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-rw-r--r--src/backend/utils/adt/geo-ops.c1947
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diff --git a/src/backend/utils/adt/geo-ops.c b/src/backend/utils/adt/geo-ops.c
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+++ b/src/backend/utils/adt/geo-ops.c
@@ -0,0 +1,1947 @@
+/*-------------------------------------------------------------------------
+ *
+ * geo-ops.c--
+ * 2D geometric operations
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/Attic/geo-ops.c,v 1.1.1.1 1996/07/09 06:22:04 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <math.h>
+#include <float.h> /* faked on sunos */
+#include <stdio.h> /* for sprintf proto, etc. */
+#include <string.h>
+
+#include "utils/geo-decls.h"
+#include "utils/elog.h"
+#include "utils/palloc.h"
+
+#define LDELIM '('
+#define RDELIM ')'
+#define DELIM ','
+#define BOXNARGS 4
+#define LSEGNARGS 4
+#define POINTNARGS 2
+
+/***********************************************************************
+ **
+ ** Routines for two-dimensional boxes.
+ **
+ ***********************************************************************/
+
+/*----------------------------------------------------------
+ * Formatting and conversion routines.
+ *---------------------------------------------------------*/
+
+/* box_in - convert a string to internal form.
+ *
+ * str: input string "(f8, f8, f8, f8)"
+ */
+BOX *box_in(char *str)
+{
+ double tmp;
+ char *p, *coord[BOXNARGS];
+ int i;
+ BOX *result;
+
+ if (str == NULL)
+ elog (WARN," Bad (null) box external representation");
+
+ if ((p = (char *)strchr(str, LDELIM)) == (char *)NULL)
+ elog (WARN, "Bad box external representation '%s'",str);
+ for (i = 0, p = str; *p && i < BOXNARGS && *p != RDELIM; p++)
+ if (*p == DELIM || (*p == LDELIM && !i))
+ coord[i++] = p + 1;
+ if (i < BOXNARGS - 1)
+ elog (WARN, "Bad box external representation '%s'", str);
+ result = PALLOCTYPE(BOX);
+ result->xh = atof(coord[0]);
+ result->yh = atof(coord[1]);
+ result->xl = atof(coord[2]);
+ result->yl = atof(coord[3]);
+ if (result->xh < result->xl) {
+ tmp = result->xh;
+ result->xh = result->xl;
+ result->xl = tmp;
+ }
+ if (result->yh < result->yl) {
+ tmp = result->yh;
+ result->yh = result->yl;
+ result->yl = tmp;
+ }
+
+ return(result);
+}
+
+/* box_out - convert a box to external form.
+ */
+char *box_out(BOX *box)
+{
+ char *result;
+
+ if (box == NULL)
+ return(NULL);
+ result = (char *)PALLOC(80);
+ (void) sprintf(result, "(%G,%G,%G,%G)",
+ box->xh, box->yh, box->xl, box->yl);
+
+ return(result);
+}
+
+
+/* box_construct - fill in a new box.
+ */
+BOX *box_construct(double x1, double x2, double y1, double y2)
+{
+ BOX *result;
+
+ result = PALLOCTYPE(BOX);
+ return( box_fill(result, x1, x2, y1, y2) );
+}
+
+
+/* box_fill - fill in a static box
+ */
+BOX *box_fill(BOX *result, double x1, double x2, double y1, double y2)
+{
+ double tmp;
+
+ result->xh = x1;
+ result->xl = x2;
+ result->yh = y1;
+ result->yl = y2;
+ if (result->xh < result->xl) {
+ tmp = result->xh;
+ result->xh = result->xl;
+ result->xl = tmp;
+ }
+ if (result->yh < result->yl) {
+ tmp = result->yh;
+ result->yh = result->yl;
+ result->yl = tmp;
+ }
+
+ return(result);
+}
+
+
+/* box_copy - copy a box
+ */
+BOX *box_copy(BOX *box)
+{
+ BOX *result;
+
+ result = PALLOCTYPE(BOX);
+ memmove((char *) result, (char *) box, sizeof(BOX));
+
+ return(result);
+}
+
+
+/*----------------------------------------------------------
+ * Relational operators for BOXes.
+ * <, >, <=, >=, and == are based on box area.
+ *---------------------------------------------------------*/
+
+/* box_same - are two boxes identical?
+ */
+long box_same(BOX *box1, BOX *box2)
+{
+ return((box1->xh == box2->xh && box1->xl == box2->xl) &&
+ (box1->yh == box2->yh && box1->yl == box2->yl));
+}
+
+/* box_overlap - does box1 overlap box2?
+ */
+long box_overlap(BOX *box1, BOX *box2)
+{
+ return(((box1->xh >= box2->xh && box1->xl <= box2->xh) ||
+ (box2->xh >= box1->xh && box2->xl <= box1->xh)) &&
+ ((box1->yh >= box2->yh && box1->yl <= box2->yh) ||
+ (box2->yh >= box1->yh && box2->yl <= box1->yh)) );
+}
+
+/* box_overleft - is the right edge of box1 to the left of
+ * the right edge of box2?
+ *
+ * This is "less than or equal" for the end of a time range,
+ * when time ranges are stored as rectangles.
+ */
+long box_overleft(BOX *box1, BOX *box2)
+{
+ return(box1->xh <= box2->xh);
+}
+
+/* box_left - is box1 strictly left of box2?
+ */
+long box_left(BOX *box1, BOX *box2)
+{
+ return(box1->xh < box2->xl);
+}
+
+/* box_right - is box1 strictly right of box2?
+ */
+long box_right(BOX *box1, BOX *box2)
+{
+ return(box1->xl > box2->xh);
+}
+
+/* box_overright - is the left edge of box1 to the right of
+ * the left edge of box2?
+ *
+ * This is "greater than or equal" for time ranges, when time ranges
+ * are stored as rectangles.
+ */
+long box_overright(BOX *box1, BOX *box2)
+{
+ return(box1->xl >= box2->xl);
+}
+
+/* box_contained - is box1 contained by box2?
+ */
+long box_contained(BOX *box1, BOX *box2)
+{
+ return((box1->xh <= box2->xh && box1->xl >= box2->xl &&
+ box1->yh <= box2->yh && box1->yl >= box2->yl));
+}
+
+/* box_contain - does box1 contain box2?
+ */
+long box_contain(BOX *box1, BOX *box2)
+{
+ return((box1->xh >= box2->xh && box1->xl <= box2->xl &&
+ box1->yh >= box2->yh && box1->yl <= box2->yl));
+}
+
+
+/* box_positionop -
+ * is box1 entirely {above, below } box2?
+ */
+long box_below(BOX *box1, BOX *box2)
+{
+ return( box1->yh <= box2->yl );
+}
+
+long box_above(BOX *box1, BOX *box2)
+{
+ return( box1->yl >= box2->yh );
+}
+
+
+/* box_relop - is area(box1) relop area(box2), within
+ * our accuracy constraint?
