LRasterPaint::RegionEllipse

#include "Ltwrappr.h"

L_INT LRasterPaint::RegionEllipse(UserDC, prcRect, phDestRgn)

Creates an elliptical region using the bounding rectangle, specified in prcRect.

Parameters

HDC UserDC

Handle to a device context, such as a screen, to use as a display surface. This parameter can also be NULL. The mapping mode of the device context must be MM_TEXT.

LPRECT prcRect

Pointer to a RECT structure that specifies the region boundaries

pHRGN phDestRgn

Pointer to the region handle to be updated with the resulting region.

Returns

Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes

Comments

The region creation procedure will be carried out using the current region properties. To determine the current region properties, call LRasterPaint::GetProperty. To set or change the current region properties, call LRasterPaint::SetProperty. For more information on the region properties, refer to the PAINTREGION structure.

This function will also use the current painting transformation information when creating the new region. To get the current painting transformation information, call LRasterPaint::GetTransformation. To change or set the painting transformation information, call LRasterPaint::SetTransformation.

If the user has set a bitmap in the toolkit, using the function LRasterPaint::SetMetrics, then the toolkit will create the region for the bitmap. Otherwise, the toolkit will create the region for the specified device context.

Required DLLs and Libraries

See Also

Functions

Topics

Example

L_INT LRasterPaint_RegionEllipseExample( CWnd* pWnd, LBitmap* pBitmap, L_INT m_nZoomFactor, L_INT m_nHscroll, L_INT m_nVscroll) 
{ 
   L_INT          nRet; 
   LRasterPaint   rstp ; 
   CDC*           pDC = pWnd->GetDC( ) ; 
   RECT           rcView ; 
   PAINTXFORM     PntXForm ; 
   L_INT          nXOffset, nYOffset ; 
   HRGN           hRgn ;  
   RECT           rcRegionRect ; 
 
   /* Initiate the Paint toolkit */ 
   nRet = rstp.Initialize ( ); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   PntXForm.nZoom    = m_nZoomFactor;  
   PntXForm.nXOffset = m_nHscroll;  
   PntXForm.nYOffset = m_nVscroll;  
 
   /* Set the painting transformations to relfect a zoom-in by 3:1 */ 
   nRet = rstp.SetTransformation ( &PntXForm ) ;  
   if(nRet != SUCCESS) 
      return nRet; 
 
   /* set the painting rectangle */ 
   SetRect ( &rcView, 0, 0, pBitmap->GetWidth( ), pBitmap->GetHeight( ) ) ; 
 
   if ( m_nZoomFactor < 100 ) 
   { 
      nXOffset = - MulDiv ( m_nHscroll, 100, m_nZoomFactor ) ;   
      nYOffset = - MulDiv ( m_nVscroll, 100, m_nZoomFactor ) ; 
   } 
   else 
   { 
      nXOffset = - m_nHscroll ;   
      nYOffset = - m_nVscroll ; 
   } 
 
   OffsetRect ( &rcView, nXOffset, nYOffset ) ; 
 
   rcView.left   = MulDiv ( rcView.left,   m_nZoomFactor, 100 ) ; 
   rcView.top    = MulDiv ( rcView.top,    m_nZoomFactor, 100 ) ; 
   rcView.right  = MulDiv ( rcView.right,  m_nZoomFactor, 100 ) ; 
   rcView.bottom = MulDiv ( rcView.bottom, m_nZoomFactor, 100 ) ; 
 
   /* paint the bitmap */ 
   pBitmap->Paint()->SetDC( pDC->m_hDC ); 
   pBitmap->SetDstRect( &rcView ); 
   pBitmap->Paint()->PaintDC(); 
 
   /* Set the rectangle coordinates with respect to the DC dimensions*/ 
   /* Set the rectangle coordinates with respect to the DC dimensions*/ 
   SetRect ( &rcRegionRect, 10, 10, 110, 110 ) ; 
 
   /* Use the current region properties and the current painting */ 
   /* transformations to create an ellipse region */ 
   nRet = rstp.RegionEllipse ( pDC->m_hDC, &rcRegionRect, &hRgn ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   /* Display the resulted region */ 
   FrameRgn ( pDC->m_hDC, hRgn, ( HBRUSH ) GetStockObject ( BLACK_BRUSH ), 1, 1 ) ; 
 
   /* Release the device context */ 
   pWnd->ReleaseDC( pDC ) ; 
 
   pBitmap->Paint( )->SetDC(NULL); 
 
  /* Delete the region */ 
   DeleteObject ( hRgn ) ; 
 
   /* Free the paint tools handle */ 
   nRet = rstp.Free ( ) ; 
   if(nRet != SUCCESS) 
      return nRet; 
 
   return SUCCESS ; 
} 
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