PyWeek 35

The theme for this PyWeek is In The Shadows.

Instructions

git clone https://github.com/guidopetri/the-shady-wood
cd the-shady-wood
pip install -r requirements.txt  # or replace with your virtual env stuff
python3 src/run_game.py

Install the dependencies with pip install, then run run_game.py from any location!

How to play

Menus

Press any key to advance.

Game

Use the arrow keys to move.

Use items with the C, F and S keys.

Game description

Anne was going for a picnic at her usual favorite spot, but when she arrived, she accidentally angered a fairy! The angry fairy cast a spell on her and transported her to the middle of the cursed forest known as the Shady Wood.

Help Anne find her way out of the Shady Wood. If she becomes too scared, she'll be turned to stone and be lost forever!

Some helpful items can be found around the forest, but be sure to use them carefully... people say the forest changes every time you enter it!

Lessons

state as a class with property setters

Keeping track of state is hard. In this game, we used a config module that contained a lot of different state-related defaults, and managed state by changing the values in a variable that was passed around. This was incredibly inconvenient: making sure that the game state was consistent had to be done in several different parts of the code, and it was easy to create bugs by forgetting to keep a consistent game state.

One alternative idea is to use a class or an object with property setters/ getters to manage state. This way, consistent state can be kept by ensuring the class implements correctness, and the object can be called forth in any module without having to worry about bugs creeping up if something is forgotten.

property setters to maintain consistency

Hand-in-hand with the above point, maintaining consistency is hard. Some variables can only have certain values, and using an enum is too much for how simple that variable is; and sometimes, variables are parts of objects and it's difficult to use an enum. Property setters can ensure consistency and enforce rules for setting variables.

single-surface, multiple-objects blitting on it is great

Previously, we had tried using multiple surfaces and blitting different things on them to then switch which surface was being displayed. This is probably a pretty natural idea to start with, but a much better idea is to use a single surface that is being displayed, and to blit things on it depending on what's required. By blitting things in the correct order, we can ensure that the image looks as it should to the player.

tuples for action/item combinations of spritesheets

Spritesheets can come in many different flavors, and keeping track of all the spritesheets as individual variables is annoying. One potential improvement is to use tuples or dictionaries instead to select the correct spritesheet as required. One even better idea is to use a spreadsheet class that can keep track of its own fps and looping, and exposes a stable API that makes interacting with a spritesheet much easier than keeping track of which frame you're on!

use placeholder images that get replaced as assets get ready

This one should have been obvious, but as the artist takes time to create art, it's useful to use placeholder images instead so that the coder doesn't have to wait for the artist before implementing anything image-related.

use utils file with mixin classes, e.g. for loading spritesheets

Mixin classes can implement specific methods on "child" classes that can help with reducing code duplication. For example, loading a spritesheet is pretty standard; we don't really need to have that code everywhere in each object, we can just use a mixin instead.

maybe keep track of first frame of each effect for calculating things

Calculating how long an effect is, or side effects of an action, means that it's easy to calculate things as an offset of the first instance instead of just having a counter that counts down.

separate music vs sfx folder

Also in the obvious territory, but having separate folders for music vs sound effects is very useful so that you don't have to keep track of what kind of file a file is!

music is not scary

Pygame makes it super easy to add music, and it's really not that bad, even though I was totally anxious about it.

Build instructions

Make sure pyinstaller is installed:

pip install pyinstaller

Create the spec file:

pyi-makespec --windowed --onefile --add-data "./assets;assets" --name shady_wood src/run_game.py

Use a ; for a path separator on Windows, or : on *nix.

Build:

pyinstaller --clean shady_wood.spec

The executable will be located in ./dist/shady_wood.exe (or no extension for *nix).

Credits / Attribution

Programming: Guido Petri

Art: Kendra Lemon

Music and sound effects: Kendra Lemon

Font: Dogica Pixel by Roberto Mocci.