/*-
* Update the status of this vertex on the forced vertex queue. If
* the vertex has become untileable set tp->done. This is supposed
* to detect dislocations -- never call this routine with a completely
* tiled vertex.
*
* Check for untileable vertices in check_vertex and stop tiling as
* soon as one finds one. I don't know if it is possible to run out
* of forced vertices while untileable vertices exist (or will
* cavities inevitably appear). If this can happen, add_random_tile
* might get called with an untileable vertex, causing ( n <= 1).
* (This is what the tp->done checks for).
*
* A delayLoop celebrates the dislocation.
*/
static void
check_vertex(ModeInfo * mi, fringe_node_c * vertex, tiling_c * tp)
{
rule_match_c hits[MAX_TILES_PER_VERTEX * N_VERTEX_RULES];
int n_hits = match_rules(vertex, hits, False);
unsigned forced_sides = 0;
if (vertex->rule_mask == 0) {
tp->done = True;
if (MI_IS_VERBOSE(mi)) {
(void) fprintf(stderr, "Dislocation occurred!\n");
}
tp->busyLoop = CELEBRATE; /* Should be able to recover */
}
if (1 == find_completions(vertex, hits, n_hits, S_LEFT, 0 /*, False */ ))
forced_sides |= S_LEFT;
if (1 == find_completions(vertex, hits, n_hits, S_RIGHT, 0 /*, False */ ))
forced_sides |= S_RIGHT;
if (forced_sides == 0) {
if (vertex->list_ptr != 0) {
forced_node_c *node = *vertex->list_ptr;
*vertex->list_ptr = node->next;
if (node->next != 0)
node->next->vertex->list_ptr = vertex->list_ptr;
free(node);
tp->forced.n_nodes--;
if (!vertex->off_screen)
tp->forced.n_visible--;
vertex->list_ptr = 0;
}
} else {
forced_node_c *node;
if (vertex->list_ptr == 0) {
if ((node = ALLOC_NODE(forced_node_c)) == NULL)
return;
node->vertex = vertex;
node->next = tp->forced.first;
if (tp->forced.first != 0)
tp->forced.first->vertex->list_ptr = &(node->next);
tp->forced.first = node;
vertex->list_ptr = &(tp->forced.first);
tp->forced.n_nodes++;
if (!vertex->off_screen)
tp->forced.n_visible++;
} else
node = *vertex->list_ptr;
node->forced_sides = forced_sides;
}
}
/*-
* Whether the addition of a tile of vtype on the given side of vertex
* would conform to the rules. The efficient way to do this would be
* to add the new tile and then use the same type of search as in
* match_rules. However, this function is not a performance
* bottleneck (only needed for random tile additions, which are
* relatively infrequent), so I will settle for a simpler implementation.
*/
static int
legal_move(fringe_node_c * vertex, unsigned side, vertex_type_c vtype)
{
rule_match_c hits[MAX_TILES_PER_VERTEX * N_VERTEX_RULES];
vertex_type_c legal_vt[MAX_COMPL];
int n_hits, n_legal, i;
n_hits = match_rules(vertex, hits, False);
n_legal = find_completions(vertex, hits, n_hits, side, legal_vt /*, False */ );
for (i = 0; i < n_legal; i++)
if (legal_vt[i] == vtype)
return True;
return False;
}
int filter_check (char *line, int direction)
{
if (rule_list.enabled == 0)
return -1;
struct ruleset *rule, *last = NULL, packet;
memset(&packet, 0, sizeof(packet));
char *from, *action, *to, *data;
char temp[1024];
strncpy(temp, line, 1023);
from = temp;
action = SeperateWord(from);
to = SeperateWord(action);
data = SeperateWord(to);
if (strempty(from))
return -1;
if (*from == ':')
from++;
packet.direction = direction;
strncpy(packet.from, from, NICKLEN);
if (action)
strncpy(packet.action, action, 128);
if (to)
strncpy(packet.to, to, NICKLEN);
if (data) {
if (*data == ':')
data++;
strncpy(packet.data, data, 1023);
}
for (rule = rule_list.ltail; rule; rule = rule->lprev) {
packet.rule = rule->rule;
if ((match_rules(rule, &packet)) == 1) {
last = rule;
if (rule->quick == 1)
return rule->rule;
}
}
if (last)
return last->rule;
return -1;
}
/*-
* Add a forced tile to a given forced vertex. Basically an easy job,
* since we know what to add. But it might fail if adding the tile
* would cause some untiled area to become enclosed. There is also another
* more exotic culprit: we might have a dislocation. Fortunately, they
* are very rare (the PRL article reported that perfect tilings of over
* 2^50 tiles had been generated). There is a version of the algorithm
* that doesn't produce dislocations, but it's a lot hairier than the
* simpler version I used.
