circf(3G)

NAME
     circf, circfi, circfs - draws a filled circle

FORTRAN 77 SPECIFICATION
     subroutine circf(x, y, radius)
     real x, y, radius

     subroutine circfi(x, y, radius)
     integer*4 x, y, radius

     subroutine circfs(x, y, radius)
     integer*2 x, y, radius

     The routines above are functionally the same even though the type
     declarations for the coordinates differ.

PARAMETERS
     x        expects the x coordinate of the center of the filled circle
              specified in world coordinates.

     y        expects the y coordinate of the center of the filled circle
              specified in world coordinates.

     radius   expects the length of the radius of the filled circle.

DESCRIPTION
     circf draws a filled circle in the x-y plane (z = 0).  To draw a circle
     in a plane other than the x-y plane, define the circle in the x-y plane
     and then rotate or translate the circle. Note that filled circles rotated
     outside the 2-D x-y plane appear as filled ellipses.

     A circle is drawn as a single polygon, and therefore inherits all
     properties that affect the drawing of polygons.  These include the
     current color, writemask, fill pattern, shade model, polygon antialiasing
     mode, polygon scan conversion mode, and subpixel mode.  Front-face and
     back-face elimination work correctly with filled circles, which are
     front-facing when viewed from the positive z half-space.  Some polygon
     modes are applicable only if old-style scan conversion is defeated.  (See
     note below.)

     After circf executes, the graphics position is undefined.

SEE ALSO
     arcf, backfa, bgnpol, circ, frontf, glcomp, polymo, polysm, scrsub,
     setpat, shadem, subpix

NOTES
     By default circf draws a polygon using the old-style scan conversion
     algorithm, rather than the point sampling algorithm used by bgnpol and
     endpol.  Point sampling is preferred over old-style scan conversion
     because it has higher performance, it results in higher-quality images
     when blending, logical operations, or stenciling are used, and it
     supports new rendering features such as texture mapping, fog, and
     antialiasing.  Call glcomp(GLCOLD,0) to enable point sampling of polygons
     generated by circf.

     The identifier of the function circf declared in gl/gl.h conflicts with
     the identifier of the external variable circf declared in regexp.h.  If
     you need to include gl/gl.h and regexp.h in the same source file, embed
     the "#include <regexp.h>" statement, and all references to the variable
     circf in the source file, with a "#define circf re_circf" and "#undef
     re_circf" pair of statements.