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;   /* 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(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(tp, x0, y0, x1, y1, l)   /* mark portion of a tree for redraw */
register RTREE  *tp;
int     x0, y0, x1, y1;
int     l[2][2];
{
        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 quadrants for update */
                                        /* climb the branches */
        for (i = 0; i < 4; i++)
                if (tp->flgs & BRF(i) && quads & CHF(i))
                        redraw(tp->k[i].b, i&01 ? mx : x0, i&02 ? my : y0,
                                        i&01 ? x1 : mx, i&02 ? y1 : my, l);
}


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];

        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(&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:	3.7
Committed:	Tue Nov 25 11:15:20 1997 UTC (26 years, 10 months ago) by gregl
Content type:	text/plain
Branch:	MAIN
Changes since 3.6:	+12 -42 lines
Log Message:	changed redraw function to simply mark branches and leaves for update
#	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	3.7	qtrunk.flgs = CH_ANY; /* chop down tree */
66	gregl	3.1	if (twigbundle == NULL)
67			return;
68	gregl	3.7	i = (TBUNDLESIZ-1+nexttwig)/TBUNDLESIZ;
69			nexttwig = 0;
70	gregl	3.1	if (!really) { /* just clear allocated blocks */
71	gregl	3.7	while (i--)
72	gregl	3.1	bzero((char )twigbundle[i], TBUNDLESIZsizeof(RTREE));
73			return;
74			}
75			/* else "really" means free up memory */
76			for (i = 0; twigbundle[i] != NULL; i++)
77			free((char *)twigbundle[i]);
78			free((char *)twigbundle);
79			twigbundle = NULL;
80			}
81
82
83	gregl	3.5	static int
84	gregl	3.1	newleaf() /* allocate a leaf from our pile */
85			{
86	gregl	3.5	int li;
87	gregl	3.4
88	gregl	3.5	li = qtL.tl++;
89			if (qtL.tl >= qtL.nl) /* get next leaf in ring */
90			qtL.tl = 0;
91			if (qtL.tl == qtL.bl) /* need to shake some free */
92	gregl	3.1	qtCompost(LFREEPCT);
93	gregl	3.5	return(li);
94	gregl	3.1	}
95
96
97	gregl	3.5	#define LEAFSIZ (3sizeof(float)+sizeof(TMbright)+6sizeof(BYTE))
98
99	gregl	3.1	int
100			qtAllocLeaves(n) /* allocate space for n leaves */
101	gregl	3.5	register int n;
102	gregl	3.1	{
103			unsigned nbytes;
104			register unsigned i;
105
106	gregl	3.3	qtFreeTree(0); /* make sure tree is empty */
107	gregl	3.1	if (n <= 0)
108			return(0);
109	gregl	3.5	if (qtL.nl >= n)
110			return(qtL.nl);
111			else if (qtL.nl > 0)
112			free(qtL.base);
113	gregl	3.1	/* round space up to nearest power of 2 */
114	gregl	3.5	nbytes = n*LEAFSIZ + 8;
115	gregl	3.1	for (i = 1024; nbytes > i; i <<= 1)
116			;
117	gregl	3.5	n = (i - 8) / LEAFSIZ; /* should we make sure n is even? */
118			qtL.base = (char )malloc(nLEAFSIZ);
119			if (qtL.base == NULL)
120			return(0);
121			/* assign larger alignment types earlier */
122			qtL.wp = (float (*)[3])qtL.base;
123			qtL.brt = (TMbright *)(qtL.wp + n);
124			qtL.chr = (BYTE (*)[3])(qtL.brt + n);
125			qtL.rgb = (BYTE (*)[3])(qtL.chr + n);
126			qtL.nl = n;
127			qtL.tml = qtL.bl = qtL.tl = 0;
128			return(n);
129	gregl	3.1	}
130
131	gregl	3.5	#undef LEAFSIZ
132	gregl	3.1
133	gregl	3.5
134	gregl	3.1	qtFreeLeaves() /* free our allocated leaves and twigs */
135			{
136	gregl	3.3	qtFreeTree(1); /* free tree also */
137	gregl	3.5	if (qtL.nl <= 0)
138	gregl	3.1	return;
139	gregl	3.5	free(qtL.base);
140			qtL.base = NULL;
141			qtL.nl = 0;
142	gregl	3.1	}
143
144
145			static
146			shaketree(tp) /* shake dead leaves from tree */
147			register RTREE *tp;
148			{
149			register int i, li;
150
151			for (i = 0; i < 4; i++)
152	gregl	3.5	if (tp->flgs & BRF(i)) {
153	gregl	3.2	shaketree(tp->k[i].b);
154	gregl	3.5	if (is_stump(tp->k[i].b))
155			tp->flgs &= ~BRF(i);
156			} else if (tp->flgs & LFF(i)) {
157			li = tp->k[i].li;
158			if (qtL.bl < qtL.tl ?
