src/rt/func.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 *  func.c - interface to calcomp functions.
 */

/* ====================================================================
 * The Radiance Software License, Version 1.0
 *
 * Copyright (c) 1990 - 2002 The Regents of the University of California,
 * through Lawrence Berkeley National Laboratory.   All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *         notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *           if any, must include the following acknowledgment:
 *             "This product includes Radiance software
 *                 (http://radsite.lbl.gov/)
 *                 developed by the Lawrence Berkeley National Laboratory
 *               (http://www.lbl.gov/)."
 *       Alternately, this acknowledgment may appear in the software itself,
 *       if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
 *       and "The Regents of the University of California" must
 *       not be used to endorse or promote products derived from this
 *       software without prior written permission. For written
 *       permission, please contact [email protected].
 *
 * 5. Products derived from this software may not be called "Radiance",
 *       nor may "Radiance" appear in their name, without prior written
 *       permission of Lawrence Berkeley National Laboratory.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Lawrence Berkeley National Laboratory.   For more
 * information on Lawrence Berkeley National Laboratory, please see
 * <http://www.lbl.gov/>.
 */

#include  "ray.h"

#include  "otypes.h"

#include  "func.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 double  l_erf(), l_erfc(), l_arg();


MFUNC *
getfunc(m, ff, ef, dofwd)       /* get function for this modifier */
OBJREC  *m;
int  ff;
unsigned int  ef;
int  dofwd;
{
        static char  initfile[] = INITFILE;
        char  sbuf[MAXSTR];
        register char  **arg;
        register MFUNC  *f;
        int  ne, na;
        register int  i;
                                        /* check to see if done already */
        if ((f = (MFUNC *)m->os) != NULL)
                return(f);
        fobj = NULL; fray = NULL;
        if (initfile[0]) {              /* initialize on first call */
                esupport |= E_VARIABLE|E_FUNCTION|E_INCHAN|E_RCONST|E_REDEFW;
                esupport &= ~(E_OUTCHAN);
                setcontext("");
                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);
                funset("arg", 1, '=', l_arg);
                funset("erf", 1, ':', l_erf);
                funset("erfc", 1, ':', l_erfc);
                setnoisefuncs();
                setprismfuncs();
                loadfunc(initfile);
                initfile[0] = '\0';
        }
        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] == '.')
                setcontext(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 */
                setcontext(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);
        }
        curfunc = 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)
                                syntax("unexpected character");
                }
        if (ef)
                goto toofew;
        if (i <= ff)                    /* find transform args */
                i = ff+1;
        while (i < na && arg[i][0] != '-')
                i++;
        if (i == na)                    /* no transform */
                f->f = f->b = &unitxf;
        else {                          /* get transform */
                if ((f->b = (XF *)malloc(sizeof(XF))) == NULL)
                        goto memerr;
                if (invxf(f->b, na-i, arg+i) != na-i)
                        objerror(m, USER, "bad transform");
                if (f->b->sca < 0.0)
                        f->b->sca = -f->b->sca;
                if (dofwd) {                    /* do both transforms */
                        if ((f->f = (XF *)malloc(sizeof(XF))) == NULL)
                                goto memerr;
                        xf(f->f, na-i, arg+i);
                        if (f->f->sca < 0.0)
                                f->f->sca = -f->f->sca;
                }
        }
        m->os = (char *)f;
        return(f);
toofew:
        objerror(m, USER, "too few string arguments");
memerr:
        error(SYSTEM, "out of memory in getfunc");
}


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

        if ((f = (MFUNC *)m->os) == NULL)
                return;
        for (i = 0; f->ep[i] != NULL; i++)
                epfree(f->ep[i]);
        if (f->ctx[0]) {                        /* done with definitions */
                setcontext(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->b != &unitxf)
                free((void *)f->b);
        if (f->f != NULL && f->f != &unitxf)
                free((void *)f->f);
        free((void *)f);
        m->os = NULL;
}


