Cookbook

Recipes for making games with KKE, from your first line of Lua to pathfinding, procedural animation and inverse kinematics. Each one is a small, complete piece of working code with a picture of it running.

How to use a recipe

Most recipes are one Lua file. Make a game from the starter template (Make your own game), start it, and save the recipe into its scripts/ folder: it runs the moment you save, and again every time you change it. Every recipe has a download link, and works in the starter game's level as it is.

Some recipes are C++, in the cookbook game (games/cookbook, run it as ./cookbook from build/bin). It is the starter game plus every common camera and an animated mannequin; the pages quote its code.

The chapters go from simplest to most involved:

Chapter	You'll learn
First steps	Variables, if, loops, functions and tables, each spawning something you can see; timers
Input	Your own controls, hold and release, reading the standard actions, binding keys and pads in C++
Moving things	Tuning the character, a ball you steer, a pet that follows you, patrols, launch pads
Cameras	First person, third person, orbit, top-down, isometric, side-on, fixed and cinematic cameras; screen shake
Gameplay	Trigger zones and doors, shooting with rays, explosions, a full round with a HUD, a timer and a saved best
Algorithms	Maze generation, terrain from noise, A* pathfinding, flocking
Animation and IK	Procedural motion, springs, two-bone IK, blend spaces, look-at and foot placement on a skeleton
Physics	Bounce and friction, things that really break, physics from C++
Sound	Sound materials, impact sounds, playing your own
Multiplayer	Host and player scripts, messages, a shared scoreboard
Play to make	The same game logic three ways: pictures, a node graph, and Lua
C++	Your own module, your own Lua bindings, testing your code

New to Lua? It's a small language; Programming in Lua is the classic introduction, and the Lua API reference lists everything the engine adds. Scripting in Lua explains hooks, timers, hot reload and the sandbox.

Why the recipes don't go stale

Documentation is only useful when it's right. Every recipe here is checked by CI on every change to the engine:

• The Lua recipes are real files (docs/cookbook/recipes/), shown on these pages as they are. CI starts the starter game headless with each one (tools/docs_site/run_recipes.py) and fails on any script error; the unit tests also compile every one of them.
• The C++ on these pages is quoted from files that are compiled into the cookbook game and the unit tests (tests/test_cookbook.cpp), which run it and check it does what the page says.
• The play-to-make Lua runs in the unit tests against the same building blocks the sandbox uses.

The screenshots come from the same runs: tools/docs_site/run_recipes.py --shots takes a picture of each recipe running and saves it here.