cv/mgflib/context.c

/* Copyright (c) 1997 Regents of the University of California */

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

/*
 * Context handlers
 */

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

                                /* default context values */
static C_COLOR          c_dfcolor = C_DEFCOLOR;
static C_MATERIAL       c_dfmaterial = C_DEFMATERIAL;
static C_VERTEX         c_dfvertex = C_DEFVERTEX;

                                /* the unnamed contexts */
static C_COLOR          c_uncolor = C_DEFCOLOR;
static C_MATERIAL       c_unmaterial = C_DEFMATERIAL;
static C_VERTEX         c_unvertex = C_DEFVERTEX;

                                /* the current contexts */
C_COLOR         *c_ccolor = &c_uncolor;
char            *c_ccname = NULL;
C_MATERIAL      *c_cmaterial = &c_unmaterial;
char            *c_cmname = NULL;
C_VERTEX        *c_cvertex = &c_unvertex;
char            *c_cvname = NULL;

static LUTAB    clr_tab = LU_SINIT(free,free);  /* color lookup table */
static LUTAB    mat_tab = LU_SINIT(free,free);  /* material lookup table */
static LUTAB    vtx_tab = LU_SINIT(free,free);  /* vertex lookup table */

                                /* CIE 1931 Standard Observer curves */
static C_COLOR  cie_xf = { 1, NULL, C_CDSPEC|C_CSSPEC|C_CSXY|C_CSEFF,
                        {14,42,143,435,1344,2839,3483,3362,2908,1954,956,
                        320,49,93,633,1655,2904,4334,5945,7621,9163,10263,
                        10622,10026,8544,6424,4479,2835,1649,874,468,227,
                        114,58,29,14,7,3,2,1,0}, 106836L, .467, .368, 362.230
                        };
static C_COLOR  cie_yf = { 1, NULL, C_CDSPEC|C_CSSPEC|C_CSXY|C_CSEFF,
                        {0,1,4,12,40,116,230,380,600,910,1390,2080,3230,
                        5030,7100,8620,9540,9950,9950,9520,8700,7570,6310,
                        5030,3810,2650,1750,1070,610,320,170,82,41,21,10,
                        5,2,1,1,0,0}, 106856L, .398, .542, 493.525
                        };
static C_COLOR  cie_zf = { 1, NULL, C_CDSPEC|C_CSSPEC|C_CSXY|C_CSEFF,
                        {65,201,679,2074,6456,13856,17471,17721,16692,
                        12876,8130,4652,2720,1582,782,422,203,87,39,21,17,
                        11,8,3,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
                        106770L, .147, .077, 54.363
                        };
                                /* Derived CIE 1931 Primaries (imaginary) */
static C_COLOR  cie_xp = { 1, NULL, C_CDSPEC|C_CSSPEC|C_CSXY,
                        {-174,-198,-195,-197,-202,-213,-235,-272,-333,
                        -444,-688,-1232,-2393,-4497,-6876,-6758,-5256,
                        -3100,-815,1320,3200,4782,5998,6861,7408,7754,
                        7980,8120,8199,8240,8271,8292,8309,8283,8469,
                        8336,8336,8336,8336,8336,8336},
                        127424L, 1., .0,
                        };
static C_COLOR  cie_yp = { 1, NULL, C_CDSPEC|C_CSSPEC|C_CSXY,
                        {-451,-431,-431,-430,-427,-417,-399,-366,-312,
                        -204,57,691,2142,4990,8810,9871,9122,7321,5145,
                        3023,1123,-473,-1704,-2572,-3127,-3474,-3704,
                        -3846,-3927,-3968,-3999,-4021,-4038,-4012,-4201,
                        -4066,-4066,-4066,-4066,-4066,-4066},
                        -23035L, .0, 1.,
                        };
static C_COLOR  cie_zp = { 1, NULL, C_CDSPEC|C_CSSPEC|C_CSXY,
                        {4051,4054,4052,4053,4054,4056,4059,4064,4071,
                        4074,4056,3967,3677,2933,1492,313,-440,-795,
                        -904,-918,-898,-884,-869,-863,-855,-855,-851,
                        -848,-847,-846,-846,-846,-845,-846,-843,-845,
                        -845,-845,-845,-845,-845},
                        36057L, .0, .0,
                        };

static int      setspectrum();
static int      setbbtemp();
static void     mixcolors();


int
c_hcolor(ac, av)                /* handle color entity */
int     ac;
register char   **av;
{
        double  w, wsum;
        register int    i;
        register LUENT  *lp;

        switch (mg_entity(av[0])) {
        case MG_E_COLOR:        /* get/set color context */
                if (ac > 4)
                        return(MG_EARGC);
                if (ac == 1) {          /* set unnamed color context */
                        c_uncolor = c_dfcolor;
                        c_ccolor = &c_uncolor;
                        c_ccname = NULL;
                        return(MG_OK);
                }
                if (!isname(av[1]))
                        return(MG_EILL);
                lp = lu_find(&clr_tab, av[1]);  /* lookup context */
                if (lp == NULL)
                        return(MG_EMEM);
                c_ccname = lp->key;
                c_ccolor = (C_COLOR *)lp->data;
                if (ac == 2) {          /* reestablish previous context */
                        if (c_ccolor == NULL)
                                return(MG_EUNDEF);
                        return(MG_OK);
                }
                if (av[2][0] != '=' || av[2][1])
                        return(MG_ETYPE);
                if (c_ccolor == NULL) { /* create new color context */
                        lp->key = (char *)malloc(strlen(av[1])+1);
                        if (lp->key == NULL)
                                return(MG_EMEM);
                        strcpy(lp->key, av[1]);
                        lp->data = (char *)malloc(sizeof(C_COLOR));
                        if (lp->data == NULL)
                                return(MG_EMEM);
                        c_ccname = lp->key;
                        c_ccolor = (C_COLOR *)lp->data;
                        c_ccolor->clock = 0;
                        c_ccolor->client_data = NULL;
                }
                i = c_ccolor->clock;
                if (ac == 3) {          /* use default template */
                        *c_ccolor = c_dfcolor;
                        c_ccolor->clock = i + 1;
                        return(MG_OK);
                }
                lp = lu_find(&clr_tab, av[3]);  /* lookup template */
                if (lp == NULL)
                        return(MG_EMEM);
                if (lp->data == NULL)
                        return(MG_EUNDEF);
                *c_ccolor = *(C_COLOR *)lp->data;
                c_ccolor->clock = i + 1;
                return(MG_OK);
        case MG_E_CXY:          /* assign CIE XY value */
                if (ac != 3)
                        return(MG_EARGC);
                if (!isflt(av[1]) | !isflt(av[2]))
                        return(MG_ETYPE);
                c_ccolor->cx = atof(av[1]);
                c_ccolor->cy = atof(av[2]);
                c_ccolor->flags = C_CDXY|C_CSXY;
                if (c_ccolor->cx < 0. | c_ccolor->cy < 0. |
                                c_ccolor->cx + c_ccolor->cy > 1.)
                        return(MG_EILL);
                c_ccolor->clock++;
                return(MG_OK);
        case MG_E_CSPEC:        /* assign spectral values */
                if (ac < 5)
                        return(MG_EARGC);
                if (!isflt(av[1]) | !isflt(av[2]))
                        return(MG_ETYPE);
                return(setspectrum(c_ccolor, atof(av[1]), atof(av[2]),
                                ac-3, av+3));
        case MG_E_CCT:          /* assign black body spectrum */
                if (ac != 2)
                        return(MG_EARGC);
                if (!isflt(av[1]))
                        return(MG_ETYPE);
                return(setbbtemp(c_ccolor, atof(av[1])));
        case MG_E_CMIX:         /* mix colors */
                if (ac < 5 || (ac-1)%2)
                        return(MG_EARGC);
                if (!isflt(av[1]))
                        return(MG_ETYPE);
                wsum = atof(av[1]);
                if ((lp = lu_find(&clr_tab, av[2])) == NULL)
                        return(MG_EMEM);
                if (lp->data == NULL)
                        return(MG_EUNDEF);
                *c_ccolor = *(C_COLOR *)lp->data;
                for (i = 3; i < ac; i += 2) {
                        if (!isflt(av[i]))
                                return(MG_ETYPE);
                        w = atof(av[i]);
                        if ((lp = lu_find(&clr_tab, av[i+1])) == NULL)
                                return(MG_EMEM);
                        if (lp->data == NULL)
                                return(MG_EUNDEF);
                        mixcolors(c_ccolor, wsum, c_ccolor,
                                        w, (C_COLOR *)lp->data);
                        wsum += w;
                }
                if (wsum <= 0.)
                        return(MG_EILL);
                c_ccolor->clock++;
                return(MG_OK);
        }
        return(MG_EUNK);
}


