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postgis/liblwgeom/ptarray.c

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/**********************************************************************
*
* PostGIS - Spatial Types for PostgreSQL
* http://postgis.net
*
* PostGIS is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* PostGIS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with PostGIS. If not, see <http://www.gnu.org/licenses/>.
*
**********************************************************************
*
* Copyright (C) 2012-2021 Sandro Santilli <strk@kbt.io>
* Copyright (C) 2001-2006 Refractions Research Inc.
*
**********************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "../postgis_config.h"
/*#define POSTGIS_DEBUG_LEVEL 4*/
#include "liblwgeom_internal.h"
#include "lwgeom_log.h"
int
ptarray_has_z(const POINTARRAY *pa)
{
if ( ! pa ) return LW_FALSE;
return FLAGS_GET_Z(pa->flags);
}
int
ptarray_has_m(const POINTARRAY *pa)
{
if ( ! pa ) return LW_FALSE;
return FLAGS_GET_M(pa->flags);
}
POINTARRAY*
ptarray_construct(char hasz, char hasm, uint32_t npoints)
{
POINTARRAY *pa = ptarray_construct_empty(hasz, hasm, npoints);
pa->npoints = npoints;
return pa;
}
POINTARRAY*
ptarray_construct_empty(char hasz, char hasm, uint32_t maxpoints)
{
POINTARRAY *pa = lwalloc(sizeof(POINTARRAY));
pa->serialized_pointlist = NULL;
/* Set our dimensionality info on the bitmap */
pa->flags = lwflags(hasz, hasm, 0);
/* We will be allocating a bit of room */
pa->npoints = 0;
pa->maxpoints = maxpoints;
/* Allocate the coordinate array */
if ( maxpoints > 0 )
pa->serialized_pointlist = lwalloc(maxpoints * ptarray_point_size(pa));
else
pa->serialized_pointlist = NULL;
return pa;
}
/*
* Add a point into a pointarray. Only adds as many dimensions as the
* pointarray supports.
*/
int
ptarray_insert_point(POINTARRAY *pa, const POINT4D *p, uint32_t where)
{
if (!pa || !p)
return LW_FAILURE;
size_t point_size = ptarray_point_size(pa);
LWDEBUGF(5,"pa = %p; p = %p; where = %d", pa, p, where);
LWDEBUGF(5,"pa->npoints = %d; pa->maxpoints = %d", pa->npoints, pa->maxpoints);
if ( FLAGS_GET_READONLY(pa->flags) )
{
lwerror("ptarray_insert_point: called on read-only point array");
return LW_FAILURE;
}
/* Error on invalid offset value */
if ( where > pa->npoints )
{
lwerror("ptarray_insert_point: offset out of range (%d)", where);
return LW_FAILURE;
}
/* If we have no storage, let's allocate some */
if( pa->maxpoints == 0 || ! pa->serialized_pointlist )
{
pa->maxpoints = 32;
pa->npoints = 0;
pa->serialized_pointlist = lwalloc(ptarray_point_size(pa) * pa->maxpoints);
}
/* Error out if we have a bad situation */
if ( pa->npoints > pa->maxpoints )
{
lwerror("npoints (%d) is greater than maxpoints (%d)", pa->npoints, pa->maxpoints);
return LW_FAILURE;
}
/* Check if we have enough storage, add more if necessary */
if( pa->npoints == pa->maxpoints )
{
pa->maxpoints *= 2;
pa->serialized_pointlist = lwrealloc(pa->serialized_pointlist, ptarray_point_size(pa) * pa->maxpoints);
}
/* Make space to insert the new point */
if( where < pa->npoints )
{
size_t copy_size = point_size * (pa->npoints - where);
memmove(getPoint_internal(pa, where+1), getPoint_internal(pa, where), copy_size);
LWDEBUGF(5,"copying %d bytes to start vertex %d from start vertex %d", copy_size, where+1, where);
}
/* We have one more point */
++pa->npoints;
/* Copy the new point into the gap */
ptarray_set_point4d(pa, where, p);
LWDEBUGF(5,"copying new point to start vertex %d", point_size, where);
return LW_SUCCESS;
}
int
ptarray_append_point(POINTARRAY *pa, const POINT4D *pt, int repeated_points)
{
/* Check for pathology */
if( ! pa || ! pt )
{
lwerror("ptarray_append_point: null input");
return LW_FAILURE;
}
/* Check for duplicate end point */
if ( repeated_points == LW_FALSE && pa->npoints > 0 )
{
POINT4D tmp;
getPoint4d_p(pa, pa->npoints-1, &tmp);
LWDEBUGF(4,"checking for duplicate end point (pt = POINT(%g %g) pa->npoints-q = POINT(%g %g))",pt->x,pt->y,tmp.x,tmp.y);
/* Return LW_SUCCESS and do nothing else if previous point in list is equal to this one */
if ( (pt->x == tmp.x) && (pt->y == tmp.y) &&
(FLAGS_GET_Z(pa->flags) ? pt->z == tmp.z : 1) &&
(FLAGS_GET_M(pa->flags) ? pt->m == tmp.m : 1) )
{
return LW_SUCCESS;
}
}
/* Append is just a special case of insert */
return ptarray_insert_point(pa, pt, pa->npoints);
}
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 = 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;
}
/*
* Add a point into a pointarray. Only adds as many dimensions as the
* pointarray supports.
*/
int
ptarray_remove_point(POINTARRAY *pa, uint32_t where)
{
/* Check for pathology */
if( ! pa )
{
lwerror("ptarray_remove_point: null input");
return LW_FAILURE;
}
/* Error on invalid offset value */
if ( where >= pa->npoints )
{
lwerror("ptarray_remove_point: offset out of range (%d)", where);
return LW_FAILURE;
}
/* If the point is any but the last, we need to copy the data back one point */
if (where < pa->npoints - 1)
memmove(getPoint_internal(pa, where),
getPoint_internal(pa, where + 1),
ptarray_point_size(pa) * (pa->npoints - where - 1));
/* We have one less point */
pa->npoints--;
return LW_SUCCESS;
}
/**
* Build a new #POINTARRAY, but on top of someone else's ordinate array.
