src/hd/rhd_qtree.c

/* Copyright (c) 1997 Silicon Graphics, Inc. */

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

/*
 * Quadtree driver support routines.
 */

#include "standard.h"
#include "rhd_qtree.h"
                                /* quantity of leaves to free at a time */
#ifndef LFREEPCT
#define LFREEPCT        25
#endif
                                /* maximum allowed angle difference (deg.) */
#ifndef MAXANG
#define MAXANG          20.
#endif

#define MAXDIFF2        (PI*PI/180./180.* MAXANG*MAXANG )

#define abs(i)          ((i) < 0 ? -(i) : (i))

RTREE   qtrunk;                 /* our quadtree trunk */
double  qtDepthEps = .05;       /* epsilon to compare depths (z fraction) */
int     qtMinNodesiz = 2;       /* minimum node dimension (pixels) */
struct rleaves  qtL;            /* our pile of leaves */

#define TBUNDLESIZ      409     /* number of twigs in a bundle */

static RTREE    **twigbundle;   /* free twig blocks (NULL term.) */
static int      nexttwig;       /* next free twig */

#define ungetleaf(li)   (qtL.tl=(li))   /* dangerous if used improperly */


static RTREE *
newtwig()                       /* allocate a twig */
{
        register int    bi;

        if (twigbundle == NULL) {       /* initialize */
                twigbundle = (RTREE **)malloc(sizeof(RTREE *));
                if (twigbundle == NULL)
                        goto memerr;
                twigbundle[0] = NULL;
        }
        bi = nexttwig / TBUNDLESIZ;
        if (twigbundle[bi] == NULL) {   /* new block */
                twigbundle = (RTREE **)realloc((char *)twigbundle,
                                        (bi+2)*sizeof(RTREE *));
                if (twigbundle == NULL)
                        goto memerr;
                twigbundle[bi] = (RTREE *)calloc(TBUNDLESIZ, sizeof(RTREE));
                if (twigbundle[bi] == NULL)
                        goto memerr;
                twigbundle[bi+1] = NULL;
        }
                                /* nexttwig++ % TBUNDLESIZ */
        return(twigbundle[bi] + (nexttwig++ - bi*TBUNDLESIZ));
memerr:
        error(SYSTEM, "out of memory in newtwig");
}


qtFreeTree(really)              /* free allocated twigs */
int     really;
{
        register int    i;

        qtrunk.flgs = CH_ANY;   /* chop down tree */
        if (twigbundle == NULL)
                return;
        i = (TBUNDLESIZ-1+nexttwig)/TBUNDLESIZ;
        nexttwig = 0;
        if (!really) {          /* just clear allocated blocks */
                while (i--)
                        bzero((char *)twigbundle[i], TBUNDLESIZ*sizeof(RTREE));
                return;
        }
                                /* else "really" means free up memory */
        for (i = 0; twigbundle[i] != NULL; i++)
                free((char *)twigbundle[i]);
        free((char *)twigbundle);
        twigbundle = NULL;
}


static int
newleaf()                       /* allocate a leaf from our pile */
{
        int     li;
        
        li = qtL.tl++;
        if (qtL.tl >= qtL.nl)   /* get next leaf in ring */
                qtL.tl = 0;
        if (qtL.tl == qtL.bl)   /* need to shake some free */
                qtCompost(LFREEPCT);
        return(li);
}


#define LEAFSIZ         (3*sizeof(float)+sizeof(int4)+\
                        sizeof(TMbright)+6*sizeof(BYTE))

int
qtAllocLeaves(n)                /* allocate space for n leaves */
register int    n;
{
        unsigned        nbytes;
        register unsigned       i;

        qtFreeTree(0);          /* make sure tree is empty */
        if (n <= 0)
                return(0);
        if (qtL.nl >= n)
                return(qtL.nl);
        else if (qtL.nl > 0)
                free(qtL.base);
                                /* round space up to nearest power of 2 */
        nbytes = n*LEAFSIZ + 8;
        for (i = 1024; nbytes > i; i <<= 1)
                ;
        n = (i - 8) / LEAFSIZ;  /* should we make sure n is even? */
        qtL.base = (char *)malloc(n*LEAFSIZ);
        if (qtL.base == NULL)
                return(0);
                                /* assign larger alignment types earlier */
        qtL.wp = (float (*)[3])qtL.base;
        qtL.wd = (int4 *)(qtL.wp + n);
        qtL.brt = (TMbright *)(qtL.wd + n);
        qtL.chr = (BYTE (*)[3])(qtL.brt + n);
        qtL.rgb = (BYTE (*)[3])(qtL.chr + n);
        qtL.nl = n;
        qtL.tml = qtL.bl = qtL.tl = 0;
        return(n);
}