int
c_hmaterial(ac, av)             /* handle material entity */
int     ac;
register char   **av;
{
        int     i;
        register LUENT  *lp;

        switch (mg_entity(av[0])) {
        case MG_E_MATERIAL:     /* get/set material context */
                if (ac > 4)
                        return(MG_EARGC);
                if (ac == 1) {          /* set unnamed material context */
                        c_unmaterial = c_dfmaterial;
                        c_cmaterial = &c_unmaterial;
                        c_cmname = NULL;
                        return(MG_OK);
                }
                if (!isname(av[1]))
                        return(MG_EILL);
                lp = lu_find(&mat_tab, av[1]);  /* lookup context */
                if (lp == NULL)
                        return(MG_EMEM);
                c_cmname = lp->key;
                c_cmaterial = (C_MATERIAL *)lp->data;
                if (ac == 2) {          /* reestablish previous context */
                        if (c_cmaterial == NULL)
                                return(MG_EUNDEF);
                        return(MG_OK);
                }
                if (av[2][0] != '=' || av[2][1])
                        return(MG_ETYPE);
                if (c_cmaterial == NULL) {      /* create new material */
                        lp->key = (char *)malloc(strlen(av[1])+1);
                        if (lp->key == NULL)
                                return(MG_EMEM);
                        strcpy(lp->key, av[1]);
                        lp->data = (char *)malloc(sizeof(C_MATERIAL));
                        if (lp->data == NULL)
                                return(MG_EMEM);
                        c_cmname = lp->key;
                        c_cmaterial = (C_MATERIAL *)lp->data;
                        c_cmaterial->clock = 0;
                        c_cmaterial->client_data = NULL;
                }
                i = c_cmaterial->clock;
                if (ac == 3) {          /* use default template */
                        *c_cmaterial = c_dfmaterial;
                        c_cmaterial->clock = i + 1;
                        return(MG_OK);
                }
                lp = lu_find(&mat_tab, av[3]);  /* lookup template */
                if (lp == NULL)
                        return(MG_EMEM);
                if (lp->data == NULL)
                        return(MG_EUNDEF);
                *c_cmaterial = *(C_MATERIAL *)lp->data;
                c_cmaterial->clock = i + 1;
                return(MG_OK);
        case MG_E_IR:           /* set index of refraction */
                if (ac != 3)
                        return(MG_EARGC);
                if (!isflt(av[1]) | !isflt(av[2]))
                        return(MG_ETYPE);
                c_cmaterial->nr = atof(av[1]);
                c_cmaterial->ni = atof(av[2]);
                if (c_cmaterial->nr <= FTINY)
                        return(MG_EILL);
                c_cmaterial->clock++;
                return(MG_OK);
        case MG_E_RD:           /* set diffuse reflectance */
                if (ac != 2)
                        return(MG_EARGC);
                if (!isflt(av[1]))
                        return(MG_ETYPE);
                c_cmaterial->rd = atof(av[1]);
                if (c_cmaterial->rd < 0. | c_cmaterial->rd > 1.)
                        return(MG_EILL);
                c_cmaterial->rd_c = *c_ccolor;
                c_cmaterial->clock++;
                return(MG_OK);
        case MG_E_ED:           /* set diffuse emittance */
                if (ac != 2)
                        return(MG_EARGC);
                if (!isflt(av[1]))
                        return(MG_ETYPE);
                c_cmaterial->ed = atof(av[1]);
                if (c_cmaterial->ed < 0.)
                        return(MG_EILL);
                c_cmaterial->ed_c = *c_ccolor;
                c_cmaterial->clock++;
                return(MG_OK);
        case MG_E_TD:           /* set diffuse transmittance */
                if (ac != 2)
                        return(MG_EARGC);
                if (!isflt(av[1]))
                        return(MG_ETYPE);
                c_cmaterial->td = atof(av[1]);
                if (c_cmaterial->td < 0. | c_cmaterial->td > 1.)
                        return(MG_EILL);
                c_cmaterial->td_c = *c_ccolor;
                c_cmaterial->clock++;
                return(MG_OK);
        case MG_E_RS:           /* set specular reflectance */
                if (ac != 3)
                        return(MG_EARGC);
                if (!isflt(av[1]) | !isflt(av[2]))
                        return(MG_ETYPE);
                c_cmaterial->rs = atof(av[1]);
                c_cmaterial->rs_a = atof(av[2]);
                if (c_cmaterial->rs < 0. | c_cmaterial->rs > 1. |
                                c_cmaterial->rs_a < 0.)
                        return(MG_EILL);
                c_cmaterial->rs_c = *c_ccolor;
                c_cmaterial->clock++;
                return(MG_OK);
        case MG_E_TS:           /* set specular transmittance */
                if (ac != 3)
                        return(MG_EARGC);
                if (!isflt(av[1]) | !isflt(av[2]))
                        return(MG_ETYPE);
                c_cmaterial->ts = atof(av[1]);
                c_cmaterial->ts_a = atof(av[2]);
                if (c_cmaterial->ts < 0. | c_cmaterial->ts > 1. |
                                c_cmaterial->ts_a < 0.)
                        return(MG_EILL);
                c_cmaterial->ts_c = *c_ccolor;
                c_cmaterial->clock++;
                return(MG_OK);
        case MG_E_SIDES:        /* set number of sides */
                if (ac != 2)
                        return(MG_EARGC);
                if (!isint(av[1]))
                        return(MG_ETYPE);
                i = atoi(av[1]);
                if (i == 1)
                        c_cmaterial->sided = 1;
                else if (i == 2)
                        c_cmaterial->sided = 0;
                else
                        return(MG_EILL);
                c_cmaterial->clock++;
                return(MG_OK);
        }
        return(MG_EUNK);
}


int
c_hvertex(ac, av)               /* handle a vertex entity */
int     ac;
register char   **av;
{
        int     i;
        register LUENT  *lp;

