*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.31 1998/02/26 04:37:08 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.32 1998/05/09 22:39:55 thomas Exp $
*
*-------------------------------------------------------------------------
*/
static double circle_ar(CIRCLE *circle);
static CIRCLE *circle_copy(CIRCLE *circle);
static LINE *line_construct_pm(Point *pt, double m);
-static bool line_horizontal(LINE *line);
-static Point *line_interpt(LINE *l1, LINE *l2);
-static bool line_intersect(LINE *l1, LINE *l2);
-static bool line_parallel(LINE *l1, LINE *l2);
-static bool line_vertical(LINE *line);
static double lseg_dt(LSEG *l1, LSEG *l2);
static void make_bound_box(POLYGON *poly);
static PATH *path_copy(PATH *path);
static void statlseg_construct(LSEG *lseg, Point *pt1, Point *pt2);
static double box_ar(BOX *box);
static Point *interpt_sl(LSEG *lseg, LINE *line);
-static LINE *line_construct_pp(Point *pt1, Point *pt2);
/*
**
***********************************************************************/
+LINE *
+line_in(char *str)
+{
+ LINE *line;
+
+#if LINEDEBUG
+ LSEG lseg;
+ int isopen;
+ char *s;
+#endif
+
+ if (!PointerIsValid(str))
+ elog(ERROR, " Bad (null) line external representation", NULL);
+
+#if LINEDEBUG
+ if ((!path_decode(TRUE, 2, str, &isopen, &s, &(lseg.p[0])))
+ || (*s != '\0'))
+ elog(ERROR, "Bad line external representation '%s'", str);
+
+ line = line_construct_pp(&(lseg.p[0]), &(lseg.p[1]));
+#else
+ elog(ERROR, "line not yet implemented");
+ line = NULL;
+#endif
+
+ return (line);
+} /* line_in() */
+
+
+char *
+line_out(LINE *line)
+{
+ char *result;
+
+ if (!PointerIsValid(line))
+ return (NULL);
+
+#if LINEDEBUG
+ if (FPzero(line->B))
+ { /* vertical */
+ /* use "x = C" */
+ result->A = -1;
+ result->B = 0;
+ result->C = pt1->x;
+#ifdef GEODEBUG
+ printf("line_construct_pp- line is vertical\n");
+#endif
+#if FALSE
+ result->m = DBL_MAX;
+#endif
+
+ }
+ else if (FPzero(line->A))
+ { /* horizontal */
+ /* use "x = C" */
+ result->A = 0;
+ result->B = -1;
+ result->C = pt1->y;
+#ifdef GEODEBUG
+ printf("line_construct_pp- line is horizontal\n");
+#endif
+#if FALSE
+ result->m = 0.0;
+#endif
+
+ }
+ else
+ {
+ }
+
+ if (line_horizontal(line))
+ {
+ }
+ else if (line_vertical(line))
+ {
+ }
+ else
+ {
+ }
+
+ return (path_encode(TRUE, 2, (Point *) &(ls->p[0])));
+#else
+ elog(ERROR, "line not yet implemented");
+ result = NULL;
+#endif
+
+ return (result);
+} /* line_out() */
+
+
/*----------------------------------------------------------
* Conversion routines from one line formula to internal.
* Internal form: Ax+By+C=0
*---------------------------------------------------------*/
-static LINE * /* point-slope */
+/* line_construct_pm()
+ * point-slope
+ */
+LINE *
line_construct_pm(Point *pt, double m)
{
LINE *result = palloc(sizeof(LINE));
} /* line_construct_pm() */
-static LINE * /* two points */
+/* line_construct_pp()
+ * two points
+ */
+LINE *
line_construct_pp(Point *pt1, Point *pt2)
{
LINE *result = palloc(sizeof(LINE));
* Relative position routines.
*---------------------------------------------------------*/
-static bool
+bool
line_intersect(LINE *l1, LINE *l2)
{
return (!line_parallel(l1, l2));
}
-static bool
+bool
line_parallel(LINE *l1, LINE *l2)
{
#if FALSE
return (FPeq(l2->A, l1->A * (l2->B / l1->B)));
} /* line_parallel() */
-#ifdef NOT_USED
bool
line_perp(LINE *l1, LINE *l2)
{
return (FPeq(((l1->A * l2->B) / (l1->B * l2->A)), -1.0));
} /* line_perp() */
-#endif
-
-static bool
+bool
line_vertical(LINE *line)
{
#if FALSE
return (FPzero(line->B));
} /* line_vertical() */
-static bool
+bool
line_horizontal(LINE *line)
{
#if FALSE
return (FPzero(line->A));
} /* line_horizontal() */
-#ifdef NOT_USED
bool
line_eq(LINE *l1, LINE *l2)
{
FPeq(l1->C, k * l2->C));
}
-#endif
/*----------------------------------------------------------
* Line arithmetic routines.
