move EncodedCharAdjustCounter() to common.[ch] and rename it to encodedCharAdjustCounter()

1 files changed, 57 insertions, 0 deletions

diff --git a/glcdgraphics/common.c b/glcdgraphics/common.c
index 8942424..7bfcc74 100644
--- a/glcdgraphics/common.c
+++ b/glcdgraphics/common.c
@@ -57,4 +57,61 @@ std::string trim(const std::string & s)
 	return s.substr(start, end - start + 1);
 }
 
+
+// character to return when erraneous utf-8 sequence  (for now: '_')
+#define UTF8_ERRCODE 0x005F
+void encodedCharAdjustCounter(const bool isutf8, const std::string & str, uint32_t & c, unsigned int & i)
+{
+    if (i >= str.length())
+        return;
+        
+    if ( isutf8 ) {
+        uint8_t c0,c1,c2,c3;
+        c = str[i];
+        c0 = str[i];
+        c1 = (i+1 < str.length()) ? str[i+1] : 0;
+        c2 = (i+2 < str.length()) ? str[i+2] : 0;
+        c3 = (i+3 < str.length()) ? str[i+3] : 0;
+        //c0 &=0xff; c1 &=0xff; c2 &=0xff; c3 &=0xff;
+
+        if ( (c0 & 0x80) == 0x00) {
+            // one byte: 0xxxxxxx
+            c = c0;
+        } else if ( (c0 & 0xE0) == 0xC0 ) {
+            // two byte utf8: 110yyyyy 10xxxxxx -> 00000yyy yyxxxxxx
+            if ( (c1 & 0xC0) == 0x80 ) {
+                c = ( (c0 & 0x1F) << 6 ) | ( (c1 & 0x3F) );
+            } else {
+                //syslog(LOG_INFO, "GraphLCD: illegal 2-byte UTF-8 sequence found: 0x%02x 0x%02x\n", c0, c1);
+                c = UTF8_ERRCODE;
+            }
+            i += 1;
+        } else if ( (c0 & 0xF0) == 0xE0 ) {
+            // three byte utf8: 1110zzzz 10yyyyyy 10xxxxxx -> zzzzyyyy yyxxxxxx
+            if ( ((c1 & 0xC0) == 0x80) && ((c2 & 0xC0) == 0x80) ) {
+                c = ( (c0 & 0x0F) << 12 ) | ( (c1 & 0x3F) << 6 ) | ( c2 & 0x3F );
+            } else {
+                //syslog(LOG_INFO, "GraphLCD: illegal 3-byte UTF-8 sequence found: 0x%02x 0x%02x 0x%02x\n", c0, c1, c2);
+                c = UTF8_ERRCODE;
+            }
+            i += 2;
+        } else if ( (c0 & 0xF8) == 0xF0 ) {
+            // four byte utf8: 11110www 10zzzzzz 10yyyyyy 10xxxxxx -> 000wwwzz zzzzyyyy yyxxxxxx
+            if ( ((c1 & 0xC0) == 0x80) && ((c2 & 0xC0) == 0x80) && ((c3 & 0xC0) == 0x80) ) {
+                c = ( (c0 & 0x07) << 18 ) | ( (c1 & 0x3F) << 12 ) | ( (c2 & 0x3F) << 6 ) | (c3 & 0x3F);
+            } else {
+                //syslog(LOG_INFO, "GraphLCD: illegal 4-byte UTF-8 sequence found: 0x%02x 0x%02x 0x%02x 0x%02x\n", c0, c1, c2, c3);
+                c = UTF8_ERRCODE;
+            }
+            i += 3;
+        } else {
+            // 1xxxxxxx is invalid!
+            //syslog(LOG_INFO, "GraphLCD: illegal 1-byte UTF-8 char found: 0x%02x\n", c0);
+            c = UTF8_ERRCODE;
+        }
+    } else {
+        c = str[i];
+    }
+}
+
 } // end of namespace