src/cv/mgf2rad.c

#ifndef lint
static const char       RCSid[] = "$Id: mgf2rad.c,v 2.35 2024/01/17 00:43:45 greg Exp $";
#endif
/*
 * Convert MGF (Materials and Geometry Format) to Radiance
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

#include "platform.h"
#include "mgf_parser.h"
#include "color.h"
#include "tmesh.h"
#include "lookup.h"

#define putv(v)         printf("%18.12g %18.12g %18.12g\n",(v)[0],(v)[1],(v)[2])

#define invert          (xf_context != NULL && xf_context->rev)

#define SGEN_DEF        "spec*"
#define SGEN_RS         "rs_spec*"
#define SGEN_TD         "td_spec*"
#define SGEN_TS         "ts_spec*"

char    void_str[] = "void";            /* global VOIDID */
char    sgen_str[16] = SGEN_DEF;        /* generic specular */

double  glowdist = FHUGE;               /* glow test distance */

double  emult = 1.;                     /* emitter multiplier */

FILE    *matfp;                         /* material output file */

int     dospectra = 0;                  /* output spectral colors? */


extern int r_comment(int ac, char **av);
extern int r_color(int ac, char **av);
extern int r_cone(int ac, char **av);
extern int r_cyl(int ac, char **av);
extern int r_sph(int ac, char **av);
extern int r_ring(int ac, char **av);
extern int r_face(int ac, char **av);
extern int r_ies(int ac, char **av);
extern void putsided(char *mname);
extern char * material(void);
extern char * object(void);
extern char * addarg(char *op, char *arg);
extern void do_tri(char *mat, C_VERTEX *cv1, C_VERTEX *cv2, C_VERTEX *cv3, int iv);
extern void cvtcolor(COLOR radrgb, C_COLOR *ciec, double intensity);
extern int color_clash(int e1, int e2);
extern int isgrey(COLOR rgb);
extern void putrgbpat(char *pnm, COLOR rgb);
extern char * specolor(COLOR radrgb, C_COLOR *ciec, double intensity);


int
main(
        int     argc,
        char    *argv[]
)
{
        int     i;

        matfp = stdout;
                                /* print out parser version */
        printf("## Translated from MGF Version %d.%d\n", MG_VMAJOR, MG_VMINOR);
                                /* initialize dispatch table */
        mg_ehand[MG_E_COMMENT] = r_comment;     /* we pass comments */
        mg_ehand[MG_E_COLOR] = c_hcolor;        /* they get color */
        mg_ehand[MG_E_CONE] = r_cone;           /* we do cones */
        mg_ehand[MG_E_CMIX] = c_hcolor;         /* they mix colors */
        mg_ehand[MG_E_CXY] = c_hcolor;          /* they get chromaticities */
        mg_ehand[MG_E_CSPEC] = r_color;         /* we get spectra */
        mg_ehand[MG_E_CCT] = r_color;           /* we get color temp's */
        mg_ehand[MG_E_CYL] = r_cyl;             /* we do cylinders */
        mg_ehand[MG_E_ED] = c_hmaterial;        /* they get emission */
        mg_ehand[MG_E_FACE] = r_face;           /* we do faces */
        mg_ehand[MG_E_IES] = r_ies;             /* we do IES files */
        mg_ehand[MG_E_IR] = c_hmaterial;        /* they get refractive index */
        mg_ehand[MG_E_MATERIAL] = c_hmaterial;  /* they get materials */
        mg_ehand[MG_E_NORMAL] = c_hvertex;      /* they get normals */
        mg_ehand[MG_E_OBJECT] = obj_handler;    /* they track object names */
        mg_ehand[MG_E_POINT] = c_hvertex;       /* they get points */
        mg_ehand[MG_E_RD] = c_hmaterial;        /* they get diffuse refl. */
        mg_ehand[MG_E_RING] = r_ring;           /* we do rings */
        mg_ehand[MG_E_RS] = c_hmaterial;        /* they get specular refl. */
        mg_ehand[MG_E_SIDES] = c_hmaterial;     /* they get # sides */
        mg_ehand[MG_E_SPH] = r_sph;             /* we do spheres */
        mg_ehand[MG_E_TD] = c_hmaterial;        /* they get diffuse trans. */
        mg_ehand[MG_E_TS] = c_hmaterial;        /* they get specular trans. */
        mg_ehand[MG_E_VERTEX] = c_hvertex;      /* they get vertices */
        mg_ehand[MG_E_XF] = xf_handler;         /* they track transforms */
        mg_init();              /* initialize the parser */
                                        /* get our options & print header */
        printf("## %s", argv[0]);
        for (i = 1; i < argc && argv[i][0] == '-'; i++) {
                printf(" %s", argv[i]);
                switch (argv[i][1]) {
                case 'g':                       /* glow distance (meters) */
                        if (argv[i][2] || badarg(argc-i-1, argv+i+1, "f"))
                                goto userr;
                        glowdist = atof(argv[++i]);
                        printf(" %s", argv[i]);
                        break;
                case 'e':                       /* emitter multiplier */
                        if (argv[i][2] || badarg(argc-i-1, argv+i+1, "f"))
                                goto userr;
                        emult = atof(argv[++i]);
                        printf(" %s", argv[i]);
                        break;
                case 'm':                       /* materials file */
                        matfp = fopen(argv[++i], "a");
                        if (matfp == NULL) {
                                fprintf(stderr, "%s: cannot append\n", argv[i]);
                                exit(1);
                        }
                        printf(" %s", argv[i]);
                        break;
                case 's':                       /* spectral color output? */
                        dospectra = !dospectra;
                        break;
                default:
                        goto userr;
                }
        }
        putchar('\n');
        if (i == argc) {                /* convert stdin */
                if (mg_load(NULL) != MG_OK)
                        exit(1);
                if (mg_nunknown)
                        printf("## %s: %u unknown entities\n",
                                        argv[0], mg_nunknown);
        } else                          /* convert each file */
                for ( ; i < argc; i++) {
                        printf("## %s %s ##############################\n",
                                        argv[0], argv[i]);
                        if (mg_load(argv[i]) != MG_OK)
                                exit(1);
                        if (mg_nunknown) {
                                printf("## %s %s: %u unknown entities\n",
                                                argv[0], argv[i], mg_nunknown);
                                mg_nunknown = 0;
                        }
                }
        exit(0);
userr:
        fprintf(stderr, "Usage: %s [-s][-g dist][-e mult][-m matf] [file.mgf] ..\n",
                        argv[0]);
        exit(1);
}


