☄️ Comet

a free and open source game engine

Warning

This project is in early development and is not yet ready for use.

It could be potentially used to make something very basic in a very hacky way, but it is not a good experience.

Installation is manual as of right now but if it reaches an acceptable state I will publish the crate on crates.

There is a plan for a project creation tool that will automate the project setup process.

Recommended setup

The project structure as of right now should look like this:

project
│   Cargo.toml
│   build.rs
│   crates
│   └── comet
│   res
│   └── shaders
│   └── textures
│   └── sounds
│   src
│   └── main.rs

# Cargo.toml
# ...
[dependencies]
comet = { path = "path/of/the/comet/crate" }
# ...

// main.rs example
use comet::prelude::*;

struct GameState {}

impl GameState {
    pub fn new() -> Self {
      Self {}
    }
}

// This function will be called once before the event loop starts
fn setup(app: &mut App, renderer: &mut Renderer2D) {}
// This function will be called every tick
fn update(app: &mut App, renderer: &mut Renderer2D, dt: f32) {}

fn main() {
    App::new() // Generate a basic 2D app
        .with_preset(App2D) // Pre-registers the `Transform2D` component in the scene
        .with_title("Comet App") // Sets the window title
        .with_icon(r"res/textures/comet_icon.png") // Sets the window icon
        .with_size(1920, 1080) // Sets the window size
        .with_game_state(GameState::new()) // Adds a custom game state struct
        .run::<Renderer2D>(setup, update) // Starts app with the given
}

// build.rs example

use anyhow::*;
use fs_extra::copy_items;
use fs_extra::dir::CopyOptions;
use std::env;
use std::path::PathBuf;

fn main() -> Result<()> {
  // Watch resource directories for changes
  println!("cargo:rerun-if-changed=res/materials/*");
  println!("cargo:rerun-if-changed=res/objects/*");
  println!("cargo:rerun-if-changed=res/textures/*");
  println!("cargo:rerun-if-changed=res/shaders/*");
  println!("cargo:rerun-if-changed=res/data/*");
  println!("cargo:rerun-if-changed=res/sounds/*");
  println!("cargo:rerun-if-changed=res/fonts/*");

  let profile = env::var("PROFILE")?;
  let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR")?);
  let target_dir = manifest_dir.join("target").join(&profile);

  let dest_resources_dir = target_dir.join("res");

  std::fs::create_dir_all(&dest_resources_dir)?;

  let mut copy_options = CopyOptions::new();
  copy_options.overwrite = true;
  copy_options.copy_inside = true;

  let resource_folders = vec![
    "res/materials/",
    "res/objects/",
    "res/textures/",
    "res/shaders/",
    "res/data/",
    "res/sounds/",
    "res/fonts/",
  ];

  let resource_paths: Vec<PathBuf> = resource_folders
          .iter()
          .map(|p| manifest_dir.join(p))
          .collect();

  copy_items(&resource_paths, &dest_resources_dir, &copy_options)?;

  Ok(())
}