Saohime Engine is a Data-Oriented 2D game engine for Nim Programming Language.

Note

This project is under heavy development and NOT ready for practical use. Some features have not yet been implemented. See Roadmap for more details.

Supported platforms

• MacOS
• Linux (Ubuntu, NixOS)
• Windows (Haven't tested yet, but should work on it)

Requirement

• SDL, SDL_image, SDL_ttf (2.x)

Installation

nimble install https://github.com/glassesneo/saohime

Usage

import
  std/[random],
  saohime,
  saohime/default_plugins

proc setup(renderer: Resource[Renderer]) {.system.} =
  # Get the resource of type `Renderer`
  # It's a syntax sugar for `let renderer = commands.getResource(Renderer)`
  randomize()
  renderer.setDrawBlendMode(BlendModeBlend)

proc pollEvent(appEvent: Event[ApplicationEvent]) {.system.} =
  # Receive `ApplicationEvent` which deals with the application's start/stop
  for event in appEvent:
    if event.eventType == Quit:
      # `Application` itself is a resource.
      let app = commands.getResource(Application)
      app.terminate()

proc randomCircles(fpsManager: Resource[FPSManager]) {.system.} =
  if fpsManager.frameCount mod 20 == 0:
    let color = SaohimeColor.new(
      r = rand(255),
      g = rand(255),
      b = 255,
      a = rand(127),
    )
    # Create an entity
    commands.create()
      # Attach a component
      .attach(Circle.new(radius = 1))
      .attach(
        Transform.new(x = rand(640f), y = rand(480f), scale = Vector.new(1, 1)),
      )
      .attach(Material.new(color = color))

proc increaseRadius(
    # Get the entities which have `Circle` component
    circleQuery: [All[Circle]]
) {.system.} =
  for entity, circle in circleQuery[Circle]:
    circle.radius += 1
    if circle.radius > 150:
      entity.delete()

# Create an instance of `Application`
let app = Application.new()

# Load the default plugins --------- it's necessary to create a window!
app.loadPluginGroup(DefaultPlugins)

# Start the app
app.start:
  # In the block of `start`, you can use a special variable `world`
  # to add or register what you need for your app.
  world.registerStartupSystems(setup)
  world.registerSystems(pollEvent, randomCircles, increaseRadius)

See examples/ for more practical examples.

Features/Roadmap

Basic features

• Entity Component System integration with ecslib
• GPU rendering with SDL2
• Instant rendering with z-order
• Flexible API for image, sprite and tile map
• 2D camera implementation
• 3D Audio operations with OpenAL via slappy
• Efficient asset management
• Event queue implementation well-integrated with ECS
• General input device support including game controller
• Simple FPS management
• Hierarchical structure between entities
• Particle implementation
• GUI implementation built on ECS
• Support for TUI
• Timer implementation
• Command line tool
• Save/Load implementation

Extra features

• Extensible plugin architecture
• Lua integration via spellua
• Resource embedding
• Test and debug tool
• WebAssembly support
• OpenGL integration
• cairo integration
• Hot reload

Documentation

Please go see ecslib for Entity Component System API. The core application API reference can be seen here. Every default plugin will soon have its own API.md.

Plugins

Official

• Audio Plugin
• Lua Plugin

The reference for the plugin architecture in Saohime can be seen here.

License

Saohime Engine is licensed under the MIT license. See COPYING for details.