#undef  LEAFSIZ


qtFreeLeaves()                  /* free our allocated leaves and twigs */
{
        qtFreeTree(1);          /* free tree also */
        if (qtL.nl <= 0)
                return;
        free(qtL.base);
        qtL.base = NULL;
        qtL.nl = 0;
}


static
shaketree(tp)                   /* shake dead leaves from tree */
register RTREE  *tp;
{
        register int    i, li;

        for (i = 0; i < 4; i++)
                if (tp->flgs & BRF(i)) {
                        shaketree(tp->k[i].b);
                        if (is_stump(tp->k[i].b))
                                tp->flgs &= ~BRF(i);
                } else if (tp->flgs & LFF(i)) {
                        li = tp->k[i].li;
                        if (qtL.bl < qtL.tl ?
                                (li < qtL.bl || li >= qtL.tl) :
                                (li < qtL.bl && li >= qtL.tl))
                                tp->flgs &= ~LFF(i);
                }
}


int
qtCompost(pct)                  /* free up some leaves */
int     pct;
{
        int     nused, nclear, nmapped;

                                /* figure out how many leaves to clear */
        nclear = qtL.nl * pct / 100;
        nused = qtL.tl - qtL.bl;
        if (nused <= 0) nused += qtL.nl;
        nclear -= qtL.nl - nused;
        if (nclear <= 0)
                return(0);
        if (nclear >= nused) {  /* clear them all */
                qtFreeTree(0);
                qtL.tml = qtL.bl = qtL.tl = 0;
                return(nused);
        }
                                /* else clear leaves from bottom */
        nmapped = qtL.tml - qtL.bl;
        if (nmapped < 0) nmapped += qtL.nl;
        qtL.bl += nclear;
        if (qtL.bl >= qtL.nl) qtL.bl -= qtL.nl;
        if (nmapped <= nclear) qtL.tml = qtL.bl;
        shaketree(&qtrunk);
        return(nclear);
}


#define DCSCALE         11585.2         /* (1<<13)*sqrt(2) */
#define FXNEG           01
#define FYNEG           02
#define FZNEG           04
#define FXACT           010
#define FZACT           020
#define F1SFT           5
#define F2SFT           18
#define FMASK           0x1fff

static int4
encodedir(dv)           /* encode a normalized direction vector */
FVECT   dv;
{
        register int4   dc = 0;
        int     cd[3], cm;
        register int    i;

        for (i = 0; i < 3; i++)
                if (dv[i] < 0.) {
                        cd[i] = dv[i] * -DCSCALE;
                        dc |= 1<<i;
                } else
                        cd[i] = dv[i] * DCSCALE;
        if (cd[0] <= cd[1]) {
                dc |= FXACT | cd[0] << F1SFT;
                cm = cd[1];
        } else {
                dc |= cd[1] << F1SFT;
                cm = cd[0];
        }
        if (cd[2] <= cm)
                dc |= FZACT | cd[2] << F2SFT;
        else
                dc |= cm << F2SFT;
        return(dc);
}


static
decodedir(dv, dc)       /* decode a normalized direction vector */
FVECT   dv;     /* returned */
register int4   dc;
{
        double  d1, d2, der;

        d1 = ((dc>>F1SFT & FMASK)+.5)/DCSCALE;
        d2 = ((dc>>F2SFT & FMASK)+.5)/DCSCALE;
        der = sqrt(1. - d1*d1 - d2*d2);
        if (dc & FXACT) {
                dv[0] = d1;
                if (dc & FZACT) { dv[1] = der; dv[2] = d2; }
                else { dv[1] = d2; dv[2] = der; }
        } else {
                dv[1] = d1;
                if (dc & FZACT) { dv[0] = der; dv[2] = d2; }
                else { dv[0] = d2; dv[2] = der; }
        }
        if (dc & FXNEG) dv[0] = -dv[0];
        if (dc & FYNEG) dv[1] = -dv[1];
        if (dc & FZNEG) dv[2] = -dv[2];
}


static double
dir2diff(dc1, dc2)              /* relative radians^2 between directions */
int4    dc1, dc2;
{
        FVECT   v1, v2;

        decodedir(v1, dc1);
        decodedir(v2, dc2);

        return(2. - 2.*DOT(v1,v2));
}


static double
fdir2diff(dc1, v2)              /* relative radians^2 between directions */
int4    dc1;
register FVECT  v2;
{
        FVECT   v1;

