cv/mgflib/context.c

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

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

/*
 * Context handlers
 */

#include <stdio.h>
#include <math.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 */
static C_COLOR  cie_xf = C_CIEX;
static C_COLOR  cie_yf = C_CIEY;
static C_COLOR  cie_zf = C_CIEZ;

static int      setspectrum();
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);
                }
                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;
                }
                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 (!isint(av[1]) || !isint(av[2]))
                        return(MG_ETYPE);
                return(setspectrum(c_ccolor, atoi(av[1]), atoi(av[2]),
                                ac-3, av+3));
        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 (wsum < 0.)
                        return(MG_EILL);
                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 (w < 0.)
                                return(MG_EILL);
                        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;
                }
                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);
                }
                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;
                }
                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_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);
                }
                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;
                }
                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];
                }
                z += x + y;
                clr->cx = x / z;
                clr->cy = y / z;
                clr->flags |= C_CSXY;
        } else if (fl & C_CSSPEC) {     /* cxy -> cspec */
                z = (cie_xf.ssum + cie_yf.ssum + cie_zf.ssum) / 3.;
                x = clr->cx * z / cie_xf.ssum;
                y = clr->cy * z / cie_yf.ssum;
                z = (1. - clr->cx - clr->cy) * z / cie_zf.ssum;
                clr->ssum = 0;
                for (i = 0; i < C_CNSS; i++)
                        clr->ssum += clr->ssamp[i] =
                                        x * cie_xf.ssamp[i] +
                                        y * cie_yf.ssamp[i] +
                                        z * cie_zf.ssamp[i] ;
                clr->flags |= C_CSSPEC;
        }
        if (fl & C_CSEFF) {             /* compute efficacy */
                if (clr->flags & C_CDSPEC) {            /* 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_CDXY */ {      /* 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;
int     wlmin, wlmax;
int     ac;
char    **av;
{
        double  scale;
        float   *va;
        register int    i;
        int     wl, pos;
        double  wl0, wlstep;

        if (wlmin < C_CMINWL || wlmin >= wlmax || wlmax > C_CMAXWL)
                return(MG_EILL);
        if ((va = (float *)malloc(ac*sizeof(float))) == NULL)
                return(MG_EMEM);
        scale = 0.;                     /* get values and maximum */
        for (i = 0; i < ac; i++) {
                if (!isflt(av[i]))
                        return(MG_ETYPE);
                va[i] = atof(av[i]);
                if (va[i] < 0.)
                        return(MG_EILL);
                if (va[i] > scale)
                        scale = va[i];
        }
        if (scale == 0.)
                return(MG_EILL);
        scale = C_CMAXV / scale;
        clr->ssum = 0;                  /* convert to our spacing */
        wl0 = wlmin;
        wlstep = (double)(wlmax - wlmin)/(ac-1);
        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];
                        else            /* interpolate if necessary */
                                clr->ssamp[i] = 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++;
        free((MEM_PTR)va);
        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 /= c1->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 = 1. / (w1/c1->cy + w2/c2->cy);
                cres->cx = (c1->cx*w1/c1->cy + c2->cx*w2/c2->cy) * scale;
                cres->cy = (w1 + w2) * scale;
                cres->flags = C_CDXY|C_CSXY;
        }
}
Revision:	1.16
Committed:	Fri Sep 2 16:04:19 1994 UTC (31 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.15:	+20 -7 lines
Log Message:	corrected problems with cmix function (I think -- needs checking!)
