自学教程：C++ FLAGS_GET_M函数代码示例

static LWLINE* lwline_from_gserialized_buffer(uint8_t *data_ptr, uint8_t g_flags, size_t *g_size){	uint8_t *start_ptr = data_ptr;	LWLINE *line;	uint32_t npoints = 0;	assert(data_ptr);	line = (LWLINE*)lwalloc(sizeof(LWLINE));	line->srid = SRID_UNKNOWN; /* Default */	line->bbox = NULL;	line->type = LINETYPE;	line->flags = g_flags;	data_ptr += 4; /* Skip past the type. */	npoints = lw_get_uint32_t(data_ptr); /* Zero => empty geometry */	data_ptr += 4; /* Skip past the npoints. */	if ( npoints > 0 )		line->points = ptarray_construct_reference_data(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), npoints, data_ptr);			else		line->points = ptarray_construct(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), 0); /* Empty linestring */	data_ptr += FLAGS_NDIMS(g_flags) * npoints * sizeof(double);	if ( g_size )		*g_size = data_ptr - start_ptr;	return line;}

static LWCIRCSTRING* lwcircstring_from_gserialized_buffer(uint8_t *data_ptr, uint8_t g_flags, size_t *g_size){	uint8_t *start_ptr = data_ptr;	LWCIRCSTRING *circstring;	uint32_t npoints = 0;	assert(data_ptr);	circstring = (LWCIRCSTRING*)lwalloc(sizeof(LWCIRCSTRING));	circstring->srid = SRID_UNKNOWN; /* Default */	circstring->bbox = NULL;	circstring->type = CIRCSTRINGTYPE;	circstring->flags = g_flags;	data_ptr += 4; /* Skip past the circstringtype. */	npoints = lw_get_uint32_t(data_ptr); /* Zero => empty geometry */	data_ptr += 4; /* Skip past the npoints. */	if ( npoints > 0 )		circstring->points = ptarray_construct_reference_data(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), npoints, data_ptr);			else		circstring->points = ptarray_construct(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), 0); /* Empty circularstring */	data_ptr += FLAGS_NDIMS(g_flags) * npoints * sizeof(double);	if ( g_size )		*g_size = data_ptr - start_ptr;	return circstring;}

char* gbox_to_string(const GBOX *gbox){	static int sz = 128;	char *str = NULL;	if ( ! gbox )		return strdup("NULL POINTER");	str = (char*)lwalloc(sz);	if ( FLAGS_GET_GEODETIC(gbox->flags) )	{		snprintf(str, sz, "GBOX((%.8g,%.8g,%.8g),(%.8g,%.8g,%.8g))", gbox->xmin, gbox->ymin, gbox->zmin, gbox->xmax, gbox->ymax, gbox->zmax);		return str;	}	if ( FLAGS_GET_Z(gbox->flags) && FLAGS_GET_M(gbox->flags) )	{		snprintf(str, sz, "GBOX((%.8g,%.8g,%.8g,%.8g),(%.8g,%.8g,%.8g,%.8g))", gbox->xmin, gbox->ymin, gbox->zmin, gbox->mmin, gbox->xmax, gbox->ymax, gbox->zmax, gbox->mmax);		return str;	}	if ( FLAGS_GET_Z(gbox->flags) )	{		snprintf(str, sz, "GBOX((%.8g,%.8g,%.8g),(%.8g,%.8g,%.8g))", gbox->xmin, gbox->ymin, gbox->zmin, gbox->xmax, gbox->ymax, gbox->zmax);		return str;	}	if ( FLAGS_GET_M(gbox->flags) )	{		snprintf(str, sz, "GBOX((%.8g,%.8g,%.8g),(%.8g,%.8g,%.8g))", gbox->xmin, gbox->ymin, gbox->mmin, gbox->xmax, gbox->ymax, gbox->mmax);		return str;	}	snprintf(str, sz, "GBOX((%.8g,%.8g),(%.8g,%.8g))", gbox->xmin, gbox->ymin, gbox->xmax, gbox->ymax);	return str;}

int gbox_overlaps(const GBOX *g1, const GBOX *g2){	/* Make sure our boxes are consistent */	if ( FLAGS_GET_GEODETIC(g1->flags) != FLAGS_GET_GEODETIC(g2->flags) )		lwerror("gbox_overlaps: cannot compare geodetic and non-geodetic boxes");	/* Check X/Y first */	if ( g1->xmax < g2->xmin || g1->ymax < g2->ymin ||	     g1->xmin > g2->xmax || g1->ymin > g2->ymax )		return LW_FALSE;			/* If both geodetic or both have Z, check Z */	if ( (FLAGS_GET_Z(g1->flags) && FLAGS_GET_Z(g2->flags)) || 	     (FLAGS_GET_GEODETIC(g1->flags) && FLAGS_GET_GEODETIC(g2->flags)) )	{		if ( g1->zmax < g2->zmin || g1->zmin > g2->zmax )			return LW_FALSE;	}		/* If both have M, check M */	if ( FLAGS_GET_M(g1->flags) && FLAGS_GET_M(g2->flags) )	{		if ( g1->mmax < g2->mmin || g1->mmin > g2->mmax )			return LW_FALSE;	}		return LW_TRUE;}

