for (i1=0,is=i1+i2*n1; i1<n1m1 && ni>0; ++i1,is+=1) {
if (sset(i1,i2,flags)) {
float d = delta(fc,f[i2][i1],f[i2][i1+1]);
FloatList x1 = new FloatList();
FloatList x2 = new FloatList();
for (i2=0,is=i1+i2*n1; i2<n2m1 && ni>0; ++i2,is+=n1) {
if (wset(i1,i2,flags)) {
float d = delta(fc,f[i2][i1],f[i2+1][i1]);
FloatList x1 = new FloatList();
FloatList x2 = new FloatList();
for (i1=0,is=i1+i2*n1; i1<n1m1 && ni>0; ++i1,is+=1) {
if (sset(i1,i2,flags)) {
float d = delta(fc,f[i2][i1],f[i2][i1+1]);
FloatList x1 = new FloatList();
FloatList x2 = new FloatList();
for (i2=0,is=i1+i2*n1; i2<n2m1 && ni>0; ++i2,is+=n1) {
if (wset(i1,i2,flags)) {
float d = delta(fc,f[i2][i1],f[i2+1][i1]);
FloatList x1 = new FloatList();
FloatList x2 = new FloatList();
for (i1=0,is=i1+i2*n1; i1<n1m1 && ni>0; ++i1,++is) {
if (sset(i1,i2,flags)) {
float d = delta(fc,f[i2][i1],f[i2][i1+1]);
FloatList x1 = new FloatList();
FloatList x2 = new FloatList();