WCSLIB: prj.h Source File

WCSLIB 8.1

prj.h
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1/*============================================================================
2 WCSLIB 8.1 - an implementation of the FITS WCS standard.
3 Copyright (C) 1995-2023, Mark Calabretta
4
5 This file is part of WCSLIB.
6
7 WCSLIB is free software: you can redistribute it and/or modify it under the
8 terms of the GNU Lesser General Public License as published by the Free
9 Software Foundation, either version 3 of the License, or (at your option)
10 any later version.
11
12 WCSLIB is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15 more details.
16
17 You should have received a copy of the GNU Lesser General Public License
18 along with WCSLIB. If not, see http://www.gnu.org/licenses.
19
20 Author: Mark Calabretta, Australia Telescope National Facility, CSIRO.
21 http://www.atnf.csiro.au/people/Mark.Calabretta
22 $Id: prj.h,v 8.1 2023/07/05 17:12:07 mcalabre Exp $
23*=============================================================================
24*
25* WCSLIB 8.1 - C routines that implement the FITS World Coordinate System
26* (WCS) standard. Refer to the README file provided with WCSLIB for an
27* overview of the library.
28*
29*
30* Summary of the prj routines
31* ---------------------------
32* Routines in this suite implement the spherical map projections defined by
33* the FITS World Coordinate System (WCS) standard, as described in
34*
35= "Representations of world coordinates in FITS",
36= Greisen, E.W., & Calabretta, M.R. 2002, A&A, 395, 1061 (WCS Paper I)
37=
38= "Representations of celestial coordinates in FITS",
39= Calabretta, M.R., & Greisen, E.W. 2002, A&A, 395, 1077 (WCS Paper II)
40=
41= "Mapping on the HEALPix grid",
42= Calabretta, M.R., & Roukema, B.F. 2007, MNRAS, 381, 865 (WCS Paper V)
43=
44= "Representing the 'Butterfly' Projection in FITS -- Projection Code XPH",
45= Calabretta, M.R., & Lowe, S.R. 2013, PASA, 30, e050 (WCS Paper VI)
46*
47* These routines are based on the prjprm struct which contains all information
48* needed for the computations. The struct contains some members that must be
49* set by the user, and others that are maintained by these routines, somewhat
50* like a C++ class but with no encapsulation.
51*
52* Routine prjini() is provided to initialize the prjprm struct with default
53* values, prjfree() reclaims any memory that may have been allocated to store
54* an error message, prjsize() computes its total size including allocated
55* memory, and prjprt() prints its contents.
56*
57* prjperr() prints the error message(s) (if any) stored in a prjprm struct.
58* prjbchk() performs bounds checking on native spherical coordinates.
59*
60* Setup routines for each projection with names of the form ???set(), where
61* "???" is the down-cased three-letter projection code, compute intermediate
62* values in the prjprm struct from parameters in it that were supplied by the
63* user. The struct always needs to be set by the projection's setup routine
64* but that need not be called explicitly - refer to the explanation of
65* prjprm::flag.
66*
67* Each map projection is implemented via separate functions for the spherical
68* projection, ???s2x(), and deprojection, ???x2s().
69*
70* A set of driver routines, prjset(), prjx2s(), and prjs2x(), provides a
71* generic interface to the specific projection routines which they invoke
72* via pointers-to-functions stored in the prjprm struct.
73*
74* In summary, the routines are:
75* - prjini() Initialization routine for the prjprm struct.
76* - prjfree() Reclaim memory allocated for error messages.
77* - prjsize() Compute total size of a prjprm struct.
78* - prjprt() Print a prjprm struct.
79* - prjperr() Print error message (if any).
80* - prjbchk() Bounds checking on native coordinates.
81*
82* - prjset(), prjx2s(), prjs2x(): Generic driver routines
83*
84* - azpset(), azpx2s(), azps2x(): AZP (zenithal/azimuthal perspective)
85* - szpset(), szpx2s(), szps2x(): SZP (slant zenithal perspective)
86* - tanset(), tanx2s(), tans2x(): TAN (gnomonic)
87* - stgset(), stgx2s(), stgs2x(): STG (stereographic)
88* - sinset(), sinx2s(), sins2x(): SIN (orthographic/synthesis)
89* - arcset(), arcx2s(), arcs2x(): ARC (zenithal/azimuthal equidistant)
90* - zpnset(), zpnx2s(), zpns2x(): ZPN (zenithal/azimuthal polynomial)
91* - zeaset(), zeax2s(), zeas2x(): ZEA (zenithal/azimuthal equal area)
92* - airset(), airx2s(), airs2x(): AIR (Airy)
93* - cypset(), cypx2s(), cyps2x(): CYP (cylindrical perspective)
94* - ceaset(), ceax2s(), ceas2x(): CEA (cylindrical equal area)
95* - carset(), carx2s(), cars2x(): CAR (Plate carree)
96* - merset(), merx2s(), mers2x(): MER (Mercator)
97* - sflset(), sflx2s(), sfls2x(): SFL (Sanson-Flamsteed)
98* - parset(), parx2s(), pars2x(): PAR (parabolic)
99* - molset(), molx2s(), mols2x(): MOL (Mollweide)
100* - aitset(), aitx2s(), aits2x(): AIT (Hammer-Aitoff)
101* - copset(), copx2s(), cops2x(): COP (conic perspective)
102* - coeset(), coex2s(), coes2x(): COE (conic equal area)
103* - codset(), codx2s(), cods2x(): COD (conic equidistant)
104* - cooset(), coox2s(), coos2x(): COO (conic orthomorphic)
105* - bonset(), bonx2s(), bons2x(): BON (Bonne)
106* - pcoset(), pcox2s(), pcos2x(): PCO (polyconic)
107* - tscset(), tscx2s(), tscs2x(): TSC (tangential spherical cube)
108* - cscset(), cscx2s(), cscs2x(): CSC (COBE spherical cube)
109* - qscset(), qscx2s(), qscs2x(): QSC (quadrilateralized spherical cube)
110* - hpxset(), hpxx2s(), hpxs2x(): HPX (HEALPix)
111* - xphset(), xphx2s(), xphs2x(): XPH (HEALPix polar, aka "butterfly")
112*
113* Argument checking (projection routines):
114* ----------------------------------------
115* The values of phi and theta (the native longitude and latitude) normally lie
116* in the range [-180,180] for phi, and [-90,90] for theta. However, all
117* projection routines will accept any value of phi and will not normalize it.
