+++ /dev/null
-//lwgeom.h
-
-// basic API for handling the LWGEOM, BOX2DFLOAT4, LWPOINT, LWLINE, and LWPOLY.
-// See below for other support types like POINTARRAY and LWGEOM_INSPECTED
-
-
-typedef struct
-{
- float xmin;
- float ymin;
- float xmax;
- float ymax;
-} BOX2DFLOAT4;
-
-
-// POINT3D already defined in postgis.h
-// ALL LWGEOM structures will use POINT3D as an abstract point.
-// This means a 2d geometry will be stored as (x,y) in its serialized
-// form, but all functions will work on (x,y,0). This keeps all the
-// analysis functions simple.
-// NOTE: for GEOS integration, we'll probably set z=NaN
-// so look out - z might be NaN for 2d geometries!
-
-// typedef struct { double x,y,z; } POINT3D;
-
-
-// type for 2d points. When you convert this to 3d, the
-// z component will be either 0 or NaN.
-typedef struct
-{
- double x;
- double y;
-} POINT2D;
-
-
-// Point array abstracts a lot of the complexity of points and point lists.
-// It handles miss-alignment in the serialized form, 2d/3d translation
-// (2d points converted to 3d will have z=0 or NaN)
-
-typedef struct
-{
- char *serialized_pointlist; // probably missaligned. 2d or 3d. points to a double
- char is3d; // true if these are 3d points
- int32 npoints;
-} POINTARRAY;
-
-// copies a point from the point array into the parameter point
-// will set point's z=0 (or NaN) if pa is 2d
-// NOTE: point is a real POINT3D *not* a pointer
-extern POINT3D getPoint3d(POINTARRAY pa, int n);
-
-// copies a point from the point array into the parameter point
-// will set point's z=0 (or NaN) if pa is 2d
-// NOTE: this will modify the point3d pointed to by 'point'.
-extern void getPoint3d_p(POINTARRAY pa, int n, POINT3D *point);
-
-
-// copies a point from the point array into the parameter point
-// z value (if present is not returned)
-// NOTE: point is a real POINT3D *not* a pointer
-extern POINT2D getPoint2d(POINTARRAY pa, int n);
-
-// copies a point from the point array into the parameter point
-// z value (if present is not returned)
-// NOTE: this will modify the point2d pointed to by 'point'.
-extern void getPoint2d_p(POINTARRAY pa, int n, POINT2D *point);
-
-
-// constructs a POINTARRAY.
-// NOTE: points is *not* copied, so be careful about modification (can be aligned/missaligned)
-// NOTE: is3d is descriptive - it describes what type of data 'points'
-// points to. No data conversion is done.
-extern POINTARRAY pointArray_construct(char *points, char is3d, int npoints);
-
-
-/*
-
- LWGEOM types are an 8-bit char in this format:
-
-xxSDtttt
-
-WHERE
- x = unused
- S = 4 byte SRID attached (0= not attached (-1), 1= attached)
- D = dimentionality (0=2d, 1=3d)
- tttt = actual type (as per the WKB type):
-
- enum wkbGeometryType {
- wkbPoint = 1,
- wkbLineString = 2,
- wkbPolygon = 3,
- wkbMultiPoint = 4,
- wkbMultiLineString = 5,
- wkbMultiPolygon = 6,
- wkbGeometryCollection = 7
- };
-
-*/
-
-
-/* already defined in postgis.h
-
- #define POINTTYPE 1
- #define LINETYPE 2
- #define POLYGONTYPE 3
- #define MULTIPOINTTYPE 4
- #define MULTILINETYPE 5
- #define MULTIPOLYGONTYPE 6
- #define COLLECTIONTYPE 7
-
-*/
-
-
-extern bool lwgeom_hasSRID(char type); // true iff S bit is set
-extern bool lwgeom_is3d(char type); // true iff D bit is set
-extern int lwgeom_getType(char type); // returns the tttt value
-
-
-
-// all the base types (point/line/polygon) will have a
-// basic constructor, basic de-serializer, basic serializer, and
-// bounding box finder.
