LWPOLY* lwpoly_simplify(const LWPOLY *ipoly, double dist, int preserve_collapsed)
{
int i;
LWPOLY *opoly = lwpoly_construct_empty(ipoly->srid, FLAGS_GET_Z(ipoly->flags), FLAGS_GET_M(ipoly->flags));
LWDEBUGF(2, "%s: simplifying polygon with %d rings", __func__, ipoly->nrings);
if ( lwpoly_is_empty(ipoly) )
{
lwpoly_free(opoly);
return NULL;
}
for ( i = 0; i < ipoly->nrings; i++ )
{
POINTARRAY *opts;
int minvertices = 0;
/* We'll still let holes collapse, but if we're preserving */
/* and this is a shell, we ensure it is kept */
if ( preserve_collapsed && i == 0 )
minvertices = 4;
opts = ptarray_simplify(ipoly->rings[i], dist, minvertices);
LWDEBUGF(3, "ring%d simplified from %d to %d points", i, ipoly->rings[i]->npoints, opts->npoints);
/* Less points than are needed to form a closed ring, we can't use this */
if ( opts->npoints < 4 )
{
LWDEBUGF(3, "ring%d skipped (% pts)", i, opts->npoints);
ptarray_free(opts);
if ( i ) continue;
else break; /* Don't scan holes if shell is collapsed */
}
/* Add ring to simplified polygon */
if( lwpoly_add_ring(opoly, opts) == LW_FAILURE )
{
lwpoly_free(opoly);
return NULL;
}
}
LWDEBUGF(3, "simplified polygon with %d rings", ipoly->nrings);
opoly->type = ipoly->type;
if( lwpoly_is_empty(opoly) )
{
lwpoly_free(opoly);
return NULL;
}
return opoly;
}
LWPOLY* lwpoly_simplify(const LWPOLY *ipoly, double dist)
{
int i;
LWPOLY *opoly = lwpoly_construct_empty(ipoly->srid, FLAGS_GET_Z(ipoly->flags), FLAGS_GET_M(ipoly->flags));
LWDEBUGF(2, "simplify_polygon3d: simplifying polygon with %d rings", ipoly->nrings);
if( lwpoly_is_empty(ipoly) )
return opoly; /* should we return NULL instead ? */
for (i = 0; i < ipoly->nrings; i++)
{
static const int minvertices = 0; /* TODO: allow setting this */
POINTARRAY *opts = ptarray_simplify(ipoly->rings[i], dist, minvertices);
LWDEBUGF(3, "ring%d simplified from %d to %d points", i, ipoly->rings[i]->npoints, opts->npoints);
/* Less points than are needed to form a closed ring, we can't use this */
if ( opts->npoints < 4 )
{
LWDEBUGF(3, "ring%d skipped (% pts)", i, opts->npoints);
ptarray_free(opts);
if ( i ) continue;
else break; /* Don't scan holes if shell is collapsed */
}
/* Add ring to simplified polygon */
if( lwpoly_add_ring(opoly, opts) == LW_FAILURE )
return NULL;
}
LWDEBUGF(3, "simplified polygon with %d rings", ipoly->nrings);
opoly->type = ipoly->type;
if( lwpoly_is_empty(opoly) )
return NULL;
return opoly;
}
