AREA allows you to specify the color used to fill areas. See COLOR for an explanation of how to specify colors with COLOR, INTENSITY and PEN. The effect of different pen numbers is given in the Drawing Mode Table, below.
If you specify a color with COLOR or INTENSITY which cannot be produced on the computer system you are using, the color may be approximated by using an available color which is close to the color specified. On some displays this may include dithering available colors to produce a color closer to the one you specified. If dithering is used, the statement will execute slower than an AREA PEN statement.
The default area fill color is PEN one. The color defined by AREA remains the area fill color until an AREA, GINIT or SCRATCH A is executed. IPLOT, PLOT, RPLOT or SYMBOL can also be used to change the area fill color.
Drawing Mode Table
The writing mode of the pen is specified by the current drawing mode and the sign of the pen number. GESCAPECRT,4 is used to change to normal drawing mode. GESCAPECRT,5 is used to change to alternate drawing mode. The following table defines the different writing modes available. P is a positive pen number, X is the present value of a pixel.
GESCAPE CRT,4 GESCAPE CRT,5
Statement Normal Alternate
AREA PEN P P BINIOR(X,P)
AREA PEN 0 0 0
AREA PEN -P BINAND(X,BINCMP(P)) BINAND(X,BINCMP(P))
