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L_ConvertToDIB

Summary

Converts a LEAD Technologies bitmap into a Windows device independent bitmap (DIB). When this function is completed, there are two copies of the image in memory: the DIB and the original LEAD bitmap. Freeing one will not affect the other.

Syntax

#include "l_bitmap.h"

L_LTKRN_API L_HDIB L_ConvertToDIB(pBitmap, uType)

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle referencing the bitmap to change.

L_UINT uType

Flag that indicates the type of DIB to create. Possible values are:

Value	Meaning
DIB_BITMAPINFOHEADER	[0] DIB that uses a BITMAPINFOHEADER
DIB_BITMAPV4HEADER	[1] DIB that uses a BITMAPV4HEADER. (Introduced in Windows 95 and Windows NT 4.0)
DIB_BITMAPV5HEADER	[2] DIB that uses a BITMAPV5HEADER (Introduced in Windows 2000 and Windows 98)

Returns

This function will return a handle to a DIB.

Comments

This function allocates a DIB bitmap and copies the LEAD bitmap to the DIB.

A DIB consists of one of the following:

a BITMAPFILEHEADER,
a BITMAPV4HEADER (introduced in Windows 95 and Windows NT 4.0),
or a BITMAPV5HEADER (introduced in Windows 2000 and Windows 98),

followed by a color table and then the bitmap data. The resulting DIB type is determined by the value of the uType flag.

The orientation of the image and color order will depend on how the image was loaded into the LEAD bitmap.

If you want to load another image using the same bitmap handle, you must initialize the bitmap handle again.

When you no longer need the DIB, you can free it using the Windows GlobalFree function.

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, Linux.

Example

For complete sample code, refer to the DIBDDB
example.
This example takes a LEAD bitmap, converts it to a V5 DIB and writes
out the DIB as a bitmap file

#include <fcntl.h> 
 
static L_INT MySaveFile(HGLOBAL      hDIB, 
                        L_TCHAR*     pszFileName) 
{ 
   DWORD             dwSize; 
   HANDLE            fp; 
   L_UCHAR*          pDIB; 
   BITMAPFILEHEADER  bfh; 
   PBITMAPINFOHEADER pbih; 
   L_SIZE_T          zDIBsize; 
 
   zDIBsize = GlobalSize(hDIB); 
 
   bfh.bfType        = 0x4d42; //"BM"; 
   bfh.bfSize        = (DWORD) (sizeof(BITMAPFILEHEADER) + zDIBsize); 
   bfh.bfReserved1   = 0; 
   bfh.bfReserved2   = 0; 
 
   pDIB = (L_UCHAR *)GlobalLock(hDIB); 
   pbih = (PBITMAPINFOHEADER)pDIB; 
 
   // Compute the offset to the array of color indices.  
   bfh.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) +  
                    pbih->biSize + pbih->biClrUsed  * sizeof (RGBQUAD);  
 
   fp = CreateFile(pszFileName, GENERIC_WRITE | GENERIC_READ , 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0); 
 
   if (fp == 0) 
      return FALSE; 
 
   WriteFile(fp, &bfh, sizeof(BITMAPFILEHEADER), &dwSize, NULL); 
   WriteFile(fp, pDIB, (L_UINT) zDIBsize, &dwSize, NULL); 
   CloseHandle(fp); 
 
   GlobalUnlock(hDIB); 
   return TRUE; 
} 
 
L_INT ConvertToDIBExample(pBITMAPHANDLE pBitmap,L_TCHAR* pszFileName) 
{ 
   HGLOBAL hDIB; 
   hDIB = L_ConvertToDIB(pBitmap, DIB_BITMAPINFOHEADER); 
   MySaveFile(hDIB, pszFileName); 
   GlobalFree(hDIB); 
   return SUCCESS; 
}