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/* Copyright (c) 1992 Regents of the University of California */ |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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static const char RCSid[] = "$Id$"; |
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#endif |
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|
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/* |
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* gensky.c - program to generate sky functions. |
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* Our zenith is along the Z-axis, the X-axis |
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*/ |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <math.h> |
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|
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#include <ctype.h> |
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#include "sun.h" |
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#include "color.h" |
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|
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extern char *strcpy(), *strcat(), *malloc(); |
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extern double stadj(), sdec(), sazi(), salt(); |
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#ifndef PI |
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#define PI 3.14159265358979323846 |
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#endif |
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|
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#define PI 3.141592654 |
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|
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#define DOT(v1,v2) (v1[0]*v2[0]+v1[1]*v2[1]+v1[2]*v2[2]) |
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|
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#define S_CLEAR 1 |
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#define S_OVER 2 |
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#define S_UNIF 3 |
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#define S_INTER 4 |
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|
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#define overcast ((skytype==S_OVER)|(skytype==S_UNIF)) |
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|
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double normsc(); |
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/* sun calculation constants */ |
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extern double s_latitude; |
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extern double s_longitude; |
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extern double s_meridian; |
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|
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#undef toupper |
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#define toupper(c) ((c) & ~0x20) /* ASCII trick to convert case */ |
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|
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/* European and North American zones */ |
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struct { |
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char zname[8]; /* time zone name (all caps) */ |
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float zmer; /* standard meridian */ |
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} tzone[] = { |
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{"YST", 135}, {"YDT", 120}, |
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{"PST", 120}, {"PDT", 105}, |
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{"MST", 105}, {"MDT", 90}, |
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{"CST", 90}, {"CDT", 75}, |
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{"EST", 75}, {"EDT", 60}, |
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{"AST", 60}, {"ADT", 45}, |
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{"NST", 52.5}, {"NDT", 37.5}, |
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{"GMT", 0}, {"BST", -15}, |
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{"CET", -15}, {"CEST", -30}, |
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{"EET", -30}, {"EEST", -45}, |
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{"AST", -45}, {"ADT", -60}, |
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{"GST", -60}, {"GDT", -75}, |
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{"IST", -82.5}, {"IDT", -97.5}, |
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{"JST", -135}, {"NDT", -150}, |
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{"NZST", -180}, {"NZDT", -195}, |
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{"", 0} |
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}; |
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/* required values */ |
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int year = 0; /* year (optional) */ |
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int month, day; /* date */ |
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double hour; /* time */ |
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int tsolar; /* 0=standard, 1=solar */ |
