates an ImageGear handle that will be used to hold the image it loaded and will be passed to the different ImageGear functions that are called.
    
2. Next, add code to the constructor and destructor of the CIGTutorial class, by modifying the IGTutorialDoc.cpp file (add the lines shown in bold):
    
   /////////////////////////////////////////////////////////////////////////////
   // CIGTutorialDoc construction/destruction
    
   CIGTutorialDoc::CIGTutorialDoc()
   :hIGear(NULL)
   {
        // TODO: add one-time construction code here
   }
    
   CIGTutorialDoc::~CIGTutorialDoc()
   {
        if (IG_image_is_valid( hIGear ))
             IG_image_delete( hIGear );
   }
    
   The code above includes the following ImageGear functions:

	IG_image_is_valid	This function is called to determine if the HIGEAR variable hIGear contains a handle of a valid ImageGear image.
	IG_image_delete	This function removes the HIGEAR handle of hIGear and frees the memory of the associated HIGEAR function. The function also frees the memory associated with the image’s DIB, if ImageGear allocated the DIB memory. If not, the DIB continues to exist and it becomes the responsibility of your application to free this memory when it is no longer required.

3. Use the Wizard Bar to add a virtual function named OnOpenDocument to the CIGTutorialDoc class. Replace the TODO comment with the following code in that function (add the lines shown in bold):
    
   /////////////////////////////////////////////////////////////////////////////
   // CIGTutorialDoc commands
    
   BOOL CIGTutorialDoc::OnOpenDocument(LPCTSTR lpszPathName)
   {
         if (!CDocument::OnOpenDocument(lpszPathName))
              return FALSE;
   
         if ( IG_load_file( (char*) lpszPathName, &hIGear ) == 0 )
             return TRUE;
         else
         {
               // ErrorReport should go here
               return FALSE;
          }
   }
   
   The code above includes the following ImageGear function:

IG_load_file

This function loads the specified file into the HIGEAR.

4. Use the Wizard Bar to add three public member functions to the CIGTutorialDoc class. The code for the three functions is as follows (add the lines shown in bold):
    
   AT_ERRCOUNT CIGTutorialDoc::dsplZoomSet(CView *v, AT_MODE nZoomMode, DOUBLE dHZoom, DOUBLE dVZoom)
   {
        DWORD dwGrpID = 0;
        AT_ERRCOUNT nErrCount;
    
        nErrCount = IG_dspl_zoom_set( hIGear, dwGrpID, nZoomMode, dHZoom, dVZoom );
            if ( nErrCount != NULL )
            {
                   // ErrorReport should go here
             }
            return nErrCount;
   }
    
   AT_ERRCOUNT CIGTutorialDoc::dsplZoomGet(CView *v, LPAT_MODE lpnZoomMode, LPDOUBLE lpdHZoom, LPDOUBLE lpdVZoom)
   {
             DWORD dwGrpID = 0;
             AT_ERRCOUNT nErrCount;
    
              nErrCount = IG_dspl_zoom_get( hIGear, dwGrpID, v->GetSafeHwnd(), lpnZoomMode, lpdHZoom, lpdVZoom );
             if ( nErrCount != NULL )
              {
                     // ErrorReport should go here
               }
                return nErrCount;
   }
    
   void CIGTutorialDoc::DrawImage(CView *v, CDC *dc, CPrintInfo *pInfo)
   {
             if ( IG_image_is_valid( hIGear ))
             {
             DWORD dwGrpID = 0;
             POINT p;
             SIZE s;
             DWORD nMapMode;
             AT_RECTANGLE Viewport;
             AT_RECTANGLE Window;
    
             // get current mapping parameters
             nMapMode = ::GetMapMode( dc->m_hDC );
    
             ::GetViewportOrgEx( dc->m_hDC, &p );
             Viewport.x = p.x;
             Viewport.y = p.y;
    
             ::GetViewportExtEx( dc->m_hDC, &s );
             Viewport.width = s.cx;
             Viewport.height = s.cy;
    
