Glove is a framework for making games. It is implemented in Crystal.
⚠ Caution! ⚠ Glove is experimental. Expect breaking changes. There are few tests. Do not use this for your own projects (yet). (Or do, and contribute back to Glove? That’d be cool. I’ll give you commit access. You can be one of the first people to write a proper game engine in Crystal.)
To use this shard, add the following lines to your
dependencies: glove: git: firstname.lastname@example.org:ddfreyne/glove.git
Glove comes with shaders in its
shaders/ directory, which needs to be copied to where the executable is located. For example, the following will create a
target/ directory that contains the executable and the shaders directory:
rm -rf target/ mkdir -p target crystal build -o target/mygame src/mygame.cr cp -r lib/glove/src/shaders target/shaders
It is useful to let the executable
cd to the directory it is located in, before doing anything else, so that it can find the shaders easily:
if full_path = Process.executable_path Dir.cd(File.dirname(full_path)) end
target/ directory should also include any assets that the game needs to run; a more complete build script could therefore look as follows:
rm -rf target/ mkdir -p target crystal build -o target/mygame src/mygame.cr cp -r lib/glove/src/shaders target/shaders cp -r assets target/assets # <- added
Here is a trivial example that renders a card (from
require "glove" if full_path = Process.executable_path Dir.cd(File.dirname(full_path)) end card = Glove::Entity.new.tap do |e| e << Glove::Components::Texture.new("assets/card.png") e << Glove::Components::Transform.new.tap do |t| t.width = 140_f32 t.height = 190_f32 t.translate_x = 400_f32 t.translate_y = 300_f32 end end scene = Glove::Scene.new.tap do |scene| scene.spaces << Glove::Space.new.tap do |space| space.entities << card end end game = Glove::EntityApp.new(800, 600, "Inari") game.clear_color = Glove::Color::WHITE game.replace_scene(scene) game.run
Glove::EntityAppis a generic game superclass that provides functionality for handling entities, and everything associated with it. Here is how a typical game would build an instance and run the game:
game = Glove::EntityApp.new(800, 600, "Inari") game.clear_color = Glove::Color::WHITE scene = Glove::Scene.new.tap do |scene| # … build scene here … end game.replace_scene(scene) game.run
Glove::Entityis a game object that is visible and/or reacts to user input.
Glove::Componentis a property of an entity. A common component is
Glove::Components::Transform, which adds width, height, rotation, scale, … to an entity. Another common component is
Glove::Components::Camera, which marks an entity as being a camera, and defines which part of a space (see below) will be rendered, with what rotation, etc.
Glove::Actiondefines a change to an entity. It can either be instant (e.g. remove entity) or act over time (e.g. move).
Glove::Spacegroups entities in a scene that logically belong together and can interact with each other. Entities in different spaces never interact. For example, one space might contain the game entities, and another space might contain UI elements.
Glove::Scenedescribes a scene (such as the main menu, credits, or in-game screen). It contains one or more spaces.
Glove::Systemdescribes logic for making changes to a space. A common system is a physics system, which would calculate velocities and update positions.
There are also a handful of simple data classes:
This project started out by playing with crystal-gl by Gustavo Giráldez.