convert ant into slime with trail

src/ant.rs

@@ -1,4 +1,6 @@
-use crate::constants::{ANT_SPEED, FLOOR_COLOR};
+use crate::constants::ANT_SPEED;
+use crate::constants::MAP_HEIGHT;
+use crate::constants::MAP_WIDTH;
 use crate::Drawable;
 use macroquad::prelude::*;
 use macroquad::rand::RandomRange;
@@ -15,27 +17,31 @@ impl Ant {
         (0..num)
             .into_iter()
             .map(|n| Ant {
-                pos: Vec2::new(400., 200.),
+                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, map_data: &Image) {
+    pub(crate) fn walk(&mut self, frame_time: f32, trail_map: &mut Image) {
         let new_dir = PI / 8. * RandomRange::gen_range(-2, 2) as f32;
         self.dir += new_dir;
-        self.dir = self.dir.clamp(0., PI * 2.);
+        if self.dir > 2. * PI {
+            self.dir -= 2. * PI;
+        }
 
         let acceleration = Vec2::new(self.dir.sin(), -self.dir.cos());
-        let new_pos = self.pos + acceleration * ANT_SPEED * get_frame_time();
-        let dest_pixel = map_data.get_pixel(new_pos.x as u32, new_pos.y as u32);
-        if dest_pixel == FLOOR_COLOR {
-            self.pos = new_pos;
-        }
+        self.pos += acceleration * ANT_SPEED * frame_time;
+        // TODO: this is not fixing out of bounds write
+        self.pos.x = self.pos.x.clamp(0., MAP_WIDTH as f32);
+        self.pos.y = self.pos.y.clamp(0., MAP_HEIGHT as f32);
+
+        // TODO: change color over time
+        trail_map.set_pixel(self.pos.x as u32, self.pos.y as u32, RED);
     }
 }
 
 impl Drawable for Ant {
     fn draw(&self) {
-        draw_circle(self.pos.x, self.pos.y, 1., BLACK);
+        draw_circle(self.pos.x, self.pos.y, 1., WHITE);
     }
 }

src/constants.rs

@@ -1,6 +1,3 @@
-use macroquad::color::Color;
-
 pub static ANT_SPEED: f32 = 20.;
-pub static FLOOR_COLOR: Color = Color::new(0.46666667, 0.38431373, 0.3019608, 1.);
-pub static SCREEN_WIDTH: i32 = 1280;
-pub static SCREEN_HEIGHT: i32 = 720;
+pub const MAP_WIDTH: u32 = 1280;
+pub const MAP_HEIGHT: u32 = 720;

src/food.rs

@@ -7,6 +7,7 @@ pub(crate) struct Food {
     pos: Vec2,
 }
 
+#[allow(dead_code)]
 impl Food {
     pub(crate) fn new(pos: Vec2) -> Self {
         Food { pos }

src/main.rs

@@ -1,18 +1,19 @@
+extern crate macroquad;
+
 mod ant;
 mod constants;
 mod food;
 
 use crate::ant::Ant;
-use crate::constants::{SCREEN_HEIGHT, SCREEN_WIDTH};
-use crate::food::Food;
+use constants::{MAP_HEIGHT, MAP_WIDTH};
 use macroquad::prelude::*;
 
 fn window_conf() -> Conf {
     Conf {
         window_title: "Ants".to_string(),
         fullscreen: false,
-        window_width: SCREEN_WIDTH,
-        window_height: SCREEN_HEIGHT,
+        window_width: MAP_WIDTH as i32,
+        window_height: MAP_HEIGHT as i32,
         ..Default::default()
     }
 }
@@ -23,27 +24,39 @@ trait Drawable {
 
 #[macroquad::main(window_conf)]
 async fn main() {
-    let map = load_texture("map_scaled.png").await.unwrap();
-    let map_data = map.get_texture_data();
-    let mut ants = Ant::init(16);
-    let mut food = Food::init();
+    //let map = load_texture("map_scaled.png").await.unwrap();
+    let mut trail_map = Image::gen_image_color(MAP_WIDTH as u16, MAP_HEIGHT as u16, BLACK);
+    let mut ants = Ant::init(1024);
 
     loop {
+        // fade trails (doesnt really work)
+        let frame_time = get_frame_time();
+        for x in 0..MAP_WIDTH {
+            for y in 0..MAP_HEIGHT {
+                let mut current_pixel = trail_map.get_pixel(x, y);
+                current_pixel.r -= 0.1 * frame_time;
+                current_pixel.g -= 0.1 * frame_time;
+                current_pixel.b -= 0.1 * frame_time;
+                trail_map.set_pixel(x, y, current_pixel);
+            }
+        }
         // actions
-        ants.iter_mut().for_each(|ant| ant.walk(&map_data));
+        ants.iter_mut()
+            .for_each(|ant| ant.walk(frame_time, &mut trail_map));
         if is_key_down(KeyCode::Escape) || is_quit_requested() {
             return;
         }
         if is_mouse_button_down(MouseButton::Left) {
             let mouse = mouse_position();
-            food.push(Food::new(Vec2::new(mouse.0, mouse.1)));
+            dbg!(&mouse);
+            //food.push(Food::new(Vec2::new(mouse.0, mouse.1)));
         }
 
         // render
-        clear_background(BEIGE);
-        draw_texture(map, 0., 0., WHITE);
+        clear_background(BLACK);
+        let texture = Texture2D::from_image(&trail_map);
+        draw_texture(texture, 0., 0., WHITE);
         ants.iter().for_each(|ant| ant.draw());
-        food.iter().for_each(|food| food.draw());
 
         next_frame().await
     }