src/util/glareval.c

/* Copyright (c) 1991 Regents of the University of California */

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

/*
 * Compute pixels for glare calculation
 */

#include "glare.h"
#include <sys/param.h>
                                        /* compute rtrace buffer size */
#ifndef PIPE_BUF
#define PIPE_BUF        512             /* hyperconservative */
#endif
#define MAXPIX          (PIPE_BUF/(6*sizeof(float)) - 1)

#ifndef BSD
#define vfork           fork
#endif

#define NSCANS          64              /* number of scanlines to buffer */

int     rt_pid = -1;            /* process id for rtrace */
int     fd_tort, fd_fromrt;     /* pipe descriptors */

FILE    *pictfp = NULL;         /* picture file pointer */
double  exposure;               /* picture exposure */
int     pxsiz, pysiz;           /* picture dimensions */
int     curpos;                 /* current scanline */
long    *scanpos;               /* scanline positions */
struct {
        long    lused;          /* for LRU replacement */
        int     y;              /* scanline position */
        COLR    *sl;            /* scanline contents */
} scan[NSCANS];         /* buffered scanlines */

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


COLR *
getpictscan(y)                  /* get picture scanline */
int     y;
{
        extern long     ftell();
        int     minused;
        register int    i;
                                        /* first check our buffers */
        ncall++;
        minused = 0;
        for (i = 0; i < NSCANS; i++) {
                if (scan[i].y == y) {
                        scan[i].lused = ncall;
                        return(scan[i].sl);
                }
                if (scan[i].lused < scan[minused].lused)
                        minused = i;
        }
                                        /* not there, read it in */
        if (scanpos[y] == -1) {                 /* need to search */
                while (curpos > y) {
                        scanpos[curpos] = ftell(pictfp);
                        if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0)
                                goto readerr;
                        curpos--;
                }
        } else if (fseek(pictfp, scanpos[y], 0) < 0) {
                fprintf(stderr, "%s: picture seek error\n", progname);
                exit(1);
        }
        if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0)
                goto readerr;
        nread++;
        curpos = y-1;
        scan[minused].lused = ncall;
        scan[minused].y = y;
        return(scan[minused].sl);
readerr:
        fprintf(stderr, "%s: picture read error\n", progname);
        exit(1);
}


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

        if (ncall == lastcall)
                return;
        fprintf(stderr, "%s: %ld scanlines read, %ld reused\n",
                        progname, nread-lastread,
                        (ncall-lastcall)-(nread-lastread));
        lastcall = ncall;
        lastread = nread;
}


double
pict_val(vd)                    /* find picture value for view direction */
FVECT   vd;
{
        FVECT   pp;
        double  vpx, vpy, vpz;
        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];
        viewpixel(&vpx, &vpy, &vpz, &pictview, pp);
        if (vpz <= FTINY || vpx < 0. || vpx >= 1. || vpy < 0. || vpy >= 1.)
                return(-1.0);
        colr_color(res, getpictscan((int)(vpy*pysiz))[(int)(vpx*pxsiz)]);
        return(luminance(res)/exposure);
}


double
getviewpix(vh, vv)              /* compute single view pixel */
int     vh, vv;
{
        FVECT   dir;
        float   rt_buf[6];
        double  res;

        if (compdir(dir, vh, vv) < 0)
                return(-1.0);
        if ((res = pict_val(dir)) >= 0.0)
                return(res);
        if (rt_pid == -1)
                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;

        if (verbose)
                fprintf(stderr, "%s: computing view span at %d...\n",
                                progname, vv);
        n = 0;
        for (vh = -hsize; vh <= hsize; vh++) {
                if (compdir(dir, vh, vv) < 0) { /* off viewable region */
                        vb[vh+hsize] = -1.0;
                        continue;
                }
                if ((vb[vh+hsize] = pict_val(dir)) >= 0.0)
                        continue;
                if (rt_pid == -1)               /* missing information */
                        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;
        }
        if (verbose)
                pict_stats();
        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;
{
        static float    nbuf[6] = {0.,0.,0.,0.,0.,0.};

