--- ray/src/rt/rpict.c 1995/12/08 18:49:20 2.41 +++ ray/src/rt/rpict.c 2014/05/09 23:28:57 2.88 @@ -1,52 +1,58 @@ -/* Copyright (c) 1995 Regents of the University of California */ - #ifndef lint -static char SCCSid[] = "$SunId$ LBL"; +static const char RCSid[] = "$Id: rpict.c,v 2.88 2014/05/09 23:28:57 greg Exp $"; #endif - /* * rpict.c - routines and variables for picture generation. - * - * 8/14/85 */ -#include "ray.h" +#include "copyright.h" #include -#ifndef NIX -#ifdef BSD -#include -#include +#include "platform.h" +#ifdef NON_POSIX + #ifdef MINGW + #include + #endif #else -#include -#include -#include + #ifdef BSD + #include + #include + #else + #include + #include + #endif #endif -#endif -extern time_t time(); - +#include #include +#include "ray.h" +#include "paths.h" +#include "ambient.h" #include "view.h" - -#include "resolu.h" - #include "random.h" - #include "paths.h" +#include "hilbert.h" + #define RFTEMPLATE "rfXXXXXX" #ifndef SIGCONT +#ifdef SIGIO /* XXX can we live without this? */ #define SIGCONT SIGIO #endif +#endif +CUBE thescene; /* our scene */ +OBJECT nsceneobjs; /* number of objects in our scene */ + int dimlist[MAXDIM]; /* sampling dimensions */ int ndims = 0; /* number of sampling dimensions */ int samplendx; /* sample index number */ +void (*addobjnotify[])() = {ambnotify, NULL}; + VIEW ourview = STDVIEW; /* view parameters */ int hresolu = 512; /* horizontal resolution */ int vresolu = 512; /* vertical resolution */ @@ -56,6 +62,16 @@ int psample = 4; /* pixel sample size */ double maxdiff = .05; /* max. difference for interpolation */ double dstrpix = 0.67; /* square pixel distribution */ +double mblur = 0.; /* motion blur parameter */ + +double dblur = 0.; /* depth-of-field blur parameter */ + +void (*trace)() = NULL; /* trace call */ + +int do_irrad = 0; /* compute irradiance? */ + +int rand_samp = 0; /* pure Monte Carlo sampling? */ + double dstrsrc = 0.0; /* square source distribution */ double shadthresh = .05; /* shadow threshold */ double shadcert = .5; /* shadow certainty */ @@ -65,7 +81,7 @@ int directvis = 1; /* sources visible? */ double srcsizerat = .25; /* maximum ratio source size/dist. */ COLOR cextinction = BLKCOLOR; /* global extinction coefficient */ -double salbedo = 0.; /* global scattering albedo */ +COLOR salbedo = BLKCOLOR; /* global scattering albedo */ double seccg = 0.; /* global scattering eccentricity */ double ssampdist = 0.; /* scatter sampling distance */ @@ -74,45 +90,50 @@ double specjitter = 1.; /* specular sampling jitter * int backvis = 1; /* back face visibility */ -int maxdepth = 6; /* maximum recursion depth */ -double minweight = 5e-3; /* minimum ray weight */ +int maxdepth = 7; /* maximum recursion depth */ +double minweight = 1e-3; /* minimum ray weight */ +char *ambfile = NULL; /* ambient file name */ COLOR ambval = BLKCOLOR; /* ambient value */ +int ambvwt = 0; /* initial weight for ambient value */ double ambacc = 0.2; /* ambient accuracy */ -int ambres = 32; /* ambient resolution */ -int ambdiv = 128; /* ambient divisions */ -int ambssamp = 0; /* ambient super-samples */ +int ambres = 64; /* ambient resolution */ +int ambdiv = 512; /* ambient divisions */ +int ambssamp = 128; /* ambient super-samples */ int ambounce = 0; /* ambient bounces */ -char *amblist[128]; /* ambient include/exclude list */ +char *amblist[AMBLLEN]; /* ambient include/exclude list */ int ambincl = -1; /* include == 