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;
C_MATERIAL      *c_cmaterial = &c_unmaterial;
C_VERTEX        *c_cvertex = &c_unvertex;

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;
                        return(MG_OK);
                }
                lp = lu_find(&clr_tab, av[1]);  /* lookup context */
                if (lp == NULL)
                        return(MG_EMEM);
                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_ccolor = (C_COLOR *)lp->data;
                        c_ccolor->clock = 0;
                }
                if (ac == 3) {          /* use default template */
                        i = c_ccolor->clock;
                        *c_ccolor = c_dfcolor;
                        c_ccolor->name = av[1];
                        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);
                i = c_ccolor->clock;
                *c_ccolor = *(C_COLOR *)lp->data;
                c_ccolor->name = av[1];
                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;
                }
                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;
                        return(MG_OK);
                }
                lp = lu_find(&mat_tab, av[1]);  /* lookup context */
                if (lp == NULL)
                        return(MG_EMEM);
                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_cmaterial = (C_MATERIAL *)lp->data;
                        c_cmaterial->clock = 0;
                }
                if (ac == 3) {          /* use default template */
                        i = c_cmaterial->clock;
                        *c_cmaterial = c_dfmaterial;
                        c_cmaterial->name = av[1];
                        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);
                i = c_cmaterial->clock;
                *c_cmaterial = *(C_MATERIAL *)lp->data;
                c_cmaterial->name = av[1];
                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);
        }
        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;
                        return(MG_OK);
                }
                lp = lu_find(&vtx_tab, av[1]);  /* lookup context */
                if (lp == NULL)
                        return(MG_EMEM);
                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_cvertex = (C_VERTEX *)lp->data;
                }
                if (ac == 3) {          /* use default template */
                        i = c_cvertex->clock;
                        *c_cvertex = c_dfvertex;
                        c_cvertex->name = av[1];
                        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);
                i = c_cvertex->clock;
                *c_cvertex = *(C_VERTEX *)lp->data;
                c_cvertex->name = av[1];
                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;
        lu_done(&clr_tab);
        c_unmaterial = c_dfmaterial;
        c_cmaterial = &c_unmaterial;
        lu_done(&mat_tab);
        c_unvertex = c_dfvertex;
        c_cvertex = &c_unvertex;
        lu_done(&vtx_tab);
}


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;

        if (clr->flags & fl)            /* already done */
                return;
        if (!(clr->flags & (C_CSXY|C_CSSPEC)))  /* nothing set! */
                *clr = c_dfcolor;
        else 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 {                        /* 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;
        }
}


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_ccvt(c2, C_CSSPEC);
                w1 /= (double)c1->ssum;
                w2 /= (double)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;
        }
        cres->clock++;                  /* record the change */
