SUBROUTINE CSHADE

The  CSHADE subroutine fills in an  area defined by a segment of a  circl using equally spaced lines at a given angle with a specified line type. A full circle may be used.

CALL CSHADE (x,y,r,a1,a2,s,l,d,t,w,m1,m2)

x,y   (R): location of circle center
r     (R): segment or circle radius
a1,a2 (R): segment start and stop angles (a2>=a1)
            if a2-a1=360 a full circle is used otherwise
            the area is a pie segment
l     (I): shade format control
           = -3 : clear area and outline
           = -2 : clear area
           = -1 : clear outline
           =  0 : no action
           =  1 : draw outline
           =  2 : shade area
           =  3 : shade area and outline
d     (R): distance between shading lines
t     (R): angle of shading lines in degrees
w     (R): working array dimensioned at least 3*n where
            n=int((a2-a1)/(180*atan(s/r)/pi)+1)
m1    (R): line type of shading
            < 0 : shading done with current line type
           => 0 : new line type (see NEWPEN)
m2    (R): line type for area outline
            < 0 : use prior line type
           => 0 : new line type (see NEWPEN)