int
r_comment(              /* repeat a comment verbatim */
        int     ac,
        char    **av
)
{
        putchar('#');           /* use Radiance comment character */
        while (--ac) {                  /* pass through verbatim */
                putchar(' ');
                fputs(*++av, stdout);
        }
        putchar('\n');
        return(MG_OK);
}


int
r_color(                /* call color handler & remember name */
        int     ac,
        char    **av
)
{
        int     rval = c_hcolor(ac, av);

        if (rval == MG_OK)
                c_ccolor->client_data = c_ccname;

        return(rval);
}


int
r_cone(                 /* put out a cone */
        int     ac,
        char    **av
)
{
        static int      ncones;
        char    *mat;
        double  r1, r2;
        C_VERTEX        *cv1, *cv2;
        FVECT   p1, p2;
        int     inv;
                                        /* check argument count and type */
        if (ac != 5)
                return(MG_EARGC);
        if (!isflt(av[2]) || !isflt(av[4]))
                return(MG_ETYPE);
                                        /* get the endpoint vertices */
        if ((cv1 = c_getvert(av[1])) == NULL ||
                        (cv2 = c_getvert(av[3])) == NULL)
                return(MG_EUNDEF);
        xf_xfmpoint(p1, cv1->p);        /* transform endpoints */
        xf_xfmpoint(p2, cv2->p);
        r1 = xf_scale(atof(av[2]));     /* scale radii */
        r2 = xf_scale(atof(av[4]));
        inv = r1 < 0.;                  /* check for inverted cone */
        if (r1 == 0.) {                 /* check for illegal radii */
                if (r2 == 0.)
                        return(MG_EILL);
                inv = r2 < 0.;
        } else if (r2 != 0. && inv ^ (r2 < 0.))
                return(MG_EILL);
        if (inv) {
                r1 = -r1;
                r2 = -r2;
        }
        if ((mat = material()) == NULL) /* get material */
                return(MG_EBADMAT);
                                        /* spit the sucker out */
        printf("\n%s %s %sc%d\n", mat, inv ? "cup" : "cone",
                        object(), ++ncones);
        printf("0\n0\n8\n");
        putv(p1);
        putv(p2);
        printf("%18.12g %18.12g\n", r1, r2);
        return(MG_OK);
}


