Option to list rendering backends

application/F3DOptionsTools.cxx

@@ -64,12 +64,13 @@ static inline const std::array<CLIGroup, 8> CLIOptions = {{
     { { "output", "", "Render to file", "<png file>", "" },
       { "no-background", "", "No background when render to file", "<bool>", "1" },
       { "help", "h", "Print help", "", "" }, { "version", "", "Print version details", "", "" },
-      { "readers-list", "", "Print the list of readers", "", "" },
-      { "bindings-list", "", "Print the list of interaction bindings and exits, ignored with `--no-render`, only considers the first file group.", "", "" },
+      { "list-readers", "", "Print the list of readers", "", "" },
+      { "list-bindings", "", "Print the list of interaction bindings and exits, ignored with `--no-render`, only considers the first file group.", "", "" },
       { "config", "", "Specify the configuration file to use. absolute/relative path or filename/filestem to search in configuration file locations", "<filePath/filename/fileStem>", "" },
       { "dry-run", "", "Do not read the configuration file", "<bool>", "1" },
       { "no-render", "", "Do not read the configuration file", "<bool>", "1" },
       { "rendering-backend", "", "Backend to use when rendering (auto|glx|wgl|egl|osmesa)", "<string>", "" },
+      { "list-rendering-backends", "", "Print the list of rendering backends available on this system", "", "" },
       { "max-size", "", "Maximum size in Mib of a file to load, leave empty for unlimited", "<size in Mib>", "" },
 #if F3D_MODULE_DMON
       { "watch", "", "Watch current file and automatically reload it whenever it is modified on disk", "<bool>", "1" },
@@ -175,7 +176,7 @@ static inline const std::array<CLIGroup, 8> CLIOptions = {{
  * True boolean options need to be filtered out in ParseCLIOptions
  * This is the easiest, compile time way to do it
  */
-constexpr std::array<std::string_view, 4> CLIBooleans = {"version", "help", "readers-list", "scan-plugins"};
+constexpr std::array CLIBooleans = {"version", "help", "list-readers", "scan-plugins", "list-rendering-backends"};
 
 //----------------------------------------------------------------------------
 /**
@@ -269,6 +270,19 @@ void PrintVersion()
   f3d::log::setUseColoring(true);
 }
 
+//----------------------------------------------------------------------------
+void PrintRenderingBackendList()
+{
+  auto backends = f3d::engine::getRenderingBackendList();
+
+  f3d::log::setUseColoring(false);
+  f3d::log::info("Rendering backends:");
+  for (const auto& [name, available] : backends)
+  {
+    f3d::log::info(name + ": " + (available ? "available" : "unavailable"));
+  }
+}
+
 //----------------------------------------------------------------------------
 void PrintReadersList()
 {
@@ -484,14 +498,19 @@ F3DOptionsTools::OptionsDict F3DOptionsTools::ParseCLIOptions(
       ::PrintVersion();
       throw F3DExNoProcess("version requested");
     }
+    if (result.count("list-rendering-backends") > 0)
+    {
+      ::PrintRenderingBackendList();
+      throw F3DExNoProcess("rendering backend list requested");
+    }
     if (result.count("scan-plugins") > 0)
     {
       ::PrintPluginsScan();
       throw F3DExNoProcess("scan plugins requested");
     }
-    if (result.count("readers-list") > 0)
+    if (result.count("list-readers") > 0)
     {
-      // `--readers-list` needs plugin to be loaded to be useful
+      // `--list-readers` needs plugin to be loaded to be useful
       // Load them manually
       std::vector<std::string> plugins;
       if (result.count("load-plugins") > 0)

application/F3DOptionsTools.h

@@ -27,7 +27,7 @@ using OptionsEntries = std::vector<OptionsEntry>;
 static inline const OptionsDict DefaultAppOptions = {
   { "input", "" },
   { "output", "" },
-  { "bindings-list", "false" },
+  { "list-bindings", "false" },
   { "no-background", "false" },
   { "config", "" },
   { "dry-run", "false" },

application/F3DStarter.cxx

@@ -543,7 +543,7 @@ class F3DStarter::F3DInternals
   {
     // Update typed app options from app options
     this->AppOptions.Output = f3d::options::parse<std::string>(appOptions.at("output"));
-    this->AppOptions.BindingsList = f3d::options::parse<bool>(appOptions.at("bindings-list"));
+    this->AppOptions.BindingsList = f3d::options::parse<bool>(appOptions.at("list-bindings"));
     this->AppOptions.NoBackground = f3d::options::parse<bool>(appOptions.at("no-background"));
     this->AppOptions.NoRender = f3d::options::parse<bool>(appOptions.at("no-render"));
     this->AppOptions.RenderingBackend =

application/testing/CMakeLists.txt

@@ -1030,9 +1030,9 @@ f3d_test(NAME TestConfigFileNoOptions DATA cow.vtp CONFIG ${F3D_SOURCE_DIR}/test
 # Test update interaction verbose
 f3d_test(NAME TestConfigFileBindingsVerbose DATA dragon.vtu ARGS --verbose CONFIG ${F3D_SOURCE_DIR}/testing/configs/bindings.json REGEXP "'Shift.O' : '`toggle model.point_sprites.enable` '" NO_BASELINE)
 
