ref: 3b7e03a30ed29ee0666c00568bf67b8179c28d12
dir: /sys/src/cmd/pic/linegen.c/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include "pic.h"
#include "y.tab.h"
obj *linegen(int type)
{
static double prevdx = HT;
static double prevdy = 0;
static double prevw = HT10;
static double prevh = HT5;
int i, j, some, head, ddtype, invis, chop, battr, with;
double ddval, chop1, chop2, x0, y0, x1, y1;
double fillval = 0;
double theta;
double defx, defy, xwith, ywith;
obj *p, *ppos;
static int xtab[] = { 1, 0, -1, 0 }; /* R=0, U=1, L=2, D=3 */
static int ytab[] = { 0, 1, 0, -1 };
double dx[500], dy[500];
int ndxy;
double nx, ny;
Attr *ap, *chop_ap[4];
nx = curx;
ny = cury;
defx = getfval("linewid");
defy = getfval("lineht");
prevh = getfval("arrowht");
prevw = getfval("arrowwid");
dx[0] = dy[0] = ndxy = some = head = invis = battr = with = 0;
chop = chop1 = chop2 = 0;
ddtype = ddval = xwith = ywith = 0;
for (i = 0; i < nattr; i++) {
ap = &attr[i];
switch (ap->a_type) {
case TEXTATTR:
savetext(ap->a_sub, ap->a_val.p);
break;
case HEAD:
head += ap->a_val.i;
break;
case INVIS:
invis = INVIS;
break;
case NOEDGE:
battr |= NOEDGEBIT;
break;
case DOT:
case DASH:
ddtype = ap->a_type==DOT ? DOTBIT : DASHBIT;
if (ap->a_sub == DEFAULT)
ddval = getfval("dashwid");
else
ddval = ap->a_val.f;
break;
case SAME:
dx[ndxy] = prevdx;
dy[ndxy] = prevdy;
some++;
break;
case LEFT:
dx[ndxy] -= (ap->a_sub==DEFAULT) ? defx : ap->a_val.f;
some++;
hvmode = L_DIR;
break;
case RIGHT:
dx[ndxy] += (ap->a_sub==DEFAULT) ? defx : ap->a_val.f;
some++;
hvmode = R_DIR;
break;
case UP:
dy[ndxy] += (ap->a_sub==DEFAULT) ? defy : ap->a_val.f;
some++;
hvmode = U_DIR;
break;
case DOWN:
dy[ndxy] -= (ap->a_sub==DEFAULT) ? defy : ap->a_val.f;
some++;
hvmode = D_DIR;
break;
case HEIGHT: /* length of arrowhead */
prevh = ap->a_val.f;
break;
case WIDTH: /* width of arrowhead */
prevw = ap->a_val.f;
break;
case TO:
if (some) {
nx += dx[ndxy];
ny += dy[ndxy];
ndxy++;
dx[ndxy] = dy[ndxy] = some = 0;
}
ppos = attr[i].a_val.o;
if (ppos == NULL)
ERROR "no tag defined for `to'" FATAL;
dx[ndxy] = ppos->o_x - nx;
dy[ndxy] = ppos->o_y - ny;
some++;
break;
case BY:
if (some) {
nx += dx[ndxy];
ny += dy[ndxy];
ndxy++;
dx[ndxy] = dy[ndxy] = some = 0;
}
ppos = ap->a_val.o;
if (ppos == NULL)
ERROR "no tag defined for `by'" FATAL;
dx[ndxy] = ppos->o_x;
dy[ndxy] = ppos->o_y;
some++;
break;
case THEN: /* turn off any previous accumulation */
if (some) {
nx += dx[ndxy];
ny += dy[ndxy];
ndxy++;
dx[ndxy] = dy[ndxy] = some = 0;
}
break;
case FROM:
case AT:
ppos = ap->a_val.o;
if (ppos == NULL)