int
r_cyl(                  /* put out a cylinder */
        int     ac,
        char    **av
)
{
        static int      ncyls;
        char    *mat;
        double  rad;
        C_VERTEX        *cv1, *cv2;
        FVECT   p1, p2;
        int     inv;
                                        /* check argument count and type */
        if (ac != 4)
                return(MG_EARGC);
        if (!isflt(av[2]))
                return(MG_ETYPE);
                                        /* get the endpoint vertices */
        if ((cv1 = c_getvert(av[1])) == NULL ||
                        (cv2 = c_getvert(av[3])) == NULL)
                return(MG_EUNDEF);
        xf_xfmpoint(p1, cv1->p);        /* transform endpoints */
        xf_xfmpoint(p2, cv2->p);
        rad = xf_scale(atof(av[2]));    /* scale radius */
        if ((inv = rad < 0.))           /* check for inverted cylinder */
                rad = -rad;
        if ((mat = material()) == NULL) /* get material */
                return(MG_EBADMAT);
                                        /* spit out the primitive */
        printf("\n%s %s %scy%d\n", mat, inv ? "tube" : "cylinder",
                        object(), ++ncyls);
        printf("0\n0\n7\n");
        putv(p1);
        putv(p2);
        printf("%18.12g\n", rad);
        return(MG_OK);
}


int
r_sph(                  /* put out a sphere */
        int     ac,
        char    **av
)
{
        static int      nsphs;
        char    *mat;
        double  rad;
        C_VERTEX        *cv;
        FVECT   cent;
        int     inv;
                                        /* check argument count and type */
        if (ac != 3)
                return(MG_EARGC);
        if (!isflt(av[2]))
                return(MG_ETYPE);
        if ((cv = c_getvert(av[1])) == NULL)    /* get center vertex */
                return(MG_EUNDEF);
        xf_xfmpoint(cent, cv->p);               /* transform center */
        rad = xf_scale(atof(av[2]));            /* scale radius */
        if ((inv = rad < 0.))                   /* check for inversion */
                rad = -rad;
        if ((mat = material()) == NULL)         /* get material */
                return(MG_EBADMAT);
                                                /* spit out primitive */
        printf("\n%s %s %ss%d\n", mat, inv ? "bubble" : "sphere",
                        object(), ++nsphs);
        printf("0\n0\n4 %18.12g %18.12g %18.12g %18.12g\n",
                        cent[0], cent[1], cent[2], rad);
        return(MG_OK);
}


int
r_ring(                 /* put out a ring */
        int     ac,
        char    **av
)
{
        static int      nrings;
        char    *mat;
        double  r1, r2;
        C_VERTEX        *cv;
        FVECT   cent, norm;
                                        /* check argument count and type */
        if (ac != 4)
                return(MG_EARGC);
        if (!isflt(av[2]) || !isflt(av[3]))
                return(MG_ETYPE);
        if ((cv = c_getvert(av[1])) == NULL)    /* get center vertex */
                return(MG_EUNDEF);
        if (is0vect(cv->n))                     /* make sure we have normal */
                return(MG_EILL);
        xf_xfmpoint(cent, cv->p);               /* transform center */
        xf_rotvect(norm, cv->n);                /* rotate normal */
        r1 = xf_scale(atof(av[2]));             /* scale radii */
        r2 = xf_scale(atof(av[3]));
        if ((r1 < 0.) | (r2 <= r1))
                return(MG_EILL);
        if ((mat = material()) == NULL)         /* get material */
                return(MG_EBADMAT);
                                                /* spit out primitive */
        printf("\n%s ring %sr%d\n", mat, object(), ++nrings);
        printf("0\n0\n8\n");
        putv(cent);
        putv(norm);
        printf("%18.12g %18.12g\n", r1, r2);
        return(MG_OK);
}


int
r_face(                 /* convert a face */
        int     ac,
        char    **av
)
{
        static int      nfaces;
        int             myi = invert;
        char    *mat;
        int     i;
        C_VERTEX        *cv;
        FVECT   v;