118*
119* The projection routines do not explicitly check that theta lies within the
120* range [-90,90]. They do check for any value of theta that produces an
121* invalid argument to the projection equations (e.g. leading to division by
122* zero). The projection routines for AZP, SZP, TAN, SIN, ZPN, and COP also
123* return error 2 if (phi,theta) corresponds to the overlapped (far) side of
124* the projection but also return the corresponding value of (x,y). This
125* strict bounds checking may be relaxed at any time by setting
126* prjprm::bounds%2 to 0 (rather than 1); the projections need not be
127* reinitialized.
128*
129* Argument checking (deprojection routines):
130* ------------------------------------------
131* Error checking on the projected coordinates (x,y) is limited to that
132* required to ascertain whether a solution exists. Where a solution does
133* exist, an optional check is made that the value of phi and theta obtained
134* lie within the ranges [-180,180] for phi, and [-90,90] for theta. This
135* check, performed by prjbchk(), is enabled by default. It may be disabled by
136* setting prjprm::bounds%4 to 0 (rather than 1); the projections need not be
137* reinitialized.
138*
139* Accuracy:
140* ---------
141* No warranty is given for the accuracy of these routines (refer to the
142* copyright notice); intending users must satisfy for themselves their
143* adequacy for the intended purpose. However, closure to a precision of at
144* least 1E-10 degree of longitude and latitude has been verified for typical
145* projection parameters on the 1 degree graticule of native longitude and
146* latitude (to within 5 degrees of any latitude where the projection may
147* diverge). Refer to the tprj1.c and tprj2.c test routines that accompany
148* this software.
149*
150*
151* prjini() - Default constructor for the prjprm struct
152* ----------------------------------------------------
153* prjini() sets all members of a prjprm struct to default values. It should
154* be used to initialize every prjprm struct.
155*
156* PLEASE NOTE: If the prjprm struct has already been initialized, then before
157* reinitializing, it prjfree() should be used to free any memory that may have
158* been allocated to store an error message. A memory leak may otherwise
159* result.
160*
161* Returned:
162* prj struct prjprm*
163* Projection parameters.
164*
165* Function return value:
166* int Status return value:
167* 0: Success.
168* 1: Null prjprm pointer passed.
169*
170*
171* prjfree() - Destructor for the prjprm struct
172* --------------------------------------------
173* prjfree() frees any memory that may have been allocated to store an error
174* message in the prjprm struct.
175*
176* Given:
177* prj struct prjprm*
178* Projection parameters.
179*
180* Function return value:
181* int Status return value:
182* 0: Success.
183* 1: Null prjprm pointer passed.
184*
185*
186* prjsize() - Compute the size of a prjprm struct
187* -----------------------------------------------
188* prjsize() computes the full size of a prjprm struct, including allocated
189* memory.
190*
191* Given:
192* prj const struct prjprm*
193* Projection parameters.
194*
195* If NULL, the base size of the struct and the allocated
196* size are both set to zero.
197*
198* Returned:
199* sizes int[2] The first element is the base size of the struct as
200* returned by sizeof(struct prjprm). The second element
201* is the total allocated size, in bytes. This figure
202* includes memory allocated for the constituent struct,
203* prjprm::err.
204*
205* It is not an error for the struct not to have been set
206* up via prjset().
207*
208* Function return value:
209* int Status return value:
210* 0: Success.
211*
212*
213* prjprt() - Print routine for the prjprm struct
214* ----------------------------------------------
215* prjprt() prints the contents of a prjprm struct using wcsprintf(). Mainly
216* intended for diagnostic purposes.
217*
218* Given:
219* prj const struct prjprm*
220* Projection parameters.
221*
222* Function return value:
223* int Status return value:
224* 0: Success.
225* 1: Null prjprm pointer passed.
226*
227*
228* prjperr() - Print error messages from a prjprm struct
229* -----------------------------------------------------
230* prjperr() prints the error message(s) (if any) stored in a prjprm struct.
231* If there are no errors then nothing is printed. It uses wcserr_prt(), q.v.
232*
233* Given:
234* prj const struct prjprm*
235* Projection parameters.
236*
237* prefix const char *
238* If non-NULL, each output line will be prefixed with
239* this string.
240*
241* Function return value:
242* int Status return value:
243* 0: Success.
244* 1: Null prjprm pointer passed.
245*
246*
247* prjbchk() - Bounds checking on native coordinates
248* -------------------------------------------------
249* prjbchk() performs bounds checking on native spherical coordinates. As
250* returned by the deprojection (x2s) routines, native longitude is expected
251* to lie in the closed interval [-180,180], with latitude in [-90,90].
252*
253* A tolerance may be specified to provide a small allowance for numerical
254* imprecision. Values that lie outside the allowed range by not more than
255* the specified tolerance will be adjusted back into range.
