[GRASS-SVN] r55273 - grass/trunk/vector/v.overlay
svn_grass at osgeo.org
svn_grass at osgeo.org
Fri Mar 1 12:40:53 PST 2013
Author: mmetz
Date: 2013-03-01 12:40:53 -0800 (Fri, 01 Mar 2013)
New Revision: 55273
Modified:
grass/trunk/vector/v.overlay/line_area.c
Log:
v.overlay: optimize line-area overlay
Modified: grass/trunk/vector/v.overlay/line_area.c
===================================================================
--- grass/trunk/vector/v.overlay/line_area.c 2013-03-01 15:42:16 UTC (rev 55272)
+++ grass/trunk/vector/v.overlay/line_area.c 2013-03-01 20:40:53 UTC (rev 55273)
@@ -14,6 +14,193 @@
#include <grass/glocale.h>
#include "local.h"
+/* compare category structures
+ * return 0 identical
+ * return 1 not identical
+ */
+static int compare_cats(struct line_cats *ACats, struct line_cats *BCats)
+{
+ int i, j;
+
+ if (ACats->n_cats == 0 || BCats->n_cats == 0) {
+ if (ACats->n_cats == 0 && BCats->n_cats == 0)
+ return 0;
+
+ if (ACats->n_cats == 0 && BCats->n_cats > 0)
+ return 1;
+
+ if (ACats->n_cats > 0 && BCats->n_cats == 0)
+ return 1;
+ }
+
+ for (i = 0; i < ACats->n_cats; i++) {
+ int found = 0;
+
+ for (j = 0; j < BCats->n_cats; j++) {
+ if (ACats->cat[i] == BCats->cat[j] &&
+ ACats->field[i] == BCats->field[j]) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found)
+ return 1;
+ }
+
+ return 0;
+}
+
+/* merge a given line with all other lines of the same type and
+ * with the same categories */
+static int merge_line(struct Map_info *Map, int line,
+ struct line_pnts *MPoints)
+{
+ int nlines, i, first, last, next_line, curr_line;
+ int merged = 0, newl = 0;
+ int next_node, direction, node_n_lines, type, ltype, lines_type;
+ static struct ilist *List = NULL;
+ static struct line_pnts *Points = NULL;
+ static struct line_cats *MCats = NULL, *Cats = NULL;
+ type = GV_LINE;
+
+ nlines = Vect_get_num_lines(Map);
+
+ if (!Points)
+ Points = Vect_new_line_struct();
+ if (!Cats)
+ Cats = Vect_new_cats_struct();
+ if (!MCats)
+ MCats = Vect_new_cats_struct();
+ if (!List)
+ List = Vect_new_list();
+
+ Vect_reset_line(Points);
+ Vect_reset_cats(Cats);
+ Vect_reset_cats(MCats);
+ Vect_reset_list(List);
+
+ if (!Vect_line_alive(Map, line))
+ return 0;
+
+ ltype = Vect_get_line_type(Map, line);
+
+ if (!(ltype & type))
+ return 0;
+
+ Vect_read_line(Map, NULL, MCats, line);
+
+ /* special cases:
+ * - loop back to start boundary via several other boundaries
+ * - one boundary forming closed loop
+ * - node with 3 entries but only 2 boundaries, one of them connecting twice,
+ * the other one must then be topologically incorrect in case of boundary */
+
+ /* go backward as long as there is only one other line/boundary at the current node */
+ G_debug(3, "go backward");
+ Vect_get_line_nodes(Map, line, &next_node, NULL);
+
+ first = -line;
+ while (1) {
+ node_n_lines = Vect_get_node_n_lines(Map, next_node);
+ /* count lines/boundaries at this node */
+ lines_type = 0;
+ next_line = first;
+ for (i = 0; i < node_n_lines; i++) {
