Character Data Size (UI)

The value of the Character Data Size should equal the sum of the sizes of the Character Data Size, Glyph ID, and TrueType Glyph Data fields. This value alerts the PCL interpreter when a continuation block is needed. The minimum possible value is 4. The value of Character Data Size plus Descriptor Size plus 4 (for the Format, Continuation, Reserved and Checksum bytes) will never be less than the value # given in the character download command. If the sum is exactly equal to #, then no continuation block is to be expected for the given character. However, if the sum exceeds #, then a continuation block is needed. A condition for the validity of a downloaded scalable TrueType character is that the sum of the # values for all of that character’s data blocks equals the sum of the Descriptor Size and Character Data Size and 2 (for Reserved and Checksum), plus 2 times the number of character data blocks (for Format and Continuation bytes).

Glyph ID (UI)

This field is used by the TrueType font scaler as an ID number for the glyph data associated with the given character.

TrueType Glyph Data

This field contains the data segment associated with the given character as found in the glyf table of the original TrueType font file. See the description in True Type Font Files.

Checksum (UB)

The value of this byte, when added to the sum of all of the bytes in the Character Data Size, Glyph ID, and TrueType Glyph Data fields, should equal 0 in modulo 256 arithmetic. The Checksum is found only in the last character data block associated with a given character.

EN

Character Descriptor Formats 11-69

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HP 5961-0509 manual Character Data Size UI, Glyph ID UI, TrueType Glyph Data, Checksum UB