39 |
|
static long ncall = 0L; /* number of calls to getpictscan */ |
40 |
|
static long nread = 0L; /* number of scanlines read */ |
41 |
|
|
42 |
+ |
extern long ftell(); |
43 |
|
|
44 |
+ |
|
45 |
|
COLR * |
46 |
|
getpictscan(y) /* get picture scanline */ |
47 |
|
int y; |
48 |
|
{ |
47 |
– |
extern long ftell(); |
49 |
|
int minused; |
50 |
|
register int i; |
51 |
|
/* first check our buffers */ |
60 |
|
minused = i; |
61 |
|
} |
62 |
|
/* not there, read it in */ |
63 |
< |
if (scanpos[y] == -1) { /* need to search */ |
64 |
< |
while (curpos > y) { |
63 |
> |
if (scanpos[y] < 0) { /* need to search */ |
64 |
> |
for (i = y+1; i < curpos; i++) |
65 |
> |
if (scanpos[i] >= 0) { |
66 |
> |
if (fseek(pictfp, scanpos[i], 0) < 0) |
67 |
> |
goto seekerr; |
68 |
> |
curpos = i; |
69 |
> |
break; |
70 |
> |
} |
71 |
> |
while (curpos >= y) { |
72 |
|
scanpos[curpos] = ftell(pictfp); |
73 |
|
if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0) |
74 |
|
goto readerr; |
75 |
+ |
nread++; |
76 |
|
curpos--; |
77 |
|
} |
78 |
< |
} else if (fseek(pictfp, scanpos[y], 0) < 0) { |
79 |
< |
fprintf(stderr, "%s: picture seek error\n", progname); |
80 |
< |
exit(1); |
78 |
> |
} else { |
79 |
> |
if (curpos != y && fseek(pictfp, scanpos[y], 0) < 0) |
80 |
> |
goto seekerr; |
81 |
> |
if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0) |
82 |
> |
goto readerr; |
83 |
> |
nread++; |
84 |
> |
curpos = y-1; |
85 |
|
} |
73 |
– |
if (freadcolrs(scan[minused].sl, pxsiz, pictfp) < 0) |
74 |
– |
goto readerr; |
75 |
– |
nread++; |
76 |
– |
curpos = y-1; |
86 |
|
scan[minused].lused = ncall; |
87 |
|
scan[minused].y = y; |
88 |
|
return(scan[minused].sl); |
89 |
|
readerr: |
90 |
|
fprintf(stderr, "%s: picture read error\n", progname); |
91 |
|
exit(1); |
92 |
+ |
seekerr: |
93 |
+ |
fprintf(stderr, "%s: picture seek error\n", progname); |
94 |
+ |
exit(1); |
95 |
|
} |
96 |
|
|
97 |
|
|
259 |
|
scanpos = (long *)malloc(pysiz*sizeof(long)); |
260 |
|
if (scanpos == NULL) |
261 |
|
memerr("scanline positions"); |
262 |
< |
for (i = 0; i < pysiz; i++) |
262 |
> |
for (i = pysiz-1; i >= 0; i--) |
263 |
|
scanpos[i] = -1L; |
264 |
+ |
curpos = pysiz-1; |
265 |
|
for (i = 0; i < NSCANS; i++) { |
266 |
|
scan[i].lused = -1; |
267 |
|
scan[i].y = -1; |
269 |
|
if (scan[i].sl == NULL) |
270 |
|
memerr("scanline buffers"); |
271 |
|
} |
259 |
– |
curpos = pysiz-1; |
272 |
|
} |
273 |
|
|
274 |
|
|