                                        /* check argument count and type */
        if (ac < 4)
                return(MG_EARGC);
        if ((mat = material()) == NULL) /* get material */
                return(MG_EBADMAT);
        if (ac <= 5) {                          /* check for smoothing */
                C_VERTEX        *cva[5];
                for (i = 1; i < ac; i++) {
                        if ((cva[i-1] = c_getvert(av[i])) == NULL)
                                return(MG_EUNDEF);
                        if (is0vect(cva[i-1]->n))
                                break;
                }
                if (i < ac)
                        i = ISFLAT;
                else
                        i = flat_tri(cva[0]->p, cva[1]->p, cva[2]->p,
                                        cva[0]->n, cva[1]->n, cva[2]->n);
                if (i == DEGEN)
                        return(MG_OK);          /* degenerate (error?) */
                if (i == RVBENT) {
                        myi = !myi;
                        i = ISBENT;
                } else if (i == RVFLAT) {
                        myi = !myi;
                        i = ISFLAT;
                }
                if (i == ISBENT) {              /* smoothed triangles */
                        do_tri(mat, cva[0], cva[1], cva[2], myi);
                        if (ac == 5)
                                do_tri(mat, cva[2], cva[3], cva[0], myi);
                        return(MG_OK);
                }
        }
                                        /* spit out unsmoothed primitive */
        printf("\n%s polygon %sf%d\n", mat, object(), ++nfaces);
        printf("0\n0\n%d\n", 3*(ac-1));
        for (i = 1; i < ac; i++) {      /* get, transform, print each vertex */
                if ((cv = c_getvert(av[myi ? ac-i : i])) == NULL)
                        return(MG_EUNDEF);
                xf_xfmpoint(v, cv->p);
                putv(v);
        }
        return(MG_OK);
}


int
r_ies(                          /* convert an IES luminaire file */
        int     ac,
        char    **av
)
{
        int     xa0 = 2;
        char    combuf[128];
        char    fname[48];
        char    *oname;
        char    *op;
        int     i;
                                        /* check argument count */
        if (ac < 2)
                return(MG_EARGC);
                                        /* construct output file name */
        if ((op = strrchr(av[1], '/')) != NULL)
                op++;
        else
                op = av[1];
        (void)strcpy(fname, op);
        if ((op = strrchr(fname, '.')) == NULL)
                op = fname + strlen(fname);
        (void)strcpy(op, ".rad");
                                        /* see if we need to run ies2rad */
        if (access(fname, 0) == -1) {
                (void)strcpy(combuf, "ies2rad");/* build ies2rad command */
                op = combuf + 7;                /* get -m option (first) */
                if (ac-xa0 >= 2 && !strcmp(av[xa0], "-m")) {
                        if (!isflt(av[xa0+1]))
                                return(MG_ETYPE);
                        op = addarg(addarg(op, "-m"), av[xa0+1]);
                        xa0 += 2;
                }
                *op++ = ' ';                    /* build IES filename */
                i = 0;
                if (mg_file != NULL &&
                                (oname = strrchr(mg_file->fname,'/')) != NULL) {
                        i = oname - mg_file->fname + 1;
                        (void)strcpy(op, mg_file->fname);
                }
                (void)strcpy(op+i, av[1]);
                if (access(op, 0) == -1)        /* check for file existence */
                        return(MG_ENOFILE);
                system(combuf);                 /* run ies2rad */
                if (access(fname, 0) == -1)     /* check success */
                        return(MG_EINCL);
        }
        printf("\n!xform");                     /* put out xform command */
        oname = object();
        if (*oname) {
                printf(" -n ");
                for (op = oname; op[1]; op++)   /* remove trailing separator */
                        putchar(*op);
        }
        for (i = xa0; i < ac; i++)
                printf(" %s", av[i]);
        if (ac > xa0 && xf_argc > 0)
                printf(" -i 1");
        for (i = 0; i < xf_argc; i++)
                printf(" %s", xf_argv[i]);
        printf(" %s\n", fname);
        return(MG_OK);
}


void
do_tri(         /* put out smoothed triangle */
        char    *mat,
        C_VERTEX        *cv1,
        C_VERTEX        *cv2,
        C_VERTEX        *cv3,
        int     iv
)
{
        static int      ntris;
        BARYCCM bvecs;
        RREAL   bcoor[3][3];
        C_VERTEX        *cvt;
        FVECT   v1, v2, v3;
        FVECT   n1, n2, n3;
        int     i;