* Flag as read-only, so that ptarray_free() does not free the serialized_ptlist
*/
POINTARRAY* ptarray_construct_reference_data(char hasz, char hasm, uint32_t npoints, uint8_t *ptlist)
{
POINTARRAY *pa = lwalloc(sizeof(POINTARRAY));
LWDEBUGF(5, "hasz = %d, hasm = %d, npoints = %d, ptlist = %p", hasz, hasm, npoints, ptlist);
pa->flags = lwflags(hasz, hasm, 0);
FLAGS_SET_READONLY(pa->flags, 1); /* We don't own this memory, so we can't alter or free it. */
pa->npoints = npoints;
pa->maxpoints = npoints;
pa->serialized_pointlist = ptlist;
return pa;
}
POINTARRAY*
ptarray_construct_copy_data(char hasz, char hasm, uint32_t npoints, const uint8_t *ptlist)
{
POINTARRAY *pa = lwalloc(sizeof(POINTARRAY));
pa->flags = lwflags(hasz, hasm, 0);
pa->npoints = npoints;
pa->maxpoints = npoints;
if ( npoints > 0 )
{
pa->serialized_pointlist = lwalloc(ptarray_point_size(pa) * npoints);
memcpy(pa->serialized_pointlist, ptlist, ptarray_point_size(pa) * npoints);
}
else
{
pa->serialized_pointlist = NULL;
}
return pa;
}
void
ptarray_free(POINTARRAY *pa)
{
if (pa)
{
if (pa->serialized_pointlist && (!FLAGS_GET_READONLY(pa->flags)))
lwfree(pa->serialized_pointlist);
lwfree(pa);
}
}
void
ptarray_reverse_in_place(POINTARRAY *pa)
{
if (!pa->npoints)
return;
uint32_t i;
uint32_t last = pa->npoints - 1;
uint32_t mid = pa->npoints / 2;
double *d = (double*)(pa->serialized_pointlist);
int j;
int ndims = FLAGS_NDIMS(pa->flags);
for (i = 0; i < mid; i++)
{
for (j = 0; j < ndims; j++)
{
double buf;
buf = d[i*ndims+j];
d[i*ndims+j] = d[(last-i)*ndims+j];
d[(last-i)*ndims+j] = buf;
}
}
return;
}
/**
* Reverse X and Y axis on a given POINTARRAY
*/
POINTARRAY*
ptarray_flip_coordinates(POINTARRAY *pa)
{
uint32_t i;
double d;
POINT4D p;
for (i=0 ; i < pa->npoints ; i++)
{
getPoint4d_p(pa, i, &p);
d = p.y;
p.y = p.x;
p.x = d;
ptarray_set_point4d(pa, i, &p);
}
return pa;
}
void
ptarray_swap_ordinates(POINTARRAY *pa, LWORD o1, LWORD o2)
{
uint32_t i;
double d, *dp1, *dp2;
POINT4D p;
dp1 = ((double*)&p)+(unsigned)o1;
dp2 = ((double*)&p)+(unsigned)o2;
for (i=0 ; i < pa->npoints ; i++)
{
getPoint4d_p(pa, i, &p);
d = *dp2;
*dp2 = *dp1;
*dp1 = d;
ptarray_set_point4d(pa, i, &p);
}
}
/**
* @brief Returns a modified #POINTARRAY so that no segment is
* longer than the given distance (computed using 2d).
*
* Every input point is kept.
* Z and M values for added points (if needed) are set proportionally.
*/
POINTARRAY *
ptarray_segmentize2d(const POINTARRAY *ipa, double dist)
{
double segdist;
POINT4D p1, p2;
POINT4D pbuf;
POINTARRAY *opa;
uint32_t i, j, nseg;
int hasz = FLAGS_GET_Z(ipa->flags);
int hasm = FLAGS_GET_M(ipa->flags);
pbuf.x = pbuf.y = pbuf.z = pbuf.m = 0;
/* Initial storage */
opa = ptarray_construct_empty(hasz, hasm, ipa->npoints);
/* Add first point */
getPoint4d_p(ipa, 0, &p1);
ptarray_append_point(opa, &p1, LW_FALSE);
/* Loop on all other input points */
for (i = 1; i < ipa->npoints; i++)
{
/*
* We use these pointers to avoid
* "strict-aliasing rules break" warning raised
* by gcc (3.3 and up).
*
* It looks that casting a variable address (also
* referred to as "type-punned pointer")
* breaks those "strict" rules.
*/
POINT4D *p1ptr=&p1, *p2ptr=&p2;
double segments;
getPoint4d_p(ipa, i, &p2);
segdist = distance2d_pt_pt((POINT2D *)p1ptr, (POINT2D *)p2ptr);
/* Split input segment into shorter even chunks */
segments = ceil(segdist / dist);
/* Uses INT32_MAX instead of UINT32_MAX to be safe that it fits */
if (segments >= INT32_MAX)
{
lwnotice("%s:%d - %s: Too many segments required (%e)",
__FILE__, __LINE__,__func__, segments);
ptarray_free(opa);
return NULL;
}
nseg = segments;
for (j = 1; j < nseg; j++)
{
pbuf.x = p1.x + (p2.x - p1.x) * j / nseg;
pbuf.y = p1.y + (p2.y - p1.y) * j / nseg;
if (hasz)
pbuf.z = p1.z + (p2.z - p1.z) * j / nseg;
if (hasm)
pbuf.m = p1.m + (p2.m - p1.m) * j / nseg;
ptarray_append_point(opa, &pbuf, LW_FALSE);
LW_ON_INTERRUPT(ptarray_free(opa); return NULL);
}
ptarray_append_point(opa, &p2, (ipa->npoints == 2) ? LW_TRUE : LW_FALSE);
p1 = p2;
LW_ON_INTERRUPT(ptarray_free(opa); return NULL);
}
return opa;
}
char
ptarray_same(const POINTARRAY *pa1, const POINTARRAY *pa2)
{
uint32_t i;
size_t ptsize;
if ( FLAGS_GET_ZM(pa1->flags) != FLAGS_GET_ZM(pa2->flags) ) return LW_FALSE;
LWDEBUG(5,"dimensions are the same");
if ( pa1->npoints != pa2->npoints ) return LW_FALSE;
LWDEBUG(5,"npoints are the same");
ptsize = ptarray_point_size(pa1);
LWDEBUGF(5, "ptsize = %d", ptsize);
for (i=0; i<pa1->npoints; i++)
{
if ( memcmp(getPoint_internal(pa1, i), getPoint_internal(pa2, i), ptsize) )
return LW_FALSE;
LWDEBUGF(5,"point #%d is the same",i);
}
return LW_TRUE;
}
POINTARRAY *
ptarray_addPoint(const POINTARRAY *pa, uint8_t *p, size_t pdims, uint32_t where)
{
POINTARRAY *ret;
POINT4D pbuf;
size_t ptsize = ptarray_point_size(pa);
LWDEBUGF(3, "pa %x p %x size %d where %d",
pa, p, pdims, where);
if ( pdims < 2 || pdims > 4 )
{
lwerror("ptarray_addPoint: point dimension out of range (%d)",
pdims);
return NULL;
}
if ( where > pa->npoints )
{
lwerror("ptarray_addPoint: offset out of range (%d)",