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


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

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


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

        if (fobj == NULL)
                syntax("arg(n) used in constant expression");

        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()                         /* error function */
{
        extern double  erf();

        return(erf(argument(1)));
}


static double
l_erfc()                        /* cumulative error function */
{
        extern double  erfc();

        return(erfc(argument(1)));
}


double
chanvalue(n)                    /* return channel n to calcomp */
register int  n;
{
        if (fray == NULL)
                syntax("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 */

                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-15] / 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);
badchan:
        error(USER, "illegal channel number");
}
Revision:	2.14
Committed:	Sat Feb 22 02:07:28 2003 UTC (21 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.13:	+68 -14 lines
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.14	static const char RCSid[] = "$Id$";
3	greg	1.1	#endif
4			/*
5			* func.c - interface to calcomp functions.
6	greg	2.14	*/
7
8			/* ====================================================================
9			* The Radiance Software License, Version 1.0
10			*
11			* Copyright (c) 1990 - 2002 The Regents of the University of California,
12			* through Lawrence Berkeley National Laboratory. All rights reserved.
13			*
14			* Redistribution and use in source and binary forms, with or without
15			* modification, are permitted provided that the following conditions
16			* are met:
17			*
18			* 1. Redistributions of source code must retain the above copyright
19			* notice, this list of conditions and the following disclaimer.
20			*
21			* 2. Redistributions in binary form must reproduce the above copyright
22			* notice, this list of conditions and the following disclaimer in
23			* the documentation and/or other materials provided with the
24			* distribution.
25			*
26			* 3. The end-user documentation included with the redistribution,
27			* if any, must include the following acknowledgment:
28			* "This product includes Radiance software
29			* (http://radsite.lbl.gov/)
30			* developed by the Lawrence Berkeley National Laboratory
31			* (http://www.lbl.gov/)."
32			* Alternately, this acknowledgment may appear in the software itself,
33			* if and wherever such third-party acknowledgments normally appear.
34			*
35			* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
36			* and "The Regents of the University of California" must
37			* not be used to endorse or promote products derived from this
38			* software without prior written permission. For written
39			* permission, please contact [email protected].
40			*
41			* 5. Products derived from this software may not be called "Radiance",
42			* nor may "Radiance" appear in their name, without prior written
43			* permission of Lawrence Berkeley National Laboratory.
44			*
45			* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
46			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
