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

RTREE   qtrunk;                 /* our quadtree trunk */
double  qtDepthEps = .02;       /* 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 is_stump(t)     (!((t)->flgs & (BR_ANY|LF_ANY)))


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;
        nexttwig = 0;
        if (twigbundle == NULL)
                return;
        if (!really) {          /* just clear allocated blocks */
                for (i = 0; twigbundle[i] != NULL; 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(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.brt = (TMbright *)(qtL.wp + 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);
}


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;
        int     x, y, mx, my;
        double  z;
        FVECT   ip, wp;
        register int    q;
                                        /* compute leaf location */
        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;
        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;
                }       
                                                /* check existing leaf */
                if (lo != tp->k[q].li) {
                        lo = tp->k[q].li;
                        VCOPY(wp, qtL.wp[lo]);
                        viewloc(ip, &odev.v, wp);
                }
                                                /* is node minimum size? */
                if (x1-x0 <= qtMinNodesiz || y1-y0 <= qtMinNodesiz) {
                        if (z > (1.-qtDepthEps)*ip[2])  /* who is closer? */
                                return;                 /* old one is */
                        tp->k[q].li = li;               /* 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->k[q].li = lo;
                tp->flgs |= LFF(q)|CH_ANY;      /* all new */
        }
}


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

        li = newleaf();
        VCOPY(qtL.wp[li], p);
        tmCvColrs(&qtL.brt[li], qtL.chr[li], c, 1);
        addleaf(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);
}


static
redraw(ca, tp, x0, y0, x1, y1, l)       /* redraw portion of a tree */
BYTE    ca[3];          /* returned average color */
register RTREE  *tp;
int     x0, y0, x1, y1;
int     l[2][2];
{
        int     csm[3], nc;
        register BYTE   *cp;
        BYTE    rgb[3];
        int     quads = CH_ANY;
        int     mx, my;
        register int    i;
                                        /* compute midpoint */
        mx = (x0 + x1) >> 1;
        my = (y0 + y1) >> 1;
                                        /* see what to do */
        if (l[0][0] >= mx)
                quads &= ~(CHF(2)|CHF(0));
        else if (l[0][1] <= mx)
                quads &= ~(CHF(3)|CHF(1));
        if (l[1][0] >= my)
                quads &= ~(CHF(1)|CHF(0));
        else if (l[1][1] <= my)
                quads &= ~(CHF(3)|CHF(2));
        tp->flgs &= ~quads;             /* mark them done */
        csm[0] = csm[1] = csm[2] = nc = 0;
                                        /* do leaves first */
        for (i = 0; i < 4; i++)
                if (quads & CHF(i) && tp->flgs & LFF(i)) {
                        dev_paintr(cp=qtL.rgb[tp->k[i].li],
                                        i&01 ? mx : x0, i&02 ? my : y0,
                                        i&01 ? x1 : mx, i&02 ? y1 : my);
                        csm[0] += cp[0]; csm[1] += cp[1]; csm[2] += cp[2];
                        nc++;
                        quads &= ~CHF(i);
                }
                                        /* now do branches */
