Graphic Orders
BLT2BB_SHD
MOTOROLA
MC68322 USER’S MANUAL
13-13
BLT2BB_SHD
Source/Halftone/Destination bitBLT to Banded Bitmap
Note: * Denotes A Parameter That The MC68322 Updates When The Frame Crosses A Band Boundary.
The BLT2BB_SHD graphic order causes the MC68322 to bitBLT a source frame to a
destination banded bitmap and apply a halftone bitmap in the process. The source, halftone,
and destination pixels are combined, as specified by the current BOOL_SHD Boolean code.
The destination bitmap parameters must have been previously defined by the SET_BBMAP
graphic order.
The source frame warp is assumed to be the FW specified in the BLT2BB_SHD graphic
order, unless a non-zero source bitmap warp was previously defined by the SET_SBMAP
graphic order, in which case the latter is used. The halftone bitmap dimensions must have
been previously defined by the SET_HTBMAP graphic order. During the processing of
halftones, wrapping occurs at the edges of the bitmap and this results in horizontal and
vertical replication (tiling) of the bitmap to cover the entire bitBLT frame area.
Halftone tiled patterns are typically anchored to the page. Thus, a bitBLT may need to take
on the halftone pattern starting at various points in the halftone bitmap depending on where
it is being positioned on the page. The halftone parameters HXR, HYR, and HA define the
precise halftone pixel that corresponds to the upper left (or lower left, when the B2T flag is
set) corners of the source and destination frames. HXR specifies the number of pixels
remaining to the right edge of the bitmap and HYR defines the number of scanlines
remaining to the bottom edge (or top edge, when the B2T flag is set). HXR and HYR must
be in the following ranges—1
≤ HXR ≤ HW and 1 ≤ HYR ≤ HH, where HW and HH are the
width and height of the halftone bitmap, respectively.
For example, when the B2T flag is clear, if the starting pixel in the halftone bitmap is
determined to be at the upper left, HXR must be set to HW, and HYR to HH. If, instead, a
180
° page is being rendered and the B2T flag is set, HXR must still be set to HW, but HYR
must be set to one.
PARAMETERS
SIZE
DESCRIPTION
0x33
BAND*
DA*
FW
FH*
SA*
HXR
HYR*
HA*
Byte
Long Word
Word
Long Word
Word
Long Word
BLT2BB_SHD Opcode.
Band number when graphic order is executed.
Destination logical bit address.
Frame width in bits.
Frame height in scanlines.
Source physical bit address.
Halftone X remainder.
Halftone Y remainder.
Halftone physical bit address of the starting pixel.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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