1 /*-------------------------------------------------------------------------
2 *
3 * geo_decls.h - Declarations for various 2D constructs.
4 *
5 *
6 * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 * src/include/utils/geo_decls.h
10 *
11 * XXX These routines were not written by a numerical analyst.
12 *
13 * XXX I have made some attempt to flesh out the operators
14 * and data types. There are still some more to do. - tgl 97/04/19
15 *
16 *-------------------------------------------------------------------------
17 */
18 #ifndef GEO_DECLS_H
19 #define GEO_DECLS_H
20
21 #include <math.h>
22
23 #include "fmgr.h"
24
25 /*--------------------------------------------------------------------
26 * Useful floating point utilities and constants.
27 *--------------------------------------------------------------------
28 *
29 * "Fuzzy" floating-point comparisons: values within EPSILON of each other
30 * are considered equal. Beware of normal reasoning about the behavior of
31 * these comparisons, since for example FPeq does not behave transitively.
32 *
33 * Note that these functions are not NaN-aware and will give FALSE for
34 * any case involving NaN inputs.
35 *
36 * Also note that these will give sane answers for infinite inputs,
37 * where it's important to avoid computing Inf minus Inf; we do so
38 * by eliminating equality cases before subtracting.
39 */
40
41 #define EPSILON 1.0E-06
42
43 #ifdef EPSILON
44 #define FPzero(A) (fabs(A) <= EPSILON)
45
46 static inline bool
FPeq(double A,double B)47 FPeq(double A, double B)
48 {
49 return A == B || fabs(A - B) <= EPSILON;
50 }
51
52 static inline bool
FPne(double A,double B)53 FPne(double A, double B)
54 {
55 return A != B && fabs(A - B) > EPSILON;
56 }
57
58 static inline bool
FPlt(double A,double B)59 FPlt(double A, double B)
60 {
61 return A + EPSILON < B;
62 }
63
64 static inline bool
FPle(double A,double B)65 FPle(double A, double B)
66 {
67 return A <= B + EPSILON;
68 }
69
70 static inline bool
FPgt(double A,double B)71 FPgt(double A, double B)
72 {
73 return A > B + EPSILON;
74 }
75
76 static inline bool
FPge(double A,double B)77 FPge(double A, double B)
78 {
79 return A + EPSILON >= B;
80 }
81 #else
82 #define FPzero(A) ((A) == 0)
83 #define FPeq(A,B) ((A) == (B))
84 #define FPne(A,B) ((A) != (B))
85 #define FPlt(A,B) ((A) < (B))
86 #define FPle(A,B) ((A) <= (B))
87 #define FPgt(A,B) ((A) > (B))
88 #define FPge(A,B) ((A) >= (B))
89 #endif
90
91 #define HYPOT(A, B) pg_hypot(A, B)
92
93 /*---------------------------------------------------------------------
94 * Point - (x,y)
95 *-------------------------------------------------------------------*/
96 typedef struct
97 {
98 float8 x,
99 y;
100 } Point;
101
102
103 /*---------------------------------------------------------------------
104 * LSEG - A straight line, specified by endpoints.
105 *-------------------------------------------------------------------*/
106 typedef struct
107 {
108 Point p[2];
109 } LSEG;
110
111
112 /*---------------------------------------------------------------------
113 * PATH - Specified by vertex points.
114 *-------------------------------------------------------------------*/
115 typedef struct
116 {
117 int32 vl_len_; /* varlena header (do not touch directly!) */
118 int32 npts;
119 int32 closed; /* is this a closed polygon? */
120 int32 dummy; /* padding to make it double align */
121 Point p[FLEXIBLE_ARRAY_MEMBER];
122 } PATH;
123
124
125 /*---------------------------------------------------------------------
126 * LINE - Specified by its general equation (Ax+By+C=0).
127 *-------------------------------------------------------------------*/
128 typedef struct
129 {
130 float8 A,
131 B,
132 C;
133 } LINE;
134
135
136 /*---------------------------------------------------------------------
137 * BOX - Specified by two corner points, which are
138 * sorted to save calculation time later.
