20 |
|
static int |
21 |
|
sum_images(const char *fspec, const CMATRIX *cv, FILE *fout) |
22 |
|
{ |
23 |
+ |
static int runcnt = 0; |
24 |
|
int myDT = DTfromHeader; |
25 |
|
COLR *scanline = NULL; |
26 |
|
CMATRIX *pmat = NULL; |
29 |
|
|
30 |
|
if (cv->ncols != 1) |
31 |
|
error(INTERNAL, "expected vector in sum_images()"); |
32 |
< |
for (i = 0; i < cv->nrows; i++) { |
33 |
< |
const COLORV *scv = cv_lval(cv,i); |
32 |
> |
for (i = cv->nrows; i-- > 0; ) { |
33 |
> |
const int r = runcnt&1 ? i : cv->nrows-1 - i; |
34 |
> |
const COLORV *scv = cv_lval(cv,r); |
35 |
|
int flat_file = 0; |
36 |
|
char fname[1024]; |
37 |
|
FILE *fp; |
41 |
|
char *err; |
42 |
|
/* check for zero */ |
43 |
|
if ((scv[RED] == 0) & (scv[GRN] == 0) & (scv[BLU] == 0) && |
44 |
< |
(myDT != DTfromHeader) | (i < cv->nrows-1)) |
44 |
> |
(myDT != DTfromHeader) | (i > 0)) |
45 |
|
continue; |
46 |
|
/* open next picture */ |
47 |
< |
sprintf(fname, fspec, i); |
47 |
> |
sprintf(fname, fspec, r); |
48 |
|
if ((fp = fopen(fname, "rb")) == NULL) { |
49 |
|
sprintf(errmsg, "cannot open picture '%s'", fname); |
50 |
|
error(SYSTEM, errmsg); |
109 |
|
free(scanline); |
110 |
|
i = cm_write(pmat, myDT, fout); /* write picture */ |
111 |
|
cm_free(pmat); /* free data */ |
112 |
+ |
++runcnt; /* for zig-zagging */ |
113 |
|
return(i); |
114 |
|
} |
115 |
|
|