postgis/liblwgeom/liblwgeom_internal.h

/**********************************************************************
 * $Id: liblwgeom_internal.h 4497 2009-09-14 18:33:54Z pramsey $
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.refractions.net
 * Copyright 2001-2006 Refractions Research Inc.
 * Copyright 2007-2008 Mark Cave-Ayland
 * Copyright 2008 Paul Ramsey <pramsey@cleverelephant.ca>
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU General Public Licence. See the COPYING file.
 *
 **********************************************************************/

#include <assert.h>
#include "liblwgeom.h"
#include <string.h>
#include <math.h>
#include <inttypes.h>
#if HAVE_IEEEFP_H
#include <ieeefp.h>
#endif

#ifndef _LIBLWGEOM_INTERNAL_H
#define _LIBLWGEOM_INTERNAL_H 1

/**
* PI
*/
#define PI 3.1415926535897932384626433832795

/**
* Floating point comparitors.
*/
#define FP_TOLERANCE 1e-12
#define FP_IS_ZERO(A) (fabs(A) <= FP_TOLERANCE)
#define FP_MAX(A, B) (((A) > (B)) ? (A) : (B))
#define FP_MIN(A, B) (((A) < (B)) ? (A) : (B))
#define FP_EQUALS(A, B) (fabs((A)-(B)) <= FP_TOLERANCE)
#define FP_NEQUALS(A, B) (fabs((A)-(B)) > FP_TOLERANCE)
#define FP_LT(A, B) (((A) + FP_TOLERANCE) < (B))
#define FP_LTEQ(A, B) (((A) - FP_TOLERANCE) <= (B))
#define FP_GT(A, B) (((A) - FP_TOLERANCE) > (B))
#define FP_GTEQ(A, B) (((A) + FP_TOLERANCE) >= (B))
#define FP_CONTAINS_TOP(A, X, B) (FP_LT(A, X) && FP_LTEQ(X, B))
#define FP_CONTAINS_BOTTOM(A, X, B) (FP_LTEQ(A, X) && FP_LT(X, B))
#define FP_CONTAINS_INCL(A, X, B) (FP_LTEQ(A, X) && FP_LTEQ(X, B))
#define FP_CONTAINS_EXCL(A, X, B) (FP_LT(A, X) && FP_LT(X, B))
#define FP_CONTAINS(A, X, B) FP_CONTAINS_EXCL(A, X, B)

/**
* Largest float value. Should this be from math.h instead?
*/
#ifndef MAXFLOAT
#define MAXFLOAT      3.402823466e+38F
#endif


/**
* Well-Known Text (WKT) Output Variant Types
*/
#define WKT_NO_TYPE 0x08 /* Internal use only */
#define WKT_NO_PARENS 0x10 /* Internal use only */
#define WKT_IS_CHILD 0x20 /* Internal use only */

/**
* Well-Known Binary (WKB) Output Variant Types
*/

#define WKB_DOUBLE_SIZE 8 /* Internal use only */
#define WKB_INT_SIZE 4 /* Internal use only */
#define WKB_BYTE_SIZE 1 /* Internal use only */

/**
* Well-Known Binary (WKB) Geometry Types 
*/
#define WKB_POINT_TYPE 1
#define WKB_LINESTRING_TYPE 2
#define WKB_POLYGON_TYPE 3
#define WKB_MULTIPOINT_TYPE 4
#define WKB_MULTILINESTRING_TYPE 5
#define WKB_MULTIPOLYGON_TYPE 6
#define WKB_GEOMETRYCOLLECTION_TYPE 7
#define WKB_CIRCULARSTRING_TYPE 8
#define WKB_COMPOUNDCURVE_TYPE 9
#define WKB_CURVEPOLYGON_TYPE 10
#define WKB_MULTICURVE_TYPE 11
#define WKB_MULTISURFACE_TYPE 12
#define WKB_CURVE_TYPE 13 /* from ISO draft, not sure is real */
#define WKB_SURFACE_TYPE 14 /* from ISO draft, not sure is real */
#define WKB_POLYHEDRALSURFACE_TYPE 15
#define WKB_TIN_TYPE 16
#define WKB_TRIANGLE_TYPE 17

/**
* Macro for reading the size from the GSERIALIZED size attribute.
* Cribbed from PgSQL, top 30 bits are size. Use VARSIZE() when working
* internally with PgSQL.
*/
#define SIZE_GET(varsize) (((varsize) >> 2) & 0x3FFFFFFF)
#define SIZE_SET(varsize, size) (((varsize) & 0x00000003)|(((size) & 0x3FFFFFFF) << 2 ))


/*
* Internal prototypes
*/


/* Machine endianness */
#define XDR 0
#define NDR 1
extern char getMachineEndian(void);

/* Raise an lwerror if srids do not match */
void error_if_srid_mismatch(int srid1, int srid2);


