Debug macros

As per the style guidelines, using <iostream> on the Max codebase is forbidden. It is for this reason that Max ships some debugging macros to print information to the terminal. They live at the Debug.hpp file.

Note: Debug macros only display the messages on debug builds.

There are six debugging macros included with Max:

• show(): Prints the message unconditionally in bright purple. This macro is used when you want to display some information ONLY during the development stage and plan to remove it later.

  // my_sum_function.cpp
  int sum(int lhs, int rhs) {
      show("The first number is ", lhs, "!");
      return lhs + rhs;
  }
  int result = sum(2, 4);
  

  

• trace(): Used for maximum verbosity messages. Information that you generally wouldn't want to see, but that is useful to have if you're trying to determine the exact state of the engine.

  // RenderManager/shaders/DefaultShaderInv.cpp
  void DefaultShaderInv::initObject(RenderObject *renderObject) {
      glBindVertexArray(renderObject->getVAO());
      trace("Bound VBO: ", renderObject->getVBO()[0]);
      glBindBuffer(GL_ARRAY_BUFFER, renderObject->getVBO()[0]);
      // ...
  }
  

  

• debug(): Used for medium verbosity messages. Information that lets you track the general state of Max, but not granular enough to tell exactly what it's currently doing.

  // InputManager/InputManager.cpp
  MXbool InputManager::isJoistickConnected() {
      MXbool connected = glfwJoystickPresent(GLFW_JOYSTICK_1) == GLFW_TRUE;
      if (connected) debug("Joystick connected.");
      return connected;
  }
  

  

• info(): Used for information you always want to have.

  // EngineLogic/MaxBuilder.cpp
  Max MaxBuilder::build() {
      // ...
      Input = new InputManager();
      Camera *camera = new Camera(_screen_width, _screen_height);
      Render = new RenderManager(_screen_width, _screen_height, camera);
      Max max(_camera, _scene, _window);
  
      info("New Max instance created.");
      return max
  }
  

  

• warn(): Used to indicate something went wrong, but that it is not a critical issue and the engine can recover from it.

  // RenderManager/ModelLoader.cpp
  ModelObject *ModelLoader::create_model_object(std::string name, const MXchar *model_src) {
      Assimp::Importer importer;
      const aiScene *scene = importer.ReadFile(
          model_src, aiProcess_Triangulate | aiProcess_FlipUVs | aiProcess_PreTransformVertices | aiProcess_GenNormals);
  
      if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) {
          warn("File ", model_src, " does not contain a model!");
          // ...
      }
      // ...
  }
  

  

• error(): Used for critical errors the engine cannot recover from, and most likely result in a crash.

  // EngineLogic/MaxBuilder.cpp
  Max MaxBuilder::build() {
      // ...
  
      if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
          error("GLAD failed to initialize");
          throw BuildExeption(Cause::Faliure, Item::Internal);
      }
  
      // ...
  }
  

  

As you will have noticed, their structure is: DEBUG_LEVEL [file_name:function_name:line_number] user message.

Besides show(), debug macro messages will not be displayed by default, even on debug builds. They have to be enabled through the LOG_LEVEL environment variable.

The levels correspond to the macro names, and are ordered from least to most verbosity in the following list: ERROR < WARN < INFO < DEBUG < TRACE. Enabling a debug level automatically enables all the previous ones on the list.

LOG_LEVEL=INFO ./my_max_game Will show ERROR, WARN and DEBUG messages.