cv/mgflib/parser.c

/* Copyright (c) 1994 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 * Parse an MGF file, converting or discarding unsupported entities
 */

#include <stdio.h>
#include <math.h>
#include <ctype.h>
#include <string.h>
#include "parser.h"
#include "lookup.h"
#include "messages.h"

/*
 * Global definitions of variables declared in parser.h
 */
                        /* entity names */

char    mg_ename[MG_NENTITIES][MG_MAXELEN] = MG_NAMELIST;

                        /* Handler routines for each entity */

int     (*mg_ehand[MG_NENTITIES])();

                        /* error messages */

char    *mg_err[MG_NERRS] = MG_ERRLIST;

MG_FCTXT        *mg_file;       /* current file context pointer */

int     mg_nqcdivs = MG_NQCD;   /* number of divisions per quarter circle */

/*
 * The idea with this parser is to compensate for any missing entries in
 * mg_ehand with alternate handlers that express these entities in terms
 * of others that the calling program can handle.
 * 
 * In some cases, no alternate handler is possible because the entity
 * has no approximate equivalent.  These entities are simply discarded.
 *
 * Certain entities are dependent on others, and mg_init() will fail
 * if the supported entities are not consistent.
 *
 * Some alternate entity handlers require that earlier entities be
 * noted in some fashion, and we therefore keep another array of
 * parallel support handlers to assist in this effort.
 */

/* temporary settings for testing */
#define e_ies e_any_toss
                                /* alternate handler routines */

static int      e_any_toss(),           /* discard unneeded entity */
                e_ies(),                /* IES luminaire file */
                e_include(),            /* include file */
                e_sph(),                /* sphere */
                e_cmix(),               /* color mixtures */
                e_cspec(),              /* color spectra */
                e_cyl(),                /* cylinder */
                e_cone(),               /* cone */
                e_prism(),              /* prism */
                e_ring(),               /* ring */
                e_torus();              /* torus */

                                /* alternate handler support functions */

static int      (*e_supp[MG_NENTITIES])();

static char     FLTFMT[] = "%.12g";

static int      warpconends;            /* hack for generating good normals */


void
mg_init()                       /* initialize alternate entity handlers */
{
        unsigned long   ineed = 0, uneed = 0;
        register int    i;
                                        /* pick up slack */
        if (mg_ehand[MG_E_IES] == NULL)
                mg_ehand[MG_E_IES] = e_ies;
        if (mg_ehand[MG_E_INCLUDE] == NULL)
                mg_ehand[MG_E_INCLUDE] = e_include;
        if (mg_ehand[MG_E_SPH] == NULL) {
                mg_ehand[MG_E_SPH] = e_sph;
                ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
        } else
                uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
        if (mg_ehand[MG_E_CYL] == NULL) {
                mg_ehand[MG_E_CYL] = e_cyl;
                ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
        } else
                uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
        if (mg_ehand[MG_E_CONE] == NULL) {
                mg_ehand[MG_E_CONE] = e_cone;
                ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
        } else
                uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
        if (mg_ehand[MG_E_RING] == NULL) {
                mg_ehand[MG_E_RING] = e_ring;
                ineed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX;
        } else
                uneed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX|1<<MG_E_XF;
        if (mg_ehand[MG_E_PRISM] == NULL) {
                mg_ehand[MG_E_PRISM] = e_prism;
                ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
        } else
                uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
        if (mg_ehand[MG_E_TORUS] == NULL) {
                mg_ehand[MG_E_TORUS] = e_torus;
                ineed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX;
        } else
                uneed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX|1<<MG_E_XF;
        if (mg_ehand[MG_E_COLOR] != NULL) {
                if (mg_ehand[MG_E_CMIX] == NULL) {
                        mg_ehand[MG_E_CMIX] = e_cmix;
                        ineed |= 1<<MG_E_COLOR|1<<MG_E_CXY|1<<MG_E_CSPEC|1<<MG_E_CMIX;
                }
                if (mg_ehand[MG_E_CSPEC] == NULL) {
                        mg_ehand[MG_E_CSPEC] = e_cspec;
                        ineed |= 1<<MG_E_COLOR|1<<MG_E_CXY|1<<MG_E_CSPEC|1<<MG_E_CMIX;
                }
        }
                                        /* check for consistency */
        if (mg_ehand[MG_E_FACE] != NULL)
                uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
        if (mg_ehand[MG_E_CXY] != NULL || mg_ehand[MG_E_CSPEC] != NULL ||
                        mg_ehand[MG_E_CMIX] != NULL)
                uneed |= 1<<MG_E_COLOR;
        if (mg_ehand[MG_E_RD] != NULL || mg_ehand[MG_E_TD] != NULL ||
                        mg_ehand[MG_E_ED] != NULL || 
                        mg_ehand[MG_E_RS] != NULL ||
                        mg_ehand[MG_E_TS] != NULL ||
                        mg_ehand[MG_E_SIDES] != NULL)
                uneed |= 1<<MG_E_MATERIAL;
        for (i = 0; i < MG_NENTITIES; i++)
                if (uneed & 1<<i && mg_ehand[i] == NULL) {
                        fprintf(stderr, "Missing support for \"%s\" entity\n",
                                        mg_ename[i]);
                        exit(1);
                }
                                        /* add support as needed */
        if (ineed & 1<<MG_E_VERTEX && mg_ehand[MG_E_VERTEX] != c_hvertex)
                e_supp[MG_E_VERTEX] = c_hvertex;
        if (ineed & 1<<MG_E_POINT && mg_ehand[MG_E_POINT] != c_hvertex)
                e_supp[MG_E_POINT] = c_hvertex;
        if (ineed & 1<<MG_E_NORMAL && mg_ehand[MG_E_NORMAL] != c_hvertex)
                e_supp[MG_E_NORMAL] = c_hvertex;
        if (ineed & 1<<MG_E_COLOR && mg_ehand[MG_E_COLOR] != c_hcolor)
                e_supp[MG_E_COLOR] = c_hcolor;
        if (ineed & 1<<MG_E_CXY && mg_ehand[MG_E_CXY] != c_hcolor)
                e_supp[MG_E_CXY] = c_hcolor;
        if (ineed & 1<<MG_E_CSPEC && mg_ehand[MG_E_CSPEC] != c_hcolor)
                e_supp[MG_E_CSPEC] = c_hcolor;
        if (ineed & 1<<MG_E_CMIX && mg_ehand[MG_E_CMIX] != c_hcolor)
                e_supp[MG_E_CMIX] = c_hcolor;
                                        /* discard remaining entities */
        for (i = 0; i < MG_NENTITIES; i++)
                if (mg_ehand[i] == NULL)
                        mg_ehand[i] = e_any_toss;
}


