HP Pcl 5 Manual

							ENCharacter Code Command 11-49
Character Code Command 
The Character Code command establishes the decimal code that is 
associated with the next character downloaded. This value is used to 
reference the character for printing.
E
C * c # E
# =character code 
Default =0
Range =0 - 65535
NotesFor unbound fonts, the character code for a given character equals its 
symbol index value. 
For TrueType fonts, a special code must be used to download glyphs 
which never stand alone as characters. FFFF (hex) should be used 
for this purpose. 
Example 
To designate the character code for an ASCII lower-case “p”, send:
E
C*c112E 
						

							11-50   Soft Font CreationEN
Character Definition Command 
The Character Descriptor and Data command is used to download 
character data blocks to the printer for both bitmap and scalable fonts.
E
C ( s # W   [character descriptor and data] 
Default =N/A
Range =0 - 32767
The value field (#) identifies the number of bytes in the immediately 
following character data block. The maximum number is 32767.
For a detailed description of the Character Descriptor fields for bitmap 
fonts refer to Character Descriptor and Data Format for PCL Bitmap 
Fonts. For Intellifont scalables, refer to “Character Descriptor and 
Data Format for Intellifont Scalable Fonts.” For TrueType fonts, refer 
to “Character Descriptor and Data Format for TrueType Fonts.”
NoteExamples for defining a bitmapped portrait and landscape character 
are provided under Character Definition Examples, after the 
Character Descriptor Formats section, later in this chapter. 
						

							ENCharacter Descriptor Formats 11-51
Character Descriptor Formats 
Character definition formats for PCL Bitmap, Intellifont Scalable 
and TrueType Scalable fonts are shown on the following pages.
NoteThe following notation is used to define the data type of each field in 
the character descriptors.
Character Descriptor and Data Format for PCL 
Bitmap Fonts    
The descriptor of a PCL bitmap character is at least 14 bytes long and 
contains information such as the character’s width and height.
The character data is binary (raster) data that identifies the shape of 
the character.
Table 11-35 shows the format of the bitmap character descriptor and 
data. Table 11-34 Character Descriptors/Data Continuation Block
(B) : Boolean (0,1)
(UB) : Unsigned Byte (0 . . 255)
(SB) : Signed Byte (-128 . . 127)
(UI) : Unsigned Integer (0 . . 65535)
(SI) : Signed Integer (-32768 . . 32767)
Table 11-35 PCL Bitmap Character Descriptor
and Data Format
Byte  15 (MSB)                          8 7                                      (LSB) 0
0  Format (4) Continuation (0)
2  Descriptor Size (14) Class (1)
4 Orientation Reserved (0) 
						

							11-52   Soft Font CreationEN
Format (UB)  
This is the first byte of every character data block header. It specifies 
the format of the character descriptor and data. The format number 
used for bitmap fonts is 4. This format must match that of the Font 
Header.
If the format number is different from that expected by the device, the 
character is discarded.6 Left Offset
8 Top Offset
10 Character Width
12 Character Height
14 Delta X
16  Raster Character Data: (in bytes)
M
Table 11-36 PCL Bitmap Continuation Character Descriptor and 
Data Format
Byte  15 (MSB)                          8 7                                      (LSB) 0
0  Format (4)  Continuation (non-zero)
2  Raster Character Data: (in bytes)
M
Table 11-37
Value Format
4 LaserJet Family (Raster)
10* Intellifont Scalable
15* TrueType Scalable
 * These are described later in this chapter. Table 11-35 PCL Bitmap Character Descriptor
and Data Format (continued) 
						

							ENCharacter Descriptor Formats 11-53
Continuation (B)
This is the second (and last) byte of every character data block 
header. It specifies whether the following data is the first (0) data 
block of a new character definition, or a continuation (1) block for a 
character definition which has already been received by the printer. 
Because the value field in a Character Definition command is limited 
to 32767 bytes, characters whose byte count exceed this must be 
sent in two or more blocks.
Descriptor Size (UB)
This is the first byte of the character descriptor. It specifies the size 
of the character descriptor in bytes. The descriptor size used by the 
HP LaserJet printer family for bitmap fonts is 14.
Class (UB)     
Specifies the format of the character data. For bitmap fonts only 
values 1 and 2 are used, as described below.
Table 11-38
Value Class
1Bitmap
2 Compressed Bitmap
3* Contour (Intellifont Scalable)
4*  Compound Contour (Intellifont Scalable)
15* TrueType Scalable
* These are described later in this chapter. 
						