        if (verbose && np > 1)
                fprintf(stderr, "%s: sending %d samples to rtrace...\n",
                                progname, np);
        if (writebuf(fd_tort,(char *)pb,6*sizeof(float)*np) < 6*sizeof(float)*np
                || writebuf(fd_tort,(char *)nbuf,sizeof(nbuf)) < sizeof(nbuf)) {
                fprintf(stderr, "%s: error writing to rtrace process\n",
                                progname);
                exit(1);
        }
        if (readbuf(fd_fromrt, (char *)pb, 3*sizeof(float)*np)
                        < 3*sizeof(float)*np) {
                fprintf(stderr, "%s: error reading from rtrace process\n",
                                progname);
                exit(1);
        }
}


getexpos(s)                     /* get exposure from header line */
char    *s;
{
        if (isexpos(s))
                exposure *= exposval(s);
}


open_pict(fn)                   /* open picture file */
char    *fn;
{
        register int    i;

        if ((pictfp = fopen(fn, "r")) == NULL) {
                fprintf("%s: cannot open\n", fn);
                exit(1);
        }
        exposure = 1.0;
        getheader(pictfp, getexpos);
        if (fgetresolu(&pxsiz, &pysiz, pictfp) != (YMAJOR|YDECR)) {
                fprintf("%s: bad picture resolution\n", fn);
                exit(1);
        }
        scanpos = (long *)malloc(pysiz*sizeof(long));
        if (scanpos == NULL)
                memerr("scanline positions");
        for (i = 0; i < pysiz; i++)
                scanpos[i] = -1L;
        for (i = 0; i < NSCANS; i++) {
                scan[i].lused = -1;
                scan[i].y = -1;
                scan[i].sl = (COLR *)malloc(pxsiz*sizeof(COLR));
                if (scan[i].sl == NULL)
                        memerr("scanline buffers");
        }
        curpos = pysiz-1;
}


close_pict()                    /* done with picture */
{
        register int    i;

        if (pictfp == NULL)
                return;
        fclose(pictfp);
        free((char *)scanpos);
        for (i = 0; i < NSCANS; i++)
                free((char *)scan[i].sl);
        pictfp = NULL;
}


fork_rtrace(av)                 /* open pipe and start rtrace */
char    *av[];
{
        int     p0[2], p1[2];

        if (pipe(p0) < 0 || pipe(p1) < 0) {
                perror(progname);
                exit(1);
        }
        if ((rt_pid = vfork()) == 0) {          /* if child */
                close(p0[1]);
                close(p1[0]);
                if (p0[0] != 0) {       /* connect p0 to stdin */
                        dup2(p0[0], 0);
                        close(p0[0]);
                }
                if (p1[1] != 0) {       /* connect p1 to stdout */
                        dup2(p1[1], 1);
                        close(p1[1]);
                }
                execvp(av[0], av);
                perror(av[0]);
                _exit(127);
        }
        if (rt_pid == -1) {
                perror(progname);
                exit(1);
        }
        close(p0[0]);
        close(p1[1]);
        fd_tort = p0[1];
        fd_fromrt = p1[0];
}


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

        if (rt_pid == -1)
                return;
        close(fd_tort);
        close(fd_fromrt);
        while ((pid = wait(&status)) != -1 && pid != rt_pid)
                ;
        if (pid == rt_pid && status != 0) {
                fprintf(stderr, "%s: bad status (%d) from rtrace\n",
                                progname, status);
                exit(1);
        }
        rt_pid = -1;
}


int
readbuf(fd, bpos, siz)
int     fd;
char    *bpos;
int     siz;
{
        register int    cc, nrem = siz;

        while (nrem > 0 && (cc = read(fd, bpos, nrem)) > 0) {
                bpos += cc;
                nrem -= cc;
        }
        if (cc < 0)
                return(cc);
        return(siz-nrem);
}


int
writebuf(fd, bpos, siz)
char    *bpos;
int     siz;
{
        register int    cc, nrem = siz;