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double altitude, azimuth; /* or solar angles */ |
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/* default values */ |
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int cloudy = 0; /* 1=standard, 2=uniform */ |
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int skytype = S_CLEAR; /* sky type */ |
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int dosun = 1; |
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double zenithbr = -1.0; |
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double turbidity = 2.75; |
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double zenithbr = 0.0; |
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int u_zenith = 0; /* -1=irradiance, 1=radiance */ |
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double turbidity = 2.45; |
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double gprefl = 0.2; |
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/* computed values */ |
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double sundir[3]; |
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double groundbr; |
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double F2; |
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double solarbr = -1.0; |
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double solarbr = 0.0; |
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int u_solar = 0; /* -1=irradiance, 1=radiance */ |
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|
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char *progname; |
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char errmsg[128]; |
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|
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void computesky(void); |
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void printsky(void); |
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void printdefaults(void); |
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void userror(char *msg); |
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double normsc(void); |
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int cvthour(char *hs); |
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void printhead(int ac, char **av); |
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main(argc, argv) |
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int argc; |
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char *argv[]; |
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|
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int |
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main( |
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int argc, |
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char *argv[] |
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) |
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{ |
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int got_meridian = 0; |
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int i; |
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progname = argv[0]; |
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day = atoi(argv[2]); |
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if (day < 1 || day > 31) |
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userror("bad day"); |
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hour = atof(argv[3]); |
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if (hour < 0 || hour >= 24) |
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userror("bad hour"); |
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tsolar = argv[3][0] == '+'; |
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got_meridian = cvthour(argv[3]); |
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} |
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for (i = 4; i < argc; i++) |
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if (argv[i][0] == '-' || argv[i][0] == '+') |
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switch (argv[i][1]) { |
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case 's': |
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cloudy = 0; |
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skytype = S_CLEAR; |
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dosun = argv[i][0] == '+'; |
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break; |
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case 'y': |
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year = atoi(argv[++i]); |
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break; |
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case 'r': |
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case 'R': |
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u_solar = argv[i][1]=='R' ? -1 : 1; |
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solarbr = atof(argv[++i]); |
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break; |
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case 'c': |
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cloudy = argv[i][0] == '+' ? 2 : 1; |
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dosun = 0; |