+ */
+long box_lt(BOX *box1, BOX *box2)
+{
+ return( FPlt(box_ar(box1), box_ar(box2)) );
+}
+
+long box_gt(BOX *box1, BOX *box2)
+{
+ return( FPgt(box_ar(box1), box_ar(box2)) );
+}
+
+long box_eq(BOX *box1, BOX *box2)
+{
+ return( FPeq(box_ar(box1), box_ar(box2)) );
+}
+
+long box_le(BOX *box1, BOX *box2)
+{
+ return( FPle(box_ar(box1), box_ar(box2)) );
+}
+
+long box_ge(BOX *box1, BOX *box2)
+{
+ return( FPge(box_ar(box1), box_ar(box2)) );
+}
+
+
+/*----------------------------------------------------------
+ * "Arithmetic" operators on boxes.
+ * box_foo returns foo as an object (pointer) that
+ can be passed between languages.
+ * box_xx is an internal routine which returns the
+ * actual value (and cannot be handed back to
+ * LISP).
+ *---------------------------------------------------------*/
+
+/* box_area - returns the area of the box.
+ */
+double *box_area(BOX *box)
+{
+ double *result;
+
+ result = PALLOCTYPE(double);
+ *result = box_ln(box) * box_ht(box);
+
+ return(result);
+}
+
+
+/* box_length - returns the length of the box
+ * (horizontal magnitude).
+ */
+double *box_length(BOX *box)
+{
+ double *result;
+
+ result = PALLOCTYPE(double);
+ *result = box->xh - box->xl;
+
+ return(result);
+}
+
+
+/* box_height - returns the height of the box
+ * (vertical magnitude).
+ */
+double *box_height(BOX *box)
+{
+ double *result;
+
+ result = PALLOCTYPE(double);
+ *result = box->yh - box->yl;
+
+ return(result);
+}
+
+
+/* box_distance - returns the distance between the
+ * center points of two boxes.
+ */
+double *box_distance(BOX *box1, BOX *box2)
+{
+ double *result;
+ Point *box_center(), *a, *b;
+
+ result = PALLOCTYPE(double);
+ a = box_center(box1);
+ b = box_center(box2);
+ *result = HYPOT(a->x - b->x, a->y - b->y);
+
+ PFREE(a);
+ PFREE(b);
+ return(result);
+}
+
+
+/* box_center - returns the center point of the box.
+ */
+Point *box_center(BOX *box)
+{
+ Point *result;
+
+ result = PALLOCTYPE(Point);
+ result->x = (box->xh + box->xl) / 2.0;
+ result->y = (box->yh + box->yl) / 2.0;
+
+ return(result);
+}
+
+
+/* box_ar - returns the area of the box.
+ */
+double box_ar(BOX *box)
+{
+ return( box_ln(box) * box_ht(box) );
+}
+
+
+/* box_ln - returns the length of the box
+ * (horizontal magnitude).
+ */
+double box_ln(BOX *box)
+{
+ return( box->xh - box->xl );
+}
+
+
+/* box_ht - returns the height of the box
+ * (vertical magnitude).
+ */
+double box_ht(BOX *box)
+{
+ return( box->yh - box->yl );
+}
+
+
+/* box_dt - returns the distance between the
+ * center points of two boxes.
+ */
+double box_dt(BOX *box1, BOX *box2)
+{
+ double result;
+ Point *box_center(),
+ *a, *b;
+
+ a = box_center(box1);
+ b = box_center(box2);
+ result = HYPOT(a->x - b->x, a->y - b->y);
+
+ PFREE(a);
+ PFREE(b);
+ return(result);
+}
+
+/*----------------------------------------------------------
+ * Funky operations.
+ *---------------------------------------------------------*/
+
+/* box_intersect -
+ * returns the overlapping portion of two boxes,
+ * or NULL if they do not intersect.
+ */
+BOX *box_intersect(BOX *box1, BOX *box2)
+{
+ BOX *result;
+ long box_overlap();
+
+ if (! box_overlap(box1,box2))
+ return(NULL);
+ result = PALLOCTYPE(BOX);
+ result->xh = Min(box1->xh, box2->xh);
+ result->xl = Max(box1->xl, box2->xl);
+ result->yh = Min(box1->yh, box2->yh);
+ result->yl = Max(box1->yl, box2->yl);
+
+ return(result);
+}
+
+
+/* box_diagonal -
+ * returns a line segment which happens to be the
+ * positive-slope diagonal of "box".
+ * provided, of course, we have LSEGs.
+ */
+LSEG *box_diagonal(BOX *box)
+{
+ Point p1, p2;
+
+ p1.x = box->xh;
+ p1.y = box->yh;
+ p2.x = box->xl;
+ p2.y = box->yl;
+ return( lseg_construct( &p1, &p2 ) );
+
+}
+
+/***********************************************************************
+ **
+ ** Routines for 2D lines.
+ ** Lines are not intended to be used as ADTs per se,
+ ** but their ops are useful tools for other ADT ops. Thus,
+ ** there are few relops.
+ **
+ ***********************************************************************/
+
+/*----------------------------------------------------------
+ * Conversion routines from one line formula to internal.
+ * Internal form: Ax+By+C=0
+ *---------------------------------------------------------*/
+
+LINE * /* point-slope */
+line_construct_pm(Point *pt, double m)
+{
+ LINE *result;
+
+ result = PALLOCTYPE(LINE);
+ /* use "mx - y + yinter = 0" */
+ result->A = m;
+ result->B = -1.0;
+ result->C = pt->y - m * pt->x;
+ return(result);
+}
+
+
+LINE * /* two points */
+line_construct_pp(Point *pt1, Point *pt2)
+{
+ LINE *result;
+
+ result = PALLOCTYPE(LINE);
+ if (FPeq(pt1->x, pt2->x)) { /* vertical */
+ /* use "x = C" */
+ result->m = 0.0;
+ result->A = -1.0;
+ result->B = 0.0;
+ result->C = pt1->x;
+ } else {
+ /* use "mx - y + yinter = 0" */
+ result->m = (pt1->y - pt2->y) / (pt1->x - pt2->x);
+ result->A = result->m;
+ result->B = -1.0;
+ result->C = pt1->y - result->m * pt1->x;
+ }
+ return(result);
+}
+
+
+/*----------------------------------------------------------
+ * Relative position routines.
+ *---------------------------------------------------------*/
+
+long line_intersect(LINE *l1, LINE *l2)
+{
+ return( ! line_parallel(l1, l2) );
+}
+
+long line_parallel(LINE *l1, LINE *l2)
+{
+ return( FPeq(l1->m, l2->m) );
+}
+
+long line_perp(LINE *l1, LINE *l2)
+{
+ if (l1->m)
+ return( FPeq(l2->m / l1->m, -1.0) );
+ else if (l2->m)
+ return( FPeq(l1->m / l2->m, -1.0) );
+ return(1); /* both 0.0 */
+}
+
+long line_vertical(LINE *line)
+{
+ return( FPeq(line->A, -1.0) && FPzero(line->B) );
+}
+
+long line_horizontal(LINE *line)
+{
+ return( FPzero(line->m) );
+}
+
+
+long line_eq(LINE *l1, LINE *l2)
+{
+ double k;
+
+ if (! FPzero(l2->A))
+ k = l1->A / l2->A;
+ else if (! FPzero(l2->B))
+ k = l1->B / l2->B;
+ else if (! FPzero(l2->C))
+ k = l1->C / l2->C;
+ else
+ k = 1.0;
+ return( FPeq(l1->A, k * l2->A) &&
+ FPeq(l1->B, k * l2->B) &&
+ FPeq(l1->C, k * l2->C) );
+}
+
+
+/*----------------------------------------------------------
+ * Line arithmetic routines.