159			(li < qtL.bl \|\| li >= qtL.tl) :
160			(li < qtL.bl && li >= qtL.tl))
161			tp->flgs &= ~LFF(i);
162	gregl	3.1	}
163			}
164
165
166			int
167			qtCompost(pct) /* free up some leaves */
168			int pct;
169			{
170	gregl	3.5	int nused, nclear, nmapped;
171	gregl	3.4
172	gregl	3.1	/* figure out how many leaves to clear */
173	gregl	3.5	nclear = qtL.nl * pct / 100;
174			nused = qtL.tl - qtL.bl;
175			if (nused <= 0) nused += qtL.nl;
176			nclear -= qtL.nl - nused;
177	gregl	3.1	if (nclear <= 0)
178			return(0);
179			if (nclear >= nused) { /* clear them all */
180	gregl	3.3	qtFreeTree(0);
181	gregl	3.5	qtL.tml = qtL.bl = qtL.tl = 0;
182	gregl	3.1	return(nused);
183			}
184			/* else clear leaves from bottom */
185	gregl	3.5	nmapped = qtL.tml - qtL.bl;
186			if (nmapped < 0) nmapped += qtL.nl;
187			qtL.bl += nclear;
188			if (qtL.bl >= qtL.nl) qtL.bl -= qtL.nl;
189			if (nmapped <= nclear) qtL.tml = qtL.bl;
190	gregl	3.1	shaketree(&qtrunk);
191			return(nclear);
192			}
193
194
195	gregl	3.5	int
196	gregl	3.3	qtFindLeaf(x, y) /* find closest leaf to (x,y) */
197			int x, y;
198			{
199			register RTREE *tp = &qtrunk;
200	gregl	3.5	int li = -1;
201	gregl	3.3	int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
202			int mx, my;
203			register int q;
204			/* check limits */
205			if (x < 0 \|\| x >= odev.hres \|\| y < 0 \|\| y >= odev.vres)
206	gregl	3.5	return(-1);
207	gregl	3.3	/* find nearby leaf in our tree */
208			for ( ; ; ) {
209			for (q = 0; q < 4; q++) /* find any leaf this level */
210	gregl	3.5	if (tp->flgs & LFF(q)) {
211			li = tp->k[q].li;
212	gregl	3.3	break;
213			}
214			q = 0; /* which quadrant are we? */
215			mx = (x0 + x1) >> 1;
216			my = (y0 + y1) >> 1;
217			if (x < mx) x1 = mx;
218			else {x0 = mx; q \|= 01;}
219			if (y < my) y1 = my;
220			else {y0 = my; q \|= 02;}
221			if (tp->flgs & BRF(q)) { /* branch down if not a leaf */
222			tp = tp->k[q].b;
223			continue;
224			}
225	gregl	3.5	if (tp->flgs & LFF(q)) /* good shot! */
226			return(tp->k[q].li);
227			return(li); /* else return what we have */
228	gregl	3.3	}
229			}
230
231
232	gregl	3.1	static
233	gregl	3.5	addleaf(li) /* add a leaf to our tree */
234			int li;
235	gregl	3.1	{
236			register RTREE *tp = &qtrunk;
237			int x0=0, y0=0, x1=odev.hres, y1=odev.vres;
238	gregl	3.5	int lo = -1;
239	gregl	3.1	int x, y, mx, my;
240			double z;
241			FVECT ip, wp;
242			register int q;
243			/* compute leaf location */
244	gregl	3.5	VCOPY(wp, qtL.wp[li]);
245	gregl	3.1	viewloc(ip, &odev.v, wp);
246			if (ip[2] <= 0. \|\| ip[0] < 0. \|\| ip[0] >= 1.
247			\|\| ip[1] < 0. \|\| ip[1] >= 1.)