        switch (mg_entity(av[0])) {
        case MG_E_VERTEX:       /* get/set vertex context */
                if (ac > 4)
                        return(MG_EARGC);
                if (ac == 1) {          /* set unnamed vertex context */
                        c_unvertex = c_dfvertex;
                        c_cvertex = &c_unvertex;
                        c_cvname = NULL;
                        return(MG_OK);
                }
                if (!isname(av[1]))
                        return(MG_EILL);
                lp = lu_find(&vtx_tab, av[1]);  /* lookup context */
                if (lp == NULL)
                        return(MG_EMEM);
                c_cvname = lp->key;
                c_cvertex = (C_VERTEX *)lp->data;
                if (ac == 2) {          /* reestablish previous context */
                        if (c_cvertex == NULL)
                                return(MG_EUNDEF);
                        return(MG_OK);
                }
                if (av[2][0] != '=' || av[2][1])
                        return(MG_ETYPE);
                if (c_cvertex == NULL) {        /* create new vertex context */
                        lp->key = (char *)malloc(strlen(av[1])+1);
                        if (lp->key == NULL)
                                return(MG_EMEM);
                        strcpy(lp->key, av[1]);
                        lp->data = (char *)malloc(sizeof(C_VERTEX));
                        if (lp->data == NULL)
                                return(MG_EMEM);
                        c_cvname = lp->key;
                        c_cvertex = (C_VERTEX *)lp->data;
                        c_cvertex->clock = 0;
                        c_cvertex->client_data = NULL;
                }
                i = c_cvertex->clock;
                if (ac == 3) {          /* use default template */
                        *c_cvertex = c_dfvertex;
                        c_cvertex->clock = i + 1;
                        return(MG_OK);
                }
                lp = lu_find(&vtx_tab, av[3]);  /* lookup template */
                if (lp == NULL)
                        return(MG_EMEM);
                if (lp->data == NULL)
                        return(MG_EUNDEF);
                *c_cvertex = *(C_VERTEX *)lp->data;
                c_cvertex->clock = i + 1;
                return(MG_OK);
        case MG_E_POINT:        /* set point */
                if (ac != 4)
                        return(MG_EARGC);
                if (!isflt(av[1]) | !isflt(av[2]) | !isflt(av[3]))
                        return(MG_ETYPE);
                c_cvertex->p[0] = atof(av[1]);
                c_cvertex->p[1] = atof(av[2]);
                c_cvertex->p[2] = atof(av[3]);
                c_cvertex->clock++;
                return(MG_OK);
        case MG_E_NORMAL:       /* set normal */
                if (ac != 4)
                        return(MG_EARGC);
                if (!isflt(av[1]) | !isflt(av[2]) | !isflt(av[3]))
                        return(MG_ETYPE);
                c_cvertex->n[0] = atof(av[1]);
                c_cvertex->n[1] = atof(av[2]);
                c_cvertex->n[2] = atof(av[3]);
                (void)normalize(c_cvertex->n);
                c_cvertex->clock++;
                return(MG_OK);
        }
        return(MG_EUNK);
}


void
c_clearall()                    /* empty context tables */
{
        c_uncolor = c_dfcolor;
        c_ccolor = &c_uncolor;
        c_ccname = NULL;
        lu_done(&clr_tab);
        c_unmaterial = c_dfmaterial;
        c_cmaterial = &c_unmaterial;
        c_cmname = NULL;
        lu_done(&mat_tab);
        c_unvertex = c_dfvertex;
        c_cvertex = &c_unvertex;
        c_cvname = NULL;
        lu_done(&vtx_tab);
}


C_MATERIAL *
c_getmaterial(name)             /* get a named material */
char    *name;
{
        register LUENT  *lp;

        if ((lp = lu_find(&mat_tab, name)) == NULL)
                return(NULL);
        return((C_MATERIAL *)lp->data);
}


C_VERTEX *
c_getvert(name)                 /* get a named vertex */
char    *name;
{
        register LUENT  *lp;

        if ((lp = lu_find(&vtx_tab, name)) == NULL)
                return(NULL);
        return((C_VERTEX *)lp->data);
}


C_COLOR *
c_getcolor(name)                /* get a named color */
char    *name;
{
        register LUENT  *lp;

        if ((lp = lu_find(&clr_tab, name)) == NULL)
                return(NULL);
        return((C_COLOR *)lp->data);
}


int
c_isgrey(clr)                   /* check if color is grey */
register C_COLOR        *clr;
{
        if (!(clr->flags & (C_CSXY|C_CSSPEC)))
                return(1);              /* no settings == grey */
        c_ccvt(clr, C_CSXY);
        return(clr->cx >= .323 && clr->cx <= .343 &&
                        clr->cy >= .323 && clr->cy <= .343);
}


void
c_ccvt(clr, fl)                 /* convert color representations */
register C_COLOR        *clr;
int     fl;
{
        double  x, y, z;
        register int    i;

        fl &= ~clr->flags;                      /* ignore what's done */
        if (!fl)                                /* everything's done! */
                return;
        if (!(clr->flags & (C_CSXY|C_CSSPEC)))  /* nothing set! */
                *clr = c_dfcolor;
        if (fl & C_CSXY) {              /* cspec -> cxy */
                x = y = z = 0.;
                for (i = 0; i < C_CNSS; i++) {
                        x += cie_xf.ssamp[i] * clr->ssamp[i];
                        y += cie_yf.ssamp[i] * clr->ssamp[i];
                        z += cie_zf.ssamp[i] * clr->ssamp[i];
                }
                x /= (double)cie_xf.ssum;
                y /= (double)cie_yf.ssum;
                z /= (double)cie_zf.ssum;
                z += x + y;
                clr->cx = x / z;
                clr->cy = y / z;
                clr->flags |= C_CSXY;
        } else if (fl & C_CSSPEC) {     /* cxy -> cspec */
                x = clr->cx;
                y = clr->cy;
                z = 1. - x - y;
                clr->ssum = 0;
                for (i = 0; i < C_CNSS; i++) {
                        clr->ssamp[i] = x*cie_xp.ssamp[i] + y*cie_yp.ssamp[i]
                                        + z*cie_zp.ssamp[i] + .5;
                        if (clr->ssamp[i] < 0)          /* out of gamut! */
                                clr->ssamp[i] = 0;
                        else
                                clr->ssum += clr->ssamp[i];
                }
                clr->flags |= C_CSSPEC;
        }
        if (fl & C_CSEFF) {             /* compute efficacy */
                if (clr->flags & C_CSSPEC) {            /* from spectrum */
                        y = 0.;
                        for (i = 0; i < C_CNSS; i++)
                                y += cie_yf.ssamp[i] * clr->ssamp[i];
                        clr->eff = C_CLPWM * y / clr->ssum;
                } else /* clr->flags & C_CSXY */ {      /* from (x,y) */
                        clr->eff = clr->cx*cie_xf.eff + clr->cy*cie_yf.eff +
                                        (1. - clr->cx - clr->cy)*cie_zf.eff;
                }
                clr->flags |= C_CSEFF;
        }
}