where);
return NULL;
}
LWDEBUG(3, "called with a %dD point");
pbuf.x = pbuf.y = pbuf.z = pbuf.m = 0.0;
memcpy((uint8_t *)&pbuf, p, pdims*sizeof(double));
LWDEBUG(3, "initialized point buffer");
ret = ptarray_construct(FLAGS_GET_Z(pa->flags),
FLAGS_GET_M(pa->flags), pa->npoints+1);
if ( where )
{
memcpy(getPoint_internal(ret, 0), getPoint_internal(pa, 0), ptsize*where);
}
memcpy(getPoint_internal(ret, where), (uint8_t *)&pbuf, ptsize);
if ( where+1 != ret->npoints )
{
memcpy(getPoint_internal(ret, where+1),
getPoint_internal(pa, where),
ptsize*(pa->npoints-where));
}
return ret;
}
POINTARRAY *
ptarray_removePoint(POINTARRAY *pa, uint32_t which)
{
POINTARRAY *ret;
size_t ptsize = ptarray_point_size(pa);
LWDEBUGF(3, "pa %x which %d", pa, which);
#if PARANOIA_LEVEL > 0
if ( which > pa->npoints-1 )
{
lwerror("%s [%d] offset (%d) out of range (%d..%d)", __FILE__, __LINE__,
which, 0, pa->npoints-1);
return NULL;
}
if ( pa->npoints < 3 )
{
lwerror("%s [%d] can't remove a point from a 2-vertex POINTARRAY", __FILE__, __LINE__);
return NULL;
}
#endif
ret = ptarray_construct(FLAGS_GET_Z(pa->flags),
FLAGS_GET_M(pa->flags), pa->npoints-1);
/* copy initial part */
if ( which )
{
memcpy(getPoint_internal(ret, 0), getPoint_internal(pa, 0), ptsize*which);
}
/* copy final part */
if ( which < pa->npoints-1 )
{
memcpy(getPoint_internal(ret, which), getPoint_internal(pa, which+1),
ptsize*(pa->npoints-which-1));
}
return ret;
}
POINTARRAY *
ptarray_merge(POINTARRAY *pa1, POINTARRAY *pa2)
{
POINTARRAY *pa;
size_t ptsize = ptarray_point_size(pa1);
if (FLAGS_GET_ZM(pa1->flags) != FLAGS_GET_ZM(pa2->flags))
lwerror("ptarray_cat: Mixed dimension");
pa = ptarray_construct( FLAGS_GET_Z(pa1->flags),
FLAGS_GET_M(pa1->flags),
pa1->npoints + pa2->npoints);
memcpy( getPoint_internal(pa, 0),
getPoint_internal(pa1, 0),
ptsize*(pa1->npoints));
memcpy( getPoint_internal(pa, pa1->npoints),
getPoint_internal(pa2, 0),
ptsize*(pa2->npoints));
ptarray_free(pa1);
ptarray_free(pa2);
return pa;
}
/**
* @brief Deep clone a pointarray (also clones serialized pointlist)
*/
POINTARRAY *
ptarray_clone_deep(const POINTARRAY *in)
{
POINTARRAY *out = lwalloc(sizeof(POINTARRAY));
LWDEBUG(3, "ptarray_clone_deep called.");
out->flags = in->flags;
out->npoints = in->npoints;
out->maxpoints = in->npoints;
FLAGS_SET_READONLY(out->flags, 0);
if (!in->npoints)
{
// Avoid calling lwalloc of 0 bytes
out->serialized_pointlist = NULL;
}
else
{
size_t size = in->npoints * ptarray_point_size(in);
out->serialized_pointlist = lwalloc(size);
memcpy(out->serialized_pointlist, in->serialized_pointlist, size);
}
return out;
}
/**
* @brief Clone a POINTARRAY object. Serialized pointlist is not copied.
*/
POINTARRAY *
ptarray_clone(const POINTARRAY *in)
{
POINTARRAY *out = lwalloc(sizeof(POINTARRAY));
LWDEBUG(3, "ptarray_clone called.");
out->flags = in->flags;
out->npoints = in->npoints;
out->maxpoints = in->maxpoints;
FLAGS_SET_READONLY(out->flags, 1);
out->serialized_pointlist = in->serialized_pointlist;
return out;
}
/**
* Check for ring closure using whatever dimensionality is declared on the
* pointarray.
*/
int
ptarray_is_closed(const POINTARRAY *in)
{
if (!in)
{
lwerror("ptarray_is_closed: called with null point array");
return 0;
}
if (in->npoints <= 1 ) return in->npoints; /* single-point are closed, empty not closed */
return 0 == memcmp(getPoint_internal(in, 0), getPoint_internal(in, in->npoints-1), ptarray_point_size(in));
}
int
ptarray_is_closed_2d(const POINTARRAY *in)
{
if (!in)
{
lwerror("ptarray_is_closed_2d: called with null point array");
return 0;
}
if (in->npoints <= 1 ) return in->npoints; /* single-point are closed, empty not closed */
return 0 == memcmp(getPoint_internal(in, 0), getPoint_internal(in, in->npoints-1), sizeof(POINT2D) );
}
int
ptarray_is_closed_3d(const POINTARRAY *in)
{
if (!in)
{
lwerror("ptarray_is_closed_3d: called with null point array");
return 0;
}
if (in->npoints <= 1 ) return in->npoints; /* single-point are closed, empty not closed */
return 0 == memcmp(getPoint_internal(in, 0), getPoint_internal(in, in->npoints-1), sizeof(POINT3D) );
}
int
ptarray_is_closed_z(const POINTARRAY *in)
{
if ( FLAGS_GET_Z(in->flags) )
return ptarray_is_closed_3d(in);
else
return ptarray_is_closed_2d(in);
}
/**
* Return 1 if the point is inside the POINTARRAY, -1 if it is outside,
* and 0 if it is on the boundary.
*/
int
ptarray_contains_point(const POINTARRAY *pa, const POINT2D *pt)
{
return ptarray_contains_point_partial(pa, pt, LW_TRUE, NULL);
}
int
ptarray_contains_point_partial(const POINTARRAY *pa, const POINT2D *pt, int check_closed, int *winding_number)
{
int wn = 0;
uint32_t 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 increment.
*/
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;
}
/**
* For POINTARRAYs representing CIRCULARSTRINGS. That is, linked triples
* with each triple being control points of a circular arc. Such
* POINTARRAYs have an odd number of vertices.
*
* Return 1 if the point is inside the POINTARRAY, -1 if it is outside,
* and 0 if it is on the boundary.