        decodedir(v1, dc1);

        return(2. - 2.*DOT(v1,v2));
}


int
qtFindLeaf(x, y)                /* find closest leaf to (x,y) */
int     x, y;
{
        register RTREE  *tp = &qtrunk;
        int     li = -1;
        int     x0=0, y0=0, x1=odev.hres, y1=odev.vres;
        int     mx, my;
        register int    q;
                                        /* check limits */
        if (x < 0 || x >= odev.hres || y < 0 || y >= odev.vres)
                return(-1);
                                        /* find nearby leaf in our tree */
        for ( ; ; ) {
                for (q = 0; q < 4; q++)         /* find any leaf this level */
                        if (tp->flgs & LFF(q)) {
                                li = tp->k[q].li;
                                break;
                        }
                q = 0;                          /* which quadrant are we? */
                mx = (x0 + x1) >> 1;
                my = (y0 + y1) >> 1;
                if (x < mx) x1 = mx;
                else {x0 = mx; q |= 01;}
                if (y < my) y1 = my;
                else {y0 = my; q |= 02;}
                if (tp->flgs & BRF(q)) {        /* branch down if not a leaf */
                        tp = tp->k[q].b;
                        continue;
                }
                if (tp->flgs & LFF(q))          /* good shot! */
                        return(tp->k[q].li);
                return(li);                     /* else return what we have */
        }
}


static
addleaf(li)                     /* add a leaf to our tree */
int     li;
{
        register RTREE  *tp = &qtrunk;
        int     x0=0, y0=0, x1=odev.hres, y1=odev.vres;
        int     lo = -1;
        double  d2;
        int     x, y, mx, my;
        double  z;
        FVECT   ip, wp, vd;
        register int    q;
                                        /* compute leaf location in view */
        VCOPY(wp, qtL.wp[li]);
        viewloc(ip, &odev.v, wp);
        if (ip[2] <= 0. || ip[0] < 0. || ip[0] >= 1.
                        || ip[1] < 0. || ip[1] >= 1.)
                return(0);                      /* behind or outside view */
#ifdef DEBUG
        if (odev.v.type == VT_PAR | odev.v.vfore > FTINY)
                error(INTERNAL, "bad view assumption in addleaf");
#endif
        for (q = 0; q < 3; q++)
                vd[q] = (wp[q] - odev.v.vp[q])/ip[2];
        d2 = fdir2diff(qtL.wd[li], vd);
        if (d2 > MAXDIFF2)
                return(0);                      /* leaf dir. too far off */
        x = ip[0] * odev.hres;
        y = ip[1] * odev.vres;
        z = ip[2];
                                        /* find the place for it */
        for ( ; ; ) {
                q = 0;                          /* which quadrant? */
                mx = (x0 + x1) >> 1;
                my = (y0 + y1) >> 1;
                if (x < mx) x1 = mx;
                else {x0 = mx; q |= 01;}
                if (y < my) y1 = my;
                else {y0 = my; q |= 02;}
                if (tp->flgs & BRF(q)) {        /* move to next branch */
                        tp->flgs |= CHF(q);             /* not sure; guess */
                        tp = tp->k[q].b;
                        continue;
                }
                if (!(tp->flgs & LFF(q))) {     /* found stem for leaf */
                        tp->k[q].li = li;
                        tp->flgs |= CHLFF(q);
                        break;
                }       
                if (lo != tp->k[q].li) {        /* check old leaf */
                        lo = tp->k[q].li;
                        VCOPY(wp, qtL.wp[lo]);
                        viewloc(ip, &odev.v, wp);
                }
                                                /* is node minimum size? */
                if (y1-y0 <= qtMinNodesiz || x1-x0 <= qtMinNodesiz) {
                        if (z > (1.+qtDepthEps)*ip[2])
                                return(0);              /* old one closer */
                        if (z >= (1.-qtDepthEps)*ip[2] &&
                                        fdir2diff(qtL.wd[lo], vd) < d2)
                                return(0);              /* old one better */
                        tp->k[q].li = li;               /* else new one is */
                        tp->flgs |= CHF(q);
                        break;
                }
                tp->flgs &= ~LFF(q);            /* else grow tree */
                tp->flgs |= CHBRF(q);
                tp = tp->k[q].b = newtwig();
                q = 0;                          /* old leaf -> new branch */
                mx = ip[0] * odev.hres;
                my = ip[1] * odev.vres;
                if (mx >= (x0 + x1) >> 1) q |= 01;
                if (my >= (y0 + y1) >> 1) q |= 02;
                tp->flgs = CH_ANY|LFF(q);       /* all new */
                tp->k[q].li = lo;
        }
        return(1);              /* done */
}


