i.segment: use faster pavl tree

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@71705 15284696-431f-4ddb-bdfa-cd5b030d7da7

imagery/i.segment/Makefile

@@ -2,7 +2,7 @@ MODULE_TOPDIR = ../..
 
 PGM = i.segment
 
-LIBES = $(IMAGERYLIB) $(RASTERLIB) $(SEGMENTLIB) $(GISLIB) $(BTREE2LIB)
+LIBES = $(IMAGERYLIB) $(RASTERLIB) $(SEGMENTLIB) $(GISLIB)
 DEPENDENCIES = $(IMAGERYDEP) $(RASTERDEP) $(SEGMENTDEP) $(GISDEP)
 
 include $(MODULE_TOPDIR)/include/Make/Module.make

imagery/i.segment/mean_shift.c

@@ -10,7 +10,7 @@
 #include <grass/glocale.h>
 #include <grass/raster.h>
 #include <grass/segment.h>	/* segmentation library */
-#include <grass/rbtree.h>	/* Red Black Tree library functions */
+#include "pavl.h"
 #include "iseg.h"
 
 int remove_small_clumps(struct globals *globals);
@@ -418,6 +418,11 @@ static int cmp_rc(const void *first, const void *second)
     return (a->row - b->row);
 }
 
+static void free_item(void *p)
+{
+    G_free(p);
+}
+
 static int find_best_neighbour(struct globals *globals, int row, int col,
                                int this_id, struct NB_TREE *nbtree,
 			       int *reg_size, struct ngbr_stats **Rbest,
@@ -425,11 +430,11 @@ static int find_best_neighbour(struct globals *globals, int row, int col,
 {
     int rown, coln, n, count;
     int neighbors[8][2];
-    struct rc next, ngbr_rc;
+    struct rc next, ngbr_rc, *pngbr_rc;
     struct rclist rilist;
     int no_check;
     int ngbr_id;
-    struct RB_TREE *visited;
+    struct pavl_table *visited;
     struct ngbr_stats Ri, Rk, *Rfound;
     double sim, best_sim;
     int best_n_id;
@@ -441,10 +446,13 @@ static int find_best_neighbour(struct globals *globals, int row, int col,
     nbtree_clear(nbtree);
     FLAG_UNSET(globals->candidate_flag, row, col);
 
-    visited = rbtree_create(cmp_rc, sizeof(struct rc));
+    visited = pavl_create(cmp_rc, NULL);
     ngbr_rc.row = row;
     ngbr_rc.col = col;
-    rbtree_insert(visited, &ngbr_rc);
+    pngbr_rc = G_malloc(sizeof(struct rc));
+    *pngbr_rc = ngbr_rc;
+    pavl_insert(visited, pngbr_rc);
+    pngbr_rc = NULL;
 
     /* breadth-first search */
     next.row = row;
@@ -470,9 +478,12 @@ static int find_best_neighbour(struct globals *globals, int row, int col,
 
 	    ngbr_rc.row = rown;
 	    ngbr_rc.col = coln;
+	    if (pngbr_rc == NULL)
+		pngbr_rc = G_malloc(sizeof(struct rc));
+	    *pngbr_rc = ngbr_rc;
 
-	    if (!no_check && !rbtree_find(visited, &ngbr_rc)) {
-		rbtree_insert(visited, &ngbr_rc);
+	    if (!no_check && pavl_insert(visited, pngbr_rc) == NULL) {
+		pngbr_rc = NULL;
 
 		/* get neighbor ID */
 		Segment_get(&globals->rid_seg, (void *) &ngbr_id, rown, coln);
@@ -518,7 +529,9 @@ static int find_best_neighbour(struct globals *globals, int row, int col,
     } while (rclist_drop(&rilist, &next));   /* while there are cells to check */
 
     rclist_destroy(&rilist);
-    rbtree_destroy(visited);
+    if (pngbr_rc)
+	G_free(pngbr_rc);
+    pavl_destroy(visited, free_item);
     G_free(Ri.mean);
     G_free(Rk.mean);
     
@@ -534,8 +547,8 @@ static int check_reg_size(struct globals *globals, int minsize, int row, int col
     int this_id;
     int ngbr_id;
     LARGEINT reg_size;
-    struct RB_TREE *visited;
-    struct rc next, ngbr_rc;
+    struct pavl_table *visited;
+    struct rc next, ngbr_rc, *pngbr_rc;
     struct rclist rilist;
     int no_check;
     
@@ -544,10 +557,13 @@ static int check_reg_size(struct globals *globals, int minsize, int row, int col
 
     FLAG_UNSET(globals->candidate_flag, row, col);
 
-    visited = rbtree_create(cmp_rc, sizeof(struct rc));
+    visited = pavl_create(cmp_rc, NULL);
     ngbr_rc.row = row;
     ngbr_rc.col = col;
-    rbtree_insert(visited, &ngbr_rc);
+    pngbr_rc = G_malloc(sizeof(struct rc));
+    *pngbr_rc = ngbr_rc;
+    pavl_insert(visited, pngbr_rc);
+    pngbr_rc = NULL;
 
     /* get this ID */
     Segment_get(&globals->rid_seg, (void *) &this_id, row, col);
@@ -573,9 +589,12 @@ static int check_reg_size(struct globals *globals, int minsize, int row, int col
 
 	    ngbr_rc.row = rown;
 	    ngbr_rc.col = coln;
+	    if (pngbr_rc == NULL)
+		pngbr_rc = G_malloc(sizeof(struct rc));
+	    *pngbr_rc = ngbr_rc;
 
-	    if (!no_check && !rbtree_find(visited, &ngbr_rc)) {
-		rbtree_insert(visited, &ngbr_rc);
+	    if (!no_check && pavl_insert(visited, pngbr_rc) == NULL) {
+		pngbr_rc = NULL;
 