        for (i = 0; i < 4; i++)
                if (quads & CHF(i) && tp->flgs & BRF(i)) {
                        redraw(rgb, tp->k[i].b, i&01 ? mx : x0, i&02 ? my : y0,
                                        i&01 ? x1 : mx, i&02 ? y1 : my, l);
                        csm[0] += rgb[0]; csm[1] += rgb[1]; csm[2] += rgb[2];
                        nc++;
                        quads &= ~CHF(i);
                }
        if (nc > 1) {
                ca[0] = csm[0]/nc; ca[1] = csm[1]/nc; ca[2] = csm[2]/nc;
        } else {
                ca[0] = csm[0]; ca[1] = csm[1]; ca[2] = csm[2];
        }
        if (!quads) return;
                                        /* fill in gaps with average */
        for (i = 0; i < 4; i++)
                if (quads & CHF(i))
                        dev_paintr(ca, i&01 ? mx : x0, i&02 ? my : y0,
                                        i&01 ? x1 : mx, i&02 ? y1 : my);
}


static
update(ca, tp, x0, y0, x1, y1)  /* update tree display as needed */
BYTE    ca[3];          /* returned average color */
register RTREE  *tp;
int     x0, y0, x1, y1;
{
        int     csm[3], nc;
        register BYTE   *cp;
        BYTE    rgb[3];
        int     gaps = 0;
        int     mx, my;
        register int    i;
                                        /* compute midpoint */
        mx = (x0 + x1) >> 1;
        my = (y0 + y1) >> 1;
        csm[0] = csm[1] = csm[2] = nc = 0;
                                        /* do leaves first */
        for (i = 0; i < 4; i++) {
                if (!(tp->flgs & CHF(i)))
                        continue;
                if (tp->flgs & LFF(i)) {
                        dev_paintr(cp=qtL.rgb[tp->k[i].li],
                                        i&01 ? mx : x0, i&02 ? my : y0,
                                        i&01 ? x1 : mx, i&02 ? y1 : my);
                        csm[0] += cp[0]; csm[1] += cp[1]; csm[2] += cp[2];
                        nc++;
                } else if (!(tp->flgs & BRF(i)))
                        gaps |= 1<<i;   /* empty stem */
        }
                                        /* now do branches */
        for (i = 0; i < 4; i++)
                if ((tp->flgs & CHBRF(i)) == CHBRF(i)) {
                        update(rgb, tp->k[i].b, i&01 ? mx : x0, i&02 ? my : y0,
                                        i&01 ? x1 : mx, i&02 ? y1 : my);
                        csm[0] += rgb[0]; csm[1] += rgb[1]; csm[2] += rgb[2];
                        nc++;
                }
        if (nc > 1) {
                ca[0] = csm[0]/nc; ca[1] = csm[1]/nc; ca[2] = csm[2]/nc;
        } else {
                ca[0] = csm[0]; ca[1] = csm[1]; ca[2] = csm[2];
        }
                                        /* fill in gaps with average */
        for (i = 0; gaps && i < 4; gaps >>= 1, i++)
                if (gaps & 01)
                        dev_paintr(ca, i&01 ? mx : x0, i&02 ? my : y0,
                                        i&01 ? x1 : mx, i&02 ? y1 : my);
        tp->flgs &= ~CH_ANY;            /* all done */
}


qtRedraw(x0, y0, x1, y1)        /* redraw part or all of our screen */
int     x0, y0, x1, y1;
{
        int     lim[2][2];
        BYTE    ca[3];

        if (is_stump(&qtrunk))
                return;
        if (!qtMapLeaves((lim[0][0]=x0) <= 0 & (lim[1][0]=y0) <= 0 &
                (lim[0][1]=x1) >= odev.hres-1 & (lim[1][1]=y1) >= odev.vres-1))
                return;
        redraw(ca, &qtrunk, 0, 0, odev.hres, odev.vres, lim);
}


qtUpdate()                      /* update our tree display */
{
        BYTE    ca[3];

        if (is_stump(&qtrunk))