dev_value(c, p, v)              /* add a pixel value to our quadtree */
COLR    c;
FVECT   p, v;
{
        register int    li;

        li = newleaf();
        VCOPY(qtL.wp[li], p);
        qtL.wd[li] = encodedir(v);
        tmCvColrs(&qtL.brt[li], qtL.chr[li], c, 1);
        if (!addleaf(li))
                ungetleaf(li);
}


qtReplant()                     /* replant our tree using new view */
{
        register int    i;
                                        /* anything to replant? */
        if (qtL.bl == qtL.tl)
                return;
        qtFreeTree(0);                  /* blow the old tree away */
                                        /* regrow it in new place */
        for (i = qtL.bl; i != qtL.tl; ) {
                addleaf(i);
                if (++i >= qtL.nl) i = 0;
        }
}


qtMapLeaves(redo)               /* map our leaves to RGB */
int     redo;
{
        int     aorg, alen, borg, blen;
                                        /* recompute mapping? */
        if (redo)
                qtL.tml = qtL.bl;
                                        /* already done? */
        if (qtL.tml == qtL.tl)
                return(1);
                                        /* compute segments */
        aorg = qtL.tml;
        if (qtL.tl >= aorg) {
                alen = qtL.tl - aorg;
                blen = 0;
        } else {
                alen = qtL.nl - aorg;
                borg = 0;
                blen = qtL.tl;
        }
                                        /* (re)compute tone mapping? */
        if (qtL.tml == qtL.bl) {
                tmClearHisto();
                tmAddHisto(qtL.brt+aorg, alen, 1);
                if (blen > 0)
                        tmAddHisto(qtL.brt+borg, blen, 1);
                if (tmComputeMapping(0., 0., 0.) != TM_E_OK)
                        return(0);
        }
        if (tmMapPixels(qtL.rgb+aorg, qtL.brt+aorg,
                        qtL.chr+aorg, alen) != TM_E_OK)
                return(0);
        if (blen > 0)
                tmMapPixels(qtL.rgb+borg, qtL.brt+borg,
                                qtL.chr+borg, blen);
        qtL.tml = qtL.tl;
        return(1);
}
Revision:	3.11
Committed:	Fri Dec 5 15:40:54 1997 UTC (27 years, 10 months ago) by gregl
Content type:	text/plain
Branch:	MAIN
Changes since 3.10:	+82 -54 lines
Log Message:	change to better, faster angle-difference computation
#	User	Rev	Content
1	gregl	3.1	/* Copyright (c) 1997 Silicon Graphics, Inc. */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ SGI";
5			#endif
6
7			/*
8			* Quadtree driver support routines.
9			*/
10
11			#include "standard.h"
12			#include "rhd_qtree.h"
13	gregl	3.6	/* quantity of leaves to free at a time */
14			#ifndef LFREEPCT
15			#define LFREEPCT 25
16			#endif
17	gregl	3.10	/* maximum allowed angle difference (deg.) */
18			#ifndef MAXANG
19			#define MAXANG 20.
20			#endif
21	gregl	3.1
22	gregl	3.11	#define MAXDIFF2 (PIPI/180./180. MAXANG*MAXANG )
23	gregl	3.10
24			#define abs(i) ((i) < 0 ? -(i) : (i))
25
26	gregl	3.2	RTREE qtrunk; /* our quadtree trunk */
27	gregl	3.10	double qtDepthEps = .05; /* epsilon to compare depths (z fraction) */
28	gregl	3.2	int qtMinNodesiz = 2; /* minimum node dimension (pixels) */
