| 70 |
|
|
| 71 |
|
extern long nrays; /* number of rays traced */ |
| 72 |
|
|
| 73 |
< |
#define MAXDIV 15 /* maximum sample size */ |
| 73 |
> |
#define MAXDIV 16 /* maximum sample size */ |
| 74 |
|
|
| 75 |
|
#define pixjitter() (.5+dstrpix*(.5-frandom())) |
| 76 |
|
|
| 123 |
|
extern long lseek(); |
| 124 |
|
COLOR *scanbar[MAXDIV+1]; /* scanline arrays of pixel values */ |
| 125 |
|
float *zbar[MAXDIV+1]; /* z values */ |
| 126 |
+ |
char *sampdens; /* previous sample density */ |
| 127 |
|
int ypos; /* current scanline */ |
| 128 |
|
int ystep; /* current y step size */ |
| 129 |
|
int hstep; /* h step size */ |
| 146 |
|
if (scanbar[i] == NULL) |
| 147 |
|
goto memerr; |
| 148 |
|
} |
| 149 |
+ |
hstep = (psample*140+49)/99; /* quincunx sampling */ |
| 150 |
+ |
ystep = (psample*99+70)/140; |
| 151 |
+ |
if (hstep > 2) { |
| 152 |
+ |
i = hresolu/hstep + 2; |
| 153 |
+ |
if ((sampdens = malloc(i)) == NULL) |
| 154 |
+ |
goto memerr; |
| 155 |
+ |
while (i--) |
| 156 |
+ |
sampdens[i] = hstep; |
| 157 |
+ |
} else |
| 158 |
+ |
sampdens = NULL; |
| 159 |
|
/* open z file */ |
| 160 |
|
if (zfile != NULL) { |
| 161 |
|
if ((zfd = open(zfile, O_WRONLY|O_CREAT, 0666)) == -1) { |
| 187 |
|
#endif |
| 188 |
|
signal(SIGALRM, report); |
| 189 |
|
ypos = vresolu-1 - i; |
| 190 |
< |
hstep = (psample*140+49)/99; /* quincunx sampling */ |
| 180 |
< |
ystep = (psample*99+70)/140; |
| 181 |
< |
fillscanline(scanbar[0], zbar[0], hresolu, ypos, hstep); |
| 190 |
> |
fillscanline(scanbar[0], zbar[0], sampdens, hresolu, ypos, hstep); |
| 191 |
|
/* compute scanlines */ |
| 192 |
|
for (ypos -= ystep; ypos > -ystep; ypos -= ystep) { |
| 193 |
|
/* bottom adjust? */ |
| 202 |
|
zbar[ystep] = zbar[0]; |
| 203 |
|
zbar[0] = zptr; |
| 204 |
|
/* fill base line */ |
| 205 |
< |
fillscanline(scanbar[0], zbar[0], hresolu, ypos, hstep); |
| 205 |
> |
fillscanline(scanbar[0], zbar[0], sampdens, |
| 206 |
> |
hresolu, ypos, hstep); |
| 207 |
|
/* fill bar */ |
| 208 |
|
fillscanbar(scanbar, zbar, hresolu, ypos, ystep); |
| 209 |
|
/* write it out */ |
| 244 |
|
goto writerr; |
| 245 |
|
for (i = 0; i <= psample; i++) |
| 246 |
|
free((char *)scanbar[i]); |
| 247 |
+ |
if (sampdens != NULL) |
| 248 |
+ |
free(sampdens); |
| 249 |
|
pctdone = 100.0; |
| 250 |
|
return; |
| 251 |
|
writerr: |
| 255 |
|
} |
| 256 |
|
|
| 257 |
|
|
| 258 |
< |
fillscanline(scanline, zline, xres, y, xstep) /* fill scan line at y */ |
| 258 |
> |
fillscanline(scanline, zline, sd, xres, y, xstep) /* fill scan at y */ |
| 259 |
|
register COLOR *scanline; |
| 260 |
|
register float *zline; |
| 261 |
+ |
register char *sd; |
| 262 |
|
int xres, y, xstep; |
| 263 |
|
{ |
| 264 |
|
static int nc = 0; /* number of calls */ |
| 265 |
< |
int b = xstep; |
| 265 |
> |
int bl = xstep, b = xstep; |
| 266 |
|
double z; |
| 267 |
|
register int i; |
| 268 |
|
|
| 269 |
|
z = pixvalue(scanline[0], 0, y); |
| 270 |
|
if (zline) zline[0] = z; |
| 271 |
|
/* zig-zag start for quincunx pattern */ |
| 272 |
< |
for (i = nc++ & 1 ? xstep/2 : xstep; i < xres-1+xstep; i += xstep) { |
| 272 |
> |
for (i = ++nc & 1 ? xstep : xstep/2; i < xres-1+xstep; i += xstep) { |
| 273 |
|
if (i >= xres) { |
| 274 |
|
xstep += xres-1-i; |
| 275 |
|
i = xres-1; |
| 276 |
|
} |
| 277 |
|
z = pixvalue(scanline[i], i, y); |
| 278 |
|
if (zline) zline[i] = z; |
| 279 |
< |
|
| 279 |
> |
if (sd) b = sd[0] > sd[1] ? sd[0] : sd[1]; |
| 280 |
|
b = fillsample(scanline+i-xstep, zline ? zline+i-xstep : NULL, |
| 281 |
|
i-xstep, y, xstep, 0, b/2); |
| 282 |
+ |
if (sd) *sd++ = nc & 1 ? bl : b; |
| 283 |
+ |
bl = b; |
| 284 |
|
} |
| 285 |
+ |
if (sd && nc & 1) *sd = bl; |
| 286 |
|
} |
| 287 |
|
|
| 288 |
|
|