1, exclude == 0 */ -#ifdef MSDOS -int ralrm = 60; /* seconds between reports */ -#else int ralrm = 0; /* seconds between reports */ -#endif double pctdone = 0.0; /* percentage done */ - time_t tlastrept = 0L; /* time at last report */ +time_t tstart; /* starting time */ -extern time_t tstart; /* starting time */ - -extern unsigned long nrays; /* number of rays traced */ - #define MAXDIV 16 /* maximum sample size */ #define pixjitter() (.5+dstrpix*(.5-frandom())) -static int hres, vres; /* resolution for this frame */ +int hres, vres; /* resolution for this frame */ -extern char *mktemp(); +static VIEW lastview; /* the previous view input */ -double pixvalue(); +static void report(int); +static int nextview(FILE *fp); +static void render(char *zfile, char *oldfile); +static void fillscanline(COLOR *scanline, float *zline, char *sd, int xres, + int y, int xstep); +static void fillscanbar(COLOR *scanbar[], float *zbar[], int xres, + int y, int ysize); +static int fillsample(COLOR *colline, float *zline, int x, int y, + int xlen, int ylen, int b); +static double pixvalue(COLOR col, int x, int y); +static int salvage(char *oldfile); +static int pixnumber(int x, int y, int xres, int yres); -#ifdef NIX -#define file_exists(f) (access(f,F_OK)==0) -#else + + +#ifdef RHAS_STAT #include #include int @@ -123,67 +144,66 @@ char *fname; if (stat(fname, &sbuf) < 0) return(0); return((sbuf.st_mode & S_IFREG) != 0); } +#else +#define file_exists(f) (access(f,F_OK)==0) #endif +void quit(code) /* quit program */ int code; { if (code) /* report status */ - report(); + report(0); +#ifndef NON_POSIX headclean(); /* delete header file */ pfclean(); /* clean up persist files */ +#endif exit(code); } -#ifndef NIX -report() /* report progress */ +#ifndef NON_POSIX +static void +report(int dummy) /* report progress */ { - double u, s; + double u, s; #ifdef BSD - char hostname[257]; - struct rusage rubuf; + struct rusage rubuf; #else - struct tms tbuf; - struct utsname nambuf; - double period; -#define hostname nambuf.nodename + double period = 1.0 / 60.0; + struct tms tbuf; #endif tlastrept = time((time_t *)NULL); #ifdef BSD getrusage(RUSAGE_SELF, &rubuf); - u = rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6; - s = rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6; + u = rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec*1e-6; + s = rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec*1e-6; getrusage(RUSAGE_CHILDREN, &rubuf); - u += rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec/1e6; - s += rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec/1e6; - gethostname(hostname, sizeof(hostname)); + u += rubuf.ru_utime.tv_sec + rubuf.ru_utime.tv_usec*1e-6; + s += rubuf.ru_stime.tv_sec + rubuf.ru_stime.tv_usec*1e-6; #else times(&tbuf); #ifdef _SC_CLK_TCK period = 1.0 / sysconf(_SC_CLK_TCK); -#else - period = 1.0 / 60.0; #endif u = ( tbuf.tms_utime + tbuf.tms_cutime ) * period; s = ( tbuf.tms_stime + tbuf.tms_cstime ) * period; - uname(&nambuf); #endif sprintf(errmsg, - "%lu rays, %4.2f%% after %.3fu %.3fs %.3fr hours on %s\n", - nrays, pctdone, u/3600., s/3600., - (tlastrept-tstart)/3600., hostname); + "%lu rays, %4.2f%% after %.3fu %.3fs %.3fr hours on %s (PID %d)\n", + nrays, pctdone, u*(1./3600.), s*(1./3600.), + (tlastrept-tstart)*(1./3600.), myhostname(), getpid()); eputs(errmsg); -#ifndef BSD +#ifdef SIGCONT signal(SIGCONT, report); -#undef hostname #endif } #else -report() /* report progress */ +static void +report(int dummy) /* report progress */ { tlastrept = time((time_t *)NULL); sprintf(errmsg, "%lu rays, %4.2f%% after %5.4f hours\n", @@ -193,9 +213,13 @@ report() /* report progress */ #endif -rpict(seq, pout, zout, prvr) /* generate image(s) */ -int seq; -char *pout, *zout, *prvr; +void +rpict( /* generate image(s) */ + int seq, + char *pout, + char *zout, + char *prvr +) /* * If seq is greater than zero, then we will render a sequence of * images based on view parameter strings read from the standard input. @@ -208,10 +232,9 @@ char *pout, *zout, *prvr; * sequenced file naming. */ { - extern char *rindex(), *strncpy(), *strcat(), *strcpy(); char fbuf[128], fbuf2[128]; int npicts; - register char *cp; + char *cp; RESOLU rs; double pa; /* check sampling */ @@ -227,7 +250,7 @@ char *pout, *zout, *prvr; if (seq <= 0) seq = 0; else if (prvr != NULL && isint(prvr)) { - register int rn; /* skip to specified view */ + int rn; /* skip to specified view */ if ((rn = atoi(prvr)) < seq) error(USER, "recover frame less than start frame"); if (pout == NULL) @@ -235,9 +258,10 @@ char *pout, *zout, *prvr; for ( ; seq < rn; seq++) if (nextview(stdin) == EOF) error(USER, "unexpected EOF on view input"); + setview(&ourview); prvr = fbuf; /* mark for renaming */ } - if (pout != NULL & prvr != NULL) { + if ((pout != NULL) & (prvr != NULL)) { sprintf(fbuf, pout, seq); if (!strcmp(prvr, fbuf)) { /* rename */ strcpy(fbuf2, fbuf); @@ -247,7 +271,7 @@ char *pout, *zout, *prvr; cp--; strcpy(cp, RFTEMPLATE); prvr = mktemp(fbuf2); - if (rename(fbuf, prvr) < 0) + if (rename(fbuf, prvr) < 0) { if (errno == ENOENT) { /* ghost file */ sprintf(errmsg, "new output file \"%s\"", @@ -260,6 +284,7 @@ char *pout, *zout, *prvr; fbuf, prvr); error(SYSTEM, errmsg); } + } } } npicts = 0; /* render sequence */ @@ -276,6 +301,7 @@ char *pout, *zout, *prvr; fbuf); error(USER, errmsg); } + setview(&ourview); continue; /* don't clobber */ } if (freopen(fbuf, "w", stdout) == NULL) { @@ -283,15 +309,12 @@ char *pout, *zout, *prvr; "cannot open output file \"%s\"", fbuf); error(SYSTEM, errmsg); } -#ifdef MSDOS - setmode(fileno(stdout), O_BINARY); -#endif + SET_FILE_BINARY(stdout); dupheader(); } hres = hresolu; vres = vresolu; pa = pixaspect; - if (prvr != NULL) - if (viewfile(prvr, &ourview, &rs) <= 0 - || rs.or != PIXSTANDARD) { + if (prvr != NULL) { + if (viewfile(prvr, &ourview, &rs) <= 0) { sprintf(errmsg, "cannot recover view parameters from \"%s\"", prvr); error(WARNING, errmsg); @@ -300,6 +323,7 @@ char *pout, *zout, *prvr; hres = scanlen(&rs); vres = numscans(&rs); } + } if ((cp = setview(&ourview)) != NULL) error(USER, cp); normaspect(viewaspect(&ourview), &pa, &hres, &vres); @@ -315,8 +339,9 @@ char *pout, *zout, *prvr; fputs(VIEWSTR, stdout); fprintview(&ourview, stdout); putchar('\n'); - if (pa < .99 || pa > 1.01) + if ((pa < .99) | (pa > 1.01)) fputaspect(pa, stdout); + fputnow(stdout); fputformat(COLRFMT, stdout); putchar('\n'); if (zout != NULL) @@ -333,11 +358,14 @@ char *pout, *zout, *prvr; } -nextview(fp) /* get next view from fp */ -FILE *fp; +static int +nextview( /* get next view from fp */ + FILE *fp +) { char linebuf[256]; + lastview = ourview; while (fgets(linebuf, sizeof(linebuf), fp) != NULL) if (isview(linebuf) && sscanview(&ourview, linebuf) > 0) return(0); @@ -345,10 +373,12 @@ FILE *fp; } -render(zfile, oldfile) /* render