        while (nrem > 0 && (cc = write(fd, bpos, nrem)) > 0) {
                bpos += cc;
                nrem -= cc;
        }
        if (cc < 0)
                return(cc);
        return(siz-nrem);
}
Revision:	1.3
Committed:	Tue Mar 19 17:06:27 1991 UTC (33 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+21 -21 lines
Log Message:	various bug fixes and enhancements
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1991 Regents of the University of California */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8			* Compute pixels for glare calculation
9			*/
10
11			#include "glare.h"
12			#include <sys/param.h>
13			/* compute rtrace buffer size */
14			#ifndef PIPE_BUF
15			#define PIPE_BUF 512 /* hyperconservative */
16			#endif
17			#define MAXPIX (PIPE_BUF/(6*sizeof(float)) - 1)
18
19			#ifndef BSD
20			#define vfork fork
21			#endif
22
23	greg	1.3	#define NSCANS 64 /* number of scanlines to buffer */
24	greg	1.1
25			int rt_pid = -1; /* process id for rtrace */
26			int fd_tort, fd_fromrt; /* pipe descriptors */
27
28			FILE pictfp = NULL; / picture file pointer */
29			double exposure; /* picture exposure */
30			int pxsiz, pysiz; /* picture dimensions */
31			int curpos; /* current scanline */
32			long scanpos; / scanline positions */
33			struct {
34			long lused; /* for LRU replacement */
35			int y; /* scanline position */
36			COLR sl; / scanline contents */
37			} scan[NSCANS]; /* buffered scanlines */
38
39	greg	1.2	static long ncall = 0L; /* number of calls to getpictscan */
40			static long nread = 0L; /* number of scanlines read */
41	greg	1.1
42	greg	1.2
43	greg	1.1	COLR *
44			getpictscan(y) /* get picture scanline */
45			int y;
46			{
47			extern long ftell();
48			int minused;
49			register int i;
50			/* first check our buffers */
51			ncall++;
52			minused = 0;
53			for (i = 0; i < NSCANS; i++) {
54			if (scan[i].y == y) {
55			scan[i].lused = ncall;
56			return(scan[i].sl);
57			}
58			if (scan[i].lused < scan[minused].lused)
59			minused = i;
60			}
61			/* not there, read it in */
62			if (scanpos[y] == -1) { /* need to search */
63			while (curpos > y) {
64			scanpos[curpos] = ftell(pictfp);
65			if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0)
66			goto readerr;
67			curpos--;
68			}
69			} else if (fseek(pictfp, scanpos[y], 0) < 0) {
70			fprintf(stderr, "%s: picture seek error\n", progname);
71			exit(1);
72			}
73			if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0)
74			goto readerr;
75	greg	1.2	nread++;
76	greg	1.1	curpos = y-1;
77			scan[minused].lused = ncall;
78			scan[minused].y = y;
79			return(scan[minused].sl);
80			readerr:
81			fprintf(stderr, "%s: picture read error\n", progname);
82			exit(1);
83			}
84
85
86	greg	1.2	pict_stats() /* print out picture read statistics */
87			{
88			static long lastcall = 0L; /* ncall at last report */
89			static long lastread = 0L; /* nread at last report */
90
91			if (ncall == lastcall)
92			return;
93			fprintf(stderr, "%s: %ld scanlines read, %ld reused\n",
94			progname, nread-lastread,
95			(ncall-lastcall)-(nread-lastread));
96			lastcall = ncall;
97			lastread = nread;
98			}
99
100
101	greg	1.1	double
