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Make a few line routines visible.
Incorporate patches from Gautam for line/point intersection.
This commit is contained in:
Thomas G. Lockhart
parent
8e602a3cb7
commit
70c4c57e42
@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.31 1998/02/26 04:37:08 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.32 1998/05/09 22:39:55 thomas Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -42,11 +42,6 @@ static double box_wd(BOX *box);
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static double circle_ar(CIRCLE *circle);
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static CIRCLE *circle_copy(CIRCLE *circle);
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static LINE *line_construct_pm(Point *pt, double m);
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static bool line_horizontal(LINE *line);
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static Point *line_interpt(LINE *l1, LINE *l2);
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static bool line_intersect(LINE *l1, LINE *l2);
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static bool line_parallel(LINE *l1, LINE *l2);
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static bool line_vertical(LINE *line);
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static double lseg_dt(LSEG *l1, LSEG *l2);
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static void make_bound_box(POLYGON *poly);
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static PATH *path_copy(PATH *path);
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@ -63,7 +58,6 @@ static char *path_encode(bool closed, int npts, Point *pt);
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static void statlseg_construct(LSEG *lseg, Point *pt1, Point *pt2);
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static double box_ar(BOX *box);
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static Point *interpt_sl(LSEG *lseg, LINE *line);
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static LINE *line_construct_pp(Point *pt1, Point *pt2);
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/*
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@ -776,12 +770,105 @@ box_diagonal(BOX *box)
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**
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***********************************************************************/
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LINE *
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line_in(char *str)
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{
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LINE *line;
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#if LINEDEBUG
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LSEG lseg;
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int isopen;
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char *s;
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#endif
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if (!PointerIsValid(str))
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elog(ERROR, " Bad (null) line external representation", NULL);
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#if LINEDEBUG
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if ((!path_decode(TRUE, 2, str, &isopen, &s, &(lseg.p[0])))
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|| (*s != '\0'))
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elog(ERROR, "Bad line external representation '%s'", str);
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line = line_construct_pp(&(lseg.p[0]), &(lseg.p[1]));
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#else
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elog(ERROR, "line not yet implemented");
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line = NULL;
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#endif
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return (line);
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} /* line_in() */
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char *
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line_out(LINE *line)
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{
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char *result;
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if (!PointerIsValid(line))
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return (NULL);
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#if LINEDEBUG
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if (FPzero(line->B))
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{ /* vertical */
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/* use "x = C" */
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result->A = -1;
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result->B = 0;
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result->C = pt1->x;
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#ifdef GEODEBUG
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printf("line_construct_pp- line is vertical\n");
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#endif
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#if FALSE
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result->m = DBL_MAX;
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#endif
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}
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else if (FPzero(line->A))
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{ /* horizontal */
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/* use "x = C" */
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result->A = 0;
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result->B = -1;
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result->C = pt1->y;
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#ifdef GEODEBUG
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printf("line_construct_pp- line is horizontal\n");
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#endif
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#if FALSE
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result->m = 0.0;
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#endif
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}
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else
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{
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}
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if (line_horizontal(line))
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{
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}
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else if (line_vertical(line))
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{
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}
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else
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{
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}
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return (path_encode(TRUE, 2, (Point *) &(ls->p[0])));
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#else
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elog(ERROR, "line not yet implemented");
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result = NULL;
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#endif
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return (result);
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} /* line_out() */
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/*----------------------------------------------------------
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* Conversion routines from one line formula to internal.
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* Internal form: Ax+By+C=0
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*---------------------------------------------------------*/
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static LINE * /* point-slope */
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/* line_construct_pm()
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* point-slope
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*/
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LINE *
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line_construct_pm(Point *pt, double m)
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{
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LINE *result = palloc(sizeof(LINE));
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@ -799,7 +886,10 @@ line_construct_pm(Point *pt, double m)
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} /* line_construct_pm() */
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static LINE * /* two points */
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/* line_construct_pp()
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* two points
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*/
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LINE *
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line_construct_pp(Point *pt1, Point *pt2)
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{
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LINE *result = palloc(sizeof(LINE));
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@ -857,13 +947,13 @@ line_construct_pp(Point *pt1, Point *pt2)
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* Relative position routines.
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*---------------------------------------------------------*/
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static bool
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bool
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line_intersect(LINE *l1, LINE *l2)
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{
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return (!line_parallel(l1, l2));
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}
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static bool
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bool
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line_parallel(LINE *l1, LINE *l2)
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{
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#if FALSE
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@ -877,7 +967,6 @@ line_parallel(LINE *l1, LINE *l2)
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return (FPeq(l2->A, l1->A * (l2->B / l1->B)));
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} /* line_parallel() */
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#ifdef NOT_USED
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bool
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line_perp(LINE *l1, LINE *l2)
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{
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@ -899,9 +988,7 @@ line_perp(LINE *l1, LINE *l2)
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return (FPeq(((l1->A * l2->B) / (l1->B * l2->A)), -1.0));
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} /* line_perp() */
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#endif
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static bool
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bool
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line_vertical(LINE *line)
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{
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#if FALSE
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@ -910,7 +997,7 @@ line_vertical(LINE *line)
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return (FPzero(line->B));
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} /* line_vertical() */
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static bool
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bool
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line_horizontal(LINE *line)
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{
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#if FALSE
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@ -919,7 +1006,6 @@ line_horizontal(LINE *line)
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return (FPzero(line->A));
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} /* line_horizontal() */
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#ifdef NOT_USED
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bool
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line_eq(LINE *l1, LINE *l2)
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{
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@ -939,13 +1025,15 @@ line_eq(LINE *l1, LINE *l2)
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FPeq(l1->C, k * l2->C));
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}
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#endif
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/*----------------------------------------------------------
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* Line arithmetic routines.