-
-
-
-//--------------------------------------------------------
-
-typedef struct
-{
- char is3d; // true means points represent 3d points
- int SRID; // spatial ref sys -1=none
- POINTARRAY *points; // array of POINT3D
-} LWLINE; //"light-weight line"
-
-// construct a new LWLINE. points will be copied
-// use SRID=-1 for unknown SRID (will have 8bit type's S = 0)
-extern LWLINE lwline_construct(char is3d, int SRID, int npoints, POINTARRAY *points);
-
-// given the LWGEOM serialized form (or a pointer into a muli* one)
-// construct a proper LWLINE.
-// serialized_form should point to the 8bit type format (with type = 2)
-// See serialized form doc
-extern LWLINE lwline_deserialize(char *serialized_form);
-
-// convert this line into its serialize form
-// result's first char will be the 8bit type. See serialized form doc
-extern char *lwline_serialize(LWLINE *line);
-
-// find bounding box (standard one) zmin=zmax=0 if 2d (might change to NaN)
-extern BOX3D *lwline_findbbox(LWLINE *line);
-
-
-//--------------------------------------------------------
-
-typedef struct
-{
- char is3d; // true means points represent 3d points
- int SRID; // spatial ref sys
- POINTARRAY *point; // hide 2d/3d (this will be an array of 1 point)
-} LWPOINT; // "light-weight point"
-
-// construct a new point. point will be copied
-// use SRID=-1 for unknown SRID (will have 8bit type's S = 0)
-extern LWPOINT lwpoint_construct(char is3d, int SRID, POINT3D *point);
-
-// given the LWPOINT serialized form (or a pointer into a muli* one)
-// construct a proper LWPOINT.
-// serialized_form should point to the 8bit type format (with type = 1)
-// See serialized form doc
-extern LWPOINT lwpoint_deserialize(char *serialized_form);
-
-// convert this line into its serialize form
-// result's first char will be the 8bit type. See serialized form doc
-extern char *lwpoint_serialize(LWPOINT *point);
-
-// find bounding box (standard one) zmin=zmax=0 if 2d (might change to NaN)
-extern BOX3D *lwpoint_findbbox(LWPOINT *point);
-
-// convenience functions to hide the POINTARRAY
-extern POINT2D lwpoint_getPoint2d(LWPOINT *point);
-extern POINT3D lwpoint_getPoint3d(LWPOINT *point);
-
-//--------------------------------------------------------
-
-
-typedef struct
-{
- char is3d;
- int SRID;
- int nrings;
- POINTARRAY **rings; // list of rings (list of points)
-} LWPOLY; // "light-weight polygon"
-
-// construct a new LWLINE. arrays (points/points per ring) will NOT be copied
-// use SRID=-1 for unknown SRID (will have 8bit type's S = 0)
-extern LWLINE lwpoly_construct(char is3d, int SRID, int nrings,POINTARRAY **points);
-
-
-// given the LWPOLY serialized form (or a pointer into a muli* one)
-// construct a proper LWPOLY.
-// serialized_form should point to the 8bit type format (with type = 3)
-// See serialized form doc
-extern LWPOLY lwpoly_deserialize(char *serialized_form);
-
-// find bounding box (standard one) zmin=zmax=0 if 2d (might change to NaN)
-extern BOX3D *lwpoly_findbbox(LWPOLY *line);
-
-
-
-//------------------------------------------------------
-// Multi-geometries
-
-// These are all handled equivelently so its easy to write iterator code.
-// NOTE NOTE: you can hand in a non-multigeometry to most of these functions
-// and get usual behavior (ie. get geometry 0 on a POINT will return the
-// point). This makes coding even easier since you dont have to necessarily
-// differenciate between the multi* and non-multi geometries.
-//
-// NOTE: these usually work directly off the serialized form, so they're a little more
-// difficult to handle (and slower)
-// NOTE NOTE: the get functions maybe slow, so we may want to have an "analysed"
-// lwgeom that would just have pointer to the start of each sub-geometry.
-
-
-
-// use this version for speed. READ-ONLY!
-typedef struct
-{
- char *serialized_form; // orginal structure
- char type; // 8-bit type for the LWGEOM
- int ngeometries; // number of sub-geometries
- char **sub_geoms; // list of pointers (into serialized_form) of the sub-geoms
-} LWGEOM_INSPECTED;
-
-// note - for a simple type (ie. point), this will have sub_geom[0] = serialized_form.
-// for multi-geomtries sub_geom[0] will be a few bytes into the serialized form
-// This function just computes the length of each sub-object and pre-caches this info.
-// For a geometry collection of multi* geometries, you can inspect the sub-components
-// as well.
