Chapter
10
I
BASIC Keywords
This means that instead of stopping when
1
line
of
points has
been painted without changing the color, PAINT can continue, if
you specify
background.
For example, normally you cannot draw
alternating blue and red lines on
a
red background because
PAINT stops after painting the
first
red line. However, by speci-
fying red
as
the background color (&HAA), you can draw the red
line over the red background.
PAINT must start on a nonborder point. If the point
is
already
border
or
color
color, BASIC does not execute the PAINT
statement.
PAINT can fill any figure, but painting jagged edges
or
very
complex figures may result in an “Out
of
memory” error. If this
happens, you must use the CLEAR statement
to
increase the
amount of stack space available.
Tiling
Tiling lets you select a pattern
to
be used when painting an area
on the screen. The tile mask is 8-bits wide and may be a maxi-
mum of
64
bytes long:
X,Y
8
7
6
5
4 3
2
1
tile byte
0,0
0,1
012
073
........
1
........
2
........
3
........
4
0,63
........
64
Each byte in the mask represents
8
points along the horizontal
row and
1
point along the vertical row. PAINT repeats the tile
mask pattern (horizontally and vertically)
to
create a uniform
pattern over the entire area being painted.
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