feat: add drag reference control relaxation with easing, mild refactor

Justfile

@@ -41,4 +41,4 @@ samply:
 
 # Build the project for Emscripten
 web:
-    bun run web.build.ts
+    bun run web.build.ts; caddy file-server --root dist

src/game.rs

@@ -13,6 +13,7 @@ use crate::systems::blinking::Blinking;
 use crate::systems::components::{GhostAnimation, GhostState, LastAnimationState};
 use crate::systems::movement::{BufferedDirection, Position, Velocity};
 use crate::systems::profiling::SystemId;
+use crate::systems::render::touch_ui_render_system;
 use crate::systems::render::RenderDirty;
 use crate::systems::{
     self, combined_render_system, ghost_collision_system, present_system, Hidden, LinearAnimation, MovementModifiers, NodeId,
@@ -108,9 +109,9 @@ impl Game {
             EventType::ControllerTouchpadDown,
             EventType::ControllerTouchpadMotion,
             EventType::ControllerTouchpadUp,
-            EventType::FingerDown,
-            EventType::FingerUp,
-            EventType::FingerMotion,
+            // EventType::FingerDown,  // Enable for touch controls
+            // EventType::FingerUp,    // Enable for touch controls
+            // EventType::FingerMotion, // Enable for touch controls
             EventType::DollarGesture,
             EventType::DollarRecord,
             EventType::MultiGesture,
@@ -130,9 +131,8 @@ impl Game {
             EventType::Window,
             EventType::MouseWheel,
             // EventType::MouseMotion,
-            EventType::MouseButtonDown,
-            EventType::MouseButtonUp,
-            EventType::MouseButtonDown,
+            // EventType::MouseButtonDown,  // Enable for desktop touch testing
+            // EventType::MouseButtonUp,    // Enable for desktop touch testing
             EventType::AppDidEnterBackground,
             EventType::AppWillEnterForeground,
             EventType::AppWillEnterBackground,
@@ -159,7 +159,7 @@ impl Game {
         // Create debug texture at output resolution for crisp debug rendering
         let output_size = canvas.output_size().unwrap();
         let mut debug_texture = texture_creator
-            .create_texture_target(None, output_size.0, output_size.1)
+            .create_texture_target(Some(sdl2::pixels::PixelFormatEnum::ARGB8888), output_size.0, output_size.1)
             .map_err(|e| GameError::Sdl(e.to_string()))?;
 
         // Debug texture is copied over the backbuffer, it requires transparency abilities
@@ -317,6 +317,7 @@ impl Game {
         world.insert_resource(DebugState::default());
         world.insert_resource(AudioState::default());
         world.insert_resource(CursorPosition::default());
+        world.insert_resource(systems::input::TouchState::default());
         world.insert_resource(StartupSequence::new(
             constants::startup::STARTUP_FRAMES,
             constants::startup::STARTUP_TICKS_PER_FRAME,
@@ -388,6 +389,7 @@ impl Game {
                 dirty_render_system,
                 combined_render_system,
                 hud_render_system,
+                touch_ui_render_system,
                 present_system,
             )
                 .chain(),

src/platform/emscripten.rs

@@ -29,6 +29,7 @@ pub fn requires_console() -> bool {
     false
 }
 
+#[allow(dead_code)]
 pub fn get_canvas_size() -> Option<(u32, u32)> {
     let mut width = 0.0;
     let mut height = 0.0;

src/systems/input.rs

@@ -15,6 +15,12 @@ use crate::{
     map::direction::Direction,
 };
 
+// Touch input constants
+const TOUCH_DIRECTION_THRESHOLD: f32 = 10.0;
+const TOUCH_EASING_DISTANCE_THRESHOLD: f32 = 1.0;
+const MAX_TOUCH_MOVEMENT_SPEED: f32 = 100.0;
+const TOUCH_EASING_FACTOR: f32 = 1.5;
+
 #[derive(Resource, Default, Debug, Copy, Clone)]
 pub enum CursorPosition {
     #[default]
@@ -25,6 +31,30 @@ pub enum CursorPosition {
     },
 }
 