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1994 Regents of the University of California */
2
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	greg	1.1	#include <string.h>
14			#include "parser.h"
15			#include "lookup.h"
16
17			/* default context values */
18			static C_COLOR c_dfcolor = C_DEFCOLOR;
19			static C_MATERIAL c_dfmaterial = C_DEFMATERIAL;
20			static C_VERTEX c_dfvertex = C_DEFVERTEX;
21
22			/* the unnamed contexts */
23			static C_COLOR c_uncolor = C_DEFCOLOR;
24			static C_MATERIAL c_unmaterial = C_DEFMATERIAL;
25			static C_VERTEX c_unvertex = C_DEFVERTEX;
26
27			/* the current contexts */
28			C_COLOR *c_ccolor = &c_uncolor;
29	greg	1.12	char *c_ccname = NULL;
30	greg	1.1	C_MATERIAL *c_cmaterial = &c_unmaterial;
31	greg	1.12	char *c_cmname = NULL;
32	greg	1.1	C_VERTEX *c_cvertex = &c_unvertex;
33	greg	1.12	char *c_cvname = NULL;
34	greg	1.1
35	greg	1.3	static LUTAB clr_tab = LU_SINIT(free,free); /* color lookup table */
36			static LUTAB mat_tab = LU_SINIT(free,free); /* material lookup table */
37			static LUTAB vtx_tab = LU_SINIT(free,free); /* vertex lookup table */
38	greg	1.1
39	greg	1.5	/* CIE 1931 Standard Observer */
40			static C_COLOR cie_xf = C_CIEX;
41			static C_COLOR cie_yf = C_CIEY;
42			static C_COLOR cie_zf = C_CIEZ;
43	greg	1.1
44	greg	1.5	static int setspectrum();
45			static void mixcolors();
46
47
48	greg	1.1	int
49			c_hcolor(ac, av) /* handle color entity */
50			int ac;
51			register char **av;
52			{
53	greg	1.5	double w, wsum;
54			register int i;
55	greg	1.1	register LUENT *lp;
56
57			switch (mg_entity(av[0])) {
58			case MG_E_COLOR: /* get/set color context */
59	greg	1.4	if (ac > 4)
60			return(MG_EARGC);
61	greg	1.1	if (ac == 1) { /* set unnamed color context */
62			c_uncolor = c_dfcolor;
63			c_ccolor = &c_uncolor;
64	greg	1.12	c_ccname = NULL;
65	greg	1.1	return(MG_OK);
66			}
67			lp = lu_find(&clr_tab, av[1]); /* lookup context */
68			if (lp == NULL)
69			return(MG_EMEM);
70	greg	1.14	c_ccname = lp->key;
71	greg	1.9	c_ccolor = (C_COLOR *)lp->data;
72	greg	1.1	if (ac == 2) { /* reestablish previous context */
73	greg	1.9	if (c_ccolor == NULL)
74	greg	1.1	return(MG_EUNDEF);
75			return(MG_OK);
76			}
77			if (av[2][0] != '=' \|\| av[2][1])
78			return(MG_ETYPE);
79	greg	1.9	if (c_ccolor == NULL) { /* create new color context */
80	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
81			if (lp->key == NULL)
82			return(MG_EMEM);
83			strcpy(lp->key, av[1]);
84			lp->data = (char *)malloc(sizeof(C_COLOR));
85			if (lp->data == NULL)
86			return(MG_EMEM);
87	greg	1.14	c_ccname = lp->key;
88	greg	1.9	c_ccolor = (C_COLOR *)lp->data;
89			c_ccolor->clock = 0;
90	greg	1.1	}
91	greg	1.10	i = c_ccolor->clock;
92	greg	1.1	if (ac == 3) { /* use default template */
93			*c_ccolor = c_dfcolor;
94	greg	1.9	c_ccolor->clock = i + 1;
95	greg	1.1	return(MG_OK);
96			}
97			lp = lu_find(&clr_tab, av[3]); /* lookup template */
98			if (lp == NULL)
99			return(MG_EMEM);
100			if (lp->data == NULL)
101			return(MG_EUNDEF);
102			c_ccolor = (C_COLOR *)lp->data;
103	greg	1.9	c_ccolor->clock = i + 1;
104	greg	1.1	return(MG_OK);
105			case MG_E_CXY: /* assign CIE XY value */
106			if (ac != 3)
107			return(MG_EARGC);
108			if (!isflt(av[1]) \|\| !isflt(av[2]))
109			return(MG_ETYPE);
110			c_ccolor->cx = atof(av[1]);
111			c_ccolor->cy = atof(av[2]);
112	greg	1.5	c_ccolor->flags = C_CDXY\|C_CSXY;
113	greg	1.1	if (c_ccolor->cx < 0. \| c_ccolor->cy < 0. \|
114			c_ccolor->cx + c_ccolor->cy > 1.)