							11-54   Soft Font CreationEN
Class 1 - Bitmap Data
Class 1 or bitmap (raster) character data is a string of bytes 
containing the dot-per-bit image of the character, no data 
compression. If a bit is set to one, the corresponding dot is printed. 
The data is grouped in dot rows. A row describes a one-dot-high strip 
of the character from left to right, in the direction of the printer’s raster 
scan (see the Portrait Bitmap Character Data Example, at the end of 
this chapter). Zeroed bits must be added to the end of each row to 
make it contain an integral number of bytes. The dot rows are 
organized from top to bottom of the character. For example, the first 
dot row of data corresponds to the top dot row of the character.
The number of bytes of the character data should be exactly 
Character Width (in bytes) times Character Height. If more 
data is received, it is discarded; if less data is received, the character 
consists of only the data downloaded.
Class 2 - Compressed Bitmap Data
For a compressed bitmap character, the data is composed of a string 
of bytes using a run-length encoding with line repetition compressed 
format (see Figure 11-2). The first byte indicates the number of times 
the first raster row is repeated after its initial occurrence. It is 
assumed that the first pixel in a row is white, hence the second byte 
indicates how many white pixels start the row. The third byte indicates 
how many black pixels, the fourth byte indicates the number of white 
pixels again, etc. If the first pixel in a row is black, the white pixel 
indicator (the second byte) is 0. If there are more than 255 pixels in a 
row of the same type, there is a byte containing 255, followed by a 0 
byte, followed by a byte containing the count of remaining pixels of 
the current type.
The width of each row is determined by the character width (in dots) 
as specified in the character descriptor for the character. The pixel 
count (number of 1’s and 0’s bits) for each row in the character cell 
must equal the character width. For example, in Figure 11-5, the cell 
width is 20, thus each row (excluding the repetition count byte) adds 
up to 20.
Once the row has been filled, the row is duplicated as indicated in its 
first byte, then a new row is started. 
						

							ENCharacter Descriptor Formats 11-55 Figure 11-5 Class 2 Character Data 
						

							11-56   Soft Font CreationEN
Orientation (UB)
Orientation byte specifies the orientation of the character. The 
orientation of the character must match the orientation of the font.
If the orientation is not supported or is different from the orientation 
specified in the font header, the character is discarded.
Left Offset (SI)
Left offset specifies the distance in dots from the reference point to 
the left side of the character pattern on the physical page coordinate 
system (this value is orientation dependent). The left and top offsets 
locate the character reference point about the cursor position (see 
Figure 11-6 and Figure 11-7).
PCL 5 printers support kerning (both negative left and right side 
bearings) of both fixed-pitch and propor tionally-spaced fonts. Note 
that large offsets could place the character off the printable area of 
the page causing the character to be clipped.
The legal range for the left offset is –16384 to 16384 dots.
Top Offset (SI)
Top offset specifies the distance in dots from the reference point to 
the top of the character pattern on the physical coordinate system 
(this value is orientation dependent.) The left and top offsets locate 
the character reference point about the cursor position (see Figure 
11-6 and Figure 11-7). The legal range for the top offset is –16384 
to 16384 dots. Table 11-39
Value Orientation
0 Portrait
1 Landscape
2 Reverse portrait
3 Reverse landscape 
						

							ENCharacter Descriptor Formats 11-57
Character Width (UI)
The Character Width, used for bitmap fonts only, identifies the width 
of the character in dots on the physical coordinate system. Generally, 
this width is from the farthest left black dot to the farthest right black 
dot. Character width is orientation dependent.
The legal range for character width is 1 to 16384 dots.
Character Height (UI)
Character Height specifies the height of the character in dots on 
the physical coordinate system. Character height is orientation 
dependent.
The legal range for character height is 1 to 16384 dots.
Delta X (SI)     
Delta X specifies the number of quarter dots (radix dots) by which 
the horizontal position within the logical page coordinate system is 
incremented after printing the character. This value is only used by 
the printer when the font is proportionally spaced.
The legal range for delta X is –32768 to 32767 quarter units.
Character Data    
Character data is a string of bytes containing the dot-per-bit image of 
the character or a run-length encoding with line repetition 
compressed format. 
						

							11-58   Soft Font CreationEN
Figure 11-6 Portrait Character Example