                return;
        if (!qtMapLeaves(0))
                return;
        update(ca, &qtrunk, 0, 0, odev.hres, odev.vres);
}
Revision:	3.6
Committed:	Mon Nov 24 15:16:10 1997 UTC (26 years, 5 months ago) by gregl
Content type:	text/plain
Branch:	MAIN
Changes since 3.5:	+8 -3 lines
Log Message:	moved LFREEPCT to rhd_qtree.c and changed from 15% to 25% fixed bug in trunk flag settings in qtFreeTree() fixed bug in tone remapping routine
#	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	3.1
18	gregl	3.2	RTREE qtrunk; /* our quadtree trunk */
19			double qtDepthEps = .02; /* epsilon to compare depths (z fraction) */
20			int qtMinNodesiz = 2; /* minimum node dimension (pixels) */
21	gregl	3.5	struct rleaves qtL; /* our pile of leaves */
22	gregl	3.2
23	gregl	3.1	#define TBUNDLESIZ 409 /* number of twigs in a bundle */
24
25			static RTREE *twigbundle; / free twig blocks (NULL term.) */
26			static int nexttwig; /* next free twig */
27
28	gregl	3.5	#define is_stump(t) (!((t)->flgs & (BR_ANY\|LF_ANY)))
29	gregl	3.1
30
31			static RTREE *
32			newtwig() /* allocate a twig */
33			{
34			register int bi;
35
36			if (twigbundle == NULL) { /* initialize */
37			twigbundle = (RTREE *)malloc(sizeof(RTREE ));
38			if (twigbundle == NULL)
39			goto memerr;
40			twigbundle[0] = NULL;
41			}
42			bi = nexttwig / TBUNDLESIZ;
43			if (twigbundle[bi] == NULL) { /* new block */
44			twigbundle = (RTREE *)realloc((char )twigbundle,
45			(bi+2)sizeof(RTREE ));
46			if (twigbundle == NULL)
47			goto memerr;
48			twigbundle[bi] = (RTREE *)calloc(TBUNDLESIZ, sizeof(RTREE));
49			if (twigbundle[bi] == NULL)
50			goto memerr;
51			twigbundle[bi+1] = NULL;
52			}
53			/* nexttwig++ % TBUNDLESIZ */
54			return(twigbundle[bi] + (nexttwig++ - bi*TBUNDLESIZ));
55			memerr:
56			error(SYSTEM, "out of memory in newtwig");
57			}
58
59
60	gregl	3.3	qtFreeTree(really) /* free allocated twigs */
61	gregl	3.1	int really;
62			{
63			register int i;
64
65	gregl	3.6	qtrunk.flgs = CH_ANY;
66	gregl	3.1	nexttwig = 0;
67			if (twigbundle == NULL)
68			return;
69			if (!really) { /* just clear allocated blocks */
70			for (i = 0; twigbundle[i] != NULL; i++)
71			bzero((char )twigbundle[i], TBUNDLESIZsizeof(RTREE));
72			return;
73			}
74			/* else "really" means free up memory */
75			for (i = 0; twigbundle[i] != NULL; i++)
76			free((char *)twigbundle[i]);
77			free((char *)twigbundle);
78			twigbundle = NULL;
79			}
80
81
82	gregl	3.5	static int
83	gregl	3.1	newleaf() /* allocate a leaf from our pile */
84			{
85	gregl	3.5	int li;
86	gregl	3.4
87	gregl	3.5	li = qtL.tl++;
88			if (qtL.tl >= qtL.nl) /* get next leaf in ring */
89			qtL.tl = 0;
90			if (qtL.tl == qtL.bl) /* need to shake some free */
91	gregl	3.1	qtCompost(LFREEPCT);
92	gregl	3.5	return(li);
93	gregl	3.1	}
94
95
96	gregl	3.5	#define LEAFSIZ (3sizeof(float)+sizeof(TMbright)+6sizeof(BYTE))
97
98	gregl	3.1	int
99			qtAllocLeaves(n) /* allocate space for n leaves */
100	gregl	3.5	register int n;
101	gregl	3.1	{
102			unsigned nbytes;
103			register unsigned i;
104
105	gregl	3.3	qtFreeTree(0); /* make sure tree is empty */
106	gregl	3.1	if (n <= 0)
107			return(0);
108	gregl	3.5	if (qtL.nl >= n)
109			return(qtL.nl);
110			else if (qtL.nl > 0)
111			free(qtL.base);
112	gregl	3.1	/* round space up to nearest power of 2 */
113	gregl	3.5	nbytes = n*LEAFSIZ + 8;
114	gregl	3.1	for (i = 1024; nbytes > i; i <<= 1)
115			;
116	gregl	3.5	n = (i - 8) / LEAFSIZ; /* should we make sure n is even? */
117			qtL.base = (char )malloc(nLEAFSIZ);
118			if (qtL.base == NULL)
119			return(0);
120			/* assign larger alignment types earlier */
