[plugins] add plugins loading method

src/CMakeLists.txt

@@ -149,6 +149,7 @@ endif()
 find_package(Boost REQUIRED COMPONENTS program_options)
 
 add_executable(mc_mujoco main.cpp)
+target_compile_definitions(mc_mujoco PUBLIC MUJOCO_BIN_DIR="${MUJOCO_BIN_DIR}")
 target_link_libraries(mc_mujoco PRIVATE mc_mujoco_lib Boost::program_options
                                         Boost::disable_autolinking)
 

src/main.cpp

@@ -12,6 +12,30 @@ namespace po = boost::program_options;
 
 bool render_state = true;
 
+#define MUJOCO_PLUGIN_DIR "mujoco_plugin"
+
+void scanPluginLibraries()
+{
+// define platform-specific strings
+#if defined(_WIN32) || defined(__CYGWIN__)
+  const std::string sep = "\\";
+#else
+  const std::string sep = "/";
+#endif
+
+  const std::string plugin_dir = MUJOCO_BIN_DIR + sep + MUJOCO_PLUGIN_DIR;
+  mj_loadAllPluginLibraries(
+      plugin_dir.c_str(),
+      +[](const char * filename, int first, int count)
+      {
+        std::printf("Plugins registered by library '%s':\n", filename);
+        for(int i = first; i < first + count; ++i)
+        {
+          std::printf("    %s\n", mjp_getPluginAtSlot(i)->name);
+        }
+      });
+}
+
 void simulate(mc_mujoco::MjSim & mj_sim)
 {
   bool done = false;
@@ -68,6 +92,9 @@ int main(int argc, char * argv[])
       config.visualize_collisions = vm["with-collisions"].as<bool>();
     }
   }
+
+  scanPluginLibraries();
+
   mc_mujoco::MjSim mj_sim(config);
 
   std::thread simThread(simulate, std::ref(mj_sim));