29	gregl	3.5	struct rleaves qtL; /* our pile of leaves */
30	gregl	3.2
31	gregl	3.1	#define TBUNDLESIZ 409 /* number of twigs in a bundle */
32
33			static RTREE *twigbundle; / free twig blocks (NULL term.) */
34			static int nexttwig; /* next free twig */
35
36	gregl	3.10	#define ungetleaf(li) (qtL.tl=(li)) /* dangerous if used improperly */
37	gregl	3.1
38	gregl	3.10
39	gregl	3.1	static RTREE *
40			newtwig() /* allocate a twig */
41			{
42			register int bi;
43
44			if (twigbundle == NULL) { /* initialize */
45			twigbundle = (RTREE *)malloc(sizeof(RTREE ));
46			if (twigbundle == NULL)
47			goto memerr;
48			twigbundle[0] = NULL;
49			}
50			bi = nexttwig / TBUNDLESIZ;
51			if (twigbundle[bi] == NULL) { /* new block */
52			twigbundle = (RTREE *)realloc((char )twigbundle,
53			(bi+2)sizeof(RTREE ));
54			if (twigbundle == NULL)
55			goto memerr;
56			twigbundle[bi] = (RTREE *)calloc(TBUNDLESIZ, sizeof(RTREE));
57			if (twigbundle[bi] == NULL)
58			goto memerr;
59			twigbundle[bi+1] = NULL;
60			}
61			/* nexttwig++ % TBUNDLESIZ */
62			return(twigbundle[bi] + (nexttwig++ - bi*TBUNDLESIZ));
63			memerr:
64			error(SYSTEM, "out of memory in newtwig");
65			}
66
67
68	gregl	3.3	qtFreeTree(really) /* free allocated twigs */
69	gregl	3.1	int really;
70			{
71			register int i;
72
73	gregl	3.7	qtrunk.flgs = CH_ANY; /* chop down tree */
74	gregl	3.1	if (twigbundle == NULL)
75			return;
76	gregl	3.7	i = (TBUNDLESIZ-1+nexttwig)/TBUNDLESIZ;
77			nexttwig = 0;
78	gregl	3.1	if (!really) { /* just clear allocated blocks */
79	gregl	3.7	while (i--)
80	gregl	3.1	bzero((char )twigbundle[i], TBUNDLESIZsizeof(RTREE));
81			return;
82			}
83			/* else "really" means free up memory */
84			for (i = 0; twigbundle[i] != NULL; i++)
85			free((char *)twigbundle[i]);
86			free((char *)twigbundle);
87			twigbundle = NULL;
88			}
89
90
91	gregl	3.5	static int
92	gregl	3.1	newleaf() /* allocate a leaf from our pile */
93			{
94	gregl	3.5	int li;
95	gregl	3.4
96	gregl	3.5	li = qtL.tl++;
97			if (qtL.tl >= qtL.nl) /* get next leaf in ring */
98			qtL.tl = 0;
99			if (qtL.tl == qtL.bl) /* need to shake some free */
100	gregl	3.1	qtCompost(LFREEPCT);
101	gregl	3.5	return(li);
102	gregl	3.1	}
103
104
105	gregl	3.11	#define LEAFSIZ (3*sizeof(float)+sizeof(int4)+\
106	gregl	3.10	sizeof(TMbright)+6*sizeof(BYTE))
107	gregl	3.5
108	gregl	3.1	int
109			qtAllocLeaves(n) /* allocate space for n leaves */
110	gregl	3.5	register int n;
111	gregl	3.1	{
112			unsigned nbytes;
113			register unsigned i;
114
115	gregl	3.3	qtFreeTree(0); /* make sure tree is empty */
116	gregl	3.1	if (n <= 0)
117			return(0);
118	gregl	3.5	if (qtL.nl >= n)
119			return(qtL.nl);
120			else if (qtL.nl > 0)
121			free(qtL.base);
122	gregl	3.1	/* round space up to nearest power of 2 */
123	gregl	3.5	nbytes = n*LEAFSIZ + 8;
124	gregl	3.1	for (i = 1024; nbytes > i; i <<= 1)
125			;
126	gregl	3.5	n = (i - 8) / LEAFSIZ; /* should we make sure n is even? */
127			qtL.base = (char )malloc(nLEAFSIZ);
128			if (qtL.base == NULL)
129			return(0);
130			/* assign larger alignment types earlier */
131			qtL.wp = (float (*)[3])qtL.base;
132	gregl	3.11	qtL.wd = (int4 *)(qtL.wp + n);
133	gregl	3.10	qtL.brt = (TMbright *)(qtL.wd + n);
134	gregl	3.5	qtL.chr = (BYTE (*)[3])(qtL.brt + n);