static int
setspectrum(clr, wlmin, wlmax, ac, av)  /* convert a spectrum */
register C_COLOR        *clr;
double  wlmin, wlmax;
int     ac;
char    **av;
{
        double  scale;
        float   va[C_CNSS];
        register int    i, pos;
        int     n, imax;
        int     wl;
        double  wl0, wlstep;
        double  boxpos, boxstep;
                                        /* check bounds */
        if (wlmax <= C_CMINWL | wlmax <= wlmin | wlmin >= C_CMAXWL)
                return(MG_EILL);
        wlstep = (wlmax - wlmin)/(ac-1);
        while (wlmin < C_CMINWL) {
                wlmin += wlstep;
                ac--; av++;
        }
        while (wlmax > C_CMAXWL) {
                wlmax -= wlstep;
                ac--;
        }
        imax = ac;                      /* box filter if necessary */
        boxpos = 0;
        boxstep = 1;
        if (wlstep < C_CWLI) {
                imax = (wlmax - wlmin)/C_CWLI + (1-FTINY);
                boxpos = (wlmin - C_CMINWL)/C_CWLI;
                boxstep = wlstep/C_CWLI;
                wlstep = C_CWLI;
        }
        scale = 0.;                     /* get values and maximum */
        pos = 0;
        for (i = 0; i < imax; i++) {
                va[i] = 0.; n = 0;
                while (boxpos < i+.5 && pos < ac) {
                        if (!isflt(av[pos]))
                                return(MG_ETYPE);
                        va[i] += atof(av[pos++]);
                        n++;
                        boxpos += boxstep;
                }
                if (n > 1)
                        va[i] /= (double)n;
                if (va[i] > scale)
                        scale = va[i];
                else if (va[i] < -scale)
                        scale = -va[i];
        }
        if (scale <= FTINY)
                return(MG_EILL);
        scale = C_CMAXV / scale;
        clr->ssum = 0;                  /* convert to our spacing */
        wl0 = wlmin;
        pos = 0;
        for (i = 0, wl = C_CMINWL; i < C_CNSS; i++, wl += C_CWLI)
                if (wl < wlmin | wl > wlmax)
                        clr->ssamp[i] = 0;
                else {
                        while (wl0 + wlstep < wl+FTINY) {
                                wl0 += wlstep;
                                pos++;
                        }
                        if (wl+FTINY >= wl0 & wl-FTINY <= wl0)
                                clr->ssamp[i] = scale*va[pos] + .5;
                        else            /* interpolate if necessary */
                                clr->ssamp[i] = .5 + scale / wlstep *
                                                ( va[pos]*(wl0+wlstep - wl) +
                                                        va[pos+1]*(wl - wl0) );
                        clr->ssum += clr->ssamp[i];
                }
        clr->flags = C_CDSPEC|C_CSSPEC;
        clr->clock++;
        return(MG_OK);
}


static void
mixcolors(cres, w1, c1, w2, c2) /* mix two colors according to weights given */
register C_COLOR        *cres, *c1, *c2;
double  w1, w2;
{
        double  scale;
        float   cmix[C_CNSS];
        register int    i;

        if ((c1->flags|c2->flags) & C_CDSPEC) {         /* spectral mixing */
                c_ccvt(c1, C_CSSPEC|C_CSEFF);
                c_ccvt(c2, C_CSSPEC|C_CSEFF);
                w1 /= c1->eff*c1->ssum;
                w2 /= c2->eff*c2->ssum;
                scale = 0.;
                for (i = 0; i < C_CNSS; i++) {
                        cmix[i] = w1*c1->ssamp[i] + w2*c2->ssamp[i];
                        if (cmix[i] > scale)
                                scale = cmix[i];
                }
                scale = C_CMAXV / scale;
                cres->ssum = 0;
                for (i = 0; i < C_CNSS; i++)
                        cres->ssum += cres->ssamp[i] = scale*cmix[i] + .5;
                cres->flags = C_CDSPEC|C_CSSPEC;
        } else {                                        /* CIE xy mixing */
                c_ccvt(c1, C_CSXY);
                c_ccvt(c2, C_CSXY);
                scale = w1/c1->cy + w2/c2->cy;
                if (scale == 0.)
                        return;
                scale = 1. / scale;
                cres->cx = (c1->cx*w1/c1->cy + c2->cx*w2/c2->cy) * scale;
                cres->cy = (w1 + w2) * scale;
                cres->flags = C_CDXY|C_CSXY;
        }
}


#define C1              3.741832e-16    /* W-m^2 */
#define C2              1.4388e-2       /* m-K */

#define bbsp(l,t)       (C1/((l)*(l)*(l)*(l)*(l)*(exp(C2/((t)*(l)))-1.)))
#define bblm(t)         (C2/5./(t))

static int
setbbtemp(clr, tk)              /* set black body spectrum */
register C_COLOR        *clr;
double  tk;
{
        double  sf, wl;
        register int    i;

        if (tk < 1000)
                return(MG_EILL);
        wl = bblm(tk);                  /* scalefactor based on peak */
        if (wl < C_CMINWL*1e-9)
                wl = C_CMINWL*1e-9;
        else if (wl > C_CMAXWL*1e-9)
                wl = C_CMAXWL*1e-9;
        sf = C_CMAXV/bbsp(wl,tk);
        clr->ssum = 0;
        for (i = 0; i < C_CNSS; i++) {
                wl = (C_CMINWL + i*C_CWLI)*1e-9;
                clr->ssum += clr->ssamp[i] = sf*bbsp(wl,tk) + .5;
        }
        clr->flags = C_CDSPEC|C_CSSPEC;
        clr->clock++;
        return(MG_OK);
}

