ants/src/ant.rs

use crate::constants::*;
use macroquad::color::*;
use macroquad::math::Vec2;
use macroquad::prelude::Image;
use macroquad::rand::RandomRange;
use std::f32::consts::PI;

#[derive(Debug)]
pub(crate) struct Ant {
    pos: Vec2,
    dir: f32,
}

impl Ant {
    pub(crate) fn init(num: i32) -> Vec<Self> {
        let dir_steps = PI * 2. / num as f32;
        (0..num)
            .into_iter()
            .map(|n| Ant {
                pos: Vec2::new((MAP_WIDTH / 2) as f32, (MAP_HEIGHT / 2) as f32),
                dir: n as f32 * dir_steps,
            })
            .collect()
    }
    pub(crate) fn walk(&mut self, frame_time: f32, trail_map: &mut Image) {
        self.sense(trail_map);
        let new_dir = PI / 8. * RandomRange::gen_range(-2, 2) as f32;
        self.dir += new_dir;
        if self.dir > 2. * PI {
            self.dir -= 2. * PI;
        }

        let acceleration = Vec2::new(self.dir.sin(), -self.dir.cos());
        self.pos += acceleration * ANT_SPEED * frame_time;
        // if we are out of the map, turn around 180 degrees (or pi in radian)
        if self.pos.x < 0.0
            || self.pos.x >= (MAP_WIDTH - 1) as f32
            || self.pos.y < 0.0
            || self.pos.y >= (MAP_HEIGHT - 1) as f32
        {
            self.dir += PI;
        }
        self.pos.x = self.pos.x.clamp(0., (MAP_WIDTH - 1) as f32);
        self.pos.y = self.pos.y.clamp(0., (MAP_HEIGHT - 1) as f32);
    }
    fn sense(&self, trail_map: &mut Image) {
        trail_map.set_pixel(self.dir.sin() as u32, -self.dir.cos() as u32, YELLOW);
        trail_map.set_pixel(self.dir.sin() as u32, -self.dir.cos() as u32, YELLOW);
        trail_map.set_pixel(self.dir.sin() as u32, -self.dir.cos() as u32, YELLOW);
    }
    // TODO: change color over time or based on other factors
    pub(crate) fn draw(&self, trail_map: &mut Image) {
        let radius: i32 = 3;
        for x in -radius..radius {
            for y in -radius..radius {
                let x = (self.pos.x as i32 + x) as u32;
                let y = (self.pos.y as i32 + y) as u32;
                if x < (MAP_WIDTH - 1) && y < (MAP_HEIGHT - 1) {
                    trail_map.set_pixel(x, y, RED);
                }
            }
        }
    }
}