int
mg_entity(name)                 /* get entity number from its name */
char    *name;
{
        static LUTAB    ent_tab = LU_SINIT(NULL,NULL);  /* lookup table */
        register char   *cp;

        if (!ent_tab.tsiz) {            /* initialize hash table */
                if (!lu_init(&ent_tab, MG_NENTITIES))
                        return(-1);             /* what to do? */
                for (cp = mg_ename[MG_NENTITIES-1]; cp >= mg_ename[0];
                                cp -= sizeof(mg_ename[0]))
                        lu_find(&ent_tab, cp)->key = cp;
        }
        cp = lu_find(&ent_tab, name)->key;
        if (cp == NULL)
                return(-1);
        return((cp - mg_ename[0])/sizeof(mg_ename[0]));
}


int
mg_handle(en, ac, av)           /* pass entity to appropriate handler */
register int    en;
int     ac;
char    **av;
{
        int     rv;

        if (en < 0 && (en = mg_entity(av[0])) < 0)
                return(MG_EUNK);
        if (e_supp[en] != NULL) {
                if ((rv = (*e_supp[en])(ac, av)) != MG_OK)
                        return(rv);
        }
        return((*mg_ehand[en])(ac, av));
}


int
mg_open(ctx, fn)                        /* open new input file */
register MG_FCTXT       *ctx;
char    *fn;
{
        static int      nfids;
        int     olen;
        register char   *cp;

        ctx->fid = ++nfids;
        ctx->lineno = 0;
        if (fn == NULL) {
                strcpy(ctx->fname, "<stdin>");
                ctx->fp = stdin;
                ctx->prev = mg_file;
                mg_file = ctx;
                return(MG_OK);
        }
                                        /* get name relative to this context */
        if (mg_file != NULL &&
                        (cp = strrchr(mg_file->fname, '/')) != NULL)
                olen = cp - mg_file->fname + 1;
        else
                olen = 0;
        if (olen)
                strcpy(ctx->fname, mg_file->fname);
        strcpy(ctx->fname+olen, fn);
        ctx->fp = fopen(ctx->fname, "r");
        if (ctx->fp == NULL)
                return(MG_ENOFILE);
        ctx->prev = mg_file;            /* establish new context */
        mg_file = ctx;
        return(MG_OK);
}


void
mg_close()                      /* close input file */
{
        register MG_FCTXT       *ctx = mg_file;

        mg_file = ctx->prev;            /* restore enclosing context */
        if (ctx->fp == stdin)
                return;                 /* don't close standard input */
        fclose(ctx->fp);
}


void
mg_fgetpos(pos)                 /* get current position in input file */
register MG_FPOS        *pos;
{
        extern long     ftell();

        pos->fid = mg_file->fid;
        pos->lineno = mg_file->lineno;
        pos->offset = ftell(mg_file->fp);
}


int
mg_fgoto(pos)                   /* reposition input file pointer */
register MG_FPOS        *pos;
{
        if (pos->fid != mg_file->fid)
                return(MG_ESEEK);
        if (pos->lineno == mg_file->lineno)
                return(MG_OK);
        if (mg_file->fp == stdin)
                return(MG_ESEEK);       /* cannot seek on standard input */
        if (fseek(mg_file->fp, pos->offset, 0) == EOF)
                return(MG_ESEEK);
        mg_file->lineno = pos->lineno;
        return(MG_OK);
}