*/
int
ptarrayarc_contains_point(const POINTARRAY *pa, const POINT2D *pt)
{
return ptarrayarc_contains_point_partial(pa, pt, LW_TRUE /* Check closed*/, NULL);
}
int
ptarrayarc_contains_point_partial(const POINTARRAY *pa, const POINT2D *pt, int check_closed, int *winding_number)
{
int wn = 0;
uint32_t i;
int 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 && (seg3->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;
}
/**
* Returns the area in cartesian units. Area is negative if ring is oriented CCW,
* positive if it is oriented CW and zero if the ring is degenerate or flat.
* http://en.wikipedia.org/wiki/Shoelace_formula
*/
double
ptarray_signed_area(const POINTARRAY *pa)
{
const POINT2D *P1;
const POINT2D *P2;
const POINT2D *P3;
double sum = 0.0;
double x0, x, y1, y2;
uint32_t i;
if (! pa || pa->npoints < 3 )
return 0.0;
P1 = getPoint2d_cp(pa, 0);
P2 = getPoint2d_cp(pa, 1);
x0 = P1->x;
for ( i = 2; i < pa->npoints; i++ )
{
P3 = getPoint2d_cp(pa, i);
x = P2->x - x0;
y1 = P3->y;
y2 = P1->y;
sum += x * (y2-y1);
/* Move forwards! */
P1 = P2;
P2 = P3;
}
return sum / 2.0;
}
int
ptarray_isccw(const POINTARRAY *pa)
{
double area = 0;
area = ptarray_signed_area(pa);
if ( area > 0 ) return LW_FALSE;
else return LW_TRUE;
}
POINTARRAY*
ptarray_force_dims(const POINTARRAY *pa, int hasz, int hasm, double zval, double mval)
{
/* TODO handle zero-length point arrays */
uint32_t i;
int in_hasz = FLAGS_GET_Z(pa->flags);
int in_hasm = FLAGS_GET_M(pa->flags);
POINT4D pt;
POINTARRAY *pa_out = ptarray_construct_empty(hasz, hasm, pa->npoints);
for( i = 0; i < pa->npoints; i++ )
{
getPoint4d_p(pa, i, &pt);
if( hasz && ! in_hasz )
pt.z = zval;
if( hasm && ! in_hasm )
pt.m = mval;
ptarray_append_point(pa_out, &pt, LW_TRUE);
}
return pa_out;
}
POINTARRAY *
ptarray_substring(POINTARRAY *ipa, double from, double to, double tolerance)
{
POINTARRAY *dpa;
POINT4D pt;
POINT4D p1, p2;
POINT4D *p1ptr=&p1; /* don't break strict-aliasing rule */
POINT4D *p2ptr=&p2;
int nsegs, i;
double length, slength, tlength;
int state = 0; /* 0=before, 1=inside */
/*
* Create a dynamic pointarray with an initial capacity
* equal to full copy of input points
*/
dpa = ptarray_construct_empty(FLAGS_GET_Z(ipa->flags), FLAGS_GET_M(ipa->flags), ipa->npoints);
/* Compute total line length */
length = ptarray_length_2d(ipa);
LWDEBUGF(3, "Total length: %g", length);
/* Get 'from' and 'to' lengths */
from = length*from;
to = length*to;
LWDEBUGF(3, "From/To: %g/%g", from, to);
tlength = 0;
getPoint4d_p(ipa, 0, &p1);
nsegs = ipa->npoints - 1;
for ( i = 0; i < nsegs; i++ )
{
double dseg;
getPoint4d_p(ipa, i+1, &p2);
LWDEBUGF(3 ,"Segment %d: (%g,%g,%g,%g)-(%g,%g,%g,%g)",
i, p1.x, p1.y, p1.z, p1.m, p2.x, p2.y, p2.z, p2.m);
/* Find the length of this segment */
slength = distance2d_pt_pt((POINT2D *)p1ptr, (POINT2D *)p2ptr);
/*
* We are before requested start.
*/
if ( state == 0 ) /* before */
{
LWDEBUG(3, " Before start");
if ( fabs ( from - ( tlength + slength ) ) <= tolerance )
{
LWDEBUG(3, " Second point is our start");
/*
* Second point is our start
*/
ptarray_append_point(dpa, &p2, LW_FALSE);
state=1; /* we're inside now */
goto END;
}
else if ( fabs(from - tlength) <= tolerance )
{
LWDEBUG(3, " First point is our start");
/*
* First point is our start
*/
ptarray_append_point(dpa, &p1, LW_FALSE);
/*
* We're inside now, but will check
* 'to' point as well
*/
state=1;
}
/*
* Didn't reach the 'from' point,
* nothing to do
*/
else if ( from > tlength + slength ) goto END;
else /* tlength < from < tlength+slength */
{
LWDEBUG(3, " Seg contains first point");
/*
* Our start is between first and
* second point
*/
dseg = (from - tlength) / slength;
interpolate_point4d(&p1, &p2, &pt, dseg);
ptarray_append_point(dpa, &pt, LW_FALSE);
/*
* We're inside now, but will check
* 'to' point as well
*/
state=1;
}
}
if ( state == 1 ) /* inside */
{
LWDEBUG(3, " Inside");
/*
* 'to' point is our second point.
*/
if ( fabs(to - ( tlength + slength ) ) <= tolerance )
{
LWDEBUG(3, " Second point is our end");
ptarray_append_point(dpa, &p2, LW_FALSE);
break; /* substring complete */
}
/*
* 'to' point is our first point.
* (should only happen if 'to' is 0)
*/
else if ( fabs(to - tlength) <= tolerance )
{
LWDEBUG(3, " First point is our end");
ptarray_append_point(dpa, &p1, LW_FALSE);
break; /* substring complete */
}
/*
* Didn't reach the 'end' point,
* just copy second point
*/
else if ( to > tlength + slength )
{
ptarray_append_point(dpa, &p2, LW_FALSE);
goto END;
}
/*
* 'to' point falls on this segment
* Interpolate and break.
*/
else if ( to < tlength + slength )
{
LWDEBUG(3, " Seg contains our end");
dseg = (to - tlength) / slength;
interpolate_point4d(&p1, &p2, &pt, dseg);
ptarray_append_point(dpa, &pt, LW_FALSE);
break;
}
else
{
LWDEBUG(3, "Unhandled case");
}
}
END:
tlength += slength;
memcpy(&p1, &p2, sizeof(POINT4D));
}
LWDEBUGF(3, "Out of loop, ptarray has %d points", dpa->npoints);
return dpa;
}
/*
* Write into the *ret argument coordinates of the closes point on
* the given segment to the reference input point.
