Ticket #413: postgis-offsetCurve-RafalMagda.patch

postgis/lwgeom_geos.c

@@ -45 +45 @@
 Datum isvalidreason(PG_FUNCTION_ARGS);
 Datum isvaliddetail(PG_FUNCTION_ARGS);
 Datum buffer(PG_FUNCTION_ARGS);
+Datum offsetcurve(PG_FUNCTION_ARGS);
 Datum intersection(PG_FUNCTION_ARGS);
 Datum convexhull(PG_FUNCTION_ARGS);
 Datum topologypreservesimplify(PG_FUNCTION_ARGS);
@@ -1277 +1278 @@
         PG_RETURN_POINTER(result);
 }
 
+PG_FUNCTION_INFO_V1(offsetcurve);
+Datum offsetcurve(PG_FUNCTION_ARGS)
+{
+#if POSTGIS_GEOS_VERSION >= 32
+        PG_LWGEOM       *geom1;
+        double  size;
+        GEOSGeometry *g1, *g3;
+        PG_LWGEOM *result;
+        int quadsegs = 8; /* the default */
+        int nargs;
+
+        enum
+        {
+                JOIN_ROUND = 1,
+                JOIN_MITRE = 2,
+                JOIN_BEVEL = 3
+        };
+        static const double DEFAULT_MITRE_LIMIT = 5.0;
+        static const int DEFAULT_JOIN_STYLE = JOIN_ROUND;
+
+        double mitreLimit = DEFAULT_MITRE_LIMIT;
+        int joinStyle  = DEFAULT_JOIN_STYLE;
+        int leftSide = 0;
+        char *param;
+        char *params = NULL;
+
+
+        PROFSTART(PROF_QRUN);
+        // geom arg
+        geom1 = (PG_LWGEOM *)  PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
+        // distance/size arg
+        size = PG_GETARG_FLOAT8(1);
+        
+
+        nargs = PG_NARGS();
+
+        initGEOS(lwnotice, lwnotice);
+
+        PROFSTART(PROF_P2G1);
+        g1 = (GEOSGeometry *)POSTGIS2GEOS(geom1);
+        PROFSTOP(PROF_P2G1);
+
+        // side arg
+        param = pstrdup(PG_GETARG_CSTRING(2));
+        POSTGIS_DEBUGF(3, "Param side: %s", param);
+        if ( !strcmp(param, "left") )
+                leftSide = 1;
+        else if( !strcmp(param, "right") )
+                leftSide = 0;
+        else
+        {
+                lwerror("Invalid side string, "
+                        "accept: "
+                        "'left' or 'right' ");
+        }
+        
+        // options arg (optional)
+        if (nargs > 3)
+        {
+                /* We strdup `cause we're going to modify it */
+                params = pstrdup(PG_GETARG_CSTRING(3));
+
+                POSTGIS_DEBUGF(3, "Params: %s", params);
+
+                for (param=params; ; param=NULL)
+                {
+                        char *key, *val;
+                        param = strtok(param, " ");
+                        if ( param == NULL ) break;
+                        POSTGIS_DEBUGF(3, "Param: %s", param);
+
+                        key = param;
+                        val = strchr(key, '=');
+                        if ( val == NULL || *(val+1) == '\0' )
+                        {
+                                lwerror("Missing value for buffer "
+                                        "parameter %s", key);
+                                break;
+                        }
+                        *val = '\0';
+                        ++val;
+
+                        POSTGIS_DEBUGF(3, "Param: %s : %s", key, val);
+
+                        if ( !strcmp(key, "join") )
+                        {
+                                if ( !strcmp(val, "round") )
+                                {
+                                        joinStyle = JOIN_ROUND;
+                                }
+                                else if ( !strcmp(val, "mitre") ||
+                                          !strcmp(val, "miter")    )
+                                {
+                                        joinStyle = JOIN_MITRE;
+                                }
+                                else if ( !strcmp(val, "bevel") )
+                                {
+                                        joinStyle = JOIN_BEVEL;
+                                }
+                                else
+                                {
+                                        lwerror("Invalid buffer end cap "
+                                                "style: %s (accept: "
+                                                "'round', 'mitre', 'miter' "
+                                                " or 'bevel'"
+                                                ")", val);
+                                        break;
+                                }
+                        }
+                        else if ( !strcmp(key, "mitre_limit") ||
+                                  !strcmp(key, "miter_limit")    )
+                        {
+                                /* mitreLimit is a float */
+                                mitreLimit = atof(val);
+                        }
+                        else if ( !strcmp(key, "quad_segs") )
+                        {
+                                /* quadrant segments is an int */
+                                quadsegs = atoi(val);
+                        }
+                        else
+                        {
+                                lwerror("Invalid buffer parameter: %s (accept: "
+                                        "'join', 'mitre_limit', "
+                                        "'miter_limit and "
+                                        "'quad_segs')", key);
+                                break;
+                        }
+                }
+
+                pfree(params); /* was pstrduped */
+
+                POSTGIS_DEBUGF(3, "joinStyle:%d mitreLimit:%g",
+                               joinStyle, mitreLimit);
+
+        }
+
+        PROFSTART(PROF_GRUN);
+        g3 = GEOSSingleSidedBuffer(g1, size, quadsegs,
+                                 joinStyle, mitreLimit, leftSide);
+        PROFSTOP(PROF_GRUN);
+
+        if (g3 == NULL)
+        {
+                elog(ERROR,"GEOS singleSidedBuffer() threw an error!");
+                GEOSGeom_destroy(g1);
+                PG_RETURN_NULL(); /* never get here */
+        }
+
+        POSTGIS_DEBUGF(3, "result: %s", GEOSGeomToWKT(g3));
+
+        GEOSSetSRID(g3, pglwgeom_getSRID(geom1));
+
+        PROFSTART(PROF_G2P);
+        result = GEOS2POSTGIS(g3, TYPE_HASZ(geom1->type));
+        PROFSTOP(PROF_G2P);
+
+        if (result == NULL)
+        {
+                GEOSGeom_destroy(g1);
+                GEOSGeom_destroy(g3);
+                elog(ERROR,"GEOS singleSidedBuffer() threw an error (result postgis geometry formation)!");
+                PG_RETURN_NULL(); /* never get here */
+        }
+        GEOSGeom_destroy(g1);
+        GEOSGeom_destroy(g3);
+
+
+        /* compressType(result); */
+
+        PROFSTOP(PROF_QRUN);
+        PROFREPORT("geos",geom1, NULL, result);
+
+        PG_FREE_IF_COPY(geom1, 0);
+
+        PG_RETURN_POINTER(result);
+#else /* POSTGIS_GEOS_VERSION < 32 */
+        lwerror("The GEOS version this postgis binary "
+        "was compiled against (%d) doesn't support "
+        "offsetcurve function "
+        "(needs 3.2 or higher)",
+        POSTGIS_GEOS_VERSION);
+                        
+        elog(ERROR,"offsetcurve() only in GEOS version >= 3.2 ! Please recompile PostGIS using GEOS version >= 3.2");
+        PG_RETURN_NULL(); /* never get here */
+#endif /* POSTGIS_GEOS_VERSION < 32 */  
+}
+
+
 PG_FUNCTION_INFO_V1(intersection);
 Datum intersection(PG_FUNCTION_ARGS)
 {

