Logika

What is Logika?

Logika (Logic in Esperanto) is a FSM (finite state machine) implementation for Ren’Py, FSM have a draw (graphic) that is a representation of the logic and the flow of process (label for Ren’Py).

This is a FSM draw

Why to use?

Well, when your history/game have very complex paths, is more easy only change the logic, with that you can concentrate in the writing process. For example you need to add a new scene between two scenes, that need to check the code and validate that don’t break the code, but with FSM (Logika) you only change the logic add a new line and change one.

The logic before change:

IF scene_old1 SEND next GOTO scene_old2
IF scene_old2 SEND next GOTO scene_old3

The logic after change:

IF scene_old1 SEND next GOTO scene_new1
IF scene_new1 SEND next GOTO scene_old2
IF scene_old2 SEND next GOTO scene_old3

How to use?

First, circle in the figure is a script (label and its content), arrows are how they move (flow) and the pharse to continue (return value), for exmple "CH1" is.

label ch1:
a "bla bla bla"
return "next"

In the "script.rpy" write this.

Label start:
 $ logic_game=FSM_logic()
     $ state=logic_game.logic("")
     call expression state
     while (_return!="gracias"): #key phrase to finish
         $ state=logic_game.logic(_return)
         call expression state
         # $ print logic_game.read_logger()
     return

Logika, create the rpy class with the logic you write it.

The logic for the FSM draw is:

START Prologue
IF Prologue SEND next GOTO ch1
IF ch1 SEND next GOTO ch2_beginnig
IF ch2_beginng SEND next GOTO path1a
IF ch2_beginng SEND next2 GOTO path2a
IF ch2_beginng SEND next3 GOTO path3a
IF path1a SEND next GOTO path1b
IF path1b SEND back GOTO path1a
...
...

for this you can use:

START "start scene name"

IF "scene name" SEND "transition condition1" OR "transition condition2" GOTO "scene name2"

START, start

IF, if

SEND, send

GOTO, goto

License

This work is under a Creative Commons Attribution 4.0 International License.

Version 1.0

• Binary
• Source code (python3)

Version 1.0.2

• Source code (Python 3) https://github.com/badanni/Logika
• fix problem with lexer and token
• graphviz for draw the FSM

pip install PyQt5

import graphviz_standalone as gv

import graphviz as gv

pip install graphviz

python FSM_logic.py

python FSM_logic.pyw