*/
void
closest_point_on_segment(const POINT4D *p, const POINT4D *A, const POINT4D *B, POINT4D *ret)
{
double r;
if ( FP_EQUALS(A->x, B->x) && FP_EQUALS(A->y, B->y) )
{
*ret = *A;
return;
}
/*
* We use comp.graphics.algorithms Frequently Asked Questions method
*
* (1) AC dot AB
* r = ----------
* ||AB||^2
* r has the following meaning:
* r=0 P = A
* r=1 P = B
* r<0 P is on the backward extension of AB
* r>1 P is on the forward extension of AB
* 0<r<1 P is interior to AB
*
*/
r = ( (p->x-A->x) * (B->x-A->x) + (p->y-A->y) * (B->y-A->y) )/( (B->x-A->x)*(B->x-A->x) +(B->y-A->y)*(B->y-A->y) );
if (r<=0)
{
*ret = *A;
return;
}
if (r>=1)
{
*ret = *B;
return;
}
ret->x = A->x + ( (B->x - A->x) * r );
ret->y = A->y + ( (B->y - A->y) * r );
ret->z = A->z + ( (B->z - A->z) * r );
ret->m = A->m + ( (B->m - A->m) * r );
}
int
ptarray_closest_segment_2d(const POINTARRAY *pa, const POINT2D *qp, double *dist)
{
const POINT2D *start = getPoint2d_cp(pa, 0), *end = NULL;
uint32_t t, seg=0;
double mindist=DBL_MAX;
/* Loop through pointarray looking for nearest segment */
for (t=1; t<pa->npoints; t++)
{
double dist_sqr;
end = getPoint2d_cp(pa, t);
dist_sqr = distance2d_sqr_pt_seg(qp, start, end);
if (dist_sqr < mindist)
{
mindist = dist_sqr;
seg=t-1;
if ( mindist == 0 )
{
LWDEBUG(3, "Breaking on mindist=0");
break;
}
}
start = end;
}
if ( dist ) *dist = sqrt(mindist);
return seg;
}
int
ptarray_closest_vertex_2d(const POINTARRAY *pa, const POINT2D *qp, double *dist)
{
uint32_t t, pn=0;
const POINT2D *p;
double mindist = DBL_MAX;
/* Loop through pointarray looking for nearest segment */
for (t=0; t<pa->npoints; t++)
{
double dist_sqr;
p = getPoint2d_cp(pa, t);
dist_sqr = distance2d_sqr_pt_pt(p, qp);
if (dist_sqr < mindist)
{
mindist = dist_sqr;
pn = t;
if ( mindist == 0 )
{
LWDEBUG(3, "Breaking on mindist=0");
break;
}
}
}
if ( dist ) *dist = sqrt(mindist);
return pn;
}
/*
* 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=DBL_MAX;
double tlen, plen;
uint32_t t, seg=0;
POINT4D start4d, end4d, projtmp;
POINT2D proj, p;
const POINT2D *start = NULL, *end = NULL;
/* Initialize our 2D copy of the input parameter */
p.x = p4d->x;
p.y = p4d->y;
if ( ! proj4d ) proj4d = &projtmp;
/* Check for special cases (length 0 and 1) */
if ( pa->npoints <= 1 )
{
if ( pa->npoints == 1 )
{
getPoint4d_p(pa, 0, proj4d);
if ( mindistout )
*mindistout = distance2d_pt_pt(&p, getPoint2d_cp(pa, 0));
}
return 0.0;
}
start = getPoint2d_cp(pa, 0);
/* Loop through pointarray looking for nearest segment */
for (t=1; t<pa->npoints; t++)
{
double dist_sqr;
end = getPoint2d_cp(pa, t);
dist_sqr = distance2d_sqr_pt_seg(&p, start, end);
if (dist_sqr < mindist)
{
mindist = dist_sqr;
seg=t-1;
if ( mindist == 0 )
{
LWDEBUG(3, "Breaking on mindist=0");
break;
}
}
start = end;
}
mindist = sqrt(mindist);
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;
start = getPoint2d_cp(pa, 0);
for (t=0; t<seg; t++, start=end)
{
end = getPoint2d_cp(pa, t+1);
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;
}
/**
* @brief Longitude shift for a pointarray.
* Y remains the same
* X is converted:
* from -180..180 to 0..360
* from 0..360 to -180..180
* X < 0 becomes X + 360
* X > 180 becomes X - 360
*/
void
ptarray_longitude_shift(POINTARRAY *pa)
{
uint32_t i;
double x;
for (i=0; i<pa->npoints; i++)
{
memcpy(&x, getPoint_internal(pa, i), sizeof(double));
if ( x < 0 ) x+= 360;
else if ( x > 180 ) x -= 360;
memcpy(getPoint_internal(pa, i), &x, sizeof(double));
}
}
/*
* Returns a POINTARRAY with consecutive equal points
* removed. Equality test on all dimensions of input.
*
* Always returns a newly allocated object.
*/
static POINTARRAY *
ptarray_remove_repeated_points_minpoints(const POINTARRAY *in, double tolerance, int minpoints)
{
POINTARRAY *out = ptarray_clone_deep(in);
ptarray_remove_repeated_points_in_place(out, tolerance, minpoints);
return out;
}
POINTARRAY *
ptarray_remove_repeated_points(const POINTARRAY *in, double tolerance)
{
return ptarray_remove_repeated_points_minpoints(in, tolerance, 2);
}
void
ptarray_remove_repeated_points_in_place(POINTARRAY *pa, double tolerance, uint32_t min_points)
{
uint32_t i;
double tolsq = tolerance * tolerance;
const POINT2D *last = NULL;
const POINT2D *pt;
uint32_t n_points = pa->npoints;
uint32_t n_points_out = 1;
size_t pt_size = ptarray_point_size(pa);
double dsq = FLT_MAX;
/* No-op on short inputs */
if ( n_points <= min_points ) return;
last = getPoint2d_cp(pa, 0);
void *p_to = ((char *)last) + pt_size;
for (i = 1; i < n_points; i++)
{
int last_point = (i == n_points - 1);
/* Look straight into the abyss */
pt = getPoint2d_cp(pa, i);
/* Don't drop points if we are running short of points */
if (n_points + n_points_out > min_points + i)
{
if (tolerance > 0.0)
{
/* Only drop points that are within our tolerance */
dsq = distance2d_sqr_pt_pt(last, pt);
/* Allow any point but the last one to be dropped */
if (!last_point && dsq <= tolsq)
{
continue;
}
}
else
{
/* At tolerance zero, only skip exact dupes */
if (memcmp((char*)pt, (char*)last, pt_size) == 0)
continue;
}
/* Got to last point, and it's not very different from */
/* the point that preceded it. We want to keep the last */
/* point, not the second-to-last one, so we pull our write */
/* index back one value */
if (last_point && n_points_out > 1 && tolerance > 0.0 && dsq <= tolsq)
{
n_points_out--;
p_to = (char*)p_to - pt_size;
}
}
/* Compact all remaining values to front of array */
memcpy(p_to, pt, pt_size);
n_points_out++;
p_to = (char*)p_to + pt_size;
last = pt;
}
/* Adjust array length */
pa->npoints = n_points_out;
return;
}
/* Out of the points in pa [itfist .. itlast], finds the one that's farthest away from
* the segment determined by pts[itfist] and pts[itlast].