256*
257* If prjprm::bounds&4 is set, as it is by prjini(), then prjbchk() will be
258* invoked automatically by the Cartesian-to-spherical deprojection (x2s)
259* routines with an appropriate tolerance set for each projection.
260*
261* Given:
262* tol double Tolerance for the bounds check [deg].
263*
264* nphi,
265* ntheta int Vector lengths.
266*
267* spt int Vector stride.
268*
269* Given and returned:
270* phi,theta double[] Native longitude and latitude (phi,theta) [deg].
271*
272* Returned:
273* stat int[] Status value for each vector element:
274* 0: Valid value of (phi,theta).
275* 1: Invalid value.
276*
277* Function return value:
278* int Status return value:
279* 0: Success.
280* 1: One or more of the (phi,theta) coordinates
281* were, invalid, as indicated by the stat vector.
282*
283*
284* prjset() - Generic setup routine for the prjprm struct
285* ------------------------------------------------------
286* prjset() sets up a prjprm struct according to information supplied within
287* it.
288*
289* Note that this routine need not be called directly; it will be invoked by
290* prjx2s() and prjs2x() if prj.flag is anything other than a predefined magic
291* value.
292*
293* The one important distinction between prjset() and the setup routines for
294* the specific projections is that the projection code must be defined in the
295* prjprm struct in order for prjset() to identify the required projection.
296* Once prjset() has initialized the prjprm struct, prjx2s() and prjs2x() use
297* the pointers to the specific projection and deprojection routines contained
298* therein.
299*
300* Given and returned:
301* prj struct prjprm*
302* Projection parameters.
303*
304* Function return value:
305* int Status return value:
306* 0: Success.
307* 1: Null prjprm pointer passed.
308* 2: Invalid projection parameters.
309*
310* For returns > 1, a detailed error message is set in
311* prjprm::err if enabled, see wcserr_enable().
312*
313*
314* prjx2s() - Generic Cartesian-to-spherical deprojection
315* ------------------------------------------------------
316* Deproject Cartesian (x,y) coordinates in the plane of projection to native
317* spherical coordinates (phi,theta).
318*
319* The projection is that specified by prjprm::code.
320*
321* Given and returned:
322* prj struct prjprm*
323* Projection parameters.
324*
325* Given:
326* nx,ny int Vector lengths.
327*
328* sxy,spt int Vector strides.
329*
330* x,y const double[]
331* Projected coordinates.
332*
333* Returned:
334* phi,theta double[] Longitude and latitude (phi,theta) of the projected
335* point in native spherical coordinates [deg].
336*
337* stat int[] Status value for each vector element:
338* 0: Success.
339* 1: Invalid value of (x,y).
340*
341* Function return value:
342* int Status return value:
343* 0: Success.
344* 1: Null prjprm pointer passed.
345* 2: Invalid projection parameters.
346* 3: One or more of the (x,y) coordinates were
347* invalid, as indicated by the stat vector.
348*
349* For returns > 1, a detailed error message is set in
350* prjprm::err if enabled, see wcserr_enable().
351*
352*
353* prjs2x() - Generic spherical-to-Cartesian projection
354* ----------------------------------------------------
355* Project native spherical coordinates (phi,theta) to Cartesian (x,y)
356* coordinates in the plane of projection.
357*
358* The projection is that specified by prjprm::code.
359*
360* Given and returned:
361* prj struct prjprm*
362* Projection parameters.
363*
364* Given:
365* nphi,
366* ntheta int Vector lengths.
367*
368* spt,sxy int Vector strides.
369*
370* phi,theta const double[]
371* Longitude and latitude (phi,theta) of the projected
372* point in native spherical coordinates [deg].
373*
374* Returned:
375* x,y double[] Projected coordinates.
376*
377* stat int[] Status value for each vector element:
378* 0: Success.
379* 1: Invalid value of (phi,theta).
380*
381* Function return value:
382* int Status return value:
383* 0: Success.
384* 1: Null prjprm pointer passed.
385* 2: Invalid projection parameters.
386* 4: One or more of the (phi,theta) coordinates
387* were, invalid, as indicated by the stat vector.
388*
389* For returns > 1, a detailed error message is set in
390* prjprm::err if enabled, see wcserr_enable().
391*
392*
393* ???set() - Specific setup routines for the prjprm struct
394* --------------------------------------------------------
395* Set up a prjprm struct for a particular projection according to information
396* supplied within it.
397*
398* Given and returned:
399* prj struct prjprm*
400* Projection parameters.
401*
402* Function return value:
403* int Status return value:
404* 0: Success.
405* 1: Null prjprm pointer passed.
406* 2: Invalid projection parameters.
407*
408* For returns > 1, a detailed error message is set in
409* prjprm::err if enabled, see wcserr_enable().
410*
411*
412* ???x2s() - Specific Cartesian-to-spherical deprojection routines
413* ----------------------------------------------------------------
414* Transform (x,y) coordinates in the plane of projection to native spherical
415* coordinates (phi,theta).
416*
417* Given and returned:
418* prj struct prjprm*
419* Projection parameters.
420*
421* Given:
422* nx,ny int Vector lengths.
423*
424* sxy,spt int Vector strides.
425*
426* x,y const double[]
427* Projected coordinates.
428*
429* Returned:
430* phi,theta double[] Longitude and latitude of the projected point in
431* native spherical coordinates [deg].
432*
433* stat int[] Status value for each vector element:
434* 0: Success.
435* 1: Invalid value of (x,y).
436*
437* Function return value:
438* int Status return value:
439* 0: Success.
440* 1: Null prjprm pointer passed.
441* 2: Invalid projection parameters.
