ref: d0ae2e369e0221e796f4b58255b21ce3592d80dc
dir: /sys/src/cmd/scat/util.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include "sky.h"
double PI_180 = 0.0174532925199432957692369;
double TWOPI = 6.2831853071795864769252867665590057683943387987502;
double LN2 = 0.69314718055994530941723212145817656807550013436025;
static double angledangle=(180./PI)*MILLIARCSEC;
int
rint(char *p, int n)
{
int i=0;
while(*p==' ' && n)
p++, --n;
while(n--)
i=i*10+*p++-'0';
return i;
}
DAngle
dangle(Angle angle)
{
return angle*angledangle;
}
Angle
angle(DAngle dangle)
{
return dangle/angledangle;
}
double
rfloat(char *p, int n)
{
double i, d=0;
while(*p==' ' && n)
p++, --n;
if(*p == '+')
return rfloat(p+1, n-1);
if(*p == '-')
return -rfloat(p+1, n-1);
while(*p == ' ' && n)
p++, --n;
if(n == 0)
return 0.0;
while(n-- && *p!='.')
d = d*10+*p++-'0';
if(n <= 0)
return d;
p++;
i = 1;
while(n--)
d+=(*p++-'0')/(i*=10.);
return d;
}
int
sign(int c)
{
if(c=='-')
return -1;
return 1;
}
char*
hms(Angle a)
{
static char buf[20];
double x;
int h, m, s, ts;
x=DEG(a)/15;
x += 0.5/36000.; /* round up half of 0.1 sec */
h = floor(x);
x -= h;
x *= 60;
m = floor(x);
x -= m;
x *= 60;
s = floor(x);
x -= s;
ts = 10*x;
sprint(buf, "%dh%.2dm%.2d.%ds", h, m, s, ts);
return buf;
}
char*
dms(Angle a)
{
static char buf[20];
double x;
int sign, d, m, s, ts;
x = DEG(a);
sign='+';
if(a<0){
sign='-';
x=-x;
}
x += 0.5/36000.; /* round up half of 0.1 arcsecond */
d = floor(x);
x -= d;
x *= 60;
m = floor(x);
x -= m;
x *= 60;
s = floor(x);
x -= s;
ts = floor(10*x);
sprint(buf, "%c%d°%.2d'%.2d.%d\"", sign, d, m, s, ts);
return buf;
}
char*
ms(Angle a)
{
static char buf[20];
double x;
int d, m, s, ts;
x = DEG(a);
x += 0.5/36000.; /* round up half of 0.1 arcsecond */
d = floor(x);
x -= d;
x *= 60;
m = floor(x);
x -= m;
x *= 60;
s = floor(x);
x -= s;
ts = floor(10*x);
if(d != 0)
sprint(buf, "%d°%.2d'%.2d.%d\"", d, m, s, ts);
else
sprint(buf, "%.2d'%.2d.%d\"", m, s, ts);
return buf;
}
char*
hm(Angle a)
{
static char buf[20];
double x;
int h, m, n;
x = DEG(a)/15;
x += 0.5/600.; /* round up half of tenth of minute */
h = floor(x);
x -= h;
x *= 60;
m = floor(x);
x -= m;
x *= 10;
n = floor(x);
sprint(buf, "%dh%.2d.%1dm", h, m, n);
return buf;
}
char*
hm5(Angle a)
{
static char buf[20];
double x;
int h, m;
x = DEG(a)/15;
x += 2.5/60.; /* round up 2.5m */
h = floor(x);
x -= h;
x *= 60;
m = floor(x);
m -= m % 5;
sprint(buf, "%dh%.2dm", h, m);
return buf;
}
char*
dm(Angle a)
{
static char buf[20];
double x;
int sign, d, m, n;
x = DEG(a);
sign='+';
if(a<0){
sign='-';
x=-x;
}
x += 0.5/600.; /* round up half of tenth of arcminute */
d = floor(x);
x -= d;
x *= 60;
m = floor(x);
x -= m;
x *= 10;
n = floor(x);
sprint(buf, "%c%d°%.2d.%.1d'", sign, d, m, n);
return buf;
}
char*
deg(Angle a)
{
static char buf[20];
double x;
int sign, d;
x = DEG(a);
sign='+';
if(a<0){
sign='-';
x=-x;
}
x += 0.5; /* round up half degree */
d = floor(x);
sprint(buf, "%c%d°", sign, d);
return buf;
}
char*
getword(char *ou, char *in)
{
int c;
for(;;) {
c = *in++;
if(c == ' ' || c == '\t')
continue;
if(c == 0)
return 0;
break;
}
if(c == '\'')
for(;;) {
if(c >= 'A' && c <= 'Z')
c += 'a' - 'A';
*ou++ = c;
c = *in++;
if(c == 0)
return 0;
if(c == '\'') {
*ou = 0;
return in-1;
}
}
for(;;) {
if(c >= 'A' && c <= 'Z')
c += 'a' - 'A';
*ou++ = c;
c = *in++;
if(c == ' ' || c == '\t' || c == 0) {
*ou = 0;
return in-1;
}
}
}
/*
* Read formatted angle. Must contain no embedded blanks
*/
Angle
getra(char *p)
{
Rune r;
char *q;
Angle f, d;
int neg;
neg = 0;
d = 0;
while(*p == ' ')
p++;
for(;;) {
if(*p == ' ' || *p=='\0')
goto Return;
if(*p == '-') {
neg = 1;
p++;
}
if(*p == '+') {
neg = 0;
p++;
}
q = p;
f = strtod(p, &q);
if(q > p) {
p = q;
}
p += chartorune(&r, p);
switch(r) {
default:
Return:
if(neg)
d = -d;
return RAD(d);
case 'h':
d += f*15;
break;
case 'm':
d += f/4;
break;
case 's':
d += f/240;
break;
case L'°':
d += f;
break;
case '\'':
d += f/60;
break;
case '\"':
d += f/3600;
break;
}
}
}
double
xsqrt(double a)
{
if(a < 0)
return 0;
return sqrt(a);
}
Angle
dist(Angle ra1, Angle dec1, Angle ra2, Angle dec2)
{
double a;
a = sin(dec1) * sin(dec2) +
cos(dec1) * cos(dec2) *
cos(ra1 - ra2);
a = atan2(xsqrt(1 - a*a), a);
if(a < 0)
a = -a;
return a;
}
int
dogamma(Pix c)
{
float f;
f = c - gam.min;
if(f < 1)
f = 1;
if(gam.absgamma == 1)
c = f * gam.mult2;
else
c = exp(log(f*gam.mult1) * gam.absgamma) * 255;
if(c > 255)
c = 255;
if(gam.neg)
c = 255-c;
return c;
}