static LWPOINT* lwpoint_from_gserialized_buffer(uint8_t *data_ptr, uint8_t g_flags, size_t *g_size){	uint8_t *start_ptr = data_ptr;	LWPOINT *point;	uint32_t npoints = 0;	assert(data_ptr);	point = (LWPOINT*)lwalloc(sizeof(LWPOINT));	point->srid = SRID_UNKNOWN; /* Default */	point->bbox = NULL;	point->type = POINTTYPE;	point->flags = g_flags;	data_ptr += 4; /* Skip past the type. */	npoints = lw_get_uint32_t(data_ptr); /* Zero => empty geometry */	data_ptr += 4; /* Skip past the npoints. */	if ( npoints > 0 )		point->point = ptarray_construct_reference_data(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), 1, data_ptr);	else		point->point = ptarray_construct(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), 0); /* Empty point */	data_ptr += npoints * FLAGS_NDIMS(g_flags) * sizeof(double);	if ( g_size )		*g_size = data_ptr - start_ptr;	return point;}

Datum LWGEOM_m_point(PG_FUNCTION_ARGS){	GSERIALIZED *geom;	LWPOINT *point = NULL;	LWGEOM *lwgeom;	POINT3DM p;	geom = (GSERIALIZED *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));	if ( gserialized_get_type(geom) != POINTTYPE )		lwerror("Argument to M() must be a point");	lwgeom = lwgeom_from_gserialized(geom);	point = lwgeom_as_lwpoint(lwgeom);		if ( lwgeom_is_empty(lwgeom) )		PG_RETURN_NULL();	/* no M in input */	if ( ! FLAGS_GET_M(point->flags) ) PG_RETURN_NULL();	getPoint3dm_p(point->point, 0, &p);	PG_FREE_IF_COPY(geom, 0);	PG_RETURN_FLOAT8(p.m);}

/** * @brief Merge two given POINTARRAY and returns a pointer * on the new aggregate one. * Warning: this function free the two inputs POINTARRAY * @return #POINTARRAY is newly allocated */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));	lwfree(pa1);	lwfree(pa2);	return pa;}

static int lwcircstring_calculate_gbox_cartesian(LWCIRCSTRING *curve, GBOX *gbox){	uint8_t flags = gflags(FLAGS_GET_Z(curve->flags), FLAGS_GET_M(curve->flags), 0);	GBOX tmp;	POINT4D p1, p2, p3;	int i;	if ( ! curve ) return LW_FAILURE;	if ( curve->points->npoints < 3 ) return LW_FAILURE;	tmp.flags = flags;	/* Initialize */	gbox->xmin = gbox->ymin = gbox->zmin = gbox->mmin = MAXFLOAT;	gbox->xmax = gbox->ymax = gbox->zmax = gbox->mmax = -1 * MAXFLOAT;	for ( i = 2; i < curve->points->npoints; i += 2 )	{		getPoint4d_p(curve->points, i-2, &p1);		getPoint4d_p(curve->points, i-1, &p2);		getPoint4d_p(curve->points, i, &p3);		if (lw_arc_calculate_gbox_cartesian(&p1, &p2, &p3, &tmp) == LW_FAILURE)			continue;		gbox_merge(&tmp, gbox);	}	return LW_SUCCESS;}

/*** Create a new point. Null point array implies empty. Null dimensionality* implies no specified dimensionality in the WKT.*/LWGEOM* wkt_parser_point_new(POINTARRAY *pa, char *dimensionality){	uint8_t flags = wkt_dimensionality(dimensionality);	LWDEBUG(4,"entered");		/* No pointarray means it is empty */	if( ! pa )		return lwpoint_as_lwgeom(lwpoint_construct_empty(SRID_UNKNOWN, FLAGS_GET_Z(flags), FLAGS_GET_M(flags)));	/* If the number of dimensions is not consistent, we have a problem. */	if( wkt_pointarray_dimensionality(pa, flags) == LW_FALSE )	{		ptarray_free(pa);		SET_PARSER_ERROR(PARSER_ERROR_MIXDIMS);		return NULL;	}	/* Only one point allowed in our point array! */		if( pa->npoints != 1 )	{		ptarray_free(pa);		SET_PARSER_ERROR(PARSER_ERROR_LESSPOINTS);		return NULL;	}			return lwpoint_as_lwgeom(lwpoint_construct(SRID_UNKNOWN, NULL, pa));}