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skytype = S_OVER; |
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break; |
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case 'u': |
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skytype = S_UNIF; |
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break; |
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case 'i': |
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skytype = S_INTER; |
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dosun = argv[i][0] == '+'; |
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break; |
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case 't': |
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turbidity = atof(argv[++i]); |
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break; |
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case 'b': |
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case 'B': |
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u_zenith = argv[i][1]=='B' ? -1 : 1; |
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zenithbr = atof(argv[++i]); |
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break; |
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case 'g': |
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s_longitude = atof(argv[++i]) * (PI/180); |
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break; |
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case 'm': |
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if (got_meridian) { |
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++i; |
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break; /* time overrides */ |
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} |
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s_meridian = atof(argv[++i]) * (PI/180); |
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break; |
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default: |
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else |
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userror("bad option"); |
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|
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if (fabs(s_meridian-s_longitude) > 30*PI/180) |
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> |
if (year && (year < 1950) | (year > 2050)) |
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fprintf(stderr, |
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< |
"%s: warning: %.1f hours btwn. standard meridian and longitude\n", |
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> |
"%s: warning - year should be in range 1950-2050\n", |
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progname); |
182 |
> |
if (month && !tsolar && fabs(s_meridian-s_longitude) > 45*PI/180) |
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> |
fprintf(stderr, |
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> |
"%s: warning - %.1f hours btwn. standard meridian and longitude\n", |
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progname, (s_longitude-s_meridian)*12/PI); |
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|
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printhead(argc, argv); |
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|
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computesky(); |
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printsky(); |
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|
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exit(0); |
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} |
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|
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|
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computesky() /* compute sky parameters */ |
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> |
void |
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computesky(void) /* compute sky parameters */ |
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{ |
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double normfactor; |
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/* compute solar direction */ |
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if (month) { /* from date and time */ |
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int jd; |
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double sd, st; |
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> |
double sd, st = hour; |
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|
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< |
jd = jdate(month, day); /* Julian date */ |
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sd = sdec(jd); /* solar declination */ |
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if (tsolar) /* solar time */ |
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st = hour; |
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else |
209 |
< |
st = hour + stadj(jd); |
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> |
if (year) { /* Michalsky algorithm? */ |
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double mjd = mjdate(year, month, day, hour); |
