Struct gemini_engine::elements3d::view3d::Viewport

pub struct Viewport {
    pub transform: Transform3D,
    pub fov: f64,
    pub origin: Vec2D,
    pub character_width_multiplier: f64,
}

The Viewport handles printing 3D objects to a 2D [View], and also acts as the scene’s camera.

Fields

transform: Transform3D

How the Viewport is oriented in the 3D scene

fov: f64

The Viewport’s field of view

origin: Vec2D

The center of the view you intend to print to. You can use View.center() as the input for this

character_width_multiplier: f64

Most terminals don’t have perfectly square characters. The value you set here is how much the final image will be stretched in the X axis to account for this. The default value is 2.2 but it will be different in most terminals

Implementations

impl Viewport

pub fn new(transform: Transform3D, fov: f64, origin: Vec2D) -> Self

Examples found in repository

examples/spinning-cube.rs (lines 15-19)

fn main() {
    let mut frame_skip = false;
    let mut view = View::new(350, 90, ColChar::BACKGROUND);

    let mut viewport = Viewport::new(
        Transform3D::new_tr(Vec3D::new(0.0, 0.0, 5.0), Vec3D::new(-0.5, 0.3, 0.0)),
        FOV,
        Vec2D::new((view.width / 2) as isize, (view.height / 2) as isize),
    );

    let cube = Mesh3D::default_cube();

    loop {
        let now = gameloop::Instant::now();
        view.clear();

        viewport.transform.rotation.y -= 0.05;

        match frame_skip {
            true => frame_skip = false,
            false => {
                view.blit(
                    &viewport.render(vec![&cube], DisplayMode::Solid),
                    Wrapping::Ignore,
                );
                view.display_render().unwrap();
            }
        }

        let elapsed = now.elapsed();
        println!(
            "Elapsed: {:.2?}µs | Frame skip: {}",
            elapsed.as_micros(),
            frame_skip
        );

        frame_skip = gameloop::sleep_fps(FPS, Some(elapsed));
    }
}

pub fn perspective(&self, pos: Vec3D) -> Vec2D

pub fn transform_vertices(&self, object: &impl ViewElement3D) -> Vec<Vec3D>

Return the object’s vertices, transformed

pub fn get_vertices_on_screen( &self, object: &impl ViewElement3D ) -> (Vec<Vec2D>, Vec<f64>)

Return the screen coordinates and distance from the view for each vertex, as parallel vectors

pub fn render( &self, objects: Vec<&impl ViewElement3D>, display_mode: DisplayMode ) -> PixelContainer

Examples found in repository

examples/spinning-cube.rs (line 33)

fn main() {
    let mut frame_skip = false;
    let mut view = View::new(350, 90, ColChar::BACKGROUND);

    let mut viewport = Viewport::new(
        Transform3D::new_tr(Vec3D::new(0.0, 0.0, 5.0), Vec3D::new(-0.5, 0.3, 0.0)),
        FOV,
        Vec2D::new((view.width / 2) as isize, (view.height / 2) as isize),
    );

    let cube = Mesh3D::default_cube();

    loop {
        let now = gameloop::Instant::now();
        view.clear();

        viewport.transform.rotation.y -= 0.05;

        match frame_skip {
            true => frame_skip = false,
            false => {
                view.blit(
                    &viewport.render(vec![&cube], DisplayMode::Solid),
                    Wrapping::Ignore,
                );
                view.display_render().unwrap();
            }
        }

        let elapsed = now.elapsed();
        println!(
            "Elapsed: {:.2?}µs | Frame skip: {}",
            elapsed.as_micros(),
            frame_skip
        );

        frame_skip = gameloop::sleep_fps(FPS, Some(elapsed));
    }
}