121			qtL.wp = (float (*)[3])qtL.base;
122			qtL.brt = (TMbright *)(qtL.wp + n);
123			qtL.chr = (BYTE (*)[3])(qtL.brt + n);
124			qtL.rgb = (BYTE (*)[3])(qtL.chr + n);
125			qtL.nl = n;
126			qtL.tml = qtL.bl = qtL.tl = 0;
127			return(n);
128	gregl	3.1	}
129
130	gregl	3.5	#undef LEAFSIZ
131	gregl	3.1
132	gregl	3.5
133	gregl	3.1	qtFreeLeaves() /* free our allocated leaves and twigs */
134			{
135	gregl	3.3	qtFreeTree(1); /* free tree also */
136	gregl	3.5	if (qtL.nl <= 0)
137	gregl	3.1	return;
138	gregl	3.5	free(qtL.base);
139			qtL.base = NULL;
140			qtL.nl = 0;
141	gregl	3.1	}
142
143
144			static
145			shaketree(tp) /* shake dead leaves from tree */
146			register RTREE *tp;
147			{
148			register int i, li;
149
150			for (i = 0; i < 4; i++)
151	gregl	3.5	if (tp->flgs & BRF(i)) {
152	gregl	3.2	shaketree(tp->k[i].b);
153	gregl	3.5	if (is_stump(tp->k[i].b))
154			tp->flgs &= ~BRF(i);
155			} else if (tp->flgs & LFF(i)) {
156			li = tp->k[i].li;
157			if (qtL.bl < qtL.tl ?
158			(li < qtL.bl \|\| li >= qtL.tl) :
159			(li < qtL.bl && li >= qtL.tl))
160			tp->flgs &= ~LFF(i);
161	gregl	3.1	}
162			}
163
164
165			int
166			qtCompost(pct) /* free up some leaves */
167			int pct;
168			{
169	gregl	3.5	int nused, nclear, nmapped;
170	gregl	3.4
171	gregl	3.1	/* figure out how many leaves to clear */
172	gregl	3.5	nclear = qtL.nl * pct / 100;
173			nused = qtL.tl - qtL.bl;
174			if (nused <= 0) nused += qtL.nl;
175			nclear -= qtL.nl - nused;
176	gregl	3.1	if (nclear <= 0)
177			return(0);
178			if (nclear >= nused) { /* clear them all */
179	gregl	3.3	qtFreeTree(0);
180	gregl	3.5	qtL.tml = qtL.bl = qtL.tl = 0;
181	gregl	3.1	return(nused);
182			}
183			/* else clear leaves from bottom */
184	gregl	3.5	nmapped = qtL.tml - qtL.bl;
185			if (nmapped < 0) nmapped += qtL.nl;
186			qtL.bl += nclear;
187			if (qtL.bl >= qtL.nl) qtL.bl -= qtL.nl;
188			if (nmapped <= nclear) qtL.tml = qtL.bl;
189	gregl	3.1	shaketree(&qtrunk);
190			return(nclear);
191			}
192
193
194	gregl	3.5	int
195	gregl	3.3	qtFindLeaf(x, y) /* find closest leaf to (x,y) */
196			int x, y;
197			{
198			register RTREE *tp = &qtrunk;
199	gregl	3.5	int li = -1;
200	gregl	3.3	int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
201			int mx, my;
202			register int q;
203			/* check limits */
204			if (x < 0 \|\| x >= odev.hres \|\| y < 0 \|\| y >= odev.vres)
205	gregl	3.5	return(-1);
206	gregl	3.3	/* find nearby leaf in our tree */
207			for ( ; ; ) {
208			for (q = 0; q < 4; q++) /* find any leaf this level */
209	gregl	3.5	if (tp->flgs & LFF(q)) {
210			li = tp->k[q].li;
211	gregl	3.3	break;
212			}
213			q = 0; /* which quadrant are we? */
214			mx = (x0 + x1) >> 1;
215			my = (y0 + y1) >> 1;
216			if (x < mx) x1 = mx;
217			else {x0 = mx; q \|= 01;}
218			if (y < my) y1 = my;
219			else {y0 = my; q \|= 02;}
220			if (tp->flgs & BRF(q)) { /* branch down if not a leaf */
221			tp = tp->k[q].b;
222			continue;
223			}
224	gregl	3.5	if (tp->flgs & LFF(q)) /* good shot! */
225			return(tp->k[q].li);
226			return(li); /* else return what we have */
227	gregl	3.3	}
228			}
229
230
231	gregl	3.1	static
232	gregl	3.5	addleaf(li) /* add a leaf to our tree */
233			int li;
234	gregl	3.1	{
235			register RTREE *tp = &qtrunk;
236			int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
237	gregl	3.5	int lo = -1;
238	gregl	3.1	int x, y, mx, my;
239			double z;
240			FVECT ip, wp;
241			register int q;
242			/* compute leaf location */
243	gregl	3.5	VCOPY(wp, qtL.wp[li]);
244	gregl	3.1	viewloc(ip, &odev.v, wp);
245			if (ip[2] <= 0. \|\| ip[0] < 0. \|\| ip[0] >= 1.