47			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
48			* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
49			* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
51			* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
52			* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
53			* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
54			* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
55			* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56			* SUCH DAMAGE.
57			* ====================================================================
58	greg	1.1	*
59	greg	2.14	* This software consists of voluntary contributions made by many
60			* individuals on behalf of Lawrence Berkeley National Laboratory. For more
61			* information on Lawrence Berkeley National Laboratory, please see
62			* <http://www.lbl.gov/>.
63	greg	1.1	*/
64
65			#include "ray.h"
66
67			#include "otypes.h"
68
69	greg	2.2	#include "func.h"
70	greg	1.1
71	greg	2.2
72	greg	1.21	#define INITFILE "rayinit.cal"
73	greg	2.2	#define CALSUF ".cal"
74			#define LCALSUF 4
75	greg	2.10	char REFVNAME[] = "`FILE_REFCNT";
76	greg	1.21
77	greg	1.13	XF unitxf = { /* identity transform */
78	greg	2.8	{{1.0, 0.0, 0.0, 0.0},
79			{0.0, 1.0, 0.0, 0.0},
80			{0.0, 0.0, 1.0, 0.0},
81			{0.0, 0.0, 0.0, 1.0}},
82	greg	1.13	1.0
83			};
84
85	greg	1.12	XF funcxf; /* current transformation */
86			static OBJREC fobj = NULL; / current function object */
87			static RAY fray = NULL; / current function ray */
88	greg	1.1
89	greg	2.2	static double l_erf(), l_erfc(), l_arg();
90	greg	1.1
91	greg	2.2
92			MFUNC *
93			getfunc(m, ff, ef, dofwd) /* get function for this modifier */
94	greg	1.1	OBJREC *m;
95	greg	2.2	int ff;
96	greg	2.14	unsigned int ef;
97	greg	2.2	int dofwd;
98			{
99			static char initfile[] = INITFILE;
100			char sbuf[MAXSTR];
101			register char **arg;
102			register MFUNC *f;
103			int ne, na;
104			register int i;
105			/* check to see if done already */
106			if ((f = (MFUNC *)m->os) != NULL)
107			return(f);
108	greg	2.7	fobj = NULL; fray = NULL;
109	greg	2.2	if (initfile[0]) { /* initialize on first call */
110	greg	2.14	esupport \|= E_VARIABLE\|E_FUNCTION\|E_INCHAN\|E_RCONST\|E_REDEFW;
111			esupport &= ~(E_OUTCHAN);
112	greg	2.2	setcontext("");
113			scompile("Dx=$1;Dy=$2;Dz=$3;", NULL, 0);
114			scompile("Nx=$4;Ny=$5;Nz=$6;", NULL, 0);
115			scompile("Px=$7;Py=$8;Pz=$9;", NULL, 0);
116	greg	2.6	scompile("T=$10;Ts=$25;Rdot=$11;", NULL, 0);
117	greg	2.2	scompile("S=$12;Tx=$13;Ty=$14;Tz=$15;", NULL, 0);
118			scompile("Ix=$16;Iy=$17;Iz=$18;", NULL, 0);
119			scompile("Jx=$19;Jy=$20;Jz=$21;", NULL, 0);
120			scompile("Kx=$22;Ky=$23;Kz=$24;", NULL, 0);
121			funset("arg", 1, '=', l_arg);
122			funset("erf", 1, ':', l_erf);
123			funset("erfc", 1, ':', l_erfc);
124			setnoisefuncs();
125	greg	2.11	setprismfuncs();
126	greg	2.2	loadfunc(initfile);
127			initfile[0] = '\0';
128			}
129			if ((na = m->oargs.nsargs) <= ff)
130			goto toofew;
131			arg = m->oargs.sarg;
132			if ((f = (MFUNC *)calloc(1, sizeof(MFUNC))) == NULL)
133			goto memerr;
134			i = strlen(arg[ff]); /* set up context */
135			if (i == 1 && arg[ff][0] == '.')
136			setcontext(f->ctx = ""); /* "." means no file */
137			else {
138	greg	2.14	strcpy(sbuf,arg[ff]); /* file name is context */