}
Revision:	1.9
Committed:	Sat Jun 25 16:33:14 1994 UTC (29 years, 10 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.8:	+34 -27 lines
Log Message:	bug fixes and enhancements
#	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			C_MATERIAL *c_cmaterial = &c_unmaterial;
30			C_VERTEX *c_cvertex = &c_unvertex;
31
32	greg	1.3	static LUTAB clr_tab = LU_SINIT(free,free); /* color lookup table */
33			static LUTAB mat_tab = LU_SINIT(free,free); /* material lookup table */
34			static LUTAB vtx_tab = LU_SINIT(free,free); /* vertex lookup table */
35	greg	1.1
36	greg	1.5	/* CIE 1931 Standard Observer */
37			static C_COLOR cie_xf = C_CIEX;
38			static C_COLOR cie_yf = C_CIEY;
39			static C_COLOR cie_zf = C_CIEZ;
40	greg	1.1
41	greg	1.5	static int setspectrum();
42			static void mixcolors();
43
44
45	greg	1.1	int
46			c_hcolor(ac, av) /* handle color entity */
47			int ac;
48			register char **av;
49			{
50	greg	1.5	double w, wsum;
51			register int i;
52	greg	1.1	register LUENT *lp;
53
54			switch (mg_entity(av[0])) {
55			case MG_E_COLOR: /* get/set color context */
56	greg	1.4	if (ac > 4)
57			return(MG_EARGC);
58	greg	1.1	if (ac == 1) { /* set unnamed color context */
59			c_uncolor = c_dfcolor;
60			c_ccolor = &c_uncolor;
61			return(MG_OK);
62			}
63			lp = lu_find(&clr_tab, av[1]); /* lookup context */
64			if (lp == NULL)
65			return(MG_EMEM);
66	greg	1.9	c_ccolor = (C_COLOR *)lp->data;
67	greg	1.1	if (ac == 2) { /* reestablish previous context */
68	greg	1.9	if (c_ccolor == NULL)
69	greg	1.1	return(MG_EUNDEF);
70			return(MG_OK);
71			}
72			if (av[2][0] != '=' \|\| av[2][1])
73			return(MG_ETYPE);
74	greg	1.9	if (c_ccolor == NULL) { /* create new color context */
75	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
76			if (lp->key == NULL)
77			return(MG_EMEM);
78			strcpy(lp->key, av[1]);
79			lp->data = (char *)malloc(sizeof(C_COLOR));
80			if (lp->data == NULL)
81			return(MG_EMEM);
82	greg	1.9	c_ccolor = (C_COLOR *)lp->data;
83			c_ccolor->clock = 0;
84	greg	1.1	}
85			if (ac == 3) { /* use default template */
86	greg	1.9	i = c_ccolor->clock;
87	greg	1.1	*c_ccolor = c_dfcolor;
88	greg	1.9	c_ccolor->name = av[1];
89			c_ccolor->clock = i + 1;
90	greg	1.1	return(MG_OK);
91			}
92			lp = lu_find(&clr_tab, av[3]); /* lookup template */
93			if (lp == NULL)
94			return(MG_EMEM);
95			if (lp->data == NULL)
96			return(MG_EUNDEF);
97	greg	1.9	i = c_ccolor->clock;
98	greg	1.1	c_ccolor = (C_COLOR *)lp->data;
99	greg	1.9	c_ccolor->name = av[1];
100			c_ccolor->clock = i + 1;
101	greg	1.1	return(MG_OK);
102			case MG_E_CXY: /* assign CIE XY value */
103			if (ac != 3)
104			return(MG_EARGC);
105			if (!isflt(av[1]) \|\| !isflt(av[2]))
106			return(MG_ETYPE);
107			c_ccolor->cx = atof(av[1]);
108			c_ccolor->cy = atof(av[2]);
109	greg	1.5	c_ccolor->flags = C_CDXY\|C_CSXY;
110	greg	1.1	if (c_ccolor->cx < 0. \| c_ccolor->cy < 0. \|
111			c_ccolor->cx + c_ccolor->cy > 1.)
112			return(MG_EILL);
113	greg	1.8	c_ccolor->clock++;
114	greg	1.1	return(MG_OK);
115	greg	1.5	case MG_E_CSPEC: /* assign spectral values */
116			if (ac < 5)
117			return(MG_EARGC);
118			if (!isint(av[1]) \|\| !isint(av[2]))
119			return(MG_ETYPE);
120			return(setspectrum(c_ccolor, atoi(av[1]), atoi(av[2]),
121			ac-3, av+3));
122			case MG_E_CMIX: /* mix colors */
123			if (ac < 5 \|\| (ac-1)%2)
124			return(MG_EARGC);
125			if (!isflt(av[1]))
126			return(MG_ETYPE);
127			wsum = atof(av[1]);
128			if (wsum < 0.)
129			return(MG_EILL);
130			if ((lp = lu_find(&clr_tab, av[2])) == NULL)
131			return(MG_EMEM);
132			if (lp->data == NULL)
133			return(MG_EUNDEF);
134			c_ccolor = (C_COLOR *)lp->data;
135			for (i = 3; i < ac; i += 2) {
136			if (!isflt(av[i]))
137			return(MG_ETYPE);
138			w = atof(av[i]);
139			if (w < 0.)