        if (iv) {                       /* swap vertex order if inverted */
                cvt = cv1;
                cv1 = cv3;
                cv3 = cvt;
        }
        xf_xfmpoint(v1, cv1->p);
        xf_xfmpoint(v2, cv2->p);
        xf_xfmpoint(v3, cv3->p);
                                        /* compute barycentric coords. */
        if (comp_baryc(&bvecs, v1, v2, v3) < 0)
                return;                         /* degenerate triangle! */
        printf("\n%s texfunc T-nor\n", mat);    /* put out texture */
        printf("4 dx dy dz %s\n0\n", TCALNAME);
        xf_rotvect(n1, cv1->n);
        xf_rotvect(n2, cv2->n);
        xf_rotvect(n3, cv3->n);
        for (i = 0; i < 3; i++) {
                bcoor[i][0] = n1[i];
                bcoor[i][1] = n2[i];
                bcoor[i][2] = n3[i];
        }
        fput_baryc(&bvecs, bcoor, 3, stdout);
                                                /* put out triangle */
        printf("\nT-nor polygon %st%d\n", object(), ++ntris);
        printf("0\n0\n9\n");
        putv(v1);
        putv(v2);
        putv(v3);
}


void
putsided(char *mname)           /* print out mixfunc for sided material */
{
        fprintf(matfp, "\nvoid mixfunc %s\n", mname);
        fprintf(matfp, "4 %s void if(Rdot,1,0) .\n0\n0\n", mname);
}


char *
material(void)                  /* get (and print) current material */
{
        char    *mname = "mat";
        C_COLOR *refclr = NULL;
        char    *pname;
        COLOR   radrgb, c2;
        double  d;