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*---------------------------------------------------------*/
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double * /* distance between l1, l2 */
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/* line_distance()
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* Distance between two lines.
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*/
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double *
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line_distance(LINE *l1, LINE *l2)
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{
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double *result = palloc(sizeof(double));
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@ -970,7 +1058,7 @@ line_distance(LINE *l1, LINE *l2)
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/* line_interpt()
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* Point where two lines l1, l2 intersect (if any)
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*/
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static Point *
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Point *
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line_interpt(LINE *l1, LINE *l2)
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{
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Point *result;
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@ -2266,6 +2354,7 @@ close_pl(Point *pt, LINE *line)
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*
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* Some tricky code here, relying on boolean expressions
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* evaluating to only zero or one to use as an array index.
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* bug fixes by gthaker@atl.lmco.com; May 1, 98
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*/
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Point *
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close_ps(Point *pt, LSEG *lseg)
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@ -2276,19 +2365,14 @@ close_ps(Point *pt, LSEG *lseg)
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int xh,
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yh;
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/* fprintf(stderr,"close_sp:pt->x %f pt->y %f\nlseg(0).x %f lseg(0).y %f lseg(1).x %f lseg(1).y %f\n", */
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/* pt->x, pt->y, lseg->p[0].x, lseg->p[0].y, lseg->p[1].x, lseg->p[1].y); */
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result = NULL;
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xh = lseg->p[0].x < lseg->p[1].x;
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yh = lseg->p[0].y < lseg->p[1].y;
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if (pt->x < lseg->p[!xh].x)
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result = point_copy(&lseg->p[!xh]);
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else if (pt->x > lseg->p[xh].x)
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result = point_copy(&lseg->p[xh]);
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else if (pt->y < lseg->p[!yh].y)
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result = point_copy(&lseg->p[!yh]);
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else if (pt->y > lseg->p[yh].y)
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result = point_copy(&lseg->p[yh]);
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if (result != NULL)
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return (result);
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/* !xh (or !yh) is the index of lower x( or y) end point of lseg */
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/* vertical segment? */
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if (lseg_vertical(lseg))
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@ -2296,6 +2380,16 @@ close_ps(Point *pt, LSEG *lseg)
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#ifdef GEODEBUG
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printf("close_ps- segment is vertical\n");
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#endif
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/* first check if point is below or above the entire lseg. */
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if (pt->y < lseg->p[!yh].y)
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result = point_copy(&lseg->p[!yh]); /* below the lseg */
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else if (pt->y > lseg->p[yh].y)
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result = point_copy(&lseg->p[yh]); /* above the lseg */
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if (result != NULL)
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return (result);
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/* point lines along (to left or right) of the vertical lseg. */
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result = palloc(sizeof(*result));
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result->x = lseg->p[0].x;
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result->y = pt->y;
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@ -2306,15 +2400,47 @@ close_ps(Point *pt, LSEG *lseg)
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#ifdef GEODEBUG
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printf("close_ps- segment is horizontal\n");
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#endif
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/* first check if point is left or right of the entire lseg. */
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if (pt->x < lseg->p[!xh].x)
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result = point_copy(&lseg->p[!xh]); /* left of the lseg */
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else if (pt->x > lseg->p[xh].x)
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result = point_copy(&lseg->p[xh]); /* right of the lseg */
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if (result != NULL)
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return (result);
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/* point lines along (at top or below) the horiz. lseg. */
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result = palloc(sizeof(*result));
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result->x = pt->x;
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result->y = lseg->p[0].y;
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return (result);
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}
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/* vert. and horiz. cases are down, now check if the closest
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* point is one of the end points or someplace on the lseg. */
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/* TODO: Ask if "tmp" should be freed to prevent memory leak */
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invm = -1.0 / point_sl(&(lseg->p[0]), &(lseg->p[1]));
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tmp = line_construct_pm(&lseg->p[!yh], invm); /* lower edge of the "band" */
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if (pt->y < (tmp->A*pt->x + tmp->C)) { /* we are below the lower edge */
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result = point_copy(&lseg->p[!yh]); /* below the lseg, take lower end pt */
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/* fprintf(stderr,"below: tmp A %f B %f C %f m %f\n",tmp->A,tmp->B,tmp->C, tmp->m); */
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return result;
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}
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tmp = line_construct_pm(&lseg->p[yh], invm); /* upper edge of the "band" */
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if (pt->y > (tmp->A*pt->x + tmp->C)) { /* we are below the lower edge */
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result = point_copy(&lseg->p[yh]); /* above the lseg, take higher end pt */
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/* fprintf(stderr,"above: tmp A %f B %f C %f m %f\n",tmp->A,tmp->B,tmp->C, tmp->m); */
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return result;
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}
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/* at this point the "normal" from point will hit lseg. The closet point
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* will be somewhere on the lseg */
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tmp = line_construct_pm(pt, invm);
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/* fprintf(stderr,"tmp A %f B %f C %f m %f\n",tmp->A,tmp->B,tmp->C, tmp->m); */
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result = interpt_sl(lseg, tmp);
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/* fprintf(stderr,"result.x %f result.y %f\n", result->x, result->y); */
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return (result);
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} /* close_ps() */
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@ -3309,16 +3435,6 @@ box_div(BOX *box, Point *p)
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} /* box_div() */
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/***********************************************************************
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**
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** Routines for 2D lines.
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** Lines are not intended to be used as ADTs per se,
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** but their ops are useful tools for other ADT ops. Thus,
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** there are few relops.
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**
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***********************************************************************/
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/***********************************************************************
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**
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** Routines for 2D paths.
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