LWGEOM* wkt_parser_polygon_finalize(LWGEOM *poly, char *dimensionality){	uint8_t flags = wkt_dimensionality(dimensionality);	int flagdims = FLAGS_NDIMS(flags);	LWDEBUG(4,"entered");		/* Null input implies empty return */	if( ! poly )		return lwpoly_as_lwgeom(lwpoly_construct_empty(SRID_UNKNOWN, FLAGS_GET_Z(flags), FLAGS_GET_M(flags)));	/* If the number of dimensions are not consistent, we have a problem. */	if( flagdims > 2 )	{		if ( flagdims != FLAGS_NDIMS(poly->flags) )		{			lwgeom_free(poly);			SET_PARSER_ERROR(PARSER_ERROR_MIXDIMS);			return NULL;		}			/* Harmonize the flags in the sub-components with the wkt flags */		if( LW_FAILURE == wkt_parser_set_dims(poly, flags) )		{			lwgeom_free(poly);			SET_PARSER_ERROR(PARSER_ERROR_OTHER);			return NULL;		}	}		return poly;}

/*** Read the dimensionality from a flag, if provided. Then check that the* dimensionality matches that of the pointarray. If the dimension counts* match, ensure the pointarray is using the right "Z" or "M".*/static int wkt_pointarray_dimensionality(POINTARRAY *pa, uint8_t flags){		int hasz = FLAGS_GET_Z(flags);	int hasm = FLAGS_GET_M(flags);	int ndims = 2 + hasz + hasm;	/* No dimensionality or array means we go with what we have */	if( ! (flags && pa) )		return LW_TRUE;			LWDEBUGF(5,"dimensionality ndims == %d", ndims);	LWDEBUGF(5,"FLAGS_NDIMS(pa->flags) == %d", FLAGS_NDIMS(pa->flags));		/* 	* ndims > 2 implies that the flags have something useful to add,	* that there is a 'Z' or an 'M' or both.	*/	if( ndims > 2 )	{		/* Mismatch implies a problem */		if ( FLAGS_NDIMS(pa->flags) != ndims )			return LW_FALSE;		/* Match means use the explicit dimensionality */		else		{			FLAGS_SET_Z(pa->flags, hasz);			FLAGS_SET_M(pa->flags, hasm);		}	}	return LW_TRUE;}

intptarray_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 gbox_is_valid(const GBOX *gbox){	/* X */	if ( ! isfinite(gbox->xmin) || isnan(gbox->xmin) ||	     ! isfinite(gbox->xmax) || isnan(gbox->xmax) )		return LW_FALSE;			/* Y */	if ( ! isfinite(gbox->ymin) || isnan(gbox->ymin) ||	     ! isfinite(gbox->ymax) || isnan(gbox->ymax) )		return LW_FALSE;			/* Z */	if ( FLAGS_GET_GEODETIC(gbox->flags) || FLAGS_GET_Z(gbox->flags) )	{		if ( ! isfinite(gbox->zmin) || isnan(gbox->zmin) ||		     ! isfinite(gbox->zmax) || isnan(gbox->zmax) )			return LW_FALSE;	}	/* M */	if ( FLAGS_GET_M(gbox->flags) )	{		if ( ! isfinite(gbox->mmin) || isnan(gbox->mmin) ||		     ! isfinite(gbox->mmax) || isnan(gbox->mmax) )			return LW_FALSE;	}		return LW_TRUE;		}

int gbox_merge(const GBOX *new_box, GBOX *merge_box){	assert(merge_box);	if ( FLAGS_GET_ZM(merge_box->flags) != FLAGS_GET_ZM(new_box->flags) )		return LW_FAILURE;	if ( new_box->xmin < merge_box->xmin) merge_box->xmin = new_box->xmin;	if ( new_box->ymin < merge_box->ymin) merge_box->ymin = new_box->ymin;	if ( new_box->xmax > merge_box->xmax) merge_box->xmax = new_box->xmax;	if ( new_box->ymax > merge_box->ymax) merge_box->ymax = new_box->ymax;	if ( FLAGS_GET_Z(merge_box->flags) || FLAGS_GET_GEODETIC(merge_box->flags) )	{		if ( new_box->zmin < merge_box->zmin) merge_box->zmin = new_box->zmin;		if ( new_box->zmax > merge_box->zmax) merge_box->zmax = new_box->zmax;	}	if ( FLAGS_GET_M(merge_box->flags) )	{		if ( new_box->mmin < merge_box->mmin) merge_box->mmin = new_box->mmin;		if ( new_box->mmax > merge_box->mmax) merge_box->mmax = new_box->mmax;	}	return LW_SUCCESS;}

