| 1 | 
greg | 
1.1 | 
#ifndef lint | 
| 2 | 
schorsch | 
2.22 | 
static const char       RCSid[] = "$Id: func.c,v 2.21 2004/02/12 18:55:50 greg Exp $"; | 
| 3 | 
greg | 
1.1 | 
#endif | 
| 4 | 
  | 
  | 
/* | 
| 5 | 
  | 
  | 
 *  func.c - interface to calcomp functions. | 
| 6 | 
greg | 
2.14 | 
 */ | 
| 7 | 
  | 
  | 
 | 
| 8 | 
greg | 
2.15 | 
#include "copyright.h" | 
| 9 | 
greg | 
1.1 | 
 | 
| 10 | 
schorsch | 
2.22 | 
#include <math.h> | 
| 11 | 
  | 
  | 
 | 
| 12 | 
greg | 
1.1 | 
#include  "ray.h" | 
| 13 | 
greg | 
2.21 | 
#include  "paths.h" | 
| 14 | 
greg | 
1.1 | 
#include  "otypes.h" | 
| 15 | 
greg | 
2.2 | 
#include  "func.h" | 
| 16 | 
greg | 
1.1 | 
 | 
| 17 | 
greg | 
2.2 | 
 | 
| 18 | 
greg | 
1.21 | 
#define  INITFILE       "rayinit.cal" | 
| 19 | 
greg | 
2.2 | 
#define  CALSUF         ".cal" | 
| 20 | 
  | 
  | 
#define  LCALSUF        4 | 
| 21 | 
greg | 
2.10 | 
char  REFVNAME[] = "`FILE_REFCNT"; | 
| 22 | 
greg | 
1.21 | 
 | 
| 23 | 
greg | 
1.13 | 
XF  unitxf = {                  /* identity transform */ | 
| 24 | 
greg | 
2.8 | 
        {{1.0, 0.0, 0.0, 0.0}, | 
| 25 | 
  | 
  | 
        {0.0, 1.0, 0.0, 0.0}, | 
| 26 | 
  | 
  | 
        {0.0, 0.0, 1.0, 0.0}, | 
| 27 | 
  | 
  | 
        {0.0, 0.0, 0.0, 1.0}}, | 
| 28 | 
greg | 
1.13 | 
        1.0 | 
| 29 | 
  | 
  | 
}; | 
| 30 | 
  | 
  | 
 | 
| 31 | 
greg | 
1.12 | 
XF  funcxf;                     /* current transformation */ | 
| 32 | 
  | 
  | 
static OBJREC  *fobj = NULL;    /* current function object */ | 
| 33 | 
  | 
  | 
static RAY  *fray = NULL;       /* current function ray */ | 
| 34 | 
greg | 
1.1 | 
 | 
| 35 | 
greg | 
2.20 | 
static double  l_erf(char *), l_erfc(char *), l_arg(char *); | 
| 36 | 
greg | 
1.1 | 
 | 
| 37 | 
greg | 
2.2 | 
 | 
| 38 | 
schorsch | 
2.22 | 
extern MFUNC * | 
| 39 | 
  | 
  | 
getfunc(        /* get function for this modifier */ | 
| 40 | 
  | 
  | 
        OBJREC  *m, | 
| 41 | 
  | 
  | 
        int  ff, | 
| 42 | 
  | 
  | 
        unsigned int  ef, | 
| 43 | 
  | 
  | 
        int  dofwd | 
| 44 | 
  | 
  | 
) | 
| 45 | 
greg | 
2.2 | 
{ | 
| 46 | 
  | 
  | 
        static char  initfile[] = INITFILE; | 
| 47 | 
  | 
  | 
        char  sbuf[MAXSTR]; | 
| 48 | 
  | 
  | 
        register char  **arg; | 
| 49 | 
  | 
  | 
        register MFUNC  *f; | 
| 50 | 
  | 
  | 
        int  ne, na; | 
| 51 | 
  | 
  | 
        register int  i; | 
| 52 | 
  | 
  | 
                                        /* check to see if done already */ | 
| 53 | 
  | 
  | 
        if ((f = (MFUNC *)m->os) != NULL) | 
| 54 | 
  | 
  | 
                return(f); | 
| 55 | 
greg | 
2.7 | 
        fobj = NULL; fray = NULL; | 
| 56 | 
greg | 
2.2 | 
        if (initfile[0]) {              /* initialize on first call */ | 
| 57 | 
greg | 
2.14 | 
                esupport |= E_VARIABLE|E_FUNCTION|E_INCHAN|E_RCONST|E_REDEFW; | 
| 58 | 
  | 
  | 
                esupport &= ~(E_OUTCHAN); | 
| 59 | 
greg | 
2.2 | 
                setcontext(""); | 
| 60 | 
  | 
  | 
                scompile("Dx=$1;Dy=$2;Dz=$3;", NULL, 0); | 