* Returns itfirst if no point was found futher away than max_distance_sqr
*/
static uint32_t
ptarray_dp_findsplit_in_place(const POINTARRAY *pts, uint32_t it_first, uint32_t it_last, double max_distance_sqr)
{
uint32_t split = it_first;
if ((it_first - it_last) < 2)
return it_first;
const POINT2D *A = getPoint2d_cp(pts, it_first);
const POINT2D *B = getPoint2d_cp(pts, it_last);
if (distance2d_sqr_pt_pt(A, B) < DBL_EPSILON)
{
/* If p1 == p2, we can just calculate the distance from each point to A */
for (uint32_t itk = it_first + 1; itk < it_last; itk++)
{
const POINT2D *pk = getPoint2d_cp(pts, itk);
double distance_sqr = distance2d_sqr_pt_pt(pk, A);
if (distance_sqr > max_distance_sqr)
{
split = itk;
max_distance_sqr = distance_sqr;
}
}
return split;
}
/* This is based on distance2d_sqr_pt_seg, but heavily inlined here to avoid recalculations */
double ba_x = (B->x - A->x);
double ba_y = (B->y - A->y);
double ab_length_sqr = (ba_x * ba_x + ba_y * ba_y);
/* To avoid the division by ab_length_sqr in the 3rd path, we normalize here
* and multiply in the first two paths [(dot_ac_ab < 0) and (> ab_length_sqr)] */
max_distance_sqr *= ab_length_sqr;
for (uint32_t itk = it_first + 1; itk < it_last; itk++)
{
const POINT2D *C = getPoint2d_cp(pts, itk);
double distance_sqr;
double ca_x = (C->x - A->x);
double ca_y = (C->y - A->y);
double dot_ac_ab = (ca_x * ba_x + ca_y * ba_y);
if (dot_ac_ab <= 0.0)
{
distance_sqr = distance2d_sqr_pt_pt(C, A) * ab_length_sqr;
}
else if (dot_ac_ab >= ab_length_sqr)
{
distance_sqr = distance2d_sqr_pt_pt(C, B) * ab_length_sqr;
}
else
{
double s_numerator = ca_x * ba_y - ca_y * ba_x;
distance_sqr = s_numerator * s_numerator; /* Missing division by ab_length_sqr on purpose */
}
if (distance_sqr > max_distance_sqr)
{
split = itk;
max_distance_sqr = distance_sqr;
}
}
return split;
}
/* O(N) simplification for tolearnce = 0 */
static void
ptarray_simplify_in_place_tolerance0(POINTARRAY *pa)
{
uint32_t kept_it = 0;
uint32_t last_it = pa->npoints - 1;
const POINT2D *kept_pt = getPoint2d_cp(pa, 0);
const size_t pt_size = ptarray_point_size(pa);
for (uint32_t i = 1; i < last_it; i++)
{
const POINT2D *curr_pt = getPoint2d_cp(pa, i);
const POINT2D *next_pt = getPoint2d_cp(pa, i + 1);
double ba_x = next_pt->x - kept_pt->x;
double ba_y = next_pt->y - kept_pt->y;
double ab_length_sqr = ba_x * ba_x + ba_y * ba_y;
double ca_x = curr_pt->x - kept_pt->x;
double ca_y = curr_pt->y - kept_pt->y;
double dot_ac_ab = ca_x * ba_x + ca_y * ba_y;
double s_numerator = ca_x * ba_y - ca_y * ba_x;
if (dot_ac_ab < 0.0 || dot_ac_ab > ab_length_sqr || s_numerator != 0)
{
kept_it++;
kept_pt = curr_pt;
if (kept_it != i)
memcpy(pa->serialized_pointlist + pt_size * kept_it,
pa->serialized_pointlist + pt_size * i,
pt_size);
}
}
/* Append last point */
kept_it++;
if (kept_it != last_it)
memcpy(pa->serialized_pointlist + pt_size * kept_it,
pa->serialized_pointlist + pt_size * last_it,
pt_size);
pa->npoints = kept_it + 1;
}
void
ptarray_simplify_in_place(POINTARRAY *pa, double tolerance, uint32_t minpts)
{
/* Do not try to simplify really short things */
if (pa->npoints < 3 || pa->npoints <= minpts)
return;
if (tolerance == 0 && minpts <= 2)
{
ptarray_simplify_in_place_tolerance0(pa);
return;
}
/* We use this array to keep track of the points we are keeping, so
* we store just TRUE / FALSE in their position */
uint8_t *kept_points = lwalloc(sizeof(uint8_t) * pa->npoints);
memset(kept_points, LW_FALSE, sizeof(uint8_t) * pa->npoints);
kept_points[0] = LW_TRUE;
kept_points[pa->npoints - 1] = LW_TRUE;
uint32_t keptn = 2;
/* We use this array as a stack to store the iterators that we are going to need
* in the following steps.
* This is ~10% faster than iterating over @kept_points looking for them
*/
uint32_t *iterator_stack = lwalloc(sizeof(uint32_t) * pa->npoints);
iterator_stack[0] = 0;
uint32_t iterator_stack_size = 1;
uint32_t it_first = 0;
uint32_t it_last = pa->npoints - 1;
const double tolerance_sqr = tolerance * tolerance;
/* For the first @minpts points we ignore the tolerance */
double it_tol = keptn >= minpts ? tolerance_sqr : -1.0;
while (iterator_stack_size)
{
uint32_t split = ptarray_dp_findsplit_in_place(pa, it_first, it_last, it_tol);
if (split == it_first)
{
it_first = it_last;
it_last = iterator_stack[--iterator_stack_size];
}
else
{
kept_points[split] = LW_TRUE;
keptn++;
iterator_stack[iterator_stack_size++] = it_last;
it_last = split;
it_tol = keptn >= minpts ? tolerance_sqr : -1.0;
}
}
const size_t pt_size = ptarray_point_size(pa);
/* The first point is already in place, so we don't need to copy it */
size_t kept_it = 1;
if (keptn == 2)
{
/* If there are 2 points remaining, it has to be first and last as
* we added those at the start */
memcpy(pa->serialized_pointlist + pt_size * kept_it,
pa->serialized_pointlist + pt_size * (pa->npoints - 1),
pt_size);
}
else if (pa->npoints != keptn) /* We don't need to move any points if we are keeping them all */
{
for (uint32_t i = 1; i < pa->npoints; i++)
{
if (kept_points[i])
{
memcpy(pa->serialized_pointlist + pt_size * kept_it,
pa->serialized_pointlist + pt_size * i,
pt_size);
kept_it++;
}
}
}
pa->npoints = keptn;
lwfree(kept_points);
lwfree(iterator_stack);
}
/************************************************************************/
/**
* Find the 2d length of the given #POINTARRAY, using circular
* arc interpolation between each coordinate triple.
