src/util/glareval.c

#ifndef lint
static const char       RCSid[] = "$Id: glareval.c,v 2.8 2003/06/27 06:53:23 greg Exp $";
#endif
/*
 * Compute pixels for glare calculation
 */

#include "copyright.h"

#include <string.h>

#include "rtprocess.h" /* Windows: must come first because of conflicts */
#include "glare.h"

                                        /* maximum rtrace buffer size */
#define MAXPIX          (4096/(6*sizeof(float)))

#define MAXSBUF         786432  /* maximum total size of scanline buffer */
#define HSIZE           317     /* size of scanline hash table */
#define NRETIRE         16      /* number of scanlines to retire at once */

static SUBPROC  rt_pd = SP_INACTIVE; /* process id & descriptors for rtrace */

FILE    *pictfp = NULL;         /* picture file pointer */
double  exposure;               /* picture exposure */
int     pxsiz, pysiz;           /* picture dimensions */

static int      curpos;         /* current scanline */
static long     *scanpos;       /* scanline positions */

typedef struct scan {
        int     y;              /* scanline position */
        long    lused;          /* for LRU replacement */
        struct scan     *next;  /* next in this hash or free list */
        /* followed by the scanline data */
} SCAN;                 /* buffered scanline */

#define scandata(sl)    ((COLR *)((sl)+1))
#define shash(y)        ((y)%HSIZE)

static int      maxpix;         /* maximum number of pixels to buffer */

static SCAN     *freelist;              /* scanline free list */
static SCAN     *hashtab[HSIZE];        /* scanline hash table */

static long     scanbufsiz;             /* size of allocated scanline buffer */

static long     ncall = 0L;     /* number of calls to getpictscan */
static long     nread = 0L;     /* number of scanlines read */
static long     nrecl = 0L;     /* number of scanlines reclaimed */

static int      wrongformat = 0;

SCAN    *scanretire();

extern long     ftell();


SCAN *
claimscan(y)                    /* claim scanline from buffers */
int     y;
{
        int     hi = shash(y);
        SCAN    *slast;
        register SCAN   *sl;

        for (sl = hashtab[hi]; sl != NULL; sl = sl->next)
                if (sl->y == y)                         /* active scanline */
                        return(sl);
        for (slast = NULL, sl = freelist; sl != NULL; slast = sl, sl = sl->next)
                if (sl->y == -1 || sl->y == y || sl->next == NULL) {
                        if (slast == NULL)              /* remove from free */
                                freelist = sl->next;
                        else
                                slast->next = sl->next;
                        if (sl->y == y) {               /* reclaim */
                                sl->next = hashtab[hi];
                                hashtab[hi] = sl;
                                nrecl++;
                        }
                        return(sl);
                }
        return(scanretire());           /* need more free scanlines */
}


COLR *
getpictscan(y)                  /* get picture scanline */
int     y;
{
        register SCAN   *sl;
        register int    i;
                                        /* first check our buffers */
        sl = claimscan(y);
        if (sl == NULL)
                memerr("claimscan()");
        sl->lused = ncall++;
        if (sl->y == y)                 /* scan hit */
                return(scandata(sl));
                                        /* else read in replacement */
        if (scanpos[y] < 0) {                   /* need to search */
                for (i = y+1; i < curpos; i++)
                        if (scanpos[i] >= 0) {
                                if (fseek(pictfp, scanpos[i], 0) < 0)
                                        goto seekerr;
                                curpos = i;
                                break;
                        }
                while (curpos >= y) {
                        scanpos[curpos] = ftell(pictfp);
                        if (freadcolrs(scandata(sl), pxsiz, pictfp) < 0)
                                goto readerr;
                        nread++;
                        curpos--;
                }
        } else {
                if (curpos != y && fseek(pictfp, scanpos[y], 0) < 0)
                        goto seekerr;
                if (freadcolrs(scandata(sl), pxsiz, pictfp) < 0)
                        goto readerr;
                nread++;
                curpos = y-1;
        }
        sl->y = y;
        i = shash(y);                   /* add to hash list */
        sl->next = hashtab[i];
        hashtab[i] = sl;
        return(scandata(sl));
readerr:
        fprintf(stderr, "%s: picture read error\n", progname);
        exit(1);
seekerr:
        fprintf(stderr, "%s: picture seek error\n", progname);
        exit(1);
}


