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Getting started

wick ships inside the lantern engine — there is nothing separate to install.

git clone https://github.com/alikatgh/lantern && cd lantern
brew install sdl2 lua cmake pkg-config    # macOS; Linux: same packages
cmake -B build && cmake --build build -j8

./build/lantern games/wicklab             # the first wick program
./build/lantern games/showcase_wick      # Kora Night, in wick

A game is a folder

A wick game is a directory containing main.wick. The host runs it when present (falling back to main.lua otherwise):

mkdir games/mygame
$EDITOR games/mygame/main.wick
./build/lantern games/mygame

Define two functions. The engine calls them at 60 fps:

fn update(dt: num) {   // dt = seconds since last frame (capped at 0.1)
}

fn draw() {            // 3D first, then 2D composites on top
  lt.clear(0.1, 0.1, 0.2)
  lt.print("HELLO 400X240", 4, 4, 1, 1, 1, 1)
}

Both are optional — a main.wick with only top-level statements is legal. Top-level statements run once, at load.

The dev loop

  • Hot reload: save main.wick while the engine runs; it recompiles and reloads live (all previous resources are freed first — reloading never leaks).
  • Error screen: a compile error (or runtime error, like an out-of-range index) renders in-engine with file:line: message. Fix the file, save, keep playing.
  • CI screenshots: LANTERN_SHOT=/tmp/x ./build/lantern games/mygame captures frame 60 as BMP and exits. Add LANTERN_FIXED_DT=1 and the capture is byte-identical on every machine — wick's rand() is deterministic too, so whole gameplay sessions replay exactly.

Package a game

./build/lantern_pack games/mygame mygame.lant
./build/lantern mygame.lant

Store packages require main.wick. Nested folders (assets/…) pack with relative paths. Loads refuse .. and absolute paths — see PACKAGE.md and the store-safety post.

Two minutes of syntax

let speed = 120.0            // types are inferred
let name: str = "tenzin"     // ...or written out
let lamps: list<bool> = []   // empty literals need the annotation

record Pt { x: num, y: num }
let p = Pt { x: 1, y: 2 }

for i in 0..4 {              // 0-based, end-exclusive
  push(lamps, true)
}

fn dim(v: num): num {        // parameter types are required
  if v < 0.5 { return 0 }    // conditions must be bool
  return v * 0.5
}

let saved = lt.load_save("hi")   // saved: str?  (an optional!)
let text = saved ?? "no save"    // ?? unwraps with a default
if saved != nil {
  lt.print(saved, 4, 4, 1, 1, 1, 1)  // narrowed to str inside the block
}

Read on: Syntax · Types & optionals · Records · Blog

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