This article will discuss how to use the DragonRuby Egg (CLI) application. We will try out how to create a new game project and add some modules to it. One of the modules is a 15 puzzle game that will be independent of the code architecture of the already created game project.
DragonRuby Egg (CLI) is a prototype and is primarily designed for Linux distribution. If you are using another operating system, it is possible that the application will not work properly.
In order to use DragonRuby Egg (CLI), you need to install it. (Just use the gem command from the ruby ecosystem.)
gem install dragonruby-eggAfter installing the gem, we will use the dre command, which runs DragonRuby Egg (CLI) application. To test if the application works, we'll write down what version we have:
dre -vIt should run the program from the message that it was not found the root path for DragonRuby has been found. This dre application communicates with DragonRuby application and therefore the dre application automatically tries to find where DragonRuby is installed. This may take a while. If it finds you path, it will tell you which path it found and then list the version of dre application. It is recommended that the application version be 1.0.4 and above.
Here is a sample of the dre application listing:
filip@travelmate:~$ dre -v
9:11:03 AM [dre] ROOT-PATH | The root path has not been set and so the analysis of the root path is performed.
9:11:28 AM [dre] SET | root_path: /home/filip/.local/opt/dragonruby-linux-amd64
9:11:28 AM [dre] VERSION | 1.0.4If the dre application couldn't automatically find the path to DragonRuby, you need to set it manually. Please take a look using this command for more information:
dre -h
It's time to create a new game project using the command. For example, name the project dre_tutorial and create it on the desktop. Then we'll start the project and check it out, to see if it works.
Here is the command to create a new project:
dre new dre_tutorial ~/DesktopA new project will be created and we can start it using the dre command. Just add the path to the project here and run the command. This will start the game project.
Here is the command to start the new project:
dre ~/Desktop/dre_tutorialIf everything goes right, you will see the DragonRuby welcome window.
In order to run the 15 puzzle game, we install it as a module in the project. This game has one dependency on the module that favors object-oriented architecture. During installation, we'll test what happens if we don't have the another module for the code dependency and then we install it.
As a first step, we set up the primary path to the project:
cd ~/Desktop/dre_tutorialThe next step is to look at the DragonRuby Egg website and find out the name of the modules we need to install.
(pic. 1) DragonRuby Egg website with module names highlighted in red.
We need these modules:
- fifteen-puzzle-dr
- dr-core-rb
As the website suggests, just write a command to install the name module, which we've already looked up. The first thing we do is install the fifteen-puzzle-dr module.
Here is the command to install the first module with the relevant project path:
dre install fifteen-puzzle-dr .The dre application will ask us if we really want to install this module. We confirm with y and then the github repository is cloned. At the end, the application will automatically change the paths to be relevant for the newly created game project.
Here's a sample of the dre application dump:
filip@travelmate:~/Desktop/dre_tutorial$ dre install fifteen-puzzle-dr .
Install this 'filipvrba.fifteen-puzzle-dr' module? (y/N): y
Cloning into './modules/fifteen-puzzle-dr'...
remote: Enumerating objects: 233, done.
remote: Counting objects: 100% (233/233), done.
remote: Compressing objects: 100% (146/146), done.
remote: Total 233 (delta 74), reused 199 (delta 43), pack-reused 0
Receiving objects: 100% (233/233), 207.36 KiB | 419.00 KiB/s, done.
Resolving deltas: 100% (74/74), done.
10:11:48 AM [dre] INSTALL | The 'fifteen-puzzle-dr' module has been installed in this './modules/fifteen-puzzle-dr' folder.
10:11:48 AM [dre] INSTALL | All paths for this 'fifteen-puzzle-dr' module have been changed.To run this installed fifteen-puzzle-dr module in our game project, we import it into the app/main.rb file and then initialize it. This should get the 15 puzzle game up and running in our game project.
Here is the overall code for the main.rb file:
# ./app/main.rb
require 'modules/fifteen-puzzle-dr/app/init.rb' # <= The code has been added here.
def tick args
args.outputs.labels << [640, 540, 'Hello World!', 5, 1]
args.outputs.labels << [640, 500, 'Docs located at ./docs/docs.html and 100+ samples located under ./samples', 5, 1]
args.outputs.labels << [640, 460, 'Join the Discord server! https://discord.dragonruby.org', 5, 1]
args.outputs.sprites << { x: 576,
y: 280,
w: 128,
h: 101,
path: 'dragonruby.png',
angle: args.state.tick_count }
args.outputs.labels << { x: 640,
y: 60,
text: './mygame/app/main.rb',
size_enum: 5,
alignment_enum: 1 }
FifteenPuzzleDR.init args # <= The code has been added here.
endIt should give us an error when we start the game project. It tells us that it is expecting a module named dr-core-rb. This module, as I mentioned earlier, is a dependency for the fifteen-puzzle-dr module and needs to be reinstalled.
Here I will give the command to start the game project:
dre .In the window or in the terminal we get an error message, here is an example of the message:
...
INFO: modules/dr-core-rb/lib/core-1.0.1/core.rb does not exist. (RuntimeError)
- 000000 [Game] Game state and exception will be written to logs/exceptions/game_state_-1.txt and logs/exceptions/current.txt.
- 000000 [Game] * EXCEPTION: modules/dr-core-rb/lib/core-1.0.1/core.rb does not exist.
** Backtrace:
*** modules/fifteen-puzzle-dr/app/init.rb:2 (-1)To fix this bug, we will install a second module in the game project. This will fix the functionality of the code for the fifteen-puzzle-dr module.
Here is the command to install the second module:
dre install dr-core-rb .When we start the dre_tutorial project, we will be rendered 15 puzzle game. For the demonstration we left the welcome code from DragonRuby and can be noticed, the overlapping of the rendered objects. That's okay.
(pic. 2) Running a game project with rendered objects overlapping each other.
And that's the end of the tutorial for DragonRuby Egg (CLI). We showed how to use the dre tool to create a new project and install modules to get a working game of 15 puzzles up and running. As you can see, we wrote very little code in the game project. We just implemented the 2 lines of code needed to get the 15 puzzles moving.