Game Library for C++
What is a game library?
A game library is a group of programs that offer basic game development features like graphics, music, input, and physics. The development process can be speed up, and the creation of complicated games can be made simpler by using game libraries.
How can a game library be helpful?
Utilizing a game library has a lot of advantages. The top few are listed below:
- Speed up development: You can avoid writing a lot of the fundamental functionality required for game creation by using game libraries. You can save a tonne of time and work by doing this.
- Make it simpler to construct complex games: A variety of strong features offered by game libraries can be leveraged to produce complex games. It is a fantastic technique to raise the calibre of your games.
- Reduce the possibility of errors: Game libraries are frequently thoroughly tested and dependable, so you can be sure that they will function as intended. It might assist you in lowering the possibility of mistakes in your gaming.
- Make it simpler to share code: Since game libraries may be exchanged with other developers, working on game projects together may become simpler.
Popular C++ game libraries:
There are numerous well-liked C++ gaming libraries, but a few of the more well-liked ones are as follows:
- SDL: SDL is a cross-platform library that gives games the essential features they need, including graphics, audio, and input.
- Another cross-platform library, SFML, offers more sophisticated features than SDL, including networking, audio, and 2D and 3D graphics.
- AAA games can be made with the help of the sophisticated game engine Unreal Engine. It is written in the visual scripting language Blueprints and C++.
- Unity: You can make games of various sizes using Unity, another well-liked game engine. Although it is coded in C#, C++ scripting is supported.
These are only a few of the several well-liked C++ game libraries. Your unique demands and requirements will determine which library is appropriate for you.
How to configure the C++ game development environment:
1.Install the selected game library together with any prerequisites.
Installing the game library you intend to utilize is the first step. For instance, you can install SDL from the SDL website at https://www.libsdl.org/ if you want to utilize it. You must additionally install the game library's dependencies after you have set up the game library. For instance, since SDL requires the OpenGL graphics package, you must also install OpenGL.
2.Set up your IDE to support game creation.
Once the game's library and its necessary components have been installed, you must set up your IDE for creating games. Setting up the debugger, linker, and compiler will be required. Based on the IDE you are using, there may be different procedures to configure your IDE.
The following general steps will show you how to set up a few well-liked IDEs for C++ game development:
- You must configure Visual Studio's linker and compiler to use the SDL libraries in accordance with the C++17 standard. The debugger can be set to stop on errors as well.
- Code::Blocks: You must include the SDL libraries in the project's code. You must include locations and library paths in Code::Blocks. The debugger can be set to stop on errors as well.
- CLion for JetBrains: The built-in SDL support in CLion can be used to set up your project for game creation.
3. Make a fresh undertaking.
You can start a new project once your IDE has been configured. Based on the IDE you are using, there may be differences in the particular processes for establishing a new project.
By choosing File > New > Project in Visual Studio, you can start a new project by choosing the Blank Project template. You must set the project's target framework to C++17 and its language to C++ in the project's properties.
By choosing File > New > Project in Code::Blocks and the Console Application template, you can start a new project. You must add the SDL libraries to the project's include directories and library paths in the project's settings.
4. Write your code:
You can begin writing your code once you have started a new project. To develop your game, use the game library you had installed at the first stage.
5. Run and compile your code:
You may compile and run your code after you've finished writing it. You can use a compiler that you set up in the second step to compile your code. You can utilize the debugger you've set up in the following step to run your code.
Using the game library, you can write the following "Hello, World!" program:
#include <stdio.h>
#include <SDL2/SDL.h>
int main() {
// Declare variables
int screen_width = 800;
int screen_height = 600;
SDL_Window *window;
SDL_Event event;
// Initialize SDL
if (SDL_Init(SDL_INIT_EVERYTHING) != 0) {
printf("SDL initialization failed: %s\n", SDL_GetError());
return 1;
}
// Create a window
window = SDL_CreateWindow("Hello SDL World", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, screen_width, screen_height, SDL_WINDOW_ALLOW_HIGHDPI);
if (NULL == window) {
printf("Could not create window: %s\n", SDL_GetError());
SDL_Quit();
return 1;
}
// Main loop
while (1) {
// Poll for events
if (SDL_PollEvent(&event)) {
// Check for quit event
if (event.type == SDL_QUIT) {
break;
}
}
}
// Destroy the window
SDL_DestroyWindow(window);
// Quit SDL
SDL_Quit();
return 0;
}
Output:
![Game Library for C++](https://static.tutorialandexample.com/cpp/game-library-for-cpp1.png)
Basic elements of a game loop:
- Receiving player input, including as keystrokes, clicks on the mouse, and joystick motions, is known as input handling. After that, the state of the game is managed using this input.
- Changing the internal state of the game based on input received is known as updating the game state. It could entail shifting things around, altering the states of creatures, or updating the physics of the game.
- Drawing the game's scene onto the screen is known as rendering. It entails taking the internal state of the game and turning it into displayable graphical primitives.
Typically, a while loop is used to implement the game loop, which continues to run till the game is finished. The input handling, game state update, and scene rendering are all done in the same loop. A straightforward C++ instance of a game loop is as follows:
while (true) {
// Handle input.
// Update game state.
// Render scene.
}
According to the game being produced, each of these processes will be implemented differently. The game loop continues to adhere to the same broad format, though.
