static int ffnd (ptr_level_f func, int i1, int i2, int i3, int i4, int jj1, int jj2, int jj3, int jj4, int ent, int qq, double Cont, int *zds)
{
double phi1 = 0., phi2 = 0., phi3 = 0., phi4 = 0., xav = 0., yav = 0., phiav = 0.;
int revflag = 0, i = 0;
phi1 = phi_cont(i1, jj1) - Cont;
phi2 = phi_cont(i2, jj2) - Cont;
phi3 = phi_cont(i3, jj3) - Cont;
phi4 = phi_cont(i4, jj4) - Cont;
revflag = 0;
*zds = 0;
/* le point au centre du rectangle */
xav = ( x_cont(i1) + x_cont(i3)) / 2.0 ;
yav = ( y_cont(jj1) + y_cont(jj3)) / 2.0 ;
phiav = ( phi1 + phi2 + phi3 + phi4) / 4.0;
if (ISNAN(phiav) == 1)
{
return -1;
}
if ( not_same_sign( phiav, phi4))
{
int l1, k1;
double phi;
revflag = 1 ;
l1 = i4;
k1 = jj4;
i4 = i1;
jj4 = jj1;
i1 = l1;
jj1 = k1;
l1 = i3;
k1 = jj3;
i3 = i2;
jj3 = jj2;
i2 = l1;
jj2 = k1;
phi = phi1;
phi1 = phi4;
phi4 = phi;
phi = phi3;
phi3 = phi2;
phi2 = phi;
}
/* on stocke un nouveau point */
(*func)(1, Cont, f_intercept(0.0, phi1, x_cont(i1), phiav, xav),
f_intercept(0.0, phi1, y_cont(jj1), phiav, yav));
/*
* on parcourt les segments du rectangle pour voir sur quelle face
* on sort
*/
for ( i = 0 ; ; i++)
{
int l1, k1;
double phi;
if ( not_same_sign ( phi1, phi2)) /** sortir du for **/
{
break ;
}
if ( phiav != 0.0 )
{
(*func)(1, Cont, f_intercept(0.0, phi2, x_cont(i2), phiav, xav),
f_intercept(0.0, phi2, y_cont(jj2), phiav, yav));
}
/** on permutte les points du rectangle **/
l1 = i1;
k1 = jj1;
i1 = i2;
jj1 = jj2;
i2 = i3;
jj2 = jj3;
i3 = i4;
jj3 = jj4;
i4 = l1;
jj4 = k1;
phi = phi1;
phi1 = phi2;
phi2 = phi3;
phi3 = phi4;
phi4 = phi;
}
(*func)(1, Cont, f_intercept(0.0, phi1, x_cont(i1), phi2, x_cont(i2)),
f_intercept(0.0, phi1, y_cont(jj1), phi2, y_cont(jj2)));
if ( qq == 1 && bdyp(i1, jj1) && bdyp(i2, jj2))
{
*zds = 1 ;
}
if ( revflag == 1 && ! oddp (i) )
{
i = i + 2;
}
return ( 1 + ( ( i + ent + 2) % 4));
}
static void
markp(int not)
{
oddp(not);
}
static void look(ptr_level_f func, int i, int j, int ib, int jb, int qq, double Cont, int style)
{
int ip = 0, jp = 0, im = 0, jm = 0, zds = 0, ent = 0, flag = 0, wflag = 0;
jp = j + 1;
ip = i + 1;
jm = j - 1;
im = i - 1;
/* on regarde comment est le segment de depart */
if ( jb == jm)
{
flag = 1;
}
else
{
if ( ib == im )
{
flag = 2 ;
}
else
{
if ( jb == jp )
{
flag = 3 ;
}
else if ( ib == ip )
{
flag = 4;
}
}
}
switch ( flag)
{
case 1 :
if (get_itg_cont(i, jm) > 1)
{
return;
}
ent = 1 ; /* le segment est vertical vers le bas */
/* Storing intersection point */
(*func)(0, Cont, x_cont(i),
f_intercept(Cont, phi_cont(i, jm),
y_cont(jm), phi_cont(i, j), y_cont(j)));
break;
case 2 :
if (get_itg_cont(im, j) == 1 || get_itg_cont(im, j) == 3 )