#undef  C1
#undef  C2
#undef  bbsp
#undef  bblm
Revision:	1.26
Committed:	Mon Dec 15 09:41:37 1997 UTC (27 years, 10 months ago) by gregl
Content type:	text/plain
Branch:	MAIN
Changes since 1.25:	+1 -0 lines
Log Message:	added stdlib.h for better reliability on some systems
#	User	Rev	Content
1	greg	1.24	/* Copyright (c) 1997 Regents of the University of California */
2	greg	1.1
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* Context handlers
9			*/
10
11			#include <stdio.h>
12	greg	1.2	#include <math.h>
13	gregl	1.26	#include <stdlib.h>
14	greg	1.1	#include <string.h>
15			#include "parser.h"
16			#include "lookup.h"
17
18			/* default context values */
19			static C_COLOR c_dfcolor = C_DEFCOLOR;
20			static C_MATERIAL c_dfmaterial = C_DEFMATERIAL;
21			static C_VERTEX c_dfvertex = C_DEFVERTEX;
22
23			/* the unnamed contexts */
24			static C_COLOR c_uncolor = C_DEFCOLOR;
25			static C_MATERIAL c_unmaterial = C_DEFMATERIAL;
26			static C_VERTEX c_unvertex = C_DEFVERTEX;
27
28			/* the current contexts */
29			C_COLOR *c_ccolor = &c_uncolor;
30	greg	1.12	char *c_ccname = NULL;
31	greg	1.1	C_MATERIAL *c_cmaterial = &c_unmaterial;
32	greg	1.12	char *c_cmname = NULL;
33	greg	1.1	C_VERTEX *c_cvertex = &c_unvertex;
34	greg	1.12	char *c_cvname = NULL;
35	greg	1.1
36	greg	1.3	static LUTAB clr_tab = LU_SINIT(free,free); /* color lookup table */
37			static LUTAB mat_tab = LU_SINIT(free,free); /* material lookup table */
38			static LUTAB vtx_tab = LU_SINIT(free,free); /* vertex lookup table */
39	greg	1.1
40	greg	1.19	/* CIE 1931 Standard Observer curves */
41	gregl	1.25	static C_COLOR cie_xf = { 1, NULL, C_CDSPEC\|C_CSSPEC\|C_CSXY\|C_CSEFF,
42	greg	1.19	{14,42,143,435,1344,2839,3483,3362,2908,1954,956,
43			320,49,93,633,1655,2904,4334,5945,7621,9163,10263,
44			10622,10026,8544,6424,4479,2835,1649,874,468,227,
45			114,58,29,14,7,3,2,1,0}, 106836L, .467, .368, 362.230
46			};
47	gregl	1.25	static C_COLOR cie_yf = { 1, NULL, C_CDSPEC\|C_CSSPEC\|C_CSXY\|C_CSEFF,
48	greg	1.19	{0,1,4,12,40,116,230,380,600,910,1390,2080,3230,
49			5030,7100,8620,9540,9950,9950,9520,8700,7570,6310,
50			5030,3810,2650,1750,1070,610,320,170,82,41,21,10,
51			5,2,1,1,0,0}, 106856L, .398, .542, 493.525
52			};
53	gregl	1.25	static C_COLOR cie_zf = { 1, NULL, C_CDSPEC\|C_CSSPEC\|C_CSXY\|C_CSEFF,
54	greg	1.19	{65,201,679,2074,6456,13856,17471,17721,16692,
55			12876,8130,4652,2720,1582,782,422,203,87,39,21,17,
56			11,8,3,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
57			106770L, .147, .077, 54.363
58			};
59			/* Derived CIE 1931 Primaries (imaginary) */
60	gregl	1.25	static C_COLOR cie_xp = { 1, NULL, C_CDSPEC\|C_CSSPEC\|C_CSXY,
61	greg	1.19	{-174,-198,-195,-197,-202,-213,-235,-272,-333,
62			-444,-688,-1232,-2393,-4497,-6876,-6758,-5256,
63			-3100,-815,1320,3200,4782,5998,6861,7408,7754,
64			7980,8120,8199,8240,8271,8292,8309,8283,8469,
65			8336,8336,8336,8336,8336,8336},
66			127424L, 1., .0,
67			};
68	gregl	1.25	static C_COLOR cie_yp = { 1, NULL, C_CDSPEC\|C_CSSPEC\|C_CSXY,
69	greg	1.19	{-451,-431,-431,-430,-427,-417,-399,-366,-312,
70			-204,57,691,2142,4990,8810,9871,9122,7321,5145,
71			3023,1123,-473,-1704,-2572,-3127,-3474,-3704,
72			-3846,-3927,-3968,-3999,-4021,-4038,-4012,-4201,
73			-4066,-4066,-4066,-4066,-4066,-4066},
74			-23035L, .0, 1.,
75			};
76	gregl	1.25	static C_COLOR cie_zp = { 1, NULL, C_CDSPEC\|C_CSSPEC\|C_CSXY,
77	greg	1.19	{4051,4054,4052,4053,4054,4056,4059,4064,4071,
78			4074,4056,3967,3677,2933,1492,313,-440,-795,
79			-904,-918,-898,-884,-869,-863,-855,-855,-851,
80			-848,-847,-846,-846,-846,-845,-846,-843,-845,
81			-845,-845,-845,-845,-845},
82			36057L, .0, .0,
83			};
84	greg	1.1
85	greg	1.5	static int setspectrum();
86	greg	1.18	static int setbbtemp();
87	greg	1.5	static void mixcolors();
88
89
90	greg	1.1	int
91			c_hcolor(ac, av) /* handle color entity */
92			int ac;
93			register char **av;
94			{
95	greg	1.5	double w, wsum;
96			register int i;
97	greg	1.1	register LUENT *lp;
98
99			switch (mg_entity(av[0])) {
100			case MG_E_COLOR: /* get/set color context */
101	greg	1.4	if (ac > 4)
102			return(MG_EARGC);
103	greg	1.1	if (ac == 1) { /* set unnamed color context */
104			c_uncolor = c_dfcolor;
105			c_ccolor = &c_uncolor;
106	greg	1.12	c_ccname = NULL;
107	greg	1.1	return(MG_OK);
108			}
109	greg	1.22	if (!isname(av[1]))
110			return(MG_EILL);
111	greg	1.1	lp = lu_find(&clr_tab, av[1]); /* lookup context */
112			if (lp == NULL)
113			return(MG_EMEM);
114	greg	1.14	c_ccname = lp->key;
115	greg	1.9	c_ccolor = (C_COLOR *)lp->data;
116	greg	1.1	if (ac == 2) { /* reestablish previous context */
117	greg	1.9	if (c_ccolor == NULL)
118	greg	1.1	return(MG_EUNDEF);
119			return(MG_OK);
120			}
121			if (av[2][0] != '=' \|\| av[2][1])
122			return(MG_ETYPE);
123	greg	1.9	if (c_ccolor == NULL) { /* create new color context */
124	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
125			if (lp->key == NULL)
126			return(MG_EMEM);
127			strcpy(lp->key, av[1]);
128			lp->data = (char *)malloc(sizeof(C_COLOR));
129			if (lp->data == NULL)
130			return(MG_EMEM);
131	greg	1.14	c_ccname = lp->key;
132	greg	1.9	c_ccolor = (C_COLOR *)lp->data;
133			c_ccolor->clock = 0;
134	gregl	1.25	c_ccolor->client_data = NULL;
135	greg	1.1	}
136	greg	1.10	i = c_ccolor->clock;
137	greg	1.1	if (ac == 3) { /* use default template */
138			*c_ccolor = c_dfcolor;
139	greg	1.9	c_ccolor->clock = i + 1;
140	greg	1.1	return(MG_OK);
141			}
142			lp = lu_find(&clr_tab, av[3]); /* lookup template */
143			if (lp == NULL)
144			return(MG_EMEM);
145			if (lp->data == NULL)
146			return(MG_EUNDEF);
147			c_ccolor = (C_COLOR *)lp->data;
148	greg	1.9	c_ccolor->clock = i + 1;
149	greg	1.1	return(MG_OK);