int
mg_read()                       /* read next line from file */
{
        register int    len = 0;

        do {
                if (fgets(mg_file->inpline+len,
                                MG_MAXLINE-len, mg_file->fp) == NULL)
                        return(len);
                mg_file->lineno++;
                len += strlen(mg_file->inpline+len);
                if (len > 1 && mg_file->inpline[len-2] == '\\')
                        mg_file->inpline[--len-1] = ' ';
        } while (mg_file->inpline[len]);

        return(len);
}


int
mg_parse()                      /* parse current input line */
{
        char    abuf[MG_MAXLINE];
        char    *argv[MG_MAXARGC];
        int     en;
        register char   *cp, **ap;

        strcpy(cp=abuf, mg_file->inpline);
        ap = argv;                      /* break into words */
        for ( ; ; ) {
                while (isspace(*cp))
                        *cp++ = '\0';
                if (!*cp)
                        break;
                if (ap - argv >= MG_MAXARGC-1)
                        return(MG_EARGC);
                *ap++ = cp;
                while (*++cp && !isspace(*cp))
                        ;
        }
        if (ap == argv)
                return(MG_OK);          /* no words in line */
        *ap = NULL;
                                        /* else handle it */
        return(mg_handle(-1, ap-argv, argv));
}


int
mg_load(fn)                     /* load an MGF file */
char    *fn;
{
        MG_FCTXT        cntxt;
        int     rval;

        if ((rval = mg_open(&cntxt, fn)) != MG_OK) {
                fprintf(stderr, "%s: %s\n", fn, mg_err[rval]);
                return(rval);
        }
        while (mg_read())               /* parse each line */
                if ((rval = mg_parse()) != MG_OK) {
                        fprintf(stderr, "%s: %d: %s:\n%s", cntxt.fname,
                                        cntxt.lineno, mg_err[rval],
                                        cntxt.inpline);
                        break;
                }
        mg_close();
        return(rval);
}


void
mg_clear()                      /* clear parser history */
{
        c_clearall();                   /* clear context tables */
        mg_file = NULL;                 /* reset our context */
}


/****************************************************************************
 *      The following routines handle unsupported entities
 */


static int
e_any_toss(ac, av)              /* discard an unwanted entity */
int     ac;
char    **av;
{
        return(MG_OK);
}


static int
e_include(ac, av)               /* include file */
int     ac;
char    **av;
{
        char    *xfarg[MG_MAXARGC];
        MG_FCTXT        ictx;
        int     rv;

        if (ac < 2)
                return(MG_EARGC);
        if ((rv = mg_open(&ictx, av[1])) != MG_OK)
                return(rv);
        if (ac > 2) {
                register int    i;

                xfarg[0] = mg_ename[MG_E_XF];
                for (i = 1; i < ac-1; i++)
                        xfarg[i] = av[i+1];
                xfarg[ac-1] = NULL;
                if ((rv = mg_handle(MG_E_XF, ac-1, xfarg)) != MG_OK)
                        return(rv);
        }
        while (!feof(mg_file->fp)) {
                while (mg_read())
                        if ((rv = mg_parse()) != MG_OK) {
                                fprintf(stderr, "%s: %d: %s:\n%s", ictx.fname,
                                                ictx.lineno, mg_err[rv],
                                                ictx.inpline);
                                mg_close();
                                return(MG_EINCL);
                        }
                if (ac > 2)
                        if ((rv = mg_handle(MG_E_XF, 1, xfarg)) != MG_OK)
                                return(rv);
        }
        mg_close();
        return(MG_OK);
}


static void
make_axes(u, v, w)              /* compute u and v given w (normalized) */
FVECT   u, v, w;
{
        register int    i;

        v[0] = v[1] = v[2] = 0.;
        for (i = 0; i < 3; i++)
                if (w[i] < .6 && w[i] > -.6)
                        break;
        v[i] = 1.;
        fcross(u, v, w);
        normalize(u);
        fcross(v, w, u);
}


static int
e_sph(ac, av)                   /* expand a sphere into cones */
int     ac;
char    **av;
{
        static char     p2x[24], p2y[24], p2z[24], r1[24], r2[24];
        static char     *v1ent[5] = {mg_ename[MG_E_VERTEX],"_sv1","=","_sv2"};
        static char     *v2ent[4] = {mg_ename[MG_E_VERTEX],"_sv2","="};
        static char     *p2ent[5] = {mg_ename[MG_E_POINT],p2x,p2y,p2z};
        static char     *conent[6] = {mg_ename[MG_E_CONE],"_sv1",r1,"_sv2",r2};
        register C_VERTEX       *cv;
        register int    i;
        int     rval;
        double  rad;
        double  theta;