 		/* get neighbour ID */
 		Segment_get(&globals->rid_seg, (void *) &ngbr_id, rown, coln);
@@ -590,7 +609,9 @@ static int check_reg_size(struct globals *globals, int minsize, int row, int col
     } while (rclist_drop(&rilist, &next));   /* while there are cells to check */
 
     rclist_destroy(&rilist);
-    rbtree_destroy(visited);
+    if (pngbr_rc)
+	G_free(pngbr_rc);
+    pavl_destroy(visited, free_item);
 
     return reg_size;
 }

imagery/i.segment/pavl.c

@@ -0,0 +1,843 @@
+/* Produced by texiweb from libavl.w. */
+
+/* libavl - library for manipulation of binary trees.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software
+   Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.
+ */
+
+/* Nov 2016, Markus Metz
+ * from libavl-2.0.3
+ * added safety checks and speed optimizations
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "pavl.h"
+
+/* Creates and returns a new table
+   with comparison function |compare| using parameter |param|
+   and memory allocator |allocator|.
+   Returns |NULL| if memory allocation failed. */
+struct pavl_table *pavl_create(pavl_comparison_func * compare,
+			       struct libavl_allocator *allocator)
+{
+    struct pavl_table *tree;
+
+    assert(compare != NULL);
+
+    if (allocator == NULL)
+	allocator = &pavl_allocator_default;
+
+    tree = allocator->libavl_malloc(sizeof *tree);
+    if (tree == NULL)
+	return NULL;
+
+    tree->pavl_root = NULL;
+    tree->pavl_compare = compare;
+    tree->pavl_alloc = allocator;
+    tree->pavl_count = 0;
+
+    return tree;
+}
+
+/* Search |tree| for an item matching |item|, and return it if found.
+   Otherwise return |NULL|. */
+void *pavl_find(const struct pavl_table *tree, const void *item)
+{
+    const struct pavl_node *p;
+
+    assert(tree != NULL && item != NULL);
+
+    p = tree->pavl_root;
+    while (p != NULL) {
+	int cmp = tree->pavl_compare(item, p->pavl_data);
+
+	if (cmp == 0)
+	    return p->pavl_data;
+
+	p = p->pavl_link[cmp > 0];
+    }
+
+    return NULL;
+}
+
+/* Inserts |item| into |tree| and returns a pointer to |item|'s address.
+   If a duplicate item is found in the tree,
+   returns a pointer to the duplicate without inserting |item|.
+   Returns |NULL| in case of memory allocation failure. */
+void **pavl_probe(struct pavl_table *tree, void *item)
+{
+    struct pavl_node *y;	/* Top node to update balance factor, and parent. */
+    struct pavl_node *p, *q;	/* Iterator, and parent. */
+    struct pavl_node *n;	/* Newly inserted node. */
+    struct pavl_node *w;	/* New root of rebalanced subtree. */
+    int dir;			/* Direction to descend. */
+
+    assert(tree != NULL && item != NULL);
+
+    y = p = tree->pavl_root;
+    q = NULL;
+    dir = 0;
+    while (p != NULL) {
+	int cmp = tree->pavl_compare(item, p->pavl_data);
+
+	if (cmp == 0)
+	    return &p->pavl_data;
+
+	dir = cmp > 0;
+
+	if (p->pavl_balance != 0)
+	    y = p;
+
+	q = p, p = p->pavl_link[dir];
+    }
+
+    n = tree->pavl_alloc->libavl_malloc(sizeof *p);
+    if (n == NULL)
+	return NULL;
+
+    tree->pavl_count++;
+    n->pavl_link[0] = n->pavl_link[1] = NULL;
+    n->pavl_parent = q;
+    n->pavl_data = item;
+    n->pavl_balance = 0;
+    if (q == NULL) {
+	tree->pavl_root = n;
+
+	return &n->pavl_data;
+    }
+    q->pavl_link[dir] = n;
+
+    p = n;
+    while (p != y) {
+	q = p->pavl_parent;
+	/*
+	   dir = q->pavl_link[0] != p;
+	   if (dir == 0)
+	   q->pavl_balance--;
+	   else
+	   q->pavl_balance++;
+	 */
+	if (q->pavl_link[0] != p)
+	    q->pavl_balance++;
+	else
+	    q->pavl_balance--;
+
+	p = q;
+    }
+
+    if (y->pavl_balance == -2) {
+	struct pavl_node *x = y->pavl_link[0];
+
+	if (x->pavl_balance == -1) {
+	    w = x;
+	    y->pavl_link[0] = x->pavl_link[1];
+	    x->pavl_link[1] = y;
+	    x->pavl_balance = y->pavl_balance = 0;
+	    x->pavl_parent = y->pavl_parent;
+	    y->pavl_parent = x;
+	    if (y->pavl_link[0] != NULL)
+		y->pavl_link[0]->pavl_parent = y;
+	}
+	else {
+	    assert(x->pavl_balance == +1);
+	    w = x->pavl_link[1];
+	    x->pavl_link[1] = w->pavl_link[0];
+	    w->pavl_link[0] = x;
+	    y->pavl_link[0] = w->pavl_link[1];
+	    w->pavl_link[1] = y;
+	    if (w->pavl_balance == -1)
+		x->pavl_balance = 0, y->pavl_balance = +1;
+	    else if (w->pavl_balance == 0)
+		x->pavl_balance = y->pavl_balance = 0;
+	    else		/* |w->pavl_balance == +1| */
+		x->pavl_balance = -1, y->pavl_balance = 0;
+	    w->pavl_balance = 0;
+	    w->pavl_parent = y->pavl_parent;