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> |
if (tsolar) |
207 |
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sd = msdec(mjd, NULL); |
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> |
else |
209 |
> |
sd = msdec(mjd, &st); |
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> |
} else { |
211 |
> |
int jd = jdate(month, day); /* Julian date */ |
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> |
sd = sdec(jd); /* solar declination */ |
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> |
if (!tsolar) /* get solar time? */ |
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st = hour + stadj(jd); |
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} |
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altitude = salt(sd, st); |
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azimuth = sazi(sd, st); |
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printf("# Local solar time: %.2f\n", st); |
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printf("# Solar altitude and azimuth: %.1f %.1f\n", |
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180./PI*altitude, 180./PI*azimuth); |
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} |
222 |
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if (!cloudy && altitude > 87.*PI/180.) { |
222 |
> |
if (!overcast && altitude > 87.*PI/180.) { |
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fprintf(stderr, |
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"%s: warning - sun too close to zenith, reducing altitude to 87 degrees\n", |
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progname); |
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sundir[1] = -cos(azimuth)*cos(altitude); |
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sundir[2] = sin(altitude); |
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|
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+ |
/* Compute normalization factor */ |
235 |
+ |
switch (skytype) { |
236 |
+ |
case S_UNIF: |
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normfactor = 1.0; |
238 |
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break; |
239 |
+ |
case S_OVER: |
240 |
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normfactor = 0.777778; |
241 |
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break; |
242 |
+ |
case S_CLEAR: |
243 |
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F2 = 0.274*(0.91 + 10.0*exp(-3.0*(PI/2.0-altitude)) + |
244 |
+ |
0.45*sundir[2]*sundir[2]); |
245 |
+ |
normfactor = normsc()/F2/PI; |
246 |
+ |
break; |
247 |
+ |
case S_INTER: |
248 |
+ |
F2 = (2.739 + .9891*sin(.3119+2.6*altitude)) * |
249 |
+ |
exp(-(PI/2.0-altitude)*(.4441+1.48*altitude)); |
250 |
+ |
normfactor = normsc()/F2/PI; |
251 |
+ |
break; |
252 |
+ |
} |
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/* Compute zenith brightness */ |
254 |
< |
if (zenithbr <= 0.0) |
255 |
< |
if (cloudy) { |
254 |
> |
if (u_zenith == -1) |
255 |
> |
zenithbr /= normfactor*PI; |
256 |
> |
else if (u_zenith == 0) { |
257 |
> |
if (overcast) |
258 |
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zenithbr = 8.6*sundir[2] + .123; |
259 |
< |
zenithbr *= 1000.0/WHTEFFICACY; |
168 |
< |
} else { |
259 |
> |
else |
260 |
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zenithbr = (1.376*turbidity-1.81)*tan(altitude)+0.38; |
261 |
< |
zenithbr *= 1000.0/SKYEFFICACY; |
262 |
< |
} |
263 |
< |
if (zenithbr < 0.0) |
264 |
< |
zenithbr = 0.0; |
174 |
< |
/* Compute horizontal radiance */ |
175 |
< |
if (cloudy) { |
176 |
< |
if (cloudy == 2) |
177 |
< |
groundbr = zenithbr; |
261 |
> |
if (skytype == S_INTER) |
262 |
> |
zenithbr = (zenithbr + 8.6*sundir[2] + .123)/2.0; |
263 |
> |
if (zenithbr < 0.0) |
264 |
> |
zenithbr = 0.0; |
265 |
|
else |
266 |
< |
groundbr = zenithbr*0.777778; |
180 |
< |
printf("# Ground ambient level: %f\n", groundbr); |
181 |
< |
} else { |
182 |
< |
F2 = 0.274*(0.91 + 10.0*exp(-3.0*(PI/2.0-altitude)) + |
183 |
< |
0.45*sundir[2]*sundir[2]); |
184 |
< |
groundbr = zenithbr*normsc(altitude)/F2/PI; |
185 |
< |
printf("# Ground ambient level: %f\n", groundbr); |
186 |
< |
if (sundir[2] > 0.0 && solarbr != 0.0) { |
187 |
< |
if (solarbr < 0.0) |
188 |
< |
solarbr = 1.5e9/SUNEFFICACY * |
189 |
< |
(1.147 - .147/(sundir[2]>.16?sundir[2]:.16)); |
190 |
< |
groundbr += solarbr*6e-5*sundir[2]/PI; |
191 |
< |
} else |
192 |
< |
dosun = 0; |
266 |
> |
zenithbr *= 1000.0/SKYEFFICACY; |
267 |
|
} |
268 |
+ |
/* Compute horizontal radiance */ |
269 |
+ |
groundbr = zenithbr*normfactor; |
270 |
+ |
printf("# Ground ambient level: %.1f\n", groundbr); |
271 |
+ |
if (!overcast && sundir[2] > 0.0 && (!u_solar || solarbr > 0.0)) { |
272 |
+ |
if (u_solar == -1) |
273 |
+ |
solarbr /= 6e-5*sundir[2]; |
274 |
+ |
else if (u_solar == 0) { |
275 |
+ |
solarbr = 1.5e9/SUNEFFICACY * |
276 |
+ |
(1.147 - .147/(sundir[2]>.16?sundir[2]:.16)); |
277 |
+ |
if (skytype == S_INTER) |
278 |
+ |
solarbr *= 0.15; /* fudge factor! */ |
279 |
+ |
} |
280 |
+ |
groundbr += 6e-5/PI*solarbr*sundir[2]; |
281 |
+ |
} else |
282 |
+ |
dosun = 0; |
283 |
|
groundbr *= gprefl; |
284 |
|
} |
285 |
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|
286 |
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|