102			pict_val(vd) /* find picture value for view direction */
103			FVECT vd;
104			{
105			FVECT pp;
106			double vpx, vpy, vpz;
107			COLOR res;
108
109			if (pictfp == NULL)
110			return(-1.0);
111			pp[0] = pictview.vp[0] + vd[0];
112			pp[1] = pictview.vp[1] + vd[1];
113			pp[2] = pictview.vp[2] + vd[2];
114			viewpixel(&vpx, &vpy, &vpz, &pictview, pp);
115			if (vpz <= FTINY \|\| vpx < 0. \|\| vpx >= 1. \|\| vpy < 0. \|\| vpy >= 1.)
116			return(-1.0);
117			colr_color(res, getpictscan((int)(vpypysiz))[(int)(vpxpxsiz)]);
118			return(luminance(res)/exposure);
119			}
120
121
122			double
123			getviewpix(vh, vv) /* compute single view pixel */
124			int vh, vv;
125			{
126			FVECT dir;
127			float rt_buf[6];
128			double res;
129
130			if (compdir(dir, vh, vv) < 0)
131			return(-1.0);
132			if ((res = pict_val(dir)) >= 0.0)
133			return(res);
134			if (rt_pid == -1)
135			return(-1.0);
136			rt_buf[0] = ourview.vp[0];
137			rt_buf[1] = ourview.vp[1];
138			rt_buf[2] = ourview.vp[2];
139			rt_buf[3] = dir[0];
140			rt_buf[4] = dir[1];
141			rt_buf[5] = dir[2];
142			rt_compute(rt_buf, 1);
143			return(luminance(rt_buf));
144			}
145
146
147			getviewspan(vv, vb) /* compute a span of view pixels */
148			int vv;
149			float *vb;
150			{
151			float rt_buf[6MAXPIX]; / rtrace send/receive buffer */
152	greg	1.3	register int n; /* number of pixels in buffer */
153	greg	1.1	short buf_vh[MAXPIX]; /* pixel positions */
154			FVECT dir;
155			register int vh;
156
157			if (verbose)
158			fprintf(stderr, "%s: computing view span at %d...\n",
159			progname, vv);
160	greg	1.3	n = 0;
161	greg	1.1	for (vh = -hsize; vh <= hsize; vh++) {
162			if (compdir(dir, vh, vv) < 0) { /* off viewable region */
163			vb[vh+hsize] = -1.0;
164			continue;
165			}
166			if ((vb[vh+hsize] = pict_val(dir)) >= 0.0)
167			continue;
168			if (rt_pid == -1) /* missing information */
169			continue;
170			/* send to rtrace */
171	greg	1.3	if (n >= MAXPIX) { /* flush */
172			rt_compute(rt_buf, n);
173			while (n-- > 0)
174			vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n);
175	greg	1.1	}
176	greg	1.3	rt_buf[6*n] = ourview.vp[0];
177			rt_buf[6*n+1] = ourview.vp[1];
178			rt_buf[6*n+2] = ourview.vp[2];
179			rt_buf[6*n+3] = dir[0];
180			rt_buf[6*n+4] = dir[1];
181			rt_buf[6*n+5] = dir[2];
182			buf_vh[n++] = vh;
183	greg	1.1	}
184	greg	1.2	if (verbose)
185			pict_stats();
186	greg	1.3	if (n > 0) { /* process pending buffer */
187			rt_compute(rt_buf, n);
188			while (n-- > 0)
189			vb[buf_vh[n]+hsize] = luminance(rt_buf+3*n);
190			}
191	greg	1.1	}
192
193
194			rt_compute(pb, np) /* process buffer through rtrace */
195			float *pb;
196			int np;
197			{
198			static float nbuf[6] = {0.,0.,0.,0.,0.,0.};
199
200			if (verbose && np > 1)
201			fprintf(stderr, "%s: sending %d samples to rtrace...\n",
202			progname, np);
203			if (writebuf(fd_tort,(char )pb,6sizeof(float)np) < 6sizeof(float)*np
204			\|\| writebuf(fd_tort,(char *)nbuf,sizeof(nbuf)) < sizeof(nbuf)) {
205			fprintf(stderr, "%s: error writing to rtrace process\n",
206			progname);
207			exit(1);
208			}
209			if (readbuf(fd_fromrt, (char )pb, 3sizeof(float)*np)