/*** Create a new linestring. Null point array implies empty. Null dimensionality* implies no specified dimensionality in the WKT. Check for numpoints >= 2 if* requested.*/LWGEOM* wkt_parser_linestring_new(POINTARRAY *pa, char *dimensionality){	uint8_t flags = wkt_dimensionality(dimensionality);	LWDEBUG(4,"entered");	/* No pointarray means it is empty */	if( ! pa )		return lwline_as_lwgeom(lwline_construct_empty(SRID_UNKNOWN, FLAGS_GET_Z(flags), FLAGS_GET_M(flags)));	/* If the number of dimensions is not consistent, we have a problem. */	if( wkt_pointarray_dimensionality(pa, flags) == LW_FALSE )	{		ptarray_free(pa);		SET_PARSER_ERROR(PARSER_ERROR_MIXDIMS);		return NULL;	}		/* Apply check for not enough points, if requested. */		if( (global_parser_result.parser_check_flags & LW_PARSER_CHECK_MINPOINTS) && (pa->npoints < 2) )	{		ptarray_free(pa);		SET_PARSER_ERROR(PARSER_ERROR_MOREPOINTS);		return NULL;	}	return lwline_as_lwgeom(lwline_construct(SRID_UNKNOWN, NULL, pa));}

/*** Peak into a #GSERIALIZED datum to find the bounding box. If the* box is there, copy it out and return it. If not, calculate the box from the* full object and return the box based on that. If no box is available,* return #LW_FAILURE, otherwise #LW_SUCCESS.*/int gserialized_datum_get_gidx_p(Datum gsdatum, GIDX *gidx){	GSERIALIZED *gpart;	int result = LW_SUCCESS;	POSTGIS_DEBUG(4, "entered function");	/*	** The most info we need is the 8 bytes of serialized header plus the 32 bytes	** of floats necessary to hold the 8 floats of the largest XYZM index	** bounding box, so 40 bytes.	*/	gpart = (GSERIALIZED*)PG_DETOAST_DATUM_SLICE(gsdatum, 0, 40);	POSTGIS_DEBUGF(4, "got flags %d", gpart->flags);	/* Do we even have a serialized bounding box? */	if ( FLAGS_GET_BBOX(gpart->flags) )	{		/* Yes! Copy it out into the GIDX! */		size_t size = gbox_serialized_size(gpart->flags);		POSTGIS_DEBUG(4, "copying box out of serialization");		memcpy(gidx->c, gpart->data, size);		/* if M is present but Z is not, pad Z and shift M */		if ( FLAGS_GET_M(gpart->flags) && ! FLAGS_GET_Z(gpart->flags) )		{			size += 2 * sizeof(float);			GIDX_SET_MIN(gidx,3,GIDX_GET_MIN(gidx,2));			GIDX_SET_MAX(gidx,3,GIDX_GET_MAX(gidx,2));			GIDX_SET_MIN(gidx,2,-1*FLT_MAX);			GIDX_SET_MAX(gidx,2,FLT_MAX);		}		SET_VARSIZE(gidx, VARHDRSZ + size);		result = LW_SUCCESS;	}	else	{		/* No, we need to calculate it from the full object. */		GSERIALIZED *g = (GSERIALIZED*)PG_DETOAST_DATUM(gsdatum);		LWGEOM *lwgeom = lwgeom_from_gserialized(g);		GBOX gbox;		if ( lwgeom_calculate_gbox(lwgeom, &gbox) == LW_FAILURE )		{			POSTGIS_DEBUG(4, "could not calculate bbox, returning failure");			lwgeom_free(lwgeom);			return LW_FAILURE;		}		lwgeom_free(lwgeom);		result = gidx_from_gbox_p(gbox, gidx);	}		if ( result == LW_SUCCESS )	{		POSTGIS_DEBUGF(4, "got gidx %s", gidx_to_string(gidx));	}	return result;}

