(128,65)
IWkI
(128,65) (144,65)
Sprite 0 Sprite 1
Figure
4-12:
Placing Sprites Next to Each Other
Attached
Sprites
You can create sprites
that
have fifteen possible color choices (plus transparent) instead
of three (plus transparent), by "attaching" two sprites.
To
create attached sprites, you
must:
o
Use
two channels per sprite, creating two sprites of the same size and located
at
the same position.
o Set a bit called ATTACH in the second sprite control word.
The
fifteen colors are selected from the full range of color registers available to sprites -
registers
17
through 31. The extra color choices are possible because each pixel contains
four bits instead of only two as
in
the normal, unattached sprite. Each sprite
in
the
attached pair contributes two bits to the binary color selector number. For example, if
you are using sprite
DMA
channels 0 and
1,
the high- and low-order color descriptor
words for line 1 in both
data
structures are combined into line 1 of the attached object.
Sprites can be attached
in
the following combinations:
116
Sprite Hardware
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