static void
genlin(short *x, short *y, PLINT npts)
{
/* Check for solid line */
if (plsc->nms == 0) {
if (npts== 2)
plP_line(x, y);
else
plP_polyline(x, y, npts);
}
/* Right now dashed lines don't use polyline capability -- this
should be improved */
else {
PLINT i;
/* Call escape sequence to draw dashed lines, only for drivers
that have this capability */
if (plsc->dev_dash) {
plsc->dev_npts = npts;
plsc->dev_x = x;
plsc->dev_y = y;
plP_esc(PLESC_DASH, NULL);
return;
}
for (i = 0; i < npts - 1; i++) {
grdashline(x+i, y+i);
}
}
}
static void
rdbuf_line(PLStream *pls)
{
short xpl[2], ypl[2];
PLINT npts = 2;
dbug_enter("rdbuf_line");
fread(xpl, sizeof(short), npts, pls->plbufFile);
fread(ypl, sizeof(short), npts, pls->plbufFile);
plP_line(xpl, ypl);
}
static void
grdashline(short *x, short *y)
{
PLINT nx, ny, nxp, nyp, incr, temp;
PLINT modulo, dx, dy, i, xtmp, ytmp;
PLINT tstep, pix_distance, j;
int loop_x;
short xl[2], yl[2];
double nxstep, nystep;
/* Check if pattern needs to be restarted */
if (x[0] != lastx || y[0] != lasty) {
plsc->curel = 0;
plsc->pendn = 1;
plsc->timecnt = 0;
plsc->alarm = plsc->mark[0];
}
lastx = xtmp = x[0];
lasty = ytmp = y[0];
if (x[0] == x[1] && y[0] == y[1])
return;
nx = x[1] - x[0];
dx = (nx > 0) ? 1 : -1;
nxp = ABS(nx);
ny = y[1] - y[0];
dy = (ny > 0) ? 1 : -1;
nyp = ABS(ny);
if (nyp > nxp) {
modulo = nyp;
incr = nxp;
loop_x = 0;
}
else {
modulo = nxp;
incr = nyp;
loop_x = 1;
}
temp = modulo / 2;
/* Compute the timer step */
nxstep = nxp * plsc->umx;
nystep = nyp * plsc->umy;
tstep = sqrt( nxstep * nxstep + nystep * nystep ) / modulo;
if (tstep < 1) tstep = 1;
/* tstep is distance per pixel moved */
i = 0;
while (i < modulo) {
pix_distance = (plsc->alarm - plsc->timecnt + tstep - 1) / tstep;
i += pix_distance;
if (i > modulo)
pix_distance -= (i - modulo);
plsc->timecnt += pix_distance * tstep;
temp += pix_distance * incr;
j = temp / modulo;
temp = temp % modulo;
if (loop_x) {
xtmp += pix_distance * dx;
ytmp += j * dy;
}
else {
xtmp += j * dx;
ytmp += pix_distance * dy;
}
if (plsc->pendn != 0) {
xl[0] = lastx;
yl[0] = lasty;
xl[1] = xtmp;
yl[1] = ytmp;
plP_line(xl, yl);
}
/* Update line style variables when alarm goes off */
while (plsc->timecnt >= plsc->alarm) {
if (plsc->pendn != 0) {
plsc->pendn = 0;
plsc->timecnt -= plsc->alarm;
plsc->alarm = plsc->space[plsc->curel];
}
else {
plsc->pendn = 1;
plsc->timecnt -= plsc->alarm;
plsc->curel++;
if (plsc->curel >= plsc->nms)
plsc->curel = 0;
plsc->alarm = plsc->mark[plsc->curel];
}
}
lastx = xtmp;
lasty = ytmp;
}
}