Files
cosmopolitan/third_party/avir/lanczos1.cc
Justine Tunney ea0b5d9d1c Get Cosmopolitan into releasable state
A new rollup tool now exists for flattening out the headers in a way
that works better for our purposes than cpp. A lot of the API clutter
has been removed. APIs that aren't a sure thing in terms of general
recommendation are now marked internal.

There's now a smoke test for the amalgamation archive and gigantic
header file. So we can now guarantee you can use this project on the
easiest difficulty setting without the gigantic repository.

A website is being created, which is currently a work in progress:
https://justine.storage.googleapis.com/cosmopolitan/index.html
2020-11-25 08:19:00 -08:00

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/*-*-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/limits.h"
#include "libc/log/log.h"
#include "libc/runtime/runtime.h"
#include "third_party/avir/lanczos1.h"
namespace {
#include "third_party/avir/lanczos1.hpp"
} // namespace
void lanczos1init(struct lanczos1 *resizer) {
lanczos1free(resizer);
resizer->p = new Lanczos1Impl;
}
void lanczos1free(struct lanczos1 *resizer) {
Lanczos1Impl *impl;
if (!resizer->p) return;
impl = (Lanczos1Impl *)resizer->p;
delete impl;
resizer->p = nullptr;
}
/**
* Resizes image plane w/ Lanczos interpolation, e.g.
*
* struct lanczos1 scaler = {0};
* lanczos1init(&scaler);
* lanczos1(&scaler, ...);
* lanczos1free(&scaler);
*
* @param dyn is destination height
* @param dxn is destination width
* @param dst is destination unsigned char array
* @param dstsize is number of bytes in dst
* @param syn is source height
* @param sxn is source width
* @param ssw is number of unsigned chars per scanline in src
* @param src is source unsigned char array
* @param srcsize is number of bytes in src
*/
void lanczos1(struct lanczos1 *resizer, size_t dyn, size_t dxn, void *dst,
size_t dstsize, size_t syn, size_t sxn, size_t ssw,
const void *src, size_t srcsize) {
Lanczos1Impl *impl;
unsigned int roundhouse;
LOGF("%10s%5zux×%-5zu→%5zu×%-5zu", "lanczos1", sxn, syn, dxn, dyn);
CHECK_LE(dstsize, INT_MAX);
CHECK_LE(srcsize, INT_MAX);
CHECK_LE(sizeof(unsigned char) * 1 * dyn * dxn, dstsize);
CHECK_LE(sizeof(unsigned char) * 1 * syn * sxn, srcsize);
CHECK_LE(sizeof(unsigned char) * syn * ssw, srcsize);
roundhouse = _MM_GET_ROUNDING_MODE();
_MM_SET_ROUNDING_MODE(_MM_ROUND_NEAREST);
impl = (Lanczos1Impl *)resizer->p;
impl->lanczos.resizeImage((const unsigned char *)src, sxn, syn, ssw,
(unsigned char *)dst, dxn, dyn, 1);
_MM_SET_ROUNDING_MODE(roundhouse);
}