442* 3: One or more of the (x,y) coordinates were
443* invalid, as indicated by the stat vector.
444*
445* For returns > 1, a detailed error message is set in
446* prjprm::err if enabled, see wcserr_enable().
447*
448*
449* ???s2x() - Specific spherical-to-Cartesian projection routines
450*---------------------------------------------------------------
451* Transform native spherical coordinates (phi,theta) to (x,y) coordinates in
452* the plane of projection.
453*
454* Given and returned:
455* prj struct prjprm*
456* Projection parameters.
457*
458* Given:
459* nphi,
460* ntheta int Vector lengths.
461*
462* spt,sxy int Vector strides.
463*
464* phi,theta const double[]
465* Longitude and latitude of the projected point in
466* native spherical coordinates [deg].
467*
468* Returned:
469* x,y double[] Projected coordinates.
470*
471* stat int[] Status value for each vector element:
472* 0: Success.
473* 1: Invalid value of (phi,theta).
474*
475* Function return value:
476* int Status return value:
477* 0: Success.
478* 1: Null prjprm pointer passed.
479* 2: Invalid projection parameters.
480* 4: One or more of the (phi,theta) coordinates
481* were, invalid, as indicated by the stat vector.
482*
483* For returns > 1, a detailed error message is set in
484* prjprm::err if enabled, see wcserr_enable().
485*
486*
487* prjprm struct - Projection parameters
488* -------------------------------------
489* The prjprm struct contains all information needed to project or deproject
490* native spherical coordinates. It consists of certain members that must be
491* set by the user ("given") and others that are set by the WCSLIB routines
492* ("returned"). Some of the latter are supplied for informational purposes
493* while others are for internal use only.
494*
495* int flag
496* (Given and returned) This flag must be set to zero whenever any of the
497* following prjprm struct members are set or changed:
498*
499* - prjprm::code,
500* - prjprm::r0,
501* - prjprm::pv[],
502* - prjprm::phi0,
503* - prjprm::theta0.
504*
505* This signals the initialization routine (prjset() or ???set()) to
506* recompute the returned members of the prjprm struct. flag will then be
507* reset to indicate that this has been done.
508*
509* Note that flag need not be reset when prjprm::bounds is changed.
510*
511* char code[4]
512* (Given) Three-letter projection code defined by the FITS standard.
513*
514* double r0
515* (Given) The radius of the generating sphere for the projection, a linear
516* scaling parameter. If this is zero, it will be reset to its default
517* value of 180/pi (the value for FITS WCS).
518*
519* double pv[30]
520* (Given) Projection parameters. These correspond to the PVi_ma keywords
521* in FITS, so pv[0] is PVi_0a, pv[1] is PVi_1a, etc., where i denotes the
522* latitude-like axis. Many projections use pv[1] (PVi_1a), some also use
523* pv[2] (PVi_2a) and SZP uses pv[3] (PVi_3a). ZPN is currently the only
524* projection that uses any of the others.
525*
526* Usage of the pv[] array as it applies to each projection is described in
527* the prologue to each trio of projection routines in prj.c.
528*
529* double phi0
530* (Given) The native longitude, phi_0 [deg], and ...
531* double theta0
532* (Given) ... the native latitude, theta_0 [deg], of the reference point,
533* i.e. the point (x,y) = (0,0). If undefined (set to a magic value by
534* prjini()) the initialization routine will set this to a
535* projection-specific default.
536*
537* int bounds
538* (Given) Controls bounds checking. If bounds&1 then enable strict bounds
539* checking for the spherical-to-Cartesian (s2x) transformation for the
540* AZP, SZP, TAN, SIN, ZPN, and COP projections. If bounds&2 then enable
541* strict bounds checking for the Cartesian-to-spherical transformation
542* (x2s) for the HPX and XPH projections. If bounds&4 then the Cartesian-
543* to-spherical transformations (x2s) will invoke prjbchk() to perform
544* bounds checking on the computed native coordinates, with a tolerance set
545* to suit each projection. bounds is set to 7 by prjini() by default
546* which enables all checks. Zero it to disable all checking.
547*
548* It is not necessary to reset the prjprm struct (via prjset() or
549* ???set()) when prjprm::bounds is changed.
550*
551* The remaining members of the prjprm struct are maintained by the setup
552* routines and must not be modified elsewhere:
553*
554* char name[40]
555* (Returned) Long name of the projection.
556*
557* Provided for information only, not used by the projection routines.
558*
559* int category
560* (Returned) Projection category matching the value of the relevant global
561* variable:
562*
563* - ZENITHAL,
564* - CYLINDRICAL,
565* - PSEUDOCYLINDRICAL,
566* - CONVENTIONAL,
567* - CONIC,
568* - POLYCONIC,
569* - QUADCUBE, and
570* - HEALPIX.
571*
572* The category name may be identified via the prj_categories character
573* array, e.g.
574*
575= struct prjprm prj;
576= ...
577= printf("%s\n", prj_categories[prj.category]);
578*
579* Provided for information only, not used by the projection routines.
580*
581* int pvrange
582* (Returned) Range of projection parameter indices: 100 times the first
583* allowed index plus the number of parameters, e.g. TAN is 0 (no
584* parameters), SZP is 103 (1 to 3), and ZPN is 30 (0 to 29).
585*
586* Provided for information only, not used by the projection routines.
587*
588* int simplezen
589* (Returned) True if the projection is a radially-symmetric zenithal
590* projection.
591*
592* Provided for information only, not used by the projection routines.
593*
594* int equiareal
595* (Returned) True if the projection is equal area.
596*
597* Provided for information only, not used by the projection routines.
598*
599* int conformal
600* (Returned) True if the projection is conformal.
