Add hdmx

Signed-off-by: Mattias Andrée <maandree@kth.se>

3 files changed, 126 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 11982d0..874f5ec 100644
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,8 @@ MODULES =\
 	fdsc\
 	gasp\
 	avar\
-	meta
+	meta\
+	hdmx
 
 OBJ =\
 	libparsesfnt_parse___.o\
diff --git a/hdmx.c b/hdmx.c
new file mode 100644
index 0000000..0fefa12
--- /dev/null
+++ b/hdmx.c
@@ -0,0 +1,89 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+int
+libparsesfnt_parse_hdmx(
+			const char *data, size_t size,
+			struct libparsesfnt_hdmx *infop,
+			const struct libparsesfnt_tabdir_entry *tag)
+{
+	int ret;
+	ret = PARSE(LIBPARSESFNT_HDMX__, tag->offset, 0, 0, 0, 1, tag);
+	if (!ret) {
+		if (!infop->record_size ||
+		    (size_t)infop->num_records > (size_t)tag->length / (size_t)infop->record_size) {
+			errno = EBFONT;
+			return -1;
+		}
+	}
+	return ret;
+}
+
+
+int
+libparsesfnt_parse_hdmx_entries(
+			const char *data, size_t size,
+			struct libparsesfnt_hdmx_v0_entry *infop,
+			const struct libparsesfnt_tabdir_entry *tag, const struct libparsesfnt_hdmx *hdmx,
+			size_t first, size_t count)
+{
+	size_t off;
+
+	off = tag->offset;
+	if (off > size || 8 > size - off || hdmx->record_size < 2)
+		goto ebfont;
+	off += 8;
+	if (first > (size - off) / hdmx->record_size)
+		goto ebfont;
+	off += hdmx->record_size * first;
+	if (count > (size - off) / hdmx->record_size)
+		goto ebfont;
+
+	data = &data[off];
+	for (; count--; infop++) {
+		infop->pixel_size = ((const uint8_t *)data)[0];
+		infop->maximum_width = ((const uint8_t *)data)[1];
+		data = &data[2];
+	}
+
+	return 0;
+
+ebfont:
+	errno = EBFONT;
+	return -1;
+}
+
+
+int
+libparsesfnt_parse_hdmx_v0_subentry(
+	const char *data, size_t size,
+	uint8_t *widthp,
+	const struct libparsesfnt_tabdir_entry *tag, const struct libparsesfnt_hdmx *hdmx, size_t record,
+	size_t first, size_t count)
+{
+	size_t off;
+
+	off = tag->offset;
+	if (off > size || 10 > size - off)
+		goto ebfont;
+	off += 10;
+	if (record > (size - off) / hdmx->record_size)
+		goto ebfont;
+	off += hdmx->record_size * record;
+	if (first > size - off)
+		goto ebfont;
+	off += first;
+	if (count > size - off)
+		goto ebfont;
+
+	if (2 > hdmx->record_size || first + count > hdmx->record_size - 2)
+		goto ebfont;
+
+	memcpy(widthp, &data[off], count);
+	return 0;
+
+ebfont:
+	errno = EBFONT;
+	return -1;
+}
diff --git a/libparsesfnt.h b/libparsesfnt.h
index 809fad7..f79ed03 100644
--- a/libparsesfnt.h
+++ b/libparsesfnt.h
@@ -768,4 +768,39 @@ int libparsesfnt_parse_meta_entries(
 	size_t first, size_t count);
 
 
+
+/* === 'hdmx' (horizontal device metrics) === */
+/* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6hdmx.html */
+
+struct libparsesfnt_hdmx {
+	uint16_t version;
+	uint16_t num_records;
+	uint32_t record_size; /* includes alignment */
+};
+#define LIBPARSESFNT_HDMX__ "224"
+
+struct libparsesfnt_hdmx_v0_entry {
+	uint8_t pixel_size;
+	uint8_t maximum_width;
+};
+#define LIBPARSESFNT_HDMX_V0_ENTRY__ "11"
+
+int libparsesfnt_parse_hdmx(
+	const char *data, size_t size,
+	struct libparsesfnt_hdmx *infop,
+	const struct libparsesfnt_tabdir_entry *tag);
+
+int libparsesfnt_parse_hdmx_v0_entries(
+	const char *data, size_t size,
+	struct libparsesfnt_hdmx_v0_entry *infop,
+	const struct libparsesfnt_tabdir_entry *tag, const struct libparsesfnt_hdmx *hdmx,
+	size_t first, size_t count);
+
+int libparsesfnt_parse_hdmx_v0_subentry(
+	const char *data, size_t size,
+	uint8_t *widthp,
+	const struct libparsesfnt_tabdir_entry *tag, const struct libparsesfnt_hdmx *hdmx, size_t record,
+	size_t first, size_t count);
+
+
 #endif