| 61 | 
  | 
  | 
                scompile("Nx=$4;Ny=$5;Nz=$6;", NULL, 0); | 
| 62 | 
  | 
  | 
                scompile("Px=$7;Py=$8;Pz=$9;", NULL, 0); | 
| 63 | 
greg | 
2.6 | 
                scompile("T=$10;Ts=$25;Rdot=$11;", NULL, 0); | 
| 64 | 
greg | 
2.2 | 
                scompile("S=$12;Tx=$13;Ty=$14;Tz=$15;", NULL, 0); | 
| 65 | 
  | 
  | 
                scompile("Ix=$16;Iy=$17;Iz=$18;", NULL, 0); | 
| 66 | 
  | 
  | 
                scompile("Jx=$19;Jy=$20;Jz=$21;", NULL, 0); | 
| 67 | 
  | 
  | 
                scompile("Kx=$22;Ky=$23;Kz=$24;", NULL, 0); | 
| 68 | 
greg | 
2.17 | 
                scompile("Lu=$26;Lv=$27;", NULL, 0); | 
| 69 | 
greg | 
2.2 | 
                funset("arg", 1, '=', l_arg); | 
| 70 | 
  | 
  | 
                funset("erf", 1, ':', l_erf); | 
| 71 | 
  | 
  | 
                funset("erfc", 1, ':', l_erfc); | 
| 72 | 
  | 
  | 
                setnoisefuncs(); | 
| 73 | 
greg | 
2.11 | 
                setprismfuncs(); | 
| 74 | 
greg | 
2.2 | 
                loadfunc(initfile); | 
| 75 | 
  | 
  | 
                initfile[0] = '\0'; | 
| 76 | 
  | 
  | 
        } | 
| 77 | 
  | 
  | 
        if ((na = m->oargs.nsargs) <= ff) | 
| 78 | 
  | 
  | 
                goto toofew; | 
| 79 | 
  | 
  | 
        arg = m->oargs.sarg; | 
| 80 | 
  | 
  | 
        if ((f = (MFUNC *)calloc(1, sizeof(MFUNC))) == NULL) | 
| 81 | 
  | 
  | 
                goto memerr; | 
| 82 | 
  | 
  | 
        i = strlen(arg[ff]);                    /* set up context */ | 
| 83 | 
  | 
  | 
        if (i == 1 && arg[ff][0] == '.') | 
| 84 | 
  | 
  | 
                setcontext(f->ctx = "");        /* "." means no file */ | 
| 85 | 
  | 
  | 
        else { | 
| 86 | 
greg | 
2.14 | 
                strcpy(sbuf,arg[ff]);           /* file name is context */ | 
| 87 | 
greg | 
2.2 | 
                if (i > LCALSUF && !strcmp(sbuf+i-LCALSUF, CALSUF)) | 
| 88 | 
  | 
  | 
                        sbuf[i-LCALSUF] = '\0'; /* remove suffix */ | 
| 89 | 
  | 
  | 
                setcontext(f->ctx = savestr(sbuf)); | 
| 90 | 
  | 
  | 
                if (!vardefined(REFVNAME)) {    /* file loaded? */ | 
| 91 | 
greg | 
2.5 | 
                        loadfunc(arg[ff]); | 
| 92 | 
greg | 
2.2 | 
                        varset(REFVNAME, '=', 1.0); | 
| 93 | 
  | 
  | 
                } else                          /* reference_count++ */ | 
| 94 | 
  | 
  | 
                        varset(REFVNAME, '=', varvalue(REFVNAME)+1.0); | 
| 95 | 
  | 
  | 
        } | 
| 96 | 
  | 
  | 
        curfunc = NULL;                 /* parse expressions */ | 
| 97 | 
  | 
  | 
        sprintf(sbuf, "%s \"%s\"", ofun[m->otype].funame, m->oname); | 
| 98 | 
  | 
  | 
        for (i=0, ne=0; ef && i < na; i++, ef>>=1) | 
| 99 | 
  | 
  | 
                if (ef & 1) {                   /* flagged as an expression? */ | 
| 100 | 
  | 
  | 
                        if (ne >= MAXEXPR) | 
| 101 | 
  | 
  | 
                                objerror(m, INTERNAL, "too many expressions"); | 