246			\|\| ip[1] < 0. \|\| ip[1] >= 1.)
247			return;
248			x = ip[0] * odev.hres;
249			y = ip[1] * odev.vres;
250			z = ip[2];
251			/* find the place for it */
252			for ( ; ; ) {
253			q = 0; /* which quadrant? */
254			mx = (x0 + x1) >> 1;
255			my = (y0 + y1) >> 1;
256			if (x < mx) x1 = mx;
257			else {x0 = mx; q \|= 01;}
258			if (y < my) y1 = my;
259			else {y0 = my; q \|= 02;}
260			if (tp->flgs & BRF(q)) { /* move to next branch */
261			tp->flgs \|= CHF(q); /* not sure; guess */
262			tp = tp->k[q].b;
263			continue;
264			}
265	gregl	3.5	if (!(tp->flgs & LFF(q))) { /* found stem for leaf */
266			tp->k[q].li = li;
267			tp->flgs \|= CHLFF(q);
268	gregl	3.1	break;
269			}
270			/* check existing leaf */
271	gregl	3.5	if (lo != tp->k[q].li) {
272			lo = tp->k[q].li;
273			VCOPY(wp, qtL.wp[lo]);
274	gregl	3.1	viewloc(ip, &odev.v, wp);
275			}
276			/* is node minimum size? */
277			if (x1-x0 <= qtMinNodesiz \|\| y1-y0 <= qtMinNodesiz) {
278			if (z > (1.-qtDepthEps)ip[2]) / who is closer? */
279			return; /* old one is */
280	gregl	3.5	tp->k[q].li = li; /* new one is */
281	gregl	3.1	tp->flgs \|= CHF(q);
282			break;
283			}
284	gregl	3.5	tp->flgs &= ~LFF(q); /* else grow tree */
285			tp->flgs \|= CHBRF(q);
286	gregl	3.1	tp = tp->k[q].b = newtwig();
287			q = 0; /* old leaf -> new branch */
288			mx = ip[0] * odev.hres;
289			my = ip[1] * odev.vres;
290			if (mx >= (x0 + x1) >> 1) q \|= 01;
291			if (my >= (y0 + y1) >> 1) q \|= 02;
292	gregl	3.5	tp->k[q].li = lo;
293			tp->flgs \|= LFF(q)\|CH_ANY; /* all new */
294	gregl	3.1	}
295			}
296
297
298			dev_value(c, p) /* add a pixel value to our output queue */
299			COLR c;
300			FVECT p;
301			{
302	gregl	3.5	register int li;
303	gregl	3.1
304	gregl	3.5	li = newleaf();
305			VCOPY(qtL.wp[li], p);
306			tmCvColrs(&qtL.brt[li], qtL.chr[li], c, 1);
307			addleaf(li);
308	gregl	3.1	}
309
310
311			qtReplant() /* replant our tree using new view */
312			{
313			register int i;
314	gregl	3.5	/* anything to replant? */
315			if (qtL.bl == qtL.tl)
316	gregl	3.1	return;
317	gregl	3.5	qtFreeTree(0); /* blow the old tree away */
318			/* regrow it in new place */
319			for (i = qtL.bl; i != qtL.tl; ) {
320			addleaf(i);
321			if (++i >= qtL.nl) i = 0;
322	gregl	3.1	}
323			}
324
325
326	gregl	3.5	qtMapLeaves(redo) /* map our leaves to RGB */
327			int redo;
328			{
329			int aorg, alen, borg, blen;
330	gregl	3.6	/* recompute mapping? */
331			if (redo)
332			qtL.tml = qtL.bl;
333	gregl	3.5	/* already done? */