115			return(MG_EILL);
116	greg	1.8	c_ccolor->clock++;
117	greg	1.1	return(MG_OK);
118	greg	1.5	case MG_E_CSPEC: /* assign spectral values */
119			if (ac < 5)
120			return(MG_EARGC);
121			if (!isint(av[1]) \|\| !isint(av[2]))
122			return(MG_ETYPE);
123			return(setspectrum(c_ccolor, atoi(av[1]), atoi(av[2]),
124			ac-3, av+3));
125			case MG_E_CMIX: /* mix colors */
126			if (ac < 5 \|\| (ac-1)%2)
127			return(MG_EARGC);
128			if (!isflt(av[1]))
129			return(MG_ETYPE);
130			wsum = atof(av[1]);
131			if (wsum < 0.)
132			return(MG_EILL);
133			if ((lp = lu_find(&clr_tab, av[2])) == NULL)
134			return(MG_EMEM);
135			if (lp->data == NULL)
136			return(MG_EUNDEF);
137			c_ccolor = (C_COLOR *)lp->data;
138			for (i = 3; i < ac; i += 2) {
139			if (!isflt(av[i]))
140			return(MG_ETYPE);
141			w = atof(av[i]);
142			if (w < 0.)
143			return(MG_EILL);
144			if ((lp = lu_find(&clr_tab, av[i+1])) == NULL)
145			return(MG_EMEM);
146			if (lp->data == NULL)
147			return(MG_EUNDEF);
148			mixcolors(c_ccolor, wsum, c_ccolor,
149			w, (C_COLOR *)lp->data);
150			wsum += w;
151			}
152	greg	1.10	c_ccolor->clock++;
153	greg	1.5	return(MG_OK);
154	greg	1.1	}
155			return(MG_EUNK);
156			}
157
158
159			int
160			c_hmaterial(ac, av) /* handle material entity */
161			int ac;
162			register char **av;
163			{
164	greg	1.9	int i;
165	greg	1.1	register LUENT *lp;
166
167			switch (mg_entity(av[0])) {
168			case MG_E_MATERIAL: /* get/set material context */
169	greg	1.4	if (ac > 4)
170			return(MG_EARGC);
171	greg	1.1	if (ac == 1) { /* set unnamed material context */
172			c_unmaterial = c_dfmaterial;
173			c_cmaterial = &c_unmaterial;
174	greg	1.12	c_cmname = NULL;
175	greg	1.1	return(MG_OK);
176			}
177			lp = lu_find(&mat_tab, av[1]); /* lookup context */
178			if (lp == NULL)
179			return(MG_EMEM);
180	greg	1.14	c_cmname = lp->key;
181	greg	1.9	c_cmaterial = (C_MATERIAL *)lp->data;
182	greg	1.1	if (ac == 2) { /* reestablish previous context */
183	greg	1.9	if (c_cmaterial == NULL)
184	greg	1.1	return(MG_EUNDEF);
185			return(MG_OK);
186			}
187			if (av[2][0] != '=' \|\| av[2][1])
188			return(MG_ETYPE);
189	greg	1.9	if (c_cmaterial == NULL) { /* create new material */
190	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
191			if (lp->key == NULL)
192			return(MG_EMEM);
193			strcpy(lp->key, av[1]);
194			lp->data = (char *)malloc(sizeof(C_MATERIAL));
195			if (lp->data == NULL)
196			return(MG_EMEM);
197	greg	1.14	c_cmname = lp->key;
198	greg	1.9	c_cmaterial = (C_MATERIAL *)lp->data;
199			c_cmaterial->clock = 0;
200	greg	1.1	}
201	greg	1.10	i = c_cmaterial->clock;
202	greg	1.1	if (ac == 3) { /* use default template */
203			*c_cmaterial = c_dfmaterial;
204	greg	1.9	c_cmaterial->clock = i + 1;
205	greg	1.1	return(MG_OK);
206			}
207			lp = lu_find(&mat_tab, av[3]); /* lookup template */
208			if (lp == NULL)
209			return(MG_EMEM);
210			if (lp->data == NULL)
211			return(MG_EUNDEF);
212			c_cmaterial = (C_MATERIAL *)lp->data;
213	greg	1.9	c_cmaterial->clock = i + 1;
214	greg	1.1	return(MG_OK);
215			case MG_E_RD: /* set diffuse reflectance */
216			if (ac != 2)
217			return(MG_EARGC);
218			if (!isflt(av[1]))
219			return(MG_ETYPE);
220			c_cmaterial->rd = atof(av[1]);
221			if (c_cmaterial->rd < 0. \| c_cmaterial->rd > 1.)