150			case MG_E_CXY: /* assign CIE XY value */
151			if (ac != 3)
152			return(MG_EARGC);
153	greg	1.18	if (!isflt(av[1]) \| !isflt(av[2]))
154	greg	1.1	return(MG_ETYPE);
155			c_ccolor->cx = atof(av[1]);
156			c_ccolor->cy = atof(av[2]);
157	greg	1.5	c_ccolor->flags = C_CDXY\|C_CSXY;
158	greg	1.1	if (c_ccolor->cx < 0. \| c_ccolor->cy < 0. \|
159			c_ccolor->cx + c_ccolor->cy > 1.)
160			return(MG_EILL);
161	greg	1.8	c_ccolor->clock++;
162	greg	1.1	return(MG_OK);
163	greg	1.5	case MG_E_CSPEC: /* assign spectral values */
164			if (ac < 5)
165			return(MG_EARGC);
166	greg	1.18	if (!isflt(av[1]) \| !isflt(av[2]))
167	greg	1.5	return(MG_ETYPE);
168	greg	1.17	return(setspectrum(c_ccolor, atof(av[1]), atof(av[2]),
169	greg	1.5	ac-3, av+3));
170	greg	1.18	case MG_E_CCT: /* assign black body spectrum */
171			if (ac != 2)
172			return(MG_EARGC);
173			if (!isflt(av[1]))
174			return(MG_ETYPE);
175			return(setbbtemp(c_ccolor, atof(av[1])));
176	greg	1.5	case MG_E_CMIX: /* mix colors */
177			if (ac < 5 \|\| (ac-1)%2)
178			return(MG_EARGC);
179			if (!isflt(av[1]))
180			return(MG_ETYPE);
181			wsum = atof(av[1]);
182			if ((lp = lu_find(&clr_tab, av[2])) == NULL)
183			return(MG_EMEM);
184			if (lp->data == NULL)
185			return(MG_EUNDEF);
186			c_ccolor = (C_COLOR *)lp->data;
187			for (i = 3; i < ac; i += 2) {
188			if (!isflt(av[i]))
189			return(MG_ETYPE);
190			w = atof(av[i]);
191			if ((lp = lu_find(&clr_tab, av[i+1])) == NULL)
192			return(MG_EMEM);
193			if (lp->data == NULL)
194			return(MG_EUNDEF);
195			mixcolors(c_ccolor, wsum, c_ccolor,
196			w, (C_COLOR *)lp->data);
197			wsum += w;
198			}
199	greg	1.24	if (wsum <= 0.)
200			return(MG_EILL);
201	greg	1.10	c_ccolor->clock++;
202	greg	1.5	return(MG_OK);
203	greg	1.1	}
204			return(MG_EUNK);
205			}
206
207
208			int
209			c_hmaterial(ac, av) /* handle material entity */
210			int ac;
211			register char **av;
212			{
213	greg	1.9	int i;
214	greg	1.1	register LUENT *lp;
215
216			switch (mg_entity(av[0])) {
217			case MG_E_MATERIAL: /* get/set material context */
218	greg	1.4	if (ac > 4)
219			return(MG_EARGC);
220	greg	1.1	if (ac == 1) { /* set unnamed material context */
221			c_unmaterial = c_dfmaterial;
222			c_cmaterial = &c_unmaterial;
223	greg	1.12	c_cmname = NULL;
224	greg	1.1	return(MG_OK);
225			}
226	greg	1.22	if (!isname(av[1]))
227			return(MG_EILL);
228	greg	1.1	lp = lu_find(&mat_tab, av[1]); /* lookup context */
229			if (lp == NULL)
230			return(MG_EMEM);
231	greg	1.14	c_cmname = lp->key;
232	greg	1.9	c_cmaterial = (C_MATERIAL *)lp->data;
233	greg	1.1	if (ac == 2) { /* reestablish previous context */
234	greg	1.9	if (c_cmaterial == NULL)
235	greg	1.1	return(MG_EUNDEF);
236			return(MG_OK);
237			}
238			if (av[2][0] != '=' \|\| av[2][1])
239			return(MG_ETYPE);
240	greg	1.9	if (c_cmaterial == NULL) { /* create new material */
241	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
242			if (lp->key == NULL)
243			return(MG_EMEM);
244			strcpy(lp->key, av[1]);
245			lp->data = (char *)malloc(sizeof(C_MATERIAL));
246			if (lp->data == NULL)
247			return(MG_EMEM);
248	greg	1.14	c_cmname = lp->key;
249	greg	1.9	c_cmaterial = (C_MATERIAL *)lp->data;
250			c_cmaterial->clock = 0;
251	gregl	1.25	c_cmaterial->client_data = NULL;
252	greg	1.1	}
253	greg	1.10	i = c_cmaterial->clock;
254	greg	1.1	if (ac == 3) { /* use default template */
255			*c_cmaterial = c_dfmaterial;
256	greg	1.9	c_cmaterial->clock = i + 1;
257	greg	1.1	return(MG_OK);
258			}
259			lp = lu_find(&mat_tab, av[3]); /* lookup template */
260			if (lp == NULL)
261			return(MG_EMEM);
262			if (lp->data == NULL)
263			return(MG_EUNDEF);
264			c_cmaterial = (C_MATERIAL *)lp->data;
265	greg	1.9	c_cmaterial->clock = i + 1;
266	greg	1.1	return(MG_OK);
267	greg	1.21	case MG_E_IR: /* set index of refraction */
268			if (ac != 3)
269			return(MG_EARGC);
270			if (!isflt(av[1]) \| !isflt(av[2]))
271			return(MG_ETYPE);
272			c_cmaterial->nr = atof(av[1]);
273			c_cmaterial->ni = atof(av[2]);
274			if (c_cmaterial->nr <= FTINY)
275			return(MG_EILL);
276			c_cmaterial->clock++;
277			return(MG_OK);
278	greg	1.1	case MG_E_RD: /* set diffuse reflectance */
279			if (ac != 2)
280			return(MG_EARGC);
281			if (!isflt(av[1]))
282			return(MG_ETYPE);
283			c_cmaterial->rd = atof(av[1]);
284			if (c_cmaterial->rd < 0. \| c_cmaterial->rd > 1.)
285			return(MG_EILL);
286			c_cmaterial->rd_c = *c_ccolor;
287	greg	1.2	c_cmaterial->clock++;
288	greg	1.1	return(MG_OK);
289			case MG_E_ED: /* set diffuse emittance */
290			if (ac != 2)
291			return(MG_EARGC);
292			if (!isflt(av[1]))
293			return(MG_ETYPE);
294			c_cmaterial->ed = atof(av[1]);
295			if (c_cmaterial->ed < 0.)
296			return(MG_EILL);
297			c_cmaterial->ed_c = *c_ccolor;
298	greg	1.2	c_cmaterial->clock++;
299	greg	1.1	return(MG_OK);
300			case MG_E_TD: /* set diffuse transmittance */
301			if (ac != 2)
302			return(MG_EARGC);
303			if (!isflt(av[1]))
304			return(MG_ETYPE);
305			c_cmaterial->td = atof(av[1]);
306			if (c_cmaterial->td < 0. \| c_cmaterial->td > 1.)
307			return(MG_EILL);
308			c_cmaterial->td_c = *c_ccolor;
309	greg	1.8	c_cmaterial->clock++;
310	greg	1.1	return(MG_OK);
311			case MG_E_RS: /* set specular reflectance */
312			if (ac != 3)
313			return(MG_EARGC);
314	greg	1.18	if (!isflt(av[1]) \| !isflt(av[2]))
315	greg	1.1	return(MG_ETYPE);
316			c_cmaterial->rs = atof(av[1]);
317			c_cmaterial->rs_a = atof(av[2]);
318			if (c_cmaterial->rs < 0. \| c_cmaterial->rs > 1. \|
319			c_cmaterial->rs_a < 0.)
320			return(MG_EILL);
321			c_cmaterial->rs_c = *c_ccolor;
322	greg	1.2	c_cmaterial->clock++;
323	greg	1.1	return(MG_OK);
324			case MG_E_TS: /* set specular transmittance */
325			if (ac != 3)