139	greg	2.2	if (i > LCALSUF && !strcmp(sbuf+i-LCALSUF, CALSUF))
140			sbuf[i-LCALSUF] = '\0'; /* remove suffix */
141			setcontext(f->ctx = savestr(sbuf));
142			if (!vardefined(REFVNAME)) { /* file loaded? */
143	greg	2.5	loadfunc(arg[ff]);
144	greg	2.2	varset(REFVNAME, '=', 1.0);
145			} else /* reference_count++ */
146			varset(REFVNAME, '=', varvalue(REFVNAME)+1.0);
147			}
148			curfunc = NULL; /* parse expressions */
149			sprintf(sbuf, "%s \"%s\"", ofun[m->otype].funame, m->oname);
150			for (i=0, ne=0; ef && i < na; i++, ef>>=1)
151			if (ef & 1) { /* flagged as an expression? */
152			if (ne >= MAXEXPR)
153			objerror(m, INTERNAL, "too many expressions");
154			initstr(arg[i], sbuf, 0);
155			f->ep[ne++] = getE1();
156			if (nextc != EOF)
157			syntax("unexpected character");
158			}
159			if (ef)
160			goto toofew;
161			if (i <= ff) /* find transform args */
162			i = ff+1;
163			while (i < na && arg[i][0] != '-')
164			i++;
165			if (i == na) /* no transform */
166			f->f = f->b = &unitxf;
167			else { /* get transform */
168			if ((f->b = (XF *)malloc(sizeof(XF))) == NULL)
169	greg	2.3	goto memerr;
170	greg	2.2	if (invxf(f->b, na-i, arg+i) != na-i)
171			objerror(m, USER, "bad transform");
172			if (f->b->sca < 0.0)
173			f->b->sca = -f->b->sca;
174			if (dofwd) { /* do both transforms */
175			if ((f->f = (XF *)malloc(sizeof(XF))) == NULL)
176	greg	2.3	goto memerr;
177	greg	2.2	xf(f->f, na-i, arg+i);
178			if (f->f->sca < 0.0)
179			f->f->sca = -f->f->sca;
180			}
181			}
182			m->os = (char *)f;
183			return(f);
184			toofew:
185	greg	2.4	objerror(m, USER, "too few string arguments");
186	greg	2.2	memerr:
187			error(SYSTEM, "out of memory in getfunc");
188			}
189
190
191	greg	2.14	void
192	greg	2.2	freefunc(m) /* free memory associated with modifier */
193			OBJREC *m;
194			{
195			register MFUNC *f;
196			register int i;
197
198			if ((f = (MFUNC *)m->os) == NULL)
199			return;
200			for (i = 0; f->ep[i] != NULL; i++)
201			epfree(f->ep[i]);
202			if (f->ctx[0]) { /* done with definitions */
203			setcontext(f->ctx);
204			i = varvalue(REFVNAME)-.5; /* reference_count-- */
205			if (i > 0)
206			varset(REFVNAME, '=', (double)i);
207			else
208			dcleanup(2); /* remove definitions */
209			freestr(f->ctx);
210			}
211			if (f->b != &unitxf)
212	greg	2.14	free((void *)f->b);
213	greg	2.2	if (f->f != NULL && f->f != &unitxf)
214	greg	2.14	free((void *)f->f);
215			free((void *)f);
216	greg	2.2	m->os = NULL;
217			}
218
219
220	greg	2.14	int
221	greg	2.2	setfunc(m, r) /* set channels for function call */
222			OBJREC *m;
223	greg	1.1	register RAY *r;
224			{
225	greg	2.9	static unsigned long lastrno = ~0;
226	greg	2.2	register MFUNC *f;
227			/* get function */
228			if ((f = (MFUNC *)m->os) == NULL)
229	greg	2.14	objerror(m, CONSISTENCY, "setfunc called before getfunc");
230	greg	2.2	/* set evaluator context */
231			setcontext(f->ctx);
232			/* check to see if matrix set */
233	greg	1.16	if (m == fobj && r->rno == lastrno)
234	greg	1.17	return(0);
235	greg	1.1	fobj = m;
236			fray = r;
237	greg	1.13	if (r->rox != NULL)
238	greg	2.2	if (f->b != &unitxf) {
239			funcxf.sca = r->rox->b.sca * f->b->sca;
240			multmat4(funcxf.xfm, r->rox->b.xfm, f->b->xfm);
241	greg	1.13	} else
242			copystruct(&funcxf, &r->rox->b);
