src/rt/func.c

#ifndef lint
static const char       RCSid[] = "$Id: func.c,v 2.32 2016/04/27 21:11:32 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);
        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);
        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';
}


/* Set parameters for current evaluation */
void
set_eparams(char *prms)
{
        static char     *last_params;
        static int      lplen = 0;
        int             len;
        char            vname[RMAXWORD];
        double          value;
        char            *cpd;
                                        /* check if already set */
        if (prms == NULL || !*prms)
                return;
        if (lplen && !strcmp(prms, last_params))
                return;
        len = strlen(prms);             /* record new settings */
        if ((lplen != 0) & (lplen <= len)) {
                free(last_params);
                lplen = 0;
        }
        if (!lplen) {
                lplen = len + 100;
                last_params = (char *)malloc(lplen);
                if (last_params == NULL)
                        error(SYSTEM, "out of memory in set_eparams()");
        }
        strcpy(last_params, prms);
                                        /* 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(prms)) == NULL)
                        goto bad_params;
                while (isspace(*prms)) prms++;
                prms += (*prms == ',') | (*prms == ';');
                varset(vname, '=', value);
        }
        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 (rayinitcal[0])              /* initialize on first call */
                initfunc();
        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->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]);
        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->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");
                
        setcontext(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 */
        char    *ctx,
        RAY     *r
)
{
        static RNUMBER  lastrno = ~0;

        if (rayinitcal[0])              /* initialize on first call */
                initfunc();
                                        /* set evaluator context */
        setcontext(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(INTERNAL, "arg(n) called without a modifier context");

        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)
                syntax("ray parameter used in constant expression");

        if (--n < 0)
                goto badchan;

        if (n <= 2)                     /* 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 <= 5)                     /* 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 <= 8) {                   /* intersection point */
                if (fray->rot >= FHUGE)
                        return(0.0);    /* XXX should be runtime error? */

                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 <= 14)                    /* origin */
                return(funcxf.xfm[3][n-12]);

        if (n <= 17)                    /* i unit vector */
                return(funcxf.xfm[0][n-15] / funcxf.sca);

        if (n <= 20)                    /* j unit vector */
                return(funcxf.xfm[1][n-18] / funcxf.sca);