/*
* Force dims
*/
LWGEOM* lwgeom_force_dims(const LWGEOM *lwgeom, int hasz, int hasm);
LWPOINT* lwpoint_force_dims(const LWPOINT *lwpoint, int hasz, int hasm);
LWLINE* lwline_force_dims(const LWLINE *lwline, int hasz, int hasm);
LWPOLY* lwpoly_force_dims(const LWPOLY *lwpoly, int hasz, int hasm);
LWCOLLECTION* lwcollection_force_dims(const LWCOLLECTION *lwcol, int hasz, int hasm);
POINTARRAY* ptarray_force_dims(const POINTARRAY *pa, int hasz, int hasm);

/*
* Is Empty?
*/
int lwpoly_is_empty(const LWPOLY *poly);
int lwcollection_is_empty(const LWCOLLECTION *col);
int lwcircstring_is_empty(const LWCIRCSTRING *circ);
int lwtriangle_is_empty(const LWTRIANGLE *triangle);
int lwline_is_empty(const LWLINE *line);
int lwpoint_is_empty(const LWPOINT *point);

/*
* Number of vertices?
*/
int lwline_count_vertices(LWLINE *line);
int lwpoly_count_vertices(LWPOLY *poly);
int lwcollection_count_vertices(LWCOLLECTION *col);

/*
* DP simplification
*/
POINTARRAY* ptarray_simplify(POINTARRAY *inpts, double epsilon);
LWLINE* lwline_simplify(const LWLINE *iline, double dist);
LWPOLY* lwpoly_simplify(const LWPOLY *ipoly, double dist);
LWCOLLECTION* lwcollection_simplify(const LWCOLLECTION *igeom, double dist);

/*
* Computational geometry
*/
int signum(double n);

/*
* The possible ways a pair of segments can interact. Returned by lw_segment_intersects 
*/
enum CG_SEGMENT_INTERSECTION_TYPE {
    SEG_ERROR = -1,
    SEG_NO_INTERSECTION = 0,
    SEG_COLINEAR = 1,
    SEG_CROSS_LEFT = 2,
    SEG_CROSS_RIGHT = 3,
    SEG_TOUCH_LEFT = 4,
    SEG_TOUCH_RIGHT = 5
};

/*
* Do the segments intersect? How?
*/
int lw_segment_intersects(const POINT2D *p1, const POINT2D *p2, const POINT2D *q1, const POINT2D *q2);

/*
* What side of the line formed by p1 and p2 does q fall? 
* Returns < 0 for left and > 0 for right and 0 for co-linearity
*/
double lw_segment_side(const POINT2D *p1, const POINT2D *p2, const POINT2D *q);

/* 
* Do the envelopes of the the segments intersect?
*/
int lw_segment_envelope_intersects(const POINT2D *p1, const POINT2D *p2, const POINT2D *q1, const POINT2D *q2);

/*
* Get/Set an enumeratoed ordinate. (x,y,z,m)
*/
double lwpoint_get_ordinate(const POINT4D *p, int ordinate);
void lwpoint_set_ordinate(POINT4D *p, int ordinate, double value);

/* 
* Generate an interpolated coordinate p given an interpolation value and ordinate to apply it to
*/
int lwpoint_interpolate(const POINT4D *p1, const POINT4D *p2, POINT4D *p, int ndims, int ordinate, double interpolation_value);

/*
* Geohash
*/
int lwgeom_geohash_precision(GBOX bbox, GBOX *bounds);
char *geohash_point(double longitude, double latitude, int precision);

/*
* Point comparisons
*/
int p4d_same(POINT4D p1, POINT4D p2);

/*
* Area calculations
*/
double lwpoly_area(const LWPOLY *poly);
double lwcurvepoly_area(const LWCURVEPOLY *curvepoly);
double lwtriangle_area(const LWTRIANGLE *triangle);

/*
* Length calculations
*/
double lwcompound_length(const LWCOMPOUND *comp);
double lwcompound_length_2d(const LWCOMPOUND *comp);
double lwline_length(const LWLINE *line);
double lwline_length_2d(const LWLINE *line);
double lwcircstring_length(const LWCIRCSTRING *circ);
double lwcircstring_length_2d(const LWCIRCSTRING *circ);
double lwpoly_perimeter(const LWPOLY *poly);
double lwpoly_perimeter_2d(const LWPOLY *poly);
double lwcurvepoly_perimeter(const LWCURVEPOLY *poly);
double lwcurvepoly_perimeter_2d(const LWCURVEPOLY *poly);
double lwtriangle_perimeter(const LWTRIANGLE *triangle);
double lwtriangle_perimeter_2d(const LWTRIANGLE *triangle);

/*
* Segmentization
*/
LWLINE *lwcircstring_segmentize(const LWCIRCSTRING *icurve, uint32 perQuad);
LWLINE *lwcompound_segmentize(const LWCOMPOUND *icompound, uint32 perQuad);
LWPOLY *lwcurvepoly_segmentize(const LWCURVEPOLY *curvepoly, uint32 perQuad);

/*
* Affine
*/
void ptarray_affine(POINTARRAY *pa, const AFFINE *affine);

/*
* PointArray
*/
char ptarray_isccw(const POINTARRAY *pa);


#endif /* _LIBLWGEOM_INTERNAL_H */