#+title: Fornax
#+subtitle: Collection of tools to visualize Path Finding Algorithms
#+export_file_name: index
#+options: toc:2
#+startup: overview
#+setupfile: ~/.emacs.d/org-templates/projects.org

| Website         | https://andinus.unfla.me/projects/fornax |
| Source          | https://git.unfla.me/fornax              |
| GitHub (mirror) | https://github.com/andinus/fornax        |

This collection includes:
- ~fornax~: Program that parses /Fornax Format/ and outputs video solution.
- Algorithms: Various algorithms solved in several programming
  languages.

Writings:
- Fornax: Generating 4.8 million frames:
  https://andinus.unfla.me/writings/2021/fornax-generating-4.8-million-frames.html

* Demo

Solution for DFS-60, generated on 2021-11-16 (click to play):

[[https://andinus.unfla.me/resources/projects/fornax/2021-11-16-DFS-60.mp4][https://andinus.unfla.me/resources/projects/fornax/2021-11-16-DFS-60-00000436.png]]
- Mirror: https://diode.zone/w/u6tuoktG1ZZWCQFZodKqyu

- Solution for /DFS-71/, generated on /2021-11-18/:
  https://diode.zone/w/vftEDZJWvBFxs9njBgHnV9

Fornax v0.1.0:
- Solution for /DFS-33/, generated on /2021-11-03/:
  https://andinus.unfla.me/resources/projects/fornax/2021-11-03-DFS-33.mp4
- DFS-51-incomplete (upto 187,628 frames; 120 fps):
  https://diode.zone/w/4RSFatXPL3GrkUucnFdxVS
- DFS-51-incomplete (upto 4,000 frames; 120 fps):
  https://diode.zone/w/hWWaw8uKHCP5weUP5WWArD

* Usage

#+begin_src sh
# Solve the maze.
raku algorithms/raku/DFS.raku resources/input/06 > /tmp/solution.fornax

# Visualize the solution.
raku -Ilib bin/fornax /tmp/solution.fornax
#+end_src

* Installation

~fornax~ is written in Raku, it can be installed with ~zef~. You can also
run it without ~zef~,  just run ~raku -Ilib bin/fornax~ from within the
source directory.

- *Note*: ~Cairo~ module & ~ffmpeg~ program is required.

** Release

1. Run ~zef install 'fornax:auth<zef:andinus>'~

Fornax should be installed, try running ~fornax --version~ to confirm.

- Solving programs / solutions are not included in the distribution, get
  them from this repository.

** From Source

You can either download the release archive generated by cgit/GitHub or
clone the project if you have ~git~ installed.

*** Without ~git~

1. Download the release:
   - https://git.unfla.me/fornax
   - https://github.com/andinus/fornax/releases
2. Extract the file.
3. Run ~zef install .~ in source directory.

*** With ~git~

All commits by /Andinus/ will be signed by this [[https://andinus.nand.sh/static/D9AE4AEEE1F1B3598E81D9DFB67D55D482A799FD.asc][PGP Key]].

#+begin_src sh
# Clone the project.
git clone https://git.tilde.institute/andinus/fornax
cd fornax

# Install fornax.
zef install .
#+end_src

* Documentation

Fornax parses /Fornax format/, generates a ~PNG~ for each iteration which is
later converted to a slideshow with ~ffmpeg~.

- Solved paths are highlighted if the iteration is preceded by ~|~.
- Illegal paths are highlighted if the iteration is preceded by ~!~.

** Options

- ~input~: This takes solved input file in the /Fornax/ format.
- ~fps~: Frame rate for the video solution.
- ~skip-video~: Skip generating the video solution.
- ~batch~: Number of iterations to process at once.

** Fornax Format

Fornax format defines 2 formats:
- Maze (input)
- Solution (output)

*** Grids

A grid is printed for every iteration. Grids are composed of cells.

| Cell             | Symbol |
|------------------+--------|
| Path             | ~.~      |
| Blocked          | ~#~      |
| Start            | ~^~      |
| Destination      | ~$~      |
|------------------+--------|
| Visited          | ~-~      |
| Current Path     | ~~~      |
| Current Position | ~@~      |

*** Maze (input)

Maze input must be in this format:
#+begin_src
...rows
#+end_src

It is upto the program to infer the number of rows & columns from the
input file or it ask the user.

*** Solution (output)

Fornax solution format is an intermediate output file generated after
solving the maze. Algorithms must output the solution in this format:
#+begin_src
rows:<number of rows> cols:<number of columns>

...iterations
#+end_src

~...iterations~ is to be replaced by the resulting grid in each iteration
that is to be included in the final video. Since the number of rows and
columns is known, the whole grid should be printed in a single line.

- Every iteration should be separated by a newline.

- If the iteration cells is not equal to ~rows * columns~ or ~(rows *
  columns) + 1~ then it may be ignored by the program that parses the
  file.

- Solved iteration can be preceded by ~|~ character.

- Iteration that tries to walk on a blocked path can be preceded by ~!~
  character.

- First iteration is assumed to be the maze.

** Project Structure

- Algorithms are located in ~algorithms/~ directory, sub-directory needs
  to be created for programming languages which will hold the actual
  source.

- Sample solutions can be found in ~resources/solutions/~ directory.

  - *Note*: Some solutions might output illegal moves (like walking over
    blocked path), this error is only in visualization, the solution is
    correct.

    This has been fixed in commit
    ~8cef86f0eb8b46b0ed2d7c37fa216890300249f6~.

* Bugs

- If the number of iterations are greater than an 8 digit number then
  the slideshow might be incorrect.

- ~/tmp~ is assumed to exist.

- Might panic with: ~MoarVM oops: MVM_str_hash_entry_size called with a
  stale hashtable pointer~. This has been fixed:
  https://github.com/rakudo/rakudo/pull/4634.

* News

** v0.2.0 - 2021-11-25

+ Add demo videos.
+ Add more solutions.
+ Implement BFS in Java.
+ Implement DFS in Raku.
+ Add basic tests.

** v0.1.1 - 2021-11-16

+ Add option to skip generating slideshow.
+ Use random directory to store solutions.
+ Process iterations in parallel.
+ Wait 4s on solution frame.
+ Add incomplete BFS program.
+ Add demo videos.
+ Upgrade to latest Fornax Format.
+ Add more solutions.

** v0.1.0 - 2021-11-03

+ Initial implementation:

  - Includes DFS solver in Java and a tool to visualize the solution.