-extern LWGEOM_INSPECTED lwgeom_inspect(char *serialized_form);
-
-
-// 1st geometry has geom_number = 0
-// if the actual sub-geometry isnt a POINT, null is returned (see _gettype()).
-// if there arent enough geometries, return null.
-// this is fine to call on a point (with geom_num=0), multipoint or geometrycollection
-extern LWPOINT lwgeom_getpoint(char *serialized_form, int geom_number);
-extern LWPOINT lwgeom_getpoint_inspected(LWGEOM_INSPECTED *inspected, int geom_number);
-
-// 1st geometry has geom_number = 0
-// if the actual geometry isnt a LINE, null is returned (see _gettype()).
-// if there arent enough geometries, return null.
-// this is fine to call on a line, multiline or geometrycollection
-extern LWLINE lwgeom_getline(char *serialized_form, int geom_number);
-extern LWLINE lwgeom_getline_inspected(LWGEOM_INSPECTED *inspected, int geom_number);
-
-// 1st geometry has geom_number = 0
-// if the actual geometry isnt a POLYGON, null is returned (see _gettype()).
-// if there arent enough geometries, return null.
-// this is fine to call on a polygon, multipolygon or geometrycollection
-extern LWPOLY lwgeom_getpoly(char *serialized_form, int geom_number);
-extern LWPOLY lwgeom_getpoly_inspected(LWGEOM_INSPECTED *inspected, int geom_number);
-
-// this gets the serialized form of a sub-geometry
-// 1st geometry has geom_number = 0
-// if this isnt a multi* geometry, and geom_number ==0 then it returns
-// itself
-// returns null on problems.
-// in the future this is how you would access a muli* portion of a
-// geometry collection.
-// GEOMETRYCOLLECTION(MULTIPOINT(0 0, 1 1), LINESTRING(0 0, 1 1))
-// ie. lwgeom_getpoint( lwgeom_getsubgeometry( serialized, 0), 1)
-// --> POINT(1 1)
-// you can inspect the sub-geometry as well if you wish.
-extern char *lwgeom_getsubgeometry(char *serialized_form, int geom_number);
-extern char *lwgeom_getsubgeometry_inspected(LWGEOM_INSPECTED *inspected, int geom_number);
-
-
-// 1st geometry has geom_number = 0
-// use geom_number = -1 to find the actual type of the serialized form.
-// ie lwgeom_gettype( <'MULTIPOINT(0 0, 1 1)'>, -1)
-// --> multipoint
-// ie lwgeom_gettype( <'MULTIPOINT(0 0, 1 1)'>, 0)
-// --> point
-// gets the 8bit type of the geometry at location geom_number
-extern char lwgeom_gettype(char *serialized_form, int geom_number);
-extern char lwgeom_gettype_inspected(LWGEOM_INSPECTED *inspected, int geom_number);
-
-
-// how many sub-geometries are there?
-// for point,line,polygon will return 1.
-extern int lwgeom_getnumgeometries(char *serialized_form);
-extern int lwgeom_getnumgeometries_inspected(LWGEOM_INSPECTED *inspected);
-
-
-// set finalType to 0 and this will choose an appropriate type
-// if you specify a wrong type, the best type will be chosen
-// (ie. give it 2 points and ask it to be a multilinestring)
-// use SRID=-1 for unknown SRID (will have 8bit type's S = 0)
-// all subgeometries must have the same SRID
-// if you want to construct an inspected, call this then inspect the result...
-extern char *lwgeom_construct(int SRID,int finalType, int nsubgeometries, char **serialized_subs);
-
-
-// construct the empty geometry (GEOMETRYCOLLECTION(EMPTY))
-extern char *lwgeom_constructempty();
-
-// helper function (not for general use)
-// find the size a geometry (or a sub-geometry)
-// 1st geometry has geom_number = 0
-// use geom_number = -1 to find the actual type of the serialized form.