135			qtL.rgb = (BYTE (*)[3])(qtL.chr + n);
136			qtL.nl = n;
137			qtL.tml = qtL.bl = qtL.tl = 0;
138			return(n);
139	gregl	3.1	}
140
141	gregl	3.5	#undef LEAFSIZ
142	gregl	3.1
143	gregl	3.5
144	gregl	3.1	qtFreeLeaves() /* free our allocated leaves and twigs */
145			{
146	gregl	3.3	qtFreeTree(1); /* free tree also */
147	gregl	3.5	if (qtL.nl <= 0)
148	gregl	3.1	return;
149	gregl	3.5	free(qtL.base);
150			qtL.base = NULL;
151			qtL.nl = 0;
152	gregl	3.1	}
153
154
155			static
156			shaketree(tp) /* shake dead leaves from tree */
157			register RTREE *tp;
158			{
159			register int i, li;
160
161			for (i = 0; i < 4; i++)
162	gregl	3.5	if (tp->flgs & BRF(i)) {
163	gregl	3.2	shaketree(tp->k[i].b);
164	gregl	3.5	if (is_stump(tp->k[i].b))
165			tp->flgs &= ~BRF(i);
166			} else if (tp->flgs & LFF(i)) {
167			li = tp->k[i].li;
168			if (qtL.bl < qtL.tl ?
169			(li < qtL.bl \|\| li >= qtL.tl) :
170			(li < qtL.bl && li >= qtL.tl))
171			tp->flgs &= ~LFF(i);
172	gregl	3.1	}
173			}
174
175
176			int
177			qtCompost(pct) /* free up some leaves */
178			int pct;
179			{
180	gregl	3.5	int nused, nclear, nmapped;
181	gregl	3.4
182	gregl	3.1	/* figure out how many leaves to clear */
183	gregl	3.5	nclear = qtL.nl * pct / 100;
184			nused = qtL.tl - qtL.bl;
185			if (nused <= 0) nused += qtL.nl;
186			nclear -= qtL.nl - nused;
187	gregl	3.1	if (nclear <= 0)
188			return(0);
189			if (nclear >= nused) { /* clear them all */
190	gregl	3.3	qtFreeTree(0);
191	gregl	3.5	qtL.tml = qtL.bl = qtL.tl = 0;
192	gregl	3.1	return(nused);
193			}
194			/* else clear leaves from bottom */
195	gregl	3.5	nmapped = qtL.tml - qtL.bl;
196			if (nmapped < 0) nmapped += qtL.nl;
197			qtL.bl += nclear;
198			if (qtL.bl >= qtL.nl) qtL.bl -= qtL.nl;
199			if (nmapped <= nclear) qtL.tml = qtL.bl;
200	gregl	3.1	shaketree(&qtrunk);
201			return(nclear);
202			}
203
204
205	gregl	3.11	#define DCSCALE 11585.2 /* (1<<13)sqrt(2) /
206			#define FXNEG 01
207			#define FYNEG 02
208			#define FZNEG 04
209			#define FXACT 010
210			#define FZACT 020
211			#define F1SFT 5
212			#define F2SFT 18
213			#define FMASK 0x1fff
214
215			static int4
216			encodedir(dv) /* encode a normalized direction vector */
217	gregl	3.10	FVECT dv;
218			{
219	gregl	3.11	register int4 dc = 0;
220			int cd[3], cm;
221			register int i;
222
223			for (i = 0; i < 3; i++)
224			if (dv[i] < 0.) {
225			cd[i] = dv[i] * -DCSCALE;
226			dc \|= 1<<i;
227			} else
228			cd[i] = dv[i] * DCSCALE;
229			if (cd[0] <= cd[1]) {
230			dc \|= FXACT \| cd[0] << F1SFT;
231			cm = cd[1];
232			} else {
233			dc \|= cd[1] << F1SFT;
234			cm = cd[0];
235	gregl	3.10	}
236	gregl	3.11	if (cd[2] <= cm)
237			dc \|= FZACT \| cd[2] << F2SFT;
238			else
239			dc \|= cm << F2SFT;
240			return(dc);
241	gregl	3.10	}
242
243
244	gregl	3.11	static
245			decodedir(dv, dc) /* decode a normalized direction vector */
246			FVECT dv; /* returned */
247			register int4 dc;
248			{
249			double d1, d2, der;
250	gregl	3.10
251	gregl	3.11	d1 = ((dc>>F1SFT & FMASK)+.5)/DCSCALE;
252			d2 = ((dc>>F2SFT & FMASK)+.5)/DCSCALE;
253			der = sqrt(1. - d1d1 - d2d2);
254			if (dc & FXACT) {
255			dv[0] = d1;
256			if (dc & FZACT) { dv[1] = der; dv[2] = d2; }
257			else { dv[1] = d2; dv[2] = der; }
258			} else {