#ifdef DEBUG
pict_stats()                    /* print out picture read statistics */
{
        static long     lastcall = 0L;  /* ncall at last report */
        static long     lastread = 0L;  /* nread at last report */
        static long     lastrecl = 0L;  /* nrecl at last report */

        if (ncall == lastcall)
                return;
        fprintf(stderr, "%s: %ld scanlines read (%ld reclaimed) in %ld calls\n",
                progname, nread-lastread, nrecl-lastrecl, ncall-lastcall);
        lastcall = ncall;
        lastread = nread;
        lastrecl = nrecl;
}
#endif


double
pict_val(vd)                    /* find picture value for view direction */
FVECT   vd;
{
        FVECT   pp;
        FVECT   ip;
        COLOR   res;

        if (pictfp == NULL)
                return(-1.0);
        pp[0] = pictview.vp[0] + vd[0];
        pp[1] = pictview.vp[1] + vd[1];
        pp[2] = pictview.vp[2] + vd[2];
        viewloc(ip, &pictview, pp);
        if (ip[2] <= FTINY || ip[0] < 0. || ip[0] >= 1. ||
                        ip[1] < 0. || ip[1] >= 1.)
                return(-1.0);
        colr_color(res, getpictscan((int)(ip[1]*pysiz))[(int)(ip[0]*pxsiz)]);
        return(luminance(res)/exposure);
}


double
getviewpix(vh, vv)              /* compute single view pixel */
int     vh, vv;
{
        FVECT   dir;
        float   rt_buf[12];
        double  res;

        if (compdir(dir, vh, vv) < 0)
                return(-1.0);
        npixinvw++;
        if ((res = pict_val(dir)) >= 0.0)
                return(res);
        if (rt_pd.r == -1) {
                npixmiss++;
                return(-1.0);
        }
        rt_buf[0] = ourview.vp[0];
        rt_buf[1] = ourview.vp[1];
        rt_buf[2] = ourview.vp[2];
        rt_buf[3] = dir[0];
        rt_buf[4] = dir[1];
        rt_buf[5] = dir[2];
        rt_compute(rt_buf, 1);
        return(luminance(rt_buf));
}


getviewspan(vv, vb)             /* compute a span of view pixels */
int     vv;
float   *vb;
{
        float   rt_buf[6*MAXPIX];       /* rtrace send/receive buffer */
        register int    n;              /* number of pixels in buffer */
        short   buf_vh[MAXPIX];         /* pixel positions */
        FVECT   dir;
        register int    vh;

#ifdef DEBUG
        if (verbose)
                fprintf(stderr, "%s: computing view span at %d...\n",
                                progname, vv);
#endif
        n = 0;
        for (vh = -hsize; vh <= hsize; vh++) {
                if (compdir(dir, vh, vv) < 0) {         /* not in view */
                        vb[vh+hsize] = -1.0;
                        continue;
                }
                npixinvw++;
                if ((vb[vh+hsize] = pict_val(dir)) >= 0.0)
                        continue;
                if (rt_pd.r == -1) {            /* missing information */
                        npixmiss++;
                        continue;
                }
                                                /* send to rtrace */
                if (n >= maxpix) {                      /* flush */
                        rt_compute(rt_buf, n);
                        while (n-- > 0)
                                vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n);
                }
                rt_buf[6*n] = ourview.vp[0];
                rt_buf[6*n+1] = ourview.vp[1];
                rt_buf[6*n+2] = ourview.vp[2];
                rt_buf[6*n+3] = dir[0];
                rt_buf[6*n+4] = dir[1];
                rt_buf[6*n+5] = dir[2];
                buf_vh[n++] = vh;
        }
#ifdef DEBUG
        if (verbose)
                pict_stats();
#endif
        if (n > 0) {                            /* process pending buffer */
                rt_compute(rt_buf, n);
                while (n-- > 0)
                        vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n);
        }
}


