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-rw-r--r--src/libsystemd-terminal/unifont.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/src/libsystemd-terminal/unifont.c b/src/libsystemd-terminal/unifont.c
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index 0000000000..9e0f718665
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+++ b/src/libsystemd-terminal/unifont.c
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+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+/*
+ * Unifont
+ * This implements the unifont glyph-array parser and provides it via a simple
+ * API to the caller. No heavy transformations are performed so glyph-lookups
+ * stay as fast as possible.
+ */
+
+#include <endian.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "macro.h"
+#include "unifont-def.h"
+#include "unifont-internal.h"
+#include "util.h"
+
+struct unifont {
+ unsigned long ref;
+
+ int fd;
+ const uint8_t *map;
+ size_t size;
+
+ unifont_header header;
+ const void *glyphs; /* unaligned! */
+ size_t n_glyphs;
+ size_t glyphsize;
+};
+
+static int unifont_fetch_header(unifont *u) {
+ unifont_header h = { };
+ uint64_t glyphsize;
+
+ if (u->size < UNIFONT_HEADER_SIZE_MIN)
+ return -EBFONT;
+
+ assert_cc(sizeof(h) >= UNIFONT_HEADER_SIZE_MIN);
+ memcpy(&h, u->map, UNIFONT_HEADER_SIZE_MIN);
+
+ h.compatible_flags = le32toh(h.compatible_flags);
+ h.incompatible_flags = le32toh(h.incompatible_flags);
+ h.header_size = le32toh(h.header_size);
+ h.glyph_header_size = le16toh(h.glyph_header_size);
+ h.glyph_stride = le16toh(h.glyph_stride);
+ h.glyph_body_size = le64toh(h.glyph_body_size);
+
+ if (memcmp(h.signature, "DVDHRMUF", 8))
+ return -EBFONT;
+ if (h.incompatible_flags != 0)
+ return -EBFONT;
+ if (h.header_size < UNIFONT_HEADER_SIZE_MIN || h.header_size > u->size)
+ return -EBFONT;
+ if (h.glyph_header_size + h.glyph_body_size < h.glyph_header_size)
+ return -EBFONT;
+ if (h.glyph_stride * 16ULL > h.glyph_body_size)
+ return -EBFONT;
+
+ glyphsize = h.glyph_header_size + h.glyph_body_size;
+
+ if (glyphsize == 0 || glyphsize > u->size - h.header_size) {
+ u->n_glyphs = 0;
+ } else {
+ u->glyphs = u->map + h.header_size;
+ u->n_glyphs = (u->size - h.header_size) / glyphsize;
+ u->glyphsize = glyphsize;
+ }
+
+ memcpy(&u->header, &h, sizeof(h));
+ return 0;
+}
+
+static int unifont_fetch_glyph(unifont *u, unifont_glyph_header *out_header, const void **out_body, uint32_t ucs4) {
+ unifont_glyph_header glyph_header = { };
+ const void *glyph_body = NULL;
+ const uint8_t *p;
+
+ if (ucs4 >= u->n_glyphs)
+ return -ENOENT;
+
+ p = u->glyphs;
+
+ /* copy glyph-header data */
+ p += ucs4 * u->glyphsize;
+ memcpy(&glyph_header, p, MIN(sizeof(glyph_header), u->header.glyph_header_size));
+
+ /* copy glyph-body pointer */
+ p += u->header.glyph_header_size;
+ glyph_body = p;
+
+ if (glyph_header.width < 1)
+ return -ENOENT;
+ if (glyph_header.width > u->header.glyph_stride)
+ return -EBFONT;
+
+ memcpy(out_header, &glyph_header, sizeof(glyph_header));
+ *out_body = glyph_body;
+ return 0;
+}
+
+int unifont_new(unifont **out) {
+ _cleanup_(unifont_unrefp) unifont *u = NULL;
+ struct stat st;
+ int r;
+
+ assert_return(out, -EINVAL);
+
+ u = new0(unifont, 1);
+ if (!u)
+ return -ENOMEM;
+
+ u->ref = 1;
+ u->fd = -1;
+ u->map = MAP_FAILED;
+
+ u->fd = open(UNIFONT_PATH, O_RDONLY | O_CLOEXEC | O_NOCTTY);
+ if (u->fd < 0)
+ return -errno;
+
+ r = fstat(u->fd, &st);
+ if (r < 0)
+ return -errno;
+
+ u->size = st.st_size;
+ u->map = mmap(NULL, u->size, PROT_READ, MAP_PRIVATE, u->fd, 0);
+ if (u->map == MAP_FAILED)
+ return -errno;
+
+ r = unifont_fetch_header(u);
+ if (r < 0)
+ return r;
+
+ *out = u;
+ u = NULL;
+ return 0;
+}
+
+unifont *unifont_ref(unifont *u) {
+ if (!u || !u->ref)
+ return NULL;
+
+ ++u->ref;
+
+ return u;
+}
+
+unifont *unifont_unref(unifont *u) {
+ if (!u || !u->ref || --u->ref)
+ return NULL;
+
+ if (u->map != MAP_FAILED)
+ munmap((void*)u->map, u->size);
+ u->fd = safe_close(u->fd);
+ free(u);
+
+ return NULL;
+}
+
+unsigned int unifont_get_stride(unifont *u) {
+ assert(u);
+
+ return u->header.glyph_stride;
+}
+
+int unifont_lookup(unifont *u, unifont_glyph *out, uint32_t ucs4) {
+ unifont_glyph_header h = { };
+ const void *b = NULL;
+ unifont_glyph g = { };
+ int r;
+
+ assert_return(u, -EINVAL);
+
+ r = unifont_fetch_glyph(u, &h, &b, ucs4);
+ if (r < 0)
+ return r;
+
+ g.width = h.width * 8U;
+ g.height = 16U;
+ g.stride = u->header.glyph_stride;
+ g.cwidth = h.width;
+ g.data = b;
+
+ if (out)
+ memcpy(out, &g, sizeof(g));
+ return 0;
+}