LWGEOM* wkt_parser_collection_finalize(int lwtype, LWGEOM *col, char *dimensionality) {	uint8_t flags = wkt_dimensionality(dimensionality);	int flagdims = FLAGS_NDIMS(flags);		/* No geometry means it is empty */	if( ! col )	{		return lwcollection_as_lwgeom(lwcollection_construct_empty(lwtype, SRID_UNKNOWN, FLAGS_GET_Z(flags), FLAGS_GET_M(flags)));	}	/* There are 'Z' or 'M' tokens in the signature */	if ( flagdims > 2 )	{		/* If the number of dimensions are not consistent, we have a problem. */		if( flagdims != FLAGS_NDIMS(col->flags) )		{			lwgeom_free(col);			SET_PARSER_ERROR(PARSER_ERROR_MIXDIMS);			return NULL;		}		/* For GEOMETRYCOLLECTION, the exact type of the dimensions must match too */		if( lwtype == COLLECTIONTYPE &&		    ( (FLAGS_GET_Z(flags) != FLAGS_GET_Z(col->flags)) ||		      (FLAGS_GET_M(flags) != FLAGS_GET_M(col->flags)) ) )		{			lwgeom_free(col);			SET_PARSER_ERROR(PARSER_ERROR_MIXDIMS);			return NULL;		}				/* Harmonize the collection dimensionality */		if( LW_FAILURE == wkt_parser_set_dims(col, flags) )		{			lwgeom_free(col);			SET_PARSER_ERROR(PARSER_ERROR_OTHER);			return NULL;		}	}			/* Set the collection type */	col->type=lwtype;				return col;}

/** Generic GEOMETRY*/static void lwgeom_to_wkt_sb(const LWGEOM *geom, stringbuffer_t *sb, int precision, uint8_t variant){    LWDEBUGF(4, "lwgeom_to_wkt_sb: type %s, hasz %d, hasm %d",             lwtype_name(geom->type), (geom->type),             FLAGS_GET_Z(geom->flags)?1:0, FLAGS_GET_M(geom->flags)?1:0);    switch (geom->type)    {    case POINTTYPE:        lwpoint_to_wkt_sb((LWPOINT*)geom, sb, precision, variant);        break;    case LINETYPE:        lwline_to_wkt_sb((LWLINE*)geom, sb, precision, variant);        break;    case POLYGONTYPE:        lwpoly_to_wkt_sb((LWPOLY*)geom, sb, precision, variant);        break;    case MULTIPOINTTYPE:        lwmpoint_to_wkt_sb((LWMPOINT*)geom, sb, precision, variant);        break;    case MULTILINETYPE:        lwmline_to_wkt_sb((LWMLINE*)geom, sb, precision, variant);        break;    case MULTIPOLYGONTYPE:        lwmpoly_to_wkt_sb((LWMPOLY*)geom, sb, precision, variant);        break;    case COLLECTIONTYPE:        lwcollection_to_wkt_sb((LWCOLLECTION*)geom, sb, precision, variant);        break;    case CIRCSTRINGTYPE:        lwcircstring_to_wkt_sb((LWCIRCSTRING*)geom, sb, precision, variant);        break;    case COMPOUNDTYPE:        lwcompound_to_wkt_sb((LWCOMPOUND*)geom, sb, precision, variant);        break;    case CURVEPOLYTYPE:        lwcurvepoly_to_wkt_sb((LWCURVEPOLY*)geom, sb, precision, variant);        break;    case MULTICURVETYPE:        lwmcurve_to_wkt_sb((LWMCURVE*)geom, sb, precision, variant);        break;    case MULTISURFACETYPE:        lwmsurface_to_wkt_sb((LWMSURFACE*)geom, sb, precision, variant);        break;    case TRIANGLETYPE:        lwtriangle_to_wkt_sb((LWTRIANGLE*)geom, sb, precision, variant);        break;    case TINTYPE:        lwtin_to_wkt_sb((LWTIN*)geom, sb, precision, variant);        break;    case POLYHEDRALSURFACETYPE:        lwpsurface_to_wkt_sb((LWPSURFACE*)geom, sb, precision, variant);        break;    default:        lwerror("lwgeom_to_wkt_sb: Type %d - %s unsupported.",                geom->type, lwtype_name(geom->type));    }}

