2.2.27 UniversalFontId Object

The UniversalFontId object defines a mechanism for identifying fonts in EMF metafiles.

0	1	2	3	4	5	6	7	8	9	1 0	1	2	3	4	5	6	7	8	9	2 0	1	2	3	4	5	6	7	8	9	3 0	1
Checksum
Index

Checksum (4 bytes): An unsigned integer that is the checksum of the font. The checksum value has the following meanings.

Value	Meaning
0x00000000	The object is a device font.
0x00000001	The object is a Type 1 font that has been installed on the client machine and is enumerated by the PostScript printer driver as a device font.
0x00000002	The object is not a font but is a Type 1 rasterizer.
3 ≤ value	The object is a bitmap, vector, or TrueType font, or a Type 1 rasterized font that was created by a Type 1 rasterizer.  A checksum value SHOULD be computed for the font and compared to the value in this field. If it matches, it is considered to be the same as the font referenced by this metafile record. If it does not match, the system font mapper MAY use a default mechanism to select a back-up font.<55>

If a checksum value is computed, it SHOULD be computed using the following algorithm.

For the purpose of this computation, the font is considered simply to be a stream of bytes that is external to this EMF record. Any larger file structure in which the font might reside is system-dependent or implementation-dependent.

 ULONG ComputeFileviewCheckSum(PVOID pvView, ULONG cjView)
 {
     ULONG sum;
     PULONG pulCur,pulEnd;
  
     pulCur = (PULONG) pvView;
  
     for (sum = 0, pulEnd = pulCur + cjView / sizeof(ULONG); 
         pulCur < pulEnd; pulCur += 1)
     {
         sum += 256 * sum + *pulCur;
     }
     return ( sum < 2 ) ? 2 : sum;
 }

pvView: A pointer to the start of the font.

cjView: The length of the font in bytes.

Index (4 bytes): An unsigned integer that is an index associated with the font object. The meaning of this field is determined by the type of font.