0000122332210000
0001223333221000
0012223333222100
0001223333221000
0000122332210000
The
next step is to convert the numbers
0-3
into binary numbers, which will be used to
build the color descriptor words of the sprite
data
structure.
The
section below shows
how to do this.
BUILDING
THE
DATA
STRUCTURE
After defining the sprite, you need to build its
data
structure, which is a series of 16-bit
words in a contiguous memory area. Some of the words contain position and control
information and some contain color descriptions.
To
create a sprite's
data
structure, you
need to:
o Write the horizontal and vertical position of the sprite into the first control
word.
o Write the vertical stopping position into the second control word.
o Translate the decimal color numbers 0 - 3
in
your sprite grid picture into
binary color numbers.
Use
the binary values to build color descriptor (data)
words and write these words into the
data
structure.
o Write the control words
that
indicate the end of the sprite
data
structure.
Table
4-1
shows a sprite
data
structure with the memory location and function of each
word:
Sprite Hardware
99
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