POINTARRAY *ptarray_simplify(POINTARRAY *inpts, double epsilon, unsigned int minpts){	int *stack;			/* recursion stack */	int sp=-1;			/* recursion stack pointer */	int p1, split;	double dist;	POINTARRAY *outpts;	POINT4D pt;	double eps_sqr = epsilon * epsilon;	/* Allocate recursion stack */	stack = lwalloc(sizeof(int)*inpts->npoints);	p1 = 0;	stack[++sp] = inpts->npoints-1;	LWDEBUGF(2, "Input has %d pts and %d dims", inpts->npoints,	                                            FLAGS_NDIMS(inpts->flags));	/* Allocate output POINTARRAY, and add first point. */	outpts = ptarray_construct_empty(FLAGS_GET_Z(inpts->flags), FLAGS_GET_M(inpts->flags), inpts->npoints);	getPoint4d_p(inpts, 0, &pt);	ptarray_append_point(outpts, &pt, LW_FALSE);	LWDEBUG(3, "Added P0 to simplified point array (size 1)");	do	{		ptarray_dp_findsplit(inpts, p1, stack[sp], &split, &dist);		LWDEBUGF(3, "Farthest point from P%d-P%d is P%d (dist. %g)", p1, stack[sp], split, dist);		if (dist > eps_sqr || ( outpts->npoints+sp+1 < minpts && dist >= 0 ) )		{			LWDEBUGF(4, "Added P%d to stack (outpts:%d)", split, sp);			stack[++sp] = split;		}		else		{			getPoint4d_p(inpts, stack[sp], &pt);			LWDEBUGF(4, "npoints , minpoints %d %d", outpts->npoints, minpts);			ptarray_append_point(outpts, &pt, LW_FALSE);						LWDEBUGF(4, "Added P%d to simplified point array (size: %d)", stack[sp], outpts->npoints);			p1 = stack[sp--];		}		LWDEBUGF(4, "stack pointer = %d", sp);	}	while (! (sp<0) );	lwfree(stack);	return outpts;}

/* Convert a double-based GBOX into a float-based GIDX,   ensuring the float box is larger than the double box */static int gidx_from_gbox_p(GBOX box, GIDX *a){	int ndims;	ndims = (FLAGS_GET_GEODETIC(box.flags) ? 3 : FLAGS_NDIMS(box.flags));	SET_VARSIZE(a, VARHDRSZ + ndims * 2 * sizeof(float));	GIDX_SET_MIN(a,0,nextDown_f(box.xmin));	GIDX_SET_MAX(a,0,nextUp_f(box.xmax));	GIDX_SET_MIN(a,1,nextDown_f(box.ymin));	GIDX_SET_MAX(a,1,nextUp_f(box.ymax));	/* Geodetic indexes are always 3d, geocentric x/y/z */	if ( FLAGS_GET_GEODETIC(box.flags) )	{		GIDX_SET_MIN(a,2,nextDown_f(box.zmin));		GIDX_SET_MAX(a,2,nextUp_f(box.zmax));	}	else	{		/* Cartesian with Z implies Z is third dimension */		if ( FLAGS_GET_Z(box.flags) )		{			GIDX_SET_MIN(a,2,nextDown_f(box.zmin));			GIDX_SET_MAX(a,2,nextUp_f(box.zmax));			if ( FLAGS_GET_M(box.flags) )			{				GIDX_SET_MIN(a,3,nextDown_f(box.mmin));				GIDX_SET_MAX(a,3,nextUp_f(box.mmax));			}		}		/* Unless there's no Z, in which case M is third dimension */		else if ( FLAGS_GET_M(box.flags) )		{			GIDX_SET_MIN(a,2,nextDown_f(box.mmin));			GIDX_SET_MAX(a,2,nextUp_f(box.mmax));		}	}	POSTGIS_DEBUGF(5, "converted %s to %s", gbox_to_string(&box), gidx_to_string(a));	return G_SUCCESS;}

static LWMPOINT*lwgeom_extract_endpoints(const LWGEOM* lwg){	LWMPOINT* col = lwmpoint_construct_empty(SRID_UNKNOWN,	                              FLAGS_GET_Z(lwg->flags),	                              FLAGS_GET_M(lwg->flags));	lwgeom_collect_endpoints(lwg, col);	return col;}

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;}

doublelwpoint_get_m(const LWPOINT *point){	POINT4D pt;	if ( lwpoint_is_empty(point) )		lwerror("lwpoint_get_m called with empty geometry");	if ( ! FLAGS_GET_M(point->flags) )		lwerror("lwpoint_get_m called without m dimension");	getPoint4d_p(point->point, 0, &pt);	return pt.m;}

int gbox_from_gserialized(const GSERIALIZED *g, GBOX *gbox){	/* Null input! */	if ( ! g ) return G_FAILURE;	/* Initialize the flags on the box */	gbox->flags = g->flags;	if ( FLAGS_GET_BBOX(g->flags) )	{		int i = 0;		float *fbox = (float*)(g->data);		gbox->xmin = fbox[i];		i++;		gbox->xmax = fbox[i];		i++;		gbox->ymin = fbox[i];		i++;		gbox->ymax = fbox[i];		i++;		if ( FLAGS_GET_GEODETIC(g->flags) )		{			gbox->zmin = fbox[i];			i++;			gbox->zmax = fbox[i];			i++;			return G_SUCCESS;		}		if ( FLAGS_GET_Z(g->flags) )		{			gbox->zmin = fbox[i];			i++;			gbox->zmax = fbox[i];			i++;		}		if ( FLAGS_GET_M(g->flags) )		{			gbox->mmin = fbox[i];			i++;			gbox->mmax = fbox[i];			i++;		}		return G_SUCCESS;	}	LWDEBUG(4, "calculating new box from scratch");	if ( gserialized_calculate_gbox_geocentric_p(g, gbox) == G_FAILURE )	{		LWDEBUG(4, "calculated null bbox, returning failure");		return G_FAILURE;	}	return G_SUCCESS;}