+ *---------------------------------------------------------*/
+
+double * /* distance between l1, l2 */
+line_distance(LINE *l1, LINE *l2)
+{
+ double *result;
+ Point *tmp;
+
+ result = PALLOCTYPE(double);
+ if (line_intersect(l1, l2)) {
+ *result = 0.0;
+ return(result);
+ }
+ if (line_vertical(l1))
+ *result = fabs(l1->C - l2->C);
+ else {
+ tmp = point_construct(0.0, l1->C);
+ result = dist_pl(tmp, l2);
+ PFREE(tmp);
+ }
+ return(result);
+}
+
+Point * /* point where l1, l2 intersect (if any) */
+line_interpt(LINE *l1, LINE *l2)
+{
+ Point *result;
+ double x;
+
+ if (line_parallel(l1, l2))
+ return(NULL);
+ if (line_vertical(l1))
+ result = point_construct(l2->m * l1->C + l2->C, l1->C);
+ else if (line_vertical(l2))
+ result = point_construct(l1->m * l2->C + l1->C, l2->C);
+ else {
+ x = (l1->C - l2->C) / (l2->A - l1->A);
+ result = point_construct(x, l1->m * x + l1->C);
+ }
+ return(result);
+}
+
+/***********************************************************************
+ **
+ ** Routines for 2D paths (sequences of line segments, also
+ ** called `polylines').
+ **
+ ** This is not a general package for geometric paths,
+ ** which of course include polygons; the emphasis here
+ ** is on (for example) usefulness in wire layout.
+ **
+ ***********************************************************************/
+
+#define PATHALLOCSIZE(N) \
+ (long) ((unsigned) (sizeof(PATH) + \
+ (((N)-1) > 0 ? ((N)-1) : 0) \
+ * sizeof(Point)))
+
+/*----------------------------------------------------------
+ * String to path / path to string conversion.
+ * External format:
+ * "(closed, npts, xcoord, ycoord,... )"
+ *---------------------------------------------------------*/
+
+PATH *path_in(char *str)
+{
+ double coord;
+ long field[2];
+ char *s;
+ int ct, i;
+ PATH *result;
+ long pathsize;
+
+ if (str == NULL)
+ elog(WARN, "Bad (null) path external representation");
+
+ /* read the path header information */
+ for (i = 0, s = str; *s && i < 2 && *s != RDELIM; ++s)
+ if (*s == DELIM || (*s == LDELIM && !i))
+ field[i++] = atol(s + 1);
+ if (i < 1)
+ elog(WARN, "Bad path external representation '%s'", str);
+ pathsize = PATHALLOCSIZE(field[1]);
+ result = (PATH *)palloc(pathsize);
+ result->length = pathsize;
+ result->closed = field[0];
+ result->npts = field[1];
+
+ /* read the path points */
+
+ ct = result->npts * 2; /* two coords for every point */
+ for (i = 0;
+ *s && i < ct && *s != RDELIM;
+ ++s) {
+ if (*s == ',') {
+ coord = atof(s + 1);
+ if (i % 2)
+ (result->p[i/2]).y = coord;
+ else
+ (result->p[i/2]).x = coord;
+ ++i;
+ }
+ }
+ if (i % 2 || i < --ct) {
+ PFREE(result);
+ elog(WARN, "Bad path external representation '%s'", str);
+ }
+
+ return(result);
+}
+
+
+char *path_out(PATH *path)
+{
+ char buf[BUFSIZ + 20000], *result, *s;
+ int i;
+ char tmp[64];
+
+ if (path == NULL)
+ return(NULL);
+ (void) sprintf(buf,"%c%d,%d", LDELIM,
+ path->closed, path->npts);
+ s = buf + strlen(buf);
+ for (i = 0; i < path->npts; ++i) {
+ (void) sprintf(tmp, ",%G,%G",
+ path->p[i].x, path->p[i].y);
+ (void) strcpy(s, tmp);
+ s += strlen(tmp);
+ }
+ *s++ = RDELIM;
+ *s = '\0';
+ result = (char *)PALLOC(strlen(buf) + 1);
+ (void) strcpy(result, buf);
+
+ return(result);
+}
+
+
+/*----------------------------------------------------------
+ * Relational operators.
+ * These are based on the path cardinality,
+ * as stupid as that sounds.
+ *
+ * Better relops and access methods coming soon.
+ *---------------------------------------------------------*/
+
+long path_n_lt(PATH *p1, PATH *p2)
+{
+ return( (p1->npts < p2->npts ) );
+}
+
+long path_n_gt(PATH *p1, PATH *p2)
+{
+ return( (p1->npts > p2->npts ) );
+}
+
+long path_n_eq(PATH *p1, PATH *p2)
+{
+ return( (p1->npts == p2->npts) );
+}
+
+long path_n_le(PATH *p1, PATH *p2)
+{
+ return( (p1->npts <= p2->npts ) );
+}
+
+long path_n_ge(PATH *p1, PATH *p2)
+{
+ return( (p1->npts >= p2->npts ) );
+}
+
+/* path_inter -
+ * Does p1 intersect p2 at any point?
+ * Use bounding boxes for a quick (O(n)) check, then do a
+ * O(n^2) iterative edge check.
+ */
+long path_inter(PATH *p1, PATH *p2)
+{
+ BOX b1, b2;
+ int i, j;
+ LSEG seg1, seg2;
+
+ b1.xh = b1.yh = b2.xh = b2.yh = DBL_MAX;
+ b1.xl = b1.yl = b2.xl = b2.yl = -DBL_MAX;
+ for (i = 0; i < p1->npts; ++i) {
+ b1.xh = Max(p1->p[i].x, b1.xh);
+ b1.yh = Max(p1->p[i].y, b1.yh);
+ b1.xl = Min(p1->p[i].x, b1.xl);
+ b1.yl = Min(p1->p[i].y, b1.yl);
+ }
+ for (i = 0; i < p2->npts; ++i) {
+ b2.xh = Max(p2->p[i].x, b2.xh);
+ b2.yh = Max(p2->p[i].y, b2.yh);
+ b2.xl = Min(p2->p[i].x, b2.xl);
+ b2.yl = Min(p2->p[i].y, b2.yl);
+ }
+ if (! box_overlap(&b1, &b2))
+ return(0);
+
+ /* pairwise check lseg intersections */
+ for (i = 0; i < p1->npts - 1; i++) {
+ for (j = 0; j < p2->npts - 1; j++) {
+ statlseg_construct(&seg1, &p1->p[i], &p1->p[i+1]);
+ statlseg_construct(&seg2, &p2->p[j], &p2->p[j+1]);
+ if (lseg_intersect(&seg1, &seg2))
+ return(1);
+ }
+ }
+
+ /* if we dropped through, no two segs intersected */
+ return(0);
+}
+
+/* this essentially does a cartesian product of the lsegs in the
+ two paths, and finds the min distance between any two lsegs */
+double *path_distance(PATH *p1, PATH *p2)
+{
+ double *min, *tmp;
+ int i,j;
+ LSEG seg1, seg2;
+
+ statlseg_construct(&seg1, &p1->p[0], &p1->p[1]);
+ statlseg_construct(&seg2, &p2->p[0], &p2->p[1]);
+ min = lseg_distance(&seg1, &seg2);
+
+ for (i = 0; i < p1->npts - 1; i++)
+ for (j = 0; j < p2->npts - 1; j++)
+ {
+ statlseg_construct(&seg1, &p1->p[i], &p1->p[i+1]);
+ statlseg_construct(&seg2, &p2->p[j], &p2->p[j+1]);
+
+ if (*min < *(tmp = lseg_distance(&seg1, &seg2)))
+ *min = *tmp;
+ PFREE(tmp);
+ }
+
+ return(min);
+}
+
+
+/*----------------------------------------------------------
+ * "Arithmetic" operations.