222			return(MG_EILL);
223			c_cmaterial->rd_c = *c_ccolor;
224	greg	1.2	c_cmaterial->clock++;
225	greg	1.1	return(MG_OK);
226			case MG_E_ED: /* set diffuse emittance */
227			if (ac != 2)
228			return(MG_EARGC);
229			if (!isflt(av[1]))
230			return(MG_ETYPE);
231			c_cmaterial->ed = atof(av[1]);
232			if (c_cmaterial->ed < 0.)
233			return(MG_EILL);
234			c_cmaterial->ed_c = *c_ccolor;
235	greg	1.2	c_cmaterial->clock++;
236	greg	1.1	return(MG_OK);
237			case MG_E_TD: /* set diffuse transmittance */
238			if (ac != 2)
239			return(MG_EARGC);
240			if (!isflt(av[1]))
241			return(MG_ETYPE);
242			c_cmaterial->td = atof(av[1]);
243			if (c_cmaterial->td < 0. \| c_cmaterial->td > 1.)
244			return(MG_EILL);
245			c_cmaterial->td_c = *c_ccolor;
246	greg	1.8	c_cmaterial->clock++;
247	greg	1.1	return(MG_OK);
248			case MG_E_RS: /* set specular reflectance */
249			if (ac != 3)
250			return(MG_EARGC);
251			if (!isflt(av[1]) \|\| !isflt(av[2]))
252			return(MG_ETYPE);
253			c_cmaterial->rs = atof(av[1]);
254			c_cmaterial->rs_a = atof(av[2]);
255			if (c_cmaterial->rs < 0. \| c_cmaterial->rs > 1. \|
256			c_cmaterial->rs_a < 0.)
257			return(MG_EILL);
258			c_cmaterial->rs_c = *c_ccolor;
259	greg	1.2	c_cmaterial->clock++;
260	greg	1.1	return(MG_OK);
261			case MG_E_TS: /* set specular transmittance */
262			if (ac != 3)
263			return(MG_EARGC);
264			if (!isflt(av[1]) \|\| !isflt(av[2]))
265			return(MG_ETYPE);
266			c_cmaterial->ts = atof(av[1]);
267			c_cmaterial->ts_a = atof(av[2]);
268			if (c_cmaterial->ts < 0. \| c_cmaterial->ts > 1. \|
269			c_cmaterial->ts_a < 0.)
