System configuration

To compile the *gamnit* apps packaged with the Nit repository on GNU/Linux you need to install the dev version of a few libraries and some tools. On Debian 8.2, this command should install everything needed: ~~~ apt-get install libgles2-mesa-dev libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev inkscape ~~~ On Windows 64 bits, using msys2, you can install the required packages with: ~~~ pacman -S mingw-w64-x86_64-angleproject-git mingw-w64-x86_64-SDL2 mingw-w64-x86_64-SDL2_image mingw-w64-x86_64-SDL2_mixer ~~~ While macOS isn't supported, it can create iOS apps. You need to install and setup Xcode, and you may install the GLSL shader validation tool via `brew`: ~~~ brew install glslang ~~~

Services by submodules

*gamnit* is modular, different services of the framework are available through different submodules: * The main entrypoint `gamnit` provides low-level abstractions over some services of OpenGL ES 2.0, like textures, shaders and programs. It defines the basic methods to implement in order to obtain a working game: `App::frame_core` to update the screen and `App::accept_event` to receive user inputs. * `flat` provides an easy to use API for 2D games based on sprites. Clients of this API redefine `App::update` to update the game logic and fill lists of sprites with objects to draw. `App::sprites` lists the sprites of the game world, they are drawn form the point of view of the `world_camera`. This camera can be moved around in the world by updating the x and y of its `position`, and the zoom can easily be set using `reset_depth(desired_world_units_on_y)` or the `z` of its `position` `App::ui_sprites` lists the UI sprites drawn from the point of view of `ui_camera`. By default, this camera is pixel-perfect with the origin in the top left corner of the window. However to support screens with different DPI, it is recommended to standardize the display size using `reset_depth(height_of_reference_display)`. * `depth` defines an API for 3D games based on instances of `Actor`. This framework is build upon `flat`, see the doc of this submodule first (just above). As such, clients should still implement `update` with the game logic, and fill `ui_sprites` for UI elements. At each frame, elements in the list `actors` are drawn to screen. Each `Actor` is composed of a `Model` and other information specific to this instance: position in the world, rotation and scaling. * `limit_fps` refines existing services of *gamnit* to limit the framerate to a customizable value. * `keys` provides `app.pressed_keys` keeping track of the currently pressed keys. * `model_parsers` provides services to read and parse models from the asset folder. * `network` provides a simple communication framework for multiplayer client/server games.