| 102 | 
  | 
  | 
                        initstr(arg[i], sbuf, 0); | 
| 103 | 
  | 
  | 
                        f->ep[ne++] = getE1(); | 
| 104 | 
  | 
  | 
                        if (nextc != EOF) | 
| 105 | 
  | 
  | 
                                syntax("unexpected character"); | 
| 106 | 
  | 
  | 
                } | 
| 107 | 
  | 
  | 
        if (ef) | 
| 108 | 
  | 
  | 
                goto toofew; | 
| 109 | 
  | 
  | 
        if (i <= ff)                    /* find transform args */ | 
| 110 | 
  | 
  | 
                i = ff+1; | 
| 111 | 
  | 
  | 
        while (i < na && arg[i][0] != '-') | 
| 112 | 
  | 
  | 
                i++; | 
| 113 | 
  | 
  | 
        if (i == na)                    /* no transform */ | 
| 114 | 
  | 
  | 
                f->f = f->b = &unitxf; | 
| 115 | 
  | 
  | 
        else {                          /* get transform */ | 
| 116 | 
  | 
  | 
                if ((f->b = (XF *)malloc(sizeof(XF))) == NULL) | 
| 117 | 
greg | 
2.3 | 
                        goto memerr; | 
| 118 | 
greg | 
2.2 | 
                if (invxf(f->b, na-i, arg+i) != na-i) | 
| 119 | 
  | 
  | 
                        objerror(m, USER, "bad transform"); | 
| 120 | 
  | 
  | 
                if (f->b->sca < 0.0) | 
| 121 | 
  | 
  | 
                        f->b->sca = -f->b->sca; | 
| 122 | 
  | 
  | 
                if (dofwd) {                    /* do both transforms */ | 
| 123 | 
  | 
  | 
                        if ((f->f = (XF *)malloc(sizeof(XF))) == NULL) | 
| 124 | 
greg | 
2.3 | 
                                goto memerr; | 
| 125 | 
greg | 
2.2 | 
                        xf(f->f, na-i, arg+i); | 
| 126 | 
  | 
  | 
                        if (f->f->sca < 0.0) | 
| 127 | 
  | 
  | 
                                f->f->sca = -f->f->sca; | 
| 128 | 
  | 
  | 
                } | 
| 129 | 
  | 
  | 
        } | 
| 130 | 
  | 
  | 
        m->os = (char *)f; | 
| 131 | 
  | 
  | 
        return(f); | 
| 132 | 
  | 
  | 
toofew: | 
| 133 | 
greg | 
2.4 | 
        objerror(m, USER, "too few string arguments"); | 
| 134 | 
greg | 
2.2 | 
memerr: | 
| 135 | 
  | 
  | 
        error(SYSTEM, "out of memory in getfunc"); | 
| 136 | 
schorsch | 
2.22 | 
        return NULL; /* pro forma return */ | 
| 137 | 
greg | 
2.2 | 
} | 
| 138 | 
  | 
  | 
 | 
| 139 | 
  | 
  | 
 | 
| 140 | 
schorsch | 
2.22 | 
extern void | 
| 141 | 
  | 
  | 
freefunc(                       /* free memory associated with modifier */ | 
| 142 | 
  | 
  | 
        OBJREC  *m | 
| 143 | 
  | 
  | 
) | 
| 144 | 
greg | 
2.2 | 
{ | 
| 145 | 
  | 
  | 
        register MFUNC  *f; | 
| 146 | 
  | 
  | 
        register int  i; | 
| 147 | 
  | 
  | 
 | 
| 148 | 
  | 
  | 
        if ((f = (MFUNC *)m->os) == NULL) | 
| 149 | 
  | 
  | 
                return; | 
| 150 | 
  | 
  | 
        for (i = 0; f->ep[i] != NULL; i++) | 
| 151 | 
  | 
  | 
                epfree(f->ep[i]); | 
| 152 | 
  | 
  | 
        if (f->ctx[0]) {                        /* done with definitions */ | 
| 153 | 
  | 
  | 