140			return(MG_EILL);
141			if ((lp = lu_find(&clr_tab, av[i+1])) == NULL)
142			return(MG_EMEM);
143			if (lp->data == NULL)
144			return(MG_EUNDEF);
145			mixcolors(c_ccolor, wsum, c_ccolor,
146			w, (C_COLOR *)lp->data);
147			wsum += w;
148			}
149			return(MG_OK);
150	greg	1.1	}
151			return(MG_EUNK);
152			}
153
154
155			int
156			c_hmaterial(ac, av) /* handle material entity */
157			int ac;
158			register char **av;
159			{
160	greg	1.9	int i;
161	greg	1.1	register LUENT *lp;
162
163			switch (mg_entity(av[0])) {
164			case MG_E_MATERIAL: /* get/set material context */
165	greg	1.4	if (ac > 4)
166			return(MG_EARGC);
167	greg	1.1	if (ac == 1) { /* set unnamed material context */
168			c_unmaterial = c_dfmaterial;
169			c_cmaterial = &c_unmaterial;
170			return(MG_OK);
171			}
172			lp = lu_find(&mat_tab, av[1]); /* lookup context */
173			if (lp == NULL)
174			return(MG_EMEM);
175	greg	1.9	c_cmaterial = (C_MATERIAL *)lp->data;
176	greg	1.1	if (ac == 2) { /* reestablish previous context */
177	greg	1.9	if (c_cmaterial == NULL)
178	greg	1.1	return(MG_EUNDEF);
179			return(MG_OK);
180			}
181			if (av[2][0] != '=' \|\| av[2][1])
182			return(MG_ETYPE);
183	greg	1.9	if (c_cmaterial == NULL) { /* create new material */
184	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
185			if (lp->key == NULL)
186			return(MG_EMEM);
187			strcpy(lp->key, av[1]);
188			lp->data = (char *)malloc(sizeof(C_MATERIAL));
189			if (lp->data == NULL)
190			return(MG_EMEM);
191	greg	1.9	c_cmaterial = (C_MATERIAL *)lp->data;
192			c_cmaterial->clock = 0;
193	greg	1.1	}
194			if (ac == 3) { /* use default template */
195	greg	1.9	i = c_cmaterial->clock;
196	greg	1.1	*c_cmaterial = c_dfmaterial;
197	greg	1.9	c_cmaterial->name = av[1];
198			c_cmaterial->clock = i + 1;
199	greg	1.1	return(MG_OK);
200			}
201			lp = lu_find(&mat_tab, av[3]); /* lookup template */
202			if (lp == NULL)
203			return(MG_EMEM);
204			if (lp->data == NULL)
205			return(MG_EUNDEF);
206	greg	1.9	i = c_cmaterial->clock;
207	greg	1.1	c_cmaterial = (C_MATERIAL *)lp->data;
208	greg	1.9	c_cmaterial->name = av[1];
209			c_cmaterial->clock = i + 1;
210	greg	1.1	return(MG_OK);
211			case MG_E_RD: /* set diffuse reflectance */
212			if (ac != 2)
213			return(MG_EARGC);
214			if (!isflt(av[1]))
215			return(MG_ETYPE);
216			c_cmaterial->rd = atof(av[1]);
217			if (c_cmaterial->rd < 0. \| c_cmaterial->rd > 1.)
218			return(MG_EILL);
219			c_cmaterial->rd_c = *c_ccolor;
220	greg	1.2	c_cmaterial->clock++;
221	greg	1.1	return(MG_OK);
222			case MG_E_ED: /* set diffuse emittance */
223			if (ac != 2)
224			return(MG_EARGC);
225			if (!isflt(av[1]))
226			return(MG_ETYPE);
227			c_cmaterial->ed = atof(av[1]);
228			if (c_cmaterial->ed < 0.)
229			return(MG_EILL);
230			c_cmaterial->ed_c = *c_ccolor;
231	greg	1.2	c_cmaterial->clock++;
232	greg	1.1	return(MG_OK);
233			case MG_E_TD: /* set diffuse transmittance */
234			if (ac != 2)
235			return(MG_EARGC);
236			if (!isflt(av[1]))
237			return(MG_ETYPE);
238			c_cmaterial->td = atof(av[1]);
239			if (c_cmaterial->td < 0. \| c_cmaterial->td > 1.)
