static void make_adjacent( Segmenter *s, Region* r1, Region* r2 )
{
if( !is_adjacent( r1, r2 ) ){
if( r1->flags & SATURATED_REGION_FLAG ){
r2->flags |= FRAGMENTED_REGION_FLAG;
}else if( r2->flags & SATURATED_REGION_FLAG ){
r1->flags |= FRAGMENTED_REGION_FLAG;
}else{
if( r1->adjacent_region_count == s->max_adjacent_regions ){
make_saturated(r1);
r2->flags |= FRAGMENTED_REGION_FLAG;
if( r2->adjacent_region_count == s->max_adjacent_regions ){
make_saturated(r2);
r1->flags |= FRAGMENTED_REGION_FLAG;
}
}else if( r2->adjacent_region_count == s->max_adjacent_regions ){
make_saturated(r2);
r1->flags |= FRAGMENTED_REGION_FLAG;
}else{
assert( !(r1->flags & SATURATED_REGION_FLAG) );
assert( !(r2->flags & SATURATED_REGION_FLAG) );
assert( r1->adjacent_region_count < s->max_adjacent_regions );
assert( r2->adjacent_region_count < s->max_adjacent_regions );
r1->adjacent_regions[ r1->adjacent_region_count++ ] = r2;
r2->adjacent_regions[ r2->adjacent_region_count++ ] = r1;
}
}
}
// postcondition, adjacency link is bi-directional or isn't created
assert(
(r1_adjacent_contains_r2( r1, r2 ) && r1_adjacent_contains_r2( r2, r1 ))
||
(!r1_adjacent_contains_r2( r1, r2 ) && !r1_adjacent_contains_r2( r2, r1 ))
);
}
// merge r2 into r1 by first removing all common adjacencies from r2
// then transferring the remainder of adjacencies to r1 after discarding
// any excess adjacencies.
static void merge_regions( Segmenter *s, Region* r1, Region* r2 )
{
int i;
assert( r1 != r2 );
assert( !r1_adjacent_contains_r2( r1, r2 ) && !r1_adjacent_contains_r2( r2, r1 ) );
if( r1->flags & SATURATED_REGION_FLAG ){
make_saturated( r2 );
if( r2->flags & SATURATED_REGION_FLAG )
make_saturated( r1 );
}else if( r2->flags & SATURATED_REGION_FLAG ){
make_saturated( r1 );
}else{
// remove adjacencies of r2 which are already in r1
for( i = 0; i<r2->adjacent_region_count; ++i ){
Region *a = r2->adjacent_regions[i];
if( is_adjacent( a, r1 ) ){
remove_adjacent_from( a, r2 );
r2->adjacent_regions[i] = r2->adjacent_regions[ --r2->adjacent_region_count ];
}
}
if( r1->adjacent_region_count + r2->adjacent_region_count > s->max_adjacent_regions ){
make_saturated( r1 );
make_saturated( r2 );
}else{
// remove adjacencies from r2 and add them to r1
for( i=0; i < r2->adjacent_region_count; ++i ){
Region *a = r2->adjacent_regions[ i ];
replace_adjacent( a, r2, r1 ); // replace r2 with r1 in the adjacency list of a
r1->adjacent_regions[r1->adjacent_region_count++] = a;
assert( a->adjacent_region_count <= s->max_adjacent_regions );
assert( r1->adjacent_region_count <= s->max_adjacent_regions );
}
r2->adjacent_region_count = 0;
}
}
r1->flags |= r2->flags;
if( r2->left < r1->left )
r1->left = r2->left;
if( r2->top < r1->top )
r1->top = r2->top;
if( r2->right > r1->right )
r1->right = r2->right;
if( r2->bottom > r1->bottom )
r1->bottom = r2->bottom;
// postcondition: all adjacencies to r1 are bidirectional
#ifndef NDEBUG
for( i = 0; i < r1->adjacent_region_count; ++i ){
Region *a = r1->adjacent_regions[i];
assert( r1_adjacent_contains_r2( r1, a ) );
}
#endif
}
// recursively propagate descendent count and max depth upwards
// r->visit_counter is incremented each time we have an opportunity
// to traverse to a parent. we only actually visit it once the visit
// counter reaches adjacent_region_count - 1 i.e. that we have already
// visited all of its other children
// as we travel upwards we collect nodes with the constraints defined by
// min_target_root_descendent_count, max_target_root_descendent_count,
// min_depth and max_depth
// we never traverse above a node which exceeds these constraints. we also
// never traverse nodes which are saturated or fragmented because it is
// ambiguous whether such a node has a parent, or if all it's children are
// attched, and we can't determine this in a single pass (we could save a list
// of these nodes for a later pass but we don't bother.)