        if (ac != 3)
                return(MG_EARGC);
        if ((cv = c_getvert(av[1])) == NULL)
                return(MG_EUNDEF);
        if (!isflt(av[2]))
                return(MG_ETYPE);
        rad = atof(av[2]);
                                        /* initialize */
        warpconends = 1;
        if ((rval = mg_handle(MG_E_VERTEX, 3, v2ent)) != MG_OK)
                return(rval);
        sprintf(p2x, FLTFMT, cv->p[0]);
        sprintf(p2y, FLTFMT, cv->p[1]);
        sprintf(p2z, FLTFMT, cv->p[2]+rad);
        if ((rval = mg_handle(MG_E_POINT, 4, p2ent)) != MG_OK)
                return(rval);
        r2[0] = '0'; r2[1] = '\0';
        for (i = 1; i <= 2*mg_nqcdivs; i++) {
                theta = i*(PI/2)/mg_nqcdivs;
                if ((rval = mg_handle(MG_E_VERTEX, 4, v1ent)) != MG_OK)
                        return(rval);
                sprintf(p2z, FLTFMT, cv->p[2]+rad*cos(theta));
                if ((rval = mg_handle(MG_E_VERTEX, 2, v2ent)) != MG_OK)
                        return(rval);
                if ((rval = mg_handle(MG_E_POINT, 4, p2ent)) != MG_OK)
                        return(rval);
                strcpy(r1, r2);
                sprintf(r2, FLTFMT, rad*sin(theta));
                if ((rval = mg_handle(MG_E_CONE, 5, conent)) != MG_OK)
                        return(rval);
        }
        warpconends = 0;
        return(MG_OK);
}


static int
e_torus(ac, av)                 /* expand a torus into cones */
int     ac;
char    **av;
{
        static char     p2[3][24], r1[24], r2[24];
        static char     *v1ent[5] = {mg_ename[MG_E_VERTEX],"_tv1","=","_tv2"};
        static char     *v2ent[5] = {mg_ename[MG_E_VERTEX],"_tv2","="};
        static char     *p2ent[5] = {mg_ename[MG_E_POINT],p2[0],p2[1],p2[2]};
        static char     *conent[6] = {mg_ename[MG_E_CONE],"_tv1",r1,"_tv2",r2};
        register C_VERTEX       *cv;
        register int    i, j;
        int     rval;
        int     sgn;
        double  minrad, maxrad, avgrad;
        double  theta;

        if (ac != 4)
                return(MG_EARGC);
        if ((cv = c_getvert(av[1])) == NULL)
                return(MG_EUNDEF);
        if (is0vect(cv->n))
                return(MG_EILL);
        if (!isflt(av[2]) || !isflt(av[3]))
                return(MG_ETYPE);
        minrad = atof(av[2]);
        round0(minrad);
        maxrad = atof(av[3]);
                                        /* check orientation */
        if (minrad > 0.)
                sgn = 1;
        else if (minrad < 0.)
                sgn = -1;
        else if (maxrad > 0.)
                sgn = 1;
        else if (maxrad < 0.)
                sgn = -1;
        else
                return(MG_EILL);
        if (sgn*(maxrad-minrad) <= 0.)
                return(MG_EILL);
                                        /* initialize */
        warpconends = 1;
        v2ent[3] = av[1];
        for (j = 0; j < 3; j++)
                sprintf(p2[j], FLTFMT, cv->p[j] +
                                .5*sgn*(maxrad-minrad)*cv->n[j]);
        if ((rval = mg_handle(MG_E_VERTEX, 4, v2ent)) != MG_OK)
                return(rval);
        if ((rval = mg_handle(MG_E_POINT, 4, p2ent)) != MG_OK)
                return(rval);
        sprintf(r2, FLTFMT, avgrad=.5*(minrad+maxrad));
                                        /* run outer section */
        for (i = 1; i <= 2*mg_nqcdivs; i++) {
                theta = i*(PI/2)/mg_nqcdivs;
                if ((rval = mg_handle(MG_E_VERTEX, 4, v1ent)) != MG_OK)
                        return(rval);
                for (j = 0; j < 3; j++)
                        sprintf(p2[j], FLTFMT, cv->p[j] +
                                .5*sgn*(maxrad-minrad)*cos(theta)*cv->n[j]);
                if ((rval = mg_handle(MG_E_VERTEX, 2, v2ent)) != MG_OK)
                        return(rval);
                if ((rval = mg_handle(MG_E_POINT, 4, p2ent)) != MG_OK)
                        return(rval);
                strcpy(r1, r2);
                sprintf(r2, FLTFMT, avgrad + .5*(maxrad-minrad)*sin(theta));
                if ((rval = mg_handle(MG_E_CONE, 5, conent)) != MG_OK)
                        return(rval);
        }
                                        /* run inner section */
        sprintf(r2, FLTFMT, -.5*(minrad+maxrad));
        for ( ; i <= 4*mg_nqcdivs; i++) {
                theta = i*(PI/2)/mg_nqcdivs;
                for (j = 0; j < 3; j++)
                        sprintf(p2[j], FLTFMT, cv->p[j] +
                                .5*sgn*(maxrad-minrad)*cos(theta)*cv->n[j]);
                if ((rval = mg_handle(MG_E_VERTEX, 4, v1ent)) != MG_OK)
                        return(rval);
                if ((rval = mg_handle(MG_E_VERTEX, 2, v2ent)) != MG_OK)
                        return(rval);
                if ((rval = mg_handle(MG_E_POINT, 4, p2ent)) != MG_OK)
                        return(rval);
                strcpy(r1, r2);
                sprintf(r2, FLTFMT, -avgrad - .5*(maxrad-minrad)*sin(theta));
                if ((rval = mg_handle(MG_E_CONE, 5, conent)) != MG_OK)
                        return(rval);
        }
        warpconends = 0;
        return(MG_OK);
}


