src/rt/func.c

#ifndef lint
static const char       RCSid[] = "$Id: func.c,v 2.45 2025/11/13 18:57:20 greg Exp $";
#endif
/*
 *  func.c - interface to calcomp functions.
 */

#include "copyright.h"

#include  "ray.h"
#include  "paths.h"
#include  "otypes.h"
#include  "func.h"
#include <ctype.h>


#define  INITFILE       "rayinit.cal"
#define  CALSUF         ".cal"
#define  LCALSUF        4
char  REFVNAME[] = "`FILE_REFCNT";

XF  unitxf = {                  /* identity transform */
        {{1.0, 0.0, 0.0, 0.0},
        {0.0, 1.0, 0.0, 0.0},
        {0.0, 0.0, 1.0, 0.0},
        {0.0, 0.0, 0.0, 1.0}},
        1.0
};

XF  funcxf;                     /* current transformation */
static OBJREC  *fobj = NULL;    /* current function object */
static RAY  *fray = NULL;       /* current function ray */

static char  rayinitcal[] = INITFILE;

static double  l_erf(char *), l_erfc(char *), l_arg(char *);


void
initfunc(void)  /* initialize function evaluation */
{
        if (!rayinitcal[0])     /* already done? */
                return;
        esupport |= E_VARIABLE|E_FUNCTION|E_INCHAN|E_RCONST|E_REDEFW;
        esupport &= ~(E_OUTCHAN);
        calcontext("");
        scompile("Dx=$1;Dy=$2;Dz=$3;", NULL, 0);
        scompile("Nx=$4;Ny=$5;Nz=$6;", NULL, 0);
        scompile("Px=$7;Py=$8;Pz=$9;", NULL, 0);
        scompile("T=$10;Ts=$25;Rdot=$11;", NULL, 0);
        scompile("S=$12;Tx=$13;Ty=$14;Tz=$15;", NULL, 0);
        scompile("Ix=$16;Iy=$17;Iz=$18;", NULL, 0);
        scompile("Jx=$19;Jy=$20;Jz=$21;", NULL, 0);
        scompile("Kx=$22;Ky=$23;Kz=$24;", NULL, 0);
        scompile("Lu=$26;Lv=$27;", NULL, 0);
        funset("arg", 1, '=', l_arg);
        funset("erf", 1, ':', l_erf);
        funset("erfc", 1, ':', l_erfc);
        setnoisefuncs();
        setprismfuncs();
        loadfunc(rayinitcal);
        rayinitcal[0] = '\0';
        doptimize(1);           /* optimize definitions */
}


/* Set parameters for current evaluation */
void
set_eparams(const char *prms)
{
        static const char       *last_params = NULL;
        char                    vname[RMAXWORD];
        double                  value;
        char                    *cpd;
                                        /* check if already set */
        if (prms == NULL || !*prms)
                return;
        if (prms == last_params || (last_params != NULL &&
                                        !strcmp(prms, last_params)))
                return;
        last_params = prms;             /* XXX assumes static string */
                                        /* assign each variable */
        while (*prms) {
                if (isspace(*prms)) {
                        ++prms; continue;
                }
                if (!isalpha(*prms))
                        goto bad_params;
                cpd = vname;
                while (*prms && (*prms != '=') & !isspace(*prms)) {
                        if (!isid(*prms) | (cpd-vname >= RMAXWORD-1))
                                goto bad_params;
                        *cpd++ = *prms++;
                }
                *cpd = '\0';
                while (isspace(*prms)) prms++;
                if (*prms++ != '=')
                        goto bad_params;
                value = atof(prms);
                if ((prms = fskip((char *)prms)) == NULL)
                        goto bad_params;
                while (isspace(*prms)) prms++;
                prms += (*prms == ',') | (*prms == ';') | (*prms == ':');
                varset(vname, '=', value);
        }
        eclock++;               /* notify expression evaluator */
        return;
bad_params:
        sprintf(errmsg, "bad parameter list '%s'", last_params);
        error(USER, errmsg);
}