+#[derive(Resource, Default, Debug)]
+pub struct TouchState {
+    pub active_touch: Option<TouchData>,
+}
+
+#[derive(Debug, Clone)]
+pub struct TouchData {
+    pub finger_id: i64,
+    pub start_pos: Vec2,
+    pub current_pos: Vec2,
+    pub current_direction: Option<Direction>,
+}
+
+impl TouchData {
+    pub fn new(finger_id: i64, start_pos: Vec2) -> Self {
+        Self {
+            finger_id,
+            start_pos,
+            current_pos: start_pos,
+            current_direction: None,
+        }
+    }
+}
+
 #[derive(Resource, Debug, Clone)]
 pub struct Bindings {
     key_bindings: HashMap<Keycode, GameCommand>,
@@ -125,12 +155,62 @@ pub fn process_simple_key_events(bindings: &mut Bindings, frame_events: &[Simple
     emitted_events
 }
 
+/// Calculates the primary direction from a 2D vector delta
+fn calculate_direction_from_delta(delta: Vec2) -> Direction {
+    if delta.x.abs() > delta.y.abs() {
+        if delta.x > 0.0 {
+            Direction::Right
+        } else {
+            Direction::Left
+        }
+    } else if delta.y > 0.0 {
+        Direction::Down
+    } else {
+        Direction::Up
+    }
+}
+
+/// Updates the touch reference position with easing
+///
+/// This slowly moves the start_pos towards the current_pos, with the speed
+/// decreasing as the distance gets smaller. The maximum movement speed is capped.
+/// Returns the delta vector and its length for reuse by the caller.
+fn update_touch_reference_position(touch_data: &mut TouchData, delta_time: f32) -> (Vec2, f32) {
+    // Calculate the vector from start to current position
+    let delta = touch_data.current_pos - touch_data.start_pos;
+    let distance = delta.length();
+
+    // If there's no significant distance, nothing to do
+    if distance < TOUCH_EASING_DISTANCE_THRESHOLD {
+        return (delta, distance);
+    }
+
+    // Calculate speed based on distance (slower as it gets closer)
+    // The easing function creates a curve where movement slows down as it approaches the target
+    let speed = (distance / TOUCH_EASING_FACTOR).min(MAX_TOUCH_MOVEMENT_SPEED);
+
+    // Calculate movement distance for this frame
+    let movement_amount = speed * delta_time;
+
+    // If the movement would overshoot, just set to target
+    if movement_amount >= distance {
+        touch_data.start_pos = touch_data.current_pos;
+    } else {
+        // Use direct vector scaling instead of normalization
+        let scale_factor = movement_amount / distance;
+        touch_data.start_pos += delta * scale_factor;
+    }
+
+    (delta, distance)
+}
+
 pub fn input_system(
     delta_time: Res<DeltaTime>,
     mut bindings: ResMut<Bindings>,
     mut writer: EventWriter<GameEvent>,
     mut pump: NonSendMut<EventPump>,
     mut cursor: ResMut<CursorPosition>,
+    mut touch_state: ResMut<TouchState>,
 ) {
     let mut cursor_seen = false;
     // Collect all events for this frame.
@@ -159,6 +239,43 @@ pub fn input_system(
                     remaining_time: 0.20,
                 };
                 cursor_seen = true;
+
+                // Handle mouse motion as touch motion for desktop testing
+                if let Some(ref mut touch_data) = touch_state.active_touch {
+                    touch_data.current_pos = Vec2::new(x as f32, y as f32);
+                }
+            }
+            // Handle mouse events as touch for desktop testing
+            Event::MouseButtonDown { x, y, .. } => {
+                let pos = Vec2::new(x as f32, y as f32);
+                touch_state.active_touch = Some(TouchData::new(0, pos)); // Use ID 0 for mouse
+            }
+            Event::MouseButtonUp { .. } => {
+                touch_state.active_touch = None;
+            }
+            // Handle actual touch events for mobile
+            Event::FingerDown { finger_id, x, y, .. } => {
+                // Convert normalized coordinates (0.0-1.0) to screen coordinates
+                let screen_x = x * crate::constants::CANVAS_SIZE.x as f32;
+                let screen_y = y * crate::constants::CANVAS_SIZE.y as f32;
+                let pos = Vec2::new(screen_x, screen_y);
+                touch_state.active_touch = Some(TouchData::new(finger_id, pos));
+            }
+            Event::FingerMotion { finger_id, x, y, .. } => {
+                if let Some(ref mut touch_data) = touch_state.active_touch {
+                    if touch_data.finger_id == finger_id {
+                        let screen_x = x * crate::constants::CANVAS_SIZE.x as f32;
+                        let screen_y = y * crate::constants::CANVAS_SIZE.y as f32;
+                        touch_data.current_pos = Vec2::new(screen_x, screen_y);
+                    }
+                }
+            }
+            Event::FingerUp { finger_id, .. } => {
+                if let Some(ref touch_data) = touch_state.active_touch {
+                    if touch_data.finger_id == finger_id {
+                        touch_state.active_touch = None;
+                    }
+                }
             }
             Event::KeyDown { keycode, repeat, .. } => {
                 if let Some(key) = keycode {
@@ -188,6 +305,25 @@ pub fn input_system(
         writer.write(event);
     }
 