+ curr_line = Vect_get_node_line(Map, next_node, i);
+ if ((Vect_get_line_type(Map, abs(curr_line)) & GV_LINES))
+ lines_type++;
+ if ((Vect_get_line_type(Map, abs(curr_line)) == ltype)) {
+ if (abs(curr_line) != abs(first)) {
+ Vect_read_line(Map, NULL, Cats, abs(curr_line));
+
+ /* catgories must be identical */
+ if (compare_cats(MCats, Cats) == 0)
+ next_line = curr_line;
+ }
+ }
+ }
+ if (lines_type == 2 && abs(next_line) != abs(first) &&
+ abs(next_line) != line) {
+ first = next_line;
+
+ if (first < 0) {
+ Vect_get_line_nodes(Map, -first, &next_node, NULL);
+ }
+ else {
+ Vect_get_line_nodes(Map, first, NULL, &next_node);
+ }
+ }
+ else
+ break;
+ }
+
+ /* go forward as long as there is only one other line/boundary at the current node */
+ G_debug(3, "go forward");
+
+ /* reverse direction */
+ last = -first;
+
+ if (last < 0) {
+ Vect_get_line_nodes(Map, -last, &next_node, NULL);
+ }
+ else {
+ Vect_get_line_nodes(Map, last, NULL, &next_node);
+ }
+
+ Vect_reset_list(List);
+ while (1) {
+ G_ilist_add(List, last);
+ node_n_lines = Vect_get_node_n_lines(Map, next_node);
+ lines_type = 0;
+ next_line = last;
+ for (i = 0; i < node_n_lines; i++) {
+ curr_line = Vect_get_node_line(Map, next_node, i);
+ if ((Vect_get_line_type(Map, abs(curr_line)) & GV_LINES))
+ lines_type++;
+ if ((Vect_get_line_type(Map, abs(curr_line)) == ltype)) {
+ if (abs(curr_line) != abs(last)) {
+ Vect_read_line(Map, NULL, Cats, abs(curr_line));
+
+ if (compare_cats(MCats, Cats) == 0)
+ next_line = curr_line;
+ }
+ }
+ }
+
+ if (lines_type == 2 && abs(next_line) != abs(last) &&
+ abs(next_line) != abs(first)) {
+ last = next_line;
+
+ if (last < 0) {
+ Vect_get_line_nodes(Map, -last, &next_node, NULL);
+ }
+ else {
+ Vect_get_line_nodes(Map, last, NULL, &next_node);
+ }
+ }
+ else
+ break;
+ }
+
+ /* merge lines */
+ G_debug(3, "merge %d lines", List->n_values);
+ Vect_reset_line(MPoints);
+
+ for (i = 0; i < List->n_values; i++) {
+ Vect_reset_line(Points);
+ Vect_read_line(Map, Points, Cats, abs(List->value[i]));
+ direction = (List->value[i] < 0 ? GV_BACKWARD : GV_FORWARD);
+ Vect_append_points(MPoints, Points, direction);
+ MPoints->n_points--;
+ Vect_delete_line(Map, abs(List->value[i]));
+ }
+ MPoints->n_points++;
+ merged += List->n_values;
+ newl++;
+
+ return merged;
+}
+
/* Check if point is inside area with category of given field. All cats are set in
* Cats with original field.
* returns number of cats.
@@ -69,8 +256,11 @@
G_message(_("Breaking lines..."));
Vect_break_lines_list(Tmp, NULL, BList, GV_LINE | GV_BOUNDARY, NULL);
+
+ /*
G_message(_("Merging lines..."));
Vect_merge_lines(Tmp, GV_LINE, NULL, NULL);
+ */
nlines = Vect_get_num_lines(Tmp);
@@ -117,6 +307,9 @@
* This should not happen if Vect_break_lines_list() works correctly
*/
+ /* merge here */
+ merge_line(Tmp, line, Points);
+
G_debug(3, "line = %d", line);
point_area(&(In[1]), field[1], (Points->x[0] + Points->x[1]) / 2,
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