248			return;
249			x = ip[0] * odev.hres;
250			y = ip[1] * odev.vres;
251			z = ip[2];
252			/* find the place for it */
253			for ( ; ; ) {
254			q = 0; /* which quadrant? */
255			mx = (x0 + x1) >> 1;
256			my = (y0 + y1) >> 1;
257			if (x < mx) x1 = mx;
258			else {x0 = mx; q \|= 01;}
259			if (y < my) y1 = my;
260			else {y0 = my; q \|= 02;}
261			if (tp->flgs & BRF(q)) { /* move to next branch */
262			tp->flgs \|= CHF(q); /* not sure; guess */
263			tp = tp->k[q].b;
264			continue;
265			}
266	gregl	3.5	if (!(tp->flgs & LFF(q))) { /* found stem for leaf */
267			tp->k[q].li = li;
268			tp->flgs \|= CHLFF(q);
269	gregl	3.1	break;
270			}
271			/* check existing leaf */
272	gregl	3.5	if (lo != tp->k[q].li) {
273			lo = tp->k[q].li;
274			VCOPY(wp, qtL.wp[lo]);
275	gregl	3.1	viewloc(ip, &odev.v, wp);
276			}
277			/* is node minimum size? */
278			if (x1-x0 <= qtMinNodesiz \|\| y1-y0 <= qtMinNodesiz) {
279			if (z > (1.-qtDepthEps)ip[2]) / who is closer? */
280			return; /* old one is */
281	gregl	3.5	tp->k[q].li = li; /* new one is */
282	gregl	3.1	tp->flgs \|= CHF(q);
283			break;
284			}
285	gregl	3.5	tp->flgs &= ~LFF(q); /* else grow tree */
286			tp->flgs \|= CHBRF(q);
287	gregl	3.1	tp = tp->k[q].b = newtwig();
288			q = 0; /* old leaf -> new branch */
289			mx = ip[0] * odev.hres;
290			my = ip[1] * odev.vres;
291			if (mx >= (x0 + x1) >> 1) q \|= 01;
292			if (my >= (y0 + y1) >> 1) q \|= 02;
293	gregl	3.5	tp->k[q].li = lo;
294			tp->flgs \|= LFF(q)\|CH_ANY; /* all new */
295	gregl	3.1	}
296			}
297
298
299			dev_value(c, p) /* add a pixel value to our output queue */
300			COLR c;
301			FVECT p;
302			{
303	gregl	3.5	register int li;
304	gregl	3.1
305	gregl	3.5	li = newleaf();
306			VCOPY(qtL.wp[li], p);
307			tmCvColrs(&qtL.brt[li], qtL.chr[li], c, 1);
308			addleaf(li);
309	gregl	3.1	}
310
311
312			qtReplant() /* replant our tree using new view */
313			{
314			register int i;
315	gregl	3.5	/* anything to replant? */
316			if (qtL.bl == qtL.tl)
317	gregl	3.1	return;
318	gregl	3.5	qtFreeTree(0); /* blow the old tree away */
319			/* regrow it in new place */
320			for (i = qtL.bl; i != qtL.tl; ) {
321			addleaf(i);
322			if (++i >= qtL.nl) i = 0;
323	gregl	3.1	}
324			}
325
326
327	gregl	3.5	qtMapLeaves(redo) /* map our leaves to RGB */
328			int redo;
329			{
330			int aorg, alen, borg, blen;
331	gregl	3.6	/* recompute mapping? */
332			if (redo)
333			qtL.tml = qtL.bl;
334	gregl	3.5	/* already done? */
335			if (qtL.tml == qtL.tl)
336			return(1);
337			/* compute segments */
338			aorg = qtL.tml;
339			if (qtL.tl >= aorg) {
340			alen = qtL.tl - aorg;
341			blen = 0;
342			} else {
343			alen = qtL.nl - aorg;
344			borg = 0;
345			blen = qtL.tl;
346			}
347			/* (re)compute tone mapping? */
348			if (qtL.tml == qtL.bl) {
349			tmClearHisto();
350			tmAddHisto(qtL.brt+aorg, alen, 1);
351			if (blen > 0)
352			tmAddHisto(qtL.brt+borg, blen, 1);
353			if (tmComputeMapping(0., 0., 0.) != TM_E_OK)
354			return(0);
355			}
356			if (tmMapPixels(qtL.rgb+aorg, qtL.brt+aorg,
357			qtL.chr+aorg, alen) != TM_E_OK)
358			return(0);
359			if (blen > 0)
360			tmMapPixels(qtL.rgb+borg, qtL.brt+borg,
361			qtL.chr+borg, blen);
362			qtL.tml = qtL.tl;
363			return(1);
364			}
365
366