MFUNC *
getfunc(        /* get function for this modifier */
        OBJREC  *m,
        int  ff,
        unsigned int  ef,
        int  dofwd
)
{
        char  sbuf[MAXSTR];
        char  **arg;
        MFUNC  *f;
        int  ne, na;
        int  i;
                                        /* check to see if done already */
        if ((f = (MFUNC *)m->os) != NULL)
                return(f);
        fobj = NULL; fray = NULL;
        if ((na = m->oargs.nsargs) <= ff)
                goto toofew;
        arg = m->oargs.sarg;
        if ((f = (MFUNC *)calloc(1, sizeof(MFUNC))) == NULL)
                goto memerr;
        i = strlen(arg[ff]);                    /* set up context */
        if (i == 1 && arg[ff][0] == '.') {
                calcontext(f->ctx = "");        /* "." means no file */
        } else {
                strcpy(sbuf,arg[ff]);           /* file name is context */
                if (i > LCALSUF && !strcmp(sbuf+i-LCALSUF, CALSUF))
                        sbuf[i-LCALSUF] = '\0'; /* remove suffix */
                calcontext(f->ctx = savestr(sbuf));
                if (!vardefined(REFVNAME)) {    /* file loaded? */
                        loadfunc(arg[ff]);
                        varset(REFVNAME, '=', 1.0);
                } else                          /* reference_count++ */
                        varset(REFVNAME, '=', varvalue(REFVNAME)+1.0);
        }
        ecurfunc = NULL;                        /* parse expressions */
        sprintf(sbuf, "%s \"%s\"", ofun[m->otype].funame, m->oname);
        for (i=0, ne=0; ef && i < na; i++, ef>>=1)
                if (ef & 1) {                   /* flagged as an expression? */
                        if (ne >= MAXEXPR)
                                objerror(m, INTERNAL, "too many expressions");
                        initstr(arg[i], sbuf, 0);
                        f->ep[ne++] = getE1();
                        if (nextc != EOF)
                                esyntax("unexpected character");
                }
        if (ef)
                goto toofew;
        if (i <= ff)                    /* find transform args */
                i = ff+1;
        while (i < na && !isxfopt(arg[i]))
                i++;
        if (i == na) {                  /* no transform */
                f->fxp = f->bxp = &unitxf;
        } else {                        /* get transform */
                if ((f->bxp = (XF *)malloc(sizeof(XF))) == NULL)
                        goto memerr;
                if (invxf(f->bxp, na-i, arg+i) != na-i)
                        objerror(m, USER, "bad transform");
                if (f->bxp->sca < 0.0)
                        f->bxp->sca = -f->bxp->sca;
                if (dofwd) {                    /* do both transforms */
                        if ((f->fxp = (XF *)malloc(sizeof(XF))) == NULL)
                                goto memerr;
                        xf(f->fxp, na-i, arg+i);
                        if (f->fxp->sca < 0.0)
                                f->fxp->sca = -f->fxp->sca;
                }
        }
        m->os = (char *)f;
        return(f);
toofew:
        objerror(m, USER, "too few string arguments");
memerr:
        error(SYSTEM, "out of memory in getfunc");
        return NULL; /* pro forma return */
}


void
freefunc(                       /* free memory associated with modifier */
        OBJREC  *m
)
{
        MFUNC  *f;
        int  i;

        if ((f = (MFUNC *)m->os) == NULL)
                return;
        for (i = 0; f->ep[i] != NULL; i++)
                epfree(f->ep[i],1);
        if (f->ctx[0]) {                        /* done with definitions */
                calcontext(f->ctx);
                i = varvalue(REFVNAME)-.5;      /* reference_count-- */
                if (i > 0)
                        varset(REFVNAME, '=', (double)i);
                else
                        dcleanup(2);            /* remove definitions */
                freestr(f->ctx);
        }
        if (f->bxp != &unitxf)
                free((void *)f->bxp);
        if ((f->fxp != NULL) & (f->fxp != &unitxf))
                free((void *)f->fxp);
        free((void *)f);
        m->os = NULL;
}


int
setfunc(                        /* set channels for function call */
        OBJREC  *m,
        RAY     *r
)
{
        static RNUMBER  lastrno = ~0;
        MFUNC           *f;
                                        /* get function if any */
        if ((f = (MFUNC *)m->os) == NULL)
                objerror(m, CONSISTENCY, "setfunc called before getfunc");
                
