size_t total[2];
/* This allows limited frequency analysis. */
unsigned buckets, step_bits;
- size_t counts[1 /* [buckets] */ ];
+ size_t counts[1 /* Actually: [buckets] */ ];
};
struct tally *tally_new(unsigned buckets)
{
struct tally *tally;
+ /* There is always 1 bucket. */
+ if (buckets == 0)
+ buckets = 1;
+
/* Check for overflow. */
if (buckets && SIZE_MAX / buckets < sizeof(tally->counts[0]))
return NULL;
- tally = malloc(sizeof(*tally) + sizeof(tally->counts[0])*buckets);
+ tally = malloc(sizeof(*tally) + sizeof(tally->counts[0])*(buckets-1));
if (tally) {
tally->max = ((size_t)1 << (SIZET_BITS - 1));
tally->min = ~tally->max;
tally->total[0] = tally->total[1] = 0;
- /* There is always 1 bucket. */
- tally->buckets = buckets+1;
+ tally->buckets = buckets;
tally->step_bits = 0;
- memset(tally->counts, 0, sizeof(tally->counts[0])*(buckets+1));
+ memset(tally->counts, 0, sizeof(tally->counts[0])*buckets);
}
return tally;
}
}
/* If result is negative, make sure we can represent it. */
- if (tally->total[1] & (1 << (SIZET_BITS-1))) {
+ if (tally->total[1] & ((size_t)1 << (SIZET_BITS-1))) {
/* Must have only underflowed once, and must be able to
* represent result at ssize_t. */
if ((~tally->total[1])+1 != 0
} else {
/* We create a temporary then renormalize so < height. */
/* FIXME: Antialias properly! */
- tmp = tally_new(tally->buckets-1);
+ tmp = tally_new(tally->buckets);
if (!tmp)
return NULL;
tmp->min = tally->min;
}
for (i = 0; i < height; i++) {
- unsigned covered = 1;
- count = (double)tally->counts[i] / largest_bucket * (width-1)+1;
+ unsigned covered = 1, row;
+
+ /* People expect minimum at the bottom. */
+ row = height - i - 1;
+ count = (double)tally->counts[row] / largest_bucket * (width-1)+1;
- if (i == 0)
+ if (row == 0)
covered = snprintf(p, width, "%zi", tally->min);
- else if (i == height - 1)
+ else if (row == height - 1)
covered = snprintf(p, width, "%zi", tally->max);
- else if (i == bucket_of(tally->min, tally->step_bits, 0))
+ else if (row == bucket_of(tally->min, tally->step_bits, 0))
*p = '+';
else
*p = '|';