rt_compute(pb, np)              /* process buffer through rtrace */
float   *pb;
int     np;
{
#ifdef DEBUG
        if (verbose && np > 1)
                fprintf(stderr, "%s: sending %d samples to rtrace...\n",
                                progname, np);
#endif
        memset(pb+6*np, '\0', 6*sizeof(float));
        if (process(&rt_pd, (char *)pb, (char *)pb, 3*sizeof(float)*(np+1),
                        6*sizeof(float)*(np+1)) < 3*sizeof(float)*(np+1)) {
                fprintf(stderr, "%s: rtrace communication error\n",
                                progname);
                exit(1);
        }
}


int
getexpos(s)                     /* get exposure from header line */
char    *s;
{
        char    fmt[32];

        if (isexpos(s))
                exposure *= exposval(s);
        else if (isformat(s)) {
                formatval(fmt, s);
                wrongformat = strcmp(fmt, COLRFMT);
        }
        return(0);
}


open_pict(fn)                   /* open picture file */
char    *fn;
{
        if ((pictfp = fopen(fn, "r")) == NULL) {
                fprintf(stderr, "%s: cannot open\n", fn);
                exit(1);
        }
        exposure = 1.0;
        getheader(pictfp, getexpos, NULL);
        if (wrongformat || !fscnresolu(&pxsiz, &pysiz, pictfp)) {
                fprintf(stderr, "%s: incompatible picture format\n", fn);
                exit(1);
        }
        initscans();
}


close_pict()                    /* done with picture */
{
        if (pictfp == NULL)
                return;
        fclose(pictfp);
        donescans();
        pictfp = NULL;
}


fork_rtrace(av)                 /* open pipe and start rtrace */
char    *av[];
{
        int     rval;

        rval = open_process(&rt_pd, av);
        if (rval < 0) {
                perror(progname);
                exit(1);
        }
        if (rval == 0) {
                fprintf(stderr, "%s: command not found\n", av[0]);
                exit(1);
        }
        maxpix = rval/(6*sizeof(float));
        if (maxpix > MAXPIX)
                maxpix = MAXPIX;
        maxpix--;
}


done_rtrace()                   /* wait for rtrace to finish */
{
        int     status;

        status = close_process(&rt_pd);
        if (status > 0) {
                fprintf(stderr, "%s: bad status (%d) from rtrace\n",
                                progname, status);
                exit(1);
        }
        rt_pd.r = -1;
}


SCAN *
scanretire()                    /* retire old scanlines to free list */
{
        SCAN    *sold[NRETIRE];
        int     n;
        int     h;
        register SCAN   *sl;
        register int    i;
                                        /* grab the NRETIRE oldest scanlines */
        sold[n = 0] = NULL;
        for (h = 0; h < HSIZE; h++)
                for (sl = hashtab[h]; sl != NULL; sl = sl->next) {
                        for (i = n; i && sold[i-1]->lused > sl->lused; i--)
                                if (i < NRETIRE)
                                        sold[i] = sold[i-1];
                        if (i < NRETIRE) {
                                sold[i] = sl;
                                if (n < NRETIRE)        /* grow list */
                                        n++;
                        }
                }
                                        /* put scanlines into free list */
        for (i = 0; i < n; i++) {
                h = shash(sold[i]->y);
                sl = hashtab[h];
                if (sl == sold[i])
                        hashtab[h] = sl->next;
                else {
                        while (sl->next != sold[i])     /* IS in list */
                                sl = sl->next;
                        sl->next = sold[i]->next;
                }
                if (i > 0) {            /* save oldest as return value */
                        sold[i]->next = freelist;
                        freelist = sold[i];
                }
        }
        return(sold[0]);
}


