LPaint::PaintRgnDCBuffer

#include "ltwrappr.h"

virtual L_INT LPaint::PaintRgnDCBuffer(LBuff, nRow, nCount=1, uROP3=SRCCOPY)

LBuffer& LBuff;	/* an LBuffer object */
L_INT nRow;	/* first row to paint */
L_INT nCount;	/* number of rows to paint */
L_UINT32 uROP3;	/* windows ROP code for display */

Paints image data into a device context from a buffer. This function works the same as LPaint::PaintDCBuffer, except that only the bitmap region is painted.

Parameter	Description
LBuff	A LEAD buffer of type LBuffer that contains the image data to paint.
nRow	The first row to paint. The painted portion of any row may be limited by the bitmap object rectangles.
nCount	The number of rows to paint. The painted portion of any row may be limited by the bitmap object rectangles.
uROP3	The Windows ROP code that determines how the destination rectangle is updated. This parameter takes the same codes as the Windows BitBlt() function. For ordinary painting, use SRCCOPY.

Returns

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

Comments

The bitmap must be allocated before you can create a region for it. Therefore, if you use this function in a paint-while-load routine, you must use your callback function to create the region after the bitmap is allocated.

The LBuff parameter is passed by reference, and is a required parameter.

Required DLLs and Libraries

LTDIS

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

See Also

Functions:	Class Members, LBitmapBase::RectToBitmap, LBitmapBase::RectFromBitmap
Topics:	Raster Image Functions: Displaying Images
	Raster Image Functions: Palettes
	Defining and Using a Bitmap Region
	Handling Palette Changes

Example

L_VOID TestPaintRgnBuffer(LBitmapBase& LeadBitmap,HDC hDC)
{
   LPaint LeadPaint(&LeadBitmap,hDC);
   LBitmapRgn LeadRegion;
   L_INT i,nBytesPerLine ;
   RECT Rect ;

   Rect.left = 10 ;
   Rect.top = 10 ;
   Rect.right = 50 ;
   Rect.bottom = 50 ;

   LeadRegion.SetBitmap(&LeadBitmap) ;
   LeadRegion.SetRgnRect(&Rect);

   nBytesPerLine = LeadBitmap.GetBytesPerLine() ;
   LBuffer  LeadBuffer((DWORD)nBytesPerLine);

   for (i=0;i<LeadBitmap.GetHeight();i++)
   {
      LeadBitmap.GetRow(&LeadBuffer,i) ;
      LeadPaint.PaintRgnDCBuffer(LeadBuffer,i) ;
   }
}