Moved Odaki's implemetation of searching for end of utf8 sequence to separate function.

+ Fix of 0xC0 in trailer bytes 
followup on fff862a5ae4b013f9a4ca20161b514f7fb0574e8

4 files changed, 72 insertions, 101 deletions

diff --git a/src/libslic3r/Utils.hpp b/src/libslic3r/Utils.hpp
index cfb4cfa92..d9419495e 100644
--- a/src/libslic3r/Utils.hpp
+++ b/src/libslic3r/Utils.hpp
@@ -74,6 +74,10 @@ extern local_encoded_string encode_path(const char *src);
 extern std::string decode_path(const char *src);
 extern std::string normalize_utf8_nfc(const char *src);
 
+// Returns next utf8 sequence length. =number of bytes in string, that creates together one utf-8 character. 
+// Starting at pos. ASCII characters returns 1. Works also if pos is in the middle of the sequence.
+extern size_t get_utf8_sequence_length(const std::string& text, size_t pos = 0);
+
 // Safely rename a file even if the target exists.
 // On Windows, the file explorer (or anti-virus or whatever else) often locks the file
 // for a short while, so the file may not be movable. Retry while we see recoverable errors.
diff --git a/src/libslic3r/utils.cpp b/src/libslic3r/utils.cpp
index 7e4b281fd..c74e57e99 100644
--- a/src/libslic3r/utils.cpp
+++ b/src/libslic3r/utils.cpp
@@ -863,6 +863,71 @@ std::string normalize_utf8_nfc(const char *src)
     return boost::locale::normalize(src, boost::locale::norm_nfc, locale_utf8);
 }
 