static char     *scan_buf;


initscans()                             /* initialize scanline buffers */
{
        int     scansize;
        register SCAN   *ptr;
        register int    i;
                                        /* initialize positions */
        scanpos = (long *)bmalloc(pysiz*sizeof(long));
        if (scanpos == NULL)
                memerr("scanline positions");
        for (i = pysiz-1; i >= 0; i--)
                scanpos[i] = -1L;
        curpos = pysiz-1;
                                        /* clear hash table */
        for (i = 0; i < HSIZE; i++)
                hashtab[i] = NULL;
                                        /* allocate scanline buffers */
        scansize = sizeof(SCAN) + pxsiz*sizeof(COLR);
#ifdef ALIGNT
        scansize = scansize+(sizeof(ALIGNT)-1) & ~(sizeof(ALIGNT)-1);
#endif
        i = MAXSBUF / scansize;         /* compute number to allocate */
        if (i > HSIZE)
                i = HSIZE;
        scanbufsiz = i*scansize;
        scan_buf = bmalloc(scanbufsiz); /* get in one big chunk */
        if (scan_buf == NULL)
                memerr("scanline buffers");
        ptr = (SCAN *)scan_buf;
        freelist = NULL;                /* build our free list */
        while (i-- > 0) {
                ptr->y = -1;
                ptr->lused = -1;
                ptr->next = freelist;
                freelist = ptr;
                ptr = (SCAN *)((char *)ptr + scansize); /* beware of C bugs */
        }
}