+ *---------------------------------------------------------*/
+
+double *path_length(PATH *path)
+{
+ double *result;
+ int ct, i;
+
+ result = PALLOCTYPE(double);
+ ct = path->npts - 1;
+ for (i = 0; i < ct; ++i)
+ *result += point_dt(&path->p[i], &path->p[i+1]);
+
+ return(result);
+}
+
+
+
+double path_ln(PATH *path)
+{
+ double result;
+ int ct, i;
+
+ ct = path->npts - 1;
+ for (result = i = 0; i < ct; ++i)
+ result += point_dt(&path->p[i], &path->p[i+1]);
+
+ return(result);
+}
+/***********************************************************************
+ **
+ ** Routines for 2D points.
+ **
+ ***********************************************************************/
+
+/*----------------------------------------------------------
+ * String to point, point to string conversion.
+ * External form: "(x, y)"
+ *---------------------------------------------------------*/
+
+Point *point_in(char *str)
+{
+ char *coord[POINTNARGS], *p, *r;
+ int i;
+ Point *result;
+
+ if (str == NULL)
+ elog(WARN, "Bad (null) point external representation");
+
+ if ((p = (char *)strchr(str, LDELIM)) == (char *)NULL)
+ elog (WARN, "Bad point external representation '%s'",str);
+ for (i = 0, p++; *p && i < POINTNARGS-1 && *p != RDELIM; p = r+1)
+ if ((r = (char *)strchr(p, DELIM)) == (char *)NULL)
+ elog (WARN, "Bad point external representation '%s'",str);
+ else
+ coord[i++] = p;
+ if ((r = (char *)strchr(p, RDELIM)) == (char *)NULL)
+ elog (WARN, "Bad point external representation '%s'",str);
+ coord[i++] = p;
+
+ if (i < POINTNARGS - 1)
+ elog(WARN, "Bad point external representation '%s'",str);
+ result = PALLOCTYPE(Point);
+ result->x = atof(coord[0]);
+ result->y = atof(coord[1]);
+ return(result);
+}
+
+char *point_out(Point *pt)
+{
+ char *result;
+
+ if (pt == NULL)
+ return(NULL);
+ result = (char *)PALLOC(40);
+ (void) sprintf(result, "(%G,%G)", pt->x, pt->y);
+ return(result);
+}
+
+
+Point *point_construct(double x, double y)
+{
+ Point *result;
+
+ result = PALLOCTYPE(Point);
+ result->x = x;
+ result->y = y;
+ return(result);
+}
+
+
+Point *point_copy(Point *pt)
+{
+ Point *result;
+
+ result = PALLOCTYPE(Point);
+ result->x = pt->x;
+ result->y = pt->y;
+ return(result);
+}
+
+
+/*----------------------------------------------------------
+ * Relational operators for Points.
+ * Since we do have a sense of coordinates being
+ * "equal" to a given accuracy (point_vert, point_horiz),
+ * the other ops must preserve that sense. This means
+ * that results may, strictly speaking, be a lie (unless
+ * EPSILON = 0.0).
+ *---------------------------------------------------------*/
+
+long point_left(Point *pt1, Point *pt2)
+{
+ return( FPlt(pt1->x, pt2->x) );
+}
+
+long point_right(Point *pt1, Point *pt2)
+{
+ return( FPgt(pt1->x, pt2->x) );
+}
+
+long point_above(Point *pt1, Point *pt2)
+{
+ return( FPgt(pt1->y, pt2->y) );
+}
+
+long point_below(Point *pt1, Point *pt2)
+{
+ return( FPlt(pt1->y, pt2->y) );
+}
+
+long point_vert(Point *pt1, Point *pt2)
+{
+ return( FPeq( pt1->x, pt2->x ) );
+}
+
+long point_horiz(Point *pt1, Point *pt2)
+{
+ return( FPeq( pt1->y, pt2->y ) );
+}
+
+long point_eq(Point *pt1, Point *pt2)
+{
+ return( point_horiz(pt1, pt2) && point_vert(pt1, pt2) );
+}
+
+/*----------------------------------------------------------
+ * "Arithmetic" operators on points.
+ *---------------------------------------------------------*/
+
+long pointdist(Point *p1, Point *p2)
+{
+ long result;
+
+ result = point_dt(p1, p2);
+ return(result);
+}
+
+double *point_distance(Point *pt1, Point *pt2)
+{
+ double *result;
+
+ result = PALLOCTYPE(double);
+ *result = HYPOT( pt1->x - pt2->x, pt1->y - pt2->y );
+ return(result);
+}
+
+
+double point_dt(Point *pt1, Point *pt2)
+{
+ return( HYPOT( pt1->x - pt2->x, pt1->y - pt2->y ) );
+}
+
+double *point_slope(Point *pt1, Point *pt2)
+{
+ double *result;
+
+ result = PALLOCTYPE(double);
+ if (point_vert(pt1, pt2))
+ *result = DBL_MAX;
+ else
+ *result = (pt1->y - pt2->y) / (pt1->x - pt1->x);
+ return(result);
+}
+
+
+double point_sl(Point *pt1, Point *pt2)
+{
+ return( point_vert(pt1, pt2)
+ ? DBL_MAX
+ : (pt1->y - pt2->y) / (pt1->x - pt2->x) );
+}
+
+/***********************************************************************
+ **
+ ** Routines for 2D line segments.
+ **
+ ***********************************************************************/
+
+/*----------------------------------------------------------
+ * String to lseg, lseg to string conversion.
+ * External form: "(id, info, x1, y1, x2, y2)"
+ *---------------------------------------------------------*/
+
+LSEG *lseg_in(char *str)
+{
+ char *coord[LSEGNARGS], *p;
+ int i;
+ LSEG *result;
+
+ if (str == NULL)
+ elog (WARN," Bad (null) box external representation");
+
+ if ((p = (char *)strchr(str, LDELIM)) == (char *)NULL)
+ elog (WARN, "Bad lseg external representation '%s'",str);
+ for (i = 0, p = str; *p && i < LSEGNARGS && *p != RDELIM; p++)
+ if (*p == DELIM || (*p == LDELIM && !i))
+ coord[i++] = p + 1;
+ if (i < LSEGNARGS - 1)
+ elog (WARN, "Bad lseg external representation '%s'", str);
+ result = PALLOCTYPE(LSEG);
+ result->p[0].x = atof(coord[0]);
+ result->p[0].y = atof(coord[1]);
+ result->p[1].x = atof(coord[2]);
+ result->p[1].y = atof(coord[3]);
+ result->m = point_sl(&result->p[0], &result->p[1]);
+
+ return(result);
+}
+
+
+char *lseg_out(LSEG *ls)
+{
+ char *result;
+
+ if (ls == NULL)
+ return(NULL);
+ result = (char *)PALLOC(80);
+ (void) sprintf(result, "(%G,%G,%G,%G)",
+ ls->p[0].x, ls->p[0].y, ls->p[1].x, ls->p[1].y);
+ return(result);
+}
+
+
+/* lseg_construct -
+ * form a LSEG from two Points.