-// ie lwgeom_gettype( <'MULTIPOINT(0 0, 1 1)'>, -1)
-// --> size of the multipoint
-// ie lwgeom_gettype( <'MULTIPOINT(0 0, 1 1)'>, 0)
-// --> size of the point
-extern int lwgeom_seralizedformlength(char *serialized_form, int geom_number);
-extern int lwgeom_seralizedformlength_inspected(LWGEOM_INSPECTED *inspected, int geom_number);
-
-
-//get bounding box of LWGEOM (automatically calls the sub-geometries bbox generators)
-extern BOX3D lw_geom_getBB(char *serialized_form);
-extern BOX3D lw_geom_getBB_inspected(LWGEOM_INSPECTED *inspected);
-
-
-//------------------------------------------------------
-// other stuff
-
-// handle the double-to-float conversion. The results of this
-// will usually be a slightly bigger box because of the difference
-// between float8 and float4 representations.
-
-extern BOX2DFLOAT4 box3d_to_box2df(BOX3D *box);
-extern BOX2DFLOAT4 box_to_box2df(BOX *box); // postgresql standard type
-
-extern BOX3D box2df_to_box3d(BOX2DFLOAT4 *box);
-extern BOX box2df_to_box(BOX *box); // postgresql standard type
-
-
-
-//------------------------------------------------------------
-//------------------------------------------------------------
-// On serialized form (see top for the 8bit type implementation)
-
-// NOTE: contrary to the original proposal, bounding boxes are *never*
-// included in the geometry. You must either refer to the index
-// or compute it on demand.
-
-
-// The serialized form is always a stream of bytes. The first four are always
-// the memory size of the LWGEOM (including the 4 byte memory size).
-
-// The easiest way to describe the serialed form is with examples:
-
-//3D point w/o bounding box::
-//<int32> size = 29 bytes
-//<char> type: S=0,D=1, tttt= 1
-//<double> X
-//<double> Y
-//<double> Z
-
-//2D line String
-//<int32> size = ...
-//<char> type: S=0,D=0, tttt= 2
-//<uint32> npoints
-//<double> X0
-//<double> Y0
-//<double> X1
-//<double> Y1
-//<double> X2
-//<double> Y2
-//...
-
-//3D polygon w/o bounding box
-//<int32> size = ...
-//<char> type: S=0,D=0, tttt= 3
-//<uint32> nrings
-//<uint32> npoints in ring0
-//<double> X0
-//<double> Y0
-//<double> X1
-//<double> Y1
-//<double> X2
-//<double> Y2
-//...
-//<uint32> npoints in ring1
-//<double> X0
-//<double> Y0
-//<double> X1
-//<double> Y1
-//<double> X2
-//<double> Y2
-//...
-//...
-
-
-// the multi* representations are very simple
-
-//<int32> size = ...
-//<char> type: ... with tttt= <multi* or geometrycollection>
-//<int32> ngeometries
-// <geometry zero, serialized form>
-// <geometry one, serialized form>
-// <geometry two, serialzied form>
-// ...
-
-
-
-// see implementation for more exact details.
-
-
-//----------------------------------------------------------------
-// example function (computes total length of the lines in a LWGEOM).
-// This works for a LINESTRING, MULTILINESTRING, OR GEOMETRYCOLLECTION
-
-
-
-// char *serialized_form = (char *) [[get from database]]
-//
-// double total_length_so_far = 0;
-// for (int t=0;t< lwgeom_getnumgeometries(serialized_form) ; t++)
-// {
-// LWLINE *line = lwgeom_getline(serialized_form, t);
-// if (line != NULL)
-// {
-// double length = findlength( POINT_ARRAY(line->points) ); //2d/3d aware
-// total_length_so_far + = length;
-// }
-// }
-// return total_length_so_far;
-
-
-// using the LWGEOM_INSPECTED way:
-
-
-// char *serialized_form = (char *) [[get from datbase]]
-// LWGEOM_INSPECTED inspected_geom = lwgeom_inspect(serialized_form);
-//
-// double total_length_so_far = 0;
-// for (int t=0;t< lwgeom_getnumgeometries(inspected_geom) ; t++)
-// {
-// LWLINE *line = lwgeom_getline(inspected_geom, t);
-// if (line != NULL)
-// {
-// double length = findlength( POINT_ARRAY(line->points) ); //2d/3d aware
-// total_length_so_far + = length;
-// }
-// }
-// return total_length_so_far;
-
-
-// the findlength() function could be written like based on functions like:
-//
-// POINT3D getPoint3d(POINTARRAY pa, int n); (for a 2d/3d point and 3d length)
-// POINT2D getPoint2d(POINTARRAY pa, int n); (for a 2d/3d point and 2d length)
-// NOTE: make sure your findlength() function knows what to do with z=NaN.
-
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