Dunge

Features

• Simple but flexible API
• Desktop, WASM and Android support
• Pixel perfect render with custom layers
• Texture and color vertex modes
• Primitives for object positioning and camera view out of the box

Application area

The library is for personal use only. I use it to create my applications and I make API suitable exclusively for my problems. Perhaps in the future API will settle down and the library will be self-sufficient for other applications.

Getting Started

Let's render a colorful triangle for example. First, we need to add the dependency of dunge in the Cargo.toml:

cargo add dunge

Then, let's create a new window to draw something in it:

// Import some types
use dunge::{
    color::Standard,
    handles::*,
    input::{Input, Key},
    transform::Position,
    vertex::ColorVertex,
    CanvasConfig, Context, Error, Frame, InitialState, Loop, MeshData, Perspective, View,
    WindowMode,
};

fn main() {
    dunge::make_window(InitialState::default())
        .run_blocking(CanvasConfig::default(), App::new)
        .into_panic();
}

make_window creates a new instance of Canvas type and sets up window properties, it allows us to handle an input from users. run_blocking runs our application by calling the constructor of it and passes the Context object there. Context uses for creation and updating of meshes, textures, views, instances etc.

The App is our application type, we need to create it:

struct App {
    layer: LayerHandle<ColorVertex>,
    instance: InstanceHandle,
    mesh: MeshHandle<ColorVertex>,
    view: ViewHandle,
}

impl App {
    fn new(context: &mut Context) -> Self {
        // Create new layer for `ColorVertex`. The vertex type inferred from the context
        let layer = context.create_layer();

        // Create a model instance
        let instance = context.create_instances([Position::default()]);

        // Create a mesh
        let mesh = {
            // Vertex data describes a position in XYZ coordinates and color in RGB per vertex:
            const VERTICES: [ColorVertex; 3] = [
                ColorVertex { pos: [-0.5, -0.5, 0.], col: [1., 0., 0.] },
                ColorVertex { pos: [ 0.5, -0.5, 0.], col: [0., 1., 0.] },
                ColorVertex { pos: [ 0.,   0.5, 0.], col: [0., 0., 1.] },
            ];
            let data = MeshData::from_verts(&VERTICES);
            context.create_mesh(&data)
        };

        // Create the view
        let view = context.create_view::<Perspective>(View::default());
        Self { layer, instance, mesh, view }
    }
}

To be able to pass the App in run_blocking we need to implement a Loop trait for it:

impl Loop for App {
    type Error = Error; // Define the error type

    // This calls once before every `render`
    fn update(&mut self, context: &mut Context, input: &Input) -> Result<(), Self::Error> {
        // You can update the context here. For example create and delete meshes.
        // Also you may want to handle an user's input here.
        Ok(())
    }

    // This calls every time the application needs to draw something in the window
    fn render(&self, frame: &mut Frame) -> Result<(), Self::Error> {
        // Draw a new layer
        let mut layer = frame
            .layer(self.layer)?
            .with_clear_color(Standard([0, 0, 0, u8::MAX]))
            .with_clear_depth()
            .start();

        layer.bind_view(self.view)?;
        layer.bind_instance(self.instance)?;
        layer.draw(self.mesh)
    }
}

Finally, let's run our code:

cargo run

Now you should see something like this:

Examples

See examples directory for more examples. To build and run an example do:

cargo r -p <example_name>