feat(game): implement pause system with Escape key and visual overlay

pacman/src/game.rs

@@ -541,9 +541,9 @@ impl Game {
             ))
             .configure_sets((
                 GameplaySet::Input,
-                GameplaySet::Update.run_if(|paused: Res<PauseState>| paused.active()),
-                GameplaySet::Respond.run_if(|paused: Res<PauseState>| paused.active()),
-                RenderSet::Animation.run_if(|paused: Res<PauseState>| paused.active()),
+                GameplaySet::Update.run_if(|paused: Res<PauseState>| !paused.active()),
+                GameplaySet::Respond.run_if(|paused: Res<PauseState>| !paused.active()),
+                RenderSet::Animation.run_if(|paused: Res<PauseState>| !paused.active()),
                 RenderSet::Draw,
                 RenderSet::Present,
             ));

pacman/src/systems/hud/score.rs

@@ -1,11 +1,12 @@
 use crate::constants;
 use crate::error::{GameError, TextureError};
-use crate::systems::{BackbufferResource, GameStage, ScoreResource, StartupSequence};
+use crate::systems::{BackbufferResource, GameStage, PauseState, ScoreResource, StartupSequence};
 use crate::texture::sprite::SpriteAtlas;
 use crate::texture::text::TextTexture;
 use bevy_ecs::event::EventWriter;
 use bevy_ecs::system::{NonSendMut, Res};
 use sdl2::pixels::Color;
+use sdl2::rect::Rect;
 use sdl2::render::Canvas;
 use sdl2::video::Window;
 
@@ -17,6 +18,7 @@ pub fn hud_render_system(
     mut atlas: NonSendMut<SpriteAtlas>,
     score: Res<ScoreResource>,
     stage: Res<GameStage>,
+    pause_state: Res<PauseState>,
     mut errors: EventWriter<GameError>,
 ) {
     let _ = canvas.with_texture_canvas(&mut backbuffer.0, |canvas| {
@@ -82,5 +84,28 @@ pub fn hud_render_system(
                 }
             }
         }
+
+        // Render pause overlay when game is paused (allowed during any stage)
+        if pause_state.active() {
+            // Enable blending for transparency
+            canvas.set_blend_mode(sdl2::render::BlendMode::Blend);
+            
+            // Draw semi-transparent black overlay
+            canvas.set_draw_color(Color::RGBA(0, 0, 0, 160));
+            let _ = canvas.fill_rect(Rect::new(0, 0, constants::CANVAS_SIZE.x, constants::CANVAS_SIZE.y));
+
+            // Render "PAUSED" text centered and larger (2.5x scale)
+            let mut paused_renderer = TextTexture::new(2.5);
+            let paused_text = "PAUSED";
+            let paused_width = paused_renderer.text_width(paused_text);
+            let paused_height = paused_renderer.text_height();
+            let paused_position = glam::UVec2::new(
+                (constants::CANVAS_SIZE.x - paused_width) / 2,
+                (constants::CANVAS_SIZE.y - paused_height) / 2
+            );
+            if let Err(e) = paused_renderer.render_with_color(canvas, &mut atlas, paused_text, paused_position, Color::YELLOW) {
+                errors.write(TextureError::RenderFailed(format!("Failed to render PAUSED text: {}", e)).into());
+            }
+        }
     });
 }

pacman/src/systems/input.rs

@@ -81,7 +81,7 @@ impl Default for Bindings {
         key_bindings.insert(Keycode::D, GameCommand::MovePlayer(Direction::Right));
 
         // Game actions
-        key_bindings.insert(Keycode::P, GameCommand::TogglePause);
+        key_bindings.insert(Keycode::Escape, GameCommand::TogglePause);
         key_bindings.insert(Keycode::Space, GameCommand::ToggleDebug);
         key_bindings.insert(Keycode::M, GameCommand::MuteAudio);
         key_bindings.insert(Keycode::R, GameCommand::ResetLevel);
@@ -89,7 +89,6 @@ impl Default for Bindings {
 
         #[cfg(not(target_os = "emscripten"))]
         {
-            key_bindings.insert(Keycode::Escape, GameCommand::Exit);
             key_bindings.insert(Keycode::Q, GameCommand::Exit);
             // Desktop-only fullscreen toggle
             key_bindings.insert(Keycode::F, GameCommand::ToggleFullscreen);

pacman/src/systems/state.rs

@@ -68,7 +68,7 @@ pub enum PauseState {
 
 impl Default for PauseState {
     fn default() -> Self {
-        Self::Active { remaining_ticks: None }
+        Self::Inactive
     }
 }