240			return(MG_EILL);
241			c_cmaterial->td_c = *c_ccolor;
242	greg	1.8	c_cmaterial->clock++;
243	greg	1.1	return(MG_OK);
244			case MG_E_RS: /* set specular reflectance */
245			if (ac != 3)
246			return(MG_EARGC);
247			if (!isflt(av[1]) \|\| !isflt(av[2]))
248			return(MG_ETYPE);
249			c_cmaterial->rs = atof(av[1]);
250			c_cmaterial->rs_a = atof(av[2]);
251			if (c_cmaterial->rs < 0. \| c_cmaterial->rs > 1. \|
252			c_cmaterial->rs_a < 0.)
253			return(MG_EILL);
254			c_cmaterial->rs_c = *c_ccolor;
255	greg	1.2	c_cmaterial->clock++;
256	greg	1.1	return(MG_OK);
257			case MG_E_TS: /* set specular transmittance */
258			if (ac != 3)
259			return(MG_EARGC);
260			if (!isflt(av[1]) \|\| !isflt(av[2]))
261			return(MG_ETYPE);
262			c_cmaterial->ts = atof(av[1]);
263			c_cmaterial->ts_a = atof(av[2]);
264			if (c_cmaterial->ts < 0. \| c_cmaterial->ts > 1. \|
265			c_cmaterial->ts_a < 0.)
266			return(MG_EILL);
267			c_cmaterial->ts_c = *c_ccolor;
268	greg	1.2	c_cmaterial->clock++;
269	greg	1.1	return(MG_OK);
270			}
271			return(MG_EUNK);
272			}
273
274
275			int
276			c_hvertex(ac, av) /* handle a vertex entity */
277			int ac;
278			register char **av;
279			{
280	greg	1.9	int i;
281	greg	1.1	register LUENT *lp;
282
283			switch (mg_entity(av[0])) {
284			case MG_E_VERTEX: /* get/set vertex context */
285	greg	1.4	if (ac > 4)
286			return(MG_EARGC);
287	greg	1.1	if (ac == 1) { /* set unnamed vertex context */
288			c_unvertex = c_dfvertex;
289			c_cvertex = &c_unvertex;
290			return(MG_OK);
291			}
292			lp = lu_find(&vtx_tab, av[1]); /* lookup context */
293			if (lp == NULL)
294			return(MG_EMEM);
295	greg	1.9	c_cvertex = (C_VERTEX *)lp->data;
296	greg	1.1	if (ac == 2) { /* reestablish previous context */
297	greg	1.9	if (c_cvertex == NULL)
298	greg	1.1	return(MG_EUNDEF);
299			return(MG_OK);
300			}
301			if (av[2][0] != '=' \|\| av[2][1])
302			return(MG_ETYPE);
303	greg	1.9	if (c_cvertex == NULL) { /* create new vertex context */
304	greg	1.1	lp->key = (char *)malloc(strlen(av[1])+1);
305			if (lp->key == NULL)
306			return(MG_EMEM);
307			strcpy(lp->key, av[1]);
308			lp->data = (char *)malloc(sizeof(C_VERTEX));
309			if (lp->data == NULL)
310			return(MG_EMEM);
311	greg	1.9	c_cvertex = (C_VERTEX *)lp->data;
312	greg	1.1	}
313			if (ac == 3) { /* use default template */
314	greg	1.9	i = c_cvertex->clock;
315	greg	1.1	*c_cvertex = c_dfvertex;
316	greg	1.9	c_cvertex->name = av[1];
317			c_cvertex->clock = i + 1;
318	greg	1.1	return(MG_OK);
319			}
320			lp = lu_find(&vtx_tab, av[3]); /* lookup template */
321			if (lp == NULL)
322			return(MG_EMEM);
323			if (lp->data == NULL)
324			return(MG_EUNDEF);
325	greg	1.9	i = c_cvertex->clock;
326	greg	1.1	c_cvertex = (C_VERTEX *)lp->data;
327	greg	1.9	c_cvertex->name = av[1];
328			c_cvertex->clock = i + 1;
329	greg	1.1	return(MG_OK);
330			case MG_E_POINT: /* set point */
331			if (ac != 4)
332			return(MG_EARGC);
333			if (!isflt(av[1]) \|\| !isflt(av[2]) \|\| !isflt(av[3]))
334			return(MG_ETYPE);
335			c_cvertex->p[0] = atof(av[1]);
336			c_cvertex->p[1] = atof(av[2]);
337			c_cvertex->p[2] = atof(av[3]);
338	greg	1.8	c_cvertex->clock++;
339	greg	1.1	return(MG_OK);
340			case MG_E_NORMAL: /* set normal */
341			if (ac != 4)
342			return(MG_EARGC);
343			if (!isflt(av[1]) \|\| !isflt(av[2]) \|\| !isflt(av[3]))
