lwcollection_split()

static LWGEOM * lwcollection_split ( const LWCOLLECTION *  lwcoll_in, const LWGEOM *  blade_in  )

static

Definition at line 489 of file lwgeom_geos_split.c.

{
        LWGEOM** split_vector=NULL;
        LWCOLLECTION* out;
        size_t split_vector_capacity;
        size_t split_vector_size=0;
        size_t i,j;
 
        split_vector_capacity=8;
        split_vector = lwalloc(split_vector_capacity * sizeof(LWGEOM*));
        if ( ! split_vector )
        {
                lwerror("Out of virtual memory");
                return NULL;
        }
 
        for (i=0; i<lwcoll_in->ngeoms; ++i)
        {
                LWCOLLECTION* col;
                LWGEOM* split = lwgeom_split(lwcoll_in->geoms[i], blade_in);
                /* an exception should prevent this from ever returning NULL */
                if ( ! split ) return NULL;
 
                col = lwgeom_as_lwcollection(split);
                /* Output, if any, will always be a collection */
                assert(col);
 
                /* Reallocate split_vector if needed */
                if ( split_vector_size + col->ngeoms > split_vector_capacity )
                {
                        /* NOTE: we could be smarter on reallocations here */
                        split_vector_capacity += col->ngeoms;
                        split_vector = lwrealloc(split_vector,
                                                 split_vector_capacity * sizeof(LWGEOM*));
                        if ( ! split_vector )
                        {
                                lwerror("Out of virtual memory");
                                return NULL;
                        }
                }
 
                for (j=0; j<col->ngeoms; ++j)
                {
                        col->geoms[j]->srid = SRID_UNKNOWN; /* strip srid */
                        split_vector[split_vector_size++] = col->geoms[j];
                }
                lwfree(col->geoms);
                lwfree(col);
        }
 
        /* Now split_vector has split_vector_size geometries */
        out = lwcollection_construct(COLLECTIONTYPE, lwcoll_in->srid,
                                     NULL, split_vector_size, split_vector);
 
        return (LWGEOM*)out;
}

References COLLECTIONTYPE, LWCOLLECTION::geoms, lwalloc(), lwcollection_construct(), lwerror(), lwfree(), lwgeom_as_lwcollection(), lwgeom_split(), lwrealloc(), LWCOLLECTION::ngeoms, LWGEOM::srid, LWCOLLECTION::srid, and SRID_UNKNOWN.

Referenced by lwgeom_split().

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