donescans()                             /* free up scanlines */
{
        bfree(scan_buf, scanbufsiz);
        bfree((char *)scanpos, pysiz*sizeof(long));
}
Revision:	2.9
Committed:	Mon Jun 30 14:59:13 2003 UTC (20 years, 9 months ago) by schorsch
Content type:	text/plain
Branch:	MAIN
Changes since 2.8:	+6 -2 lines
Log Message:	Replaced most outdated BSD function calls with their posix equivalents, and cleaned up a few other platform dependencies.
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	schorsch	2.9	static const char RCSid[] = "$Id: glareval.c,v 2.8 2003/06/27 06:53:23 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* Compute pixels for glare calculation
6			*/
7
8	schorsch	2.9	#include "copyright.h"
9
10			#include <string.h>
11
12	schorsch	2.7	#include "rtprocess.h" /* Windows: must come first because of conflicts */
13	greg	1.1	#include "glare.h"
14	schorsch	2.7
15	greg	1.19	/* maximum rtrace buffer size */
16			#define MAXPIX (4096/(6*sizeof(float)))
17	greg	1.1
18	greg	1.16	#define MAXSBUF 786432 /* maximum total size of scanline buffer */
19	greg	1.9	#define HSIZE 317 /* size of scanline hash table */
20	greg	1.8	#define NRETIRE 16 /* number of scanlines to retire at once */
21	greg	1.1
22	schorsch	2.7	static SUBPROC rt_pd = SP_INACTIVE; /* process id & descriptors for rtrace */
23	greg	1.1
24			FILE pictfp = NULL; / picture file pointer */
25			double exposure; /* picture exposure */
26			int pxsiz, pysiz; /* picture dimensions */
27	greg	1.8
28			static int curpos; /* current scanline */
29			static long scanpos; / scanline positions */
30
31			typedef struct scan {
32			int y; /* scanline position */
33	greg	1.1	long lused; /* for LRU replacement */
34	greg	1.8	struct scan next; / next in this hash or free list */
35			/* followed by the scanline data */
36			} SCAN; /* buffered scanline */
37	greg	1.1
38	greg	1.8	#define scandata(sl) ((COLR *)((sl)+1))
39			#define shash(y) ((y)%HSIZE)
40
41	greg	1.19	static int maxpix; /* maximum number of pixels to buffer */
42
43	greg	1.8	static SCAN freelist; / scanline free list */
44			static SCAN hashtab[HSIZE]; / scanline hash table */
45
46	greg	2.2	static long scanbufsiz; /* size of allocated scanline buffer */
47
48	greg	1.2	static long ncall = 0L; /* number of calls to getpictscan */
49			static long nread = 0L; /* number of scanlines read */
50	greg	1.15	static long nrecl = 0L; /* number of scanlines reclaimed */
51	greg	1.1
52	greg	1.13	static int wrongformat = 0;
53
54	greg	1.8	SCAN *scanretire();
55
56	greg	1.5	extern long ftell();
57	greg	1.2
58	greg	1.5
59	greg	1.8	SCAN *
60			claimscan(y) /* claim scanline from buffers */
61			int y;
62			{
63			int hi = shash(y);
64			SCAN *slast;
65			register SCAN *sl;
66
67			for (sl = hashtab[hi]; sl != NULL; sl = sl->next)
68			if (sl->y == y) /* active scanline */
69			return(sl);
70			for (slast = NULL, sl = freelist; sl != NULL; slast = sl, sl = sl->next)
71			if (sl->y == -1 \|\| sl->y == y \|\| sl->next == NULL) {
72			if (slast == NULL) /* remove from free */
73			freelist = sl->next;
74			else
75			slast->next = sl->next;
76			if (sl->y == y) { /* reclaim */
77			sl->next = hashtab[hi];
78			hashtab[hi] = sl;
79	greg	1.15	nrecl++;
80	greg	1.8	}
81			return(sl);
82			}
83			return(scanretire()); /* need more free scanlines */
84			}
85
86
87	greg	1.1	COLR *