601*
602* Provided for information only, not used by the projection routines.
603*
604* int global
605* (Returned) True if the projection can represent the whole sphere in a
606* finite, non-overlapped mapping.
607*
608* Provided for information only, not used by the projection routines.
609*
610* int divergent
611* (Returned) True if the projection diverges in latitude.
612*
613* Provided for information only, not used by the projection routines.
614*
615* double x0
616* (Returned) The offset in x, and ...
617* double y0
618* (Returned) ... the offset in y used to force (x,y) = (0,0) at
619* (phi_0,theta_0).
620*
621* struct wcserr *err
622* (Returned) If enabled, when an error status is returned, this struct
623* contains detailed information about the error, see wcserr_enable().
624*
625* void *padding
626* (An unused variable inserted for alignment purposes only.)
627*
628* double w[10]
629* (Returned) Intermediate floating-point values derived from the
630* projection parameters, cached here to save recomputation.
631*
632* Usage of the w[] array as it applies to each projection is described in
633* the prologue to each trio of projection routines in prj.c.
634*
635* int n
636* (Returned) Intermediate integer value (used only for the ZPN and HPX
637* projections).
638*
639* int (*prjx2s)(PRJX2S_ARGS)
640* (Returned) Pointer to the spherical projection ...
641* int (*prjs2x)(PRJ_ARGS)
642* (Returned) ... and deprojection routines.
643*
644*
645* Global variable: const char *prj_errmsg[] - Status return messages
646* ------------------------------------------------------------------
647* Error messages to match the status value returned from each function.
648*
649*===========================================================================*/
650
651#ifndef WCSLIB_PROJ
652#define WCSLIB_PROJ
653
654#ifdef __cplusplus
655extern "C" {
656#endif
657
658
659// Total number of projection parameters; 0 to PVN-1.
660#define PVN 30
661
662extern const char *prj_errmsg[];
663
664 enum prj_errmsg_enum {
665 PRJERR_SUCCESS = 0, // Success.
666 PRJERR_NULL_POINTER = 1, // Null prjprm pointer passed.
667 PRJERR_BAD_PARAM = 2, // Invalid projection parameters.
668 PRJERR_BAD_PIX = 3, // One or more of the (x, y) coordinates were
669 // invalid.
670 PRJERR_BAD_WORLD = 4 // One or more of the (phi, theta) coordinates
671 // were invalid.
672};
673
674 extern const int CONIC, CONVENTIONAL, CYLINDRICAL, POLYCONIC,
675 PSEUDOCYLINDRICAL, QUADCUBE, ZENITHAL, HEALPIX;
676extern const char prj_categories[9][32];
677
678extern const int prj_ncode;
679extern const char prj_codes[28][4];
680
681#ifdef PRJX2S_ARGS
682#undef PRJX2S_ARGS
683#endif
684
685#ifdef PRJS2X_ARGS
686#undef PRJS2X_ARGS
687#endif
688
689// For use in declaring deprojection function prototypes.
690#define PRJX2S_ARGS struct prjprm *prj, int nx, int ny, int sxy, int spt, \
691const double x[], const double y[], double phi[], double theta[], int stat[]
692
693// For use in declaring projection function prototypes.
694#define PRJS2X_ARGS struct prjprm *prj, int nx, int ny, int sxy, int spt, \
695const double phi[], const double theta[], double x[], double y[], int stat[]
696
697
698 struct prjprm {
699 // Initialization flag (see the prologue above).
700 //--------------------------------------------------------------------------
701 int flag; // Set to zero to force initialization.
702
703 // Parameters to be provided (see the prologue above).
704 //--------------------------------------------------------------------------
705 char code[4]; // Three-letter projection code.
706 double r0; // Radius of the generating sphere.
707 double pv[PVN]; // Projection parameters.
708 double phi0, theta0; // Fiducial native coordinates.
709 int bounds; // Controls bounds checking.
710
711 // Information derived from the parameters supplied.
712 //--------------------------------------------------------------------------
713 char name[40]; // Projection name.
714 int category; // Projection category.
715 int pvrange; // Range of projection parameter indices.
716 int simplezen; // Is it a simple zenithal projection?
717 int equiareal; // Is it an equal area projection?
718 int conformal; // Is it a conformal projection?
719 int global; // Can it map the whole sphere?
720 int divergent; // Does the projection diverge in latitude?
721 double x0, y0; // Fiducial offsets.
722
723 // Error handling
724 //--------------------------------------------------------------------------
725 struct wcserr *err;
726
727 // Private
728 //--------------------------------------------------------------------------
729 void *padding; // (Dummy inserted for alignment purposes.)
730 double w[10]; // Intermediate values.
731 int m, n; // Intermediate values.
732
733 int (*prjx2s)(PRJX2S_ARGS); // Pointers to the spherical projection and
734 int (*prjs2x)(PRJS2X_ARGS); // deprojection functions.
735};
736
737// Size of the prjprm struct in int units, used by the Fortran wrappers.
738#define PRJLEN (sizeof(struct prjprm)/sizeof(int))
739
740
741 int prjini(struct prjprm *prj);
742
743 int prjfree(struct prjprm *prj);
744
745 int prjsize(const struct prjprm *prj, int sizes[2]);
746
747 int prjprt(const struct prjprm *prj);
748
749 int prjperr(const struct prjprm *prj, const char *prefix);
750
751 int prjbchk(double tol, int nphi, int ntheta, int spt, double phi[],
752 double theta[], int stat[]);
753
754// Use the preprocessor to help declare function prototypes (see above).