postgis/postgis.sql.in.c

@@ -3886 +3886 @@
         AS 'SELECT ST_Buffer($1, $2, $3)'
         LANGUAGE 'SQL' IMMUTABLE STRICT;
 
+-- Availability: 2.0.0 - requires GEOS-3.2 or higher
+CREATE OR REPLACE FUNCTION _ST_OffsetCurve(geometry,float8,cstring,cstring)
+        RETURNS geometry
+        AS 'MODULE_PATHNAME','offsetcurve'
+        LANGUAGE 'C' IMMUTABLE STRICT
+        COST 100;
+
+-- Availability: 2.0.0 - requires GEOS-3.2 or higher
+CREATE OR REPLACE FUNCTION ST_OffsetCurve(geometry,float8,text,text)
+        RETURNS geometry
+        AS $$ SELECT _ST_OffsetCurve($1, $2,
+                CAST( regexp_replace($3, '^[0123456789]+$',
+                        'quad_segs='||$3) AS cstring),
+                CAST( $4 AS cstring)
+                )
+           $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
+-- Availability: 2.0.0 - requires GEOS-3.2 or higher
+CREATE OR REPLACE FUNCTION _ST_OffsetCurve(geometry,float8,cstring)
+        RETURNS geometry
+        AS 'MODULE_PATHNAME','offsetcurve'
+        LANGUAGE 'C' IMMUTABLE STRICT
+        COST 100;
+
+-- Availability: 2.0.0 - requires GEOS-3.2 or higher
+CREATE OR REPLACE FUNCTION ST_OffsetCurve(geometry,float8,text)
+        RETURNS geometry
+        AS $$ SELECT _ST_OffsetCurve($1, $2,
+                CAST( regexp_replace($3, '^[0123456789]+$',
+                        'quad_segs='||$3) AS cstring)
+                )
+           $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
 -- Deprecation in 1.2.3
 CREATE OR REPLACE FUNCTION convexhull(geometry)
         RETURNS geometry