88			getpictscan(y) /* get picture scanline */
89			int y;
90			{
91	greg	1.8	register SCAN *sl;
92	greg	1.1	register int i;
93			/* first check our buffers */
94	greg	1.8	sl = claimscan(y);
95			if (sl == NULL)
96			memerr("claimscan()");
97			sl->lused = ncall++;
98			if (sl->y == y) /* scan hit */
99			return(scandata(sl));
100			/* else read in replacement */
101	greg	1.5	if (scanpos[y] < 0) { /* need to search */
102			for (i = y+1; i < curpos; i++)
103			if (scanpos[i] >= 0) {
104			if (fseek(pictfp, scanpos[i], 0) < 0)
105			goto seekerr;
106			curpos = i;
107			break;
108			}
109			while (curpos >= y) {
110	greg	1.1	scanpos[curpos] = ftell(pictfp);
111	greg	1.8	if (freadcolrs(scandata(sl), pxsiz, pictfp) < 0)
112	greg	1.1	goto readerr;
113	greg	1.5	nread++;
114	greg	1.1	curpos--;
115			}
116	greg	1.5	} else {
117			if (curpos != y && fseek(pictfp, scanpos[y], 0) < 0)
118			goto seekerr;
119	greg	1.8	if (freadcolrs(scandata(sl), pxsiz, pictfp) < 0)
120	greg	1.5	goto readerr;
121			nread++;
122			curpos = y-1;
123	greg	1.1	}
124	greg	1.8	sl->y = y;
125			i = shash(y); /* add to hash list */
126			sl->next = hashtab[i];
127			hashtab[i] = sl;
128			return(scandata(sl));
129	greg	1.1	readerr:
130			fprintf(stderr, "%s: picture read error\n", progname);
131			exit(1);
132	greg	1.5	seekerr:
133			fprintf(stderr, "%s: picture seek error\n", progname);
134			exit(1);
135	greg	1.1	}
136
137
138	greg	1.6	#ifdef DEBUG
139	greg	1.2	pict_stats() /* print out picture read statistics */
140			{
141			static long lastcall = 0L; /* ncall at last report */
142			static long lastread = 0L; /* nread at last report */
143	greg	1.15	static long lastrecl = 0L; /* nrecl at last report */
144	greg	1.2
145			if (ncall == lastcall)
146			return;
147	greg	1.15	fprintf(stderr, "%s: %ld scanlines read (%ld reclaimed) in %ld calls\n",
148			progname, nread-lastread, nrecl-lastrecl, ncall-lastcall);
149	greg	1.2	lastcall = ncall;
150			lastread = nread;
151	greg	1.15	lastrecl = nrecl;
152	greg	1.2	}
153	greg	1.6	#endif
154	greg	1.2
155
156	greg	1.1	double
157			pict_val(vd) /* find picture value for view direction */
158			FVECT vd;
159			{
160			FVECT pp;
161	greg	1.21	FVECT ip;
162	greg	1.1	COLOR res;
163
164			if (pictfp == NULL)
165			return(-1.0);
166			pp[0] = pictview.vp[0] + vd[0];
167			pp[1] = pictview.vp[1] + vd[1];
168			pp[2] = pictview.vp[2] + vd[2];
169	greg	1.21	viewloc(ip, &pictview, pp);
170			if (ip[2] <= FTINY \|\| ip[0] < 0. \|\| ip[0] >= 1. \|\|
171			ip[1] < 0. \|\| ip[1] >= 1.)
172	greg	1.1	return(-1.0);
173	greg	1.21	colr_color(res, getpictscan((int)(ip[1]pysiz))[(int)(ip[0]pxsiz)]);
174	greg	1.1	return(luminance(res)/exposure);
175			}
176
177
178			double
179	greg	1.14	getviewpix(vh, vv) /* compute single view pixel */
180	greg	1.1	int vh, vv;
181			{
182			FVECT dir;
183	greg	1.19	float rt_buf[12];
184	greg	1.1	double res;
185
186	greg	1.14	if (compdir(dir, vh, vv) < 0)
187	greg	1.1	return(-1.0);
188	greg	1.7	npixinvw++;
189	greg	1.1	if ((res = pict_val(dir)) >= 0.0)
190			return(res);
191	schorsch	2.7	if (rt_pd.r == -1) {
192	greg	1.7	npixmiss++;
193	greg	1.1	return(-1.0);
194	greg	1.7	}
195	greg	1.1	rt_buf[0] = ourview.vp[0];
196			rt_buf[1] = ourview.vp[1];
197			rt_buf[2] = ourview.vp[2];
198			rt_buf[3] = dir[0];
199			rt_buf[4] = dir[1];
200			rt_buf[5] = dir[2];
201			rt_compute(rt_buf, 1);