270			return(MG_EILL);
271			c_cmaterial->ts_c = *c_ccolor;
272	greg	1.2	c_cmaterial->clock++;
273	greg	1.1	return(MG_OK);
274	greg	1.13	case MG_E_SIDES: /* set number of sides */
275			if (ac != 2)
276			return(MG_EARGC);
277			if (!isint(av[1]))
278			return(MG_ETYPE);
279			i = atoi(av[1]);
280			if (i == 1)
281			c_cmaterial->sided = 1;
282			else if (i == 2)
283			c_cmaterial->sided = 0;
284			else
285			return(MG_EILL);
286			c_cmaterial->clock++;
287			return(MG_OK);
288	greg	1.1	}
289			return(MG_EUNK);
290			}
291
292
293			int
294			c_hvertex(ac, av) /* handle a vertex entity */
295			int ac;
296			register char **av;
297			{
298	greg	1.9	int i;
299	greg	1.1	register LUENT *lp;
300
301			switch (mg_entity(av[0])) {
302			case MG_E_VERTEX: /* get/set vertex context */
303	greg	1.4	if (ac > 4)
304			return(MG_EARGC);
305	greg	1.1	if (ac == 1) { /* set unnamed vertex context */
306			c_unvertex = c_dfvertex;
307			c_cvertex = &c_unvertex;
308	greg	1.12	c_cvname = NULL;
309	greg	1.1	return(MG_OK);
310			}
311			lp = lu_find(&vtx_tab, av[1]); /* lookup context */
312			if (lp == NULL)
313			return(MG_EMEM);
314	greg	1.14	c_cvname = lp->key;
315	greg	1.9	c_cvertex = (C_VERTEX *)lp->data;
316	greg	1.1	if (ac == 2) { /* reestablish previous context */
317	greg	1.9	if (c_cvertex == NULL)
318	greg	1.1	return(MG_EUNDEF);
319			return(MG_OK);
320			}
321			if (av[2][0] != '=' \|\| av[2][1])
322			return(MG_ETYPE);
323	greg	1.9	if (c_cvertex == NULL) { /* create new vertex context */
324	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
325			if (lp->key == NULL)
326			return(MG_EMEM);
327			strcpy(lp->key, av[1]);
328			lp->data = (char *)malloc(sizeof(C_VERTEX));
329			if (lp->data == NULL)
330			return(MG_EMEM);
331	greg	1.14	c_cvname = lp->key;
332	greg	1.9	c_cvertex = (C_VERTEX *)lp->data;
333	greg	1.1	}
334	greg	1.10	i = c_cvertex->clock;
335	greg	1.1	if (ac == 3) { /* use default template */
336			*c_cvertex = c_dfvertex;
337	greg	1.9	c_cvertex->clock = i + 1;
338	greg	1.1	return(MG_OK);
339			}
340			lp = lu_find(&vtx_tab, av[3]); /* lookup template */
341			if (lp == NULL)
342			return(MG_EMEM);
343			if (lp->data == NULL)
344			return(MG_EUNDEF);
345			c_cvertex = (C_VERTEX *)lp->data;
346	greg	1.9	c_cvertex->clock = i + 1;
347	greg	1.1	return(MG_OK);
348			case MG_E_POINT: /* set point */
349			if (ac != 4)
350			return(MG_EARGC);
351			if (!isflt(av[1]) \|\| !isflt(av[2]) \|\| !isflt(av[3]))
352			return(MG_ETYPE);
353			c_cvertex->p[0] = atof(av[1]);
354			c_cvertex->p[1] = atof(av[2]);
355			c_cvertex->p[2] = atof(av[3]);
356	greg	1.8	c_cvertex->clock++;
357	greg	1.1	return(MG_OK);
358			case MG_E_NORMAL: /* set normal */
359			if (ac != 4)
360			return(MG_EARGC);
361			if (!isflt(av[1]) \|\| !isflt(av[2]) \|\| !isflt(av[3]))
362			return(MG_ETYPE);
363			c_cvertex->n[0] = atof(av[1]);
364			c_cvertex->n[1] = atof(av[2]);
365			c_cvertex->n[2] = atof(av[3]);
366			(void)normalize(c_cvertex->n);
367	greg	1.8	c_cvertex->clock++;
368	greg	1.1	return(MG_OK);
369			}
370			return(MG_EUNK);
371			}
372
373
374			void
375			c_clearall() /* empty context tables */
376			{
377			c_uncolor = c_dfcolor;
378			c_ccolor = &c_uncolor;
379	greg	1.15	c_ccname = NULL;
380	greg	1.3	lu_done(&clr_tab);
381	greg	1.1	c_unmaterial = c_dfmaterial;
382			c_cmaterial = &c_unmaterial;
383	greg	1.15	c_cmname = NULL;
384	greg	1.3	lu_done(&mat_tab);
385	greg	1.1	c_unvertex = c_dfvertex;
386			c_cvertex = &c_unvertex;
387	greg	1.15	c_cvname = NULL;
