diff options
Diffstat (limited to 'bin/fbclock.c')
| -rw-r--r-- | bin/fbclock.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/bin/fbclock.c b/bin/fbclock.c new file mode 100644 index 00000000..ddc32db6 --- /dev/null +++ b/bin/fbclock.c @@ -0,0 +1,132 @@ +/* Copyright (C) 2018 C. McEnroe <june@causal.agency> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <assert.h> +#include <err.h> +#include <fcntl.h> +#include <linux/fb.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sysexits.h> +#include <time.h> +#include <unistd.h> +#include <zlib.h> + +#include "scheme.h" + +static const uint32_t PSF2Magic = 0x864AB572; +struct PSF2Header { + uint32_t magic; + uint32_t version; + uint32_t headerSize; + uint32_t flags; + uint32_t glyphCount; + uint32_t glyphSize; + uint32_t glyphHeight; + uint32_t glyphWidth; +}; + +int main() { + size_t len; + + const char *fontPath = getenv("FONT"); + if (!fontPath) { + fontPath = "/usr/share/kbd/consolefonts/Lat2-Terminus16.psfu.gz"; + } + + gzFile font = gzopen(fontPath, "r"); + if (!font) err(EX_NOINPUT, "%s", fontPath); + + struct PSF2Header header; + len = gzfread(&header, sizeof(header), 1, font); + if (!len && gzeof(font)) errx(EX_DATAERR, "%s: missing header", fontPath); + if (!len) errx(EX_IOERR, "%s", gzerror(font, NULL)); + + if (header.magic != PSF2Magic) { + errx( + EX_DATAERR, "%s: invalid header magic %08X", + fontPath, header.magic + ); + } + if (header.headerSize != sizeof(struct PSF2Header)) { + errx( + EX_DATAERR, "%s: weird header size %d", + fontPath, header.headerSize + ); + } + + uint8_t glyphs[128][header.glyphSize]; + len = gzfread(glyphs, header.glyphSize, 128, font); + if (!len && gzeof(font)) errx(EX_DATAERR, "%s: missing glyphs", fontPath); + if (!len) errx(EX_IOERR, "%s", gzerror(font, NULL)); + + gzclose(font); + + const char *fbPath = getenv("FRAMEBUFFER"); + if (!fbPath) fbPath = "/dev/fb0"; + + int fb = open(fbPath, O_RDWR); + if (fb < 0) err(EX_OSFILE, "%s", fbPath); + + struct fb_var_screeninfo info; + int error = ioctl(fb, FBIOGET_VSCREENINFO, &info); + if (error) err(EX_IOERR, "%s", fbPath); + + size_t size = 4 * info.xres * info.yres; + uint32_t *buf = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fb, 0); + if (buf == MAP_FAILED) err(EX_IOERR, "%s", fbPath); + + for (;;) { + time_t t = time(NULL); + if (t < 0) err(EX_OSERR, "time"); + const struct tm *local = localtime(&t); + if (!local) err(EX_OSERR, "localtime"); + + char str[64]; + len = strftime(str, sizeof(str), "%H:%M", local); + assert(len); + + for (int i = 0; i < (60 - local->tm_sec); ++i, sleep(1)) { + uint32_t left = info.xres - header.glyphWidth * len; + uint32_t bottom = header.glyphHeight; + + for (uint32_t y = 0; y < bottom; ++y) { + buf[y * info.xres + left - 1] = DarkWhite; + } + for (uint32_t x = left - 1; x < info.xres; ++x) { + buf[bottom * info.xres + x] = DarkWhite; + } + + for (const char *s = str; *s; ++s) { + const uint8_t *glyph = glyphs[(unsigned)*s]; + uint32_t stride = header.glyphSize / header.glyphHeight; + for (uint32_t y = 0; y < header.glyphHeight; ++y) { + for (uint32_t x = 0; x < header.glyphWidth; ++x) { + uint8_t bits = glyph[y * stride + x / 8]; + uint8_t bit = bits >> (7 - x % 8) & 1; + buf[y * info.xres + left + x] = bit + ? DarkWhite + : DarkBlack; + } + } + left += header.glyphWidth; + } + } + } +} |