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
|
#include <u.h>
#include <libc.h>
#include "map.h"
/* Given two lat-lon pairs, find an orientation for the
-o option of "map" that will place those two points
on the equator of a standard projection, equally spaced
about the prime meridian.
-w and -l options are suggested also.
Option -t prints out a series of
coordinates that follows the (great circle) track
in the original coordinate system,
followed by ".
This data is just right for map -t.
Option -i inverts the map top-to-bottom.
*/
struct place pole;
struct coord twist;
int track;
int inv = -1;
extern void doroute(double, double, double, double, double);
void
dorot(double a, double b, double *x, double *y, void (*f)(struct place *))
{
struct place g;
deg2rad(a,&g.nlat);
deg2rad(b,&g.wlon);
(*f)(&g);
*x = g.nlat.l/RAD;
*y = g.wlon.l/RAD;
}
void
rotate(double a, double b, double *x, double *y)
{
dorot(a,b,x,y,normalize);
}
void
rinvert(double a, double b, double *x, double *y)
{
dorot(a,b,x,y,invert);
}
main(int argc, char **argv)
{
#pragma ref argv
double an,aw,bn,bw;
ARGBEGIN {
case 't':
track = 1;
break;
case 'i':
inv = 1;
break;
default:
exits("route: bad option");
} ARGEND;
if (argc<4) {
print("use route [-t] [-i] lat lon lat lon\n");
exits("arg count");
}
an = atof(argv[0]);
aw = atof(argv[1]);
bn = atof(argv[2]);
bw = atof(argv[3]);
doroute(inv*90.,an,aw,bn,bw);
return 0;
}
void
doroute(double dir, double an, double aw, double bn, double bw)
{
double an1,aw1,bn1,bw1,pn,pw;
double theta;
double cn,cw,cn1,cw1;
int i,n;
orient(an,aw,0.);
rotate(bn,bw,&bn1,&bw1);
/* printf("b %f %f\n",bn1,bw1);*/
orient(an,aw,bw1);
rinvert(0.,dir,&pn,&pw);
/* printf("p %f %f\n",pn,pw);*/
orient(pn,pw,0.);
rotate(an,aw,&an1,&aw1);
rotate(bn,bw,&bn1,&bw1);
theta = (aw1+bw1)/2;
/* printf("a %f %f \n",an1,aw1);*/
orient(pn,pw,theta);
rotate(an,aw,&an1,&aw1);
rotate(bn,bw,&bn1,&bw1);
if(fabs(aw1-bw1)>180)
if(theta<0.) theta+=180;
else theta -= 180;
orient(pn,pw,theta);
rotate(an,aw,&an1,&aw1);
rotate(bn,bw,&bn1,&bw1);
if(!track) {
double dlat, dlon, t;
/* printf("A %.4f %.4f\n",an1,aw1); */
/* printf("B %.4f %.4f\n",bn1,bw1); */
cw1 = fabs(bw1-aw1); /* angular difference for map margins */
/* while (aw<0.0)
aw += 360.;
while (bw<0.0)
bw += 360.; */
dlon = fabs(aw-bw);
if (dlon>180)
dlon = 360-dlon;
dlat = fabs(an-bn);
printf("-o %.4f %.4f %.4f -w %.2f %.2f %.2f %.2f \n",
pn,pw,theta, -0.3*cw1, .3*cw1, -.6*cw1, .6*cw1);
} else {
cn1 = 0;
n = 1 + fabs(bw1-aw1)/.2;
for(i=0;i<=n;i++) {
cw1 = aw1 + i*(bw1-aw1)/n;
rinvert(cn1,cw1,&cn,&cw);
printf("%f %f\n",cn,cw);
}
printf("\"\n");
}
}
|