344			return(MG_ETYPE);
345			c_cvertex->n[0] = atof(av[1]);
346			c_cvertex->n[1] = atof(av[2]);
347			c_cvertex->n[2] = atof(av[3]);
348			(void)normalize(c_cvertex->n);
349	greg	1.8	c_cvertex->clock++;
350	greg	1.1	return(MG_OK);
351			}
352			return(MG_EUNK);
353			}
354
355
356			void
357			c_clearall() /* empty context tables */
358			{
359			c_uncolor = c_dfcolor;
360			c_ccolor = &c_uncolor;
361	greg	1.3	lu_done(&clr_tab);
362	greg	1.1	c_unmaterial = c_dfmaterial;
363			c_cmaterial = &c_unmaterial;
364	greg	1.3	lu_done(&mat_tab);
365	greg	1.1	c_unvertex = c_dfvertex;
366			c_cvertex = &c_unvertex;
367	greg	1.3	lu_done(&vtx_tab);
368	greg	1.1	}
369
370
371			C_VERTEX *
372			c_getvert(name) /* get a named vertex */
373			char *name;
374			{
375			register LUENT *lp;
376
377			if ((lp = lu_find(&vtx_tab, name)) == NULL)
378			return(NULL);
379			return((C_VERTEX *)lp->data);
380	greg	1.5	}
381
382
383	greg	1.7	C_COLOR *
384			c_getcolor(name) /* get a named color */
385			char *name;
386			{
387			register LUENT *lp;
388
389			if ((lp = lu_find(&clr_tab, name)) == NULL)
390			return(NULL);
391			return((C_COLOR *)lp->data);
392			}
393
394
395	greg	1.5	int
396			c_isgrey(clr) /* check if color is grey */
397			register C_COLOR *clr;
398			{
399	greg	1.8	if (!(clr->flags & (C_CSXY\|C_CSSPEC)))
400	greg	1.5	return(1); /* no settings == grey */
401			c_ccvt(clr, C_CSXY);
402			return(clr->cx >= .323 && clr->cx <= .343 &&
403			clr->cy >= .323 && clr->cy <= .343);
404			}
405
406
407			void
408			c_ccvt(clr, fl) /* convert color representations */
409			register C_COLOR *clr;
410			int fl;
411			{
412			double x, y, z;
413			register int i;
414
415			if (clr->flags & fl) /* already done */
416			return;
417	greg	1.8	if (!(clr->flags & (C_CSXY\|C_CSSPEC))) /* nothing set! */
418	greg	1.5	*clr = c_dfcolor;
419			else if (fl & C_CSXY) { /* cspec -> cxy */
420			x = y = z = 0.;
421			for (i = 0; i < C_CNSS; i++) {
422			x += cie_xf.ssamp[i] * clr->ssamp[i];
423			y += cie_yf.ssamp[i] * clr->ssamp[i];
424			z += cie_zf.ssamp[i] * clr->ssamp[i];
425			}
426			z += x + y;
427			clr->cx = x / z;
428			clr->cy = y / z;
429			clr->flags \|= C_CSXY;
430			} else { /* cxy -> cspec */
431			z = (cie_xf.ssum + cie_yf.ssum + cie_zf.ssum) / 3.;
432			x = clr->cx * z / cie_xf.ssum;
433			y = clr->cy * z / cie_yf.ssum;
434			z = (1. - clr->cx - clr->cy) * z / cie_zf.ssum;
435			clr->ssum = 0;
436			for (i = 0; i < C_CNSS; i++)
437			clr->ssum += clr->ssamp[i] =
438			x * cie_xf.ssamp[i] +
439			y * cie_yf.ssamp[i] +
440			z * cie_zf.ssamp[i] ;
441			clr->flags \|= C_CSSPEC;
442			}
443			}
444
445
446			static int
447			setspectrum(clr, wlmin, wlmax, ac, av) /* convert a spectrum */
448			register C_COLOR *clr;
449			int wlmin, wlmax;
450			int ac;
451			char **av;
452			{
453			double scale;
454			float *va;
455			register int i;
456			int wl, pos;
457			double wl0, wlstep;
458
459			if (wlmin < C_CMINWL \|\| wlmin >= wlmax \|\| wlmax > C_CMAXWL)
460			return(MG_EILL);
461			if ((va = (float )malloc(acsizeof(float))) == NULL)
462			return(MG_EMEM);
463			scale = 0.; /* get values and maximum */
464			for (i = 0; i < ac; i++) {
465			if (!isflt(av[i]))
466			return(MG_ETYPE);
467			va[i] = atof(av[i]);
468			if (va[i] < 0.)