+	    x->pavl_parent = y->pavl_parent = w;
+	    if (x->pavl_link[1] != NULL)
+		x->pavl_link[1]->pavl_parent = x;
+	    if (y->pavl_link[0] != NULL)
+		y->pavl_link[0]->pavl_parent = y;
+	}
+    }
+    else if (y->pavl_balance == +2) {
+	struct pavl_node *x = y->pavl_link[1];
+
+	if (x->pavl_balance == +1) {
+	    w = x;
+	    y->pavl_link[1] = x->pavl_link[0];
+	    x->pavl_link[0] = y;
+	    x->pavl_balance = y->pavl_balance = 0;
+	    x->pavl_parent = y->pavl_parent;
+	    y->pavl_parent = x;
+	    if (y->pavl_link[1] != NULL)
+		y->pavl_link[1]->pavl_parent = y;
+	}
+	else {
+	    assert(x->pavl_balance == -1);
+	    w = x->pavl_link[0];
+	    x->pavl_link[0] = w->pavl_link[1];
+	    w->pavl_link[1] = x;
+	    y->pavl_link[1] = w->pavl_link[0];
+	    w->pavl_link[0] = y;
+	    if (w->pavl_balance == +1)
+		x->pavl_balance = 0, y->pavl_balance = -1;
+	    else if (w->pavl_balance == 0)
+		x->pavl_balance = y->pavl_balance = 0;
+	    else		/* |w->pavl_balance == -1| */
+		x->pavl_balance = +1, y->pavl_balance = 0;
+	    w->pavl_balance = 0;
+	    w->pavl_parent = y->pavl_parent;
+	    x->pavl_parent = y->pavl_parent = w;
+	    if (x->pavl_link[0] != NULL)
+		x->pavl_link[0]->pavl_parent = x;
+	    if (y->pavl_link[1] != NULL)
+		y->pavl_link[1]->pavl_parent = y;
+	}
+    }
+    else
+	return &n->pavl_data;
+
+    if (w->pavl_parent != NULL)
+	w->pavl_parent->pavl_link[y != w->pavl_parent->pavl_link[0]] = w;
+    else
+	tree->pavl_root = w;
+
+    return &n->pavl_data;
+}
+
+/* Inserts |item| into |table|.
+   Returns |NULL| if |item| was successfully inserted
+   or if a memory allocation error occurred.
+   Otherwise, returns the duplicate item. */
+void *pavl_insert(struct pavl_table *table, void *item)
+{
+    void **p = pavl_probe(table, item);
+
+    return p == NULL || *p == item ? NULL : *p;
+}
+
+/* Inserts |item| into |table|, replacing any duplicate item.
+   Returns |NULL| if |item| was inserted without replacing a duplicate,
+   or if a memory allocation error occurred.
+   Otherwise, returns the item that was replaced. */
+void *pavl_replace(struct pavl_table *table, void *item)
+{
+    void **p = pavl_probe(table, item);
+
+    if (p == NULL || *p == item)
+	return NULL;
+    else {
+	void *r = *p;
+
+	*p = item;
+
+	return r;
+    }
+}
+
+/* Deletes from |tree| and returns an item matching |item|.
+   Returns a null pointer if no matching item found. */
+void *pavl_delete(struct pavl_table *tree, const void *item)
+{
+    struct pavl_node *p;	/* Traverses tree to find node to delete. */
+    struct pavl_node *q;	/* Parent of |p|. */
+    int dir;			/* Side of |q| on which |p| is linked. */
+    int cmp;			/* Result of comparison between |item| and |p|. */
+
+    assert(tree != NULL && item != NULL);
+
+    p = tree->pavl_root;
+    dir = 0;
+    while (p != NULL) {
+	cmp = tree->pavl_compare(item, p->pavl_data);
+
+	if (cmp == 0)
+	    break;
+
+	dir = cmp > 0;
+	p = p->pavl_link[dir];
+    }
+    if (p == NULL)
+	return NULL;
+
+    item = p->pavl_data;
+
+    q = p->pavl_parent;
+    if (q == NULL) {
+	q = (struct pavl_node *)&tree->pavl_root;
+	dir = 0;
+    }
+
+    if (p->pavl_link[1] == NULL) {
+	q->pavl_link[dir] = p->pavl_link[0];
+	if (q->pavl_link[dir] != NULL)
+	    q->pavl_link[dir]->pavl_parent = p->pavl_parent;
+    }
+    else {
+	struct pavl_node *r = p->pavl_link[1];
+
+	if (r->pavl_link[0] == NULL) {
+	    r->pavl_link[0] = p->pavl_link[0];
+	    q->pavl_link[dir] = r;
+	    r->pavl_parent = p->pavl_parent;
+	    if (r->pavl_link[0] != NULL)
+		r->pavl_link[0]->pavl_parent = r;
+	    r->pavl_balance = p->pavl_balance;
+	    q = r;
+	    dir = 1;
+	}
+	else {
+	    struct pavl_node *s = r->pavl_link[0];
+
+	    while (s->pavl_link[0] != NULL)
+		s = s->pavl_link[0];
+	    r = s->pavl_parent;
+	    r->pavl_link[0] = s->pavl_link[1];
+	    s->pavl_link[0] = p->pavl_link[0];
+	    s->pavl_link[1] = p->pavl_link[1];
+	    q->pavl_link[dir] = s;
+	    if (s->pavl_link[0] != NULL)
+		s->pavl_link[0]->pavl_parent = s;
+	    s->pavl_link[1]->pavl_parent = s;
+	    s->pavl_parent = p->pavl_parent;
+	    if (r->pavl_link[0] != NULL)
+		r->pavl_link[0]->pavl_parent = r;
+	    s->pavl_balance = p->pavl_balance;
+	    q = r;
+	    dir = 0;
+	}
+    }
+    tree->pavl_alloc->libavl_free(p);
+
+    while (q != (struct pavl_node *)&tree->pavl_root) {
+	struct pavl_node *y = q;
+
+	if (y->pavl_parent != NULL)
+	    q = y->pavl_parent;
+	else