the scene */ -char *zfile, *oldfile; +static void +render( /* render the scene */ + char *zfile, + char *oldfile +) { - extern long lseek(); COLOR *scanbar[MAXDIV+1]; /* scanline arrays of pixel values */ float *zbar[MAXDIV+1]; /* z values */ char *sampdens; /* previous sample density */ @@ -358,7 +388,13 @@ char *zfile, *oldfile; int zfd; COLOR *colptr; float *zptr; - register int i; + int i; + /* check for empty image */ + if ((hres <= 0) | (vres <= 0)) { + error(WARNING, "empty output picture"); + fprtresolu(0, 0, stdout); + return; + } /* allocate scanlines */ for (i = 0; i <= psample; i++) { scanbar[i] = (COLOR *)malloc(hres*sizeof(COLOR)); @@ -369,7 +405,7 @@ char *zfile, *oldfile; ystep = (psample*99+70)/140; if (hstep > 2) { i = hres/hstep + 2; - if ((sampdens = malloc(i)) == NULL) + if ((sampdens = (char *)malloc(i)) == NULL) goto memerr; while (i--) sampdens[i] = hstep; @@ -381,9 +417,7 @@ char *zfile, *oldfile; sprintf(errmsg, "cannot open z-file \"%s\"", zfile); error(SYSTEM, errmsg); } -#ifdef MSDOS - setmode(zfd, O_BINARY); -#endif + SET_FD_BINARY(zfd); for (i = 0; i <= psample; i++) { zbar[i] = (float *)malloc(hres*sizeof(float)); if (zbar[i] == NULL) @@ -398,17 +432,21 @@ char *zfile, *oldfile; fprtresolu(hres, vres, stdout); /* recover file and compute first */ i = salvage(oldfile); - if (zfd != -1 && i > 0 && - lseek(zfd, (long)i*hres*sizeof(float), 0) == -1) + if (i >= vres) + goto alldone; + if ((zfd != -1) & (i > 0) && + lseek(zfd, (off_t)i*hres*sizeof(float), SEEK_SET) < 0) error(SYSTEM, "z-file seek error in render"); pctdone = 100.0*i/vres; if (ralrm > 0) /* report init stats */ - report(); -#ifndef BSD + report(0); +#ifdef SIGCONT else -#endif signal(SIGCONT, report); - ypos = vres-1 - i; +#endif + ypos = vres-1 - i; /* initialize sampling */ + if (directvis) + init_drawsources(psample); fillscanline(scanbar[0], zbar[0], sampdens, hres, ypos, hstep); /* compute scanlines */ for (ypos -= ystep; ypos > -ystep; ypos -= ystep) { @@ -428,8 +466,10 @@ char *zfile, *oldfile; hres, ypos, hstep); /* fill bar */ fillscanbar(scanbar, zbar, hres, ypos, ystep); + if (directvis) /* add bitty sources */ + drawsources(scanbar, zbar, 0, hres, ypos, ystep); /* write it out */ -#ifndef BSD +#ifdef SIGCONT signal(SIGCONT, SIG_IGN); /* don't interrupt writes */ #endif for (i = ystep; i > 0; i--) { @@ -445,34 +485,39 @@ char *zfile, *oldfile; /* record progress */ pctdone = 100.0*(vres-1-ypos)/vres; if (ralrm > 0 && time((time_t *)NULL) >= tlastrept+ralrm) - report(); -#ifndef BSD + report(0); +#ifdef SIGCONT else signal(SIGCONT, report); #endif } /* clean up */ +#ifdef SIGCONT signal(SIGCONT, SIG_IGN); - if (zfd != -1) { - if (write(zfd, (char *)zbar[0], hres*sizeof(float)) +#endif + if (zfd != -1 && write(zfd, (char *)zbar[0], hres*sizeof(float)) < hres*sizeof(float)) - goto writerr; + goto writerr; + fwritescan(scanbar[0], hres, stdout); + if (fflush(stdout) == EOF) + goto writerr; +alldone: + if (zfd != -1) { if (close(zfd) == -1) goto writerr; for (i = 0; i <= psample; i++) - free((char *)zbar[i]); + free((void *)zbar[i]); } - fwritescan(scanbar[0], hres, stdout); - if (fflush(stdout) == EOF) - goto writerr; for (i = 0; i <= psample; i++) - free((char *)scanbar[i]); + free((void *)scanbar[i]); if (sampdens != NULL) free(sampdens); pctdone = 100.0; if (ralrm > 0) - report(); + report(0); +#ifdef SIGCONT signal(SIGCONT, SIG_DFL); +#endif