388	greg	1.3	lu_done(&vtx_tab);
389	greg	1.1	}
390
391
392	greg	1.11	C_MATERIAL *
393			c_getmaterial(name) /* get a named material */
394			char *name;
395			{
396			register LUENT *lp;
397
398			if ((lp = lu_find(&mat_tab, name)) == NULL)
399			return(NULL);
400			return((C_MATERIAL *)lp->data);
401			}
402
403
404	greg	1.1	C_VERTEX *
405			c_getvert(name) /* get a named vertex */
406			char *name;
407			{
408			register LUENT *lp;
409
410			if ((lp = lu_find(&vtx_tab, name)) == NULL)
411			return(NULL);
412			return((C_VERTEX *)lp->data);
413	greg	1.5	}
414
415
416	greg	1.7	C_COLOR *
417			c_getcolor(name) /* get a named color */
418			char *name;
419			{
420			register LUENT *lp;
421
422			if ((lp = lu_find(&clr_tab, name)) == NULL)
423			return(NULL);
424			return((C_COLOR *)lp->data);
425			}
426
427
428	greg	1.5	int
429			c_isgrey(clr) /* check if color is grey */
430			register C_COLOR *clr;
431			{
432	greg	1.8	if (!(clr->flags & (C_CSXY\|C_CSSPEC)))
433	greg	1.5	return(1); /* no settings == grey */
434			c_ccvt(clr, C_CSXY);
435			return(clr->cx >= .323 && clr->cx <= .343 &&
436			clr->cy >= .323 && clr->cy <= .343);
437			}
438
439
440			void
441			c_ccvt(clr, fl) /* convert color representations */
442			register C_COLOR *clr;
443			int fl;
444			{
445			double x, y, z;
446			register int i;
447
448	greg	1.16	fl &= ~clr->flags; /* ignore what's done */
449			if (!fl) /* everything's done! */
450	greg	1.5	return;
451	greg	1.8	if (!(clr->flags & (C_CSXY\|C_CSSPEC))) /* nothing set! */
452	greg	1.5	*clr = c_dfcolor;
453	greg	1.16	if (fl & C_CSXY) { /* cspec -> cxy */
454	greg	1.5	x = y = z = 0.;
455			for (i = 0; i < C_CNSS; i++) {
456			x += cie_xf.ssamp[i] * clr->ssamp[i];
457			y += cie_yf.ssamp[i] * clr->ssamp[i];
458			z += cie_zf.ssamp[i] * clr->ssamp[i];
459			}
460			z += x + y;
461			clr->cx = x / z;
462			clr->cy = y / z;
463			clr->flags \|= C_CSXY;
464	greg	1.16	} else if (fl & C_CSSPEC) { /* cxy -> cspec */
465	greg	1.5	z = (cie_xf.ssum + cie_yf.ssum + cie_zf.ssum) / 3.;
466			x = clr->cx * z / cie_xf.ssum;
467			y = clr->cy * z / cie_yf.ssum;
468			z = (1. - clr->cx - clr->cy) * z / cie_zf.ssum;
469			clr->ssum = 0;
470			for (i = 0; i < C_CNSS; i++)
471			clr->ssum += clr->ssamp[i] =
472			x * cie_xf.ssamp[i] +
473			y * cie_yf.ssamp[i] +
474			z * cie_zf.ssamp[i] ;
475			clr->flags \|= C_CSSPEC;
476			}
477	greg	1.16	if (fl & C_CSEFF) { /* compute efficacy */
478			if (clr->flags & C_CDSPEC) { /* from spectrum */
479			y = 0.;
480			for (i = 0; i < C_CNSS; i++)
481			y += cie_yf.ssamp[i] * clr->ssamp[i];
482			clr->eff = C_CLPWM * y / clr->ssum;
483			} else /* clr->flags & C_CDXY / { / from (x,y) */
484			clr->eff = clr->cxcie_xf.eff + clr->cycie_yf.eff +
485			(1. - clr->cx - clr->cy)*cie_zf.eff;
486			}
487			clr->flags \|= C_CSEFF;
488			}
489	greg	1.5	}
490
491
492			static int
493			setspectrum(clr, wlmin, wlmax, ac, av) /* convert a spectrum */
494			register C_COLOR *clr;
495			int wlmin, wlmax;
496			int ac;
497			char **av;
498			{
499			double scale;
500			float *va;
501			register int i;
502			int wl, pos;
503			double wl0, wlstep;
504
505			if (wlmin < C_CMINWL \|\| wlmin >= wlmax \|\| wlmax > C_CMAXWL)
506			return(MG_EILL);
507			if ((va = (float )malloc(acsizeof(float))) == NULL)
508			return(MG_EMEM);
509			scale = 0.; /* get values and maximum */
510			for (i = 0; i < ac; i++) {
511			if (!isflt(av[i]))
512			return(MG_ETYPE);
513			va[i] = atof(av[i]);
514			if (va[i] < 0.)