static LWPOLY* lwpoly_from_gserialized_buffer(uint8_t *data_ptr, uint8_t g_flags, size_t *g_size){	uint8_t *start_ptr = data_ptr;	LWPOLY *poly;	uint8_t *ordinate_ptr;	uint32_t nrings = 0;	int i = 0;	assert(data_ptr);	poly = (LWPOLY*)lwalloc(sizeof(LWPOLY));	poly->srid = SRID_UNKNOWN; /* Default */	poly->bbox = NULL;	poly->type = POLYGONTYPE;	poly->flags = g_flags;	data_ptr += 4; /* Skip past the polygontype. */	nrings = lw_get_uint32_t(data_ptr); /* Zero => empty geometry */	poly->nrings = nrings;	LWDEBUGF(4, "nrings = %d", nrings);	data_ptr += 4; /* Skip past the nrings. */	ordinate_ptr = data_ptr; /* Start the ordinate pointer. */	if ( nrings > 0)	{		poly->rings = (POINTARRAY**)lwalloc( sizeof(POINTARRAY*) * nrings );		ordinate_ptr += nrings * 4; /* Move past all the npoints values. */		if ( nrings % 2 ) /* If there is padding, move past that too. */			ordinate_ptr += 4;	}	else /* Empty polygon */	{		poly->rings = NULL;	}	for ( i = 0; i < nrings; i++ )	{		uint32_t npoints = 0;		/* Read in the number of points. */		npoints = lw_get_uint32_t(data_ptr);		data_ptr += 4;		/* Make a point array for the ring, and move the ordinate pointer past the ring ordinates. */		poly->rings[i] = ptarray_construct_reference_data(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), npoints, ordinate_ptr);				ordinate_ptr += sizeof(double) * FLAGS_NDIMS(g_flags) * npoints;	}	if ( g_size )		*g_size = ordinate_ptr - start_ptr;	return poly;}

/** * @brief Add a point in a pointarray. * * @param pa the source POINTARRAY * @param p the point to add * @param pdims number of ordinates in p (2..4) * @param where to insert the point. 0 prepends, pa->npoints appends * * @returns a newly constructed POINTARRAY using a newly allocated buffer *          for the actual points, or NULL on error. */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 == -1 ) where = pa->npoints;	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;}

/* * @param icurve input curve * @param tol tolerance, semantic driven by tolerance_type * @param tolerance_type see LW_LINEARIZE_TOLERANCE_TYPE * @param flags see flags in lwarc_linearize * * @return a newly allocated LWLINE */static LWLINE *lwcircstring_linearize(const LWCIRCSTRING *icurve, double tol,                        LW_LINEARIZE_TOLERANCE_TYPE tolerance_type,                        int flags){	LWLINE *oline;	POINTARRAY *ptarray;	uint32_t i, j;	POINT4D p1, p2, p3, p4;	int ret;	LWDEBUGF(2, "lwcircstring_linearize called., dim = %d", icurve->points->flags);	ptarray = ptarray_construct_empty(FLAGS_GET_Z(icurve->points->flags), FLAGS_GET_M(icurve->points->flags), 64);	for (i = 2; i < icurve->points->npoints; i+=2)	{		LWDEBUGF(3, "lwcircstring_linearize: arc ending at point %d", i);		getPoint4d_p(icurve->points, i - 2, &p1);		getPoint4d_p(icurve->points, i - 1, &p2);		getPoint4d_p(icurve->points, i, &p3);		ret = lwarc_linearize(ptarray, &p1, &p2, &p3, tol, tolerance_type, flags);		if ( ret > 0 )		{			LWDEBUGF(3, "lwcircstring_linearize: generated %d points", ptarray->npoints);		}		else if ( ret == 0 )		{			LWDEBUG(3, "lwcircstring_linearize: points are colinear, returning curve points as line");			for (j = i - 2 ; j < i ; j++)			{				getPoint4d_p(icurve->points, j, &p4);				ptarray_append_point(ptarray, &p4, LW_TRUE);			}		}		else		{			/* An error occurred, lwerror should have been called by now */			ptarray_free(ptarray);			return NULL;		}	}	getPoint4d_p(icurve->points, icurve->points->npoints-1, &p1);	ptarray_append_point(ptarray, &p1, LW_TRUE);	oline = lwline_construct(icurve->srid, NULL, ptarray);	return oline;}

