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FILEOVERLAYCALLBACKDATA

The FILEOVERLAYCALLBACKDATA structure passed to the OVERLAYCALLBACK function contains information about the overlay image found in the file. Some members of this structure are for input some are for output as follows:

Note: The LTFIL.H header file describes the entire FILEOVERLAYCALLBACKDATA structure.

Members

L_UINT uStructSize

Size of this structure. Use sizeof(FILEOVERLAYCALLBACKDATA)

L_TCHAR* pszFilename

(input) String containing the name of the file containing the overlay bitmap.

L_INT nPageNumber

(input) Page number of the requested overlay image.

L_BOOL bInfo

(input) Determines whether overlay image info or actual bitmap is needed as follows:

Value	Meaning
TRUE	Only the information about the overlay image is needed. You must now in the `nInfoWidth`, `nInfoHeight`, `nInfoXResolution` and `nInfoYResolution` members of this structure.
FALSE	The actual overlay bitmap is needed. You must now load the overlay bitmap into the `pLoadBitmap` member of this structure.

L_INT nInfoWidth

(output) Overlay image width in pixels. If the bInfo member of this structure is TRUE, you need to set this member to the overlay bitmap width, otherwise, ignore.

L_INT nInfoHeight

(output) Overlay image height in pixels. If the bInfo member of this structure is TRUE, you need to set this member to the overlay bitmap height, otherwise, ignore.

L_INT nInfoXResolution

(output) Overlay image horizontal resolution in pixels per inch. If the bInfo member of this structure is TRUE, you need to set this member to the overlay bitmap horizontal resolution, otherwise ignore.

L_INT nInfoYResolution

(output) Overlay image vertical resolution in pixels per inch. If the bInfo member of this structure is TRUE, you need to set this member to the overlay bitmap vertical resolution, otherwise ignore.

pBITMAPHANDLE pLoadBitmap

(output) Pointer to a BITMAPHANDLE structure into which the overlay bitmap will be loaded. If the bInfo member is FALSE, you need to load the overlay bitmap into this member. Otherwise ignore. You do not need to call L_FreeBitmap on this bitmap. LEADTOOLS will free it for you once its done overlaying it on the image.