Basic localization of the ImGUI texts.

src/slic3r/GUI/GUI_App.cpp

@@ -412,6 +412,7 @@ bool GUI_App::select_language(  wxArrayString & names,
 		//FIXME This is a temporary workaround, the correct solution is to switch to "C" locale during file import / export only.
 		wxSetlocale(LC_NUMERIC, "C");
         Preset::update_suffix_modified();
+		m_imgui->set_language(m_wxLocale->GetCanonicalName().ToUTF8().data());
         return true;
     }
     return false;
@@ -440,6 +441,7 @@ bool GUI_App::load_language()
 			//FIXME This is a temporary workaround, the correct solution is to switch to "C" locale during file import / export only.
             wxSetlocale(LC_NUMERIC, "C");
 			Preset::update_suffix_modified();
+			m_imgui->set_language(m_wxLocale->GetCanonicalName().ToUTF8().data());
             return true;
         }
     }

src/slic3r/GUI/ImGuiWrapper.cpp

@@ -25,7 +25,8 @@ namespace GUI {
 
 
 ImGuiWrapper::ImGuiWrapper()
-    : m_font_texture(0)
+    : m_glyph_ranges(nullptr)
+    , m_font_texture(0)
     , m_style_scaling(1.0)
     , m_mouse_buttons(0)
     , m_disabled(false)
@@ -49,6 +50,35 @@ bool ImGuiWrapper::init()
     return true;
 }
 
+void ImGuiWrapper::set_language(const std::string &language)
+{
+    const ImWchar *ranges = nullptr;
+    size_t idx = language.find('_');
+    std::string lang = (idx == std::string::npos) ? language : language.substr(0, idx);
+    static const ImWchar ranges_latin2[] =
+    {
+        0x0020, 0x00FF, // Basic Latin + Latin Supplement
+        0x0100, 0x017F, // Latin Extended-A
+        0,
+    };
+    if (lang == "cs" || lang == "pl") {
+        ranges = ranges_latin2;
+    } else if (lang == "ru" || lang == "uk") {
+        ranges = ImGui::GetIO().Fonts->GetGlyphRangesCyrillic();
+    } else if (lang == "jp") {
+        ranges = ImGui::GetIO().Fonts->GetGlyphRangesJapanese();
+    } else if (lang == "kr") {
+        ranges = ImGui::GetIO().Fonts->GetGlyphRangesKorean();
+    } else if (lang == "zh") {
+        ranges = ImGui::GetIO().Fonts->GetGlyphRangesChineseSimplifiedCommon();
+    }
+
+    if (ranges != m_glyph_ranges) {
+        m_glyph_ranges = ranges;
+        init_default_font(m_style_scaling);
+    }
+}
+
 void ImGuiWrapper::set_display_size(float w, float h)
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -210,7 +240,7 @@ void ImGuiWrapper::init_default_font(float scaling)
 
     ImGuiIO& io = ImGui::GetIO();
     io.Fonts->Clear();
-    ImFont* font = io.Fonts->AddFontFromFileTTF((Slic3r::resources_dir() + "/fonts/NotoSans-Regular.ttf").c_str(), font_size * scaling);
+    ImFont* font = io.Fonts->AddFontFromFileTTF((Slic3r::resources_dir() + "/fonts/NotoSans-Regular.ttf").c_str(), font_size * scaling, nullptr, m_glyph_ranges);
     if (font == nullptr) {
         font = io.Fonts->AddFontDefault();
         if (font == nullptr) {

src/slic3r/GUI/ImGuiWrapper.hpp

@@ -20,6 +20,7 @@ class ImGuiWrapper
     typedef std::map<std::string, ImFont*> FontsMap;
 
     FontsMap m_fonts;
+    const ImWchar *m_glyph_ranges;
     unsigned m_font_texture;
     float m_style_scaling;
     unsigned m_mouse_buttons;
@@ -32,6 +33,7 @@ public:
     bool init();
     void read_glsl_version();
 
+    void set_language(const std::string &language);
     void set_display_size(float w, float h);
     void set_style_scaling(float scaling);
     bool update_mouse_data(wxMouseEvent &evt);
@@ -59,6 +61,7 @@ public:
     bool want_keyboard() const;
     bool want_text_input() const;
     bool want_any_input() const;
+
 private:
     void init_default_font(float scaling);
     void create_device_objects();