        if (c_cmname != NULL)
                mname = c_cmname;
        if (!c_cmaterial->clock)
                return(mname);          /* already current */
                                /* else update output */
        c_cmaterial->clock = 0;
        if (c_cmaterial->ed > .1) {     /* emitter */
                pname = specolor(radrgb, &c_cmaterial->ed_c,
                                emult*c_cmaterial->ed/(PI*WHTEFFICACY));
                if (glowdist < FHUGE) {         /* do a glow */
                        fprintf(matfp, "\n%s glow %s\n0\n0\n", pname, mname);
                        fprintf(matfp, "4 %f %f %f %f\n", colval(radrgb,RED),
                                        colval(radrgb,GRN),
                                        colval(radrgb,BLU), glowdist);
                } else {
                        fprintf(matfp, "\n%s light %s\n0\n0\n", pname, mname);
                        fprintf(matfp, "3 %f %f %f\n", colval(radrgb,RED),
                                        colval(radrgb,GRN),
                                        colval(radrgb,BLU));
                }
                return(mname);
        }
        d = c_cmaterial->rd + c_cmaterial->td +
                        c_cmaterial->rs + c_cmaterial->ts;
        if ((d < 0.) | (d > 1.))
                return(NULL);
                                        /* check for glass/dielectric */
        if (c_cmaterial->nr > 1.1 &&
                        c_cmaterial->ts > .25 && c_cmaterial->rs <= .125 &&
                        c_cmaterial->td <= .01 && c_cmaterial->rd <= .01 &&
                        c_cmaterial->rs_a <= .01 && c_cmaterial->ts_a <= .01) {
                cvtcolor(radrgb, &c_cmaterial->ts_c,
                                c_cmaterial->ts + c_cmaterial->rs);
                if (c_cmaterial->sided) {               /* dielectric */
                        colval(radrgb,RED) = pow(colval(radrgb,RED),
                                                        1./C_1SIDEDTHICK);
                        colval(radrgb,GRN) = pow(colval(radrgb,GRN),
                                                        1./C_1SIDEDTHICK);
                        colval(radrgb,BLU) = pow(colval(radrgb,BLU),
                                                        1./C_1SIDEDTHICK);
                        fprintf(matfp, "\nvoid dielectric %s\n0\n0\n", mname);
                        fprintf(matfp, "5 %g %g %g %f 0\n", colval(radrgb,RED),
                                        colval(radrgb,GRN), colval(radrgb,BLU),
                                        c_cmaterial->nr);
                        return(mname);
                }
                                                        /* glass */
                fprintf(matfp, "\nvoid glass %s\n0\n0\n", mname);
                fprintf(matfp, "4 %f %f %f %f\n", colval(radrgb,RED),
                                colval(radrgb,GRN), colval(radrgb,BLU),
                                c_cmaterial->nr);
                return(mname);
        }
                                        /* check for WGMDfunc */
        if (((c_cmaterial->rs > .02) & (c_cmaterial->ts > .02) &&
                        fabs(c_cmaterial->rs_a - c_cmaterial->ts_a) > .02) ||
                        ((c_cmaterial->rs > .05) & (c_cmaterial->rd > .05) &&
                                !c_isgrey(&c_cmaterial->rs_c) &&
                                !c_equiv(&c_cmaterial->rd_c, &c_cmaterial->rs_c)) ||
                        color_clash(MG_E_TS, MG_E_TD) ||
                        color_clash(MG_E_TD, MG_E_RD) ||
                        color_clash(MG_E_RD, MG_E_TS)) {
                COLOR   rs_rgb, ts_rgb, td_rgb; /* separate modifier paths */
                char    rs_pname[128], ts_pname[128], td_pname[128];
                strcpy(sgen_str, SGEN_RS);
                strcpy(rs_pname, specolor(rs_rgb, &c_cmaterial->rs_c, c_cmaterial->rs));
                strcpy(sgen_str, SGEN_TS);
                strcpy(ts_pname, specolor(ts_rgb, &c_cmaterial->ts_c, c_cmaterial->ts));
                strcpy(sgen_str, SGEN_TD);
                strcpy(td_pname, specolor(td_rgb, &c_cmaterial->td_c, c_cmaterial->td));
                strcpy(sgen_str, SGEN_DEF);
                pname = specolor(radrgb, &c_cmaterial->rd_c, c_cmaterial->rd);
                if (!strcmp(rs_pname, void_str) && !isgrey(rs_rgb)) {
                        putrgbpat(strcpy(rs_pname,"rs_rgb*"), rs_rgb);
                        colval(rs_rgb,GRN) = 1;
                }
                if (!strcmp(ts_pname, void_str) && !isgrey(ts_rgb)) {
                        putrgbpat(strcpy(ts_pname,"ts_rgb*"), ts_rgb);
                        colval(ts_rgb,GRN) = 1;
                }
                fprintf(matfp, "\n%s WGMDfunc %s\n", pname, mname);
                fprintf(matfp, "13\t%s %f %f %f\n", rs_pname, colval(rs_rgb,GRN),
                                c_cmaterial->rs_a, c_cmaterial->rs_a);
                fprintf(matfp, "\t%s %f %f %f\n", ts_pname, colval(ts_rgb,GRN),
                                c_cmaterial->ts_a, c_cmaterial->ts_a);
                fprintf(matfp, "\t%s\n\t0 0 1 .\n0\n", td_pname);
                fprintf(matfp, "9\t%f %f %f\n", colval(radrgb,RED),
                                colval(radrgb,GRN), colval(radrgb,BLU));
                fprintf(matfp, "\t%f %f %f\n", colval(radrgb,RED),
                                colval(radrgb,GRN), colval(radrgb,BLU));
                fprintf(matfp, "\t%f %f %f\n", colval(td_rgb,RED),
                                colval(td_rgb,GRN), colval(td_rgb,BLU));
                if (c_cmaterial->sided)
                        putsided(mname);
                return(mname);
        }
                                        /* check for trans */
        if (c_cmaterial->td + c_cmaterial->ts > .01) {
                double  a5, a6;
                                                /* average colors */
                d = c_cmaterial->rd + c_cmaterial->td + c_cmaterial->ts;
                cvtcolor(radrgb, &c_cmaterial->rd_c, c_cmaterial->rd/d);
                cvtcolor(c2, &c_cmaterial->td_c, c_cmaterial->td/d);
                addcolor(radrgb, c2);
                cvtcolor(c2, &c_cmaterial->ts_c, c_cmaterial->ts/d);
                addcolor(radrgb, c2);
                if (c_cmaterial->rs + c_cmaterial->ts > .0001)
                        a5 = (c_cmaterial->rs*c_cmaterial->rs_a +
                                        c_cmaterial->ts*c_cmaterial->ts_a) /
                                        (c_cmaterial->rs + c_cmaterial->ts);
                a6 = (c_cmaterial->td + c_cmaterial->ts) /
                                (c_cmaterial->rd + c_cmaterial->td + c_cmaterial->ts);
                if (a6 < .999)
                        d = c_cmaterial->rd/(1. - c_cmaterial->rs)/(1. - a6);
                else
                        d = c_cmaterial->td + c_cmaterial->ts;
                scalecolor(radrgb, d);
                fprintf(matfp, "\nvoid trans %s\n0\n0\n", mname);
                fprintf(matfp, "7 %f %f %f\n", colval(radrgb,RED),
                                colval(radrgb,GRN), colval(radrgb,BLU));
                fprintf(matfp, "\t%f %f %f %f\n", c_cmaterial->rs, a5, a6,
                                c_cmaterial->ts/(c_cmaterial->ts + c_cmaterial->td));
                if (c_cmaterial->sided)
                        putsided(mname);
                return(mname);
        }
                                        /* check for plastic */
        if (c_cmaterial->rs < .1 && (c_cmaterial->rs < .1*c_cmaterial->rd ||
                                        c_isgrey(&c_cmaterial->rs_c))) {
                pname = specolor(radrgb, &c_cmaterial->rd_c,
                                        c_cmaterial->rd/(1.-c_cmaterial->rs));
                fprintf(matfp, "\n%s plastic %s\n0\n0\n", pname, mname);
                fprintf(matfp, "5 %f %f %f %f %f\n", colval(radrgb,RED),
                                colval(radrgb,GRN), colval(radrgb,BLU),
                                c_cmaterial->rs, c_cmaterial->rs_a);
                if (c_cmaterial->sided)
                        putsided(mname);
                return(mname);
        }
                                        /* else it's metal */
                                                /* compute color */
        if (c_equiv(&c_cmaterial->rd_c, &c_cmaterial->rs_c)) {
                pname = specolor(radrgb, &c_cmaterial->rs_c, c_cmaterial->rs+c_cmaterial->rd);
        } else if (c_cmaterial->rd <= .05f) {
                pname = specolor(radrgb, &c_cmaterial->rs_c, c_cmaterial->rs);
                cvtcolor(c2, &c_cmaterial->rd_c, c_cmaterial->rd);
                addcolor(radrgb, c2);
        } else {
                pname = "void";
                cvtcolor(radrgb, &c_cmaterial->rd_c, c_cmaterial->rd);
                cvtcolor(c2, &c_cmaterial->rs_c, c_cmaterial->rs);
                addcolor(radrgb, c2);
        }
        fprintf(matfp, "\n%s metal %s\n0\n0\n", pname, mname);
        fprintf(matfp, "5 %f %f %f %f %f\n", colval(radrgb,RED),
                        colval(radrgb,GRN), colval(radrgb,BLU),
                        c_cmaterial->rs/(c_cmaterial->rd + c_cmaterial->rs),
                        c_cmaterial->rs_a);
        if (c_cmaterial->sided)
                putsided(mname);
        return(mname);
}


