First cut - beautiful new font handling by PetteriAimonen

1 files changed, 69 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..4e3975ae
--- /dev/null
+++ b/src/gdisp/mcufont/mf_encoding.c
@@ -0,0 +1,69 @@
+#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)--;
+}
+
+#endif