/**
* Returns the length of a circular arc segment
*/
double
lw_arc_length(const POINT2D *A1, const POINT2D *A2, const POINT2D *A3)
{
POINT2D C;
double radius_A, circumference_A;
int a2_side, clockwise;
double a1, a3;
double angle;
if ( lw_arc_is_pt(A1, A2, A3) )
return 0.0;
radius_A = lw_arc_center(A1, A2, A3, &C);
/* Co-linear! Return linear distance! */
if ( radius_A < 0 )
{
double dx = A1->x - A3->x;
double dy = A1->y - A3->y;
return sqrt(dx*dx + dy*dy);
}
/* Closed circle! Return the circumference! */
circumference_A = M_PI * 2 * radius_A;
if ( p2d_same(A1, A3) )
return circumference_A;
/* Determine the orientation of the arc */
a2_side = lw_segment_side(A1, A3, A2);
/* The side of the A1/A3 line that A2 falls on dictates the sweep
direction from A1 to A3. */
if ( a2_side == -1 )
clockwise = LW_TRUE;
else
clockwise = LW_FALSE;
/* Angles of each point that defines the arc section */
a1 = atan2(A1->y - C.y, A1->x - C.x);
a3 = atan2(A3->y - C.y, A3->x - C.x);
/* What's the sweep from A1 to A3? */
if ( clockwise )
{
if ( a1 > a3 )
angle = a1 - a3;
else
angle = 2*M_PI + a1 - a3;
}
else
{
if ( a3 > a1 )
angle = a3 - a1;
else
angle = 2*M_PI + a3 - a1;
}
/* Length as proportion of circumference */
return circumference_A * (angle / (2*M_PI));
}
/*
* Given a point, returns the location of closest point on pointarray
* and, optionally, it's actual distance from the point array.
*/
double
ptarray_locate_point(const POINTARRAY *pa, const POINT4D *p4d, double *mindistout, POINT4D *proj4d)
{
double mindist=-1;
double tlen, plen;
int t, seg=-1;
POINT4D start4d, end4d, projtmp;
POINT2D start, end, proj, p;
/* Initialize our 2D copy of the input parameter */
p.x = p4d->x;
p.y = p4d->y;
if ( ! proj4d ) proj4d = &projtmp;
getPoint2d_p(pa, 0, &start);
for (t=1; t<pa->npoints; t++)
{
double dist;
getPoint2d_p(pa, t, &end);
dist = distance2d_pt_seg(&p, &start, &end);
if (t==1 || dist < mindist )
{
mindist = dist;
seg=t-1;
}
if ( mindist == 0 )
{
LWDEBUG(3, "Breaking on mindist=0");
break;
}
start = end;
}
if ( mindistout ) *mindistout = mindist;
LWDEBUGF(3, "Closest segment: %d", seg);
LWDEBUGF(3, "mindist: %g", mindist);
/*
* We need to project the
* point on the closest segment.
*/
getPoint4d_p(pa, seg, &start4d);
getPoint4d_p(pa, seg+1, &end4d);
closest_point_on_segment(p4d, &start4d, &end4d, proj4d);
/* Copy 4D values into 2D holder */
proj.x = proj4d->x;
proj.y = proj4d->y;
LWDEBUGF(3, "Closest segment:%d, npoints:%d", seg, pa->npoints);
/* For robustness, force 1 when closest point == endpoint */
if ( (seg >= (pa->npoints-2)) && p2d_same(&proj, &end) )
{
return 1.0;
}
LWDEBUGF(3, "Closest point on segment: %g,%g", proj.x, proj.y);
tlen = ptarray_length_2d(pa);
LWDEBUGF(3, "tlen %g", tlen);
/* Location of any point on a zero-length line is 0 */
/* See http://trac.osgeo.org/postgis/ticket/1772#comment:2 */
if ( tlen == 0 ) return 0;
plen=0;
getPoint2d_p(pa, 0, &start);
for (t=0; t<seg; t++, start=end)
{
getPoint2d_p(pa, t+1, &end);
plen += distance2d_pt_pt(&start, &end);
LWDEBUGF(4, "Segment %d made plen %g", t, plen);
}
plen+=distance2d_pt_pt(&proj, &start);
LWDEBUGF(3, "plen %g, tlen %g", plen, tlen);
return plen/tlen;
}
int