755 int prjset(struct prjprm *prj);
756 int prjx2s(PRJX2S_ARGS);
757 int prjs2x(PRJS2X_ARGS);
758
759 int azpset(struct prjprm *prj);
760 int azpx2s(PRJX2S_ARGS);
761 int azps2x(PRJS2X_ARGS);
762
763 int szpset(struct prjprm *prj);
764 int szpx2s(PRJX2S_ARGS);
765 int szps2x(PRJS2X_ARGS);
766
767 int tanset(struct prjprm *prj);
768 int tanx2s(PRJX2S_ARGS);
769 int tans2x(PRJS2X_ARGS);
770
771 int stgset(struct prjprm *prj);
772 int stgx2s(PRJX2S_ARGS);
773 int stgs2x(PRJS2X_ARGS);
774
775 int sinset(struct prjprm *prj);
776 int sinx2s(PRJX2S_ARGS);
777 int sins2x(PRJS2X_ARGS);
778
779 int arcset(struct prjprm *prj);
780 int arcx2s(PRJX2S_ARGS);
781 int arcs2x(PRJS2X_ARGS);
782
783 int zpnset(struct prjprm *prj);
784 int zpnx2s(PRJX2S_ARGS);
785 int zpns2x(PRJS2X_ARGS);
786
787 int zeaset(struct prjprm *prj);
788 int zeax2s(PRJX2S_ARGS);
789 int zeas2x(PRJS2X_ARGS);
790
791 int airset(struct prjprm *prj);
792 int airx2s(PRJX2S_ARGS);
793 int airs2x(PRJS2X_ARGS);
794
795 int cypset(struct prjprm *prj);
796 int cypx2s(PRJX2S_ARGS);
797 int cyps2x(PRJS2X_ARGS);
798
799 int ceaset(struct prjprm *prj);
800 int ceax2s(PRJX2S_ARGS);
801 int ceas2x(PRJS2X_ARGS);
802
803 int carset(struct prjprm *prj);
804 int carx2s(PRJX2S_ARGS);
805 int cars2x(PRJS2X_ARGS);
806
807 int merset(struct prjprm *prj);
808 int merx2s(PRJX2S_ARGS);
809 int mers2x(PRJS2X_ARGS);
810
811 int sflset(struct prjprm *prj);
812 int sflx2s(PRJX2S_ARGS);
813 int sfls2x(PRJS2X_ARGS);
814
815 int parset(struct prjprm *prj);
816 int parx2s(PRJX2S_ARGS);
817 int pars2x(PRJS2X_ARGS);
818
819 int molset(struct prjprm *prj);
820 int molx2s(PRJX2S_ARGS);
821 int mols2x(PRJS2X_ARGS);
822
823 int aitset(struct prjprm *prj);
824 int aitx2s(PRJX2S_ARGS);
825 int aits2x(PRJS2X_ARGS);
826
827 int copset(struct prjprm *prj);
828 int copx2s(PRJX2S_ARGS);
829 int cops2x(PRJS2X_ARGS);
830
831 int coeset(struct prjprm *prj);
832 int coex2s(PRJX2S_ARGS);
833 int coes2x(PRJS2X_ARGS);
834
835 int codset(struct prjprm *prj);
836 int codx2s(PRJX2S_ARGS);
837 int cods2x(PRJS2X_ARGS);
838
839 int cooset(struct prjprm *prj);
840 int coox2s(PRJX2S_ARGS);
841 int coos2x(PRJS2X_ARGS);
842
843 int bonset(struct prjprm *prj);
844 int bonx2s(PRJX2S_ARGS);
845 int bons2x(PRJS2X_ARGS);
846
847 int pcoset(struct prjprm *prj);
848 int pcox2s(PRJX2S_ARGS);
849 int pcos2x(PRJS2X_ARGS);
850
851 int tscset(struct prjprm *prj);
852 int tscx2s(PRJX2S_ARGS);
853 int tscs2x(PRJS2X_ARGS);
854
855 int cscset(struct prjprm *prj);
856 int cscx2s(PRJX2S_ARGS);
857 int cscs2x(PRJS2X_ARGS);
858
859 int qscset(struct prjprm *prj);
860 int qscx2s(PRJX2S_ARGS);
861 int qscs2x(PRJS2X_ARGS);
862
863 int hpxset(struct prjprm *prj);
864 int hpxx2s(PRJX2S_ARGS);
865 int hpxs2x(PRJS2X_ARGS);
866
867 int xphset(struct prjprm *prj);
868 int xphx2s(PRJX2S_ARGS);
869 int xphs2x(PRJS2X_ARGS);
870
871
872// Deprecated.
873#define prjini_errmsg prj_errmsg
874#define prjprt_errmsg prj_errmsg
875#define prjset_errmsg prj_errmsg
876#define prjx2s_errmsg prj_errmsg
877#define prjs2x_errmsg prj_errmsg
878
879#ifdef __cplusplus
880}
881#endif
882
883#endif // WCSLIB_PROJ
airset
int airset(struct prjprm *prj)
Set up a prjprm struct for Airy's (AIR) projection.
codx2s
int codx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the conic equidistant (COD) projection.
cyps2x
int cyps2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the cylindrical perspective (CYP) projection.
molset
int molset(struct prjprm *prj)
Set up a prjprm struct for Mollweide's (MOL) projection.
tscs2x
int tscs2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the tangential spherical cube (TSC) projection.
parx2s
int parx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the parabolic (PAR) projection.
pcos2x
int pcos2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the polyconic (PCO) projection.
pcox2s
int pcox2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the polyconic (PCO) projection.
ceas2x
int ceas2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the cylindrical equal area (CEA) projection.