334			if (qtL.tml == qtL.tl)
335			return(1);
336			/* compute segments */
337			aorg = qtL.tml;
338			if (qtL.tl >= aorg) {
339			alen = qtL.tl - aorg;
340			blen = 0;
341			} else {
342			alen = qtL.nl - aorg;
343			borg = 0;
344			blen = qtL.tl;
345			}
346			/* (re)compute tone mapping? */
347			if (qtL.tml == qtL.bl) {
348			tmClearHisto();
349			tmAddHisto(qtL.brt+aorg, alen, 1);
350			if (blen > 0)
351			tmAddHisto(qtL.brt+borg, blen, 1);
352			if (tmComputeMapping(0., 0., 0.) != TM_E_OK)
353			return(0);
354			}
355			if (tmMapPixels(qtL.rgb+aorg, qtL.brt+aorg,
356			qtL.chr+aorg, alen) != TM_E_OK)
357			return(0);
358			if (blen > 0)
359			tmMapPixels(qtL.rgb+borg, qtL.brt+borg,
360			qtL.chr+borg, blen);
361			qtL.tml = qtL.tl;
362			return(1);
363			}
364
365
366	gregl	3.1	static
367			redraw(ca, tp, x0, y0, x1, y1, l) /* redraw portion of a tree */
368			BYTE ca[3]; /* returned average color */
369			register RTREE *tp;
370			int x0, y0, x1, y1;
371			int l[2][2];
372			{
373			int csm[3], nc;
374	gregl	3.5	register BYTE *cp;
375	gregl	3.1	BYTE rgb[3];
376			int quads = CH_ANY;
377			int mx, my;
378			register int i;
379			/* compute midpoint */
380			mx = (x0 + x1) >> 1;
381			my = (y0 + y1) >> 1;
382			/* see what to do */
383			if (l[0][0] >= mx)
384			quads &= ~(CHF(2)\|CHF(0));
385			else if (l[0][1] <= mx)
386			quads &= ~(CHF(3)\|CHF(1));
387			if (l[1][0] >= my)
388			quads &= ~(CHF(1)\|CHF(0));
389			else if (l[1][1] <= my)
390			quads &= ~(CHF(3)\|CHF(2));
391			tp->flgs &= ~quads; /* mark them done */
392			csm[0] = csm[1] = csm[2] = nc = 0;
393			/* do leaves first */
394			for (i = 0; i < 4; i++)
395	gregl	3.5	if (quads & CHF(i) && tp->flgs & LFF(i)) {
396			dev_paintr(cp=qtL.rgb[tp->k[i].li],
397			i&01 ? mx : x0, i&02 ? my : y0,
398	gregl	3.1	i&01 ? x1 : mx, i&02 ? y1 : my);
399	gregl	3.5	csm[0] += cp[0]; csm[1] += cp[1]; csm[2] += cp[2];
400	gregl	3.1	nc++;
401			quads &= ~CHF(i);
402			}
403			/* now do branches */
404			for (i = 0; i < 4; i++)
405			if (quads & CHF(i) && tp->flgs & BRF(i)) {
406			redraw(rgb, tp->k[i].b, i&01 ? mx : x0, i&02 ? my : y0,
407			i&01 ? x1 : mx, i&02 ? y1 : my, l);
408			csm[0] += rgb[0]; csm[1] += rgb[1]; csm[2] += rgb[2];
409			nc++;
410			quads &= ~CHF(i);
411			}
412			if (nc > 1) {
413			ca[0] = csm[0]/nc; ca[1] = csm[1]/nc; ca[2] = csm[2]/nc;
414			} else {
415			ca[0] = csm[0]; ca[1] = csm[1]; ca[2] = csm[2];
416			}
417			if (!quads) return;
418			/* fill in gaps with average */