return; writerr: error(SYSTEM, "write error in render"); @@ -481,17 +526,21 @@ memerr: } -fillscanline(scanline, zline, sd, xres, y, xstep) /* fill scan at y */ -register COLOR *scanline; -register float *zline; -register char *sd; -int xres, y, xstep; +static void +fillscanline( /* fill scan at y */ + COLOR *scanline, + float *zline, + char *sd, + int xres, + int y, + int xstep +) { static int nc = 0; /* number of calls */ int bl = xstep, b = xstep; double z; - register int i; - + int i; + z = pixvalue(scanline[0], 0, y); if (zline) zline[0] = z; /* zig-zag start for quincunx pattern */ @@ -516,28 +565,30 @@ int xres, y, xstep; } -fillscanbar(scanbar, zbar, xres, y, ysize) /* fill interior */ -register COLOR *scanbar[]; -register float *zbar[]; -int xres, y, ysize; +static void +fillscanbar( /* fill interior */ + COLOR *scanbar[], + float *zbar[], + int xres, + int y, + int ysize +) { COLOR vline[MAXDIV+1]; float zline[MAXDIV+1]; int b = ysize; - register int i, j; - + int i, j; + for (i = 0; i < xres; i++) { - copycolor(vline[0], scanbar[0][i]); copycolor(vline[ysize], scanbar[ysize][i]); if (zbar[0]) { zline[0] = zbar[0][i]; zline[ysize] = zbar[ysize][i]; } - b = fillsample(vline, zbar[0] ? zline : (float *)NULL, i, y, 0, ysize, b/2); - + for (j = 1; j < ysize; j++) copycolor(scanbar[j][i], vline[j]); if (zbar[0]) @@ -547,38 +598,39 @@ int xres, y, ysize; } -int -fillsample(colline, zline, x, y, xlen, ylen, b) /* fill interior points */ -register COLOR *colline; -register float *zline; -int x, y; -int xlen, ylen; -int b; +static int +fillsample( /* fill interior points */ + COLOR *colline, + float *zline, + int x, + int y, + int xlen, + int ylen, + int b +) { double ratio; double z; COLOR ctmp; int ncut; - register int len; - + int len; + if (xlen > 0) /* x or y length is zero */ len = xlen; else len = ylen; - + if (len <= 1) /* limit recursion */ return(0); - - if (b > 0 - || (zline && 2.*fabs(zline[0]-zline[len]) > maxdiff*(zline[0]+zline[len])) + + if (b > 0 || + (zline && 2.*fabs(zline[0]-zline[len]) > maxdiff*(zline[0]+zline[len])) || bigdiff(colline[0], colline[len], maxdiff)) { - + z = pixvalue(colline[len>>1], x + (xlen>>1), y + (ylen>>1)); if (zline) zline[len>>1] = z; ncut = 1; - } else { /* interpolate */ - copycolor(colline[len>>1], colline[len]); ratio = (double)(len>>1) / len; scalecolor(colline[len>>1], ratio); @@ -592,7 +644,7 @@ int b; } /* recurse */ ncut += fillsample(colline, zline, x, y, xlen>>1, ylen>>1, (b-1)/2); - + ncut += fillsample(colline+(len>>1), zline ? zline+(len>>1) : (float *)NULL, x+(xlen>>1), y+(ylen>>1), @@ -602,34 +654,95 @@ int b; } -double -pixvalue(col, x, y) /* compute pixel value */ -COLOR col; /* returned color */ -int x, y; /* pixel position */ +static double +pixvalue( /* compute pixel value */ + COLOR col, /* returned color */ + int x, /* pixel position */ + int y +) { - static RAY thisray; - - if ((thisray.rmax = viewray(thisray.rorg, thisray.rdir, &ourview, - (x+pixjitter())/hres, (y+pixjitter())/vres)) < -FTINY) { - setcolor(col, 0.0, 0.0, 0.0); + extern void SDsquare2disk(double ds[2], double seedx, double seedy); + RAY thisray; + FVECT lorg, ldir; + double hpos, vpos, vdist, lmax; + int i; + /* compute view ray */ + setcolor(col, 0.0, 0.0, 0.0); + hpos = (x+pixjitter())/hres; + vpos = (y+pixjitter())/vres; + if ((thisray.rmax = viewray(thisray.rorg, thisray.rdir, + &ourview, hpos, vpos)) < -FTINY) return(0.0); - } - rayorigin(&thisray, NULL, PRIMARY, 1.0); + vdist = ourview.vdist; + /* set pixel index */ + samplendx = pixnumber(x,y,hres,vres); + /* optional motion blur */ + if (lastview.type && mblur > FTINY && (lmax = viewray(lorg, ldir, + &lastview, hpos, vpos)) >= -FTINY) { + double d = mblur*(.5-urand(281+samplendx)); - samplendx = pixnumber(x,y,hres,vres); /* set pixel index */ + thisray.rmax = (1.