Introduction

This post is about how to install Allegro 5 library, Cmake, and VS Code on Linux machine, ubuntu Linux in particular, and to make and use VC Code as your IDE for the course.

Before moving forward, you are assumed to have good knowledge of Linux environment, are familiar with using tools on terminal.

Install GCC

If don’t have gcc installed on your Ubuntu system yet, install gcc now by running the following command on the terminal

    sudo apt install gcc
            

Install Allegro 5 library

2 - Install Allegro 5 binary Allegro 5 library binary for Ubuntu is distributed as a PPA package. To install a newest release of the library, do the following on a terminal:

1. First get system update with sudo apt update

       sudo apt update
               

2. then add the ppa package to the repository

       sudo add-apt-repository ppa:allegro/5.2    
   

3. now install the core library for Allegro game development

       sudo apt install liballegro5-dev 
           

4. You may also need to install the addons for image, True Font, audio, etc.

       sudo apt install liballegro-acodec5-dev liballegro-audio5-dev \
               liballegro-image5-dev liballegro-dialog5-dev liballegro-ttf5-dev \
               liballegro-physfs5-dev
   

once all these above are done, you will have the header files, the libraries installed on your system.

install cmake

CMake is needed for your game project development. it can be installed by running the following command on terminal:

    sudo apt install cmake

Install VS Code

VS Code is free open source code editor, and can be made to be IDE for different prorgramming languages. We will be using VS Code for game programming using Allegro in C/C++. It can be installed by going to code.visualstudio.com and download the .deb package onto your system, which will be a file with a name like code*.deb, under ~/Downloads, and than run the following command on your terminal

    sudo apt install ~/Downloads/code*.deb

Test your IDE for game programming using Allegro in C/C++

Now you are ready to test and write your first program using Allegro 5 game library.

1. First, make a folder within your home, say testallegro, and then launch Visual Studio Code, and then open the folder.
2. create a CPP file named main.cpp within the folder, and then copy the following code to the file and save:

   
   #include 
       #include 
           #include 
   
               int main()
               {
               al_init();
               al_install_keyboard();
   
               ALLEGRO_TIMER* timer = al_create_timer(1.0 / 30.0);
               ALLEGRO_EVENT_QUEUE* queue = al_create_event_queue();
               ALLEGRO_DISPLAY* disp = al_create_display(320, 200);
               ALLEGRO_FONT* font = al_create_builtin_font();
   
               al_register_event_source(queue, al_get_keyboard_event_source());
               al_register_event_source(queue, al_get_display_event_source(disp));
               al_register_event_source(queue, al_get_timer_event_source(timer));
   
               bool redraw = true;
               ALLEGRO_EVENT event;
   
               al_start_timer(timer);
               while(1)
               {
               al_wait_for_event(queue, &event);
   
               if(event.type == ALLEGRO_EVENT_TIMER)
               redraw = true;
               else 
               if((event.type == ALLEGRO_EVENT_KEY_DOWN) || 
                 (event.type == ALLEGRO_EVENT_DISPLAY_CLOSE))
               break;
   
               if(redraw && al_is_event_queue_empty(queue))
               {
               al_clear_to_color(al_map_rgb(0, 0, 0));
               al_draw_text(font, al_map_rgb(255, 255, 255), 0, 0, 0, "Hello world!");
               al_flip_display();
   
               redraw = false;
               }
               }
   
               al_destroy_font(font);
               al_destroy_display(disp);
               al_destroy_timer(timer);
               al_destroy_event_queue(queue);
   
               return 0;
               }
               

3. You now may be asked by VS Code to install C/C++ Runner extension to VS Code
4. You also need to CMake Tools by Microsoft, by clicking the extensions button on the left side of VS Code Window, and then search for CMake, then click CMake Tools link to install
5. now in the command palette of VS Code (from menu View or Ctrl + Shift + P ), type CMake and then choose CMake Quick Start, you will be asked to choose a C/C++ to use, and ask you to choose a name for the project, say testhello, and choose if you want to build an executable or library. Choose executable for our purpose.
   CMake will automatically generate a CMakeLists.txt within your project folder. Please remember that this is the master file CMake will need for a project, and the name must be exactly the same.
6. now you need to add the following to the CMakeLists.txt

       # link required allegro libraries
       TARGET_LINK_LIBRARIES(testhello allegro allegro_font allegro_ttf allegro_image
              allegro_primitives )
   

   
   Note the list of allegro libraries should include at least allegro, others can be added as needed.
   While making the above changes to the CMakeLists.txt file, you may also check the source file name within the add_executable( ) , and be sure it is the one you have created and want to use. If there are more than one source files, you need to include them all in the list, separated by space, not a colon as we usually see.
   As soon as it is saved, CMake will generate a (new) Makefile under build subfolder of the project folder.
7. Now open a terminal within VS Code, and then in the terminal, change working directory to build, and to build the project by simply run the command make on the terminal, it will generate an executable file, named testhello if it is not changed in the CMakeLists.txt, which is the first argument of the add_executable(…) statement
8. now you can run the program by running the following command on the terminal

   
       ./testhello
   
   

   
   If you see a window launched with Hello World! In it, then congratulations! You have succeeded. Congratulations!

References

1. 1 - The official getting started with Allegro 5, https://liballeg.org/a5docs/trunk/getting_started.html
2. 2 - Allegro Vivace, a good tutorial on introduction to programming with Allegro 5, https://github.com/liballeg/allegro_wiki/wiki/Allegro-Vivace
3. 3 – install Allegro 5 on Ubuntu Linux, https://github.com/liballeg/allegro_wiki/wiki/Install-Allegro-from-Ubuntu-PPAs
4. 4 - How to port Allegro project into Allegro 5, https://github.com/liballeg/allegro_wiki/wiki/Porting-Allegro-4-to-5
5. 5 - Amit's game programming Information http://www-cs-students.stanford.edu/~amitp/gameprog.html
6. 6 - Allegro Wiki, https://github.com/liballeg/allegro_wiki/wiki