Update localization:

* 2D.pm, 3DPreview.pm, PreviewData.cpp are marked by L()
* use translating function in 3DScene.cpp

xs/src/libslic3r/GCode/PreviewData.cpp

@@ -1,6 +1,7 @@
 #include "Analyzer.hpp"
 #include "PreviewData.hpp"
 #include <float.h>
+#include "slic3r/GUI/GUI.hpp"
 
 namespace Slic3r {
 
@@ -132,21 +133,21 @@ const GCodePreviewData::Color GCodePreviewData::Extrusion::Default_Extrusion_Rol
 // todo: merge with Slic3r::ExtrusionRole2String() from GCode.cpp
 const std::string GCodePreviewData::Extrusion::Default_Extrusion_Role_Names[Num_Extrusion_Roles]
 {
-    "None",
-    "Perimeter",
-    "External perimeter",
-    "Overhang perimeter",
-    "Internal infill",
-    "Solid infill",
-    "Top solid infill",
-    "Bridge infill",
-    "Gap fill",
-    "Skirt",
-    "Support material",
-    "Support material interface",
-    "Wipe tower",
-    "Custom",
-    "Mixed"
+    L("None"),
+    L("Perimeter"),
+    L("External perimeter"),
+    L("Overhang perimeter"),
+    L("Internal infill"),
+    L("Solid infill"),
+    L("Top solid infill"),
+    L("Bridge infill"),
+    L("Gap fill"),
+    L("Skirt"),
+    L("Support material"),
+    L("Support material interface"),
+    L("Wipe tower"),
+    L("Custom"),
+    L("Mixed")
 };
 
 const GCodePreviewData::Extrusion::EViewType GCodePreviewData::Extrusion::Default_View_Type = GCodePreviewData::Extrusion::FeatureType;
@@ -325,15 +326,15 @@ std::string GCodePreviewData::get_legend_title() const
     switch (extrusion.view_type)
     {
     case Extrusion::FeatureType:
-        return "Feature type";
+        return L("Feature type");
     case Extrusion::Height:
-        return "Height (mm)";
+        return L("Height (mm)");
     case Extrusion::Width:
-        return "Width (mm)";
+        return L("Width (mm)");
     case Extrusion::Feedrate:
-        return "Speed (mm/s)";
+        return L("Speed (mm/s)");
     case Extrusion::Tool:
-        return "Tool";
+        return L("Tool");
     }
 
     return "";

xs/src/slic3r/GUI/3DScene.cpp

@@ -27,6 +27,8 @@
 #include <wx/image.h>
 #include <wx/settings.h>
 
+#include "GUI.hpp"
+
 namespace Slic3r {
 
 void GLIndexedVertexArray::load_mesh_flat_shading(const TriangleMesh &mesh)
@@ -1144,7 +1146,7 @@ bool _3DScene::LegendTexture::generate(const GCodePreviewData& preview_data, con
     m_data.clear();
 
     // collects items to render
-    const std::string& title = preview_data.get_legend_title();
+    auto title = GUI::L_str(preview_data.get_legend_title());
     const GCodePreviewData::LegendItemsList& items = preview_data.get_legend_items(tool_colors);
 
     unsigned int items_count = (unsigned int)items.size();
@@ -1166,7 +1168,7 @@ bool _3DScene::LegendTexture::generate(const GCodePreviewData& preview_data, con
     unsigned int max_text_height = 0;
     for (const GCodePreviewData::LegendItem& item : items)
     {
-        memDC.GetTextExtent(item.text, &w, &h);
+        memDC.GetTextExtent(GUI::L_str(item.text), &w, &h);
         max_text_width = std::max(max_text_width, (unsigned int)w);
         max_text_height = std::max(max_text_height, (unsigned int)h);
     }
@@ -1243,7 +1245,7 @@ bool _3DScene::LegendTexture::generate(const GCodePreviewData& preview_data, con
         memDC.DrawRectangle(wxRect(icon_x_inner, icon_y + 1, px_inner_square, px_inner_square));
 
         // draw text
-        memDC.DrawText(item.text, text_x, icon_y + text_y_offset);
+		memDC.DrawText(GUI::L_str(item.text), text_x, icon_y + text_y_offset);
 
         // update y
         icon_y += icon_y_step;

xs/src/slic3r/GUI/GUI.cpp

@@ -531,7 +531,7 @@ void create_combochecklist(wxComboCtrl* comboCtrl, std::string text, std::string
 
         for (const std::string& item : items_str)
         {
-            popup->Append(item);
+            popup->Append(from_u8(item));
         }
 
         for (unsigned int i = 0; i < popup->GetCount(); ++i)