        calcontext(f->ctx);             /* set evaluator context */
                                        /* check to see if matrix set */
        if ((m == fobj) & (r->rno == lastrno))
                return(0);
        fobj = m;
        fray = r;
        if (r->rox != NULL) {
                if (f->bxp != &unitxf) {
                        funcxf.sca = r->rox->b.sca * f->bxp->sca;
                        multmat4(funcxf.xfm, r->rox->b.xfm, f->bxp->xfm);
                } else
                        funcxf = r->rox->b;
        } else
                funcxf = *f->bxp;
        lastrno = r->rno;
        eclock++;               /* notify expression evaluator */
        return(1);
}


int
worldfunc(                      /* special function context sans object */
        const char      *ctx,
        RAY     *r
)
{
        static RNUMBER  lastrno = ~0;
                                        /* set evaluator context */
        calcontext((char *)ctx);
                                        /* check if ray already set */
        if ((fobj == NULL) & (r->rno == lastrno))
                return(0);
        fobj = NULL;
        fray = r;
        funcxf = unitxf;
        lastrno = r->rno;
        eclock++;               /* notify expression evaluator */
        return(1);
}


void
loadfunc(                       /* load definition file */
        char  *fname
)
{
        char  *ffname;

        if ((ffname = getpath(fname, getrlibpath(), R_OK)) == NULL) {
                sprintf(errmsg, "cannot find function file \"%s\"", fname);
                error(SYSTEM, errmsg);
        }
        fcompile(ffname);
}


static double
l_arg(char *nm)                 /* return nth real argument */
{
        int  n;

        if (fobj == NULL)
                error(USER,
                        "bad call to arg(n) - illegal constant in .cal file?");

        n = argument(1) + .5;           /* round to integer */

        if (n < 1)
                return(fobj->oargs.nfargs);

        if (n > fobj->oargs.nfargs) {
                sprintf(errmsg, "missing real argument %d", n);
                objerror(fobj, USER, errmsg);
        }
        return(fobj->oargs.farg[n-1]);
}


static double
l_erf(char *nm)                 /* error function */
{
        return(erf(argument(1)));
}


static double
l_erfc(char *nm)                /* cumulative error function */
{
        return(erfc(argument(1)));
}


double
chanvalue(                      /* return channel n to calcomp */
        int  n
)
{
        if (fray == NULL)
                esyntax("ray parameter used in constant expression");

        if (--n < 0)
                goto badchan;

        if (n < 3)                      /* ray direction */

                return( (       fray->rdir[0]*funcxf.xfm[0][n] +
                                fray->rdir[1]*funcxf.xfm[1][n] +
                                fray->rdir[2]*funcxf.xfm[2][n]  )
                         / funcxf.sca );

        if (n < 6)                      /* surface normal */

                return( (       fray->ron[0]*funcxf.xfm[0][n-3] +
                                fray->ron[1]*funcxf.xfm[1][n-3] +
                                fray->ron[2]*funcxf.xfm[2][n-3] )
                         / funcxf.sca );

        if (n < 9)                      /* intersection point */

                return( fray->rop[0]*funcxf.xfm[0][n-6] +
                                fray->rop[1]*funcxf.xfm[1][n-6] +
                                fray->rop[2]*funcxf.xfm[2][n-6] +
                                             funcxf.xfm[3][n-6] );

        if (n == 9)                     /* total distance */
                return(raydist(fray,PRIMARY) * funcxf.sca);

        if (n == 10)                    /* dot product (range [-1,1]) */
                return( fray->rod <= -1.0 ? -1.0 :
                        fray->rod >= 1.0 ? 1.0 :
                        fray->rod );

        if (n == 11)                    /* scale */
                return(funcxf.sca);

        if (n < 15)                     /* origin */
                return(funcxf.xfm[3][n-12]);

        if (n < 18)                     /* i unit vector */
                return(funcxf.xfm[0][n-15] / funcxf.sca);

        if (n < 21)                     /* j unit vector */
                return(funcxf.xfm[1][n-18] / funcxf.sca);

        if (n < 24)                     /* k unit vector */
                return(funcxf.xfm[2][n-21] / funcxf.sca);

        if (n == 24)                    /* single ray (shadow) distance */
                return((fray->rot+raydist(fray->parent,SHADOW)) * funcxf.sca);