*---------------------------------------------------------*/
-double * /* distance between l1, l2 */
+/* line_distance()
+ * Distance between two lines.
+ */
+double *
line_distance(LINE *l1, LINE *l2)
{
double *result = palloc(sizeof(double));
/* line_interpt()
* Point where two lines l1, l2 intersect (if any)
*/
-static Point *
+Point *
line_interpt(LINE *l1, LINE *l2)
{
Point *result;
*
* Some tricky code here, relying on boolean expressions
* evaluating to only zero or one to use as an array index.
*/
Point *
close_ps(Point *pt, LSEG *lseg)
int xh,
yh;
+
+/* 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", */
+/* pt->x, pt->y, lseg->p[0].x, lseg->p[0].y, lseg->p[1].x, lseg->p[1].y); */
+
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 != NULL)
- return (result);
+ /* !xh (or !yh) is the index of lower x( or y) end point of lseg */
/* vertical segment? */
if (lseg_vertical(lseg))
#ifdef GEODEBUG
printf("close_ps- segment is vertical\n");
#endif
+ /* first check if point is below or above the entire lseg. */
+ if (pt->y < lseg->p[!yh].y)
+ result = point_copy(&lseg->p[!yh]); /* below the lseg */
+ else if (pt->y > lseg->p[yh].y)
+ result = point_copy(&lseg->p[yh]); /* above the lseg */
+ if (result != NULL)
+ return (result);
+
+ /* point lines along (to left or right) of the vertical lseg. */
+
result = palloc(sizeof(*result));
result->x = lseg->p[0].x;
result->y = pt->y;
#ifdef GEODEBUG
printf("close_ps- segment is horizontal\n");
#endif
+ /* first check if point is left or right of the entire lseg. */
+ if (pt->x < lseg->p[!xh].x)
+ result = point_copy(&lseg->p[!xh]); /* left of the lseg */
+ else if (pt->x > lseg->p[xh].x)
+ result = point_copy(&lseg->p[xh]); /* right of the lseg */
+ if (result != NULL)
+ return (result);
+
+ /* point lines along (at top or below) the horiz. lseg. */
result = palloc(sizeof(*result));
result->x = pt->x;
result->y = lseg->p[0].y;
return (result);
}
+ /* vert. and horiz. cases are down, now check if the closest
+ * point is one of the end points or someplace on the lseg. */
+
+ /* TODO: Ask if "tmp" should be freed to prevent memory leak */
+
invm = -1.0 / point_sl(&(lseg->p[0]), &(lseg->p[1]));
+ tmp = line_construct_pm(&lseg->p[!yh], invm); /* lower edge of the "band" */
+ if (pt->y < (tmp->A*pt->x + tmp->C)) { /* we are below the lower edge */
+ result = point_copy(&lseg->p[!yh]); /* below the lseg, take lower end pt */
+/* fprintf(stderr,"below: tmp A %f B %f C %f m %f\n",tmp->A,tmp->B,tmp->C, tmp->m); */
+
+ return result;
+ }
+ tmp = line_construct_pm(&lseg->p[yh], invm); /* upper edge of the "band" */
+ if (pt->y > (tmp->A*pt->x + tmp->C)) { /* we are below the lower edge */
+ result = point_copy(&lseg->p[yh]); /* above the lseg, take higher end pt */
+/* fprintf(stderr,"above: tmp A %f B %f C %f m %f\n",tmp->A,tmp->B,tmp->C, tmp->m); */
+ return result;
+ }
+
+ /* at this point the "normal" from point will hit lseg. The closet point
+ * will be somewhere on the lseg */
tmp = line_construct_pm(pt, invm);
+/* fprintf(stderr,"tmp A %f B %f C %f m %f\n",tmp->A,tmp->B,tmp->C, tmp->m); */
result = interpt_sl(lseg, tmp);
+/* fprintf(stderr,"result.x %f result.y %f\n", result->x, result->y); */
return (result);
} /* close_ps() */
} /* box_div() */
-/***********************************************************************
- **
- ** 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.
- **
- ***********************************************************************/
-
-
/***********************************************************************
**
** Routines for 2D paths.
} /* box_circle() */
-POLYGON *
+POLYGON *
circle_poly(int npts, CIRCLE *circle)
{
POLYGON *poly;
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