+	    q = (struct pavl_node *)&tree->pavl_root;
+
+	if (dir == 0) {
+	    dir = q->pavl_link[0] != y;
+	    y->pavl_balance++;
+	    if (y->pavl_balance == +1)
+		break;
+	    else if (y->pavl_balance == +2) {
+		struct pavl_node *x = y->pavl_link[1];
+
+		if (x->pavl_balance == -1) {
+		    struct pavl_node *w;
+
+		    assert(x->pavl_balance == -1);
+		    w = x->pavl_link[0];
+		    x->pavl_link[0] = w->pavl_link[1];
+		    w->pavl_link[1] = x;
+		    y->pavl_link[1] = w->pavl_link[0];
+		    w->pavl_link[0] = y;
+		    if (w->pavl_balance == +1)
+			x->pavl_balance = 0, y->pavl_balance = -1;
+		    else if (w->pavl_balance == 0)
+			x->pavl_balance = y->pavl_balance = 0;
+		    else	/* |w->pavl_balance == -1| */
+			x->pavl_balance = +1, y->pavl_balance = 0;
+		    w->pavl_balance = 0;
+		    w->pavl_parent = y->pavl_parent;
+		    x->pavl_parent = y->pavl_parent = w;
+		    if (x->pavl_link[0] != NULL)
+			x->pavl_link[0]->pavl_parent = x;
+		    if (y->pavl_link[1] != NULL)
+			y->pavl_link[1]->pavl_parent = y;
+		    q->pavl_link[dir] = w;
+		}
+		else {
+		    y->pavl_link[1] = x->pavl_link[0];
+		    x->pavl_link[0] = y;
+		    x->pavl_parent = y->pavl_parent;
+		    y->pavl_parent = x;
+		    if (y->pavl_link[1] != NULL)
+			y->pavl_link[1]->pavl_parent = y;
+		    q->pavl_link[dir] = x;
+		    if (x->pavl_balance == 0) {
+			x->pavl_balance = -1;
+			y->pavl_balance = +1;
+			break;
+		    }
+		    else {
+			x->pavl_balance = y->pavl_balance = 0;
+			y = x;
+		    }
+		}
+	    }
+	}
+	else {
+	    dir = q->pavl_link[0] != y;
+	    y->pavl_balance--;
+	    if (y->pavl_balance == -1)
+		break;
+	    else if (y->pavl_balance == -2) {
+		struct pavl_node *x = y->pavl_link[0];
+
+		if (x->pavl_balance == +1) {
+		    struct pavl_node *w;
+
+		    assert(x->pavl_balance == +1);
+		    w = x->pavl_link[1];
+		    x->pavl_link[1] = w->pavl_link[0];
+		    w->pavl_link[0] = x;
+		    y->pavl_link[0] = w->pavl_link[1];
+		    w->pavl_link[1] = y;
+		    if (w->pavl_balance == -1)
+			x->pavl_balance = 0, y->pavl_balance = +1;
+		    else if (w->pavl_balance == 0)
+			x->pavl_balance = y->pavl_balance = 0;
+		    else	/* |w->pavl_balance == +1| */
+			x->pavl_balance = -1, y->pavl_balance = 0;
+		    w->pavl_balance = 0;
+		    w->pavl_parent = y->pavl_parent;
+		    x->pavl_parent = y->pavl_parent = w;
+		    if (x->pavl_link[1] != NULL)
+			x->pavl_link[1]->pavl_parent = x;
+		    if (y->pavl_link[0] != NULL)
+			y->pavl_link[0]->pavl_parent = y;
+		    q->pavl_link[dir] = w;
+		}
+		else {
+		    y->pavl_link[0] = x->pavl_link[1];
+		    x->pavl_link[1] = y;
+		    x->pavl_parent = y->pavl_parent;
+		    y->pavl_parent = x;
+		    if (y->pavl_link[0] != NULL)
+			y->pavl_link[0]->pavl_parent = y;
+		    q->pavl_link[dir] = x;
+		    if (x->pavl_balance == 0) {
+			x->pavl_balance = +1;
+			y->pavl_balance = -1;
+			break;
+		    }
+		    else {
+			x->pavl_balance = y->pavl_balance = 0;
+			y = x;
+		    }
+		}
+	    }
+	}
+    }
+
+    tree->pavl_count--;
+    return (void *)item;
+}
+
+/* Initializes |trav| for use with |tree|
+   and selects the null node. */
+void pavl_t_init(struct pavl_traverser *trav, struct pavl_table *tree)
+{
+    trav->pavl_table = tree;
+    trav->pavl_node = NULL;
+}
+
+/* Initializes |trav| for |tree|.
+   Returns data item in |tree| with the least value,
+   or |NULL| if |tree| is empty. */
+void *pavl_t_first(struct pavl_traverser *trav, struct pavl_table *tree)
+{
+    assert(tree != NULL && trav != NULL);
+
+    trav->pavl_table = tree;
+    trav->pavl_node = tree->pavl_root;
+    if (trav->pavl_node != NULL) {
+	while (trav->pavl_node->pavl_link[0] != NULL)
+	    trav->pavl_node = trav->pavl_node->pavl_link[0];
+
+	return trav->pavl_node->pavl_data;
+    }
+    else
+	return NULL;
+}
+
+/* Initializes |trav| for |tree|.
+   Returns data item in |tree| with the greatest value,
+   or |NULL| if |tree| is empty. */
+void *pavl_t_last(struct pavl_traverser *trav, struct pavl_table *tree)
+{
+    assert(tree != NULL && trav != NULL);
+
+    trav->pavl_table = tree;
+    trav->pavl_node = tree->pavl_root;
+    if (trav->pavl_node != NULL) {
+	while (trav->pavl_node->pavl_link[1] != NULL)
+	    trav->pavl_node = trav->pavl_node->pavl_link[1];
+
+	return trav->pavl_node->pavl_data;
+    }
+    else
+	return NULL;
+}
+
+/* Searches for |item| in |tree|.
+   If found, initializes |trav| to the item found and returns the item
+   as well.
+   If there is no matching item, initializes |trav| to the null item