+ */
+LSEG *lseg_construct(Point *pt1, Point *pt2)
+{
+ LSEG *result;
+
+ result = PALLOCTYPE(LSEG);
+ result->p[0].x = pt1->x;
+ result->p[0].y = pt1->y;
+ result->p[1].x = pt2->x;
+ result->p[1].y = pt2->y;
+ result->m = point_sl(pt1, pt2);
+
+ return(result);
+}
+
+/* like lseg_construct, but assume space already allocated */
+void statlseg_construct(LSEG *lseg, Point *pt1, Point *pt2)
+{
+ lseg->p[0].x = pt1->x;
+ lseg->p[0].y = pt1->y;
+ lseg->p[1].x = pt2->x;
+ lseg->p[1].y = pt2->y;
+ lseg->m = point_sl(pt1, pt2);
+}
+
+/*----------------------------------------------------------
+ * Relative position routines.
+ *---------------------------------------------------------*/
+
+/*
+ ** find intersection of the two lines, and see if it falls on
+ ** both segments.
+ */
+long lseg_intersect(LSEG *l1, LSEG *l2)
+{
+ LINE *ln;
+ Point *interpt;
+ long retval;
+
+ ln = line_construct_pp(&l2->p[0], &l2->p[1]);
+ interpt = interpt_sl(l1, ln);
+
+ if (interpt != NULL && on_ps(interpt, l2)) /* interpt on l1 and l2 */
+ retval = 1;
+ else retval = 0;
+ if (interpt != NULL) PFREE(interpt);
+ PFREE(ln);
+ return(retval);
+}
+
+long lseg_parallel(LSEG *l1, LSEG *l2)
+{
+ return( FPeq(l1->m, l2->m) );
+}
+
+long lseg_perp(LSEG *l1, LSEG *l2)
+{
+ if (! FPzero(l1->m))
+ return( FPeq(l2->m / l1->m, -1.0) );
+ else if (! FPzero(l2->m))
+ return( FPeq(l1->m / l2->m, -1.0) );
+ return(0); /* both 0.0 */
+}
+
+long lseg_vertical(LSEG *lseg)
+{
+ return( FPeq(lseg->p[0].x, lseg->p[1].x) );
+}
+
+long lseg_horizontal(LSEG *lseg)
+{
+ return( FPeq(lseg->p[0].y, lseg->p[1].y) );
+}
+
+
+long lseg_eq(LSEG *l1, LSEG *l2)
+{
+ return( FPeq(l1->p[0].x, l2->p[0].x) &&
+ FPeq(l1->p[1].y, l2->p[1].y) &&
+ FPeq(l1->p[0].x, l2->p[0].x) &&
+ FPeq(l1->p[1].y, l2->p[1].y) );
+}
+
+
+/*----------------------------------------------------------
+ * Line arithmetic routines.
+ *---------------------------------------------------------*/
+
+/* lseg_distance -
+ * If two segments don't intersect, then the closest
+ * point will be from one of the endpoints to the other
+ * segment.
+ */
+double *lseg_distance(LSEG *l1, LSEG *l2)
+{
+ double *d, *result;
+
+ result = PALLOCTYPE(double);
+ if (lseg_intersect(l1, l2)) {
+ *result = 0.0;
+ return(result);
+ }
+ *result = DBL_MAX;
+ d = dist_ps(&l1->p[0], l2);
+ *result = Min(*result, *d);
+ PFREE(d);
+ d = dist_ps(&l1->p[1], l2);
+ *result = Min(*result, *d);
+ PFREE(d);
+ d = dist_ps(&l2->p[0], l1);
+ *result = Min(*result, *d);
+ PFREE(d);
+ d = dist_ps(&l2->p[1], l1);
+ *result = Min(*result, *d);
+ PFREE(d);
+
+ return(result);
+}
+
+/* distance between l1, l2 */
+double lseg_dt(LSEG *l1, LSEG *l2)
+{
+ double *d, result;
+
+ if (lseg_intersect(l1, l2))
+ return(0.0);
+ result = DBL_MAX;
+ d = dist_ps(&l1->p[0], l2);
+ result = Min(result, *d);
+ PFREE(d);
+ d = dist_ps(&l1->p[1], l2);
+ result = Min(result, *d);
+ PFREE(d);
+ d = dist_ps(&l2->p[0], l1);
+ result = Min(result, *d);
+ PFREE(d);
+ d = dist_ps(&l2->p[1], l1);
+ result = Min(result, *d);
+ PFREE(d);
+
+ return(result);
+}
+
+
+/* lseg_interpt -
+ * Find the intersection point of two segments (if any).
+ * Find the intersection of the appropriate lines; if the
+ * point is not on a given segment, there is no valid segment
+ * intersection point at all.
+ */
+Point *lseg_interpt(LSEG *l1, LSEG *l2)
+{
+ Point *result;
+ LINE *tmp1, *tmp2;
+
+ tmp1 = line_construct_pp(&l1->p[0], &l1->p[1]);
+ tmp2 = line_construct_pp(&l2->p[0], &l2->p[1]);
+ result = line_interpt(tmp1, tmp2);
+ if (result)
+ if (! on_ps(result, l1)) {
+ PFREE(result);
+ result = NULL;
+ }
+
+ PFREE(tmp1);
+ PFREE(tmp2);
+ return(result);
+}
+
+/***********************************************************************
+ **
+ ** Routines for position comparisons of differently-typed
+ ** 2D objects.
+ **
+ ***********************************************************************/
+
+#define ABOVE 1
+#define BELOW 0
+#define UNDEF -1
+
+
+/*---------------------------------------------------------------------
+ * dist_
+ * Minimum distance from one object to another.
+ *-------------------------------------------------------------------*/
+
+double *dist_pl(Point *pt, LINE *line)
+{
+ double *result;
+
+ result = PALLOCTYPE(double);
+ *result = (line->A * pt->x + line->B * pt->y + line->C) /
+ HYPOT(line->A, line->B);
+
+ return(result);
+}
+
+double *dist_ps(Point *pt, LSEG *lseg)
+{
+ double m; /* slope of perp. */
+ LINE *ln;
+ double *result, *tmpdist;
+ Point *ip;
+
+ /* construct a line that's perpendicular. See if the intersection of
+ the two lines is on the line segment. */
+ if (lseg->p[1].x == lseg->p[0].x)
+ m = 0;
+ else if (lseg->p[1].y == lseg->p[0].y) /* slope is infinite */
+ m = DBL_MAX;
+ else m = (-1) * (lseg->p[1].y - lseg->p[0].y) /
+ (lseg->p[1].x - lseg->p[0].x);
+ ln = line_construct_pm(pt, m);
+
+ if ((ip = interpt_sl(lseg, ln)) != NULL)
+ result = point_distance(pt, ip);
+ else /* intersection is not on line segment, so distance is min
+ of distance from point to an endpoint */
+ {
+ result = point_distance(pt, &lseg->p[0]);
+ tmpdist = point_distance(pt, &lseg->p[1]);
+ if (*tmpdist < *result) *result = *tmpdist;
+ PFREE (tmpdist);
+ }
+
+ if (ip != NULL) PFREE(ip);
+ PFREE(ln);
+ return (result);
+}
+
+
+/*
+ ** Distance from a point to a path
+ */
+double *dist_ppth(Point *pt, PATH *path)
+{
+ double *result;
+ double *tmp;
+ int i;
+ LSEG lseg;
+
+ switch (path->npts) {
+ case 0:
+ result = PALLOCTYPE(double);
+ *result = Abs((double) DBL_MAX); /* +infinity */
+ break;
+ case 1:
+ result = point_distance(pt, &path->p[0]);
+ break;
+ default:
+ /*
+ * the distance from a point to a path is the smallest distance
+ * from the point to any of its constituent segments.