LWLINE *lwcircstring_segmentize(const LWCIRCSTRING *icurve, uint32_t perQuad){	LWLINE *oline;	POINTARRAY *ptarray;	POINTARRAY *tmp;	uint32_t i, j;	POINT4D p1, p2, p3, p4;	LWDEBUGF(2, "lwcircstring_segmentize called., dim = %d", icurve->points->flags);	ptarray = ptarray_construct_empty(FLAGS_GET_Z(icurve->points->flags), FLAGS_GET_M(icurve->points->flags), 64);	for (i = 2; i < icurve->points->npoints; i+=2)	{		LWDEBUGF(3, "lwcircstring_segmentize: arc ending at point %d", i);		getPoint4d_p(icurve->points, i - 2, &p1);		getPoint4d_p(icurve->points, i - 1, &p2);		getPoint4d_p(icurve->points, i, &p3);		tmp = lwcircle_segmentize(&p1, &p2, &p3, perQuad);		if (tmp)		{			LWDEBUGF(3, "lwcircstring_segmentize: generated %d points", tmp->npoints);			for (j = 0; j < tmp->npoints; j++)			{				getPoint4d_p(tmp, j, &p4);				ptarray_append_point(ptarray, &p4, LW_TRUE);			}			ptarray_free(tmp);		}		else		{			LWDEBUG(3, "lwcircstring_segmentize: points are colinear, returning curve points as line");			for (j = i - 1 ; j <= i ; j++)			{				getPoint4d_p(icurve->points, j, &p4);				ptarray_append_point(ptarray, &p4, LW_TRUE);			}		}	}	getPoint4d_p(icurve->points, icurve->points->npoints-1, &p1);	ptarray_append_point(ptarray, &p1, LW_TRUE);			oline = lwline_construct(icurve->srid, NULL, ptarray);	return oline;}

/* * 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. * */POINTARRAY *ptarray_grid(const POINTARRAY *pa, const gridspec *grid){	POINT4D pt;	int ipn; /* input point numbers */	POINTARRAY *dpa;	LWDEBUGF(2, "ptarray_grid called on %p", pa);	dpa = ptarray_construct_empty(FLAGS_GET_Z(pa->flags),FLAGS_GET_M(pa->flags), pa->npoints);	for (ipn=0; ipn<pa->npoints; ++ipn)	{		getPoint4d_p(pa, ipn, &pt);		if ( grid->xsize )			pt.x = rint((pt.x - grid->ipx)/grid->xsize) *			         grid->xsize + grid->ipx;		if ( grid->ysize )			pt.y = rint((pt.y - grid->ipy)/grid->ysize) *			         grid->ysize + grid->ipy;		if ( FLAGS_GET_Z(pa->flags) && grid->zsize )			pt.z = rint((pt.z - grid->ipz)/grid->zsize) *			         grid->zsize + grid->ipz;		if ( FLAGS_GET_M(pa->flags) && grid->msize )			pt.m = rint((pt.m - grid->ipm)/grid->msize) *			         grid->msize + grid->ipm;		ptarray_append_point(dpa, &pt, LW_FALSE);	}	return dpa;}

/* * 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. * */POINTARRAY *ptarray_grid(POINTARRAY *pa, gridspec *grid){	POINT4D pbuf;	int ipn, opn; /* point numbers (input/output) */	POINTARRAY *dpa;	POSTGIS_DEBUGF(2, "ptarray_grid called on %p", pa);	dpa = ptarray_construct_empty(FLAGS_GET_Z(pa->flags),FLAGS_GET_M(pa->flags), pa->npoints);	for (ipn=0, opn=0; ipn<pa->npoints; ++ipn)	{		getPoint4d_p(pa, ipn, &pbuf);		if ( grid->xsize )			pbuf.x = rint((pbuf.x - grid->ipx)/grid->xsize) *			         grid->xsize + grid->ipx;		if ( grid->ysize )			pbuf.y = rint((pbuf.y - grid->ipy)/grid->ysize) *			         grid->ysize + grid->ipy;		if ( FLAGS_GET_Z(pa->flags) && grid->zsize )			pbuf.z = rint((pbuf.z - grid->ipz)/grid->zsize) *			         grid->zsize + grid->ipz;		if ( FLAGS_GET_M(pa->flags) && grid->msize )			pbuf.m = rint((pbuf.m - grid->ipm)/grid->msize) *			         grid->msize + grid->ipm;		ptarray_append_point(dpa, &pbuf, LW_FALSE);	}	return dpa;}