Commodore Plus 4 - GRAPHIC KEYS; ESCAPE

BASIC Version 3.5 Commands, Functions, and System Variables 23
2. The first coordinates name the center of the shape. The default center is the
current location of the pixel cursor.
3. Horizontal radius is the distance from the center of the shape to the left and
right sides of the shape.
4. Vertical radius is the distance from the center of the shape to the top and
bottom of the shape. Because vertical dots on the high-resolution graphic screen
are slightly farther apart than horizontal dots are, when the vertical and horizon
tal radii have the same value, the shape drawn is an oval, not a circle. To draw a
circle, the vertical radius must be scaled to the horizontal radius (e.g., 50 horizon
tal, 47 vertical). For multicolor coordinates, 25 horizontal is about 47 vertical.
5. Use the starting angle only when you want to draw an arc. Zero degrees is at
the top of the screen; 180 is at the bottom; 90 is to the right; and 270 is to the left.
6. The ending angle for an arc defaults to 360 if not specified.
7. You can draw a shape tilted at an angle from 0 to 360 degrees. The default is
0, which is no tilt.
8. You choose the shape of the CIRCLE drawing by choosing the number of
degrees between the segments in the drawing. The default number of degrees
between shape segments is 2 degrees, which draws a circle.
When you draw a circle on the screen, you are actually drawing a 180-sided
polygon (360 divided by 2, the default segment value). The larger the increment of
degrees between segments, the more angular the drawing. For example, a seg
ment value of 120 draws a triangle, not a circle.
To draw a polygon with the CIRCLE command, divide 360 (the total number
of degrees in a real circle) by the number of sides you want the shape to have. For
example, to draw a hexagon, divide 360 by 6. Then use the result, 60, as the
segment parameter.
Note: Although the segment-size parameter can have a value of up to 255, any
value between 180 and 255 draws a straight line.
Examples: 10 GRAPHIC 2,1
20 CIRCLE, 140,80, 90,50,180,320 Draws an arc.
30 CIRCLE, 160,100, 60,50,,,,90 Draws a diamond.
40 CIRCLE, 160,100, 60,50,,,90,120 Draws a triangle rotated
90 degrees.
50 CIRCLE, 160,75, 72,60 Draws a circle.
CLOSE Abbr. clO
CLOSE file number
Closes access to a peripheral device or a data file on tape or disk. CLOSE is
paired with the OPEN command, which gives access to a data file or peripheral
device. You must CLOSE the file or device with the same logical file number you
used to OPEN it.
Be sure to CLOSE files and devices when you finish accessing them; leaving