ptarray_append_ptarray(POINTARRAY *pa1, POINTARRAY *pa2, double gap_tolerance)
{
unsigned int poff = 0;
unsigned int npoints;
unsigned int ncap;
unsigned int ptsize;
/* Check for pathology */
if( ! pa1 || ! pa2 )
{
lwerror("ptarray_append_ptarray: null input");
return LW_FAILURE;
}
npoints = pa2->npoints;
if ( ! npoints ) return LW_SUCCESS; /* nothing more to do */
if( FLAGS_GET_READONLY(pa1->flags) )
{
lwerror("ptarray_append_ptarray: target pointarray is read-only");
return LW_FAILURE;
}
if( FLAGS_GET_ZM(pa1->flags) != FLAGS_GET_ZM(pa2->flags) )
{
lwerror("ptarray_append_ptarray: appending mixed dimensionality is not allowed");
return LW_FAILURE;
}
ptsize = ptarray_point_size(pa1);
/* Check for duplicate end point */
if ( pa1->npoints )
{
POINT2D tmp1, tmp2;
getPoint2d_p(pa1, pa1->npoints-1, &tmp1);
getPoint2d_p(pa2, 0, &tmp2);
/* If the end point and start point are the same, then don't copy start point */
if (p2d_same(&tmp1, &tmp2)) {
poff = 1;
--npoints;
}
else if ( gap_tolerance == 0 || ( gap_tolerance > 0 &&
distance2d_pt_pt(&tmp1, &tmp2) > gap_tolerance ) )
{
lwerror("Second line start point too far from first line end point");
return LW_FAILURE;
}
}
/* Check if we need extra space */
ncap = pa1->npoints + npoints;
if ( pa1->maxpoints < ncap )
{
pa1->maxpoints = ncap > pa1->maxpoints*2 ?
ncap : pa1->maxpoints*2;
pa1->serialized_pointlist = (uint8_t *)lwrealloc(pa1->serialized_pointlist, ptsize * pa1->maxpoints);
}
memcpy(getPoint_internal(pa1, pa1->npoints),
getPoint_internal(pa2, poff), ptsize * npoints);
pa1->npoints = ncap;
return LW_SUCCESS;
}
int
ptarrayarc_contains_point_partial(const POINTARRAY *pa, const POINT2D *pt, int check_closed, int *winding_number)
{
int wn = 0;
int i, side;
const POINT2D *seg1;
const POINT2D *seg2;
const POINT2D *seg3;
GBOX gbox;
/* Check for not an arc ring (always have odd # of points) */
if ( (pa->npoints % 2) == 0 )
{
lwerror("ptarrayarc_contains_point called with even number of points");
return LW_OUTSIDE;
}
/* Check for not an arc ring (always have >= 3 points) */
if ( pa->npoints < 3 )
{
lwerror("ptarrayarc_contains_point called too-short pointarray");
return LW_OUTSIDE;
}
/* Check for unclosed case */
seg1 = getPoint2d_cp(pa, 0);
seg3 = getPoint2d_cp(pa, pa->npoints-1);
if ( check_closed && ! p2d_same(seg1, seg3) )
{
lwerror("ptarrayarc_contains_point called on unclosed ring");
return LW_OUTSIDE;
}
/* OK, it's closed. Is it just one circle? */
else if ( p2d_same(seg1, seg3) && pa->npoints == 3 )
{
double radius, d;
POINT2D c;
seg2 = getPoint2d_cp(pa, 1);
/* Wait, it's just a point, so it can't contain anything */
if ( lw_arc_is_pt(seg1, seg2, seg3) )
return LW_OUTSIDE;
/* See if the point is within the circle radius */
radius = lw_arc_center(seg1, seg2, seg3, &c);
d = distance2d_pt_pt(pt, &c);
if ( FP_EQUALS(d, radius) )
return LW_BOUNDARY; /* Boundary of circle */
else if ( d < radius )
return LW_INSIDE; /* Inside circle */
else
return LW_OUTSIDE; /* Outside circle */
}
else if ( p2d_same(seg1, pt) || p2d_same(seg3, pt) )
{
return LW_BOUNDARY; /* Boundary case */
}
/* Start on the ring */
seg1 = getPoint2d_cp(pa, 0);
for ( i=1; i < pa->npoints; i += 2 )
{
seg2 = getPoint2d_cp(pa, i);
seg3 = getPoint2d_cp(pa, i+1);