202			return(luminance(rt_buf));
203			}
204
205
206			getviewspan(vv, vb) /* compute a span of view pixels */
207			int vv;
208			float *vb;
209			{
210			float rt_buf[6MAXPIX]; / rtrace send/receive buffer */
211	greg	1.3	register int n; /* number of pixels in buffer */
212	greg	1.1	short buf_vh[MAXPIX]; /* pixel positions */
213			FVECT dir;
214			register int vh;
215
216	greg	1.4	#ifdef DEBUG
217	greg	1.1	if (verbose)
218			fprintf(stderr, "%s: computing view span at %d...\n",
219			progname, vv);
220	greg	1.4	#endif
221	greg	1.3	n = 0;
222	greg	1.1	for (vh = -hsize; vh <= hsize; vh++) {
223	greg	1.14	if (compdir(dir, vh, vv) < 0) { /* not in view */
224	greg	1.1	vb[vh+hsize] = -1.0;
225			continue;
226			}
227	greg	1.7	npixinvw++;
228	greg	1.1	if ((vb[vh+hsize] = pict_val(dir)) >= 0.0)
229			continue;
230	schorsch	2.7	if (rt_pd.r == -1) { /* missing information */
231	greg	1.7	npixmiss++;
232	greg	1.1	continue;
233	greg	1.7	}
234	greg	1.1	/* send to rtrace */
235	greg	1.19	if (n >= maxpix) { /* flush */
236	greg	1.3	rt_compute(rt_buf, n);
237			while (n-- > 0)
238			vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n);
239	greg	1.1	}
240	greg	1.3	rt_buf[6*n] = ourview.vp[0];
241			rt_buf[6*n+1] = ourview.vp[1];
242			rt_buf[6*n+2] = ourview.vp[2];
243			rt_buf[6*n+3] = dir[0];
244			rt_buf[6*n+4] = dir[1];
245			rt_buf[6*n+5] = dir[2];
246			buf_vh[n++] = vh;
247	greg	1.1	}
248	greg	1.4	#ifdef DEBUG
249	greg	1.2	if (verbose)
250			pict_stats();
251	greg	1.4	#endif
252	greg	1.3	if (n > 0) { /* process pending buffer */
253			rt_compute(rt_buf, n);
254			while (n-- > 0)
255			vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n);
256			}
257	greg	1.1	}
258
259
260			rt_compute(pb, np) /* process buffer through rtrace */
261			float *pb;
262			int np;
263			{
264	greg	1.4	#ifdef DEBUG
265	greg	1.1	if (verbose && np > 1)
266			fprintf(stderr, "%s: sending %d samples to rtrace...\n",
267			progname, np);
268	greg	1.4	#endif
269	schorsch	2.9	memset(pb+6np, '\0', 6sizeof(float));
270	schorsch	2.7	if (process(&rt_pd, (char )pb, (char )pb, 3sizeof(float)(np+1),
271	gregl	2.4	6sizeof(float)(np+1)) < 3sizeof(float)(np+1)) {
272	greg	1.19	fprintf(stderr, "%s: rtrace communication error\n",
273	greg	1.1	progname);
274			exit(1);
275			}
276			}
277
278
279	gwlarson	2.5	int
280	greg	1.1	getexpos(s) /* get exposure from header line */
281			char *s;
282			{
283	greg	1.13	char fmt[32];
284
285	greg	1.1	if (isexpos(s))
286			exposure *= exposval(s);
287	greg	1.13	else if (isformat(s)) {
288			formatval(fmt, s);
289			wrongformat = strcmp(fmt, COLRFMT);
290			}
291	gwlarson	2.5	return(0);
292	greg	1.1	}
293
294
295			open_pict(fn) /* open picture file */
296			char *fn;
297			{
298			if ((pictfp = fopen(fn, "r")) == NULL) {
299	greg	2.3	fprintf(stderr, "%s: cannot open\n", fn);
300	greg	1.1	exit(1);
301			}
302			exposure = 1.0;
303	greg	1.13	getheader(pictfp, getexpos, NULL);
304	greg	1.21	if (wrongformat \|\| !fscnresolu(&pxsiz, &pysiz, pictfp)) {
305			fprintf(stderr, "%s: incompatible picture format\n", fn);
306	greg	1.1	exit(1);
307			}
308	greg	1.8	initscans();
309	greg	1.1	}
310
311
312			close_pict() /* done with picture */
313			{
314			if (pictfp == NULL)
315			return;
316			fclose(pictfp);
317	greg	1.8	donescans();
318	greg	1.1	pictfp = NULL;
319			}
320
321