prj_errmsg_enum
prj_errmsg_enum
Definition prj.h:664
PRJERR_BAD_WORLD
@ PRJERR_BAD_WORLD
Definition prj.h:670
PRJERR_NULL_POINTER
@ PRJERR_NULL_POINTER
Definition prj.h:666
PRJERR_BAD_PARAM
@ PRJERR_BAD_PARAM
Definition prj.h:667
PRJERR_SUCCESS
@ PRJERR_SUCCESS
Definition prj.h:665
PRJERR_BAD_PIX
@ PRJERR_BAD_PIX
Definition prj.h:668
airx2s
int airx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for Airy's (AIR) projection.
prj_ncode
const int prj_ncode
The number of recognized three-letter projection codes.
aitx2s
int aitx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the Hammer-Aitoff (AIT) projection.
coox2s
int coox2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the conic orthomorphic (COO) projection.
szpx2s
int szpx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the slant zenithal perspective (SZP) projection.
sflx2s
int sflx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the Sanson-Flamsteed (SFL) projection.
zeaset
int zeaset(struct prjprm *prj)
Set up a prjprm struct for the zenithal/azimuthal equal area (ZEA) projection.
aitset
int aitset(struct prjprm *prj)
Set up a prjprm struct for the Hammer-Aitoff (AIT) projection.
cooset
int cooset(struct prjprm *prj)
Set up a prjprm struct for the conic orthomorphic (COO) projection.
tanset
int tanset(struct prjprm *prj)
Set up a prjprm struct for the gnomonic (TAN) projection.
carset
int carset(struct prjprm *prj)
Set up a prjprm struct for the plate carrée (CAR) projection.
cypset
int cypset(struct prjprm *prj)
Set up a prjprm struct for the cylindrical perspective (CYP) projection.
PRJX2S_ARGS
#define PRJX2S_ARGS
For use in declaring deprojection function prototypes.
Definition prj.h:690
bons2x
int bons2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for Bonne's (BON) projection.
ZENITHAL
const int ZENITHAL
Identifier for zenithal/azimuthal projections.
Definition prj.h:675
hpxx2s
int hpxx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the HEALPix (HPX) projection.
prjfree
int prjfree(struct prjprm *prj)
Destructor for the prjprm struct.
bonx2s
int bonx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for Bonne's (BON) projection.
merx2s
int merx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for Mercator's (MER) projection.
sfls2x
int sfls2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the Sanson-Flamsteed (SFL) projection.
zpnx2s
int zpnx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the zenithal/azimuthal polynomial (ZPN) projection.
copx2s
int copx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the conic perspective (COP) projection.
PSEUDOCYLINDRICAL
const int PSEUDOCYLINDRICAL
Identifier for pseudocylindrical projections.
Definition prj.h:675
prj_codes
const char prj_codes[28][4]
Recognized three-letter projection codes.
prjperr
int prjperr(const struct prjprm *prj, const char *prefix)
Print error messages from a prjprm struct.
arcx2s
int arcx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the zenithal/azimuthal equidistant (ARC) projection.
stgset
int stgset(struct prjprm *prj)
Set up a prjprm struct for the stereographic (STG) projection.
ceaset
int ceaset(struct prjprm *prj)
Set up a prjprm struct for the cylindrical equal area (CEA) projection.
xphx2s
int xphx2s(PRJX2S_ARGS)
xphs2x
int xphs2x(PRJS2X_ARGS)
qscset
int qscset(struct prjprm *prj)
Set up a prjprm struct for the quadrilateralized spherical cube (QSC) projection.
HEALPIX
const int HEALPIX
Identifier for the HEALPix projection.
Definition prj.h:675
mols2x
int mols2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for Mollweide's (MOL) projection.
szps2x
int szps2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the slant zenithal perspective (SZP) projection.
QUADCUBE
const int QUADCUBE
Identifier for quadcube projections.
Definition prj.h:675
airs2x
int airs2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for Airy's (AIR) projection.
cops2x
int cops2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the conic perspective (COP) projection.
zpns2x
int zpns2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the zenithal/azimuthal polynomial (ZPN) projection.
prjbchk
int prjbchk(double tol, int nphi, int ntheta, int spt, double phi[], double theta[], int stat[])
Bounds checking on native coordinates.
sflset
int sflset(struct prjprm *prj)
Set up a prjprm struct for the Sanson-Flamsteed (SFL) projection.
qscs2x
int qscs2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the quadrilateralized spherical cube (QSC) projection.
zeax2s
int zeax2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the zenithal/azimuthal equal area (ZEA) projection.
molx2s
int molx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for Mollweide's (MOL) projection.
CYLINDRICAL
const int CYLINDRICAL
Identifier for cylindrical projections.
Definition prj.h:674
prjprt
int prjprt(const struct prjprm *prj)
Print routine for the prjprm struct.
stgx2s
int stgx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the stereographic (STG) projection.
cscset
int cscset(struct prjprm *prj)
Set up a prjprm struct for the COBE spherical cube (CSC) projection.
aits2x
int aits2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the Hammer-Aitoff (AIT) projection.
azpx2s
int azpx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the zenithal/azimuthal perspective (AZP) projection.
prjx2s
int prjx2s(PRJX2S_ARGS)
Generic Cartesian-to-spherical deprojection.
prj_categories
const char prj_categories[9][32]
Projection categories.
tans2x
int tans2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the gnomonic (TAN) projection.
hpxset
int hpxset(struct prjprm *prj)
Set up a prjprm struct for the HEALPix (HPX) projection.
arcs2x
int arcs2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the zenithal/azimuthal equidistant (ARC) projection.
pcoset
int pcoset(struct prjprm *prj)
Set up a prjprm struct for the polyconic (PCO) projection.