139 *-------------------------------------------------------------------*/
140 typedef struct
141 {
142 Point high,
143 low; /* corner POINTs */
144 } BOX;
145
146 /*---------------------------------------------------------------------
147 * POLYGON - Specified by an array of doubles defining the points,
148 * keeping the number of points and the bounding box for
149 * speed purposes.
150 *-------------------------------------------------------------------*/
151 typedef struct
152 {
153 int32 vl_len_; /* varlena header (do not touch directly!) */
154 int32 npts;
155 BOX boundbox;
156 Point p[FLEXIBLE_ARRAY_MEMBER];
157 } POLYGON;
158
159 /*---------------------------------------------------------------------
160 * CIRCLE - Specified by a center point and radius.
161 *-------------------------------------------------------------------*/
162 typedef struct
163 {
164 Point center;
165 float8 radius;
166 } CIRCLE;
167
168 /*
169 * fmgr interface macros
170 *
171 * Path and Polygon are toastable varlena types, the others are just
172 * fixed-size pass-by-reference types.
173 */
174
175 #define DatumGetPointP(X) ((Point *) DatumGetPointer(X))
176 #define PointPGetDatum(X) PointerGetDatum(X)
177 #define PG_GETARG_POINT_P(n) DatumGetPointP(PG_GETARG_DATUM(n))
178 #define PG_RETURN_POINT_P(x) return PointPGetDatum(x)
179
180 #define DatumGetLsegP(X) ((LSEG *) DatumGetPointer(X))
181 #define LsegPGetDatum(X) PointerGetDatum(X)
182 #define PG_GETARG_LSEG_P(n) DatumGetLsegP(PG_GETARG_DATUM(n))
183 #define PG_RETURN_LSEG_P(x) return LsegPGetDatum(x)
184
185 #define DatumGetPathP(X) ((PATH *) PG_DETOAST_DATUM(X))
186 #define DatumGetPathPCopy(X) ((PATH *) PG_DETOAST_DATUM_COPY(X))
187 #define PathPGetDatum(X) PointerGetDatum(X)
188 #define PG_GETARG_PATH_P(n) DatumGetPathP(PG_GETARG_DATUM(n))
189 #define PG_GETARG_PATH_P_COPY(n) DatumGetPathPCopy(PG_GETARG_DATUM(n))
190 #define PG_RETURN_PATH_P(x) return PathPGetDatum(x)
191
192 #define DatumGetLineP(X) ((LINE *) DatumGetPointer(X))
193 #define LinePGetDatum(X) PointerGetDatum(X)
194 #define PG_GETARG_LINE_P(n) DatumGetLineP(PG_GETARG_DATUM(n))
195 #define PG_RETURN_LINE_P(x) return LinePGetDatum(x)
196
197 #define DatumGetBoxP(X) ((BOX *) DatumGetPointer(X))
198 #define BoxPGetDatum(X) PointerGetDatum(X)
199 #define PG_GETARG_BOX_P(n) DatumGetBoxP(PG_GETARG_DATUM(n))
200 #define PG_RETURN_BOX_P(x) return BoxPGetDatum(x)
201
202 #define DatumGetPolygonP(X) ((POLYGON *) PG_DETOAST_DATUM(X))
203 #define DatumGetPolygonPCopy(X) ((POLYGON *) PG_DETOAST_DATUM_COPY(X))
204 #define PolygonPGetDatum(X) PointerGetDatum(X)
205 #define PG_GETARG_POLYGON_P(n) DatumGetPolygonP(PG_GETARG_DATUM(n))
206 #define PG_GETARG_POLYGON_P_COPY(n) DatumGetPolygonPCopy(PG_GETARG_DATUM(n))
207 #define PG_RETURN_POLYGON_P(x) return PolygonPGetDatum(x)
208
209 #define DatumGetCircleP(X) ((CIRCLE *) DatumGetPointer(X))
210 #define CirclePGetDatum(X) PointerGetDatum(X)
211 #define PG_GETARG_CIRCLE_P(n) DatumGetCircleP(PG_GETARG_DATUM(n))
212 #define PG_RETURN_CIRCLE_P(x) return CirclePGetDatum(x)
213
214
215 /*
216 * in geo_ops.c
217 */
218
219 extern float8 pg_hypot(float8 x, float8 y);
220
221 #endif /* GEO_DECLS_H */
222