287 |
< |
printsky() /* print out sky */ |
287 |
> |
void |
288 |
> |
printsky(void) /* print out sky */ |
289 |
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{ |
290 |
|
if (dosun) { |
291 |
|
printf("\nvoid light solar\n"); |
297 |
|
} |
298 |
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|
299 |
|
printf("\nvoid brightfunc skyfunc\n"); |
300 |
< |
printf("2 skybright skybright.cal\n"); |
300 |
> |
printf("2 skybr skybright.cal\n"); |
301 |
|
printf("0\n"); |
302 |
< |
if (cloudy) |
303 |
< |
printf("3 %d %.2e %.2e\n", cloudy, zenithbr, groundbr); |
302 |
> |
if (overcast) |
303 |
> |
printf("3 %d %.2e %.2e\n", skytype, zenithbr, groundbr); |
304 |
|
else |
305 |
< |
printf("7 -1 %.2e %.2e %.2e %f %f %f\n", zenithbr, groundbr, |
306 |
< |
F2, sundir[0], sundir[1], sundir[2]); |
305 |
> |
printf("7 %d %.2e %.2e %.2e %f %f %f\n", |
306 |
> |
skytype, zenithbr, groundbr, F2, |
307 |
> |
sundir[0], sundir[1], sundir[2]); |
308 |
|
} |
309 |
|
|
310 |
|
|
311 |
< |
printdefaults() /* print default values */ |
311 |
> |
void |
312 |
> |
printdefaults(void) /* print default values */ |
313 |
|
{ |
314 |
< |
if (cloudy == 1) |
314 |
> |
switch (skytype) { |
315 |
> |
case S_OVER: |
316 |
|
printf("-c\t\t\t\t# Cloudy sky\n"); |
317 |
< |
else if (cloudy == 2) |
318 |
< |
printf("+c\t\t\t\t# Uniform cloudy sky\n"); |
319 |
< |
else if (dosun) |
320 |
< |
printf("+s\t\t\t\t# Sunny sky with sun\n"); |
321 |
< |
else |
322 |
< |
printf("-s\t\t\t\t# Sunny sky without sun\n"); |
317 |
> |
break; |
318 |
> |
case S_UNIF: |
319 |
> |
printf("-u\t\t\t\t# Uniform cloudy sky\n"); |
320 |
> |
break; |
321 |
> |
case S_INTER: |
322 |
> |
if (dosun) |
323 |
> |
printf("+i\t\t\t\t# Intermediate sky with sun\n"); |
324 |
> |
else |
325 |
> |
printf("-i\t\t\t\t# Intermediate sky without sun\n"); |
326 |
> |
break; |
327 |
> |
case S_CLEAR: |
328 |
> |
if (dosun) |
329 |
> |
printf("+s\t\t\t\t# Sunny sky with sun\n"); |
330 |
> |
else |
331 |
> |
printf("-s\t\t\t\t# Sunny sky without sun\n"); |
332 |
> |
break; |
333 |
> |
} |
334 |
|
printf("-g %f\t\t\t# Ground plane reflectance\n", gprefl); |
335 |
|
if (zenithbr > 0.0) |
336 |
|
printf("-b %f\t\t\t# Zenith radiance (watts/ster/m2\n", zenithbr); |
342 |
|
} |
343 |
|
|
344 |
|
|
345 |
< |
userror(msg) /* print usage error and quit */ |
346 |
< |
char *msg; |
345 |
> |
void |
346 |
> |
userror( /* print usage error and quit */ |
347 |
> |
char *msg |
348 |
> |
) |
349 |
|
{ |
350 |
|
if (msg != NULL) |
351 |
|
fprintf(stderr, "%s: Use error - %s\n", progname, msg); |
357 |
|
|
358 |
|
|
359 |
|
double |
360 |
< |
normsc(theta) /* compute normalization factor (E0*F2/L0) */ |
255 |
< |
double theta; |
360 |
> |
normsc(void) /* compute normalization factor (E0*F2/L0) */ |
361 |
|
{ |
362 |
< |
static double nf[5] = {2.766521, 0.547665, |
363 |
< |
-0.369832, 0.009237, 0.059229}; |
362 |
> |
static double nfc[2][5] = { |
363 |
> |
/* clear sky approx. */ |
364 |
> |
{2.766521, 0.547665, -0.369832, 0.009237, 0.059229}, |
365 |
> |
/* intermediate sky approx. */ |
366 |
> |
{3.5556, -2.7152, -1.3081, 1.0660, 0.60227}, |
367 |
> |
}; |
368 |
> |
double *nf; |
369 |
|
double x, nsc; |
370 |
< |
register int i; |
370 |
> |
int i; |
371 |
|
/* polynomial approximation */ |
372 |
< |
x = (theta - PI/4.0)/(PI/4.0); |
373 |
< |
nsc = nf[4]; |
374 |
< |
for (i = 3; i >= 0; i--) |
372 |
> |
nf = nfc[skytype==S_INTER]; |
373 |
> |
x = (altitude - PI/4.0)/(PI/4.0); |
374 |
> |
nsc = nf[i=4]; |
375 |
> |
while (i--) |
376 |
|
nsc = nsc*x + nf[i]; |
377 |
|
|
378 |
|
return(nsc); |
379 |
|
} |
380 |
|
|
381 |
|
|
382 |
< |
printhead(ac, av) /* print command header */ |
383 |
< |
register int ac; |
384 |
< |
register char **av; |
382 |
> |
int |
383 |
> |
cvthour( /* convert hour string */ |
384 |
> |
char *hs |
385 |
> |
) |
386 |
> |
{ |
387 |
> |
char *cp = hs; |
388 |
> |
int i, j; |
389 |
> |
|
390 |
> |
if ( (tsolar = *cp == '+') ) cp++; /* solar time? */ |
391 |
> |
while (isdigit(*cp)) cp++; |
392 |
> |
if (*cp == ':') |
393 |
> |
hour = atoi(hs) + atoi(++cp)/60.0; |
394 |
> |
else { |
395 |
> |
hour = atof(hs); |
396 |
> |
if (*cp == '.') cp++; |
397 |
> |
} |
398 |
> |
while (isdigit(*cp)) cp++; |
399 |
> |
if (!*cp) |
400 |
> |
return(0); |
401 |
> |
if (tsolar || !isalpha(*cp)) { |
402 |
> |
fprintf(stderr, "%s: bad time format: %s\n", progname, hs); |
403 |
> |
exit(1); |
404 |
> |
} |
405 |
> |
i = 0; |
406 |
> |
do { |
407 |
> |
for (j = 0; cp[j]; j++) |
408 |
> |
if (toupper(cp[j]) != tzone[i].zname[j]) |
409 |
> |
break; |
410 |
> |
if (!cp[j] && !tzone[i].zname[j]) { |
411 |
> |
s_meridian = tzone[i].zmer * (PI/180); |
412 |
> |
return(1); |
413 |
> |
} |
414 |
> |
} while (tzone[i++].zname[0]); |
415 |
> |
|
416 |
> |
fprintf(stderr, "%s: unknown time zone: %s\n", progname, cp); |
417 |
> |
fprintf(stderr, "Known time zones:\n\t%s", tzone[0].zname); |
418 |
> |
for (i = 1; tzone[i].zname[0]; i++) |
419 |
> |
fprintf(stderr, " %s", tzone[i].zname); |
420 |
> |
putc('\n', stderr); |
421 |
> |
exit(1); |
422 |
> |
} |
423 |
> |
|
424 |
> |
|
425 |
> |
void |
426 |
> |
printhead( /* print command header */ |
427 |
> |
int ac, |
428 |
> |
char **av |
429 |
> |
) |
430 |
|
{ |
431 |
|
putchar('#'); |
432 |
|
while (ac--) { |