259			dv[1] = d1;
260			if (dc & FZACT) { dv[0] = der; dv[2] = d2; }
261			else { dv[0] = d2; dv[2] = der; }
262			}
263			if (dc & FXNEG) dv[0] = -dv[0];
264			if (dc & FYNEG) dv[1] = -dv[1];
265			if (dc & FZNEG) dv[2] = -dv[2];
266			}
267	gregl	3.10
268	gregl	3.11
269			static double
270			dir2diff(dc1, dc2) /* relative radians^2 between directions */
271			int4 dc1, dc2;
272	gregl	3.10	{
273	gregl	3.11	FVECT v1, v2;
274	gregl	3.10
275	gregl	3.11	decodedir(v1, dc1);
276			decodedir(v2, dc2);
277
278			return(2. - 2.*DOT(v1,v2));
279	gregl	3.10	}
280
281
282	gregl	3.11	static double
283			fdir2diff(dc1, v2) /* relative radians^2 between directions */
284			int4 dc1;
285			register FVECT v2;
286	gregl	3.10	{
287	gregl	3.11	FVECT v1;
288	gregl	3.10
289	gregl	3.11	decodedir(v1, dc1);
290
291			return(2. - 2.*DOT(v1,v2));
292	gregl	3.10	}
293
294
295	gregl	3.5	int
296	gregl	3.3	qtFindLeaf(x, y) /* find closest leaf to (x,y) */
297			int x, y;
298			{
299			register RTREE *tp = &qtrunk;
300	gregl	3.5	int li = -1;
301	gregl	3.3	int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
302			int mx, my;
303			register int q;
304			/* check limits */
305			if (x < 0 \|\| x >= odev.hres \|\| y < 0 \|\| y >= odev.vres)
306	gregl	3.5	return(-1);
307	gregl	3.3	/* find nearby leaf in our tree */
308			for ( ; ; ) {
309			for (q = 0; q < 4; q++) /* find any leaf this level */
310	gregl	3.5	if (tp->flgs & LFF(q)) {
311			li = tp->k[q].li;
312	gregl	3.3	break;
313			}
314			q = 0; /* which quadrant are we? */
315			mx = (x0 + x1) >> 1;
316			my = (y0 + y1) >> 1;
317			if (x < mx) x1 = mx;
318			else {x0 = mx; q \|= 01;}
319			if (y < my) y1 = my;
320			else {y0 = my; q \|= 02;}
321			if (tp->flgs & BRF(q)) { /* branch down if not a leaf */
322			tp = tp->k[q].b;
323			continue;
324			}
325	gregl	3.5	if (tp->flgs & LFF(q)) /* good shot! */
326			return(tp->k[q].li);
327			return(li); /* else return what we have */
328	gregl	3.3	}
329			}
330
331
332	gregl	3.1	static
333	gregl	3.5	addleaf(li) /* add a leaf to our tree */
334			int li;
335	gregl	3.1	{
336			register RTREE *tp = &qtrunk;
337			int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
338	gregl	3.5	int lo = -1;
339	gregl	3.11	double d2;
340	gregl	3.1	int x, y, mx, my;
341			double z;
342	gregl	3.11	FVECT ip, wp, vd;
343	gregl	3.1	register int q;
344	gregl	3.10	/* compute leaf location in view */
345	gregl	3.5	VCOPY(wp, qtL.wp[li]);
346	gregl	3.1	viewloc(ip, &odev.v, wp);
347			if (ip[2] <= 0. \|\| ip[0] < 0. \|\| ip[0] >= 1.
348			\|\| ip[1] < 0. \|\| ip[1] >= 1.)
349	gregl	3.10	return(0); /* behind or outside view */
350			#ifdef DEBUG
351			if (odev.v.type == VT_PAR \| odev.v.vfore > FTINY)
352			error(INTERNAL, "bad view assumption in addleaf");
353			#endif
354			for (q = 0; q < 3; q++)
355	gregl	3.11	vd[q] = (wp[q] - odev.v.vp[q])/ip[2];
356			d2 = fdir2diff(qtL.wd[li], vd);
357	gregl	3.10	if (d2 > MAXDIFF2)
358			return(0); /* leaf dir. too far off */
359	gregl	3.1	x = ip[0] * odev.hres;
360			y = ip[1] * odev.vres;
361			z = ip[2];
362			/* find the place for it */
363			for ( ; ; ) {
364			q = 0; /* which quadrant? */
365			mx = (x0 + x1) >> 1;
366			my = (y0 + y1) >> 1;
367			if (x < mx) x1 = mx;
368			else {x0 = mx; q \|= 01;}