+size_t get_utf8_sequence_length(const std::string& text, size_t pos)
+{
+	assert(pos < text.size());
+	size_t length = 0;
+	unsigned char c = text[pos];
+	if (c < 0x80) { // 0x00-0x7F
+		// is ASCII letter
+		length++;
+	}
+	// Bytes 0x80 to 0xBD are trailer bytes in a multibyte sequence.
+	// pos is in the middle of a utf-8 sequence. Add the utf-8 trailer bytes.
+	else if (c < 0xC0) { // 0x80-0xBF
+		length++;
+		while (pos + length < text.size()) {
+			c = text[pos + length];
+			if (c < 0x80 || c >= 0xC0) {
+				break; // prevent overrun
+			}
+			length++; // add a utf-8 trailer byte
+		}
+	}
+	// Bytes 0xC0 to 0xFD are header bytes in a multibyte sequence.
+	// The number of one bits above the topmost zero bit indicates the number of bytes (including this one) in the whole sequence.
+	else if (c < 0xE0) { // 0xC0-0xDF
+	 // add a utf-8 sequence (2 bytes)
+		if (pos + 2 > text.size()) {
+			return text.size() - pos; // prevent overrun
+		}
+		length += 2;
+	}
+	else if (c < 0xF0) { // 0xE0-0xEF
+	 // add a utf-8 sequence (3 bytes)
+		if (pos + 3 > text.size()) {
+			return text.size() - pos; // prevent overrun
+		}
+		length += 3;
+	}
+	else if (c < 0xF8) { // 0xF0-0xF7
+	 // add a utf-8 sequence (4 bytes)
+		if (pos + 4 > text.size()) {
+			return text.size() - pos; // prevent overrun
+		}
+		length += 4;
+	}
+	else if (c < 0xFC) { // 0xF8-0xFB
+	 // add a utf-8 sequence (5 bytes)
+		if (pos + 5 > text.size()) {
+			return text.size() - pos; // prevent overrun
+		}
+		length += 5;
+	}
+	else if (c < 0xFE) { // 0xFC-0xFD
+	 // add a utf-8 sequence (6 bytes)
+		if (pos + 6 > text.size()) {
+			return text.size() - pos; // prevent overrun
+		}
+		length += 6;
+	}
+	else { // 0xFE-0xFF
+	 // not a utf-8 sequence
+		length++;
+	}
+	return length;
+}
+
 namespace PerlUtils {
     // Get a file name including the extension.
     std::string path_to_filename(const char *src)       { return boost::filesystem::path(src).filename().string(); }
diff --git a/src/slic3r/GUI/HintNotification.cpp b/src/slic3r/GUI/HintNotification.cpp
index 91c9d71c8..291ce8f40 100644
--- a/src/slic3r/GUI/HintNotification.cpp
+++ b/src/slic3r/GUI/HintNotification.cpp
@@ -615,56 +615,7 @@ void NotificationManager::HintNotification::count_lines()
 					float width_of_a = ImGui::CalcTextSize("a").x;
 					int letter_count = (int)((m_window_width - m_window_width_offset) / width_of_a);
 					while (last_end + letter_count < text.size() && ImGui::CalcTextSize(text.substr(last_end, letter_count).c_str()).x < m_window_width - m_window_width_offset) {
-						size_t text_size = text.size();
-						size_t current_position = last_end + letter_count;
-						unsigned char c = text[current_position];
-						if (c < 0x80) { // 0x00-0x7F
-							// add ASCII letter
-							letter_count++;
-						} else if (c < 0xC0) { // 0x80-0xBF
-							// it is in the middle of a utf-8 sequence. add the utf-8 trailer bytes.
-							letter_count++;
-							while (last_end + letter_count < text.size()) {
-								c = text[last_end + letter_count];
-								if (c < 0x80 || c > 0xC0) {
-									break; // prevent overrun
-								}
-								letter_count++; // add a utf-8 trailer byte
-							}
-						} else if (c < 0xE0) { // 0xC0-0xDF
-							// add a utf-8 sequence (2 bytes)
-							if (current_position + 2 > text_size) {
-								break; // prevent overrun
-							}
-							letter_count += 2;
-						} else if (c < 0xF0) { // 0xE0-0xEF
-							// add a utf-8 sequence (3 bytes)
-							if (current_position + 3 > text_size) {
-								break; // prevent overrun
-							}
-							letter_count += 3;
-						} else if (c < 0xF8) { // 0xF0-0xF7
-							// add a utf-8 sequence (4 bytes)
-							if (current_position + 4 > text_size) {
-								break; // prevent overrun
-							}
-							letter_count += 4;
-						} else if (c < 0xFC) { // 0xF8-0xFB
-							// add a utf-8 sequence (5 bytes)
-							if (current_position + 5 > text_size) {
-								break; // prevent overrun
-							}
-							letter_count += 5;
-						} else if (c < 0xFE) { // 0xFC-0xFD
-							// add a utf-8 sequence (6 bytes)
-							if (current_position + 6 > text_size) {
-								break; // prevent overrun
-							}
-							letter_count += 6;
-						} else { // 0xFE-0xFF
-							// not a utf-8 sequence
-							letter_count++;
-						}
+						letter_count += get_utf8_sequence_length(text, last_end + letter_count);
 					}
 					m_endlines.push_back(last_end + letter_count);
 					last_end += letter_count;
@@ -734,56 +685,7 @@ void NotificationManager::HintNotification::count_lines()
 						float width_of_a = ImGui::CalcTextSize("a").x;
 						int letter_count = (int)((m_window_width - m_window_width_offset - size_of_last_line) / width_of_a);
 						while (last_end + letter_count < text.size() && ImGui::CalcTextSize(text.substr(last_end, letter_count).c_str()).x < m_window_width - m_window_width_offset - size_of_last_line) {
-							size_t text_size = text.size();
-							size_t current_position = last_end + letter_count;
-							unsigned char c = text[current_position];
-							if (c < 0x80) { // 0x00-0x7F
-								// add ASCII letter
-								letter_count++;
-							} else if (c < 0xC0) { // 0x80-0xBF
-								// it is in the middle of a utf-8 sequence. add the utf-8 trailer bytes.
-								letter_count++;
-								while (last_end + letter_count < text.size()) {
-									c = text[last_end + letter_count];
-									if (c < 0x80 || c > 0xC0) {
-										break; // prevent overrun
-									}
-									letter_count++; // add a utf-8 trailer byte
-								}
-							} else if (c < 0xE0) { // 0xC0-0xDF
-								// add a utf-8 sequence (2 bytes)
-								if (current_position + 2 > text_size) {
-									break; // prevent overrun
-								}
-								letter_count += 2;
-							} else if (c < 0xF0) { // 0xE0-0xEF
-								// add a utf-8 sequence (3 bytes)
-								if (current_position + 3 > text_size) {
-									break; // prevent overrun
-								}
-								letter_count += 3;
-							} else if (c < 0xF8) { // 0xF0-0xF7
-								// add a utf-8 sequence (4 bytes)
-								if (current_position + 4 > text_size) {
-									break; // prevent overrun
-								}
-								letter_count += 4;
-							} else if (c < 0xFC) { // 0xF8-0xFB
-								// add a utf-8 sequence (5 bytes)
-								if (current_position + 5 > text_size) {
-									break; // prevent overrun
-								}
-								letter_count += 5;
-							} else if (c < 0xFE) { // 0xFC-0xFD
-								// add a utf-8 sequence (6 bytes)
-								if (current_position + 6 > text_size) {
-									break; // prevent overrun
-								}
-								letter_count += 6;
-							} else { // 0xFE-0xFF
-								// not a utf-8 sequence
-								letter_count++;
-							}
+							letter_count += get_utf8_sequence_length(text, last_end + letter_count);
 						}
 						m_endlines2.push_back(last_end + letter_count);
 						last_end += letter_count;
diff --git a/src/slic3r/GUI/NotificationManager.cpp b/src/slic3r/GUI/NotificationManager.cpp
index 66c22cb9b..aab0dbbab 100644
--- a/src/slic3r/GUI/NotificationManager.cpp
+++ b/src/slic3r/GUI/NotificationManager.cpp
@@ -301,7 +301,7 @@ void NotificationManager::PopNotification::count_lines()
 					float width_of_a = ImGui::CalcTextSize("a").x;
 					int letter_count = (int)((m_window_width - m_window_width_offset) / width_of_a);
 					while (last_end + letter_count < text.size() && ImGui::CalcTextSize(text.substr(last_end, letter_count).c_str()).x < m_window_width - m_window_width_offset) {
-						letter_count++;
+						letter_count += get_utf8_sequence_length(text, last_end + letter_count);
 					}
 					m_endlines.push_back(last_end + letter_count);
 					last_end += letter_count;