322			fork_rtrace(av) /* open pipe and start rtrace */
323			char *av[];
324			{
325	greg	1.19	int rval;
326	greg	1.1
327	schorsch	2.7	rval = open_process(&rt_pd, av);
328	greg	1.19	if (rval < 0) {
329	greg	1.1	perror(progname);
330			exit(1);
331			}
332	greg	1.19	if (rval == 0) {
333			fprintf(stderr, "%s: command not found\n", av[0]);
334	greg	1.1	exit(1);
335			}
336	greg	1.19	maxpix = rval/(6*sizeof(float));
337			if (maxpix > MAXPIX)
338			maxpix = MAXPIX;
339			maxpix--;
340	greg	1.1	}
341
342
343			done_rtrace() /* wait for rtrace to finish */
344			{
345	greg	1.19	int status;
346	greg	1.1
347	schorsch	2.7	status = close_process(&rt_pd);
348	greg	1.19	if (status > 0) {
349	greg	1.1	fprintf(stderr, "%s: bad status (%d) from rtrace\n",
350			progname, status);
351			exit(1);
352			}
353	schorsch	2.7	rt_pd.r = -1;
354	greg	1.8	}
355
356
357			SCAN *
358			scanretire() /* retire old scanlines to free list */
359			{
360			SCAN *sold[NRETIRE];
361			int n;
362			int h;
363			register SCAN *sl;
364			register int i;
365			/* grab the NRETIRE oldest scanlines */
366			sold[n = 0] = NULL;
367	greg	1.10	for (h = 0; h < HSIZE; h++)
368			for (sl = hashtab[h]; sl != NULL; sl = sl->next) {
369			for (i = n; i && sold[i-1]->lused > sl->lused; i--)
370			if (i < NRETIRE)
371	greg	1.8	sold[i] = sold[i-1];
372			if (i < NRETIRE) {
373	greg	1.10	sold[i] = sl;
374	greg	1.8	if (n < NRETIRE) /* grow list */
375			n++;
376	greg	1.10	}
377			}
378			/* put scanlines into free list */
379			for (i = 0; i < n; i++) {
380			h = shash(sold[i]->y);
381			sl = hashtab[h];
382			if (sl == sold[i])
383			hashtab[h] = sl->next;
384			else {
385			while (sl->next != sold[i]) /* IS in list */
386	greg	1.8	sl = sl->next;
387	greg	1.10	sl->next = sold[i]->next;
388	greg	1.8	}
389	greg	1.10	if (i > 0) { /* save oldest as return value */
390			sold[i]->next = freelist;
391			freelist = sold[i];
392			}
393	greg	1.8	}
394			return(sold[0]);
395			}
396
397
398			static char *scan_buf;
399
400
401			initscans() /* initialize scanline buffers */
402			{
403			int scansize;
404			register SCAN *ptr;
405			register int i;
406			/* initialize positions */
407	greg	2.2	scanpos = (long )bmalloc(pysizsizeof(long));
408	greg	1.8	if (scanpos == NULL)
409			memerr("scanline positions");
410			for (i = pysiz-1; i >= 0; i--)
411			scanpos[i] = -1L;
412			curpos = pysiz-1;
413			/* clear hash table */
414			for (i = 0; i < HSIZE; i++)
415			hashtab[i] = NULL;
416			/* allocate scanline buffers */
417			scansize = sizeof(SCAN) + pxsiz*sizeof(COLR);
418	greg	2.8	#ifdef ALIGNT
419			scansize = scansize+(sizeof(ALIGNT)-1) & ~(sizeof(ALIGNT)-1);
420	greg	1.8	#endif
421			i = MAXSBUF / scansize; /* compute number to allocate */
422			if (i > HSIZE)
423			i = HSIZE;
424	greg	2.2	scanbufsiz = i*scansize;
425			scan_buf = bmalloc(scanbufsiz); /* get in one big chunk */
426	greg	1.8	if (scan_buf == NULL)
427			memerr("scanline buffers");
428			ptr = (SCAN *)scan_buf;
429			freelist = NULL; /* build our free list */
430			while (i-- > 0) {
431			ptr->y = -1;
432			ptr->lused = -1;
433			ptr->next = freelist;
434			freelist = ptr;
435			ptr = (SCAN )((char )ptr + scansize); /* beware of C bugs */
436			}
437			}
438
439
440			donescans() /* free up scanlines */
441			{
442	greg	2.2	bfree(scan_buf, scanbufsiz);
443			bfree((char )scanpos, pysizsizeof(long));
444	greg	1.1	}