cosmopolitan/dsp/tty/ttyhisto.c

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2020-06-15 14:18:57 +00:00
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "dsp/tty/tty.h"
#include "libc/alg/alg.h"
#include "libc/nexgen32e/nexgen32e.h"
#include "libc/str/str.h"
static int histcmp(const uint8_t *i1p, const uint8_t *i2p,
uint32_t histogram[hasatleast 256]) {
if (histogram[*i1p] > histogram[*i2p]) {
return -1;
} else if (histogram[*i1p] < histogram[*i2p]) {
return 1;
} else {
return 0;
}
}
void ttyhisto(uint32_t histogram[hasatleast 256],
uint8_t dominant[hasatleast 256], const uint8_t *xtcolors,
const uint8_t *eqmask, size_t size) {
size_t i;
uint64_t q;
memset(histogram, 0, sizeof(uint32_t) * 256);
for (i = 0; i < size / 8; ++i) {
memcpy(&q, &xtcolors[i * 8], 8);
if (q == (xtcolors[i * 8] & 0xff) * 0x0101010101010101ul) {
histogram[xtcolors[i * 8]]++;
}
}
imapxlatab(dominant);
qsort_r(dominant, 256, 1, (void *)histcmp, histogram);
}