ERROR "no tag defined for `from' or `at'" FATAL;
nx = curx = ppos->o_x;
ny = cury = ppos->o_y;
break;
case WITH:
with = ap->a_val.i;
break;
case CHOP:
if (ap->a_sub != PLACENAME) {
if( chop == 0)
chop1 = chop2 = ap->a_val.f;
else
chop2 = ap->a_val.f;
}
chop_ap[chop++] = ap;
break;
case FILL:
battr |= FILLBIT;
if (ap->a_sub == DEFAULT)
fillval = getfval("fillval");
else
fillval = ap->a_val.f;
break;
}
}
if (with) { /* this doesn't work at all */
switch (with) {
case CENTER:
xwith = (dx[1] - dx[0]) / 2; ywith = (dy[1] - dy[0]) / 2; break;
}
for (i = 0; i < ndxy; i++) {
dx[i] -= xwith;
dy[i] -= ywith;
}
curx += xwith;
cury += ywith;
}
if (some) {
nx += dx[ndxy];
ny += dy[ndxy];
ndxy++;
defx = dx[ndxy-1];
defy = dy[ndxy-1];
} else {
defx *= xtab[hvmode];
defy *= ytab[hvmode];
dx[ndxy] = defx;
dy[ndxy] = defy;
ndxy++;
nx += defx;
ny += defy;
}
prevdx = defx;
prevdy = defy;
if (chop) {
if (chop == 1 && chop1 == 0) /* just said "chop", so use default */
chop1 = chop2 = getfval("circlerad");
theta = atan2(dy[0], dx[0]);
x0 = chop1 * cos(theta);
y0 = chop1 * sin(theta);
curx += x0;
cury += y0;
dx[0] -= x0;
dy[0] -= y0;
theta = atan2(dy[ndxy-1], dx[ndxy-1]);
x1 = chop2 * cos(theta);
y1 = chop2 * sin(theta);
nx -= x1;
ny -= y1;
dx[ndxy-1] -= x1;
dy[ndxy-1] -= y1;
dprintf("chopping %g %g %g %g; cur=%g,%g end=%g,%g\n",
x0, y0, x1, y1, curx, cury, nx, ny);
}
p = makenode(type, 5 + 2 * ndxy);
curx = p->o_val[0] = nx;
cury = p->o_val[1] = ny;
if (head || type == ARROW) {
p->o_nhead = getfval("arrowhead");
p->o_val[2] = prevw;
p->o_val[3] = prevh;
if (head == 0)
head = HEAD2; /* default arrow head */
}
p->o_attr = head | invis | ddtype | battr;
p->o_fillval = fillval;
p->o_val[4] = ndxy;
nx = p->o_x;
ny = p->o_y;
for (i = 0, j = 5; i < ndxy; i++, j += 2) {
p->o_val[j] = dx[i];
p->o_val[j+1] = dy[i];
if (type == LINE || type == ARROW)
extreme(nx += dx[i], ny += dy[i]);
else if (type == SPLINE && i < ndxy-1) {
/* to compute approx extreme of spline at p,
/* compute midway between p-1 and p+1,
/* then go 3/4 from there to p */
double ex, ey, xi, yi, xi1, yi1;
xi = nx + dx[i]; yi = ny + dy[i]; /* p */
xi1 = xi + dx[i+1]; yi1 = yi + dy[i+1]; /* p+1 */
ex = (nx+xi1)/2; ey = (ny+yi1)/2; /* midway */
ex += 0.75*(xi-ex); ey += 0.75*(yi-ey);
extreme(ex, ey);
nx = xi; ny = yi;
}
}
p->o_ddval = ddval;
if (dbg) {
printf("S or L from %g %g to %g %g with %d elements:\n", p->o_x, p->o_y, curx, cury, ndxy);
for (i = 0, j = 5; i < ndxy; i++, j += 2)
printf("%g %g\n", p->o_val[j], p->o_val[j+1]);
}
extreme(p->o_x, p->o_y);
extreme(curx, cury);
return(p);
}