static int
e_cyl(ac, av)                   /* replace a cylinder with equivalent cone */
int     ac;
char    **av;
{
        static char     *avnew[6] = {mg_ename[MG_E_CONE]};

        if (ac != 4)
                return(MG_EARGC);
        avnew[1] = av[1];
        avnew[2] = av[2];
        avnew[3] = av[3];
        avnew[4] = av[2];
        return(mg_handle(MG_E_CONE, 5, avnew));
}


static int
e_ring(ac, av)                  /* turn a ring into polygons */
int     ac;
char    **av;
{
        static char     p3[3][24], p4[3][24];
        static char     *nzent[5] = {mg_ename[MG_E_NORMAL],"0","0","0"};
        static char     *v1ent[5] = {mg_ename[MG_E_VERTEX],"_rv1","="};
        static char     *v2ent[5] = {mg_ename[MG_E_VERTEX],"_rv2","=","_rv3"};
        static char     *v3ent[4] = {mg_ename[MG_E_VERTEX],"_rv3","="};
        static char     *p3ent[5] = {mg_ename[MG_E_POINT],p3[0],p3[1],p3[2]};
        static char     *v4ent[4] = {mg_ename[MG_E_VERTEX],"_rv4","="};
        static char     *p4ent[5] = {mg_ename[MG_E_POINT],p4[0],p4[1],p4[2]};
        static char     *fent[6] = {mg_ename[MG_E_FACE],"_rv1","_rv2","_rv3","_rv4"};
        register C_VERTEX       *cv;
        register int    i, j;
        FVECT   u, v;
        double  minrad, maxrad;
        int     rv;
        double  theta, d;

        if (ac != 4)
                return(MG_EARGC);
        if ((cv = c_getvert(av[1])) == NULL)
                return(MG_EUNDEF);
        if (is0vect(cv->n))
                return(MG_EILL);
        if (!isflt(av[2]) || !isflt(av[3]))
                return(MG_ETYPE);
        minrad = atof(av[2]);
        round0(minrad);
        maxrad = atof(av[3]);
        if (minrad < 0. || maxrad <= minrad)
                return(MG_EILL);
                                        /* initialize */
        make_axes(u, v, cv->n);
        for (j = 0; j < 3; j++)
                sprintf(p3[j], FLTFMT, cv->p[j] + maxrad*u[j]);
        if ((rv = mg_handle(MG_E_VERTEX, 3, v3ent)) != MG_OK)
                return(rv);
        if ((rv = mg_handle(MG_E_POINT, 4, p3ent)) != MG_OK)
                return(rv);
        if (minrad == 0.) {             /* closed */
                v1ent[3] = av[1];
                if ((rv = mg_handle(MG_E_VERTEX, 4, v1ent)) != MG_OK)
                        return(rv);
                if ((rv = mg_handle(MG_E_NORMAL, 4, nzent)) != MG_OK)
                        return(rv);
                for (i = 1; i <= 4*mg_nqcdivs; i++) {
                        theta = i*(PI/2)/mg_nqcdivs;
                        if ((rv = mg_handle(MG_E_VERTEX, 4, v2ent)) != MG_OK)
                                return(rv);
                        for (j = 0; j < 3; j++)
                                sprintf(p3[j], FLTFMT, cv->p[j] +
                                                maxrad*u[j]*cos(theta) +
                                                maxrad*v[j]*sin(theta));
                        if ((rv = mg_handle(MG_E_VERTEX, 2, v3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_POINT, 4, p3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_FACE, 4, fent)) != MG_OK)
                                return(rv);
                }
        } else {                        /* open */
                if ((rv = mg_handle(MG_E_VERTEX, 3, v4ent)) != MG_OK)
                        return(rv);
                for (j = 0; j < 3; j++)
                        sprintf(p4[j], FLTFMT, cv->p[j] + minrad*u[j]);
                if ((rv = mg_handle(MG_E_POINT, 4, p4ent)) != MG_OK)
                        return(rv);
                v1ent[3] = "_rv4";
                for (i = 1; i <= 4*mg_nqcdivs; i++) {
                        theta = i*(PI/2)/mg_nqcdivs;
                        if ((rv = mg_handle(MG_E_VERTEX, 4, v1ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_VERTEX, 4, v2ent)) != MG_OK)
                                return(rv);
                        for (j = 0; j < 3; j++) {
                                d = u[j]*cos(theta) + v[j]*sin(theta);
                                sprintf(p3[j], FLTFMT, cv->p[j] + maxrad*d);
                                sprintf(p4[j], FLTFMT, cv->p[j] + minrad*d);
                        }
                        if ((rv = mg_handle(MG_E_VERTEX, 2, v3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_POINT, 4, p3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_VERTEX, 2, v4ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_POINT, 4, p4ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_FACE, 5, fent)) != MG_OK)
                                return(rv);
                }
        }
        return(MG_OK);
}