             ::GetWindowOrgEx( dc->m_hDC, &p );
             Window.x = p.x;
             Window.y = p.y;
    
             ::GetWindowExtEx( dc->m_hDC, &s );
             Window.width = s.cx;
             Window.height = s.cy;
    
             IG_dspl_mapmode_set( hIGear, dwGrpID,
                       nMapMode, &Viewport, &Window );
             IG_dspl_image_draw( hIGear, dwGrpID,
                       v->GetSafeHwnd(), dc->GetSafeHdc(), NULL );
             }
   }

The code above includes the following ImageGear functions:

	IG_dspl_mapmode_set	This function sets the current map mode and logical coordinate system.
	IG_dspl_image_draw	This function draws and image onto a destination device context.
	IG_dspl_zoom_set	This function sets the current zoom value.
	IG_dspl_zoom_get	This function gets the current zoom value.

5. Next, add the following code to the OnDraw() method of the CIGTutorialView class (add the lines shown in bold):
    
   /////////////////////////////////////////////////////////////////////////////
   // CIGTutorialView drawing
    
   void CIGTutorialView::OnDraw(CDC* pDC)
   {
             CIGTutorialDoc* pDoc = GetDocument();
             ASSERT_VALID(pDoc);
             // TODO: add draw code for native data here
    
             pDoc->DrawImage( this, pDC, NULL );
   }
    
   The above code calls the DrawImage function defined in IGTutorialDoc.cpp and ensures that the image will be properly drawn when the window is redrawn.

Use the Wizard Bar to add command message handlers for the ID_ZIN and ID_ZOUT messages to CIGTutorialView. Then, add the following code to the message handler functions (add the lines shown in bold):
 
/////////////////////////////////////////////////////////////////////////////
// CIGTutorialView message handlers
 
void CIGTutorialView::OnZin()
{
          DOUBLE dHZoom, dVZoom;
          CIGTutorialDoc* pDoc = GetDocument();
          ASSERT_VALID( pDoc );
          pDoc->dsplZoomGet( this, NULL, &dHZoom ,&dVZoom );
          dHZoom *= 1.25;
          dVZoom *= 1.25;
          pDoc->dsplZoomSet( this,
                    IG_DSPL_ZOOM_H_FIXED | IG_DSPL_ZOOM_V_FIXED, dHZoom, dVZoom );
          InvalidateRect( NULL, FALSE );
          UpdateWindow();
}
 
void CIGTutorialView::OnZout()
{
          DOUBLE dHZoom, dVZoom;
          CIGTutorialDoc* pDoc = GetDocument();
          ASSERT_VALID( pDoc );
          pDoc->dsplZoomGet( this, NULL, &dHZoom ,&dVZoom );
          dHZoom /= 1.25;
          dVZoom /= 1.25;
          pDoc->dsplZoomSet( this,
                    IG_DSPL_ZOOM_H_FIXED | IG_DSPL_ZOOM_V_FIXED, dHZoom, dVZoom );
          InvalidateRect( NULL, FALSE );
          UpdateWindow();
}
 
The code above zooms in and out respectfully, increasing/decreasing the image size in increments of 25%.

6. Finally, add the following code to the InitInstance() method of the CIGTutorialApp class (add the line shown in bold):
    
   /////////////////////////////////////////////////////////////////////////////
   // CIGTutorialApp initialization
    
   BOOL CIGTutorialApp::InitInstance()
   {
             AfxEnableControlContainer();
             .
             .
             .
             // Dispatch commands specified on the command line
             if (!ProcessShellCommand(cmdInfo))
                       return FALSE;
    
             IG_lic_solution_name_set( "AccuSoft 1-100-14" );
    
             // The one and only window has been initialized, so show and update it.
             m_pMainWnd->ShowWindow(SW_SHOW);
             m_pMainWnd->UpdateWindow();
    
             return TRUE;
   }

That's it! Simply compile and run the DLL project and you will have a simple, yet functional image viewer. Add the plug-ins to enable support for over 100 image formats.