cosmopolitan/tool/viz/lib/gaussian.c

72 lines
3.2 KiB
C

/*-*- 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 "libc/bits/xmmintrin.internal.h"
#include "libc/macros.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
#include "tool/viz/lib/convolution.h"
#include "tool/viz/lib/graphic.h"
/**
* Blurs image.
* @see https://en.wikipedia.org/wiki/Kernel_(image_processing)
*/
long gaussian(long yn, long xn, unsigned char img[3][yn][xn]) {
#if 0
long rc, c, y, x, b;
unsigned *iy, *ix;
unsigned char(*ta)[3][xn];
iy = convoindex(2, yn, 2);
ix = convoindex(2, xn, 2);
ta = memalign(32, xn * 3);
if (ta && ix && iy) {
iy += 2;
ix += 2;
for (c = 0; c < 3; ++c) {
for (y = 0; y < yn + 3; ++y) {
if (y >= 3) memcpy(img[c][y - 3], (*ta)[y % 3], xn);
if (y < yn) {
for (x = 0; x < xn; ++x) {
b = CONVOLVE5X5(/* clang-format off */
15, (1 / 256.), img[c],
1, 4, 6, 4, 1,
4, 16, 24, 16, 4,
6, 24, 36, 24, 6,
4, 16, 24, 16, 4,
1, 4, 6, 4, 1
/* clang-format on */);
(*ta)[y % 3][x] = MIN(255, MAX(0, b));
}
}
}
}
rc = 0;
} else {
rc = enomem();
}
free(ta);
if (ix) free(ix - 2);
if (iy) free(iy - 2);
return rc;
#endif
return 0;
}