        if (n < 27)                     /* local (u,v) coordinates */
                return(fray->uv[n-25]);
badchan:
        error(USER, "illegal channel number");
        return(0.0);
}
Revision:	2.46
Committed:	Sat Dec 6 04:13:14 2025 UTC (2 weeks, 1 day ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 2.45:	+2 -2 lines
Log Message:	perf: Removed unnecessary call to doptimize(1) after every file load
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.46	static const char RCSid[] = "$Id: func.c,v 2.45 2025/11/13 18:57:20 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			#include "ray.h"
11	greg	2.21	#include "paths.h"
12	greg	1.1	#include "otypes.h"
13	greg	2.2	#include "func.h"
14	greg	2.30	#include <ctype.h>
15	greg	1.1
16	greg	2.2
17	greg	1.21	#define INITFILE "rayinit.cal"
18	greg	2.2	#define CALSUF ".cal"
19			#define LCALSUF 4
20	greg	2.10	char REFVNAME[] = "`FILE_REFCNT";
21	greg	1.21
22	greg	1.13	XF unitxf = { /* identity transform */
23	greg	2.8	{{1.0, 0.0, 0.0, 0.0},
24			{0.0, 1.0, 0.0, 0.0},
25			{0.0, 0.0, 1.0, 0.0},
26			{0.0, 0.0, 0.0, 1.0}},
27	greg	1.13	1.0
28			};
29
30	greg	1.12	XF funcxf; /* current transformation */
31			static OBJREC fobj = NULL; / current function object */
32			static RAY fray = NULL; / current function ray */
33	greg	1.1
34	greg	2.26	static char rayinitcal[] = INITFILE;
35
36	greg	2.20	static double l_erf(char ), l_erfc(char ), l_arg(char *);
37	greg	1.1
38	greg	2.2
39	greg	2.26	void
40	greg	2.32	initfunc(void) /* initialize function evaluation */
41	greg	2.26	{
42			if (!rayinitcal[0]) /* already done? */
43			return;
44			esupport \|= E_VARIABLE\|E_FUNCTION\|E_INCHAN\|E_RCONST\|E_REDEFW;
45			esupport &= ~(E_OUTCHAN);
46	greg	2.39	calcontext("");
47	greg	2.26	scompile("Dx=$1;Dy=$2;Dz=$3;", NULL, 0);
48			scompile("Nx=$4;Ny=$5;Nz=$6;", NULL, 0);
49			scompile("Px=$7;Py=$8;Pz=$9;", NULL, 0);
50			scompile("T=$10;Ts=$25;Rdot=$11;", NULL, 0);
51			scompile("S=$12;Tx=$13;Ty=$14;Tz=$15;", NULL, 0);
52			scompile("Ix=$16;Iy=$17;Iz=$18;", NULL, 0);
53			scompile("Jx=$19;Jy=$20;Jz=$21;", NULL, 0);
54			scompile("Kx=$22;Ky=$23;Kz=$24;", NULL, 0);
55			scompile("Lu=$26;Lv=$27;", NULL, 0);
56			funset("arg", 1, '=', l_arg);
57			funset("erf", 1, ':', l_erf);
58			funset("erfc", 1, ':', l_erfc);
59			setnoisefuncs();
60			setprismfuncs();
61			loadfunc(rayinitcal);
62			rayinitcal[0] = '\0';
63	greg	2.46	doptimize(1); /* optimize definitions */
64	greg	2.26	}
65
66
67	greg	2.29	/* Set parameters for current evaluation */
68			void
69	greg	2.42	set_eparams(const char *prms)
70	greg	2.29	{
71	greg	2.42	static const char *last_params = NULL;
72			char vname[RMAXWORD];
73			double value;
74			char *cpd;
75	greg	2.29	/* check if already set */
76	greg	2.32	if (prms == NULL \|\| !*prms)
77	greg	2.29	return;
78	greg	2.35	if (prms == last_params \|\| (last_params != NULL &&
79			!strcmp(prms, last_params)))
80	greg	2.29	return;
81	greg	2.35	last_params = prms; /* XXX assumes static string */
82	greg	2.32	/* assign each variable */
83	greg	2.29	while (*prms) {
84			if (isspace(*prms)) {
85			++prms; continue;
86			}
