cosmopolitan/tool/viz/lib/halfblit.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 "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;
}