3 typedef struct Edge Edge;
4 typedef struct EdgeEnd EdgeEnd;
5 typedef struct Node Node;
6 typedef struct NodeSideRef NodeSideRef;
9 EdgeNode *back, *next; /* other ends at same side of same node */
10 Edge *edge; /* edge->ends[end].edge==edge */
11 int end; /* edge->ends[end].edge==end */
17 const char *segment, *movfeatpos;
22 Node *node; /* node->edges[side].node==node */
23 int side; /* node->edges[side].side==side */
32 static Node *nodes_head, *nodes_tail;
34 static void extendsplits(void) {
36 * Whenever we have a node which has one or more moveable feature
37 * subsegments, part of the same moveable feature, on one side, and
38 * fixed portion of the same segment on the other, we eliminate
39 * the fixed portion and add its length to both the moveables,
40 * so that we have one subsegspec for the whole of each position:
42 * <---l---> <----l'---> <---------(l+l')------>
44 * *----A1---*----A1/P0--* becomes *--------A1/P0----------*
45 * `---A1/P1---* `-------A1/P1-----------*
47 * <----l''---> <---------(l+l'')------>
52 for (node=nodes_head; node; node=node->next) {
53 for (rightside=0; rightside<2; rightside++) {
54 trace("extendsplit pass %d node ",pass); trace_node(node);
55 trace("/%d ",rightside);
56 if ((n= count_edges(&node->sides[!rightside])) != 1) {
57 trace("no: lhs edges=%d\n", n);
60 leftedge= node->sides[!rightside].head;
61 if (leftedge->edge->movfeatpos) {
62 trace("no: lhs moveable\n");
65 if (!node->sides[rightside].head) {
66 trace("no: rhs absent\n");
69 for (rightedge= node->sides[rightside].head;
71 rightedge= rightedge->next) {
72 if (!rightedge->edge->movfeatpos) {
73 trace("no: rhs fixed ("); trace_edgeend(rightedge); trace(")\n");
76 if (strcmp(leftedge->edge->segment, rightedge->edge->segment)) {
77 trace("no: lhs seg %s, rhs seg %s (",
78 leftedge->edge->segment
79 rightedge->edge->segment);
80 trace_edgeend(rightedge); trace(")\n");
92 trace("yes, lhs "); trace_edgeend(leftedge); trace(":\n");
93 for (rightedge= node->sides[rightside].head;
95 rightedge= rightedge->next) {
96 rightedge->edge->distance += leftedge->edge->distance;
97 edge_replumb(rightedge, edgeend_otherend(leftedge)->node);
99 edge_delete(leftedge->edge);
100 node_surely_orphaned(node);
101 trace(" extendsplit operation complete\n");
105 static EdgeEnd *edgeend_otherend(EdgeEnd *thisend) {
106 return &thisend->edge->ends[!thisend->end];
109 static void elimtrivial(void) {
110 /* Eliminate trivial nodes: ones which have only two edges, which
111 * come in on opposite sides, have the same subsegspec, and with the
112 * two ends identically aligned.
114 for (node=nodes_head; node; node=next_node) {
115 next_node=node->next;
116 trace("elimtrivial node "); trace_node(node); trace(" ");
117 if (!(count_edges(&node->sides[0])==1 &&
118 count_edges(&node->sides[1])==1)) {
119 trace("no, a non-unitary side\n");
122 leftedge= node->sides[0].head;
123 rightedge= node->sides[0].head;
124 if (strcmp(leftedge->edge.segment,rightedge->edge.segment)) {
125 trace("no, segments differ\n");
128 if (!!leftedge->edge.movfeatpos != !!rightedge->edge.movfeatpos ||
129 strcmp(leftedge->edge.movfeatpos, rightedge->edge.movfeatpos)) {
130 trace("no, movfeatpos's differ\n");
133 if (leftedge->end == rightedge->end) {
134 trace("no, opposite alignment\n");
138 rightedge->edge->distance += leftedge->edge->distance;
139 edge_replumb(rightedge, edgeend_otherend(leftedge)->node);
140 edge_delete(leftedge->edge);
141 node_surely_orphaned(node);
142 trace(" elimtrivial operation complete\n");