void
picurve(register int *x,
register int *y,
int npts)
{
register int nseg; /* effective resolution for each curve */
register int xp; /* current point (and temporary) */
register int yp;
int pxp, pyp; /* previous point (to make lines from) */
int i; /* inner curve segment traverser */
int length = 0;
double w; /* position factor */
double t1, t2, t3; /* calculation temps */
if (x[1] == x[npts] && y[1] == y[npts]) {
x[0] = x[npts - 1]; /* if the lines' ends meet, make */
y[0] = y[npts - 1]; /* sure the curve meets */
x[npts + 1] = x[2];
y[npts + 1] = y[2];
} else { /* otherwise, make the ends of the */
x[0] = x[1]; /* curve touch the ending points of */
y[0] = y[1]; /* the line segments */
x[npts + 1] = x[npts];
y[npts + 1] = y[npts];
}
pxp = (x[0] + x[1]) / 2; /* make the last point pointers */
pyp = (y[0] + y[1]) / 2; /* point to the start of the 1st line */
tmove2(pxp, pyp);
for (; npts--; x++, y++) { /* traverse the line segments */
xp = x[0] - x[1];
yp = y[0] - y[1];
nseg = (int) groff_hypot((double) xp, (double) yp);
xp = x[1] - x[2];
yp = y[1] - y[2];
/* `nseg' is the number of line */
/* segments that will be drawn for */
/* each curve segment. */
nseg = (int) ((double) (nseg + (int) groff_hypot((double) xp, (double) yp)) /
res * PointsPerInterval);
for (i = 1; i < nseg; i++) {
w = (double) i / (double) nseg;
t1 = w * w;
t3 = t1 + 1.0 - (w + w);
t2 = 2.0 - (t3 + t1);
xp = (((int) (t1 * x[2] + t2 * x[1] + t3 * x[0])) + 1) / 2;
yp = (((int) (t1 * y[2] + t2 * y[1] + t3 * y[0])) + 1) / 2;
HGtline(xp, yp);
if (length++ > LINELENGTH) {
length = 0;
printf("\\\n");
}
}
}
}
void
Paramaterize(int x[],
int y[],
double h[],
int n)
{
register int dx;
register int dy;
register int i;
register int j;
double u[MAXPOINTS];
for (i = 1; i <= n; ++i) {
u[i] = 0;
for (j = 1; j < i; j++) {
dx = x[j + 1] - x[j];
dy = y[j + 1] - y[j];
/* Here was overflowing, so I changed it. */
/* u[i] += sqrt ((double) (dx * dx + dy * dy)); */
u[i] += groff_hypot((double) dx, (double) dy);
}
}
for (i = 1; i < n; ++i)
h[i] = u[i + 1] - u[i];
} /* end Paramaterize */
void
HGArc(register int cx,
register int cy,
int px,
int py,
int angle)
{
double xs, ys, resolution, fullcircle;
int m;
register int mask;
register int extent;
register int nx;
register int ny;
register int length;
register double epsilon;
xs = px - cx;
ys = py - cy;
length = 0;
resolution = (1.0 + groff_hypot(xs, ys) / res) * PointsPerInterval;
/* mask = (1 << (int) log10(resolution + 1.0)) - 1; */
(void) frexp(resolution, &m); /* A bit more elegant than log10 */
for (mask = 1; mask < m; mask = mask << 1);
mask -= 1;
epsilon = 1.0 / resolution;
fullcircle = (2.0 * pi) * resolution;
if (angle == 0)
extent = (int) fullcircle;
else
extent = (int) (angle * fullcircle / 360.0);
HGtline(px, py);
while (--extent >= 0) {
xs += epsilon * ys;
nx = cx + (int) (xs + 0.5);
ys -= epsilon * xs;
ny = cy + (int) (ys + 0.5);
if (!(extent & mask)) {
HGtline(nx, ny); /* put out a point on circle */
if (length++ > LINELENGTH) {
length = 0;
printf("\\\n");
}
}
} /* end for */
} /* end HGArc */
double hypot(const position &a)
{
return groff_hypot(a.x, a.y);
}