        if (n <= 23)                    /* 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 <= 26)                    /* local (u,v) coordinates */
                return(fray->uv[n-25]);
badchan:
        error(USER, "illegal channel number");
        return(0.0);
}
Revision:	2.33
Committed:	Sat May 13 00:09:53 2017 UTC (7 years ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.32:	+1 -3 lines
Log Message:	Removed unnecessary test
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.33	static const char RCSid[] = "$Id: func.c,v 2.32 2016/04/27 21:11:32 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			setcontext("");
47			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			}
64
65
66	greg	2.29	/* Set parameters for current evaluation */
67			void
68			set_eparams(char *prms)
69			{
70	greg	2.32	static char *last_params;
71			static int lplen = 0;
72			int len;
73	greg	2.29	char vname[RMAXWORD];
74			double value;
75			char *cpd;
76			/* check if already set */
77	greg	2.32	if (prms == NULL \|\| !*prms)
78	greg	2.29	return;
79	greg	2.32	if (lplen && !strcmp(prms, last_params))
80	greg	2.29	return;
81	greg	2.32	len = strlen(prms); /* record new settings */
82			if ((lplen != 0) & (lplen <= len)) {
83			free(last_params);
84			lplen = 0;
85			}
86			if (!lplen) {
87			lplen = len + 100;
88			last_params = (char *)malloc(lplen);
89			if (last_params == NULL)
90			error(SYSTEM, "out of memory in set_eparams()");
91			}
92			strcpy(last_params, prms);
93			/* assign each variable */
94	greg	2.29	while (*prms) {
95			if (isspace(*prms)) {
96			++prms; continue;
97			}
98			if (!isalpha(*prms))
99			goto bad_params;
100			cpd = vname;
101			while (prms && (prms != '=') & !isspace(*prms)) {
102	greg	2.31	if (!isid(*prms) \| (cpd-vname >= RMAXWORD-1))
103	greg	2.29	goto bad_params;
104			cpd++ = prms++;
105			}
106			*cpd = '\0';
107			while (isspace(*prms)) prms++;
108			if (*prms++ != '=')
109			goto bad_params;
110			value = atof(prms);
111			if ((prms = fskip(prms)) == NULL)
112			goto bad_params;
113			while (isspace(*prms)) prms++;
114			prms += (prms == ',') \| (prms == ';');
115			varset(vname, '=', value);
116			}
117			return;
118			bad_params:
119			sprintf(errmsg, "bad parameter list '%s'", last_params);
120			error(USER, errmsg);
121			}
122
123
124	greg	2.25	MFUNC *
125	schorsch	2.22	getfunc( /* get function for this modifier */
126			OBJREC *m,
127			int ff,
128			unsigned int ef,
129			int dofwd
130			)
131	greg	2.2	{
132			char sbuf[MAXSTR];
133	greg	2.25	char **arg;
134			MFUNC *f;
135	greg	2.2	int ne, na;
136	greg	2.25	int i;
137	greg	2.2	/* check to see if done already */
138			if ((f = (MFUNC *)m->os) != NULL)
139			return(f);
140	greg	2.7	fobj = NULL; fray = NULL;
141	greg	2.26	if (rayinitcal[0]) /* initialize on first call */
142			initfunc();
143	greg	2.2	if ((na = m->oargs.nsargs) <= ff)
144			goto toofew;
145			arg = m->oargs.sarg;
146			if ((f = (MFUNC *)calloc(1, sizeof(MFUNC))) == NULL)
147			goto memerr;
148			i = strlen(arg[ff]); /* set up context */
149	greg	2.26	if (i == 1 && arg[ff][0] == '.') {
150	greg	2.2	setcontext(f->ctx = ""); /* "." means no file */
151	greg	2.26	} else {
152	greg	2.14	strcpy(sbuf,arg[ff]); /* file name is context */
153	greg	2.2	if (i > LCALSUF && !strcmp(sbuf+i-LCALSUF, CALSUF))
154			sbuf[i-LCALSUF] = '\0'; /* remove suffix */
155			setcontext(f->ctx = savestr(sbuf));
156			if (!vardefined(REFVNAME)) { /* file loaded? */
157	greg	2.5	loadfunc(arg[ff]);
158	greg	2.2	varset(REFVNAME, '=', 1.0);
159			} else /* reference_count++ */
160			varset(REFVNAME, '=', varvalue(REFVNAME)+1.0);
161			}
162			curfunc = NULL; /* parse expressions */
