some cleanup and refactoring, nothing functional

src/utils.cpp

@@ -48,3 +48,82 @@ uint16_t HSVtoRGB565(float h, float s, float v) {
 
   return ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3);
 }
+
+String convertToUTF8(const wchar_t* input) {
+  String output;
+  while (*input) {
+    uint32_t unicode = *input;
+    if (unicode < 0x80) output += (char)unicode;
+    else if (unicode < 0x800) {
+      output += (char)(0xC0 | (unicode >> 6));
+      output += (char)(0x80 | (unicode & 0x3F));
+    } else if (unicode < 0x10000) {
+      output += (char)(0xE0 | (unicode >> 12));
+      output += (char)(0x80 | ((unicode >> 6) & 0x3F));
+      output += (char)(0x80 | (unicode & 0x3F));
+    } else {
+      output += (char)(0xF0 | (unicode >> 18));
+      output += (char)(0x80 | ((unicode >> 12) & 0x3F));
+      output += (char)(0x80 | ((unicode >> 6) & 0x3F));
+      output += (char)(0x80 | (unicode & 0x3F));
+    }
+    input++;
+  }
+  return output;
+}
+
+String trimTrailingSpaces(String str) {
+  int end = str.length() - 1;
+  while (end >= 0 && isspace(str[end])) end--;
+  return str.substring(0, end + 1);
+}
+
+String ucs2ToUtf8(const char* ucs2Input) {
+  String utf8Output;
+
+  size_t length = 0;
+  while (ucs2Input[length] != '\0' || ucs2Input[length + 1] != '\0') length += 2;
+
+  for (size_t i = 0; i < length; i += 2) {
+    uint16_t ucs2Char = ((uint8_t)ucs2Input[i] << 8) | (uint8_t)ucs2Input[i + 1];
+
+    if (ucs2Char <= 0x7F) utf8Output += (char)ucs2Char;
+    else if (ucs2Char <= 0x7FF) {
+      utf8Output += (char)(0xC0 | (ucs2Char >> 6));
+      utf8Output += (char)(0x80 | (ucs2Char & 0x3F));
+    } else {
+      utf8Output += (char)(0xE0 | (ucs2Char >> 12));
+      utf8Output += (char)(0x80 | ((ucs2Char >> 6) & 0x3F));
+      utf8Output += (char)(0x80 | (ucs2Char & 0x3F));
+    }
+  }
+  return utf8Output;
+}
+
+String extractUTF8Substring(const String & utf8String, size_t start, size_t length, bool underscore) {
+  String substring;
+  size_t utf8Length = utf8String.length();
+  size_t utf8Index = 0;
+  size_t charIndex = 0;
+
+  while (utf8Index < utf8Length && charIndex < start + length) {
+    uint8_t currentByte = utf8String.charAt(utf8Index);
+    uint8_t numBytes = 0;
+
+    if (currentByte < 0x80) numBytes = 1;
+    else if ((currentByte >> 5) == 0x6) numBytes = 2;
+    else if ((currentByte >> 4) == 0xE) numBytes = 3;
+    else if ((currentByte >> 3) == 0x1E) numBytes = 4;
+
+    if (charIndex >= start) substring += utf8String.substring(utf8Index, utf8Index + numBytes);
+
+    utf8Index += numBytes;
+    charIndex++;
+  }
+
+  if (underscore) {
+    while (substring.length() < length) substring += '_';
+  }
+
+  return substring;
+}