PJ_nsper.c
3.25 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
#ifndef lint
static const char SCCSID[]="@(#)PJ_nsper.c 4.1 94/02/15 GIE REL";
#endif
#define PROJ_PARMS__ \
double height; \
double sinph0; \
double cosph0; \
double p; \
double rp; \
double pn1; \
double pfact; \
double h; \
double cg; \
double sg; \
double sw; \
double cw; \
int mode; \
int tilt;
#define PJ_LIB__
#include "projects.h"
PROJ_HEAD(nsper, "Near-sided perspective") "\n\tAzi, Sph\n\th=";
PROJ_HEAD(tpers, "Tilted perspective") "\n\tAzi, Sph\n\ttilt= azi= h=";
# define EPS10 1.e-10
# define N_POLE 0
# define S_POLE 1
# define EQUIT 2
# define OBLIQ 3
FORWARD(s_forward); /* spheroid */
double coslam, cosphi, sinphi;
sinphi = sin(lp.phi);
cosphi = cos(lp.phi);
coslam = cos(lp.lam);
switch (P->mode) {
case OBLIQ:
xy.y = P->sinph0 * sinphi + P->cosph0 * cosphi * coslam;
break;
case EQUIT:
xy.y = cosphi * coslam;
break;
case S_POLE:
xy.y = - sinphi;
break;
case N_POLE:
xy.y = sinphi;
break;
}
if (xy.y < P->rp) F_ERROR;
xy.y = P->pn1 / (P->p - xy.y);
xy.x = xy.y * cosphi * sin(lp.lam);
switch (P->mode) {
case OBLIQ:
xy.y *= (P->cosph0 * sinphi -
P->sinph0 * cosphi * coslam);
break;
case EQUIT:
xy.y *= sinphi;
break;
case N_POLE:
coslam = - coslam;
case S_POLE:
xy.y *= cosphi * coslam;
break;
}
if (P->tilt) {
double yt, ba;
yt = xy.y * P->cg + xy.x * P->sg;
ba = 1. / (yt * P->sw * P->h + P->cw);
xy.x = (xy.x * P->cg - xy.y * P->sg) * P->cw * ba;
xy.y = yt * ba;
}
return (xy);
}
INVERSE(s_inverse); /* spheroid */
double rh, cosz, sinz;
if (P->tilt) {
double bm, bq, yt;
yt = 1./(P->pn1 - xy.y * P->sw);
bm = P->pn1 * xy.x * yt;
bq = P->pn1 * xy.y * P->cw * yt;
xy.x = bm * P->cg + bq * P->sg;
xy.y = bq * P->cg - bm * P->sg;
}
rh = hypot(xy.x, xy.y);
if ((sinz = 1. - rh * rh * P->pfact) < 0.) I_ERROR;
sinz = (P->p - sqrt(sinz)) / (P->pn1 / rh + rh / P->pn1);
cosz = sqrt(1. - sinz * sinz);
if (fabs(rh) <= EPS10) {
lp.lam = 0.;
lp.phi = P->phi0;
} else {
switch (P->mode) {
case OBLIQ:
lp.phi = asin(cosz * P->sinph0 + xy.y * sinz * P->cosph0 / rh);
xy.y = (cosz - P->sinph0 * sin(lp.phi)) * rh;
xy.x *= sinz * P->cosph0;
break;
case EQUIT:
lp.phi = asin(xy.y * sinz / rh);
xy.y = cosz * rh;
xy.x *= sinz;
break;
case N_POLE:
lp.phi = asin(cosz);
xy.y = -xy.y;
break;
case S_POLE:
lp.phi = - asin(cosz);
break;
}
lp.lam = atan2(xy.x, xy.y);
}
return (lp);
}
FREEUP; if (P) pj_dalloc(P); }
static PJ *
setup(PJ *P) {
if ((P->height = pj_param(P->params, "dh").f) <= 0.) E_ERROR(-30);
if (fabs(fabs(P->phi0) - HALFPI) < EPS10)
P->mode = P->phi0 < 0. ? S_POLE : N_POLE;
else if (fabs(P->phi0) < EPS10)
P->mode = EQUIT;
else {
P->mode = OBLIQ;
P->sinph0 = sin(P->phi0);
P->cosph0 = cos(P->phi0);
}
P->pn1 = P->height / P->a; /* normalize by radius */
P->p = 1. + P->pn1;
P->rp = 1. / P->p;
P->h = 1. / P->pn1;
P->pfact = (P->p + 1.) * P->h;
P->inv = s_inverse;
P->fwd = s_forward;
P->es = 0.;
return P;
}
ENTRY0(nsper)
P->tilt = 0;
ENDENTRY(setup(P))
ENTRY0(tpers)
double omega, gamma;
omega = pj_param(P->params, "dtilt").f * DEG_TO_RAD;
gamma = pj_param(P->params, "dazi").f * DEG_TO_RAD;
P->tilt = 1;
P->cg = cos(gamma); P->sg = sin(gamma);
P->cw = cos(omega); P->sw = sin(omega);
ENDENTRY(setup(P))