void
cvtcolor(       /* convert a CIE XYZ color to RGB */
        COLOR   radrgb,
        C_COLOR *ciec,
        double  intensity
)
{
        COLOR   ciexyz;

        if (intensity <= 0) {
                setcolor(radrgb, 0, 0, 0);
                return;
        }
        c_ccvt(ciec, C_CSXY);           /* get xy representation */
        ciexyz[1] = intensity;
        ciexyz[0] = ciec->cx/ciec->cy*ciexyz[1];
        ciexyz[2] = ciexyz[1]*(1./ciec->cy - 1.) - ciexyz[0];
        cie_rgb(radrgb, ciexyz);
}


int color_clash(        /* do non-zero material components clash? */
        int e1,
        int e2
)
{
        C_COLOR *c1;

        if (e1 == e2)
                return(0);
        switch (e1) {
        case MG_E_RD:
                if (c_cmaterial->rd <= .01) return(0);
                c1 = &c_cmaterial->rd_c;
                break;
        case MG_E_RS:
                if (c_cmaterial->rs <= .01) return(0);
                c1 = &c_cmaterial->rs_c;
                break;
        case MG_E_TD:
                if (c_cmaterial->td <= .01) return(0);
                c1 = &c_cmaterial->td_c;
                break;
        case MG_E_TS:
                if (c_cmaterial->ts <= .01) return(0);
                c1 = &c_cmaterial->ts_c;
                break;
        default:
                return(0);
        }
        switch (e2) {
        case MG_E_RD:
                if (c_cmaterial->rd <= .01) return(0);
                return(!c_equiv(c1, &c_cmaterial->rd_c));
        case MG_E_RS:
                if (c_cmaterial->rs <= .01) return(0);
                return(!c_equiv(c1, &c_cmaterial->rs_c));
        case MG_E_TD:
                if (c_cmaterial->td <= .01) return(0);
                return(!c_equiv(c1, &c_cmaterial->td_c));
        case MG_E_TS:
                if (c_cmaterial->ts <= .01) return(0);
                return(!c_equiv(c1, &c_cmaterial->ts_c));
        }
        return(0);
}