// during the calls to this function we store the maximum leaf-to-node depth
// in r->depth, later this field has a different meaning
static void propagate_descendent_count_and_max_depth_upwards(
Segmenter *s, Region *r, FidtrackerX *ft)
{
int i;
Region *parent = 0;
assert( r->level == NOT_TRAVERSED );
assert( r->children_visited_count == (r->adjacent_region_count - 1) // has an untraversed parent
|| r->children_visited_count == r->adjacent_region_count ); // is adjacent to root region
r->descendent_count = 0;
r->depth = 0;
r->level = TRAVERSING;
for( i=0; i < r->adjacent_region_count; ++i ){
Region *adjacent = r->adjacent_regions[i];
assert( r1_adjacent_contains_r2( adjacent, r ) );
if( adjacent->level == TRAVERSED ){
r->descendent_count += (short)(adjacent->descendent_count + 1);
r->depth = (short)MAX( r->depth, (adjacent->depth + 1) );
}else{
assert( parent == 0 );
parent = adjacent;
}
}
r->level = TRAVERSED;
if( r->descendent_count == ft->max_target_root_descendent_count
&& r->depth >= ft->min_depth && r->depth <= ft->max_depth ){
// found fiducial candidate
link_region( &ft->root_regions_head, r );
}else{
if( r->descendent_count >= ft->min_target_root_descendent_count
&& r->descendent_count < ft->max_target_root_descendent_count
&& r->depth >= ft->min_depth && r->depth <= ft->max_depth ) {
link_region( &ft->root_regions_head, r );
} else if( r->descendent_count >= ft->min_target_root_descendent_count-3
&& r->descendent_count < ft->max_target_root_descendent_count+3
&& r->depth >= ft->min_depth-1 && r->depth <= ft->max_depth+1 ) {
r->flags |= LOST_SYMBOL_FLAG;
link_region( &ft->root_regions_head, r );
}
if( parent
&& !(r->flags & ( SATURATED_REGION_FLAG |
ADJACENT_TO_ROOT_REGION_FLAG |
FREE_REGION_FLAG ) ) ){
++parent->children_visited_count;
if( r->descendent_count < ft->max_target_root_descendent_count
&& r->depth < ft->max_depth ){
// continue propagating depth and descendent count upwards
// so long as parent isn't a saturated node in which case it is
// ambiguous whether parent has a parent or not so we skip it
if(
!(parent->flags & SATURATED_REGION_FLAG)
&&
( ( (!(parent->flags & (ADJACENT_TO_ROOT_REGION_FLAG | FRAGMENTED_REGION_FLAG) )
&& parent->children_visited_count == (parent->adjacent_region_count - 1))
||
((parent->flags & (ADJACENT_TO_ROOT_REGION_FLAG | FRAGMENTED_REGION_FLAG) )
&& parent->children_visited_count == parent->adjacent_region_count) ) )
){
assert( r1_adjacent_contains_r2( r, parent ) );
assert( r1_adjacent_contains_r2( parent, r ) );
propagate_descendent_count_and_max_depth_upwards( s, parent, ft);
}
}
}
}
}
