Tandy 1000 Basic Reference Manual page 201

Chapter 10 I
BASIC
Ke.ywords
LINE/Graphics Statement
Draws a line or a box on the video display.
The STEP option tells BASIC that the (x,y) coordinates are rela-
tive t o the last point referenced. If you use STEP with the sec-
ond set of coordinates, the coordinates are relative to the first
set of coordinates.
(x1,yl) specifies the point a t which t o begin the line. x l is the
horizontal coordinate, and y l is the vertical coordinate. If you
omit (x1,yl) BASIC begins the line a t the last point referenced
on the screen.
(x2,yZ) specifies the point at which to end the line.
x2
is the hor-
izontal coordinate and y 2 is the vertical coordinate.
Color indicates the color of the line.
See Chapter 8, "Displaying Color and Graphics" for information
on coordinates and colors for the current screen mode.
If
you specify coordinates that are not in the range of the cur-
rent viewport, BASIC displays only that portion of the line that
is within the viewport.
With the
B
option, BASIC draws a box. The points that you
specify are opposite corners.
If
you specify both the
B and F options, BASIC draws a box and
fills the box in with color.
Style lets you select the line-style used when drawing normal
lines and unfilled boxes. Style is a 16-bit integer. Each bit repre-
sents a point in the line.
If
the bit equals
1,
then the point
is
drawn.
If the bit equals zero, then the point is not drawn. A zero
bit does not erase a previously drawn point; therefore, you may
want to draw a background line first to have a known back-
ground. The style pattern is repeated as necessary, to complete
the line drawing.
199