void wordtostate(Word_t s, int bump, bstate state)
{
char stack[MAXSTATEWIDTH];
int sp,i,type,leftcolor;
cell *sti;
leftcolor = SENTI(s); // sentinel
sti = &state[0];
for (i = sp = 0; i < statewidth; sti++, i++) {
sti->type = type = (s >> (3*i)) & 7;
sti->left = sti->right = i;
if (ISNEEDY(type)) {
sti->needycolor = leftcolor ^ COLOR; // assume opposite color
if (type & HASL) {
if (!sp) {
printf("sp=0! i=%d s=%3lo bump=%d\n",i, s, bump);
exit(0);
}
sti->right = state[sti->left = stack[--sp]].right;
state[sti->left].right = state[sti->right].left = i;
sti->needycolor ^= (sti->left == i-1); // check color assumption
}
if (type & HASR)
stack[sp++] = i;
if (i == bump)
sti->needycolor = BLACK; // color normalization
leftcolor = sti->needycolor;
} else leftcolor = type & 1;
}
if (sp) {
printf("sp=%d s=%3lo bump=%d\n",sp, s, bump);
exit(0);
}
}
int wordtostate(uint64_t s, int bump, bstate state)
{
int stack[MAXSTATEWIDTH]; // holds pairs of (groupleftend,grouprightend)
int sp,i,type,leftcolor; // at most statewidth ends on stack
cell *sti;
leftcolor = SENTI(s); // sentinel
for (sti = &state[i = sp = 0]; i < statewidth; sti++, i++) {
sti->type = type = s & 7;
s >>= 3;
if (ISNEEDY(type)) {
sti->color = leftcolor ^ COLOR; // assume opposite color
if ((type & HASL) && i) {
state[sti->left = stack[--sp]].right = i; // extend group
if (sti->left == i-1) // assumption was wrong
sti->color = leftcolor;
} else stack[sp++] = i; // new left end
if (type & HASR)
stack[sp++] = i; // new right end
else state[sti->right = stack[--sp]].left = i; // connect ends
if (i == bump)
sti->color = WHITE; // color normalization
leftcolor = sti->color;
} else leftcolor = type & COLOR;
}
return sp==0;
}
