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/* Copyright (c) 1991 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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|
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/* |
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* Program to convert lamp color from table and compute radiance. |
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*/ |
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|
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#include <stdio.h> |
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|
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#define PI 3.14159265358979323846 |
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|
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extern char *gets(), *strcpy(); |
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extern double atof(); |
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extern float *matchlamp(); |
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|
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/* lamp parameters */ |
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#define LTYPE 0 |
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#define LUNIT 1 |
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#define LGEOM 2 |
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#define LOUTP 3 |
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#define NPARAMS 4 |
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|
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int typecheck(), unitcheck(), geomcheck(), outpcheck(); |
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|
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float *lampcolor; /* the lamp color (RGB) */ |
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double unit2meter; /* conversion from units to meters */ |
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double projarea; /* projected area for this geometry */ |
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double lumens; /* total lamp lumens */ |
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|
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struct { |
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char *name; |
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char value[64]; |
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int (*check)(); |
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char *help; |
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} param[NPARAMS] = { |
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{ "lamp type", "white", typecheck, |
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"The lamp type is a string which corresponds to one of the types registered\n\ |
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in the lamp table file. A value of \"white\" means an uncolored source,\n\ |
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which may be preferable because it results in a color balanced image." }, |
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{ "length unit", "meter", unitcheck, |
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"Unit must be one of: \"meter\", \"centimeter\", \"foot\", or \"inch\".\n\ |
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These may be abbreviated as a single letter." }, |
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{ "lamp geometry", "polygon", geomcheck, |
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"The lamp geometry must be one of: \"polygon\", \"sphere\", \"cylinder\"\n\ |
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or \"ring\". These may be abbreviated as a single letter." }, |
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{ "total lamp lumens", "0", outpcheck, |
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"This is the overall light output of the lamp and its fixture. If you do\n\ |
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not know this value explicitly, you can compute the approximate lumens\n\ |
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by multiplying the input wattage by 14 for incandescent fixtures or 70\n\ |
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for fluorescent fixtures." }, |
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}; |
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|
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|
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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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char *lamptab = "lamp.tab"; |
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char buf[64]; |
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int i; |
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|
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if (argc > 1) lamptab = argv[1]; |
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if (loadlamps(lamptab) == 0) { |
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fprintf(stderr, "%s: no such lamp table\n", lamptab); |
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exit(1); |
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} |
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printf("Program to compute lamp radiance. Enter '?' for help.\n"); |
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for ( ; ; ) { |
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i = 0; |
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while (i < NPARAMS) { |
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printf("Enter %s [%s]: ", param[i].name, |
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param[i].value); |
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if (gets(buf) == NULL) |
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exit(0); |
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if (buf[0] == '?') { |
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puts(param[i].help); |
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continue; |
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} |
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if (buf[0]) |
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strcpy(param[i].value, buf); |
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if (!(*param[i].check)(param[i].value)) { |
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fprintf(stderr, "%s: bad value for %s\n", |
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param[i].value, param[i].name); |
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continue; |
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} |
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i++; |
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} |
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compute(); |
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} |
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} |
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|
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|
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typecheck(s) /* check lamp type */ |
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char *s; |
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{ |
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lampcolor = matchlamp(s); |
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return(lampcolor != NULL); |
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} |
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|
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|
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unitcheck(s) /* compute conversion to meters */ |
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char *s; |
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{ |
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int len = strlen(s); |
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|
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switch (*s) { |
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case 'm': |
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if (strncmp(s, "meters", len)) |
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return(0); |
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unit2meter = 1.0; |
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return(1); |
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case 'c': |
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if (strncmp(s, "centimeters", len) && strncmp(s, "cms", len)) |
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return(0); |
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unit2meter = 0.01; |
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return(1); |
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case 'f': |
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if (strncmp(s, "foot", len) && strncmp(s, "feet", len)) |
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return(0); |
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unit2meter = 0.3048; |
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return(1); |
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case 'i': |
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if (strncmp(s, "inches", len)) |
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return(0); |
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unit2meter = 0.0254; |
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return(1); |
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} |
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return(0); |
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} |
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|
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|
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geomcheck(s) /* check/set lamp geometry */ |
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char *s; |
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{ |
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int len = strlen(s); |
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|
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switch (*s) { |
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case 'p': |
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if (strncmp(s, "polygonal", len)) |
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return(0); |
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return(getpolygon()); |
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case 's': |
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if (strncmp(s, "sphere", len) && strncmp(s, "spherical", len)) |
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return(0); |
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return(getsphere()); |
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case 'c': |
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if (strncmp(s,"cylinder",len) && strncmp(s,"cylindrical",len)) |
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return(0); |
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return(getcylinder()); |
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case 'r': |
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if (strncmp(s, "ring", len) && strncmp(s, "disk", len)) |
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return(0); |
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return(getring()); |
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} |
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return(0); |
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} |
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|
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|
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outpcheck(s) /* check lumen output value */ |
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register char *s; |
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{ |
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if ((*s < '0' || *s > '9') && *s != '.') |
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return(0); |
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lumens = atof(s); |
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return(1); |
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} |
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|
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|
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compute() /* compute lamp radiance */ |
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{ |
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double whiteval; |
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|
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whiteval = lumens/470./projarea; |
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|
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printf("Lamp color (RGB) = %f %f %f\n", |
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lampcolor[0]*whiteval, |
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lampcolor[1]*whiteval, |
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lampcolor[2]*whiteval); |
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} |
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|
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|
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getd(dp) /* get a positive double from stdin */ |
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double *dp; |
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{ |
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char buf[32]; |
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|
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if (gets(buf) == NULL) |
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return(0); |
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if ((buf[0] < '0' || buf[0] > '9') && buf[0] != '.') |
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return(0); |
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*dp = atof(buf); |
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return(1); |
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} |
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|
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|
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getpolygon() /* get projected area for a polygon */ |
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{ |
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printf("Polygon area? "); |
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if (!getd(&projarea)) |
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return(0); |
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projarea *= unit2meter*unit2meter; |
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projarea *= PI; |
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return(1); |
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} |
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|
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|
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getsphere() /* get projected area for a sphere */ |
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{ |
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double radius; |
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|
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printf("Sphere radius? "); |
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if (!getd(&radius)) |
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return(0); |
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radius *= unit2meter; |
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projarea = 4.*PI*PI*radius*radius; |
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return(1); |
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} |
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|
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|
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getcylinder() /* get projected area for a cylinder */ |
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{ |
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double length, radius; |
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|
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printf("Cylinder length? "); |
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if (!getd(&length)) |
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return(0); |
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length *= unit2meter; |
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printf("Cylinder radius? "); |
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if (!getd(&radius)) |
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return(0); |
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radius *= unit2meter; |
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projarea = PI*PI*2.*PI*radius*length; |
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return(1); |
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} |
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|
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|
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getring() /* get projected area for a ring */ |
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{ |
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double radius; |
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|
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printf("Disk radius? "); |
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if (!getd(&radius)) |
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return(0); |
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radius *= unit2meter; |
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projarea = PI*PI*radius*radius; |
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return(1); |
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} |