Rendering Sprites, Shapes, and Text in C++ with OpenGL:
Sprites: Two-dimensional images that can be displayed to the screen are known as sprites. In video games, sprites are frequently used to represent objects, characters, and other components. The vertices of the sprite must be stored in a vertex buffer object (VBO), and the indices that link the vertices must be stored in the index buffer object (IBO) before you can draw the sprite. A texture that holds the sprite's image must also be made. After making these objects, rendering the sprite is as simple as combining the VBO and IBO before binding the texture.
Shapes: A form is a geometric entity that can be shown on the screen in two or three dimensions. In video games, floors, walls, and other features are frequently represented using shapes. A vertex buffer object, which holds the form's vertices, and an index buffer object, which saves the indices used to connect the vertices, must be created in order to draw a shape. You must also indicate the kind of form, such as a rectangle, square, or circle, that you want to render. By connecting the VBO and IBO and then invoking the relevant rendering function after creating these objects, you may render the shape.
Text: OpenGL can also be used to render text on the screen. Create a texture containing the text before binding it to a shader to produce text. After that, the text can be rendered to the screen using the shader.
Textures:
After being loaded into memory, textures are connected to a shader. A texture is added to the item when a shader is employed for rendering it, giving it the impression that it has a surface.
The glTexImage2D() method in OpenGL can be used to load a texture. The height and width of the texture, the texture's format, and the data itself are all inputs for this function. After the texture is loaded, you can use the glBindTexture() function to attach it to a shader.
Using the glDrawElements() function, you can show a texture on the screen. The kind of primitives to draw, how many vertices there are, and the index buffer object are all inputs for this function.
Methods for handling user input for interacting with games in C++:
Keyboard entry: You can ask the user for keyboard input using the std::cin object. For instance, the code shown below will retrieve a particular character from the keyboard:
char ch;
std::cin >> ch;
Mouse input: The user's mouse input can be obtained using the SDL or GLFW libraries. For instance, the mouse location can be obtained using the code below:
int x, y;
SDL_GetMouseState(&x, &y);
Controller input: The user's controller input can also be obtained using the SDL or GLFW libraries. For instance, the left joystick's condition can be determined by the code below:
float x, y;
SDL_JoystickGetAxis(joystick, 0, &x, &y);
You can use the user input to regulate the game state once you've gotten it. For instance, you can advance the player character ahead by pressing the W key. A projectile can be fired if the button on the left is clicked.
The unique game you are building will determine how you should handle user input. However, most games should adhere to the broad guidelines provided above.
Ways to manage game logic and state in C++:
Game objects: The fundamental components of a game are called game objects. They could stand in for anything, including characters, adversaries, weapons, and power-ups. Typically, game objects contain attributes like velocity, position, and rotation. Additionally, they exhibit behaviours like movement, collisions, and interactions with other in-game objects.
Collision detection: It is crucial for video games that feature actual physical interactions like projectile and character collisions. The optimal collision detection algorithm to utilize will rely on the particular game being developed because there are numerous alternative techniques available.
Physics: The study of movement and forces is known as physics. It can be applied to make virtual game items behave like they would in reality. For instance, physics can be utilized to determine a projectile's trajectory or the pulling force of a hit. The ideal physics engine to employ will depend on the particular game being produced because there are numerous different physics engines out there.
Game state: The game's current state is known as the game state. It contains details about the locations of game objects, the health of the individuals, and the environment's condition. As the game develops, the status of the game is continually changing.
Depending on the exact game you are designing, you will handle game logic and data differently. However, most games should adhere to the broad guidelines provided above.
For handling game logic and state, take into account the following extra factors:
Data structures: Your game's performance will be significantly impacted by the data structures you choose to store game objects along with additional data. When selecting data structures, be sure that they are effective for the activities you will be performing.
Algorithms: Your game's performance will be greatly affected by the algorithms you employ for collision detection, science, and other activities. It is best to select algorithms that are effective for the particular task at hand.
Abstraction: It is a method that can be utilized to streamline the game logic and state management code. It entails organising related ideas into groups and making it easier to access them. Code that is abstracted can be easier to read and maintain.
Modularization is a method that can be used to divide the code for controlling game logic and state into more manageable, independent modules. This may make the code easier to handle and troubleshootable.
The particular game you are building will determine the optimal method for handling game logic and state. However, the factors mentioned above ought to make it easier for you to select the ideal strategy for your game.
Audio Libraries for C++ Games:
FMOD: Many games use FMOD, a cross-platform audio library. It offers several different features, such as music, sound effects, and 3D audio.
Many operating systems support the open-source audio library known as OpenAL. For games that must be portable, it is a good option.
BASS: The BASS audio library is a freeware program that runs on macOS, Windows, and Linux. Numerous features are supported, such as sound effects, songs, and streaming audio.
CLAM: CLAM is a multi-platform audio library made specifically for real-time applications like games. It enables a wide range of functions, such as spatial audio, music, and sound effects.
Depending on the precise features you require and the platforms that you wish to support, you can choose the appropriate audio collection for your game. Although, the libraries mentioned above are all excellent options and can be utilized to provide excellent sound for your games.
Here are some further factors to take into account while selecting an audio library:
Features: The audio library should include the features you require, including music, sound effects, 3D audio, and streaming audio.
Platforms: Target systems should be able to use the audio library, including Linux, macOS, Windows, and mobile devices.
Performance: The audio library ought to run smoothly and with little latency.
A user-friendly audio library that integrates with the game engine is essential.
These are only a few of the core ideas in C++ game creation. You will also need to master a variety of other ideas and methods if you want to succeed as a game producer.