419			for (i = 0; i < 4; i++)
420			if (quads & CHF(i))
421			dev_paintr(ca, i&01 ? mx : x0, i&02 ? my : y0,
422			i&01 ? x1 : mx, i&02 ? y1 : my);
423			}
424
425
426			static
427			update(ca, tp, x0, y0, x1, y1) /* update tree display as needed */
428			BYTE ca[3]; /* returned average color */
429			register RTREE *tp;
430			int x0, y0, x1, y1;
431			{
432			int csm[3], nc;
433	gregl	3.5	register BYTE *cp;
434	gregl	3.1	BYTE rgb[3];
435			int gaps = 0;
436			int mx, my;
437			register int i;
438			/* compute midpoint */
439			mx = (x0 + x1) >> 1;
440			my = (y0 + y1) >> 1;
441			csm[0] = csm[1] = csm[2] = nc = 0;
442			/* do leaves first */
443	gregl	3.5	for (i = 0; i < 4; i++) {
444			if (!(tp->flgs & CHF(i)))
445			continue;
446			if (tp->flgs & LFF(i)) {
447			dev_paintr(cp=qtL.rgb[tp->k[i].li],
448			i&01 ? mx : x0, i&02 ? my : y0,
449	gregl	3.1	i&01 ? x1 : mx, i&02 ? y1 : my);
450	gregl	3.5	csm[0] += cp[0]; csm[1] += cp[1]; csm[2] += cp[2];
451	gregl	3.1	nc++;
452	gregl	3.5	} else if (!(tp->flgs & BRF(i)))
453			gaps \|= 1<<i; /* empty stem */
454			}
455	gregl	3.1	/* now do branches */
456			for (i = 0; i < 4; i++)
457			if ((tp->flgs & CHBRF(i)) == CHBRF(i)) {
458			update(rgb, tp->k[i].b, i&01 ? mx : x0, i&02 ? my : y0,
459			i&01 ? x1 : mx, i&02 ? y1 : my);
460			csm[0] += rgb[0]; csm[1] += rgb[1]; csm[2] += rgb[2];
461			nc++;
462			}
463			if (nc > 1) {
464			ca[0] = csm[0]/nc; ca[1] = csm[1]/nc; ca[2] = csm[2]/nc;
465			} else {
466			ca[0] = csm[0]; ca[1] = csm[1]; ca[2] = csm[2];
467			}
468			/* fill in gaps with average */
469			for (i = 0; gaps && i < 4; gaps >>= 1, i++)
470			if (gaps & 01)
471			dev_paintr(ca, i&01 ? mx : x0, i&02 ? my : y0,
472			i&01 ? x1 : mx, i&02 ? y1 : my);
473			tp->flgs &= ~CH_ANY; /* all done */
474			}
475
476
477	gregl	3.5	qtRedraw(x0, y0, x1, y1) /* redraw part or all of our screen */
478	gregl	3.1	int x0, y0, x1, y1;
479			{
480			int lim[2][2];
481			BYTE ca[3];
482
483			if (is_stump(&qtrunk))
484			return;
485	gregl	3.5	if (!qtMapLeaves((lim[0][0]=x0) <= 0 & (lim[1][0]=y0) <= 0 &
486			(lim[0][1]=x1) >= odev.hres-1 & (lim[1][1]=y1) >= odev.vres-1))
487			return;
488	gregl	3.1	redraw(ca, &qtrunk, 0, 0, odev.hres, odev.vres, lim);
489			}
490
491
492			qtUpdate() /* update our tree display */
493			{
494			BYTE ca[3];
495
496			if (is_stump(&qtrunk))
497			return;
498	gregl	3.5	if (!qtMapLeaves(0))
499			return;
500	gregl	3.1	update(ca, &qtrunk, 0, 0, odev.hres, odev.vres);
501			}