raylib-clj

A Clojure Game Engine wrapping the fantastic Raylib library with the Project Panama Clojure wrapper Coffi

Requirements

You must have at least Java 17 to use the new Project Panama and Raylib installed as a system-level dynamic library. We can probably ship binaries eventually.

Structure

The main structure of this library follows that of raylib, but organized into namespaced-functional blocks following the cheatsheet. Function names follow the raylib names, but formatted to the clojure-friendly kebab-case style. Functions that mutate global state will end with a bang (!) and those that return bools end in ?. For example, the function to initialize the window and OpenGL context is in the core module in the window namespace, so it would be raylib.core.window/init-window!

Example

(ns basic-window
  (:require
   [raylib.core.window :as rcw]
   [raylib.core.timing :as rct]
   [raylib.core.drawing :as rcd]
   [raylib.text.drawing :as rtd]
   [raylib.colors :as colors]))

(def screen-width 800)
(def screen-height 450)

(defn -main []
  (rcw/init-window! screen-width screen-height "raylib [core] example - basic window")
  (rct/set-target-fps! 60)
  ;; Main Game Loop
  (while (not (rcw/window-should-close?))
    (rcd/begin-drawing!)
    (rcd/clear-background! colors/raywhite)
    (rtd/draw-text! "Congrats! You created your first window!" 190 200 20 colors/lightgray)
    (rcd/end-drawing!))
  (rcw/close-window!))

To run any of the included examples, use

clj -M:dev -m examples.x.y

such as

clj -M:dev -m examples.core.basic-window

for the above example.

Benchmarks

To bench our wrapper, we will compare against the tried and true bunnymark. Most other wrappers target this as well, so it'll be nice to compare. As expected, we are about 4x slower than the pure Java JNI approach and quite a bit slower than pure-C. To be fair, you would use instancing for something like this as we are putting FFI calls in the tight inner loop, which ends up being our bottleneck here.

Language	Bunnies @ 60 FPS	Speed
C (Reference)	216200	1x
Jaylib	64700	0.3x
raylib-clj	16000	0.07x