243			else
244	greg	2.2	copystruct(&funcxf, f->b);
245	greg	1.16	lastrno = r->rno;
246	greg	1.1	eclock++; /* notify expression evaluator */
247	greg	1.17	return(1);
248	greg	1.1	}
249
250
251	greg	2.14	void
252	greg	1.1	loadfunc(fname) /* load definition file */
253			char *fname;
254			{
255			char *ffname;
256
257	greg	2.12	if ((ffname = getpath(fname, getlibpath(), R_OK)) == NULL) {
258	greg	1.1	sprintf(errmsg, "cannot find function file \"%s\"", fname);
259			error(USER, errmsg);
260			}
261			fcompile(ffname);
262			}
263
264
265	greg	2.2	static double
266	greg	1.1	l_arg() /* return nth real argument */
267			{
268			register int n;
269
270	greg	2.7	if (fobj == NULL)
271			syntax("arg(n) used in constant expression");
272
273	greg	1.1	n = argument(1) + .5; /* round to integer */
274
275			if (n < 1)
276			return(fobj->oargs.nfargs);
277
278			if (n > fobj->oargs.nfargs) {
279			sprintf(errmsg, "missing real argument %d", n);
280			objerror(fobj, USER, errmsg);
281			}
282			return(fobj->oargs.farg[n-1]);
283	greg	1.19	}
284
285
286	greg	2.2	static double
287	greg	1.19	l_erf() /* error function */
288			{
289			extern double erf();
290
291			return(erf(argument(1)));
292			}
293
294
295	greg	2.2	static double
296	greg	1.19	l_erfc() /* cumulative error function */
297			{
298			extern double erfc();
299
300			return(erfc(argument(1)));
301	greg	1.1	}
302
303
304			double
305			chanvalue(n) /* return channel n to calcomp */
306			register int n;
307			{
308	greg	2.7	if (fray == NULL)
309			syntax("ray parameter used in constant expression");
310	greg	1.1
311	greg	1.10	if (--n < 0)
312			goto badchan;
313	greg	1.1
314	greg	1.8	if (n < 3) /* ray direction */
315	greg	1.1
316	greg	1.12	return( ( fray->rdir[0]*funcxf.xfm[0][n] +
317			fray->rdir[1]*funcxf.xfm[1][n] +
318			fray->rdir[2]*funcxf.xfm[2][n] )
319			/ funcxf.sca );
320	greg	1.1
321	greg	1.8	if (n < 6) /* surface normal */
322
323	greg	1.12	return( ( fray->ron[0]*funcxf.xfm[0][n-3] +
324			fray->ron[1]*funcxf.xfm[1][n-3] +
325			fray->ron[2]*funcxf.xfm[2][n-3] )
326			/ funcxf.sca );
327	greg	1.8
328			if (n < 9) /* intersection */
329
330	greg	1.12	return( fray->rop[0]*funcxf.xfm[0][n-6] +
331			fray->rop[1]*funcxf.xfm[1][n-6] +
332			fray->rop[2]*funcxf.xfm[2][n-6] +
333			funcxf.xfm[3][n-6] );
334	greg	1.8
335	greg	2.13	if (n == 9) /* total distance */
336			return(raydist(fray,PRIMARY) * funcxf.sca);
337	greg	1.10
338	greg	1.18	if (n == 10) /* dot product (range [-1,1]) */
339			return( fray->rod <= -1.0 ? -1.0 :
340			fray->rod >= 1.0 ? 1.0 :
341			fray->rod );
342	greg	1.10
343	greg	1.8	if (n == 11) /* scale */
344	greg	1.12	return(funcxf.sca);
345	greg	1.8
346			if (n < 15) /* origin */
347	greg	1.12	return(funcxf.xfm[3][n-12]);
348	greg	1.8
349			if (n < 18) /* i unit vector */
350	greg	1.12	return(funcxf.xfm[0][n-15] / funcxf.sca);
351	greg	1.8
352			if (n < 21) /* j unit vector */
353	greg	1.12	return(funcxf.xfm[1][n-15] / funcxf.sca);
354	greg	1.8
355			if (n < 24) /* k unit vector */
356	greg	1.12	return(funcxf.xfm[2][n-21] / funcxf.sca);
357	greg	2.6
358	greg	2.13	if (n == 24) /* single ray (shadow) distance */
359			return((fray->rot+raydist(fray->parent,SHADOW)) * funcxf.sca);
360	greg	1.10	badchan:
361			error(USER, "illegal channel number");
362	greg	1.1	}