From 723c2fe0982f80438b75098fa79d1933efc13d0a Mon Sep 17 00:00:00 2001
From: salmonik <salmonik@tuta.io>
Date: Sat, 11 Jul 2026 15:30:04 +0200
Subject: add enemy AI: chase, patrol, attack, and movement animation

---
 src/renderer.rs | 117 +++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 69 insertions(+), 48 deletions(-)

(limited to 'src/renderer.rs')

diff --git a/src/renderer.rs b/src/renderer.rs
index aa87b54..885e5de 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -74,6 +74,18 @@ pub struct Renderer {
     floor_dist_lut: Vec<f64>,
 }
 
+// ---- entity sprites ---------------------------------------------------
+
+/// Screen-space info for an entity sprite to render.
+struct Sprite {
+    sx: isize,
+    sy: isize,
+    scale: f64,
+    ch: char,
+    color: u32,
+    cam_z: f64,
+}
+
 impl Renderer {
     pub fn new(screen_w: usize, screen_h: usize) -> Self {
         let half_h = screen_h as f64 / 2.0;
@@ -306,19 +318,9 @@ impl Renderer {
     ) {
         let mw = game.maze.width();
         let mh = game.maze.height();
-
-        // Collect visible entities with their screen info.
-        struct Sprite {
-            sx: isize,
-            sy: isize,
-            scale: f64,
-            ch: char,
-            color: u32,
-            cam_z: f64,
-        }
-
         let mut sprites: Vec<Sprite> = Vec::new();
 
+        // Static entities on the grid.
         for y in 0..mh {
             for x in 0..mw {
                 let entity = match game.maze.entity_at(x, y) {
@@ -329,46 +331,15 @@ impl Renderer {
                 let ex = x as f64 + 0.5;
                 let ey = y as f64 + 0.5;
 
-                let dx = ex - game.player.x;
-                let dy = ey - game.player.y;
-
-                let fx = game.player.angle.cos();
-                let fy = game.player.angle.sin();
-                let rx = -fy;
-                let ry = fx;
-
-                let cam_z = dx * fx + dy * fy;
-                if cam_z <= 0.1 {
-                    continue;
-                }
-
-                let cam_x = dx * rx + dy * ry;
-
-                let half_fov_tan = (fov / 2.0).tan();
-                let screen_x_norm = cam_x / (cam_z * half_fov_tan);
-                if screen_x_norm < -1.0 || screen_x_norm > 1.0 {
-                    continue;
-                }
-
-                let sx = ((screen_x_norm + 1.0) * 0.5 * self.screen_w as f64) as isize;
-
-                let entity_h = (self.screen_h as f64 / cam_z * 0.4) as isize;
-                let sy = (half_h - entity_h as f64 * 0.3) as isize;
-
-                let scale = (entity_h.max(6) as f64 / LETTER_H as f64).max(0.5);
-                let (ch, color) = entity_char_and_color(entity);
-
-                sprites.push(Sprite {
-                    sx,
-                    sy,
-                    scale,
-                    ch,
-                    color,
-                    cam_z,
-                });
+                self.push_entity_sprite(game, ex, ey, entity, fov, half_h, &mut sprites);
             }
         }
 
+        // Animating enemies (mid-move, not on the grid).
+        for (wx, wy, entity) in game.enemy_render_entities() {
+            self.push_entity_sprite(game, wx, wy, &entity, fov, half_h, &mut sprites);
+        }
+
         // Sort farthest first so nearby entities draw on top.
         sprites.sort_by(|a, b| b.cam_z.partial_cmp(&a.cam_z).unwrap());
 
@@ -387,6 +358,56 @@ impl Renderer {
         }
     }
 
+    /// Project a world-space entity position and push a Sprite if on screen.
+    fn push_entity_sprite(
+        &self,
+        game: &Game,
+        ex: f64,
+        ey: f64,
+        entity: &Entity,
+        fov: f64,
+        half_h: f64,
+        sprites: &mut Vec<Sprite>,
+    ) {
+        let dx = ex - game.player.x;
+        let dy = ey - game.player.y;
+
+        let fx = game.player.angle.cos();
+        let fy = game.player.angle.sin();
+        let rx = -fy;
+        let ry = fx;
+
+        let cam_z = dx * fx + dy * fy;
+        if cam_z <= 0.1 {
+            return;
+        }
+
+        let cam_x = dx * rx + dy * ry;
+
+        let half_fov_tan = (fov / 2.0).tan();
+        let screen_x_norm = cam_x / (cam_z * half_fov_tan);
+        if screen_x_norm < -1.0 || screen_x_norm > 1.0 {
+            return;
+        }
+
+        let sx = ((screen_x_norm + 1.0) * 0.5 * self.screen_w as f64) as isize;
+
+        let entity_h = (self.screen_h as f64 / cam_z * 0.4) as isize;
+        let sy = (half_h - entity_h as f64 * 0.3) as isize;
+
+        let scale = (entity_h.max(6) as f64 / LETTER_H as f64).max(0.5);
+        let (ch, color) = entity_char_and_color(entity);
+
+        sprites.push(Sprite {
+            sx,
+            sy,
+            scale,
+            ch,
+            color,
+            cam_z,
+        });
+    }
+
     fn draw_char_scaled(
         &self,
         buffer: &mut [u32],
-- 
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