space-crush/space-crush-app/src/debug/raster.rs

use glc::vector::{Vector2f, Vector4f};
use space_crush_common::resources::Raster as RasterResource;
use specs::{prelude::*, ReadExpect, System, World, WriteExpect};

use crate::resources::Geometry;

#[derive(Default)]
pub struct Raster;

#[derive(SystemData)]
pub struct FleetData<'a> {
    geometry: WriteExpect<'a, Geometry>,
    raster: ReadExpect<'a, RasterResource>,
}

impl<'a> System<'a> for Raster {
    type SystemData = FleetData<'a>;

    fn run(&mut self, data: Self::SystemData) {
        let FleetData {
            mut geometry,
            raster,
        } = data;

        let s = raster.size();

        gl::enable(gl::BLEND);
        gl::blend_func(gl::SRC_ALPHA, gl::ONE);

        for (x, y, q) in raster.quads() {
            let a = if q.is_empty() { 0.05 } else { 0.5 };

            geometry.render_lines(
                Vector4f::new(1.0, 1.0, 1.0, a),
                &create_quad(x as _, y as _, s),
            );
        }

        gl::disable(gl::BLEND);
    }
}

fn create_quad(x: f32, y: f32, s: f32) -> Vec<Vector2f> {
    let f = s / 2.0;
    vec![
        Vector2f::new(x * s + f, y * s + f),
        Vector2f::new(x * s + f, y * s - f),
        Vector2f::new(x * s - f, y * s - f),
        Vector2f::new(x * s - f, y * s + f),
        Vector2f::new(x * s + f, y * s + f),
    ]
}