87			if (!isalpha(*prms))
88			goto bad_params;
89			cpd = vname;
90			while (prms && (prms != '=') & !isspace(*prms)) {
91	greg	2.31	if (!isid(*prms) \| (cpd-vname >= RMAXWORD-1))
92	greg	2.29	goto bad_params;
93			cpd++ = prms++;
94			}
95			*cpd = '\0';
96			while (isspace(*prms)) prms++;
97			if (*prms++ != '=')
98			goto bad_params;
99			value = atof(prms);
100	greg	2.42	if ((prms = fskip((char *)prms)) == NULL)
101	greg	2.29	goto bad_params;
102			while (isspace(*prms)) prms++;
103	greg	2.37	prms += (prms == ',') \| (prms == ';') \| (*prms == ':');
104	greg	2.29	varset(vname, '=', value);
105			}
106	greg	2.34	eclock++; /* notify expression evaluator */
107	greg	2.29	return;
108			bad_params:
109			sprintf(errmsg, "bad parameter list '%s'", last_params);
110			error(USER, errmsg);
111			}
112
113
114	greg	2.25	MFUNC *
115	schorsch	2.22	getfunc( /* get function for this modifier */
116			OBJREC *m,
117			int ff,
118			unsigned int ef,
119			int dofwd
120			)
121	greg	2.2	{
122			char sbuf[MAXSTR];
123	greg	2.25	char **arg;
124			MFUNC *f;
125	greg	2.2	int ne, na;
126	greg	2.25	int i;
127	greg	2.2	/* check to see if done already */
128			if ((f = (MFUNC *)m->os) != NULL)
129			return(f);
130	greg	2.7	fobj = NULL; fray = NULL;
131	greg	2.2	if ((na = m->oargs.nsargs) <= ff)
132			goto toofew;
133			arg = m->oargs.sarg;
134			if ((f = (MFUNC *)calloc(1, sizeof(MFUNC))) == NULL)
135			goto memerr;
136			i = strlen(arg[ff]); /* set up context */
137	greg	2.26	if (i == 1 && arg[ff][0] == '.') {
138	greg	2.39	calcontext(f->ctx = ""); /* "." means no file */
139	greg	2.26	} else {
140	greg	2.14	strcpy(sbuf,arg[ff]); /* file name is context */
141	greg	2.2	if (i > LCALSUF && !strcmp(sbuf+i-LCALSUF, CALSUF))
142			sbuf[i-LCALSUF] = '\0'; /* remove suffix */
143	greg	2.39	calcontext(f->ctx = savestr(sbuf));
144	greg	2.2	if (!vardefined(REFVNAME)) { /* file loaded? */
145	greg	2.5	loadfunc(arg[ff]);
146	greg	2.2	varset(REFVNAME, '=', 1.0);
147			} else /* reference_count++ */
148			varset(REFVNAME, '=', varvalue(REFVNAME)+1.0);
149			}
150	greg	2.41	ecurfunc = NULL; /* parse expressions */
151	greg	2.2	sprintf(sbuf, "%s \"%s\"", ofun[m->otype].funame, m->oname);
152			for (i=0, ne=0; ef && i < na; i++, ef>>=1)
153			if (ef & 1) { /* flagged as an expression? */
154			if (ne >= MAXEXPR)
155			objerror(m, INTERNAL, "too many expressions");
156			initstr(arg[i], sbuf, 0);
157			f->ep[ne++] = getE1();
158			if (nextc != EOF)
159	greg	2.41	esyntax("unexpected character");
160	greg	2.2	}
161			if (ef)
162			goto toofew;
163			if (i <= ff) /* find transform args */
164			i = ff+1;
165	greg	2.44	while (i < na && !isxfopt(arg[i]))
166	greg	2.2	i++;
167	greg	2.26	if (i == na) { /* no transform */
168			f->fxp = f->bxp = &unitxf;
169			} else { /* get transform */
170			if ((f->bxp = (XF *)malloc(sizeof(XF))) == NULL)
171	greg	2.3	goto memerr;
172	greg	2.26	if (invxf(f->bxp, na-i, arg+i) != na-i)
173	greg	2.2	objerror(m, USER, "bad transform");
174	greg	2.26	if (f->bxp->sca < 0.0)
175			f->bxp->sca = -f->bxp->sca;
176	greg	2.2	if (dofwd) { /* do both transforms */