+   and returns |NULL|. */
+void *pavl_t_find(struct pavl_traverser *trav, struct pavl_table *tree,
+		  void *item)
+{
+    struct pavl_node *p;
+
+    assert(trav != NULL && tree != NULL && item != NULL);
+
+    trav->pavl_table = tree;
+    
+    p = tree->pavl_root;
+    while (p != NULL) {
+	int cmp = tree->pavl_compare(item, p->pavl_data);
+
+	if (cmp == 0) {
+	    trav->pavl_node = p;
+
+	    return p->pavl_data;
+	}
+
+	p = p->pavl_link[cmp > 0];
+    }
+
+    trav->pavl_node = NULL;
+
+    return NULL;
+}
+
+/* Attempts to insert |item| into |tree|.
+   If |item| is inserted successfully, it is returned and |trav| is
+   initialized to its location.
+   If a duplicate is found, it is returned and |trav| is initialized to
+   its location.  No replacement of the item occurs.
+   If a memory allocation failure occurs, |NULL| is returned and |trav|
+   is initialized to the null item. */
+void *pavl_t_insert(struct pavl_traverser *trav,
+		    struct pavl_table *tree, void *item)
+{
+    void **p;
+
+    assert(trav != NULL && tree != NULL && item != NULL);
+
+    p = pavl_probe(tree, item);
+    if (p != NULL) {
+	trav->pavl_table = tree;
+	trav->pavl_node = ((struct pavl_node *)((char *)p -
+						offsetof(struct pavl_node,
+							 pavl_data)));
+
+	return *p;
+    }
+    else {
+	pavl_t_init(trav, tree);
+
+	return NULL;
+    }
+}
+
+/* Initializes |trav| to have the same current node as |src|. */
+void *pavl_t_copy(struct pavl_traverser *trav,
+		  const struct pavl_traverser *src)
+{
+    assert(trav != NULL && src != NULL);
+
+    trav->pavl_table = src->pavl_table;
+    trav->pavl_node = src->pavl_node;
+
+    return trav->pavl_node != NULL ? trav->pavl_node->pavl_data : NULL;
+}
+
+/* Returns the next data item in inorder
+   within the tree being traversed with |trav|,
+   or if there are no more data items returns |NULL|. */
+void *pavl_t_next(struct pavl_traverser *trav)
+{
+    assert(trav != NULL);
+
+    if (trav->pavl_node == NULL)
+	return pavl_t_first(trav, trav->pavl_table);
+    else if (trav->pavl_node->pavl_link[1] == NULL) {
+	struct pavl_node *q, *p;	/* Current node and its child. */
+
+	for (p = trav->pavl_node, q = p->pavl_parent;;
+	     p = q, q = q->pavl_parent)
+	    if (q == NULL || p == q->pavl_link[0]) {
+		trav->pavl_node = q;
+
+		return trav->pavl_node != NULL ?
+		    trav->pavl_node->pavl_data : NULL;
+	    }
+    }
+    else {
+	trav->pavl_node = trav->pavl_node->pavl_link[1];
+	while (trav->pavl_node->pavl_link[0] != NULL)
+	    trav->pavl_node = trav->pavl_node->pavl_link[0];
+
+	return trav->pavl_node->pavl_data;
+    }
+}
+
+/* Returns the previous data item in inorder
+   within the tree being traversed with |trav|,
+   or if there are no more data items returns |NULL|. */
+void *pavl_t_prev(struct pavl_traverser *trav)
+{
+    assert(trav != NULL);
+
+    if (trav->pavl_node == NULL)
+	return pavl_t_last(trav, trav->pavl_table);
+    else if (trav->pavl_node->pavl_link[0] == NULL) {
+	struct pavl_node *q, *p;	/* Current node and its child. */
+
+	for (p = trav->pavl_node, q = p->pavl_parent;;
+	     p = q, q = q->pavl_parent)
+	    if (q == NULL || p == q->pavl_link[1]) {
+		trav->pavl_node = q;
+
+		return trav->pavl_node != NULL ?
+		    trav->pavl_node->pavl_data : NULL;
+	    }
+    }
+    else {
+	trav->pavl_node = trav->pavl_node->pavl_link[0];
+	while (trav->pavl_node->pavl_link[1] != NULL)
+	    trav->pavl_node = trav->pavl_node->pavl_link[1];
+
+	return trav->pavl_node->pavl_data;
+    }
+}
+
+/* Returns |trav|'s current item. */
+void *pavl_t_cur(struct pavl_traverser *trav)
+{
+    assert(trav != NULL);
+
+    return trav->pavl_node != NULL ? trav->pavl_node->pavl_data : NULL;
+}
+
+/* Replaces the current item in |trav| by |new| and returns the item replaced.
+   |trav| must not have the null item selected.
+   The new item must not upset the ordering of the tree. */
+void *pavl_t_replace(struct pavl_traverser *trav, void *new)
+{
+    void *old;
+
+    assert(trav != NULL && trav->pavl_node != NULL && new != NULL);
+    old = trav->pavl_node->pavl_data;
+    trav->pavl_node->pavl_data = new;
+
+    return old;
+}
+
+/* Destroys |new| with |pavl_destroy (new, destroy)|,
+   first initializing right links in |new| that have
+   not yet been initialized at time of call. */
+static void
+copy_error_recovery(struct pavl_node *q,
+		    struct pavl_table *new, pavl_item_func * destroy)
+{