{
return;
}
ent = 2 ; /* le segment est horizontal gauche */
/* Storing intersection point */
(*func)( 0, Cont,
f_intercept(Cont, phi_cont(im, j),
x_cont(im), phi_cont(i, j), x_cont(i)), y_cont(j));
break ;
case 3 :
if (get_itg_cont(i, j) > 1 )
{
return;
}
ent = 3 ; /* le segment est vertical haut */
/* Storing intersection point */
(*func)(0, Cont, x_cont(i), f_intercept(Cont, phi_cont(i, j),
y_cont(j), phi_cont(i, jp), y_cont(jp)));
break ;
case 4 :
if (get_itg_cont(i, j) == 1 || get_itg_cont(i, j) == 3 )
{
return;
}
ent = 4 ; /* le segment est horizontal droit */
/* Storing intersection point */
(*func)(0, Cont, f_intercept(Cont, phi_cont(i, j),
x_cont(i), phi_cont(ip, j), x_cont(ip)),
y_cont(j));
break;
default :
break;
}
wflag = 1;
while ( wflag)
{
jp = j + 1;
ip = i + 1;
jm = j - 1;
im = i - 1;
switch ( ent)
{
case 1 :
inc_itg_cont(i, jm, 2L);
ent = ffnd(func, i, ip, ip, i, j, j, jm, jm, ent, qq, Cont, &zds);
/* on calcule le nouveau point, ent donne la
direction du segment a explorer */
switch ( ent)
{
case -1:
wflag = 0;
break;
case 1 :
i = ip ;
break ;
case 2 :
i = ip;
j = jm;
break ;
}
break ;
case 2 :
inc_itg_cont(im, j, 1L);
ent = ffnd(func, i, i, im, im, j, jm, jm, j, ent, qq, Cont, &zds);
switch ( ent)
{
case -1:
wflag = 0;
break;
case 2 :
j = jm ;
break ;
case 3 :
i = im;
j = jm;
break ;
}
break ;
case 3 :
inc_itg_cont(i, j, 2L);
ent = ffnd(func, i, im, im, i, j, j, jp, jp, ent, qq, Cont, &zds);
switch ( ent)
{
case -1:
wflag = 0;
break;
case 3 :
i = im;
break ;
case 4 :
i = im;
j = jp;
break ;
}
break ;
case 4 :
inc_itg_cont(i, j, 1L);
ent = ffnd(func, i, i, ip, ip, j, jp, jp, j, ent, qq, Cont, &zds);
switch ( ent)
{
case -1:
wflag = 0;
break;
case 4 :
j = jp;
break ;
case 1 :
i = ip;
j = jp;
break ;
}
break ;
}
/** new segment is on the boundary **/
if ( zds == 1)
{
switch ( ent)
{
case 1 :
inc_itg_cont(i, (j - 1), 2L);
break ;
case 2 :
inc_itg_cont(i - 1, j, 1L);
break ;
case 3 :
inc_itg_cont(i, j, 2L);
break ;
case 4 :
inc_itg_cont(i, j, 1L);
break ;
}
/** we must quit the while loop **/
wflag = 0 ;
}
/** init point was inside the domain */
if ( qq == 2)
{
switch ( ent)
{
case 1 :
if ( get_itg_cont (i, j - 1) > 1)
{
wflag = 0 ;
}
break ;
case 2 :
if ( oddp(get_itg_cont(i - 1, j)))
{
wflag = 0 ;
}
break ;
case 3 :
if ( get_itg_cont(i, j) > 1)
{
wflag = 0 ;
}
break ;
case 4 :
if ( oddp(get_itg_cont(i, j)))
{
wflag = 0 ;
}
break ;
}
}
}
if ( func == GContStore2 )
{
GContStore2Last();
}
else
{
/* contour2di only computes level curves, not display them. */
sciprint(_("%s is only made to compute level curves and not display them.\n"), "Contourdi");
}
}