177	greg	2.26	if ((f->fxp = (XF *)malloc(sizeof(XF))) == NULL)
178	greg	2.3	goto memerr;
179	greg	2.26	xf(f->fxp, na-i, arg+i);
180			if (f->fxp->sca < 0.0)
181			f->fxp->sca = -f->fxp->sca;
182	greg	2.2	}
183			}
184			m->os = (char *)f;
185			return(f);
186			toofew:
187	greg	2.4	objerror(m, USER, "too few string arguments");
188	greg	2.2	memerr:
189			error(SYSTEM, "out of memory in getfunc");
190	schorsch	2.22	return NULL; /* pro forma return */
191	greg	2.2	}
192
193
194	greg	2.25	void
195	schorsch	2.22	freefunc( /* free memory associated with modifier */
196			OBJREC *m
197			)
198	greg	2.2	{
199	greg	2.25	MFUNC *f;
200			int i;
201	greg	2.2
202			if ((f = (MFUNC *)m->os) == NULL)
203			return;
204			for (i = 0; f->ep[i] != NULL; i++)
205	greg	2.40	epfree(f->ep[i],1);
206	greg	2.2	if (f->ctx[0]) { /* done with definitions */
207	greg	2.39	calcontext(f->ctx);
208	greg	2.2	i = varvalue(REFVNAME)-.5; /* reference_count-- */
209			if (i > 0)
210			varset(REFVNAME, '=', (double)i);
211			else
212			dcleanup(2); /* remove definitions */
213			freestr(f->ctx);
214			}
215	greg	2.26	if (f->bxp != &unitxf)
216			free((void *)f->bxp);
217			if ((f->fxp != NULL) & (f->fxp != &unitxf))
218			free((void *)f->fxp);
219	greg	2.14	free((void *)f);
220	greg	2.2	m->os = NULL;
221			}
222
223
224	greg	2.25	int
225	schorsch	2.22	setfunc( /* set channels for function call */
226	greg	2.26	OBJREC *m,
227			RAY *r
228	schorsch	2.22	)
229	greg	1.1	{
230	greg	2.26	static RNUMBER lastrno = ~0;
231			MFUNC *f;
232	greg	2.25	/* get function if any */
233	greg	2.26	if ((f = (MFUNC *)m->os) == NULL)
234			objerror(m, CONSISTENCY, "setfunc called before getfunc");
235
236	greg	2.39	calcontext(f->ctx); /* set evaluator context */
237	greg	2.2	/* check to see if matrix set */
238	greg	2.25	if ((m == fobj) & (r->rno == lastrno))
239	greg	1.17	return(0);
240	greg	1.1	fobj = m;
241			fray = r;
242	greg	2.26	if (r->rox != NULL) {
243			if (f->bxp != &unitxf) {
244			funcxf.sca = r->rox->b.sca * f->bxp->sca;
245			multmat4(funcxf.xfm, r->rox->b.xfm, f->bxp->xfm);
246	greg	1.13	} else
247	schorsch	2.19	funcxf = r->rox->b;
248	greg	2.26	} else
249			funcxf = *f->bxp;
250			lastrno = r->rno;
251			eclock++; /* notify expression evaluator */
252			return(1);
253			}
254
255
256			int
257			worldfunc( /* special function context sans object */
258	greg	2.42	const char *ctx,
259	greg	2.26	RAY *r
260			)
261			{
262			static RNUMBER lastrno = ~0;
263			/* set evaluator context */
264	greg	2.42	calcontext((char *)ctx);
265	greg	2.26	/* check if ray already set */
266			if ((fobj == NULL) & (r->rno == lastrno))
267			return(0);
268			fobj = NULL;
269			fray = r;
270			funcxf = unitxf;
271	greg	1.16	lastrno = r->rno;
272	greg	1.1	eclock++; /* notify expression evaluator */
273	greg	1.17	return(1);
274	greg	1.1	}
275
276
277	greg	2.25	void
278	schorsch	2.22	loadfunc( /* load definition file */
279			char *fname
280			)
281	greg	1.1	{
282			char *ffname;
283
284	greg	2.18	if ((ffname = getpath(fname, getrlibpath(), R_OK)) == NULL) {
285	greg	1.1	sprintf(errmsg, "cannot find function file \"%s\"", fname);
286	greg	2.31	error(SYSTEM, errmsg);
