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/* This file contains the circle method, which is a standard part of
libplot. It draws an object: a circle with center x,y and radius r. */
#include "sys-defines.h"
#include "plot.h"
#include "extern.h"
int
#ifdef _HAVE_PROTOS
_h_fcircle (double x, double y, double r)
#else
_h_fcircle (x, y, r)
double x, y, r;
#endif
{
double radius;
/* if affine map from user frame to device frame is anisotropic, use
generic class method to draw an inscribed polyline */
if (!_plotter->drawstate->transform.uniform)
return _g_fcircle (x, y, r);
if (!_plotter->open)
{
_plotter->error ("fcircle: invalid operation");
return -1;
}
/* otherwise use HP-GL's native circle-drawing facility, as follows */
_plotter->endpath (); /* flush polyline if any */
(_plotter->drawstate->pos).x = x; /* move to center (a libplot convention) */
(_plotter->drawstate->pos).y = y;
radius = sqrt(XDV(r,0)*XDV(r,0)+YDV(r,0)*YDV(r,0));
/* sync pen position and line attributes, incl. pen width */
_plotter->set_position();
_plotter->set_attributes();
if (_plotter->hpgl_version >= 1)
/* have a polygon buffer, and will use it */
{
/* enter polygon mode, draw circle, exit polygon mode */
if (_plotter->hpgl_version == 1)
sprintf (_plotter->outbuf.current, "PM0;CI%d;PM2;", IROUND(radius));
else /* HP-GL/2, use small chord angle */
sprintf (_plotter->outbuf.current, "PM0;CI%d,2;PM2;", IROUND(radius));
_update_buffer (&_plotter->outbuf);
/* lift pen */
strcpy (_plotter->outbuf.current, "PU;");
_update_buffer (&_plotter->outbuf);
_plotter->pendown = false;
if (_plotter->drawstate->fill_level)
{
/* select appropriate pen and fill the circle */
_plotter->set_fill_color ();
strcpy (_plotter->outbuf.current, "FP;");
_update_buffer (&_plotter->outbuf);
}
/* select appropriate pen and edge the circle */
_plotter->set_pen_color ();
strcpy (_plotter->outbuf.current, "EP;");
_update_buffer (&_plotter->outbuf);
}
else
/* don't have a polygon buffer, won't do filling */
{
/* select appropriate pen */
_plotter->set_pen_color ();
/* draw circle */
sprintf (_plotter->outbuf.current, "CI%d;", IROUND(radius));
_update_buffer (&_plotter->outbuf);
}
return 0;
}
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