367	gregl	3.1	static
368	gregl	3.7	redraw(tp, x0, y0, x1, y1, l) /* mark portion of a tree for redraw */
369	gregl	3.1	register RTREE *tp;
370			int x0, y0, x1, y1;
371			int l[2][2];
372			{
373			int quads = CH_ANY;
374			int mx, my;
375			register int i;
376			/* compute midpoint */
377			mx = (x0 + x1) >> 1;
378			my = (y0 + y1) >> 1;
379			/* see what to do */
380			if (l[0][0] >= mx)
381			quads &= ~(CHF(2)\|CHF(0));
382	gregl	3.7	else if (l[0][1] < mx)
383	gregl	3.1	quads &= ~(CHF(3)\|CHF(1));
384			if (l[1][0] >= my)
385			quads &= ~(CHF(1)\|CHF(0));
386	gregl	3.7	else if (l[1][1] < my)
387	gregl	3.1	quads &= ~(CHF(3)\|CHF(2));
388	gregl	3.7	tp->flgs \|= quads; /* mark quadrants for update */
389			/* climb the branches */
390	gregl	3.1	for (i = 0; i < 4; i++)
391	gregl	3.7	if (tp->flgs & BRF(i) && quads & CHF(i))
392			redraw(tp->k[i].b, i&01 ? mx : x0, i&02 ? my : y0,
393	gregl	3.1	i&01 ? x1 : mx, i&02 ? y1 : my, l);
394			}
395
396
397			static
398			update(ca, tp, x0, y0, x1, y1) /* update tree display as needed */
399			BYTE ca[3]; /* returned average color */
400			register RTREE *tp;
401			int x0, y0, x1, y1;
402			{
403			int csm[3], nc;
404	gregl	3.5	register BYTE *cp;
405	gregl	3.1	BYTE rgb[3];
406			int gaps = 0;
407			int mx, my;
408			register int i;
409			/* compute midpoint */
410			mx = (x0 + x1) >> 1;
411			my = (y0 + y1) >> 1;
412			csm[0] = csm[1] = csm[2] = nc = 0;
413			/* do leaves first */
414	gregl	3.5	for (i = 0; i < 4; i++) {
415			if (!(tp->flgs & CHF(i)))
416			continue;
417			if (tp->flgs & LFF(i)) {
418			dev_paintr(cp=qtL.rgb[tp->k[i].li],
419			i&01 ? mx : x0, i&02 ? my : y0,
420	gregl	3.1	i&01 ? x1 : mx, i&02 ? y1 : my);
421	gregl	3.5	csm[0] += cp[0]; csm[1] += cp[1]; csm[2] += cp[2];
422	gregl	3.1	nc++;
423	gregl	3.5	} else if (!(tp->flgs & BRF(i)))
424			gaps \|= 1<<i; /* empty stem */
425			}
426	gregl	3.1	/* now do branches */
427			for (i = 0; i < 4; i++)
428			if ((tp->flgs & CHBRF(i)) == CHBRF(i)) {
429			update(rgb, tp->k[i].b, i&01 ? mx : x0, i&02 ? my : y0,
430			i&01 ? x1 : mx, i&02 ? y1 : my);
431			csm[0] += rgb[0]; csm[1] += rgb[1]; csm[2] += rgb[2];
432			nc++;
433			}
434			if (nc > 1) {
435			ca[0] = csm[0]/nc; ca[1] = csm[1]/nc; ca[2] = csm[2]/nc;
436			} else {
437			ca[0] = csm[0]; ca[1] = csm[1]; ca[2] = csm[2];
438			}
439			/* fill in gaps with average */
440			for (i = 0; gaps && i < 4; gaps >>= 1, i++)
441			if (gaps & 01)
442			dev_paintr(ca, i&01 ? mx : x0, i&02 ? my : y0,
443			i&01 ? x1 : mx, i&02 ? y1 : my);
444			tp->flgs &= ~CH_ANY; /* all done */
445			}
446
447
448	gregl	3.5	qtRedraw(x0, y0, x1, y1) /* redraw part or all of our screen */
449	gregl	3.1	int x0, y0, x1, y1;
450			{
451			int lim[2][2];
452
453			if (is_stump(&qtrunk))
454			return;
455	gregl	3.5	if (!qtMapLeaves((lim[0][0]=x0) <= 0 & (lim[1][0]=y0) <= 0 &
456			(lim[0][1]=x1) >= odev.hres-1 & (lim[1][1]=y1) >= odev.vres-1))
457			return;
458	gregl	3.7	redraw(&qtrunk, 0, 0, odev.hres, odev.vres, lim);
459	gregl	3.1	}
460
461
462			qtUpdate() /* update our tree display */
463			{
464			BYTE ca[3];
465
466			if (is_stump(&qtrunk))
467			return;
468	gregl	3.5	if (!qtMapLeaves(0))
469			return;
470	gregl	3.1	update(ca, &qtrunk, 0, 0, odev.hres, odev.vres);
471			}