326			return(MG_EARGC);
327	greg	1.18	if (!isflt(av[1]) \| !isflt(av[2]))
328	greg	1.1	return(MG_ETYPE);
329			c_cmaterial->ts = atof(av[1]);
330			c_cmaterial->ts_a = atof(av[2]);
331			if (c_cmaterial->ts < 0. \| c_cmaterial->ts > 1. \|
332			c_cmaterial->ts_a < 0.)
333			return(MG_EILL);
334			c_cmaterial->ts_c = *c_ccolor;
335	greg	1.2	c_cmaterial->clock++;
336	greg	1.1	return(MG_OK);
337	greg	1.13	case MG_E_SIDES: /* set number of sides */
338			if (ac != 2)
339			return(MG_EARGC);
340			if (!isint(av[1]))
341			return(MG_ETYPE);
342			i = atoi(av[1]);
343			if (i == 1)
344			c_cmaterial->sided = 1;
345			else if (i == 2)
346			c_cmaterial->sided = 0;
347			else
348			return(MG_EILL);
349			c_cmaterial->clock++;
350			return(MG_OK);
351	greg	1.1	}
352			return(MG_EUNK);
353			}
354
355
356			int
357			c_hvertex(ac, av) /* handle a vertex entity */
358			int ac;
359			register char **av;
360			{
361	greg	1.9	int i;
362	greg	1.1	register LUENT *lp;
363
364			switch (mg_entity(av[0])) {
365			case MG_E_VERTEX: /* get/set vertex context */
366	greg	1.4	if (ac > 4)
367			return(MG_EARGC);
368	greg	1.1	if (ac == 1) { /* set unnamed vertex context */
369			c_unvertex = c_dfvertex;
370			c_cvertex = &c_unvertex;
371	greg	1.12	c_cvname = NULL;
372	greg	1.1	return(MG_OK);
373			}
374	greg	1.22	if (!isname(av[1]))
375			return(MG_EILL);
376	greg	1.1	lp = lu_find(&vtx_tab, av[1]); /* lookup context */
377			if (lp == NULL)
378			return(MG_EMEM);
379	greg	1.14	c_cvname = lp->key;
380	greg	1.9	c_cvertex = (C_VERTEX *)lp->data;
381	greg	1.1	if (ac == 2) { /* reestablish previous context */
382	greg	1.9	if (c_cvertex == NULL)
383	greg	1.1	return(MG_EUNDEF);
384			return(MG_OK);
385			}
386			if (av[2][0] != '=' \|\| av[2][1])
387			return(MG_ETYPE);
388	greg	1.9	if (c_cvertex == NULL) { /* create new vertex context */
389	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
390			if (lp->key == NULL)
391			return(MG_EMEM);
392			strcpy(lp->key, av[1]);
393			lp->data = (char *)malloc(sizeof(C_VERTEX));
394			if (lp->data == NULL)
395			return(MG_EMEM);
396	greg	1.14	c_cvname = lp->key;
397	greg	1.9	c_cvertex = (C_VERTEX *)lp->data;
398	gregl	1.25	c_cvertex->clock = 0;
399			c_cvertex->client_data = NULL;
400	greg	1.1	}
401	greg	1.10	i = c_cvertex->clock;
402	greg	1.1	if (ac == 3) { /* use default template */
403			*c_cvertex = c_dfvertex;
404	greg	1.9	c_cvertex->clock = i + 1;
405	greg	1.1	return(MG_OK);
406			}
407			lp = lu_find(&vtx_tab, av[3]); /* lookup template */
408			if (lp == NULL)
409			return(MG_EMEM);
410			if (lp->data == NULL)
411			return(MG_EUNDEF);
412			c_cvertex = (C_VERTEX *)lp->data;
413	greg	1.9	c_cvertex->clock = i + 1;
414	greg	1.1	return(MG_OK);
415			case MG_E_POINT: /* set point */
416			if (ac != 4)
417			return(MG_EARGC);
418	greg	1.18	if (!isflt(av[1]) \| !isflt(av[2]) \| !isflt(av[3]))
419	greg	1.1	return(MG_ETYPE);
420			c_cvertex->p[0] = atof(av[1]);
421			c_cvertex->p[1] = atof(av[2]);
422			c_cvertex->p[2] = atof(av[3]);
423	greg	1.8	c_cvertex->clock++;
424	greg	1.1	return(MG_OK);
425			case MG_E_NORMAL: /* set normal */
426			if (ac != 4)
427			return(MG_EARGC);
428	greg	1.18	if (!isflt(av[1]) \| !isflt(av[2]) \| !isflt(av[3]))
429	greg	1.1	return(MG_ETYPE);
430			c_cvertex->n[0] = atof(av[1]);
431			c_cvertex->n[1] = atof(av[2]);
432			c_cvertex->n[2] = atof(av[3]);
433			(void)normalize(c_cvertex->n);
434	greg	1.8	c_cvertex->clock++;
435	greg	1.1	return(MG_OK);
436			}
437			return(MG_EUNK);
438			}
439
440
441			void
442			c_clearall() /* empty context tables */
443			{
444			c_uncolor = c_dfcolor;
445			c_ccolor = &c_uncolor;
446	greg	1.15	c_ccname = NULL;
447	greg	1.3	lu_done(&clr_tab);
448	greg	1.1	c_unmaterial = c_dfmaterial;
449			c_cmaterial = &c_unmaterial;
450	greg	1.15	c_cmname = NULL;
451	greg	1.3	lu_done(&mat_tab);
452	greg	1.1	c_unvertex = c_dfvertex;
453			c_cvertex = &c_unvertex;
454	greg	1.15	c_cvname = NULL;
455	greg	1.3	lu_done(&vtx_tab);
456	greg	1.1	}
457
458
459	greg	1.11	C_MATERIAL *
460			c_getmaterial(name) /* get a named material */
461			char *name;
462			{
463			register LUENT *lp;
464
465			if ((lp = lu_find(&mat_tab, name)) == NULL)
466			return(NULL);
467			return((C_MATERIAL *)lp->data);
468			}
469
470
471	greg	1.1	C_VERTEX *
472			c_getvert(name) /* get a named vertex */
473			char *name;
474			{
475			register LUENT *lp;
476
477			if ((lp = lu_find(&vtx_tab, name)) == NULL)
478			return(NULL);
479			return((C_VERTEX *)lp->data);
480	greg	1.5	}
481
482
483	greg	1.7	C_COLOR *
484			c_getcolor(name) /* get a named color */
485			char *name;
486			{
487			register LUENT *lp;
488
489			if ((lp = lu_find(&clr_tab, name)) == NULL)
490			return(NULL);
491			return((C_COLOR *)lp->data);
492			}
493
494
495	greg	1.5	int
496			c_isgrey(clr) /* check if color is grey */
497			register C_COLOR *clr;
498			{
499	greg	1.8	if (!(clr->flags & (C_CSXY\|C_CSSPEC)))
500	greg	1.5	return(1); /* no settings == grey */
501			c_ccvt(clr, C_CSXY);
502			return(clr->cx >= .323 && clr->cx <= .343 &&
503			clr->cy >= .323 && clr->cy <= .343);
504			}
505
506
507			void
508			c_ccvt(clr, fl) /* convert color representations */
509			register C_COLOR *clr;
510			int fl;
511			{
512			double x, y, z;
513			register int i;
514
515	greg	1.16	fl &= ~clr->flags; /* ignore what's done */
516			if (!fl) /* everything's done! */
517	greg	1.5	return;
518	greg	1.8	if (!(clr->flags & (C_CSXY\|C_CSSPEC))) /* nothing set! */
519	greg	1.5	*clr = c_dfcolor;
520	greg	1.16	if (fl & C_CSXY) { /* cspec -> cxy */
521	greg	1.5	x = y = z = 0.;
522			for (i = 0; i < C_CNSS; i++) {
523			x += cie_xf.ssamp[i] * clr->ssamp[i];
524			y += cie_yf.ssamp[i] * clr->ssamp[i];