-d)*thisray.rmax + d*lmax; + for (i = 3; i--; ) { + thisray.rorg[i] = (1.-d)*thisray.rorg[i] + d*lorg[i]; + thisray.rdir[i] = (1.-d)*thisray.rdir[i] + d*ldir[i]; + } + if (normalize(thisray.rdir) == 0.0) + return(0.0); + vdist = (1.-d)*vdist + d*lastview.vdist; + } + /* optional depth-of-field */ + if (dblur > FTINY) { + double vc, df[2]; + /* random point on disk */ + SDsquare2disk(df, frandom(), frandom()); + df[0] *= .5*dblur; + df[1] *= .5*dblur; + if ((ourview.type == VT_PER) | (ourview.type == VT_PAR)) { + double adj = 1.0; + if (ourview.type == VT_PER) + adj /= DOT(thisray.rdir, ourview.vdir); + df[0] /= sqrt(ourview.hn2); + df[1] /= sqrt(ourview.vn2); + for (i = 3; i--; ) { + vc = ourview.vp[i] + adj*vdist*thisray.rdir[i]; + thisray.rorg[i] += df[0]*ourview.hvec[i] + + df[1]*ourview.vvec[i] ; + thisray.rdir[i] = vc - thisray.rorg[i]; + } + } else { /* non-standard view case */ + double dfd = PI/4.*dblur*(.5 - frandom()); + if ((ourview.type != VT_ANG) & (ourview.type != VT_PLS)) { + if (ourview.type != VT_CYL) + df[0] /= sqrt(ourview.hn2); + df[1] /= sqrt(ourview.vn2); + } + for (i = 3; i--; ) { + vc = ourview.vp[i] + vdist*thisray.rdir[i]; + thisray.rorg[i] += df[0]*ourview.hvec[i] + + df[1]*ourview.vvec[i] + + dfd*ourview.vdir[i] ; + thisray.rdir[i] = vc - thisray.rorg[i]; + } + } + if (normalize(thisray.rdir) == 0.0) + return(0.0); + } + rayorigin(&thisray, PRIMARY, NULL, NULL); + rayvalue(&thisray); /* trace ray */ copycolor(col, thisray.rcol); /* return color */ - + return(thisray.rt); /* return distance */ } -int -salvage(oldfile) /* salvage scanlines from killed program */ -char *oldfile; +static int +salvage( /* salvage scanlines from killed program */ + char *oldfile +) { COLR *scanline; FILE *fp; @@ -643,9 +756,7 @@ char *oldfile; error(WARNING, errmsg); goto gotzip; } -#ifdef MSDOS - setmode(fileno(fp), O_BINARY); -#endif + SET_FILE_BINARY(fp); /* discard header */ getheader(fp, NULL, NULL); /* get picture size */ @@ -657,7 +768,7 @@ char *oldfile; goto gotzip; } - if (x != hres || y != vres) { + if ((x != hres) | (y != vres)) { sprintf(errmsg, "resolution mismatch in recover file \"%s\"", oldfile); error(USER, errmsg); @@ -674,7 +785,7 @@ char *oldfile; } if (fflush(stdout) == EOF) goto writerr; - free((char *)scanline); + free((void *)scanline); fclose(fp); unlink(oldfile); return(y); @@ -685,16 +796,25 @@ gotzip: writerr: sprintf(errmsg, "write error during recovery of \"%s\"", oldfile); error(SYSTEM, errmsg); + return -1; /* pro forma return */ } - -int -pixnumber(x, y, xres, yres) /* compute pixel index (brushed) */ -register int x, y; -int xres, yres; +static int +pixnumber( /* compute pixel index (screen door) */ + int x, + int y, + int xres, + int yres +) { - x -= y; - while (x < 0) - x += xres; - return((((x>>2)*yres + y) << 2) + (x & 3)); + unsigned nbits = 0; + bitmask_t coord[2]; + + if (xres < yres) xres = yres; + while (xres > 0) { + xres >>= 1; + ++nbits; + } + coord[0] = x; coord[1] = y; + return ((int)hilbert_c2i(2, nbits, coord)); }