cosmopolitan/tool/viz/lib/gaussian.c

71 lines
3.1 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 │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#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;
}