+ */
+ Assert(path->npts > 1);
+ result = PALLOCTYPE(double);
+ for (i = 0; i < path->npts - 1; ++i) {
+ statlseg_construct(&lseg, &path->p[i], &path->p[i+1]);
+ tmp = dist_ps(pt, &lseg);
+ if (i == 0 || *tmp < *result)
+ *result = *tmp;
+ PFREE(tmp);
+ }
+ break;
+ }
+ return(result);
+}
+
+double *dist_pb(Point *pt, BOX *box)
+{
+ Point *tmp;
+ double *result;
+
+ tmp = close_pb(pt, box);
+ result = point_distance(tmp, pt);
+
+ PFREE(tmp);
+ return(result);
+}
+
+
+double *dist_sl(LSEG *lseg, LINE *line)
+{
+ double *result;
+
+ if (inter_sl(lseg, line)) {
+ result = PALLOCTYPE(double);
+ *result = 0.0;
+ } else /* parallel */
+ result = dist_pl(&lseg->p[0], line);
+
+ return(result);
+}
+
+
+double *dist_sb(LSEG *lseg, BOX *box)
+{
+ Point *tmp;
+ double *result;
+
+ tmp = close_sb(lseg, box);
+ if (tmp == NULL) {
+ result = PALLOCTYPE(double);
+ *result = 0.0;
+ } else {
+ result = dist_pb(tmp, box);
+ PFREE(tmp);
+ }
+
+ return(result);
+}
+
+
+double *dist_lb(LINE *line, BOX *box)
+{
+ Point *tmp;
+ double *result;
+
+ tmp = close_lb(line, box);
+ if (tmp == NULL) {
+ result = PALLOCTYPE(double);
+ *result = 0.0;
+ } else {
+ result = dist_pb(tmp, box);
+ PFREE(tmp);
+ }
+
+ return(result);
+}
+
+
+/*---------------------------------------------------------------------
+ * interpt_
+ * Intersection point of objects.
+ * We choose to ignore the "point" of intersection between
+ * lines and boxes, since there are typically two.
+ *-------------------------------------------------------------------*/
+
+Point *interpt_sl(LSEG *lseg, LINE *line)
+{
+ LINE *tmp;
+ Point *p;
+
+ tmp = line_construct_pp(&lseg->p[0], &lseg->p[1]);
+ p = line_interpt(tmp, line);
+ if (p)
+ if (! on_ps(p, lseg)) {
+ PFREE(p);
+ p = NULL;
+ }
+
+ PFREE(tmp);
+ return(p);
+}
+
+
+/*---------------------------------------------------------------------
+ * close_
+ * Point of closest proximity between objects.
+ *-------------------------------------------------------------------*/
+
+/* close_pl -
+ * The intersection point of a perpendicular of the line
+ * through the point.
+ */
+Point *close_pl(Point *pt, LINE *line)
+{
+ Point *result;
+ LINE *tmp;
+ double invm;
+
+ result = PALLOCTYPE(Point);
+ if (FPeq(line->A, -1.0) && FPzero(line->B)) { /* vertical */
+ result->x = line->C;
+ result->y = pt->y;
+ return(result);
+ } else if (FPzero(line->m)) { /* horizontal */
+ result->x = pt->x;
+ result->y = line->C;
+ return(result);
+ }
+ /* drop a perpendicular and find the intersection point */
+ invm = -1.0 / line->m;
+ tmp = line_construct_pm(pt, invm);
+ result = line_interpt(tmp, line);
+ return(result);
+}
+
+
+/* close_ps -
+ * Take the closest endpoint if the point is left, right,
+ * above, or below the segment, otherwise find the intersection
+ * point of the segment and its perpendicular through the point.
+ */
+Point *close_ps(Point *pt, LSEG *lseg)
+{
+ Point *result;
+ LINE *tmp;
+ double invm;
+ int xh, yh;
+
+ result = NULL;
+ xh = lseg->p[0].x < lseg->p[1].x;
+ yh = lseg->p[0].y < lseg->p[1].y;
+ if (pt->x < lseg->p[!xh].x)
+ result = point_copy(&lseg->p[!xh]);
+ else if (pt->x > lseg->p[xh].x)
+ result = point_copy(&lseg->p[xh]);
+ else if (pt->y < lseg->p[!yh].y)
+ result = point_copy(&lseg->p[!yh]);
+ else if (pt->y > lseg->p[yh].y)
+ result = point_copy(&lseg->p[yh]);
+ if (result)
+ return(result);
+ if (FPeq(lseg->p[0].x, lseg->p[1].x)) { /* vertical */
+ result->x = lseg->p[0].x;
+ result->y = pt->y;
+ return(result);
+ } else if (FPzero(lseg->m)) { /* horizontal */
+ result->x = pt->x;
+ result->y = lseg->p[0].y;
+ return(result);
+ }
+
+ invm = -1.0 / lseg->m;
+ tmp = line_construct_pm(pt, invm);
+ result = interpt_sl(lseg, tmp);
+ return(result);
+}
+
+Point *close_pb(Point *pt, BOX *box)
+{
+ /* think about this one for a while */
+
+ return(NULL);
+}
+
+Point *close_sl(LSEG *lseg, LINE *line)
+{
+ Point *result;
+ double *d1, *d2;
+
+ result = interpt_sl(lseg, line);
+ if (result)
+ return(result);
+ d1 = dist_pl(&lseg->p[0], line);
+ d2 = dist_pl(&lseg->p[1], line);
+ if (d1 < d2)
+ result = point_copy(&lseg->p[0]);
+ else
+ result = point_copy(&lseg->p[1]);
+
+ PFREE(d1);
+ PFREE(d2);
+ return(result);
+}
+
+Point *close_sb(LSEG *lseg, BOX *box)
+{
+ /* think about this one for a while */
+
+ return(NULL);
+}
+
+Point *close_lb(LINE *line, BOX *box)
+{
+ /* think about this one for a while */
+
+ return(NULL);
+}
+
+/*---------------------------------------------------------------------
+ * on_
+ * Whether one object lies completely within another.
+ *-------------------------------------------------------------------*/
+
+/* on_pl -
+ * Does the point satisfy the equation?
+ */
+long on_pl(Point *pt, LINE *line)
+{
+ return( FPzero(line->A * pt->x + line->B * pt->y + line->C) );
+}
+
+
+/* on_ps -
+ * Determine colinearity by detecting a triangle inequality.
