Apple IIe - Page 246

246
Apple
lie
Users
Handbook
n
is
the
index
of
the
shape
in
the
shape
table
.
x,y
is
the
position
from
which
to
erase
the
shape.
In
order
to
erase a
previously
displayed
shape,
the
ROTation,
SCALE, and
HCOLOR
variables must be
the
same
as
when
the
shape
was
drawn.
PROGRAMMING
WITH
SHAPE
TABLES
Shape
tables
can be used in a variety
of
implementations.
They are especially useful
for
movement
and pattern
replication.
The
following
programs
serve
as
examples
of
the
effects
of
exe-
cuting
the
four
shape
table
commands
.
PROGi
10
HGR2
20
FOR
I = 1
TO
40
30
SCALE= I
40
ROT=
I
50
HCOLOR
=1/6
60
DRAW
1AT140,96
70
NEXT
I
80
GOTO
20
10
HGR2
20
SCALE=
20
30
HCOLOR
= 3
PROG
II
40
FOR
I=
0
TO
63
50
ROT=
I
60
DRAW
1AT140,96
70
XDRAW
1AT140,96
80
NEXT
I
90
GOTO
40