DATA_HEADER structure

The DATA_HEADER structure is used to specify a data section within a Unidrv font format file (.uff file).


typedef struct _DATA_HEADER {
  DWORD dwSignature;
  WORD  wSize;
  WORD  wDataID;
  DWORD dwDataSize;
  DWORD dwReserved;



Specifies the signature value identifying the type of data in the data section. Valid signature values are listed in the following table.

Signature Definition
DATA_CTT_SIG This data section contains CTT-formatted glyph set information.
DATA_GTT_SIG This data section contains GTT-formatted glyph set information.
DATA_IFI_SIG This data section contains IFI-formatted font metrics.
DATA_UFM_SIG This data section contains UFM-formatted font metrics.
DATA_VAR_SIG This data section contains data to be downloaded to the printer. See the following Remarks section.


Specifies the size, in bytes, of the DATA_HEADER structure.


If the data section contains font metrics data, this value must be a unique font identifier. For fonts that are permanently downloaded by the font installer, this value should be the downloaded font's identifier.

If the data section contains glyph data, this value must be a glyph set identifier.

If the data section contains variable data, this value must be zero.


Specifies the size, in bytes, of all the information represented by this DATA_HEADER structure. For example, if dwSignature is DATA_UFM_SIG, this value represents the size, in bytes, of the font's UNIFM_HDR structure and all associated structures. The size value does not include any byte padding required to align the next DATA_HEADER structure to a DWORD.


Not used. Must be set to zero.


If dwSignature is DATA_VAR_SIG, the data section contains variable data that Unidrv sends to the printer the first time the font is selected. Typically, this data consists of a font header and corresponding font identifier, along with downloadable glyph information for all the glyphs supported by the font. PCL soft font information includes printer control language commands for loading the font header and glyph definitions for all supported glyphs. Unidrv does not validate variable data. Data validation should be performed by the font installer.

Each DATA_HEADER structure must be DWORD-aligned.


Header prntfont.h (include Prntfont.h)

See Also