static int
e_cone(ac, av)                  /* turn a cone into polygons */
int     ac;
char    **av;
{
        static char     p3[3][24], p4[3][24], n3[3][24], n4[3][24];
        static char     *v1ent[5] = {mg_ename[MG_E_VERTEX],"_cv1","="};
        static char     *v2ent[5] = {mg_ename[MG_E_VERTEX],"_cv2","=","_cv3"};
        static char     *v3ent[4] = {mg_ename[MG_E_VERTEX],"_cv3","="};
        static char     *p3ent[5] = {mg_ename[MG_E_POINT],p3[0],p3[1],p3[2]};
        static char     *n3ent[5] = {mg_ename[MG_E_NORMAL],n3[0],n3[1],n3[2]};
        static char     *v4ent[4] = {mg_ename[MG_E_VERTEX],"_cv4","="};
        static char     *p4ent[5] = {mg_ename[MG_E_POINT],p4[0],p4[1],p4[2]};
        static char     *n4ent[5] = {mg_ename[MG_E_NORMAL],n4[0],n4[1],n4[2]};
        static char     *fent[6] = {mg_ename[MG_E_FACE],"_cv1","_cv2","_cv3","_cv4"};
        register C_VERTEX       *cv1, *cv2;
        register int    i, j;
        FVECT   u, v, w;
        double  rad1, rad2;
        int     sgn;
        double  n1off, n2off;
        double  d;
        int     rv;
        double  theta;

        if (ac != 5)
                return(MG_EARGC);
        if ((cv1 = c_getvert(av[1])) == NULL ||
                        (cv2 = c_getvert(av[3])) == NULL)
                return(MG_EUNDEF);
        if (!isflt(av[2]) || !isflt(av[4]))
                return(MG_ETYPE);
        rad1 = atof(av[2]);
        round0(rad1);
        rad2 = atof(av[4]);
        round0(rad2);
        if (rad1 == 0.) {
                if (rad2 == 0.)
                        return(MG_EILL);
        } else if (rad2 != 0.) {
                if (rad1 < 0. ^ rad2 < 0.)
                        return(MG_EILL);
        } else {                        /* swap */
                C_VERTEX        *cv;