469			return(MG_EILL);
470			if (va[i] > scale)
471			scale = va[i];
472			}
473			if (scale == 0.)
474			return(MG_EILL);
475			scale = C_CMAXV / scale;
476			clr->ssum = 0; /* convert to our spacing */
477			wl0 = wlmin;
478			wlstep = (double)(wlmax - wlmin)/(ac-1);
479			pos = 0;
480			for (i = 0, wl = C_CMINWL; i < C_CNSS; i++, wl += C_CWLI)
481			if (wl < wlmin \|\| wl > wlmax)
482			clr->ssamp[i] = 0;
483			else {
484			while (wl0 + wlstep < wl+FTINY) {
485			wl0 += wlstep;
486			pos++;
487			}
488			if (wl+FTINY >= wl0 && wl-FTINY <= wl0)
489			clr->ssamp[i] = scale*va[pos];
490			else /* interpolate if necessary */
491			clr->ssamp[i] = scale / wlstep *
492			( va[pos]*(wl0+wlstep - wl) +
493			va[pos+1]*(wl - wl0) );
494			clr->ssum += clr->ssamp[i];
495			}
496			clr->flags = C_CDSPEC\|C_CSSPEC;
497	greg	1.8	clr->clock++;
498	greg	1.5	free((MEM_PTR)va);
499			return(MG_OK);
500			}
501
502
503			static void
504			mixcolors(cres, w1, c1, w2, c2) /* mix two colors according to weights given */
505			register C_COLOR cres, c1, *c2;
506			double w1, w2;
507			{
508			double scale;
509			float cmix[C_CNSS];
510			register int i;
511
512			if ((c1->flags\|c2->flags) & C_CDSPEC) { /* spectral mixing */
513			c_ccvt(c1, C_CSSPEC);
514			c_ccvt(c2, C_CSSPEC);
515			w1 /= (double)c1->ssum;
516			w2 /= (double)c2->ssum;
517			scale = 0.;
518			for (i = 0; i < C_CNSS; i++) {
519			cmix[i] = w1c1->ssamp[i] + w2c2->ssamp[i];
520			if (cmix[i] > scale)
521			scale = cmix[i];
522			}
523			scale = C_CMAXV / scale;
524			cres->ssum = 0;
525			for (i = 0; i < C_CNSS; i++)
526			cres->ssum += cres->ssamp[i] = scale*cmix[i] + .5;
527			cres->flags = C_CDSPEC\|C_CSSPEC;
528			} else { /* CIE xy mixing */
529			c_ccvt(c1, C_CSXY);
530			c_ccvt(c2, C_CSXY);
531			scale = 1. / (w1/c1->cy + w2/c2->cy);
532			cres->cx = (c1->cxw1/c1->cy + c2->cxw2/c2->cy) * scale;
533			cres->cy = (w1 + w2) * scale;
534			cres->flags = C_CDXY\|C_CSXY;
535			}
536	greg	1.8	cres->clock++; /* record the change */
537	greg	1.1	}