* Length(A1, A2, A3, A4, A5) = Length(A1, A2, A3)+Length(A3, A4, A5)
*/
double
ptarray_arc_length_2d(const POINTARRAY *pts)
{
double dist = 0.0;
uint32_t i;
const POINT2D *a1;
const POINT2D *a2;
const POINT2D *a3;
if ( pts->npoints % 2 != 1 )
lwerror("arc point array with even number of points");
a1 = getPoint2d_cp(pts, 0);
for ( i=2; i < pts->npoints; i += 2 )
{
a2 = getPoint2d_cp(pts, i-1);
a3 = getPoint2d_cp(pts, i);
dist += lw_arc_length(a1, a2, a3);
a1 = a3;
}
return dist;
}
/**
* Find the 2d length of the given #POINTARRAY (even if it's 3d)
*/
double
ptarray_length_2d(const POINTARRAY *pts)
{
double dist = 0.0;
uint32_t i;
const POINT2D *frm;
const POINT2D *to;
if ( pts->npoints < 2 ) return 0.0;
frm = getPoint2d_cp(pts, 0);
for ( i=1; i < pts->npoints; i++ )
{
to = getPoint2d_cp(pts, i);
dist += sqrt( ((frm->x - to->x)*(frm->x - to->x)) +
((frm->y - to->y)*(frm->y - to->y)) );
frm = to;
}
return dist;
}
/**
* Find the 3d/2d length of the given #POINTARRAY
* (depending on its dimensionality)
*/
double
ptarray_length(const POINTARRAY *pts)
{
double dist = 0.0;
uint32_t i;
POINT3DZ frm;
POINT3DZ to;
if ( pts->npoints < 2 ) return 0.0;
/* compute 2d length if 3d is not available */
if ( ! FLAGS_GET_Z(pts->flags) ) return ptarray_length_2d(pts);
getPoint3dz_p(pts, 0, &frm);
for ( i=1; i < pts->npoints; i++ )
{
getPoint3dz_p(pts, i, &to);
dist += sqrt( ((frm.x - to.x)*(frm.x - to.x)) +
((frm.y - to.y)*(frm.y - to.y)) +
((frm.z - to.z)*(frm.z - to.z)) );
frm = to;
}
return dist;
}
/**
* Affine transform a pointarray.
*/
void
ptarray_affine(POINTARRAY *pa, const AFFINE *a)
{
if (FLAGS_GET_Z(pa->flags))
{
for (uint32_t i = 0; i < pa->npoints; i++)
{
POINT4D *p4d = (POINT4D *)(getPoint_internal(pa, i));
double x = p4d->x;
double y = p4d->y;
double z = p4d->z;
p4d->x = a->afac * x + a->bfac * y + a->cfac * z + a->xoff;
p4d->y = a->dfac * x + a->efac * y + a->ffac * z + a->yoff;
p4d->z = a->gfac * x + a->hfac * y + a->ifac * z + a->zoff;
}
}
else
{
for (uint32_t i = 0; i < pa->npoints; i++)
{
POINT2D *pt = (POINT2D *)(getPoint_internal(pa, i));
double x = pt->x;
double y = pt->y;
pt->x = a->afac * x + a->bfac * y + a->xoff;
pt->y = a->dfac * x + a->efac * y + a->yoff;
}
}
}
/**
* WARNING, make sure you send in only 16-member double arrays
* or obviously things will go pear-shaped fast.
*/
#if 0
static int gluInvertMatrix(const double *m, double *invOut)
{
double inv[16], det;
int i;
inv[0] = m[5] * m[10] * m[15] -
m[5] * m[11] * m[14] -
m[9] * m[6] * m[15] +
m[9] * m[7] * m[14] +
m[13] * m[6] * m[11] -
m[13] * m[7] * m[10];
inv[4] = -m[4] * m[10] * m[15] +
m[4] * m[11] * m[14] +
m[8] * m[6] * m[15] -
m[8] * m[7] * m[14] -
m[12] * m[6] * m[11] +
m[12] * m[7] * m[10];
inv[8] = m[4] * m[9] * m[15] -
m[4] * m[11] * m[13] -
m[8] * m[5] * m[15] +
m[8] * m[7] * m[13] +
m[12] * m[5] * m[11] -
m[12] * m[7] * m[9];
inv[12] = -m[4] * m[9] * m[14] +
m[4] * m[10] * m[13] +
m[8] * m[5] * m[14] -
m[8] * m[6] * m[13] -
m[12] * m[5] * m[10] +
m[12] * m[6] * m[9];
inv[1] = -m[1] * m[10] * m[15] +
m[1] * m[11] * m[14] +
m[9] * m[2] * m[15] -
m[9] * m[3] * m[14] -
m[13] * m[2] * m[11] +
m[13] * m[3] * m[10];
inv[5] = m[0] * m[10] * m[15] -
m[0] * m[11] * m[14] -
m[8] * m[2] * m[15] +
m[8] * m[3] * m[14] +
m[12] * m[2] * m[11] -
m[12] * m[3] * m[10];
inv[9] = -m[0] * m[9] * m[15] +
m[0] * m[11] * m[13] +
m[8] * m[1] * m[15] -
m[8] * m[3] * m[13] -
m[12] * m[1] * m[11] +
m[12] * m[3] * m[9];
inv[13] = m[0] * m[9] * m[14] -
m[0] * m[10] * m[13] -
m[8] * m[1] * m[14] +
m[8] * m[2] * m[13] +
m[12] * m[1] * m[10] -
m[12] * m[2] * m[9];
inv[2] = m[1] * m[6] * m[15] -
m[1] * m[7] * m[14] -
m[5] * m[2] * m[15] +
m[5] * m[3] * m[14] +
m[13] * m[2] * m[7] -
m[13] * m[3] * m[6];
inv[6] = -m[0] * m[6] * m[15] +
m[0] * m[7] * m[14] +
m[4] * m[2] * m[15] -
m[4] * m[3] * m[14] -
m[12] * m[2] * m[7] +
m[12] * m[3] * m[6];
inv[10] = m[0] * m[5] * m[15] -
m[0] * m[7] * m[13] -
m[4] * m[1] * m[15] +
m[4] * m[3] * m[13] +
m[12] * m[1] * m[7] -
m[12] * m[3] * m[5];
inv[14] = -m[0] * m[5] * m[14] +
m[0] * m[6] * m[13] +
m[4] * m[1] * m[14] -
m[4] * m[2] * m[13] -
m[12] * m[1] * m[6] +
m[12] * m[2] * m[5];
inv[3] = -m[1] * m[6] * m[11] +
m[1] * m[7] * m[10] +
m[5] * m[2] * m[11] -
m[5] * m[3] * m[10] -
m[9] * m[2] * m[7] +
m[9] * m[3] * m[6];
inv[7] = m[0] * m[6] * m[11] -
m[0] * m[7] * m[10] -
m[4] * m[2] * m[11] +
m[4] * m[3] * m[10] +
m[8] * m[2] * m[7] -
m[8] * m[3] * m[6];
inv[11] = -m[0] * m[5] * m[11] +
m[0] * m[7] * m[9] +
m[4] * m[1] * m[11] -
m[4] * m[3] * m[9] -
m[8] * m[1] * m[7] +
m[8] * m[3] * m[5];
inv[15] = m[0] * m[5] * m[10] -
m[0] * m[6] * m[9] -
m[4] * m[1] * m[10] +
m[4] * m[2] * m[9] +
m[8] * m[1] * m[6] -
m[8] * m[2] * m[5];
det = m[0] * inv[0] + m[1] * inv[4] + m[2] * inv[8] + m[3] * inv[12];
if (det == 0)
return LW_FALSE;
det = 1.0 / det;
for (i = 0; i < 16; i++)
invOut[i] = inv[i] * det;
return LW_TRUE;
}
#endif
/**
* Scale a pointarray.
