[experimental] Wayland build on Linux

[tibordp]

This is the minimum changes I needed to get PrusaSlicer working on native Wayland. It's probably broken in subtle and not-so-subtle ways, but the basic functionality works on my machine and it's finally not blurry anymore with fractional scaling.

Included changes:

• upgrade wxWidgets to 3.2.5
• use EGL glCanvas
• switch GLEW to EGL mode to prevent crash on start (Crash on start - SIGSEGV in ImFont::CalcTextSizeA #9774)
• some minor code fixups in GUI (I imagine stemming from new wxWidgets)

[lukasmatena]

Thanks. We will definitely have a look and test it. It would be nice if you could update your PR so the commit does not do the needless whitespace changes. For now, this is the diff without them:

diff --git a/deps/+GLEW/GLEW.cmake b/deps/+GLEW/GLEW.cmake
index c2db9117b6..280caec26b 100644
--- a/deps/+GLEW/GLEW.cmake
+++ b/deps/+GLEW/GLEW.cmake
@@ -5,4 +5,5 @@ add_cmake_project(
   SOURCE_SUBDIR build/cmake
   CMAKE_ARGS
     -DBUILD_UTILS=OFF
+    -DGLEW_EGL=ON
 )
diff --git a/deps/+wxWidgets/wxWidgets.cmake b/deps/+wxWidgets/wxWidgets.cmake
index 77c12ee72f..9aa11938d9 100644
--- a/deps/+wxWidgets/wxWidgets.cmake
+++ b/deps/+wxWidgets/wxWidgets.cmake
@@ -28,8 +28,8 @@ else ()
 endif ()
 
 add_cmake_project(wxWidgets
-    URL https://github.com/prusa3d/wxWidgets/archive/323a465e577e03f330e2e6a4c78e564d125340cb.zip
-    URL_HASH SHA256=B538E4AD3CC93117932F4DED70C476D6650F9C70A9D4055A08F3693864C47465
+    URL https://github.com/wxWidgets/wxWidgets/releases/download/v3.2.5/wxWidgets-3.2.5.tar.bz2
+    URL_HASH SHA256=0AD86A3AD3E2E519B6A705248FC9226E3A09BBF069C6C692A02ACF7C2D1C6B51
     CMAKE_ARGS
         "-DCMAKE_DEBUG_POSTFIX:STRING="
         -DwxBUILD_PRECOMP=ON
@@ -50,7 +50,7 @@ add_cmake_project(wxWidgets
         -DwxUSE_EXPAT=sys
         -DwxUSE_LIBSDL=OFF
         -DwxUSE_XTEST=OFF
-        -DwxUSE_GLCANVAS_EGL=OFF
+        -DwxUSE_GLCANVAS_EGL=ON
         -DwxUSE_WEBREQUEST=OFF
         ${_wx_webview}
         ${_wx_secretstore}
diff --git a/src/PrusaSlicer.cpp b/src/PrusaSlicer.cpp
index ccabc07485..a0676c15fb 100644
--- a/src/PrusaSlicer.cpp
+++ b/src/PrusaSlicer.cpp
@@ -85,13 +85,6 @@ int CLI::run(int argc, char **argv)
     // Save the thread ID of the main thread.
     save_main_thread_id();
 
-#ifdef __WXGTK__
-    // On Linux, wxGTK has no support for Wayland, and the app crashes on
-    // startup if gtk3 is used. This env var has to be set explicitly to
-    // instruct the window manager to fall back to X server mode.
-    ::setenv("GDK_BACKEND", "x11", /* replace */ true);
-#endif
-
 	// Switch boost::filesystem to utf8.
     try {
         boost::nowide::nowide_filesystem();
diff --git a/src/slic3r/GUI/PhysicalPrinterDialog.cpp b/src/slic3r/GUI/PhysicalPrinterDialog.cpp
index 11ca1249c9..b4577f7492 100644
--- a/src/slic3r/GUI/PhysicalPrinterDialog.cpp
+++ b/src/slic3r/GUI/PhysicalPrinterDialog.cpp
@@ -606,7 +606,8 @@ void PhysicalPrinterDialog::build_printhost_settings(ConfigOptionsGroup* m_optgr
     // Always fill in the "printhost_port" combo box from the config and select it.
     {
         Choice* choice = dynamic_cast<Choice*>(m_optgroup->get_field("printhost_port"));
-        choice->set_values({ m_config->opt_string("printhost_port") });
+        std::vector<std::string> vals { m_config->opt_string("printhost_port") };
+        choice->set_values(vals);
         choice->set_selection();
     }
 
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index bbaf4c5d73..d66331efc7 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -4048,7 +4048,8 @@ void Plater::load_project(const wxString& filename)
 
     p->reset();
 
-    if (! load_files({ into_path(filename) }).empty()) {
+    std::vector<boost::filesystem::path> input_files { into_path(filename) };
+    if (! load_files(input_files).empty()) {
         // At least one file was loaded.
         p->set_project_filename(filename);
         // Save the names of active presets and project specific config into ProjectDirtyStateManager.