+    assert(q != NULL && new != NULL);
+
+    for (;;) {
+	struct pavl_node *p = q;
+
+	q = q->pavl_parent;
+	if (q == NULL)
+	    break;
+
+	if (p == q->pavl_link[0])
+	    q->pavl_link[1] = NULL;
+    }
+
+    pavl_destroy(new, destroy);
+}
+
+/* Copies |org| to a newly created tree, which is returned.
+   If |copy != NULL|, each data item in |org| is first passed to |copy|,
+   and the return values are inserted into the tree;
+   |NULL| return values are taken as indications of failure.
+   On failure, destroys the partially created new tree,
+   applying |destroy|, if non-null, to each item in the new tree so far,
+   and returns |NULL|.
+   If |allocator != NULL|, it is used for allocation in the new tree.
+   Otherwise, the same allocator used for |org| is used. */
+struct pavl_table *pavl_copy(const struct pavl_table *org,
+			     pavl_copy_func * copy, pavl_item_func * destroy,
+			     struct libavl_allocator *allocator)
+{
+    struct pavl_table *new;
+    const struct pavl_node *x;
+    struct pavl_node *y;
+
+    assert(org != NULL);
+    new = pavl_create(org->pavl_compare,
+		      allocator != NULL ? allocator : org->pavl_alloc);
+    if (new == NULL)
+	return NULL;
+
+    new->pavl_count = org->pavl_count;
+    if (new->pavl_count == 0)
+	return new;
+
+    x = (const struct pavl_node *)&org->pavl_root;
+    y = (struct pavl_node *)&new->pavl_root;
+    while (x != NULL) {
+	while (x->pavl_link[0] != NULL) {
+	    y->pavl_link[0] =
+		new->pavl_alloc->libavl_malloc(sizeof *y->pavl_link[0]);
+	    if (y->pavl_link[0] == NULL) {
+		if (y != (struct pavl_node *)&new->pavl_root) {
+		    y->pavl_data = NULL;
+		    y->pavl_link[1] = NULL;
+		}
+
+		copy_error_recovery(y, new, destroy);
+
+		return NULL;
+	    }
+	    y->pavl_link[0]->pavl_parent = y;
+
+	    x = x->pavl_link[0];
+	    y = y->pavl_link[0];
+	}
+	y->pavl_link[0] = NULL;
+
+	for (;;) {
+	    y->pavl_balance = x->pavl_balance;
+	    if (copy == NULL)
+		y->pavl_data = x->pavl_data;
+	    else {
+		y->pavl_data = copy(x->pavl_data);
+		if (y->pavl_data == NULL) {
+		    y->pavl_link[1] = NULL;
+		    copy_error_recovery(y, new, destroy);
+
+		    return NULL;
+		}
+	    }
+
+	    if (x->pavl_link[1] != NULL) {
+		y->pavl_link[1] =
+		    new->pavl_alloc->libavl_malloc(sizeof *y->pavl_link[1]);
+		if (y->pavl_link[1] == NULL) {
+		    copy_error_recovery(y, new, destroy);
+
+		    return NULL;
+		}
+		y->pavl_link[1]->pavl_parent = y;
+
+		x = x->pavl_link[1];
+		y = y->pavl_link[1];
+		break;
+	    }
+	    else
+		y->pavl_link[1] = NULL;
+
+	    for (;;) {
+		const struct pavl_node *w = x;
+
+		x = x->pavl_parent;
+		if (x == NULL) {
+		    new->pavl_root->pavl_parent = NULL;
+		    return new;
+		}
+		y = y->pavl_parent;
+
+		if (w == x->pavl_link[0])
+		    break;
+	    }
+	}
+    }
+
+    return new;
+}
+
+/* Frees storage allocated for |tree|.
+   If |destroy != NULL|, applies it to each data item in inorder. */
+void pavl_destroy(struct pavl_table *tree, pavl_item_func * destroy)
+{
+    struct pavl_node *p, *q;
+
+    assert(tree != NULL);
+
+    p = tree->pavl_root;
+    while (p != NULL) {
+	if (p->pavl_link[0] == NULL) {
+	    q = p->pavl_link[1];
+	    if (destroy != NULL && p->pavl_data != NULL)
+		destroy(p->pavl_data);
+	    tree->pavl_alloc->libavl_free(p);
+	}
+	else {
+	    q = p->pavl_link[0];
+	    p->pavl_link[0] = q->pavl_link[1];
+	    q->pavl_link[1] = p;
+	}
+	p = q;
+    }
+
+    tree->pavl_alloc->libavl_free(tree);
+}
+
+/* Allocates |size| bytes of space using |malloc()|.
+   Returns a null pointer if allocation fails. */
+void *pavl_malloc(size_t size)
+{
+    if (size > 0)
+	return malloc(size);
+
+    return NULL;
+}
+
+/* Frees |block|. */
+void pavl_free(void *block)
+{
+    if (block)
+	free(block);
+}
+
+/* Default memory allocator that uses |malloc()| and |free()|. */
+struct libavl_allocator pavl_allocator_default = {
+    pavl_malloc,
+    pavl_free
+};
+
+#undef NDEBUG
+#include <assert.h>
+
+/* Asserts that |pavl_insert()| succeeds at inserting |item| into |table|. */
+void (pavl_assert_insert) (struct pavl_table * table, void *item)
+{
+    void **p = pavl_probe(table, item);
+
+    assert(p != NULL && *p == item);
+}
+
+/* Asserts that |pavl_delete()| really removes |item| from |table|,
+   and returns the removed item. */
+void *(pavl_assert_delete) (struct pavl_table * table, void *item)
+{
+    void *p = pavl_delete(table, item);
+
+    assert(p != NULL);
+
+    return p;
+}

