[Metal] Add Metal support to Minimal Scene

- Set ogre2 render engine as default and ensure the Qt surface format supports OpenGL 4.1
- Default ogre render engine to version to ogre2 in CMakeLists.txt, scene3d.config and Scene3D.
- Set default QSurfaceFormat to OpenGL 4.1 in applications
- cherry-pick 066d276
- Experimental support for Metal in Scene3D and MinimalScene plugins (OpenGL is disabled)
- Modify examples/standalone/window to use Metal backend in the Qt scene graph and force render loop to be single threaded
- Modify ign.cc commandlets to use Metal backend in the Qt scene graph and force render loop to be single threaded
- Use CFBridgingRetain / CFBridgingRelease to manage access to Metal texture objects.
- Force render engine to initialise on the main thread.
- Fix build after interface changes
- Fix build after changes in gazebosim/gz-rendering#477
- Reverse changes to isolate issues in transform control
- Add cross-platform support to MinimalScene TextureNode
- Introduce abstract delegate class for the TextureNode
- Add implementations for OpenGL and Metal
- Add cross-platform support to MinimalScene RenderThread
- Introduce abstract delegate class for the RenderThread
- Add implementations for OpenGL and Metal
- Update CMakeLists.txt for cross-platform
- Only include objective-c and Apple frameworks for macOS
- Add render interface for a camera texture
- Change name of render interface files
- Refactor file names to use `Rhi` suffix
- Refactor names of render interface classes
- Replace Delegate with Rhi (render hardware interface - from Qt)
- Add render hardware interface for the ignition renderer
- Update MinimalScene to use a render hardware interface to retrieve the camera texture
- Convert MinimalScene back to c++
- All Metal specific code moved out of MinimalScene to render interface classes
- Rename MinimalScene and compile as c++
- Allow render system to be switched between Metal and OpenGL
  - Add method SetRenderSystem
  - Update classes in MinimalScene to allow the render system to be set in the plugin XML
  - Move all scene graph backend config to Application
- Set textureDirty flag true on initialisation
- Fix an issue where the initial texture is not sized correctly on initialisation leading to aliasing artefacts
- Fix after rebasing onto ign-gui6

[QML] update function call syntax in Connections blocks
- Change syntax to address warning: QML Connections: Implicitly defined onFoo properties in Connections are deprecated
- Qt 5.15, see: https://doc.qt.io/qt-5/qml-qtqml-connections.html
- Add missing properties for tooltopDelay
- cherry-pick ac51e07

Signed-off-by: Rhys Mainwaring <[email protected]>

CMakeLists.txt

@@ -39,12 +39,12 @@ ign_find_package(TINYXML2 REQUIRED PRIVATE PRETTY tinyxml2)
 
 #--------------------------------------
 # Find ignition-math
-ign_find_package(ignition-math6 REQUIRED VERSION 6.5)
+ign_find_package(ignition-math6 REQUIRED VERSION 6.9)
 set(IGN_MATH_VER ${ignition-math6_VERSION_MAJOR})
 
 #--------------------------------------
 # Find ignition-common
-ign_find_package(ignition-common4 REQUIRED COMPONENTS profiler VERSION 4.1)
+ign_find_package(ignition-common4 REQUIRED COMPONENTS profiler VERSION 4.4)
 set(IGN_COMMON_VER ${ignition-common4_VERSION_MAJOR})
 
 #--------------------------------------
@@ -59,8 +59,8 @@ set(IGN_TRANSPORT_VER ${ignition-transport11_VERSION_MAJOR})
 
 #--------------------------------------
 # Find ignition-rendering
-ign_find_package(ignition-rendering6 REQUIRED COMPONENTS ogre)
-set(IGN_RENDERING_VER ${ignition-rendering6_VERSION_MAJOR})
+ign_find_package(ignition-rendering7 REQUIRED COMPONENTS ogre2)
+set(IGN_RENDERING_VER ${ignition-rendering7_VERSION_MAJOR})
 
 #--------------------------------------
 # Find ignition-msgs

examples/standalone/window/window.cc

@@ -16,26 +16,66 @@
 */
 
 #include <iostream>
+#include <sstream>
 
 #ifndef Q_MOC_RUN
   #include <ignition/gui/qt.h>
   #include <ignition/gui/Application.hh>
   #include <ignition/gui/MainWindow.hh>
 #endif
 
+#include <tinyxml2.h>
+
 //////////////////////////////////////////////////
 int main(int _argc, char **_argv)
 {
   std::cout << "Hello, GUI!" << std::endl;
 
+  // must be called before the widget or its parent window gets shown
+//  QSurfaceFormat format(QSurfaceFormat::DeprecatedFunctions);
+//  format.setDepthBufferSize(24);
+//  format.setStencilBufferSize(8);
+//  format.setVersion(4, 1);
+//  format.setProfile(QSurfaceFormat::CoreProfile);
+//  format.setRenderableType(QSurfaceFormat::OpenGL);
+//  QSurfaceFormat::setDefaultFormat(format);
+
+  // TODO: OpenGL/Metal
+  // Use single-threaded scene graph rendering
+  qputenv("QSG_RENDER_LOOP", "basic");
+
+  // TODO: OpenGL/Metal
+  // Use Metal backend
+  QQuickWindow::setSceneGraphBackend(QSGRendererInterface::MetalRhi);
+
   // Increase verboosity so we see all messages
   ignition::common::Console::SetVerbosity(4);
 
