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/*
* Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Hyra nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <libgfx/draw.h>
#include <libgfx/gfx.h>
static struct gfx_ctx ctx;
static ssize_t
rand_bytes(char *buf, size_t len)
{
ssize_t retval;
int fd;
fd = open("/dev/random", O_RDONLY);
if (fd < 0) {
return fd;
}
if ((retval = read(fd, buf, len)) < 0) {
close(fd);
return retval;
}
close(fd);
return retval;
}
static void
screensave(void)
{
size_t n_iter = 0; /* Monotonic */
struct timespec ts;
char randbuf[2];
color_t curpix, nextpix;
uint8_t step = 0;
ts.tv_sec = 0;
ts.tv_nsec = 3000000;
/* Begin the radiation ::) */
for (;;) {
rand_bytes(randbuf, sizeof(randbuf));
for (size_t i = 0; i < (ctx.fb_size / 4) - 1; i += step + 1) {
curpix = ctx.io[i];
nextpix = ctx.io[i + 1];
/* If a multiple of 16, AND, otherwise XOR */
if ((n_iter & 15) != 0) {
curpix ^= randbuf[0] & 3;
nextpix ^= (curpix | (nextpix << 1));
nextpix ^= step;
} else {
curpix &= randbuf[0] & 3;
nextpix &= (curpix | (nextpix << 1));
nextpix &= step;
}
ctx.io[i] = curpix;
ctx.io[i + 1] = nextpix;
}
sleep(&ts, &ts);
if ((++step) > 50) {
step = 0;
}
++n_iter;
}
}
int
main(void)
{
int error;
error = gfx_init(&ctx);
if (error < 0) {
printf("could not init libgfx\n");
return error;
}
screensave();
gfx_cleanup(&ctx);
return 0;
}
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