163			sprintf(sbuf, "%s \"%s\"", ofun[m->otype].funame, m->oname);
164			for (i=0, ne=0; ef && i < na; i++, ef>>=1)
165			if (ef & 1) { /* flagged as an expression? */
166			if (ne >= MAXEXPR)
167			objerror(m, INTERNAL, "too many expressions");
168			initstr(arg[i], sbuf, 0);
169			f->ep[ne++] = getE1();
170			if (nextc != EOF)
171			syntax("unexpected character");
172			}
173			if (ef)
174			goto toofew;
175			if (i <= ff) /* find transform args */
176			i = ff+1;
177			while (i < na && arg[i][0] != '-')
178			i++;
179	greg	2.26	if (i == na) { /* no transform */
180			f->fxp = f->bxp = &unitxf;
181			} else { /* get transform */
182			if ((f->bxp = (XF *)malloc(sizeof(XF))) == NULL)
183	greg	2.3	goto memerr;
184	greg	2.26	if (invxf(f->bxp, na-i, arg+i) != na-i)
185	greg	2.2	objerror(m, USER, "bad transform");
186	greg	2.26	if (f->bxp->sca < 0.0)
187			f->bxp->sca = -f->bxp->sca;
188	greg	2.2	if (dofwd) { /* do both transforms */
189	greg	2.26	if ((f->fxp = (XF *)malloc(sizeof(XF))) == NULL)
190	greg	2.3	goto memerr;
191	greg	2.26	xf(f->fxp, na-i, arg+i);
192			if (f->fxp->sca < 0.0)
193			f->fxp->sca = -f->fxp->sca;
194	greg	2.2	}
195			}
196			m->os = (char *)f;
197			return(f);
198			toofew:
199	greg	2.4	objerror(m, USER, "too few string arguments");
200	greg	2.2	memerr:
201			error(SYSTEM, "out of memory in getfunc");
202	schorsch	2.22	return NULL; /* pro forma return */
203	greg	2.2	}
204
205
206	greg	2.25	void
207	schorsch	2.22	freefunc( /* free memory associated with modifier */
208			OBJREC *m
209			)
210	greg	2.2	{
211	greg	2.25	MFUNC *f;
212			int i;
213	greg	2.2
214			if ((f = (MFUNC *)m->os) == NULL)
215			return;
216			for (i = 0; f->ep[i] != NULL; i++)
217			epfree(f->ep[i]);
218			if (f->ctx[0]) { /* done with definitions */
219			setcontext(f->ctx);
220			i = varvalue(REFVNAME)-.5; /* reference_count-- */
221			if (i > 0)
222			varset(REFVNAME, '=', (double)i);
223			else
224			dcleanup(2); /* remove definitions */
225			freestr(f->ctx);
226			}
227	greg	2.26	if (f->bxp != &unitxf)
228			free((void *)f->bxp);
229			if ((f->fxp != NULL) & (f->fxp != &unitxf))
230			free((void *)f->fxp);
231	greg	2.14	free((void *)f);
232	greg	2.2	m->os = NULL;
233			}
234
235
236	greg	2.25	int
237	schorsch	2.22	setfunc( /* set channels for function call */
238	greg	2.26	OBJREC *m,
239			RAY *r
240	schorsch	2.22	)
241	greg	1.1	{
242	greg	2.26	static RNUMBER lastrno = ~0;
243			MFUNC *f;
244	greg	2.25	/* get function if any */
245	greg	2.26	if ((f = (MFUNC *)m->os) == NULL)
246			objerror(m, CONSISTENCY, "setfunc called before getfunc");
247
248			setcontext(f->ctx); /* set evaluator context */
249	greg	2.2	/* check to see if matrix set */
250	greg	2.25	if ((m == fobj) & (r->rno == lastrno))
251	greg	1.17	return(0);
252	greg	1.1	fobj = m;
253			fray = r;
254	greg	2.26	if (r->rox != NULL) {
255			if (f->bxp != &unitxf) {
256			funcxf.sca = r->rox->b.sca * f->bxp->sca;
257			multmat4(funcxf.xfm, r->rox->b.xfm, f->bxp->xfm);
258	greg	1.13	} else
259	schorsch	2.19	funcxf = r->rox->b;
260	greg	2.26	} else
261			funcxf = *f->bxp;
262			lastrno = r->rno;
263			eclock++; /* notify expression evaluator */
264			return(1);
265			}
266
267
268			int
269			worldfunc( /* special function context sans object */
270			char *ctx,
271			RAY *r
272			)
273			{
274			static RNUMBER lastrno = ~0;
275	greg	2.27
276			if (rayinitcal[0]) /* initialize on first call */
277			initfunc();
278	greg	2.26	/* set evaluator context */
279			setcontext(ctx);
280			/* check if ray already set */
281			if ((fobj == NULL) & (r->rno == lastrno))
282			return(0);
283			fobj = NULL;
284			fray = r;