+ */
+long on_ps(Point *pt, LSEG *lseg)
+{
+ return( point_dt(pt, &lseg->p[0]) + point_dt(pt, &lseg->p[1])
+ == point_dt(&lseg->p[0], &lseg->p[1]) );
+}
+
+long on_pb(Point *pt, BOX *box)
+{
+ return( pt->x <= box->xh && pt->x >= box->xl &&
+ pt->y <= box->yh && pt->y >= box->yl );
+}
+
+/* on_ppath -
+ * Whether a point lies within (on) a polyline.
+ * If open, we have to (groan) check each segment.
+ * If closed, we use the old O(n) ray method for point-in-polygon.
+ * The ray is horizontal, from pt out to the right.
+ * Each segment that crosses the ray counts as an
+ * intersection; note that an endpoint or edge may touch
+ * but not cross.
+ * (we can do p-in-p in lg(n), but it takes preprocessing)
+ */
+#define NEXT(A) ((A+1) % path->npts) /* cyclic "i+1" */
+
+long on_ppath(Point *pt, PATH *path)
+{
+ int above, next, /* is the seg above the ray? */
+ inter, /* # of times path crosses ray */
+ hi, /* index inc of higher seg (0,1) */
+ i, n;
+ double a, b, x,
+ yh, yl, xh, xl;
+
+ if (! path->closed) { /*-- OPEN --*/
+ n = path->npts - 1;
+ a = point_dt(pt, &path->p[0]);
+ for (i = 0; i < n; i++) {
+ b = point_dt(pt, &path->p[i+1]);
+ if (FPeq(a+b,
+ point_dt(&path->p[i], &path->p[i+1])))
+ return(1);
+ a = b;
+ }
+ return(0);
+ }
+
+ inter = 0; /*-- CLOSED --*/
+ above = FPgt(path->p[0].y, pt->y) ? ABOVE :
+ FPlt(path->p[0].y, pt->y) ? BELOW : UNDEF;
+
+ for (i = 0; i < path->npts; i++) {
+ hi = path->p[i].y < path->p[NEXT(i)].y;
+ /* must take care of wrap around to original vertex for closed paths */
+ yh = (i+hi < path->npts) ? path->p[i+hi].y : path->p[0].y;
+ yl = (i+!hi < path->npts) ? path->p[i+!hi].y : path->p[0].y;
+ hi = path->p[i].x < path->p[NEXT(i)].x;
+ xh = (i+hi < path->npts) ? path->p[i+hi].x : path->p[0].x;
+ xl = (i+!hi < path->npts) ? path->p[i+!hi].x : path->p[0].x;
+ /* skip seg if it doesn't touch the ray */
+
+ if (FPeq(yh, yl)) /* horizontal seg? */
+ if (FPge(pt->x, xl) && FPle(pt->x, xh) &&
+ FPeq(pt->y, yh))
+ return(1); /* pt lies on seg */
+ else
+ continue; /* skip other hz segs */
+ if (FPlt(yh, pt->y) || /* pt is strictly below seg */
+ FPgt(yl, pt->y)) /* strictly above */
+ continue;
+
+ /* seg touches the ray, find out where */
+
+ x = FPeq(xh, xl) /* vertical seg? */
+ ? path->p[i].x
+ : (pt->y - path->p[i].y) /
+ point_sl(&path->p[i],
+ &path->p[NEXT(i)]) +
+ path->p[i].x;
+ if (FPeq(x, pt->x)) /* pt lies on this seg */
+ return(1);
+
+ /* does the seg actually cross the ray? */
+
+ next = FPgt(path->p[NEXT(i)].y, pt->y) ? ABOVE :
+ FPlt(path->p[NEXT(i)].y, pt->y) ? BELOW : above;
+ inter += FPge(x, pt->x) && next != above;
+ above = next;
+ }
+ return( above == UNDEF || /* path is horizontal */
+ inter % 2); /* odd # of intersections */
+}
+
+
+long on_sl(LSEG *lseg, LINE *line)
+{
+ return( on_pl(&lseg->p[0], line) && on_pl(&lseg->p[1], line) );
+}
+
+long on_sb(LSEG *lseg, BOX *box)
+{
+ return( on_pb(&lseg->p[0], box) && on_pb(&lseg->p[1], box) );
+}
+
+/*---------------------------------------------------------------------
+ * inter_
+ * Whether one object intersects another.
+ *-------------------------------------------------------------------*/
+
+long inter_sl(LSEG *lseg, LINE *line)
+{
+ Point *tmp;
+
+ tmp = interpt_sl(lseg, line);
+ if (tmp) {
+ PFREE(tmp);
+ return(1);
+ }
+ return(0);
+}
+
+long inter_sb(LSEG *lseg, BOX *box)
+{
+ return(0);
+}
+
+long inter_lb(LINE *line, BOX *box)
+{
+ return(0);
+}
+
+/*------------------------------------------------------------------
+ * The following routines define a data type and operator class for
+ * POLYGONS .... Part of which (the polygon's bounding box is built on
+ * top of the BOX data type.
+ *
+ * make_bound_box - create the bounding box for the input polygon
+ *------------------------------------------------------------------*/
+
+/* Maximum number of output digits printed */
+#define P_MAXDIG 12
+
+/*---------------------------------------------------------------------
+ * Make the smallest bounding box for the given polygon.
+ *---------------------------------------------------------------------*/
+void make_bound_box(POLYGON *poly)
+{
+ double x1,y1,x2,y2;
+ int npts = poly->npts;
+
+ if (npts > 0) {
+ x1 = poly_min((double *)poly->pts, npts);
+ x2 = poly_max((double *)poly->pts, npts);
+ y1 = poly_min(((double *)poly->pts)+npts, npts),
+ y2 = poly_max(((double *)poly->pts)+npts, npts);
+ box_fill(&(poly->boundbox), x1, x2, y1, y2);
+ }
+}
+
+/*------------------------------------------------------------------
+ * polygon_in - read in the polygon from a string specification
+ * the string is of the form "(f8,f8,f8,f8,...,f8)"
+ *------------------------------------------------------------------*/
+POLYGON *poly_in(char *s)
+{
+ POLYGON *poly;
+ long points;
+ double *xp, *yp, strtod();
+ int i, size;
+
+ if((points = poly_pt_count(s, ',')) < 0)
+ elog(WARN, "Bad polygon external representation '%s'", s);
+
+ size = offsetof(POLYGON, pts[0]) + 2 * sizeof(double) * points;
+ poly = (POLYGON *) PALLOC(size);
+ memset((char *) poly, 0, size); /* zero any holes */
+
+ if (!PointerIsValid(poly))
+ elog(WARN, "Memory allocation failed, can't input polygon");
+
+ poly->npts = points;
+ poly->size = size;
+
+ /* Store all x coords followed by all y coords */
+ xp = (double *) &(poly->pts[0]);
+ yp = (double *) (poly->pts + points*sizeof(double));
+
+ s++; /* skip LDELIM */
+
+ for (i=0; i<points; i++,xp++,yp++)
+ {
+ *xp = strtod(s, &s);
+ s++; /* skip delimiter */
+ *yp = strtod(s, &s);
+ s++; /* skip delimiter */
+ }
+ make_bound_box(poly);
+ return (poly);
+}
+
+/*-------------------------------------------------------------
+ * poly_pt_count - count the number of points specified in the
+ * polygon.
