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LBitmapBase::SetDataPointer

#include "ltwrappr.h"

virtual L_INT LBitmapBase::SetDataPointer(pData, dwSize)

L_UCHAR *pData;	data pointer
L_UINT32 dwSize;	size of the data buffer pointed to by pData

Sets the data pointer for the bitmap to the specified data pointer pData.

Parameter	Description
pData	Data pointer used to set the bitmaps data pointer.
dwSize	Size of the data buffer pointed to by pData.

Returns

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

Comments

This function can be used to change the data pointer of a bitmap that was created by LBitmapBase::CreateBitmap, or allocated by LBitmapBase::Allocate, with memory type TYPE_USER. The data pointer to of the bitmap is set to the data pointer passed in through pData.

You are responsible for managing the image data. LBitmapBase::Free will not free pData.

The memory buffer pointed to by pData must be valid when the bitmap is being used. If you free a memory buffer that is referenced by a bitmap, you will get access violations when you try to use that bitmap.

If you pass NULL for pData, the bitmap has no bitmap data. You should not try to use a bitmap that has no data pointer.

Note: To calculate the correct size for a single row of image data:

(((Width * BitsPerPixel) + 31) >> 3)) &~3

Required DLLs and Libraries

LTKRN

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

Platforms

Win32, x64.

Example

#define BITMAP_WIDTH 256 
#define BITMAP_HEIGHT 256 
 
L_INT LBitmapBase__SetDataPointerExample(HWND hWnd) 
{ 
   UNREFERENCED_PARAMETER(hWnd); 
 
   L_INT nRet; 
   HGLOBAL hGlobal1, hGlobal2; 
   L_UCHAR *pBuffer1, *pBuffer2; 
   LBitmapBase BitmapBase;  
   //pBuffer1 points to raw data with 256 shades of red 
   //pBuffer2 points to raw data with 256 shades of green 
   hGlobal1 = GlobalAlloc(GMEM_MOVEABLE, BITMAP_WIDTH * BITMAP_HEIGHT * 3); 
   pBuffer1 = (L_UCHAR*)GlobalLock(hGlobal1);  
   hGlobal2 = GlobalAlloc(GMEM_MOVEABLE, BITMAP_WIDTH * BITMAP_HEIGHT * 3); 
   pBuffer2 = (L_UCHAR*)GlobalLock(hGlobal2);  
   L_INT iCol, iRow, iCounter;  
   iCounter = 0; 
   for(iCol = 0; iCol < BITMAP_WIDTH; iCol++) 
      for (iRow=0; iRow < BITMAP_HEIGHT; iRow++) 
      { 
         pBuffer1[iCounter + 0] = 0; //Blue 
         pBuffer1[iCounter + 1] = 0; //Green 
         pBuffer1[iCounter + 2] = (L_UCHAR)iCol; //Red  
         pBuffer2[iCounter + 0] = 0; //Blue 
         pBuffer2[iCounter + 1] = (L_UCHAR) iCol; //Green 
         pBuffer2[iCounter + 2] = 0; //Red  
         iCounter = iCounter + 3; 
      } 
      // this sets the image to be pBuffer1 
      nRet =BitmapBase.Create(  
            BITMAP_WIDTH,  
            BITMAP_HEIGHT,  
            24,  
            ORDER_BGR,  
            NULL,  
            TOP_LEFT,  
            TYPE_USER, 
            (L_UCHAR *)pBuffer1,  
            BITMAP_WIDTH * BITMAP_HEIGHT * 3); 
      if(nRet !=SUCCESS) 
         return nRet; 
 
   nRet =BitmapBase.Save(MAKE_IMAGE_PATH(TEXT("Test1.bmp")), FILE_BMP, 24,2,0,NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet =BitmapBase.SetDataPointer(pBuffer2, BITMAP_WIDTH * BITMAP_HEIGHT * 3); 
   if(nRet !=SUCCESS) 
      return nRet; 
   nRet =BitmapBase.Save(MAKE_IMAGE_PATH(TEXT("Test2.bmp")), FILE_BMP, 24,2,0,NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   return SUCCESS; 
}

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Functions:	LBitmapBase::Allocate, LBitmapBase::Create
Topics:	Raster Image Functions: Creating and Deleting Images