                setcontext(f->ctx); | 
| 154 | 
  | 
  | 
                i = varvalue(REFVNAME)-.5;      /* reference_count-- */ | 
| 155 | 
  | 
  | 
                if (i > 0) | 
| 156 | 
  | 
  | 
                        varset(REFVNAME, '=', (double)i); | 
| 157 | 
  | 
  | 
                else | 
| 158 | 
  | 
  | 
                        dcleanup(2);            /* remove definitions */ | 
| 159 | 
  | 
  | 
                freestr(f->ctx); | 
| 160 | 
  | 
  | 
        } | 
| 161 | 
  | 
  | 
        if (f->b != &unitxf) | 
| 162 | 
greg | 
2.14 | 
                free((void *)f->b); | 
| 163 | 
greg | 
2.2 | 
        if (f->f != NULL && f->f != &unitxf) | 
| 164 | 
greg | 
2.14 | 
                free((void *)f->f); | 
| 165 | 
  | 
  | 
        free((void *)f); | 
| 166 | 
greg | 
2.2 | 
        m->os = NULL; | 
| 167 | 
  | 
  | 
} | 
| 168 | 
  | 
  | 
 | 
| 169 | 
  | 
  | 
 | 
| 170 | 
schorsch | 
2.22 | 
extern int | 
| 171 | 
  | 
  | 
setfunc(                        /* set channels for function call */ | 
| 172 | 
  | 
  | 
        OBJREC  *m, | 
| 173 | 
  | 
  | 
        register RAY  *r | 
| 174 | 
  | 
  | 
) | 
| 175 | 
greg | 
1.1 | 
{ | 
| 176 | 
greg | 
2.9 | 
        static unsigned long  lastrno = ~0; | 
| 177 | 
greg | 
2.2 | 
        register MFUNC  *f; | 
| 178 | 
  | 
  | 
                                        /* get function */ | 
| 179 | 
  | 
  | 
        if ((f = (MFUNC *)m->os) == NULL) | 
| 180 | 
greg | 
2.14 | 
                objerror(m, CONSISTENCY, "setfunc called before getfunc"); | 
| 181 | 
greg | 
2.2 | 
                                        /* set evaluator context */ | 
| 182 | 
  | 
  | 
        setcontext(f->ctx); | 
| 183 | 
  | 
  | 
                                        /* check to see if matrix set */ | 
| 184 | 
greg | 
1.16 | 
        if (m == fobj && r->rno == lastrno) | 
| 185 | 
greg | 
1.17 | 
                return(0); | 
| 186 | 
greg | 
1.1 | 
        fobj = m; | 
| 187 | 
  | 
  | 
        fray = r; | 
| 188 | 
greg | 
1.13 | 
        if (r->rox != NULL) | 
| 189 | 
greg | 
2.2 | 
                if (f->b != &unitxf) { | 
| 190 | 
  | 
  | 
                        funcxf.sca = r->rox->b.sca * f->b->sca; | 
| 191 | 
  | 
  | 
                        multmat4(funcxf.xfm, r->rox->b.xfm, f->b->xfm); | 
| 192 | 
greg | 
1.13 | 
                } else | 
| 193 | 
schorsch | 
2.19 | 
                        funcxf = r->rox->b; | 
| 194 | 
greg | 
1.13 | 
        else | 
| 195 | 
schorsch | 
2.19 | 
                funcxf = *(f->b); | 
| 196 | 
greg | 
1.16 | 
        lastrno = r->rno; | 
| 197 | 
greg | 
1.1 | 
        eclock++;               /* notify expression evaluator */ | 
| 198 | 
greg | 
1.17 | 
        return(1); | 
| 199 | 
greg | 
1.1 | 
} | 
| 200 | 
  | 
  | 
 | 
| 201 | 
  | 
  | 
 | 
| 202 | 
schorsch | 
2.22 | 
extern void | 
| 203 | 
  | 
  | 
loadfunc(                       /* load definition file */ | 
| 204 | 
  | 
  | 
        char  *fname | 
| 205 | 
  | 
  | 
) | 
| 206 | 
greg | 
1.1 | 
{ | 
| 207 | 
  | 
  | 