287	greg	1.1	}
288			fcompile(ffname);
289			}
290
291
292	greg	2.2	static double
293	greg	2.20	l_arg(char nm) / return nth real argument */
294	greg	1.1	{
295	greg	2.25	int n;
296	greg	1.1
297	greg	2.7	if (fobj == NULL)
298	greg	2.38	error(USER,
299			"bad call to arg(n) - illegal constant in .cal file?");
300	greg	2.7
301	greg	1.1	n = argument(1) + .5; /* round to integer */
302
303			if (n < 1)
304			return(fobj->oargs.nfargs);
305
306			if (n > fobj->oargs.nfargs) {
307			sprintf(errmsg, "missing real argument %d", n);
308			objerror(fobj, USER, errmsg);
309			}
310			return(fobj->oargs.farg[n-1]);
311	greg	1.19	}
312
313
314	greg	2.2	static double
315	greg	2.20	l_erf(char nm) / error function */
316	greg	1.19	{
317			return(erf(argument(1)));
318			}
319
320
321	greg	2.2	static double
322	greg	2.20	l_erfc(char nm) / cumulative error function */
323	greg	1.19	{
324			return(erfc(argument(1)));
325	greg	1.1	}
326
327
328	greg	2.25	double
329	schorsch	2.22	chanvalue( /* return channel n to calcomp */
330	greg	2.25	int n
331	schorsch	2.22	)
332	greg	1.1	{
333	greg	2.7	if (fray == NULL)
334	greg	2.41	esyntax("ray parameter used in constant expression");
335	greg	1.1
336	greg	1.10	if (--n < 0)
337			goto badchan;
338	greg	1.1
339	greg	2.45	if (n < 3) /* ray direction */
340	greg	1.1
341	greg	1.12	return( ( fray->rdir[0]*funcxf.xfm[0][n] +
342			fray->rdir[1]*funcxf.xfm[1][n] +
343			fray->rdir[2]*funcxf.xfm[2][n] )
344			/ funcxf.sca );
345	greg	1.1
346	greg	2.45	if (n < 6) /* surface normal */
347	greg	1.8
348	greg	1.12	return( ( fray->ron[0]*funcxf.xfm[0][n-3] +
349			fray->ron[1]*funcxf.xfm[1][n-3] +
350			fray->ron[2]*funcxf.xfm[2][n-3] )
351			/ funcxf.sca );
352	greg	1.8
353	greg	2.45	if (n < 9) /* intersection point */
354	greg	1.8
355	greg	1.12	return( fray->rop[0]*funcxf.xfm[0][n-6] +
356			fray->rop[1]*funcxf.xfm[1][n-6] +
357			fray->rop[2]*funcxf.xfm[2][n-6] +
358			funcxf.xfm[3][n-6] );
359	greg	1.8
360	greg	2.13	if (n == 9) /* total distance */
361			return(raydist(fray,PRIMARY) * funcxf.sca);
362	greg	1.10
363	greg	1.18	if (n == 10) /* dot product (range [-1,1]) */
364			return( fray->rod <= -1.0 ? -1.0 :
365			fray->rod >= 1.0 ? 1.0 :
366			fray->rod );
367	greg	1.10
368	greg	1.8	if (n == 11) /* scale */
369	greg	1.12	return(funcxf.sca);
370	greg	1.8
371	greg	2.45	if (n < 15) /* origin */
372	greg	1.12	return(funcxf.xfm[3][n-12]);
373	greg	1.8
374	greg	2.45	if (n < 18) /* i unit vector */
375	greg	1.12	return(funcxf.xfm[0][n-15] / funcxf.sca);
376	greg	1.8
377	greg	2.45	if (n < 21) /* j unit vector */
378	greg	2.17	return(funcxf.xfm[1][n-18] / funcxf.sca);
379	greg	1.8
380	greg	2.45	if (n < 24) /* k unit vector */
381	greg	1.12	return(funcxf.xfm[2][n-21] / funcxf.sca);
382	greg	2.6
383	greg	2.17	if (n == 24) /* single ray (shadow) distance */
384	greg	2.13	return((fray->rot+raydist(fray->parent,SHADOW)) * funcxf.sca);
385	greg	2.16
386	greg	2.45	if (n < 27) /* local (u,v) coordinates */
387	greg	2.17	return(fray->uv[n-25]);
388	greg	1.10	badchan:
389			error(USER, "illegal channel number");
390	greg	2.16	return(0.0);
391	greg	1.1	}