515			return(MG_EILL);
516			if (va[i] > scale)
517			scale = va[i];
518			}
519			if (scale == 0.)
520			return(MG_EILL);
521			scale = C_CMAXV / scale;
522			clr->ssum = 0; /* convert to our spacing */
523			wl0 = wlmin;
524			wlstep = (double)(wlmax - wlmin)/(ac-1);
525			pos = 0;
526			for (i = 0, wl = C_CMINWL; i < C_CNSS; i++, wl += C_CWLI)
527			if (wl < wlmin \|\| wl > wlmax)
528			clr->ssamp[i] = 0;
529			else {
530			while (wl0 + wlstep < wl+FTINY) {
531			wl0 += wlstep;
532			pos++;
533			}
534			if (wl+FTINY >= wl0 && wl-FTINY <= wl0)
535			clr->ssamp[i] = scale*va[pos];
536			else /* interpolate if necessary */
537			clr->ssamp[i] = scale / wlstep *
538			( va[pos]*(wl0+wlstep - wl) +
539			va[pos+1]*(wl - wl0) );
540			clr->ssum += clr->ssamp[i];
541			}
542			clr->flags = C_CDSPEC\|C_CSSPEC;
543	greg	1.8	clr->clock++;
544	greg	1.5	free((MEM_PTR)va);
545			return(MG_OK);
546			}
547
548
549			static void
550			mixcolors(cres, w1, c1, w2, c2) /* mix two colors according to weights given */
551			register C_COLOR cres, c1, *c2;
552			double w1, w2;
553			{
554			double scale;
555			float cmix[C_CNSS];
556			register int i;
557
558			if ((c1->flags\|c2->flags) & C_CDSPEC) { /* spectral mixing */
559	greg	1.16	c_ccvt(c1, C_CSSPEC\|C_CSEFF);
560			c_ccvt(c2, C_CSSPEC\|C_CSEFF);
561			w1 /= c1->eff*c1->ssum;
562			w2 /= c1->eff*c2->ssum;
563	greg	1.5	scale = 0.;
564			for (i = 0; i < C_CNSS; i++) {
565			cmix[i] = w1c1->ssamp[i] + w2c2->ssamp[i];
566			if (cmix[i] > scale)
567			scale = cmix[i];
568			}
569			scale = C_CMAXV / scale;
570			cres->ssum = 0;
571			for (i = 0; i < C_CNSS; i++)
572			cres->ssum += cres->ssamp[i] = scale*cmix[i] + .5;
573			cres->flags = C_CDSPEC\|C_CSSPEC;
574			} else { /* CIE xy mixing */
575			c_ccvt(c1, C_CSXY);
576			c_ccvt(c2, C_CSXY);
577			scale = 1. / (w1/c1->cy + w2/c2->cy);
578			cres->cx = (c1->cxw1/c1->cy + c2->cxw2/c2->cy) * scale;
579			cres->cy = (w1 + w2) * scale;
580			cres->flags = C_CDXY\|C_CSXY;
581			}
582	greg	1.1	}