*/
void
ptarray_scale(POINTARRAY *pa, const POINT4D *fact)
{
uint32_t i;
POINT4D p4d;
LWDEBUG(3, "ptarray_scale start");
for (i=0; i<pa->npoints; i++)
{
getPoint4d_p(pa, i, &p4d);
p4d.x *= fact->x;
p4d.y *= fact->y;
p4d.z *= fact->z;
p4d.m *= fact->m;
ptarray_set_point4d(pa, i, &p4d);
}
LWDEBUG(3, "ptarray_scale end");
}
int
ptarray_startpoint(const POINTARRAY *pa, POINT4D *pt)
{
return getPoint4d_p(pa, 0, pt);
}
/*
* Stick an array of points to the given gridspec.
* Return "gridded" points in *outpts and their number in *outptsn.
*
* Two consecutive points falling on the same grid cell are collapsed
* into one single point.
*
*/
void
ptarray_grid_in_place(POINTARRAY *pa, const gridspec *grid)
{
uint32_t j = 0;
POINT4D *p, *p_out = NULL;
double x, y, z = 0, m = 0;
uint32_t ndims = FLAGS_NDIMS(pa->flags);
uint32_t has_z = FLAGS_GET_Z(pa->flags);
uint32_t has_m = FLAGS_GET_M(pa->flags);
for (uint32_t i = 0; i < pa->npoints; i++)
{
/* Look straight into the abyss */
p = (POINT4D *)(getPoint_internal(pa, i));
x = p->x;
y = p->y;
if (ndims > 2)
z = p->z;
if (ndims > 3)
m = p->m;
if (grid->xsize > 0)
x = rint((x - grid->ipx) / grid->xsize) * grid->xsize + grid->ipx;
if (grid->ysize > 0)
y = rint((y - grid->ipy) / grid->ysize) * grid->ysize + grid->ipy;
/* Read and round this point */
/* Z is always in third position */
if (has_z && grid->zsize > 0)
z = rint((z - grid->ipz) / grid->zsize) * grid->zsize + grid->ipz;
/* M might be in 3rd or 4th position */
if (has_m && grid->msize > 0)
{
/* In POINT ZM, M is in 4th position, in POINT M, M is in 3rd position which is Z in POINT4D */
if (has_z)
m = rint((m - grid->ipm) / grid->msize) * grid->msize + grid->ipm;
else
z = rint((z - grid->ipm) / grid->msize) * grid->msize + grid->ipm;
}
/* Skip duplicates */
if (p_out && p_out->x == x && p_out->y == y && (ndims > 2 ? p_out->z == z : 1) &&
(ndims > 3 ? p_out->m == m : 1))
continue;
/* Write rounded values into the next available point */
p_out = (POINT4D *)(getPoint_internal(pa, j++));
p_out->x = x;
p_out->y = y;
if (ndims > 2)
p_out->z = z;
if (ndims > 3)
p_out->m = m;
}
/* Update output ptarray length */
pa->npoints = j;
return;
}
int
ptarray_npoints_in_rect(const POINTARRAY *pa, const GBOX *gbox)
{
const POINT2D *pt;
int n = 0;
uint32_t i;
for ( i = 0; i < pa->npoints; i++ )
{
pt = getPoint2d_cp(pa, i);
if ( gbox_contains_point2d(gbox, pt) )
n++;
}
return n;
}
/*
* Reorder the vertices of a closed pointarray so that the
* given point is the first/last one.
*
* Error out if pointarray is not closed or it does not
* contain the given point.
*/
int
ptarray_scroll_in_place(POINTARRAY *pa, const POINT4D *pt)
{
POINTARRAY *tmp;
int found;
uint32_t it;
int ptsize;
if ( ! ptarray_is_closed_2d(pa) )
{
lwerror("ptarray_scroll_in_place: input POINTARRAY is not closed");
return LW_FAILURE;
}
ptsize = ptarray_point_size(pa);
/* Find the point in the array */
found = 0;
for ( it = 0; it < pa->npoints; ++it )
{
if ( ! memcmp(getPoint_internal(pa, it), pt, ptsize) )
{
found = 1;
break;
}
}
if ( ! found )
{
lwerror("ptarray_scroll_in_place: input POINTARRAY does not contain the given point");
return LW_FAILURE;
}
if ( 0 == it )
{
/* Point is already the start/end point, just clone the input */
return LW_SUCCESS;
}
/* TODO: reduce allocations */
tmp = ptarray_construct(FLAGS_GET_Z(pa->flags), FLAGS_GET_M(pa->flags), pa->npoints);
bzero(getPoint_internal(tmp, 0), ptsize * pa->npoints);
/* Copy the block from found point to last point into the output array */
memcpy(
getPoint_internal(tmp, 0),
getPoint_internal(pa, it),
ptsize * ( pa->npoints - it )
);
/* Copy the block from second point to the found point into the last portion of the
* return */
memcpy(
getPoint_internal(tmp, pa->npoints - it),
getPoint_internal(pa, 1),
ptsize * ( it )
);
/* Copy the resulting pointarray back to source one */
memcpy(
getPoint_internal(pa, 0),
getPoint_internal(tmp, 0),
ptsize * ( pa->npoints )
);
ptarray_free(tmp);
return LW_SUCCESS;
}
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