1 files changed, 44 insertions, 0 deletions
diff --git a/libparsepcf_get_encoding.c b/libparsepcf_get_encoding.c
new file mode 100644
index 0000000..34ccd9b
--- /dev/null
+++ b/libparsepcf_get_encoding.c
@@ -0,0 +1,44 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+int
+libparsepcf_get_encoding(const char *file, size_t size,
+                         const struct libparsepcf_table *table,
+                         struct libparsepcf_encoding *out)
+{
+	int msb = table->format & LIBPARSEPCF_BYTE;
+	size_t pos;
+
+	(void) size;
+
+	if (table->size < 14)
+		goto ebfont;
+
+	pos = table->offset;
+
+	if (table->format != libparsepcf_parse_lsb_uint32__(&file[pos]))
+		goto ebfont;
+	pos += 4;
+
+	out->min_byte2 = PARSE_UINT16(&file[pos + 0], msb);
+	out->max_byte2 = PARSE_UINT16(&file[pos + 2], msb);
+	out->min_byte1 = PARSE_UINT16(&file[pos + 4], msb);
+	out->max_byte1 = PARSE_UINT16(&file[pos + 6], msb);
+	out->default_char = PARSE_UINT16(&file[pos + 8], msb);
+	pos += 10;
+
+	if (out->min_byte2 > out->max_byte2 || out->max_byte2 > 255 ||
+	    out->min_byte1 > out->max_byte1 || out->max_byte1 > 255)
+		goto ebfont;
+
+	out->glyph_count = (size_t)(out->max_byte2 - out->min_byte2 + 1) * (size_t)(out->max_byte1 - out->min_byte1 + 1);
+	if (out->glyph_count > table->size - (pos - table->offset) / 2)
+		goto ebfont;
+
+	return 0;
+
+ebfont:
+	errno = EBFONT;
+	return -1;
+}