   // Create app
   ignition::gui::Application app(_argc, _argv);
 
+  // Create plugin XML
+  std::string _filename("");
+  std::ostringstream ss;
+  ss << "<plugin filename=\"MinimalScene\">"
+    << "  <ignition-gui>"
+    << "    <title>View 1</title>"
+    << "    <property type=\"string\" key=\"state\">docked</property>"
+    << "  </ignition-gui>"
+    << "  <engine>ogre2</engine>"
+    << "  <scene>scene</scene>"
+    << "  <skybox></skybox>"
+    << "  <ambient_light>1 1 1</ambient_light>"
+    << "  <background_color>0.8 0.8 0.8</background_color>"
+    << "  <camera_pose>-6 0 6 0 0.5 0</camera_pose>"
+    << "</plugin>\n";
+
+  tinyxml2::XMLDocument pluginDoc;
+  pluginDoc.Parse(ss.str().c_str());
+  tinyxml2::XMLElement *pluginElem{pluginDoc.FirstChildElement("plugin")};
+
   // Load plugins / config
-  if (!app.LoadPlugin("Publisher"))
+  if (!app.LoadPlugin("MinimalScene", pluginElem))
   {
     return 1;
   }

include/ignition/gui/qml/PluginMenu.qml

@@ -48,7 +48,10 @@ Popup {
       id: searchSortBar
       color: searchColor
       height: 50
-      width: parent.width
+      // incorrect: https://stackoverflow.com/questions/63767669/parent-is-null-in-listview-delegate-after-upgrade-to-qt-5-15
+      // width: parent.width
+      width: pluginMenuListView.width
+
       RowLayout {
         id: rowLayout
         anchors.fill: parent

src/Application.cc

@@ -86,6 +86,35 @@ Application::Application(int &_argc, char **_argv, const WindowType _type)
 {
   igndbg << "Initializing application." << std::endl;
 
+  // TODO(srmainwaring): OpenGL/Metal
+  std::string renderSystem = "metal";
+  if (renderSystem.compare("opengl") == 0)
+  {
+    // Must be called before the widget or its parent window gets shown
+    QSurfaceFormat format(QSurfaceFormat::DeprecatedFunctions);
+    format.setDepthBufferSize(24);
+    format.setStencilBufferSize(8);
+    format.setVersion(4, 1);
+    format.setProfile(QSurfaceFormat::CoreProfile);
+    format.setRenderableType(QSurfaceFormat::OpenGL);
+    QSurfaceFormat::setDefaultFormat(format);
+  }
+#if __APPLE__
+  else if (renderSystem.compare("metal") == 0)
+  {
+    igndbg << "Qt using Metal rendering interface" << std::endl;
+    qputenv("QSG_RENDER_LOOP", "basic");
+    QQuickWindow::setSceneGraphBackend(QSGRendererInterface::MetalRhi);
+  }
+#endif
+  else
+  {
+    ignerr << "Invalid render system: " << renderSystem << std::endl;
+  }
+
+  // Increase verbosity so we see all messages
+  ignition::common::Console::SetVerbosity(4);
+
   // Configure console
   common::Console::SetPrefix("[GUI] ");
 

src/plugins/grid_3d/Grid3D_TEST.cc

@@ -45,7 +45,7 @@ TEST(Grid3DTest, WithoutScene)
   EXPECT_TRUE(createMainWindow());
 
   // Check there is no scene
-  auto engine = rendering::engine("ogre");
+  auto engine = rendering::engine("ogre2");
   ASSERT_NE(nullptr, engine);
 
   EXPECT_EQ(0u, engine->SceneCount());
@@ -65,7 +65,7 @@ TEST(Grid3DTest, CRUD)
   // Load plugin
   const char *pluginStr =
     "<plugin filename=\"Grid3D\">"
-      "<engine>ogre</engine>"
+      "<engine>ogre2</engine>"
       "<scene>scene</scene>"
       "<insert>"
         "<cell_count>5</cell_count>"

src/plugins/minimal_scene/CMakeLists.txt

@@ -1,9 +1,40 @@
+set(SOURCES
+  MinimalScene.cc
+  MinimalSceneRhi.cc
+  MinimalSceneRhiOpenGL.cc
+)
+
+set(PROJECT_LINK_LIBS "")
+
+# Objective-C sources for macOS
+if (APPLE)
+  set(SOURCES
+    ${SOURCES}
+    MinimalSceneRhiMetal.mm
+  )
+
+  set(PROJECT_LINK_LIBS
+    "-framework AppKit"
+    "-framework Metal"
+  )
+endif()
+
 ign_gui_add_plugin(MinimalScene
   SOURCES
-    MinimalScene.cc
+    ${SOURCES}
   QT_HEADERS
     MinimalScene.hh
   PUBLIC_LINK_LIBS
    ignition-rendering${IGN_RENDERING_VER}::ignition-rendering${IGN_RENDERING_VER}
+   ${PROJECT_LINK_LIBS}
 )
 
+# Enable ARC on selected source files
+if (APPLE)
+  set_source_files_properties(
+      MinimalSceneRhiMetal.mm
+      PROPERTIES
+      COMPILE_FLAGS
+          "-fobjc-arc"
+  )
+endif()