/* Catch an easy boundary case */
if( p2d_same(seg3, pt) )
return LW_BOUNDARY;
/* Skip arcs that have no size */
if ( lw_arc_is_pt(seg1, seg2, seg3) )
{
seg1 = seg3;
continue;
}
/* Only test segments in our vertical range */
lw_arc_calculate_gbox_cartesian_2d(seg1, seg2, seg3, &gbox);
if ( pt->y > gbox.ymax || pt->y < gbox.ymin )
{
seg1 = seg3;
continue;
}
/* Outside of horizontal range, and not between end points we also skip */
if ( (pt->x > gbox.xmax || pt->x < gbox.xmin) &&
(pt->y > FP_MAX(seg1->y, seg3->y) || pt->y < FP_MIN(seg1->y, seg3->y)) )
{
seg1 = seg3;
continue;
}
side = lw_arc_side(seg1, seg2, seg3, pt);
/* On the boundary */
if ( (side == 0) && lw_pt_in_arc(pt, seg1, seg2, seg3) )
{
return LW_BOUNDARY;
}
/* Going "up"! Point to left of arc. */
if ( side < 0 && (seg1->y <= pt->y) && (pt->y < seg3->y) )
{
wn++;
}
/* Going "down"! */
if ( side > 0 && (seg2->y <= pt->y) && (pt->y < seg1->y) )
{
wn--;
}
/* Inside the arc! */
if ( pt->x <= gbox.xmax && pt->x >= gbox.xmin )
{
POINT2D C;
double radius = lw_arc_center(seg1, seg2, seg3, &C);
double d = distance2d_pt_pt(pt, &C);
/* On the boundary! */
if ( d == radius )
return LW_BOUNDARY;
/* Within the arc! */
if ( d < radius )
{
/* Left side, increment winding number */
if ( side < 0 )
wn++;
/* Right side, decrement winding number */
if ( side > 0 )
wn--;
}
}
seg1 = seg3;
}
/* Sent out the winding number for calls that are building on this as a primitive */
if ( winding_number )
*winding_number = wn;
/* Outside */
if (wn == 0)
{
return LW_OUTSIDE;
}
/* Inside */
return LW_INSIDE;
}
int
ptarray_contains_point_partial(const POINTARRAY *pa, const POINT2D *pt, int check_closed, int *winding_number)
{
int wn = 0;
int i;
double side;
const POINT2D *seg1;
const POINT2D *seg2;
double ymin, ymax;
seg1 = getPoint2d_cp(pa, 0);
seg2 = getPoint2d_cp(pa, pa->npoints-1);
if ( check_closed && ! p2d_same(seg1, seg2) )
lwerror("ptarray_contains_point called on unclosed ring");
for ( i=1; i < pa->npoints; i++ )
{
seg2 = getPoint2d_cp(pa, i);
/* Zero length segments are ignored. */
if ( seg1->x == seg2->x && seg1->y == seg2->y )
{
seg1 = seg2;
continue;
}
ymin = FP_MIN(seg1->y, seg2->y);
ymax = FP_MAX(seg1->y, seg2->y);
/* Only test segments in our vertical range */
if ( pt->y > ymax || pt->y < ymin )
{
seg1 = seg2;
continue;
}
side = lw_segment_side(seg1, seg2, pt);
/*
* A point on the boundary of a ring is not contained.
* WAS: if (fabs(side) < 1e-12), see #852
*/
if ( (side == 0) && lw_pt_in_seg(pt, seg1, seg2) )
{
return LW_BOUNDARY;
}
/*
* If the point is to the left of the line, and it's rising,
* then the line is to the right of the point and
* circling counter-clockwise, so incremement.
*/
if ( (side < 0) && (seg1->y <= pt->y) && (pt->y < seg2->y) )
{
wn++;
}
/*
* If the point is to the right of the line, and it's falling,
* then the line is to the right of the point and circling
* clockwise, so decrement.
*/
else if ( (side > 0) && (seg2->y <= pt->y) && (pt->y < seg1->y) )
{
wn--;
}
seg1 = seg2;
}
/* Sent out the winding number for calls that are building on this as a primitive */
if ( winding_number )
*winding_number = wn;
/* Outside */
if (wn == 0)
{
return LW_OUTSIDE;
}
/* Inside */
return LW_INSIDE;
}