imagery/i.segment/pavl.h

@@ -0,0 +1,106 @@
+/* Produced by texiweb from libavl.w. */
+
+/* libavl - library for manipulation of binary trees.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software
+   Foundation, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 3 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301 USA.
+ */
+
+#ifndef PAVL_H
+#define PAVL_H 1
+
+#include <stddef.h>
+
+/* Function types. */
+typedef int pavl_comparison_func(const void *pavl_a, const void *pavl_b);
+typedef void pavl_item_func(void *pavl_item);
+typedef void *pavl_copy_func(void *pavl_item);
+
+#ifndef LIBAVL_ALLOCATOR
+#define LIBAVL_ALLOCATOR
+/* Memory allocator. */
+struct libavl_allocator
+{
+    void *(*libavl_malloc) (size_t libavl_size);
+    void (*libavl_free) (void *libavl_block);
+};
+#endif
+
+/* Default memory allocator. */
+extern struct libavl_allocator pavl_allocator_default;
+void *pavl_malloc(size_t);
+void pavl_free(void *);
+
+/* Maximum PAVL height, unused. */
+#ifndef PAVL_MAX_HEIGHT
+#define PAVL_MAX_HEIGHT 32
+#endif
+
+/* Tree data structure. */
+struct pavl_table
+{
+    struct pavl_node *pavl_root;	/* Tree's root. */
+    pavl_comparison_func *pavl_compare;	/* Comparison function. */
+    struct libavl_allocator *pavl_alloc;	/* Memory allocator. */
+    size_t pavl_count;		/* Number of items in tree. */
+};
+
+/* An PAVL tree node. */
+struct pavl_node
+{
+    struct pavl_node *pavl_link[2];	/* Subtrees. */
+    struct pavl_node *pavl_parent;	/* Parent node. */
+    void *pavl_data;		/* Pointer to data. */
+    signed char pavl_balance;	/* Balance factor. */
+};
+
+/* PAVL traverser structure. */
+struct pavl_traverser
+{
+    struct pavl_table *pavl_table;	/* Tree being traversed. */
+    struct pavl_node *pavl_node;	/* Current node in tree. */
+};
+
+/* Table functions. */
+struct pavl_table *pavl_create(pavl_comparison_func *,
+			       struct libavl_allocator *);
+struct pavl_table *pavl_copy(const struct pavl_table *, pavl_copy_func *,
+			     pavl_item_func *, struct libavl_allocator *);
+void pavl_destroy(struct pavl_table *, pavl_item_func *);
+void **pavl_probe(struct pavl_table *, void *);
+void *pavl_insert(struct pavl_table *, void *);
+void *pavl_replace(struct pavl_table *, void *);
+void *pavl_delete(struct pavl_table *, const void *);
+void *pavl_find(const struct pavl_table *, const void *);
+void pavl_assert_insert(struct pavl_table *, void *);
+void *pavl_assert_delete(struct pavl_table *, void *);
+
+#define pavl_count(table) ((size_t) (table)->pavl_count)
+
+/* Table traverser functions. */
+void pavl_t_init(struct pavl_traverser *, struct pavl_table *);
+void *pavl_t_first(struct pavl_traverser *, struct pavl_table *);
+void *pavl_t_last(struct pavl_traverser *, struct pavl_table *);
+void *pavl_t_find(struct pavl_traverser *, struct pavl_table *, void *);
+void *pavl_t_insert(struct pavl_traverser *, struct pavl_table *, void *);
+void *pavl_t_copy(struct pavl_traverser *, const struct pavl_traverser *);
+void *pavl_t_next(struct pavl_traverser *);
+void *pavl_t_prev(struct pavl_traverser *);
+void *pavl_t_cur(struct pavl_traverser *);
+void *pavl_t_replace(struct pavl_traverser *, void *);
+
+#endif /* pavl.h */

imagery/i.segment/region_growing.c

@@ -11,7 +11,7 @@
 #include <grass/glocale.h>
 #include <grass/raster.h>
 #include <grass/segment.h>	/* segmentation library */
-#include <grass/rbtree.h>	/* Red Black Tree library functions */
+#include "pavl.h"
 #include "iseg.h"
 
 #define EPSILON 1.0e-8
@@ -114,6 +114,11 @@ static int compare_rc(const void *first, const void *second)
 {
     struct rc *a = (struct rc *)first, *b = (struct rc *)second;
 
+    if (a->row == b->row)
+	return (a->col - b->col);
+    return (a->row - b->row);
+
+
     if (a->row < b->row)
 	return -1;
     if (a->row > b->row)
@@ -584,7 +589,7 @@ int region_growing(struct globals *globals)
 	    G_percent(row - globals->row_min,
 	              globals->row_max - globals->row_min, 4);
 	    for (col = globals->col_min; col < globals->col_max; col++) {
-		int do_merge = 1;
+		do_merge = 1;
 		
 		if (!(FLAG_GET(globals->candidate_flag, row, col)))
 		    continue;
@@ -672,6 +677,10 @@ int region_growing(struct globals *globals)
     return TRUE;
 }
 
+static void free_item(void *p)
+{
+    G_free(p);
+}
 
 static int find_best_neighbor(struct ngbr_stats *Ri,
 			      struct reg_stats *Ri_rs,
@@ -682,11 +691,11 @@ static int find_best_neighbor(struct ngbr_stats *Ri,
 			      struct globals *globals)
 {
     int n, n_ngbrs, no_check, cmp;
-    struct rc ngbr_rc, next;
+    struct rc ngbr_rc, next, *pngbr_rc;
     struct rclist rilist;
     double tempsim;
     int neighbors[8][2];
-    struct RB_TREE *no_check_tree;	/* cells already checked */
+    struct pavl_table *no_check_tree;	/* cells already checked */
     struct reg_stats *rs_found;
     int candk, candtmp;
 
@@ -703,10 +712,13 @@ static int find_best_neighbor(struct ngbr_stats *Ri,
 
     /* *** initialize data *** */
 
-    no_check_tree = rbtree_create(compare_rc, sizeof(struct rc));
     ngbr_rc.row = Ri->row;
     ngbr_rc.col = Ri->col;
-    rbtree_insert(no_check_tree, &ngbr_rc);
+    no_check_tree = pavl_create(compare_rc, NULL);
+    pngbr_rc = G_malloc(sizeof(struct rc));
+    *pngbr_rc = ngbr_rc;
+    pavl_insert(no_check_tree, pngbr_rc);
+    pngbr_rc = NULL;
 
     nbtree_clear(Ri_ngbrs);
     n_ngbrs = 0;
@@ -752,10 +764,12 @@ static int find_best_neighbor(struct ngbr_stats *Ri,
 
 		if (!no_check) {
 
-		    if (!rbtree_find(no_check_tree, &ngbr_rc)) {
+		    if (pngbr_rc == NULL)
+			pngbr_rc = G_malloc(sizeof(struct rc));
+		    *pngbr_rc = ngbr_rc;
 