                cv = cv1;
                cv1 = cv2;
                cv2 = cv;
                d = rad1;
                rad1 = rad2;
                rad2 = d;
        }
        sgn = rad2 < 0. ? -1 : 1;
                                        /* initialize */
        for (j = 0; j < 3; j++)
                w[j] = cv1->p[j] - cv2->p[j];
        if ((d = normalize(w)) == 0.)
                return(MG_EILL);
        n1off = n2off = (rad2 - rad1)/d;
        if (warpconends) {              /* hack for e_sph and e_torus */
                d = atan(n2off) - (PI/4)/mg_nqcdivs;
                if (d <= -PI/2+FTINY)
                        n2off = -FHUGE;
                else
                        n2off = tan(d);
        }
        make_axes(u, v, w);
        for (j = 0; j < 3; j++) {
                sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*u[j]);
                if (n2off <= -FHUGE)
                        sprintf(n3[j], FLTFMT, -w[j]);
                else
                        sprintf(n3[j], FLTFMT, u[j] + w[j]*n2off);
        }
        if ((rv = mg_handle(MG_E_VERTEX, 3, v3ent)) != MG_OK)
                return(rv);
        if ((rv = mg_handle(MG_E_POINT, 4, p3ent)) != MG_OK)
                return(rv);
        if ((rv = mg_handle(MG_E_NORMAL, 4, n3ent)) != MG_OK)
                return(rv);
        if (rad1 == 0.) {               /* triangles */
                v1ent[3] = av[1];
                if ((rv = mg_handle(MG_E_VERTEX, 4, v1ent)) != MG_OK)
                        return(rv);
                for (j = 0; j < 3; j++)
                        sprintf(n4[j], FLTFMT, w[j]);
                if ((rv = mg_handle(MG_E_NORMAL, 4, n4ent)) != MG_OK)
                        return(rv);
                for (i = 1; i <= 4*mg_nqcdivs; i++) {
                        theta = sgn*i*(PI/2)/mg_nqcdivs;
                        if ((rv = mg_handle(MG_E_VERTEX, 4, v2ent)) != MG_OK)
                                return(rv);
                        for (j = 0; j < 3; j++) {
                                d = u[j]*cos(theta) + v[j]*sin(theta);
                                sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*d);
                                if (n2off > -FHUGE)
                                        sprintf(n3[j], FLTFMT, d + w[j]*n2off);
                        }
                        if ((rv = mg_handle(MG_E_VERTEX, 2, v3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_POINT, 4, p3ent)) != MG_OK)
                                return(rv);
                        if (n2off > -FHUGE &&
                        (rv = mg_handle(MG_E_NORMAL, 4, n3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_FACE, 4, fent)) != MG_OK)
                                return(rv);
                }
        } else {                        /* quads */
                v1ent[3] = "_cv4";
                if (warpconends) {              /* hack for e_sph and e_torus */
                        d = atan(n1off) + (PI/4)/mg_nqcdivs;
                        if (d >= PI/2-FTINY)
                                n1off = FHUGE;
                        else
                                n1off = tan(atan(n1off)+(PI/4)/mg_nqcdivs);
                }
                for (j = 0; j < 3; j++) {
                        sprintf(p4[j], FLTFMT, cv1->p[j] + rad1*u[j]);
                        if (n1off >= FHUGE)
                                sprintf(n4[j], FLTFMT, w[j]);
                        else
                                sprintf(n4[j], FLTFMT, u[j] + w[j]*n1off);
                }
                if ((rv = mg_handle(MG_E_VERTEX, 3, v4ent)) != MG_OK)
                        return(rv);
                if ((rv = mg_handle(MG_E_POINT, 4, p4ent)) != MG_OK)
                        return(rv);
                if ((rv = mg_handle(MG_E_NORMAL, 4, n4ent)) != MG_OK)
                        return(rv);
                for (i = 1; i <= 4*mg_nqcdivs; i++) {
                        theta = sgn*i*(PI/2)/mg_nqcdivs;
                        if ((rv = mg_handle(MG_E_VERTEX, 4, v1ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_VERTEX, 4, v2ent)) != MG_OK)
                                return(rv);
                        for (j = 0; j < 3; j++) {
                                d = u[j]*cos(theta) + v[j]*sin(theta);
                                sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*d);
                                if (n2off > -FHUGE)
                                        sprintf(n3[j], FLTFMT, d + w[j]*n2off);
                                sprintf(p4[j], FLTFMT, cv1->p[j] + rad1*d);
                                if (n1off < FHUGE)
                                        sprintf(n4[j], FLTFMT, d + w[j]*n1off);
                        }
                        if ((rv = mg_handle(MG_E_VERTEX, 2, v3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_POINT, 4, p3ent)) != MG_OK)
                                return(rv);
                        if (n2off > -FHUGE &&
                        (rv = mg_handle(MG_E_NORMAL, 4, n3ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_VERTEX, 2, v4ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_POINT, 4, p4ent)) != MG_OK)
                                return(rv);
                        if (n1off < FHUGE &&
                        (rv = mg_handle(MG_E_NORMAL, 4, n4ent)) != MG_OK)
                                return(rv);
                        if ((rv = mg_handle(MG_E_FACE, 5, fent)) != MG_OK)
                                return(rv);
                }
        }
        return(MG_OK);
}


static int
e_prism(ac, av)                 /* turn a prism into polygons */
int     ac;
char    **av;
{
        static char     p[3][24];
        static char     *vent[4] = {mg_ename[MG_E_VERTEX],NULL,"="};
        static char     *pent[5] = {mg_ename[MG_E_POINT],p[0],p[1],p[2]};
        char    *newav[MG_MAXARGC], nvn[MG_MAXARGC-1][8];
        double  length;
        FVECT   v1, v2, v3, norm;
        register C_VERTEX       *cv;
        C_VERTEX        *cv0;
        int     rv;
        register int    i, j;