-# Test bindings-list display with config file
-f3d_test(NAME TestConfigFileBindingsList ARGS --bindings-list CONFIG ${F3D_SOURCE_DIR}/testing/configs/bindings.json REGEXP "Ctrl.Shift.O `toggle ui.filename`" NO_BASELINE)
-f3d_test(NAME TestConfigFileBindingsListData DATA dragon.vtu ARGS --bindings-list CONFIG ${F3D_SOURCE_DIR}/testing/configs/bindings.json REGEXP "Any.3        `roll_camera 90`" NO_BASELINE)
+# Test list-bindings display with config file
+f3d_test(NAME TestConfigFileBindingsList ARGS --list-bindings CONFIG ${F3D_SOURCE_DIR}/testing/configs/bindings.json REGEXP "Ctrl.Shift.O `toggle ui.filename`" NO_BASELINE)
+f3d_test(NAME TestConfigFileBindingsListData DATA dragon.vtu ARGS --list-bindings CONFIG ${F3D_SOURCE_DIR}/testing/configs/bindings.json REGEXP "Any.3        `roll_camera 90`" NO_BASELINE)
 
 # Test invalid value in config file
 f3d_test(NAME TestConfigFileInvalidValue DATA cow.vtp CONFIG ${F3D_SOURCE_DIR}/testing/configs/invalid_value.json REGEXP "must be a string, a boolean or a number" NO_BASELINE)
@@ -1056,19 +1056,19 @@ f3d_test(NAME TestHelpPositional ARGS --help REGEXP "file1 file2 \.\.\.")
 # Test version display
 f3d_test(NAME TestVersion ARGS --version REGEXP "Version:")
 
-# Test readers-list display
-f3d_test(NAME TestReadersList ARGS --readers-list REGEXP_FAIL "No registered reader found")
+# Test list-readers display
+f3d_test(NAME TestReadersList ARGS --list-readers REGEXP_FAIL "No registered reader found")
 
 # Test invalid component string coverage
 f3d_test(NAME TestInteractionInvalidComponent INTERACTION UI DATA cow.vtp ARGS --coloring-component=1 NO_BASELINE) #H
 
-# Test multi plugin readers-lists
+# Test multi plugin list-readers
 if(F3D_PLUGIN_BUILD_ALEMBIC AND F3D_PLUGIN_BUILD_ASSIMP)
-  f3d_test(NAME TestReadersListMultiplePlugins ARGS --readers-list --load-plugins=assimp,alembic NO_BASELINE REGEXP_FAIL "Plugin failed to load")
+  f3d_test(NAME TestReadersListMultiplePlugins ARGS --list-readers --load-plugins=assimp,alembic NO_BASELINE REGEXP_FAIL "Plugin failed to load")
 endif()
 
-# Test bindings-list display
-f3d_test(NAME TestBindingsList ARGS --bindings-list REGEXP "Any.Question Print scene descr to terminal")
+# Test list-bindings display
+f3d_test(NAME TestBindingsList ARGS --list-bindings REGEXP "Any.Question Print scene descr to terminal")
 
 # Test rendering backends
 # For some reason the sanitizer detects leaks because of EGL and OSMesa
@@ -1144,6 +1144,25 @@ f3d_test(NAME TestHelpPrecedenceWithUnknownOption ARGS --help --unknown REGEXP "
 # Test that --version is displayed even when there is an unknown option
 f3d_test(NAME TestVersionPrecedenceWithUnknownOption ARGS --version --unknown REGEXP "Version:" NO_BASELINE)
 
+# Test rendering backend list
+if(WIN32)
+  f3d_test(NAME TestRenderingBackenListWGL ARGS --list-rendering-backends NO_RENDER NO_BASELINE REGEXP "wgl: available")
+elseif(APPLE)
+  f3d_test(NAME TestRenderingBackenListCOCOA ARGS --list-rendering-backends NO_RENDER NO_BASELINE REGEXP "cocoa: available")
+endif()
+
+if(F3D_TESTING_ENABLE_GLX_TESTS AND VTK_VERSION VERSION_GREATER_EQUAL 9.3.20240914)
+  f3d_test(NAME TestRenderingBackenListGLX ARGS --list-rendering-backends NO_RENDER NO_BASELINE REGEXP "glx: available")
+endif()
+
+if(F3D_TESTING_ENABLE_EGL_TESTS AND VTK_VERSION VERSION_GREATER_EQUAL 9.3.20240914)
+  f3d_test(NAME TestRenderingBackenListEGL ARGS --list-rendering-backends NO_RENDER NO_BASELINE REGEXP "egl: available")
+endif()
+
+if(F3D_TESTING_ENABLE_OSMESA_TESTS)
+  f3d_test(NAME TestRenderingBackenListOSMesa ARGS --list-rendering-backends NO_RENDER NO_BASELINE REGEXP "osmesa: available")
+endif()
+
 # Test scan plugins
 if(NOT F3D_MACOS_BUNDLE)
   f3d_test(NAME TestScanPluginsCheckNative ARGS --scan-plugins NO_RENDER NO_BASELINE REGEXP " - native")

doc/user/CONFIGURATION_FILE.md

@@ -65,7 +65,7 @@ The third block specifies raytracing usage for .gltf and .glb files.
 The last block specifies that volume rendering should be used with .mhd files.
 
