Byte ; Data - Page 87

2001/10/02 

CHAPTER 2 "PCL" - 67 

[TrueType scalable font]  

<TrueType character descriptor> 

Byte 

Data 

0-1 

Format (15) 

Continuation (0) 

2 - 3 

Descriptor size 

Class (15) 

4 ~ 

Additional descriptor size 

2 + Desc.size 

Character Data Size 

4 + Desc. size 

Glyph ID 

6 + Desc. size 

TrueType Glyph Data 

0-1 

Format (15) 

Continuation (0) 

2 - 3 

Descriptor size 

Class (15) 

4 ~ 

Additional descriptor size 

2 + Desc.size 

Character Data Size 

4 + Desc. size 

Glyph ID 

6 + Desc. size 

beginning of TrueType Glyph Data 

0-1 

Format (15) 

Continuation (1) 

TrueType Glyph Data 
 
 
 

Last-2 

Reserved 

Checksum 

• 

The character data follows these header bytes. Characters are represented as raster data and the data bytes 

are used to build up an image of the character from left to right and from top to bottom, according to the 
character width and height settings. 

• 

Format (UB) - 15 specifies TrueType font.  

• 

Continuation (B) - specifies whether the character data represents a new character (0) or is a continuation of 

the character described by the previous character descriptor block (non-zero).  If the continuation byte is non-
zero the bytes following it are interpreted as character data. 

• 

Descriptor size (UB) - specifies the character descriptor size in bytes. 

• 

Class (UB) - indicates the character format. 

Value 

Class 

1 

Bitmap 

2 

Compressed Bitmap 

3 

Contour (Intellifont scalable) 

4 

Compound Contour (Intellifont scalable) 

15 

TrueType scalable  

• 

Character data size (UI) - should be the same value as (the character data size + Glyph ID + TrueType Glyph 

data) size. 

• 

Glyph ID (UI) - specifies the ID number for glyph data,  which is used by the TrueType font scaler. 

• 

TrueType Glyph data - includes the data segment which is associated with the given character as found in the 

glyph table of the original TrueType font file. 

• 

Checksum (UB) - should be a value which, when added to  "Character data + Glyph ID + TrueType Glyph 

data" size, produces a zero result.