285			funcxf = unitxf;
286	greg	1.16	lastrno = r->rno;
287	greg	1.1	eclock++; /* notify expression evaluator */
288	greg	1.17	return(1);
289	greg	1.1	}
290
291
292	greg	2.25	void
293	schorsch	2.22	loadfunc( /* load definition file */
294			char *fname
295			)
296	greg	1.1	{
297			char *ffname;
298
299	greg	2.18	if ((ffname = getpath(fname, getrlibpath(), R_OK)) == NULL) {
300	greg	1.1	sprintf(errmsg, "cannot find function file \"%s\"", fname);
301	greg	2.31	error(SYSTEM, errmsg);
302	greg	1.1	}
303			fcompile(ffname);
304			}
305
306
307	greg	2.2	static double
308	greg	2.20	l_arg(char nm) / return nth real argument */
309	greg	1.1	{
310	greg	2.25	int n;
311	greg	1.1
312	greg	2.7	if (fobj == NULL)
313	greg	2.31	error(INTERNAL, "arg(n) called without a modifier context");
314	greg	2.7
315	greg	1.1	n = argument(1) + .5; /* round to integer */
316
317			if (n < 1)
318			return(fobj->oargs.nfargs);
319
320			if (n > fobj->oargs.nfargs) {
321			sprintf(errmsg, "missing real argument %d", n);
322			objerror(fobj, USER, errmsg);
323			}
324			return(fobj->oargs.farg[n-1]);
325	greg	1.19	}
326
327
328	greg	2.2	static double
329	greg	2.20	l_erf(char nm) / error function */
330	greg	1.19	{
331			return(erf(argument(1)));
332			}
333
334
335	greg	2.2	static double
336	greg	2.20	l_erfc(char nm) / cumulative error function */
337	greg	1.19	{
338			return(erfc(argument(1)));
339	greg	1.1	}
340
341
342	greg	2.25	double
343	schorsch	2.22	chanvalue( /* return channel n to calcomp */
344	greg	2.25	int n
345	schorsch	2.22	)
346	greg	1.1	{
347	greg	2.7	if (fray == NULL)
348			syntax("ray parameter used in constant expression");
349	greg	1.1
350	greg	1.10	if (--n < 0)
351			goto badchan;
352	greg	1.1
353	greg	2.17	if (n <= 2) /* ray direction */
354	greg	1.1
355	greg	1.12	return( ( fray->rdir[0]*funcxf.xfm[0][n] +
356			fray->rdir[1]*funcxf.xfm[1][n] +
357			fray->rdir[2]*funcxf.xfm[2][n] )
358			/ funcxf.sca );
359	greg	1.1
360	greg	2.17	if (n <= 5) /* surface normal */
361	greg	1.8
362	greg	1.12	return( ( fray->ron[0]*funcxf.xfm[0][n-3] +
363			fray->ron[1]*funcxf.xfm[1][n-3] +
364			fray->ron[2]*funcxf.xfm[2][n-3] )
365			/ funcxf.sca );
366	greg	1.8
367	greg	2.28	if (n <= 8) { /* intersection point */
368			if (fray->rot >= FHUGE)
369			return(0.0); /* XXX should be runtime error? */
370	greg	1.8
371	greg	1.12	return( fray->rop[0]*funcxf.xfm[0][n-6] +
372			fray->rop[1]*funcxf.xfm[1][n-6] +
373			fray->rop[2]*funcxf.xfm[2][n-6] +
374			funcxf.xfm[3][n-6] );
375	greg	2.28	}
376	greg	1.8
377	greg	2.13	if (n == 9) /* total distance */
378			return(raydist(fray,PRIMARY) * funcxf.sca);
379	greg	1.10
380	greg	1.18	if (n == 10) /* dot product (range [-1,1]) */
381			return( fray->rod <= -1.0 ? -1.0 :
382			fray->rod >= 1.0 ? 1.0 :
383			fray->rod );
384	greg	1.10
385	greg	1.8	if (n == 11) /* scale */
386	greg	1.12	return(funcxf.sca);
387	greg	1.8
388	greg	2.17	if (n <= 14) /* origin */
389	greg	1.12	return(funcxf.xfm[3][n-12]);
390	greg	1.8
391	greg	2.17	if (n <= 17) /* i unit vector */
392	greg	1.12	return(funcxf.xfm[0][n-15] / funcxf.sca);
393	greg	1.8
394	greg	2.17	if (n <= 20) /* j unit vector */
395			return(funcxf.xfm[1][n-18] / funcxf.sca);
396	greg	1.8
397	greg	2.17	if (n <= 23) /* k unit vector */
398	greg	1.12	return(funcxf.xfm[2][n-21] / funcxf.sca);
399	greg	2.6
400	greg	2.17	if (n == 24) /* single ray (shadow) distance */
401	greg	2.13	return((fray->rot+raydist(fray->parent,SHADOW)) * funcxf.sca);
402	greg	2.16
403	greg	2.17	if (n <= 26) /* local (u,v) coordinates */
404			return(fray->uv[n-25]);
405	greg	1.10	badchan:
406			error(USER, "illegal channel number");
407	greg	2.16	return(0.0);
408	greg	1.1	}