 The following options <b> cannot </b> be set via config file:
-`help`, `version`, `readers-list`, `config`, `dry-run` and `input`.
+`help`, `version`, `list-readers`, `config`, `dry-run` and `input`.
 
 The following options <b>are only taken on the first load</b>:
 `no-render`, `output`, `position`, `resolution`, `frame-rate` and all testing options.
@@ -115,7 +115,7 @@ interaction on the `Any+3` bind and even define a bindings that have multiple co
 on the `Ctrl+O` bind.
 
 Please note this configuration feature is only available through config file and not through the command line.
-However, it is possible to check your current binding configuration by using the `--bindings-list` CLI options.
+However, it is possible to check your current binding configuration by using the `--list-bindings` CLI options.
 
 ### Bind
 

doc/user/OPTIONS.md

@@ -13,7 +13,7 @@ Options|Default|Description
 \-\-no-background||Use with \-\-output to output a png file with a transparent background.
 -h, \-\-help||Print *help* and exit. Ignore `--verbose`.
 \-\-version||Show *version* information and exit. Ignore `--verbose`.
-\-\-readers-list||List available *readers* and exit. Ignore `--verbose`.
+\-\-list-readers||List available *readers* and exit. Ignore `--verbose`.
 \-\-config=\<config file path/name/stem\>|config|Specify the [configuration file](CONFIGURATION_FILE.md) to use. Supports absolute/relative path but also filename/filestem to search for in standard configuration file locations.
 \-\-dry-run||Do not read any configuration file and consider only the command line options.
 \-\-no-render||Do not render anything and quit just after loading the first file, use with \-\-verbose to recover information about a file.

library/public/engine.h

@@ -198,6 +198,12 @@ class F3D_EXPORT engine
    */
   interactor& getInteractor();
 
+  /**
+   * List rendering backends supported by libf3d.
+   * All backends have an associated boolean flag indicating if it can be used.
+   */
+  static std::map<std::string, bool> getRenderingBackendList();
+
   /**
    * Load a plugin.
    * Supports full path, relative path, and plugin name.

library/src/engine.cxx

@@ -25,6 +25,19 @@
 class engine::internals
 {
 public:
+  template<typename F>
+  static bool BackendAvailable(F&& func)
+  {
+    try
+    {
+      return func() != nullptr;
+    }
+    catch (const context::loading_exception&)
+    {
+      return false;
+    }
+  }
+
   std::unique_ptr<options> Options;
   std::unique_ptr<detail::window_impl> Window;
   std::unique_ptr<detail::scene_impl> Scene;
@@ -212,6 +225,20 @@
   return *this->Internals->Interactor;
 }
 
+//----------------------------------------------------------------------------
+std::map<std::string, bool> engine::getRenderingBackendList()
+{
+  std::map<std::string, bool> backends;
+
+  backends["glx"] = engine::internals::BackendAvailable(context::glx);
+  backends["wgl"] = engine::internals::BackendAvailable(context::wgl);
+  backends["cocoa"] = engine::internals::BackendAvailable(context::cocoa);
+  backends["egl"] = engine::internals::BackendAvailable(context::egl);
+  backends["osmesa"] = engine::internals::BackendAvailable(context::osmesa);
+
+  return backends;
+}
+
 //----------------------------------------------------------------------------
 void engine::loadPlugin(const std::string& pathOrName, const std::vector<std::string>& searchPaths)
 {

python/F3DPythonBindings.cxx

@@ -404,7 +404,8 @@ PYBIND11_MODULE(pyf3d, module)
       "autoload_plugins", &f3d::engine::autoloadPlugins, "Automatically load internal plugins")
     .def_static("get_plugins_list", &f3d::engine::getPluginsList)
     .def_static("get_lib_info", &f3d::engine::getLibInfo, py::return_value_policy::reference)
-    .def_static("get_readers_info", &f3d::engine::getReadersInfo);
+    .def_static("get_readers_info", &f3d::engine::getReadersInfo)
+    .def_static("get_rendering_backend_list", &f3d::engine::getRenderingBackendList);
 
   // libInformation
   py::class_<f3d::engine::libInformation>(module, "LibInformation")

python/testing/test_engine.py

@@ -62,3 +62,9 @@ def test_get_readers_info():
         assert isinstance(reader.plugin_name, str) and reader.plugin_name
         assert isinstance(reader.has_scene_reader, bool)
         assert isinstance(reader.has_geometry_reader, bool)
+
+
+def test_get_rendering_backend_list():
+    backends = f3d.Engine.get_rendering_backend_list()
+
+    assert isinstance(backends, dict) and len(backends) == 5