210			< 3sizeof(float)np) {
211			fprintf(stderr, "%s: error reading from rtrace process\n",
212			progname);
213			exit(1);
214			}
215			}
216
217
218			getexpos(s) /* get exposure from header line */
219			char *s;
220			{
221			if (isexpos(s))
222			exposure *= exposval(s);
223			}
224
225
226			open_pict(fn) /* open picture file */
227			char *fn;
228			{
229			register int i;
230
231			if ((pictfp = fopen(fn, "r")) == NULL) {
232			fprintf("%s: cannot open\n", fn);
233			exit(1);
234			}
235			exposure = 1.0;
236			getheader(pictfp, getexpos);
237			if (fgetresolu(&pxsiz, &pysiz, pictfp) != (YMAJOR\|YDECR)) {
238			fprintf("%s: bad picture resolution\n", fn);
239			exit(1);
240			}
241			scanpos = (long )malloc(pysizsizeof(long));
242			if (scanpos == NULL)
243			memerr("scanline positions");
244			for (i = 0; i < pysiz; i++)
245			scanpos[i] = -1L;
246			for (i = 0; i < NSCANS; i++) {
247			scan[i].lused = -1;
248			scan[i].y = -1;
249			scan[i].sl = (COLR )malloc(pxsizsizeof(COLR));
250			if (scan[i].sl == NULL)
251			memerr("scanline buffers");
252			}
253			curpos = pysiz-1;
254			}
255
256
257			close_pict() /* done with picture */
258			{
259			register int i;
260
261			if (pictfp == NULL)
262			return;
263			fclose(pictfp);
264			free((char *)scanpos);
265			for (i = 0; i < NSCANS; i++)
266			free((char *)scan[i].sl);
267			pictfp = NULL;
268			}
269
270
271			fork_rtrace(av) /* open pipe and start rtrace */
272			char *av[];
273			{
274			int p0[2], p1[2];
275
276			if (pipe(p0) < 0 \|\| pipe(p1) < 0) {
277			perror(progname);
278			exit(1);
279			}
280			if ((rt_pid = vfork()) == 0) { /* if child */
281			close(p0[1]);
282			close(p1[0]);
283			if (p0[0] != 0) { /* connect p0 to stdin */
284			dup2(p0[0], 0);
285			close(p0[0]);
286			}
287			if (p1[1] != 0) { /* connect p1 to stdout */
288			dup2(p1[1], 1);
289			close(p1[1]);
290			}
291			execvp(av[0], av);
292			perror(av[0]);
293			_exit(127);
294			}
295			if (rt_pid == -1) {
296			perror(progname);
297			exit(1);
298			}
299	greg	1.3	close(p0[0]);
300			close(p1[1]);
301	greg	1.1	fd_tort = p0[1];
302			fd_fromrt = p1[0];
303			}
304
305
306			done_rtrace() /* wait for rtrace to finish */
307			{
308			int pid, status;
309
310			if (rt_pid == -1)
311			return;
312			close(fd_tort);
313			close(fd_fromrt);
314			while ((pid = wait(&status)) != -1 && pid != rt_pid)
315			;
316			if (pid == rt_pid && status != 0) {
317			fprintf(stderr, "%s: bad status (%d) from rtrace\n",
318			progname, status);
319			exit(1);
320			}
321			rt_pid = -1;
322			}
323
324
325			int
326			readbuf(fd, bpos, siz)
327			int fd;
328			char *bpos;
329			int siz;
330			{
331			register int cc, nrem = siz;
332
333			while (nrem > 0 && (cc = read(fd, bpos, nrem)) > 0) {
334			bpos += cc;
335			nrem -= cc;
336			}
337			if (cc < 0)
338			return(cc);
339			return(siz-nrem);
340			}
341
342
343			int
344			writebuf(fd, bpos, siz)
345			char *bpos;
346			int siz;
347			{
348			register int cc, nrem = siz;
349
350			while (nrem > 0 && (cc = write(fd, bpos, nrem)) > 0) {
351			bpos += cc;
352			nrem -= cc;
353			}
354			if (cc < 0)
355			return(cc);
356			return(siz-nrem);
357			}