+ *-------------------------------------------------------------*/
+long poly_pt_count(char *s, char delim)
+{
+ long total = 0;
+
+ if (*s++ != LDELIM) /* no left delimeter */
+ return (long) -1;
+
+ while (*s && (*s != RDELIM))
+ {
+ while (*s && (*s != delim))
+ s++;
+ total++; /* found one */
+ if (*s)
+ s++; /* bump s past the delimiter */
+ }
+
+ /* if there was no right delimiter OR an odd number of points */
+
+ if ((*(s-1) != RDELIM) || ((total%2) != 0))
+ return (long) -1;
+
+ return (total/2);
+}
+
+/*---------------------------------------------------------------
+ * poly_out - convert internal POLYGON representation to the
+ * character string format "(f8,f8,f8,f8,...f8)"
+ *---------------------------------------------------------------*/
+char *poly_out(POLYGON *poly)
+{
+ int i;
+ double *xp, *yp;
+ char *output, *outptr;
+
+ /*-----------------------------------------------------
+ * Get enough space for "(f8,f8,f8,f8,...,f8)"
+ * which P_MAXDIG+1 for each coordinate plus 2
+ * for parens and 1 for the null
+ *-----------------------------------------------------*/
+ output = (char *)PALLOC(2*(P_MAXDIG+1)*poly->npts + 3);
+ outptr = output;
+
+ if (!output)
+ elog(WARN, "Memory allocation failed, can't output polygon");
+
+ *outptr++ = LDELIM;
+
+ xp = (double *) poly->pts;
+ yp = (double *) (poly->pts + (poly->npts * sizeof(double)));
+
+ sprintf(outptr, "%*g,%*g", P_MAXDIG, *xp++, P_MAXDIG, *yp++);
+ outptr += (2*P_MAXDIG + 1);
+
+ for (i=1; i<poly->npts; i++,xp++,yp++)
+ {
+ sprintf(outptr, ",%*g,%*g", P_MAXDIG, *xp, P_MAXDIG, *yp);
+ outptr += 2*(P_MAXDIG + 1);
+ }
+ *outptr++ = RDELIM;
+ *outptr = '\0';
+ return (output);
+}
+
+/*-------------------------------------------------------
+ * Find the largest coordinate out of n coordinates
+ *-------------------------------------------------------*/
+double poly_max(double *coords, int ncoords)
+{
+ double max;
+
+ max = *coords++;
+ ncoords--;
+ while (ncoords--)
+ {
+ if (*coords > max)
+ max = *coords;
+ coords++;
+ }
+ return max;
+}
+
+/*-------------------------------------------------------
+ * Find the smallest coordinate out of n coordinates
+ *-------------------------------------------------------*/
+double poly_min(double *coords, int ncoords)
+{
+ double min;
+
+ min = *coords++;
+ ncoords--;
+ while (ncoords--)
+ {
+ if (*coords < min)
+ min = *coords;
+ coords++;
+ }
+ return min;
+}
+
+/*-------------------------------------------------------
+ * Is polygon A strictly left of polygon B? i.e. is
+ * the right most point of A left of the left most point
+ * of B?
+ *-------------------------------------------------------*/
+long poly_left(POLYGON *polya, POLYGON *polyb)
+{
+ double right, left;
+
+ if (polya->npts > 0)
+ right = poly_max((double *)polya->pts, polya->npts);
+ else
+ right = polya->boundbox.xh;
+ if (polyb->npts > 0)
+ left = poly_min((double *)polyb->pts, polyb->npts);
+ else
+ left = polyb->boundbox.xl;
+
+ return (right < left);
+}
+
+/*-------------------------------------------------------
+ * Is polygon A overlapping or left of polygon B? i.e. is
+ * the left most point of A left of the right most point
+ * of B?
+ *-------------------------------------------------------*/
+long poly_overleft(POLYGON *polya, POLYGON *polyb)
+{
+ double left, right;
+
+ if (polya->npts > 0)
+ left = poly_min((double *)polya->pts, polya->npts);
+ else
+ left = polya->boundbox.xl;
+ if (polyb->npts > 0)
+ right = poly_max((double *)polyb->pts, polyb->npts);
+ else
+ right = polyb->boundbox.xh;
+
+ return (left <= right);
+}
+
+/*-------------------------------------------------------
+ * Is polygon A strictly right of polygon B? i.e. is
+ * the left most point of A right of the right most point
+ * of B?
+ *-------------------------------------------------------*/
+long poly_right(POLYGON *polya, POLYGON *polyb)
+{
+ double right, left;
+
+ if (polya->npts > 0)
+ left = poly_min((double *)polya->pts, polya->npts);
+ else
+ left = polya->boundbox.xl;
+ if (polyb->npts > 0)
+ right = poly_max((double *)polyb->pts, polyb->npts);
+ else
+ right = polyb->boundbox.xh;
+
+ return (left > right);
+}
+
+/*-------------------------------------------------------
+ * Is polygon A overlapping or right of polygon B? i.e. is
+ * the right most point of A right of the left most point
+ * of B?
+ *-------------------------------------------------------*/
+long poly_overright(POLYGON *polya, POLYGON *polyb)
+{
+ double right, left;
+
+ if (polya->npts > 0)
+ right = poly_max((double *)polya->pts, polya->npts);
+ else
+ right = polya->boundbox.xh;
+ if (polyb->npts > 0)
+ left = poly_min((double *)polyb->pts, polyb->npts);
+ else
+ left = polyb->boundbox.xl;
+
+ return (right > left);
+}
+
+/*-------------------------------------------------------
+ * Is polygon A the same as polygon B? i.e. are all the
+ * points the same?
+ *-------------------------------------------------------*/
+long poly_same(POLYGON *polya, POLYGON *polyb)
+{
+ int i;
+ double *axp, *bxp; /* point to x coordinates for a and b */
+
+ if (polya->npts != polyb->npts)
+ return 0;
+
+ axp = (double *)polya->pts;
+ bxp = (double *)polyb->pts;
+
+ for (i=0; i<polya->npts; axp++, bxp++, i++)
+ {
+ if (*axp != *bxp)
+ return 0;
+ }
+ return 1;
+}
+
+/*-----------------------------------------------------------------
+ * Determine if polygon A overlaps polygon B by determining if
+ * their bounding boxes overlap.
+ *-----------------------------------------------------------------*/
+long poly_overlap(POLYGON *polya, POLYGON *polyb)
+{
+ return box_overlap(&(polya->boundbox), &(polyb->boundbox));
+}
+
+/*-----------------------------------------------------------------
+ * Determine if polygon A contains polygon B by determining if A's
+ * bounding box contains B's bounding box.
+ *-----------------------------------------------------------------*/
+long poly_contain(POLYGON *polya, POLYGON *polyb)
+{
+ return box_contain(&(polya->boundbox), &(polyb->boundbox));
+}
+
+/*-----------------------------------------------------------------
+ * Determine if polygon A is contained by polygon B by determining
+ * if A's bounding box is contained by B's bounding box.
+ *-----------------------------------------------------------------*/
+long poly_contained(POLYGON *polya, POLYGON *polyb)
+{
+ return box_contained(&(polya->boundbox), &(polyb->boundbox));
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-19 06:26:24 +0000