        char  *ffname; | 
| 208 | 
  | 
  | 
 | 
| 209 | 
greg | 
2.18 | 
        if ((ffname = getpath(fname, getrlibpath(), R_OK)) == NULL) { | 
| 210 | 
greg | 
1.1 | 
                sprintf(errmsg, "cannot find function file \"%s\"", fname); | 
| 211 | 
  | 
  | 
                error(USER, errmsg); | 
| 212 | 
  | 
  | 
        } | 
| 213 | 
  | 
  | 
        fcompile(ffname); | 
| 214 | 
  | 
  | 
} | 
| 215 | 
  | 
  | 
 | 
| 216 | 
  | 
  | 
 | 
| 217 | 
greg | 
2.2 | 
static double | 
| 218 | 
greg | 
2.20 | 
l_arg(char *nm)                 /* return nth real argument */ | 
| 219 | 
greg | 
1.1 | 
{ | 
| 220 | 
  | 
  | 
        register int  n; | 
| 221 | 
  | 
  | 
 | 
| 222 | 
greg | 
2.7 | 
        if (fobj == NULL) | 
| 223 | 
  | 
  | 
                syntax("arg(n) used in constant expression"); | 
| 224 | 
  | 
  | 
 | 
| 225 | 
greg | 
1.1 | 
        n = argument(1) + .5;           /* round to integer */ | 
| 226 | 
  | 
  | 
 | 
| 227 | 
  | 
  | 
        if (n < 1) | 
| 228 | 
  | 
  | 
                return(fobj->oargs.nfargs); | 
| 229 | 
  | 
  | 
 | 
| 230 | 
  | 
  | 
        if (n > fobj->oargs.nfargs) { | 
| 231 | 
  | 
  | 
                sprintf(errmsg, "missing real argument %d", n); | 
| 232 | 
  | 
  | 
                objerror(fobj, USER, errmsg); | 
| 233 | 
  | 
  | 
        } | 
| 234 | 
  | 
  | 
        return(fobj->oargs.farg[n-1]); | 
| 235 | 
greg | 
1.19 | 
} | 
| 236 | 
  | 
  | 
 | 
| 237 | 
  | 
  | 
 | 
| 238 | 
greg | 
2.2 | 
static double | 
| 239 | 
greg | 
2.20 | 
l_erf(char *nm)                 /* error function */ | 
| 240 | 
greg | 
1.19 | 
{ | 
| 241 | 
  | 
  | 
        return(erf(argument(1))); | 
| 242 | 
  | 
  | 
} | 
| 243 | 
  | 
  | 
 | 
| 244 | 
  | 
  | 
 | 
| 245 | 
greg | 
2.2 | 
static double | 
| 246 | 
greg | 
2.20 | 
l_erfc(char *nm)                /* cumulative error function */ | 
| 247 | 
greg | 
1.19 | 
{ | 
| 248 | 
  | 
  | 
        return(erfc(argument(1))); | 
| 249 | 
greg | 
1.1 | 
} | 
| 250 | 
  | 
  | 
 | 
| 251 | 
  | 
  | 
 | 
| 252 | 
schorsch | 
2.22 | 
extern double | 
| 253 | 
  | 
  | 
chanvalue(                      /* return channel n to calcomp */ | 
| 254 | 
  | 
  | 
        register int  n | 
| 255 | 
  | 
  | 
) | 
| 256 | 
greg | 
1.1 | 
{ | 
| 257 | 
greg | 
2.7 | 
        if (fray == NULL) | 
| 258 | 
  | 
  | 
                syntax("ray parameter used in constant expression"); | 
| 259 | 
greg | 
1.1 | 
 | 
| 260 | 
greg | 
1.10 | 
        if (--n < 0) | 
| 261 | 
  | 
  | 
                goto badchan; | 
| 262 | 
greg | 
1.1 | 
 | 
| 263 | 
greg | 
2.17 | 
        if (n <= 2)                     /* ray direction */ | 
| 264 | 
greg | 
1.1 | 
 | 
| 265 | 
greg | 
1.12 | 
                return( (       fray->rdir[0]*funcxf.xfm[0][n] + | 
| 266 | 
  | 
  | 
                                fray->rdir[1]*funcxf.xfm[1][n] + | 
| 267 | 
  | 
  | 
                                fray->rdir[2]*funcxf.xfm[2][n]  ) | 
| 268 | 
  | 
  | 
                         / funcxf.sca ); | 
| 269 | 
greg | 