        if (ac < 5)
                return(MG_EARGC);
        if (!isflt(av[ac-1]))
                return(MG_ETYPE);
        length = atof(av[ac-1]);
        if (length <= FTINY && length >= -FTINY)
                return(MG_EILL);
                                        /* do bottom face */
        newav[0] = mg_ename[MG_E_FACE];
        for (i = 1; i < ac-1; i++)
                newav[i] = av[i];
        newav[i] = NULL;
        if ((rv = mg_handle(MG_E_FACE, i, newav)) != MG_OK)
                return(rv);
                                        /* compute face normal */
        if ((cv0 = c_getvert(av[1])) == NULL)
                return(MG_EUNDEF);
        norm[0] = norm[1] = norm[2] = 0.;
        v1[0] = v1[1] = v1[2] = 0.;
        for (i = 2; i < ac-1; i++) {
                if ((cv = c_getvert(av[i])) == NULL)
                        return(MG_EUNDEF);
                v2[0] = cv->p[0] - cv0->p[0];
                v2[1] = cv->p[1] - cv0->p[1];
                v2[2] = cv->p[2] - cv0->p[2];
                fcross(v3, v1, v2);
                norm[0] += v3[0];
                norm[1] += v3[1];
                norm[2] += v3[2];
                VCOPY(v1, v2);
        }
        if (normalize(norm) == 0.)
                return(MG_EILL);
                                        /* create moved vertices */
        for (i = 1; i < ac-1; i++) {
                sprintf(nvn[i-1], "_pv%d", i);
                vent[1] = nvn[i-1];
                if ((rv = mg_handle(MG_E_VERTEX, 3, vent)) != MG_OK)
                        return(rv);
                cv = c_getvert(av[i]);          /* checked above */
                for (j = 0; j < 3; j++)
                        sprintf(p[j], FLTFMT, cv->p[j] - length*norm[j]);
                if ((rv = mg_handle(MG_E_POINT, 4, pent)) != MG_OK)
                        return(rv);
                newav[ac-1-i] = nvn[i-1];       /* reverse */
        }
                                                /* do top face */
        if ((rv = mg_handle(MG_E_FACE, ac-1, newav)) != MG_OK)
                return(rv);
                                                /* do the side faces */
        newav[5] = NULL;
        newav[3] = av[ac-2];
        newav[4] = nvn[ac-3];
        for (i = 1; i < ac-1; i++) {
                newav[1] = nvn[i-1];
                newav[2] = av[i];
                if ((rv = mg_handle(MG_E_FACE, 5, newav)) != MG_OK)
                        return(rv);
                newav[3] = newav[2];
                newav[4] = newav[1];
        }
        return(MG_OK);
}


static int
e_cspec(ac, av)                 /* handle spectral color */
int     ac;
char    **av;
{
        static char     xbuf[24], ybuf[24];
        static char     *ccom[4] = {mg_ename[MG_E_CXY], xbuf, ybuf};
        int     rv;

        c_ccvt(c_ccolor, C_CSXY);
                                /* if it's really their handler, use it */
        if (mg_ehand[MG_E_CXY] != c_hcolor) {
                sprintf(xbuf, "%.4f", c_ccolor->cx);
                sprintf(ybuf, "%.4f", c_ccolor->cy);
                if ((rv = mg_handle(MG_E_CXY, 3, ccom)) != MG_OK)
                        return(rv);
        }
        return(MG_OK);
}


static int
e_cmix(ac, av)                  /* handle mixing of colors */
int     ac;
char    **av;
{
        char    wl[2][6], vbuf[C_CNSS][24];
        char    *newav[C_CNSS+4];
        int     rv;
        register int    i;
        /*
         * Contorted logic works as follows:
         *      1. the colors are already mixed in c_hcolor() support function
         *      2. if we would handle a spectral result, make sure it's not
         *      3. if c_hcolor() would handle a spectral result, don't bother
         *      4. otherwise, make cspec entity and pass it to their handler
         *      5. if we have only xy results, handle it as c_spec() would
         */
        if (mg_ehand[MG_E_CSPEC] == e_cspec)
                c_ccvt(c_ccolor, C_CSXY);
        else if (c_ccolor->flags & C_CDSPEC) {
                if (mg_ehand[MG_E_CSPEC] != c_hcolor) {
                        sprintf(wl[0], "%d", C_CMINWL);
                        sprintf(wl[1], "%d", C_CMAXWL);
                        newav[0] = mg_ename[MG_E_CSPEC];
                        newav[1] = wl[0];
                        newav[2] = wl[1];
                        for (i = 0; i < C_CNSS; i++) {
                                sprintf(vbuf[i], "%.6f",
                                                (double)c_ccolor->ssamp[i] /
                                                c_ccolor->ssum);
                                newav[i+3] = vbuf[i];
                        }
                        newav[C_CNSS+3] = NULL;
                        if ((rv = mg_handle(MG_E_CSPEC, C_CNSS+3, newav)) != MG_OK)
                                return(rv);
                }
                return(MG_OK);
        }
        if (mg_ehand[MG_E_CXY] != c_hcolor) {
                sprintf(vbuf[0], "%.4f", c_ccolor->cx);
                sprintf(vbuf[1], "%.4f", c_ccolor->cy);
                newav[0] = mg_ename[MG_E_CXY];
                newav[1] = vbuf[0];
                newav[2] = vbuf[1];
                newav[3] = NULL;
                if ((rv = mg_handle(MG_E_CXY, 3, newav)) != MG_OK)
                        return(rv);
        }
        return(MG_OK);
}
Revision:	1.11
Committed:	Fri Jul 1 18:06:58 1994 UTC (29 years, 10 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.10:	+2 -1 lines
Log Message:	added "sides" entity for one- vs. two-sided surfaces