C++ OpenGL 3D Game Tutorial 1: Making the Window with Win32 API

Summary

In this first episode of the OpenGL 3D game tutorial series, we guide you through creating a 3D game window in C++ using the Win32 API and OpenGL. We start with setting up the development environment in Visual Studio, followed by creating the Window and Game classes. The Window class is responsible for managing the creation and destruction of the game window, while the Game class handles the main game loop and event processing. By the end of this episode, viewers will have a functional window ready for rendering 3D content in future tutorials.

Takeaways

• 😀 The tutorial series focuses on building a 3D game from scratch using C++ and OpenGL.
• 😀 Visual Studio 2019 Community is recommended for the IDE, though other C++ IDEs may also work.
• 😀 The tutorial starts with the creation of the window for rendering 3D objects in the game.
• 😀 The game’s design involves two main classes: Window (for window management) and Game (for handling the game loop and execution).
• 😀 Knowledge of C++ is recommended for following the tutorial, but not strictly necessary for beginners.
• 😀 The project is organized into separate folders for the game code and OpenGL engine code, with source and include directories.
• 😀 The `Window` class is built using the Win32 API and is responsible for creating and managing the window.
• 😀 The `Game` class contains the game loop and handles events, such as window closure, by processing messages.
• 😀 The game loop runs until the `isRunning` flag is set to false, triggered by a window closure event.
• 😀 Smart pointers, such as `std::unique_ptr`, are recommended for memory management to avoid leaks and simplify cleanup.
• 😀 Error handling during window creation is done using the `assert()` function to ensure the registration of the window class succeeds.

Q & A

What is the main objective of this tutorial series?

The main objective of this tutorial series is to teach how to build a 3D game from scratch using C++ and OpenGL, starting with creating a window to render 3D objects.

What are the recommended development tools for this tutorial?

The tutorial recommends using Visual Studio 2019 Community Edition as the C++ IDE, though other C++ IDEs can be used. The target graphics API is OpenGL, and the initial target platform is Windows, followed by macOS and Linux later.

Why is Visual Studio strongly recommended for this tutorial?

Visual Studio is strongly recommended because of its comprehensive support for C++ development, including features like code completion, debugging tools, and easy integration with libraries like OpenGL.

What are the two main classes discussed in the design phase?

The two main classes discussed are the `Window` class, which handles the creation and management of the window, and the `Game` class, which manages the game loop and other game functionalities.

How is the project structure organized in this tutorial?

The project is organized with a `game` folder containing game-related code and an `engine` folder containing the OpenGL 3D engine code. The engine folder is further divided into `include` (for header files) and `source` (for C++ implementation files).

What is the purpose of the `WndClassX` structure in the window creation process?

The `WndClassX` structure defines the properties of a window class, such as the window's style and behavior. It is used to register a window class with the operating system before creating the window.

Why is the `CreateWindowEx` function used and what does it do?

The `CreateWindowEx` function is used to create a new window by specifying properties like window size, style, title, and position. It returns a handle to the created window, which is essential for interacting with the window.

What is the role of the `Game` class in the game loop?

The `Game` class contains a `run` method that implements the game loop. This loop continuously checks for window events and processes them until a condition is met, such as the user closing the window.

What is the purpose of using `std::unique_ptr` for memory management in the tutorial?

The `std::unique_ptr` is used for automatic memory management. It ensures that the `Window` object is properly destroyed when the `Game` object is destructed, preventing memory leaks.

How does the window procedure handle closing the window?

The window procedure uses a `WM_CLOSE` message to detect when the user tries to close the window. Upon receiving this message, it posts a quit message to the message queue, which causes the game loop to terminate.