lwline_locate_between_m()

static LWGEOM * lwline_locate_between_m ( LWLINE *  lwline_in, double  m0, double  m1  )

static

Definition at line 552 of file lwgeom_functions_lrs.c.

{
        POINTARRAY *ipa=lwline_in->points;
        int i;
        LWGEOM **geoms;
        int ngeoms;
        int outtype;
        int typeflag=0; /* see flags below */
        const int pointflag=0x01;
        const int lineflag=0x10;
        POINTARRAYSET paset=ptarray_locate_between_m(ipa, m0, m1);
 
        POSTGIS_DEBUGF(2, "lwline_locate_between called for lwline %p", lwline_in);
 
        POSTGIS_DEBUGF(3, " ptarray_locate... returned %d pointarrays",
                 paset.nptarrays);
 
        if ( paset.nptarrays == 0 )
        {
                return NULL;
        }
 
        ngeoms=paset.nptarrays;
        /* TODO: rework this to reduce used memory */
        geoms=lwalloc(sizeof(LWGEOM *)*ngeoms);
        for (i=0; i<ngeoms; i++)
        {
                LWPOINT *lwpoint;
                LWLINE *lwline;
 
                POINTARRAY *pa=paset.ptarrays[i];
 
                /* This is a point */
                if ( pa->npoints == 1 )
                {
                        lwpoint = lwpoint_construct(lwline_in->srid, NULL, pa);
                        geoms[i]=(LWGEOM *)lwpoint;
                        typeflag|=pointflag;
                }
 
                /* This is a line */
                else if ( pa->npoints > 1 )
                {
                        lwline = lwline_construct(lwline_in->srid, NULL, pa);
                        geoms[i]=(LWGEOM *)lwline;
                        typeflag|=lineflag;
                }
 
                /* This is a bug */
                else
                {
                        lwpgerror("ptarray_locate_between_m returned a POINARRAY set containing POINTARRAY with 0 points");
                }
 
        }
 
        if ( ngeoms == 1 )
        {
                return geoms[0];
        }
        else
        {
                /* Choose best type */
                if ( typeflag == 1 ) outtype=MULTIPOINTTYPE;
                else if ( typeflag == 2 ) outtype=MULTILINETYPE;
                else outtype = COLLECTIONTYPE;
 
                return (LWGEOM *)lwcollection_construct(outtype,
                                                        lwline_in->srid, NULL, ngeoms, geoms);
        }
}

References COLLECTIONTYPE, lwalloc(), lwcollection_construct(), lwline_construct(), lwpoint_construct(), MULTILINETYPE, MULTIPOINTTYPE, POINTARRAY::npoints, POINTARRAYSET::nptarrays, LWLINE::points, ptarray_locate_between_m(), POINTARRAYSET::ptarrays, and LWLINE::srid.

Referenced by lwgeom_locate_between_m().

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