*/
static int
add_forced_tile(ModeInfo * mi, forced_node_c * node)
{
tiling_c *tp = &tilings[MI_SCREEN(mi)];
unsigned side;
vertex_type_c vtype;
rule_match_c hits[MAX_TILES_PER_VERTEX * N_VERTEX_RULES];
int n;
if (node->forced_sides == (S_LEFT | S_RIGHT))
side = NRAND(2) ? S_LEFT : S_RIGHT;
else
side = node->forced_sides;
n = match_rules(node->vertex, hits, True);
n = find_completions(node->vertex, hits, n, side, &vtype /*, True */ );
if (n <= 0) {
tp->done = True;
if (MI_IS_VERBOSE(mi)) {
(void) fprintf(stderr, "Weirdness in add_forced_tile()\n");
(void) fprintf(stderr, "n = %d\n", n);
}
}
return add_tile(mi, node->vertex, side, vtype);
}
/*-
* Add a randomly chosen tile to a given vertex. This requires more checking
* as we must make sure the new tile conforms to the vertex rules at every
* vertex it touches. */
static void
add_random_tile(fringe_node_c * vertex, ModeInfo * mi)
{
fringe_node_c *right, *left, *far;
int i, j, n, n_hits, n_good;
unsigned side, fc, no_good, s;
vertex_type_c vtypes[MAX_COMPL];
rule_match_c hits[MAX_TILES_PER_VERTEX * N_VERTEX_RULES];
tiling_c *tp = &tilings[MI_SCREEN(mi)];
if (MI_NPIXELS(mi) > 2) {
tp->thick_color = NRAND(MI_NPIXELS(mi));
/* Insure good contrast */
tp->thin_color = (NRAND(2 * MI_NPIXELS(mi) / 3) + tp->thick_color +
MI_NPIXELS(mi) / 6) % MI_NPIXELS(mi);
} else {
unsigned long temp = tp->thick_color;
tp->thick_color = tp->thin_color;
tp->thin_color = temp;
}
n_hits = match_rules(vertex, hits, False);
side = NRAND(2) ? S_LEFT : S_RIGHT;
n = find_completions(vertex, hits, n_hits, side, vtypes /*, False */ );
/* One answer would mean a forced tile. */
if (n <= 0) {
tp->done = True;
if (MI_IS_VERBOSE(mi)) {
(void) fprintf(stderr, "Weirdness in add_random_tile()\n");
(void) fprintf(stderr, "n = %d\n", n);
}
}
no_good = 0;
n_good = n;
for (i = 0; i < n; i++) {
fc = fringe_changes(mi, vertex, side, vtypes[i], &right, &far, &left);
if (fc & FC_BAG) {
tp->done = True;
if (MI_IS_VERBOSE(mi)) {
(void) fprintf(stderr, "Weirdness in add_random_tile()\n");
(void) fprintf(stderr, "fc = %d, FC_BAG = %d\n", fc, FC_BAG);
}
}
if (right) {
s = (((fc & FC_CUT_FAR) && (fc & FC_CUT_LEFT)) ? S_RIGHT : S_LEFT);
if (!legal_move(right, s, VT_RIGHT(vtypes[i]))) {
no_good |= (1 << i);
n_good--;
continue;
}
}
if (left) {
s = (((fc & FC_CUT_FAR) && (fc & FC_CUT_RIGHT)) ? S_LEFT : S_RIGHT);
if (!legal_move(left, s, VT_LEFT(vtypes[i]))) {
no_good |= (1 << i);
n_good--;
continue;
}
}
if (far) {
s = ((fc & FC_CUT_LEFT) ? S_RIGHT : S_LEFT);
if (!legal_move(far, s, VT_FAR(vtypes[i]))) {
no_good |= (1 << i);
n_good--;
}
}
}
if (n_good <= 0) {
tp->done = True;
if (MI_IS_VERBOSE(mi)) {
(void) fprintf(stderr, "Weirdness in add_random_tile()\n");
(void) fprintf(stderr, "n_good = %d\n", n_good);
}
}
n = NRAND(n_good);
for (i = j = 0; i <= n; i++, j++)
while (no_good & (1 << j))
j++;
if (!add_tile(mi, vertex, side, vtypes[j - 1])) {
tp->done = True;
if (MI_IS_VERBOSE(mi)) {
(void) fprintf(stderr, "Weirdness in add_random_tile()\n");
}
free_penrose(tp);
}
}
