cosmopolitan/tool/viz/lib/halfblit.c

36 lines
2.2 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/log/check.h"
#include "tool/viz/lib/halfblit.h"
void *halfblit(size_t n, void *block) {
unsigned y, x;
char(*dst)[n << 0][n << 0] = block;
char(*src)[n << 1][n << 1] = block;
DCHECK_GE(n, 2);
DCHECK_ALIGNED(16, block);
for (y = 0; y < n; ++y) {
for (x = 0; x < n; ++x) {
(*dst)[y][x] = (*src)[y][x];
}
}
return block;
}