static int      /* new spectrum definition? */
newspecdef(C_COLOR *spc)
{
        static LUTAB    spc_tab = LU_SINIT(NULL,free);
        LUENT   *lp = lu_find(&spc_tab, (const char *)spc->client_data);

        if (lp == NULL)                 /* should never happen */
                return(1);
        if (lp->data == NULL) {         /* new entry */
                lp->key = (char *)spc->client_data;
                lp->data = (char *)malloc(sizeof(C_COLOR));
        } else if (c_equiv(spc, (C_COLOR *)lp->data))
                return(0);              /* unchanged */

        if (lp->data != NULL)           /* else remember if we can */
                *(C_COLOR *)lp->data = *spc;
        return(1);                      /* good as new */
}


char *
specolor(       /* check if color has spectra and output accordingly */
        COLOR   radrgb,
        C_COLOR *clr,
        double  intensity
)
{
        static char     spname[128];
        double  mult;
        int     cbeg, cend, i;

        if (!dospectra | !(clr->flags & C_CDSPEC) | (intensity <= FTINY)) {
                cvtcolor(radrgb, clr, intensity);
                return(void_str);               /* just use RGB */
        }
        setcolor(radrgb, intensity, intensity, intensity);
        for (cbeg = 0; cbeg < C_CNSS; cbeg++)   /* trim zeros off beginning */
                if (clr->ssamp[cbeg])
                        break;
        if (cbeg >= C_CNSS)                     /* should never happen! */
                return(void_str);
        if (clr->client_data != NULL) {         /* get name if available */
                strcpy(spname, (char *)clr->client_data);
                strcat(spname, "*");            /* make sure it's special */
                if (!newspecdef(clr))           /* output already? */
                        return(spname);
        } else
                strcpy(spname, sgen_str);
        c_ccvt(clr, C_CSEFF);                   /* else output spectrum prim */
        for (cend = 0; !clr->ssamp[C_CNSS-1-cend]; cend++)
                ;                               /* trim zeros off end */
        fprintf(matfp, "\nvoid spectrum %s\n0\n0\n", spname);
        fprintf(matfp, "%d %d %d", C_CNSS+2-cbeg-cend,
                C_CMINWL+cbeg*C_CWLI, C_CMAXWL-cend*C_CWLI);
        mult = (C_CNSS*c_dfcolor.eff)/(clr->ssum*clr->eff);
        for (i = cbeg; i < C_CNSS-cend; i++) {
                if (!((i-cbeg+1)%6)) fputc('\n', matfp);
                fprintf(matfp, "\t%.5f", clr->ssamp[i]*mult);
        }
        fputc('\n', matfp);
        return(spname);
}


int
isgrey(                         /* is RGB close match to grey? */
        COLOR rgb
)
{
        const double    yv = bright(rgb);
        double          diff2 = 0;
        int             i;

        for (i = 3; i--; ) {
                double  d = yv - colval(rgb,i);
                diff2 += d*d;
        }
        return(diff2 <= yv*yv*0.0025);
}


void
putrgbpat(                      /* put out RGB pattern with given name */
        char *pnm,
        COLOR rgb
)
{
        fprintf(matfp, "\nvoid colorfunc %s\n", pnm);
        fprintf(matfp, "4 %f %f %f .\n0\n0\n", colval(rgb,RED),
                        colval(rgb,GRN), colval(rgb,BLU));
}


char *
object(void)                    /* return current object name */
{
        static char     objbuf[64];
        int     i;
        char    *cp;
        int     len;
                                                /* tracked by obj_handler */
        i = obj_nnames - sizeof(objbuf)/16;
        if (i < 0)
                i = 0;
        for (cp = objbuf; i < obj_nnames &&
                cp + (len=strlen(obj_name[i])) < objbuf+sizeof(objbuf)-1;
                        i++, *cp++ = '.') {
                strcpy(cp, obj_name[i]);
                cp += len;
        }
        *cp = '\0';
        return(objbuf);
}


char *
addarg(                         /* add argument and advance pointer */
        char *op,
        char *arg
)
{
        *op = ' ';
        while ( (*++op = *arg++) )
                ;
        return(op);
}
Revision:	2.36
Committed:	Fri May 23 17:02:07 2025 UTC (6 days, 21 hours ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 2.35:	+141 -6 lines
Log Message:	feat(mgf2rad): Added support of WGMDfunc material for different spectral components