PRJS2X_ARGS
#define PRJS2X_ARGS
For use in declaring projection function prototypes.
Definition prj.h:694
tscset
int tscset(struct prjprm *prj)
Set up a prjprm struct for the tangential spherical cube (TSC) projection.
bonset
int bonset(struct prjprm *prj)
Set up a prjprm struct for Bonne's (BON) projection.
POLYCONIC
const int POLYCONIC
Identifier for polyconic projections.
Definition prj.h:674
coeset
int coeset(struct prjprm *prj)
Set up a prjprm struct for the conic equal area (COE) projection.
cars2x
int cars2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the plate carrée (CAR) projection.
stgs2x
int stgs2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the stereographic (STG) projection.
sinset
int sinset(struct prjprm *prj)
Set up a prjprm struct for the orthographic/synthesis (SIN) projection.
tscx2s
int tscx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the tangential spherical cube (TSC) projection.
azps2x
int azps2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the zenithal/azimuthal perspective (AZP) projection.
sins2x
int sins2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the orthographic/synthesis (SIN) projection.
prjs2x
int prjs2x(PRJS2X_ARGS)
Generic spherical-to-Cartesian projection.
azpset
int azpset(struct prjprm *prj)
Set up a prjprm struct for the zenithal/azimuthal perspective (AZP) projection.
arcset
int arcset(struct prjprm *prj)
Set up a prjprm struct for the zenithal/azimuthal equidistant (ARC) projection.
copset
int copset(struct prjprm *prj)
Set up a prjprm struct for the conic perspective (COP) projection.
PVN
#define PVN
Total number of projection parameters.
Definition prj.h:660
CONVENTIONAL
const int CONVENTIONAL
Identifier for conventional projections.
Definition prj.h:674
zpnset
int zpnset(struct prjprm *prj)
Set up a prjprm struct for the zenithal/azimuthal polynomial (ZPN) projection.
cscs2x
int cscs2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the COBE spherical cube (CSC) projection.
prj_errmsg
const char * prj_errmsg[]
Status return messages.
tanx2s
int tanx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the gnomonic (TAN) projection.
merset
int merset(struct prjprm *prj)
Set up a prjprm struct for Mercator's (MER) projection.
parset
int parset(struct prjprm *prj)
Set up a prjprm struct for the parabolic (PAR) projection.
prjset
int prjset(struct prjprm *prj)
Generic setup routine for the prjprm struct.
coex2s
int coex2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the conic equal area (COE) projection.
prjini
int prjini(struct prjprm *prj)
Default constructor for the prjprm struct.
mers2x
int mers2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for Mercator's (MER) projection.
zeas2x
int zeas2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the zenithal/azimuthal equal area (ZEA) projection.
CONIC
const int CONIC
Identifier for conic projections.
pars2x
int pars2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the parabolic (PAR) projection.
sinx2s
int sinx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the orthographic/synthesis (SIN) projection.
coos2x
int coos2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the conic orthomorphic (COO) projection.
prjsize
int prjsize(const struct prjprm *prj, int sizes[2])
Compute the size of a prjprm struct.
carx2s
int carx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the plate carrée (CAR) projection.
hpxs2x
int hpxs2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the HEALPix (HPX) projection.
coes2x
int coes2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the conic equal area (COE) projection.
szpset
int szpset(struct prjprm *prj)
Set up a prjprm struct for the slant zenithal perspective (SZP) projection.
codset
int codset(struct prjprm *prj)
Set up a prjprm struct for the conic equidistant (COD) projection.
qscx2s
int qscx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the quadrilateralized spherical cube (QSC) projection.
cscx2s
int cscx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the COBE spherical cube (CSC) projection.
xphset
int xphset(struct prjprm *prj)
cods2x
int cods2x(PRJS2X_ARGS)
Spherical-to-Cartesian transformation for the conic equidistant (COD) projection.
ceax2s
int ceax2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the cylindrical equal area (CEA) projection.
cypx2s
int cypx2s(PRJX2S_ARGS)
Cartesian-to-spherical transformation for the cylindrical perspective (CYP) projection.
prjprm
Projection parameters.
Definition prj.h:698
prjprm::y0
double y0
Definition prj.h:721
prjprm::err
struct wcserr * err
Definition prj.h:725
prjprm::r0
double r0
Definition prj.h:706
prjprm::w
double w[10]
Definition prj.h:730
prjprm::pv
double pv[PVN]
Definition prj.h:707
prjprm::code
char code[4]
Definition prj.h:705
prjprm::divergent
int divergent
Definition prj.h:720
prjprm::phi0
double phi0
Definition prj.h:708
prjprm::padding
void * padding
Definition prj.h:729
prjprm::n
int n
Definition prj.h:731
prjprm::x0
double x0
Definition prj.h:721
prjprm::name
char name[40]
Definition prj.h:713
prjprm::equiareal
int equiareal
Definition prj.h:717
prjprm::bounds
int bounds
Definition prj.h:709
prjprm::pvrange
int pvrange
Definition prj.h:715
prjprm::flag
int flag
Definition prj.h:701
prjprm::conformal
int conformal
Definition prj.h:718
prjprm::global
int global
Definition prj.h:719
prjprm::prjs2x
int(* prjs2x)(PRJS2X_ARGS)
Definition prj.h:734
prjprm::theta0
double theta0
Definition prj.h:708
prjprm::prjx2s
int(* prjx2s)(PRJX2S_ARGS)
Definition prj.h:733
prjprm::category
int category
Definition prj.h:714
prjprm::m
int m
Definition prj.h:731
prjprm::simplezen
int simplezen
Definition prj.h:716
wcserr
Error message handling.
Definition wcserr.h:243