aboutsummaryrefslogtreecommitdiffstats
path: root/src/gdisp/mcufont/mf_encoding.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/gdisp/mcufont/mf_encoding.c')
-rw-r--r--src/gdisp/mcufont/mf_encoding.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/src/gdisp/mcufont/mf_encoding.c b/src/gdisp/mcufont/mf_encoding.c
new file mode 100644
index 00000000..2c8abf3a
--- /dev/null
+++ b/src/gdisp/mcufont/mf_encoding.c
@@ -0,0 +1,86 @@
+/*
+ * This file is subject to the terms of the GFX License. If a copy of
+ * the license was not distributed with this file, you can obtain one at:
+ *
+ * http://ugfx.org/license.html
+ */
+
+#include "mf_encoding.h"
+
+#if MF_ENCODING == MF_ENCODING_UTF8
+
+mf_char mf_getchar(mf_str *str)
+{
+ uint8_t c;
+ uint8_t tmp, seqlen;
+ uint16_t result;
+
+ c = **str;
+ if (!c)
+ return 0;
+
+ (*str)++;
+
+ if ((c & 0x80) == 0)
+ {
+ /* Just normal ASCII character. */
+ return c;
+ }
+ else if ((c & 0xC0) == 0x80)
+ {
+ /* Dangling piece of corrupted multibyte sequence.
+ * Did you cut the string in the wrong place?
+ */
+ return c;
+ }
+ else if ((**str & 0xC0) == 0xC0)
+ {
+ /* Start of multibyte sequence without any following bytes.
+ * Silly. Maybe you are using the wrong encoding.
+ */
+ return c;
+ }
+ else
+ {
+ /* Beginning of a multi-byte sequence.
+ * Find out how many characters and combine them.
+ */
+ seqlen = 2;
+ tmp = 0x20;
+ result = 0;
+ while ((c & tmp) && (seqlen < 5))
+ {
+ seqlen++;
+ tmp >>= 1;
+
+ result = (result << 6) | (**str & 0x3F);
+ (*str)++;
+ }
+
+ result = (result << 6) | (**str & 0x3F);
+ (*str)++;
+
+ result |= (c & (tmp - 1)) << ((seqlen - 1) * 6);
+ return result;
+ }
+}
+
+void mf_rewind(mf_str *str)
+{
+ (*str)--;
+
+ while ((**str & 0x80) != 0x00 && (**str & 0xC0) != 0xC0)
+ (*str)--;
+}
+
+#else
+
+mf_char mf_getchar(mf_str *str) {
+ return *(*str)++;
+}
+
+void mf_rewind(mf_str *str) {
+ (*str)--;
+}
+
+#endif