Commodore Plus 4 - Page 30

18 The BASIC Language
draw with more than one color on the same screen. Sources 0 and 3 are global
colors, which means that changing the colors for these sources affects all shapes
previously drawn with them.
If you want to use the default value (1, the current foreground color), you do
not have to type a number, but you must type a comma before the next parameter.
2. The first set of coordinates names the location of one corner of the box. The
second set names the location of the opposite corner of the box. The second set of
coordinates can be omitted. They will default to the pixel cursor. If you omit the
coordinates, type one comma instead. These are the only coordinates you give.
You can name either of the opposite sets of corners, and you can enter them in
any order (i.e., you do not have to enter the top corner first). If you name corners
with the same row or column coordinate, you will draw a line instead of a
rectangle.
3. After the box is drawn, the pixel cursor is at the location of the second set of
coordinates.
4. You can draw the box tilted at any angle from 0 to 360. For example, a
45-degree angle draws a diamond shape. The default value is 0, no tilting. The
tilting is done after the box is calculated. Therefore, the corners will not be at the
specified coordinates. If you omit this parameter and use the Fill parameter, you
must type a comma in place of the angle parameter.
5. You can draw the box as an outline or as a solid block. The default is 0,
which draws an outline. If you want to draw a solid block, select 1 as the value for
this parameter. No other values are legal. Since this is the last parameter, you do
not need to type a comma to take its place if you do not use this parameter.
Examples: BOX, 60,50, 840,150 Draws a rectangle in outline.
BOX, 80,50, 150,130,45,1 Draws a solid rectangle tilted at 45
degrees.
10 GRAPHIC 2,1 Enters split-screen high-resolution mode.
20 COLOR 1,5,4 Changes the color of source 1, thereby
indirectly changing the color used to
draw the boxes.
30 FOR A=0 TO 360 STEP 10 Sets up a loop to increment the value of
the angle parameter in the BOX
command.
40 BOX, 120,50, 200,100, A Draws a rectangle at the angle of A.
50 NEXT
CHAR Abbr. chA
CHAR color source, column coordinate, row coordinate, string, reverse mode
Displays a message at a specified screen location in any text or graphic mode.
You give the column and row coordinates of the message in the CHAR com
mand. You can also print the message in reversed-image mode.