369			if (y < my) y1 = my;
370			else {y0 = my; q \|= 02;}
371			if (tp->flgs & BRF(q)) { /* move to next branch */
372			tp->flgs \|= CHF(q); /* not sure; guess */
373			tp = tp->k[q].b;
374			continue;
375			}
376	gregl	3.5	if (!(tp->flgs & LFF(q))) { /* found stem for leaf */
377			tp->k[q].li = li;
378			tp->flgs \|= CHLFF(q);
379	gregl	3.1	break;
380			}
381	gregl	3.10	if (lo != tp->k[q].li) { /* check old leaf */
382	gregl	3.5	lo = tp->k[q].li;
383			VCOPY(wp, qtL.wp[lo]);
384	gregl	3.1	viewloc(ip, &odev.v, wp);
385			}
386			/* is node minimum size? */
387	gregl	3.10	if (y1-y0 <= qtMinNodesiz \|\| x1-x0 <= qtMinNodesiz) {
388			if (z > (1.+qtDepthEps)*ip[2])
389			return(0); /* old one closer */
390			if (z >= (1.-qtDepthEps)*ip[2] &&
391	gregl	3.11	fdir2diff(qtL.wd[lo], vd) < d2)
392	gregl	3.10	return(0); /* old one better */
393			tp->k[q].li = li; /* else new one is */
394	gregl	3.1	tp->flgs \|= CHF(q);
395			break;
396			}
397	gregl	3.5	tp->flgs &= ~LFF(q); /* else grow tree */
398			tp->flgs \|= CHBRF(q);
399	gregl	3.1	tp = tp->k[q].b = newtwig();
400			q = 0; /* old leaf -> new branch */
401			mx = ip[0] * odev.hres;
402			my = ip[1] * odev.vres;
403			if (mx >= (x0 + x1) >> 1) q \|= 01;
404			if (my >= (y0 + y1) >> 1) q \|= 02;
405	gregl	3.11	tp->flgs = CH_ANY\|LFF(q); /* all new */
406	gregl	3.5	tp->k[q].li = lo;
407	gregl	3.1	}
408	gregl	3.10	return(1); /* done */
409	gregl	3.1	}
410
411
412	gregl	3.10	dev_value(c, p, v) /* add a pixel value to our quadtree */
413	gregl	3.1	COLR c;
414	gregl	3.10	FVECT p, v;
415	gregl	3.1	{
416	gregl	3.5	register int li;
417	gregl	3.1
418	gregl	3.5	li = newleaf();
419			VCOPY(qtL.wp[li], p);
420	gregl	3.11	qtL.wd[li] = encodedir(v);
421	gregl	3.5	tmCvColrs(&qtL.brt[li], qtL.chr[li], c, 1);
422	gregl	3.10	if (!addleaf(li))
423			ungetleaf(li);
424	gregl	3.1	}
425
426
427			qtReplant() /* replant our tree using new view */
428			{
429			register int i;
430	gregl	3.5	/* anything to replant? */
431			if (qtL.bl == qtL.tl)
432	gregl	3.1	return;
433	gregl	3.5	qtFreeTree(0); /* blow the old tree away */
434			/* regrow it in new place */
435			for (i = qtL.bl; i != qtL.tl; ) {
436			addleaf(i);
437			if (++i >= qtL.nl) i = 0;
438	gregl	3.1	}
439			}
440
441
442	gregl	3.5	qtMapLeaves(redo) /* map our leaves to RGB */
443			int redo;
444			{
445			int aorg, alen, borg, blen;
446	gregl	3.6	/* recompute mapping? */
447			if (redo)
448			qtL.tml = qtL.bl;
449	gregl	3.5	/* already done? */
450			if (qtL.tml == qtL.tl)
451			return(1);
452			/* compute segments */
453			aorg = qtL.tml;
454			if (qtL.tl >= aorg) {
455			alen = qtL.tl - aorg;
456			blen = 0;
457			} else {
458			alen = qtL.nl - aorg;
459			borg = 0;
460			blen = qtL.tl;
461			}
462			/* (re)compute tone mapping? */
463			if (qtL.tml == qtL.bl) {
464			tmClearHisto();
465			tmAddHisto(qtL.brt+aorg, alen, 1);
466			if (blen > 0)
467			tmAddHisto(qtL.brt+borg, blen, 1);
468			if (tmComputeMapping(0., 0., 0.) != TM_E_OK)
469			return(0);
470			}
471			if (tmMapPixels(qtL.rgb+aorg, qtL.brt+aorg,
472			qtL.chr+aorg, alen) != TM_E_OK)
473			return(0);
474			if (blen > 0)
475			tmMapPixels(qtL.rgb+borg, qtL.brt+borg,
476			qtL.chr+borg, blen);
477			qtL.tml = qtL.tl;
478			return(1);
479	gregl	3.1	}