Brother HL-1250, Technical Reference Manual

Page: 85 / 441

2001/10/02
CHAPTER 2 "PCL" - 65
<Bitmap continuation data>
Byte Data
0-1 Format Continuation
2 Raster Character Data
•
The bytes which follow the header are the raster data that make up the character.
•
Attributes are in one of four numerical formats.
Unsigned integer (UI) 0 to 65535
Signed integer (SI) –32768 to 32767
Unsigned byte (UB) 0 to 255
Boolean - 0 or 1
•
Format (UB) - 4 for bitmap fonts.
•
Continuation (B) - signifies whether the character data represents a new character (0) or is a continuation of
the character described by the previous character descriptor block and its data (non-zero). If the continuation
byte is non-zero the bytes following it are interpreted as character data.
•
Descriptor size (UB) - 14 for bitmap fonts.
•
Class (UB) - 1 for bitmap fonts, 2 for compressed bitmap fonts. Bitmap fonts are described using
uncompressed raster data. Compressed bitmap fonts character data is encoded as follows. The first byte of a
line of data contains the number of times that the line is successively repeated. The second byte indicates the
number of successive white pixels that start the line and the third byte indicates the number of successive
black pixels that follow the white pixels. Subsequent even and odd numbered bytes indicate the number of
successive white and black pixels respectively that make up the line. If there are more than 255 successive
pixels of a single color this is indicated by a byte set to 255 followed by a byte set to 0 followed by a byte
indicating the remaining number of pixels of that color. The width of each line is determined by the character
width attribute. All rows must contain the same number of pixels. The total number of pixels on each row must
equal the character width attribute.
•
Orientation (UB) - the orientation of the character. 0 = portrait, 1 = landscape, 2 = reverse portrait or 3 =
reverse landscape. This attribute setting must match the orientation specified in the font descriptor block.
•
Left offset (SI) - the distance between the character reference point and the leftmost dot of the character on
the grid. The offset can be from -16384 to 16383.
•
Top offset (SI) - the distance between the character reference point and the topmost dot of the character on
the grid. The offset can be from -16384 to 16383.
•
Character width (UI) - the width of the download character in grid dots. This can be in the range 1 to 16384.
•
Character height (UI) - the height of the download character in grid dots. This can be in the range 1 to 16384.
•
Delta X (UI) - the horizontal distance from the bottom left hand corner of the character’s grid that the cursor is
moved after the character is printed. The attribute is specified in units of 1/1200" and can be in the range -
32768 to 32767.
[Intellifont scalable font data]
Byte Data
0-1 Format Continuation
2 - 3 Descriptor size Class
4 - 5 Contour Character data
Last data Reserved Checksum