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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
#define PJ_LIB__
#include <errno.h>
#include "proj.h"
#include "projects.h"
#include "proj_math.h"
enum Mode {
N_POLE = 0,
S_POLE = 1,
EQUIT = 2,
OBLIQ = 3
};
struct pj_opaque {
double height;
double sinph0;
double cosph0;
double p;
double rp;
double pn1;
double pfact;
double h;
double cg;
double sg;
double sw;
double cw;
enum Mode mode;
int tilt;
};
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
static XY s_forward (LP lp, PJ *P) { /* Spheroidal, forward */
XY xy = {0.0,0.0};
struct pj_opaque *Q = P->opaque;
double coslam, cosphi, sinphi;
sinphi = sin(lp.phi);
cosphi = cos(lp.phi);
coslam = cos(lp.lam);
switch (Q->mode) {
case OBLIQ:
xy.y = Q->sinph0 * sinphi + Q->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 < Q->rp) {
proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
return xy;
}
xy.y = Q->pn1 / (Q->p - xy.y);
xy.x = xy.y * cosphi * sin(lp.lam);
switch (Q->mode) {
case OBLIQ:
xy.y *= (Q->cosph0 * sinphi -
Q->sinph0 * cosphi * coslam);
break;
case EQUIT:
xy.y *= sinphi;
break;
case N_POLE:
coslam = - coslam;
/*-fallthrough*/
case S_POLE:
xy.y *= cosphi * coslam;
break;
}
if (Q->tilt) {
double yt, ba;
yt = xy.y * Q->cg + xy.x * Q->sg;
ba = 1. / (yt * Q->sw * Q->h + Q->cw);
xy.x = (xy.x * Q->cg - xy.y * Q->sg) * Q->cw * ba;
xy.y = yt * ba;
}
return xy;
}
static LP s_inverse (XY xy, PJ *P) { /* Spheroidal, inverse */
LP lp = {0.0,0.0};
struct pj_opaque *Q = P->opaque;
double rh, cosz, sinz;
if (Q->tilt) {
double bm, bq, yt;
yt = 1./(Q->pn1 - xy.y * Q->sw);
bm = Q->pn1 * xy.x * yt;
bq = Q->pn1 * xy.y * Q->cw * yt;
xy.x = bm * Q->cg + bq * Q->sg;
xy.y = bq * Q->cg - bm * Q->sg;
}
rh = hypot(xy.x, xy.y);
if ((sinz = 1. - rh * rh * Q->pfact) < 0.) {
proj_errno_set(P, PJD_ERR_TOLERANCE_CONDITION);
return lp;
}
sinz = (Q->p - sqrt(sinz)) / (Q->pn1 / rh + rh / Q->pn1);
cosz = sqrt(1. - sinz * sinz);
if (fabs(rh) <= EPS10) {
lp.lam = 0.;
lp.phi = P->phi0;
} else {
switch (Q->mode) {
case OBLIQ:
lp.phi = asin(cosz * Q->sinph0 + xy.y * sinz * Q->cosph0 / rh);
xy.y = (cosz - Q->sinph0 * sin(lp.phi)) * rh;
xy.x *= sinz * Q->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;
}
static PJ *setup(PJ *P) {
struct pj_opaque *Q = P->opaque;
if ((Q->height = pj_param(P->ctx, P->params, "dh").f) <= 0.)
return pj_default_destructor(P, PJD_ERR_H_LESS_THAN_ZERO);
if (fabs(fabs(P->phi0) - M_HALFPI) < EPS10)
Q->mode = P->phi0 < 0. ? S_POLE : N_POLE;
else if (fabs(P->phi0) < EPS10)
Q->mode = EQUIT;
else {
Q->mode = OBLIQ;
Q->sinph0 = sin(P->phi0);
Q->cosph0 = cos(P->phi0);
}
Q->pn1 = Q->height / P->a; /* normalize by radius */
Q->p = 1. + Q->pn1;
Q->rp = 1. / Q->p;
Q->h = 1. / Q->pn1;
Q->pfact = (Q->p + 1.) * Q->h;
P->inv = s_inverse;
P->fwd = s_forward;
P->es = 0.;
return P;
}
PJ *PROJECTION(nsper) {
struct pj_opaque *Q = pj_calloc (1, sizeof (struct pj_opaque));
if (0==Q)
return pj_default_destructor (P, ENOMEM);
P->opaque = Q;
Q->tilt = 0;
return setup(P);
}
PJ *PROJECTION(tpers) {
double omega, gamma;
struct pj_opaque *Q = pj_calloc (1, sizeof (struct pj_opaque));
if (0==Q)
return pj_default_destructor (P, ENOMEM);
P->opaque = Q;
omega = pj_param(P->ctx, P->params, "rtilt").f;
gamma = pj_param(P->ctx, P->params, "razi").f;
Q->tilt = 1;
Q->cg = cos(gamma); Q->sg = sin(gamma);
Q->cw = cos(omega); Q->sw = sin(omega);
return setup(P);
}
|
