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-rw-r--r--bin/fbclock.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/bin/fbclock.c b/bin/fbclock.c
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+++ b/bin/fbclock.c
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+/* Copyright (C) 2018  June 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;
+			}
+		}
+	}
+}