Commodore 128D - Page 125

Sprites use an entirely different coordinate plane than bit-map coor
dinates. The bit-map coordinates range from points 0,0 (the top left
corner) to 319,199 (bottom right corner). The visible sprite coordi
nates start at point 24,50 and end at point 344,250. The rest of the
sprite coordinates are off the screen and are not visible, but the
sprite still moves according to them. The off-screen locations allow
sprites to move smoothly onto and off of the screen. Figure 6-7 illus
trates the sprite coordinate plane and the visible sprite positions.
0 (MO) 24 ($18)
344 <I1M)
208 (tOO)-,
250 (SFA>-
VISIBLE VIEWING AREA
NTSC
40 COLUMNS
25 ROWS
8 (tot)
-50 (132)
— 229 (MS)
— - 250 (SFA)
I
488 (S1EB) 24 ($18)
I
I I
I I
I I
I ($140) 344 (fiM)
Figure 6-7. Visible Sprite Coordinates
Now RUN the entire program with all the steps included. You have
just written your first sprite program. You have created a raceway
with two racing cars. Try adding more cars and more objects on the
screen. Experiment by drawing other sprites and include them in the
raceway. You are now well on the way in sprite programming. Use
your imagination and think of other scenes and objects you can
animate. Soon you will be able to create all kinds of animated com
puter "movies."
To stop the sprites, press RUN/STOP and RESTORE at the same
time.
117
USING C128 MODE—Color, Animation and Sprite Graphics Statements