-			/* not yet checked, don't check it again */
-			rbtree_insert(no_check_tree, &ngbr_rc);
+		    if (pavl_insert(no_check_tree, pngbr_rc) == NULL) {
+			pngbr_rc = NULL;
 
 			/* get neighbor ID */
 			Segment_get(&globals->rid_seg,
@@ -822,7 +836,9 @@ static int find_best_neighbor(struct ngbr_stats *Ri,
     } while (rclist_drop(&rilist, &next));   /* while there are cells to check */
 
     /* clean up */
-    rbtree_destroy(no_check_tree);
+    if (pngbr_rc)
+	G_free(pngbr_rc);
+    pavl_destroy(no_check_tree, free_item);
     rclist_destroy(&rilist);
 
     return n_ngbrs;
@@ -1031,17 +1047,21 @@ int update_band_vals(int row, int col, struct reg_stats *rs,
 	    G_fatal_error(_("Region size is larger than 2: %d"), count);
     }
     else if (rs->count > 2) {
-	struct RB_TREE *rc_check_tree;	/* cells already checked */
+	struct pavl_table *rc_check_tree;	/* cells already checked */
 	struct rclist rlist;
+	struct rc *pngbr_rc;
 	int no_check;
 
 	/* go through region, spreading outwards from head */
 	rclist_init(&rlist);
 
-	rc_check_tree = rbtree_create(compare_rc, sizeof(struct rc));
 	ngbr_rc.row = row;
 	ngbr_rc.col = col;
-	rbtree_insert(rc_check_tree, &ngbr_rc);
+	pngbr_rc = G_malloc(sizeof(struct rc));
+	*pngbr_rc = ngbr_rc;
+	rc_check_tree = pavl_create(compare_rc, NULL);
+	pavl_insert(rc_check_tree, pngbr_rc);
+	pngbr_rc = NULL;
 
 	next.row = row;
 	next.col = col;
@@ -1062,12 +1082,14 @@ int update_band_vals(int row, int col, struct reg_stats *rs,
 
 		if (!no_check) {
 		    if ((FLAG_GET(globals->null_flag, ngbr_rc.row, ngbr_rc.col)) == 0) {
-		    
-			/* already checked ? */
-			if (!rbtree_find(rc_check_tree, &ngbr_rc)) {
 
-			    /* not yet checked, don't check it again */
-			    rbtree_insert(rc_check_tree, &ngbr_rc);
+			if (pngbr_rc == NULL)
+			    pngbr_rc = G_malloc(sizeof(struct rc));
+			*pngbr_rc = ngbr_rc;
+
+			/* already checked ? */
+			if (pavl_insert(rc_check_tree, pngbr_rc) == NULL) {
+			    pngbr_rc = NULL;
 
 			    Segment_get(&globals->rid_seg, (void *) &rid,
 					ngbr_rc.row, ngbr_rc.col);
@@ -1090,7 +1112,9 @@ int update_band_vals(int row, int col, struct reg_stats *rs,
 	} while (rclist_drop(&rlist, &next));
 
 	/* clean up */
-	rbtree_destroy(rc_check_tree);
+	if (pngbr_rc)
+	    G_free(pngbr_rc);
+	pavl_destroy(rc_check_tree, free_item);
 	rclist_destroy(&rlist);
     }
     
@@ -1488,9 +1512,9 @@ static int calculate_reg_stats(int row, int col, struct reg_stats *rs,
     }
     else if (globals->min_reg_size > 3) {
 	/* rs->id must be set */
-	struct RB_TREE *rc_check_tree;	/* cells already checked */
+	struct pavl_table *rc_check_tree;	/* cells already checked */
 	int n, rid;
-	struct rc ngbr_rc, next;
+	struct rc ngbr_rc, *pngbr_rc, next;
 	struct rclist rilist;
 	int neighbors[8][2];
 	int no_check;
@@ -1498,10 +1522,13 @@ static int calculate_reg_stats(int row, int col, struct reg_stats *rs,
 	/* go through region, spreading outwards from head */
 	rclist_init(&rilist);
 
-	rc_check_tree = rbtree_create(compare_rc, sizeof(struct rc));
 	ngbr_rc.row = row;
 	ngbr_rc.col = col;
-	rbtree_insert(rc_check_tree, &ngbr_rc);
+	pngbr_rc = G_malloc(sizeof(struct rc));
+	*pngbr_rc = ngbr_rc;
+	rc_check_tree = pavl_create(compare_rc, NULL);
+	pavl_insert(rc_check_tree, pngbr_rc);
+	pngbr_rc = NULL;
 
 	next.row = row;
 	next.col = col;
@@ -1525,11 +1552,13 @@ static int calculate_reg_stats(int row, int col, struct reg_stats *rs,
 		if (!no_check) {
 		    if ((FLAG_GET(globals->null_flag, ngbr_rc.row, ngbr_rc.col)) == 0) {
 		    
-			/* already checked ? */
-			if (!rbtree_find(rc_check_tree, &ngbr_rc)) {
+			if (pngbr_rc == NULL)
+			    pngbr_rc = G_malloc(sizeof(struct rc));
+			*pngbr_rc = ngbr_rc;
 
-			    /* not yet checked, don't check it again */
-			    rbtree_insert(rc_check_tree, &ngbr_rc);
+			/* already checked ? */
+			if (pavl_insert(rc_check_tree, pngbr_rc) == NULL) {
+			    pngbr_rc = NULL;
 
 			    Segment_get(&globals->rid_seg, (void *) &rid,
 					ngbr_rc.row, ngbr_rc.col);
@@ -1549,7 +1578,9 @@ static int calculate_reg_stats(int row, int col, struct reg_stats *rs,
 	} while (rclist_drop(&rilist, &next));
 
 	/* clean up */
-	rbtree_destroy(rc_check_tree);
+	if (pngbr_rc)
+	    G_free(pngbr_rc);
+	pavl_destroy(rc_check_tree, free_item);
 	rclist_destroy(&rilist);
 
 	ret = 3;