525			z += cie_zf.ssamp[i] * clr->ssamp[i];
526			}
527	greg	1.17	x /= (double)cie_xf.ssum;
528			y /= (double)cie_yf.ssum;
529			z /= (double)cie_zf.ssum;
530	greg	1.5	z += x + y;
531			clr->cx = x / z;
532			clr->cy = y / z;
533			clr->flags \|= C_CSXY;
534	greg	1.16	} else if (fl & C_CSSPEC) { /* cxy -> cspec */
535	greg	1.19	x = clr->cx;
536			y = clr->cy;
537			z = 1. - x - y;
538	greg	1.5	clr->ssum = 0;
539	greg	1.19	for (i = 0; i < C_CNSS; i++) {
540			clr->ssamp[i] = xcie_xp.ssamp[i] + ycie_yp.ssamp[i]
541			+ z*cie_zp.ssamp[i] + .5;
542			if (clr->ssamp[i] < 0) /* out of gamut! */
543			clr->ssamp[i] = 0;
544			else
545			clr->ssum += clr->ssamp[i];
546			}
547	greg	1.5	clr->flags \|= C_CSSPEC;
548			}
549	greg	1.16	if (fl & C_CSEFF) { /* compute efficacy */
550	greg	1.19	if (clr->flags & C_CSSPEC) { /* from spectrum */
551	greg	1.16	y = 0.;
552			for (i = 0; i < C_CNSS; i++)
553			y += cie_yf.ssamp[i] * clr->ssamp[i];
554			clr->eff = C_CLPWM * y / clr->ssum;
555	greg	1.19	} else /* clr->flags & C_CSXY / { / from (x,y) */
556	greg	1.16	clr->eff = clr->cxcie_xf.eff + clr->cycie_yf.eff +
557			(1. - clr->cx - clr->cy)*cie_zf.eff;
558			}
559			clr->flags \|= C_CSEFF;
560			}
561	greg	1.5	}
562
563
564			static int
565			setspectrum(clr, wlmin, wlmax, ac, av) /* convert a spectrum */
566			register C_COLOR *clr;
567	greg	1.17	double wlmin, wlmax;
568	greg	1.5	int ac;
569			char **av;
570			{
571			double scale;
572	greg	1.17	float va[C_CNSS];
573			register int i, pos;
574			int n, imax;
575			int wl;
576	greg	1.5	double wl0, wlstep;
577	greg	1.20	double boxpos, boxstep;
578	greg	1.17	/* check bounds */
579			if (wlmax <= C_CMINWL \| wlmax <= wlmin \| wlmin >= C_CMAXWL)
580	greg	1.5	return(MG_EILL);
581	greg	1.17	wlstep = (wlmax - wlmin)/(ac-1);
582			while (wlmin < C_CMINWL) {
583			wlmin += wlstep;
584			ac--; av++;
585			}
586			while (wlmax > C_CMAXWL) {
587			wlmax -= wlstep;
588			ac--;
589			}
590			imax = ac; /* box filter if necessary */
591	greg	1.20	boxpos = 0;
592			boxstep = 1;
593	greg	1.17	if (wlstep < C_CWLI) {
594	greg	1.20	imax = (wlmax - wlmin)/C_CWLI + (1-FTINY);
595			boxpos = (wlmin - C_CMINWL)/C_CWLI;
596			boxstep = wlstep/C_CWLI;
597	greg	1.17	wlstep = C_CWLI;
598			}
599	greg	1.5	scale = 0.; /* get values and maximum */
600	greg	1.17	pos = 0;
601			for (i = 0; i < imax; i++) {
602			va[i] = 0.; n = 0;
603	greg	1.20	while (boxpos < i+.5 && pos < ac) {
604	greg	1.17	if (!isflt(av[pos]))
605			return(MG_ETYPE);
606			va[i] += atof(av[pos++]);
607			n++;
608	greg	1.20	boxpos += boxstep;
609	greg	1.17	}
610			if (n > 1)
611			va[i] /= (double)n;
612	greg	1.5	if (va[i] > scale)
613			scale = va[i];
614	greg	1.23	else if (va[i] < -scale)
615			scale = -va[i];
616	greg	1.5	}
617	greg	1.20	if (scale <= FTINY)
618	greg	1.5	return(MG_EILL);
619			scale = C_CMAXV / scale;
620			clr->ssum = 0; /* convert to our spacing */
621			wl0 = wlmin;
622			pos = 0;
623			for (i = 0, wl = C_CMINWL; i < C_CNSS; i++, wl += C_CWLI)
624	greg	1.17	if (wl < wlmin \| wl > wlmax)
625	greg	1.5	clr->ssamp[i] = 0;
626			else {
627			while (wl0 + wlstep < wl+FTINY) {
628			wl0 += wlstep;
629			pos++;
630			}
631	greg	1.17	if (wl+FTINY >= wl0 & wl-FTINY <= wl0)
632	greg	1.18	clr->ssamp[i] = scale*va[pos] + .5;
633	greg	1.5	else /* interpolate if necessary */
634	greg	1.18	clr->ssamp[i] = .5 + scale / wlstep *
635	greg	1.5	( va[pos]*(wl0+wlstep - wl) +
636			va[pos+1]*(wl - wl0) );
637			clr->ssum += clr->ssamp[i];
638			}
639			clr->flags = C_CDSPEC\|C_CSSPEC;
640	greg	1.8	clr->clock++;
641	greg	1.5	return(MG_OK);
642			}
643
644
645			static void
646			mixcolors(cres, w1, c1, w2, c2) /* mix two colors according to weights given */
647			register C_COLOR cres, c1, *c2;
648			double w1, w2;
649			{
650			double scale;
651			float cmix[C_CNSS];
652			register int i;
653
654			if ((c1->flags\|c2->flags) & C_CDSPEC) { /* spectral mixing */
655	greg	1.16	c_ccvt(c1, C_CSSPEC\|C_CSEFF);
656			c_ccvt(c2, C_CSSPEC\|C_CSEFF);
657			w1 /= c1->eff*c1->ssum;
658	greg	1.17	w2 /= c2->eff*c2->ssum;
659	greg	1.5	scale = 0.;
660			for (i = 0; i < C_CNSS; i++) {
661			cmix[i] = w1c1->ssamp[i] + w2c2->ssamp[i];
662			if (cmix[i] > scale)
663			scale = cmix[i];
664			}
665			scale = C_CMAXV / scale;
666			cres->ssum = 0;
667			for (i = 0; i < C_CNSS; i++)
668			cres->ssum += cres->ssamp[i] = scale*cmix[i] + .5;
669			cres->flags = C_CDSPEC\|C_CSSPEC;
670			} else { /* CIE xy mixing */
671			c_ccvt(c1, C_CSXY);
672			c_ccvt(c2, C_CSXY);
673	greg	1.24	scale = w1/c1->cy + w2/c2->cy;
674			if (scale == 0.)
675			return;
676			scale = 1. / scale;
677	greg	1.5	cres->cx = (c1->cxw1/c1->cy + c2->cxw2/c2->cy) * scale;
678			cres->cy = (w1 + w2) * scale;
679			cres->flags = C_CDXY\|C_CSXY;
680			}
681	greg	1.1	}
682	greg	1.18
683
684			#define C1 3.741832e-16 /* W-m^2 */
685			#define C2 1.4388e-2 /* m-K */
686
687			#define bbsp(l,t) (C1/((l)(l)(l)(l)(l)(exp(C2/((t)(l)))-1.)))
688			#define bblm(t) (C2/5./(t))
689
690			static int
691			setbbtemp(clr, tk) /* set black body spectrum */
692			register C_COLOR *clr;
693			double tk;
694			{
695			double sf, wl;
696			register int i;
697
698			if (tk < 1000)
699			return(MG_EILL);
700			wl = bblm(tk); /* scalefactor based on peak */
701			if (wl < C_CMINWL*1e-9)
702			wl = C_CMINWL*1e-9;
703			else if (wl > C_CMAXWL*1e-9)
704			wl = C_CMAXWL*1e-9;
705			sf = C_CMAXV/bbsp(wl,tk);
706			clr->ssum = 0;
707			for (i = 0; i < C_CNSS; i++) {
708			wl = (C_CMINWL + iC_CWLI)1e-9;
709			clr->ssum += clr->ssamp[i] = sf*bbsp(wl,tk) + .5;
710			}
711			clr->flags = C_CDSPEC\|C_CSSPEC;
712			clr->clock++;
713			return(MG_OK);
714			}
715
716			#undef C1
717			#undef C2
718			#undef bbsp
719			#undef bblm