l-system

Assignment Informatica Werktuigen (academic year 2021-2022).

Installation

Clone this repository to your local computer.

git clone https://github.com/crearth/l-system.git

Configure a python virtual environment with venv.

python3 -m venv l-venv

Use the virtual environment.

source l-venv/bin/activate

Install the packages via pip.

pip install -r requirements.txt

Install the tkinter package.

sudo apt-get install python3-tk

Use

Run the main.py file.

python3 main.py

It will ask you which configuration file it should use and how many iterations you want. You can find some example configuration files in this repository.

Configuration file

When you run the main.py file, the program will aks for a configuration file. The configuration file has to be a json file. There is an example.json file in this repository. These are the supported translations:

• angle: turn left
• draw: draw a line
• forward: move forward without drawing a line
• nop: do nothing
• push: push the current drawing state on the stack
• pop: replace the current drawing state with the one on top of the stack
• color: change the color from this point to the given name

with every translation, there is a value or variable:

• angle: amount of degrees
• draw: amount of pixels
• forward: amount of pixels
• nop: value doesn't matter
• push: value doesn't matter
• pop: value doens't matter
• color: name of the color you want, without capitals

History

A history.txt file will be created in the directory 'logs' when running the main.py for the first time. Every time you run the program, a new line will be added with the configuration information, timestamp and generated l-string.

History backups

If you wish, you can make backups on a hourly rate with the bash script backup.sh. Add the following to your crontab (command crontab -e, replace /path/to/the/project with the path to the project):

0 * * * * cd /path/to/the/project/ && ./backup.sh >/dev/null 2>&1

Restoring a history backup

There is a Python script restore.py that you can run if you wish to restore the history database to one of its backups. Simply run the script with the following command:

python3 restore.py

The script will show you all the possible history backups, you have to pick one and the chosen history backup will be copied in place of the current history file.

Exporting the drawing

Currently, only .eps files are supported. You can export the drawed l-system with the following command:

python3 main.py --export <filename>

Replace <filename> with the name of the file you want, followed by the extension .eps.

Web server

You can view the information and a svg image of your latest drawing with the following commands:

export FLASK_APP=webPage
flask run

Access the webpage with this url: http://localhost:5000/index.

Docker

You can build a docker image and run a docker container with the project files. Important: in order for docker to show you the drawing, you should first run the following commands:

LINUX

sudo apt-get install x11-xserver-utils

xhost +

MACOS (thanks to this gist)

1. install XQuartz
2. launch XQuartz, under the XQuartz menu, select Preferences
3. go to security tab and ensure "allow connections from network clients" is checked
4. run the following commands

xhost + ${hostname}
export HOSTNAME='your_hostname.local'

Docker container

Then you can start with docker:

cd /path/to/project

docker build -t l-system:latest

docker run --rm -ti -v ~/.l-system-logs:/logs \
		    -v /tmp/.X11-unix:/tmp/.X11-unix \
                    -e DISPLAY=$DISPLAY \
		    l-system:latest

On macOS you should change $DISPLAY to ${HOSTNAME}:0 Now the container will ask you the configuration file and the number of iterations.