cosmopolitan/test/dsp/core/gamma_test.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 "dsp/core/core.h"
#include "libc/math.h"
#include "libc/testlib/testlib.h"
TEST(gamma, test) {
int i;
double g, x, a, b;
g = 2.4;
for (i = 0; i < 256; ++i) {
x = i;
x /= 255;
a = rgb2stdpc(x, g);
b = tv2pcgamma(rgb2stdtv(x), g);
ASSERT_EQ(true, fabs(a - b) < .000000001, "%d %f %f %f", i, x, a, b);
}
}