1.1 | 
 | 
| 270 | 
greg | 
2.17 | 
        if (n <= 5)                     /* surface normal */ | 
| 271 | 
greg | 
1.8 | 
 | 
| 272 | 
greg | 
1.12 | 
                return( (       fray->ron[0]*funcxf.xfm[0][n-3] + | 
| 273 | 
  | 
  | 
                                fray->ron[1]*funcxf.xfm[1][n-3] + | 
| 274 | 
  | 
  | 
                                fray->ron[2]*funcxf.xfm[2][n-3] ) | 
| 275 | 
  | 
  | 
                         / funcxf.sca ); | 
| 276 | 
greg | 
1.8 | 
 | 
| 277 | 
greg | 
2.17 | 
        if (n <= 8)                     /* intersection */ | 
| 278 | 
greg | 
1.8 | 
 | 
| 279 | 
greg | 
1.12 | 
                return( fray->rop[0]*funcxf.xfm[0][n-6] + | 
| 280 | 
  | 
  | 
                                fray->rop[1]*funcxf.xfm[1][n-6] + | 
| 281 | 
  | 
  | 
                                fray->rop[2]*funcxf.xfm[2][n-6] + | 
| 282 | 
  | 
  | 
                                             funcxf.xfm[3][n-6] ); | 
| 283 | 
greg | 
1.8 | 
 | 
| 284 | 
greg | 
2.13 | 
        if (n == 9)                     /* total distance */ | 
| 285 | 
  | 
  | 
                return(raydist(fray,PRIMARY) * funcxf.sca); | 
| 286 | 
greg | 
1.10 | 
 | 
| 287 | 
greg | 
1.18 | 
        if (n == 10)                    /* dot product (range [-1,1]) */ | 
| 288 | 
  | 
  | 
                return( fray->rod <= -1.0 ? -1.0 : | 
| 289 | 
  | 
  | 
                        fray->rod >= 1.0 ? 1.0 : | 
| 290 | 
  | 
  | 
                        fray->rod ); | 
| 291 | 
greg | 
1.10 | 
 | 
| 292 | 
greg | 
1.8 | 
        if (n == 11)                    /* scale */ | 
| 293 | 
greg | 
1.12 | 
                return(funcxf.sca); | 
| 294 | 
greg | 
1.8 | 
 | 
| 295 | 
greg | 
2.17 | 
        if (n <= 14)                    /* origin */ | 
| 296 | 
greg | 
1.12 | 
                return(funcxf.xfm[3][n-12]); | 
| 297 | 
greg | 
1.8 | 
 | 
| 298 | 
greg | 
2.17 | 
        if (n <= 17)                    /* i unit vector */ | 
| 299 | 
greg | 
1.12 | 
                return(funcxf.xfm[0][n-15] / funcxf.sca); | 
| 300 | 
greg | 
1.8 | 
 | 
| 301 | 
greg | 
2.17 | 
        if (n <= 20)                    /* j unit vector */ | 
| 302 | 
  | 
  | 
                return(funcxf.xfm[1][n-18] / funcxf.sca); | 
| 303 | 
greg | 
1.8 | 
 | 
| 304 | 
greg | 
2.17 | 
        if (n <= 23)                    /* k unit vector */ | 
| 305 | 
greg | 
1.12 | 
                return(funcxf.xfm[2][n-21] / funcxf.sca); | 
| 306 | 
greg | 
2.6 | 
 | 
| 307 | 
greg | 
2.17 | 
        if (n == 24)                    /* single ray (shadow) distance */ | 
| 308 | 
greg | 
2.13 | 
                return((fray->rot+raydist(fray->parent,SHADOW)) * funcxf.sca); | 
| 309 | 
greg | 
2.16 | 
 | 
| 310 | 
greg | 
2.17 | 
        if (n <= 26)                    /* local (u,v) coordinates */ | 
| 311 | 
  | 
  | 
                return(fray->uv[n-25]); | 
| 312 | 
greg | 
1.10 | 
badchan: | 
| 313 | 
  | 
  | 
        error(USER, "illegal channel number"); | 
| 314 | 
greg | 
2.16 | 
        return(0.0); | 
| 315 | 
greg | 
1.1 | 
} |