+    // Update touch reference position with easing
+    if let Some(ref mut touch_data) = touch_state.active_touch {
+        // Apply easing to the reference position and get the delta for direction calculation
+        let (delta, distance) = update_touch_reference_position(touch_data, delta_time.0);
+
+        // Check for direction based on updated reference position
+        if distance >= TOUCH_DIRECTION_THRESHOLD {
+            let direction = calculate_direction_from_delta(delta);
+
+            // Only send command if direction has changed
+            if touch_data.current_direction != Some(direction) {
+                touch_data.current_direction = Some(direction);
+                writer.write(GameEvent::Command(GameCommand::MovePlayer(direction)));
+            }
+        } else if touch_data.current_direction.is_some() {
+            touch_data.current_direction = None;
+        }
+    }
+
     if let (false, CursorPosition::Some { remaining_time, .. }) = (cursor_seen, &mut *cursor) {
         *remaining_time -= delta_time.0;
         if *remaining_time <= 0.0 {

src/systems/render.rs

@@ -1,6 +1,7 @@
 use crate::constants::CANVAS_SIZE;
 use crate::error::{GameError, TextureError};
 use crate::map::builder::Map;
+use crate::systems::input::TouchState;
 use crate::systems::{
     debug_render_system, BatchedLinesResource, Collider, CursorPosition, DebugState, DebugTextureResource, DeltaTime,
     DirectionalAnimation, LinearAnimation, Position, Renderable, ScoreResource, StartupSequence, SystemId, SystemTimings,
@@ -114,6 +115,79 @@ pub struct MapTextureResource(pub Texture);
 /// A non-send resource for the backbuffer texture. This just wraps the texture with a type so it can be differentiated when exposed as a resource.
 pub struct BackbufferResource(pub Texture);
 
+/// Renders touch UI overlay for mobile/testing.
+pub fn touch_ui_render_system(
+    mut backbuffer: NonSendMut<BackbufferResource>,
+    mut canvas: NonSendMut<&mut Canvas<Window>>,
+    touch_state: Res<TouchState>,
+    mut errors: EventWriter<GameError>,
+) {
+    if let Some(ref touch_data) = touch_state.active_touch {
+        let _ = canvas.with_texture_canvas(&mut backbuffer.0, |canvas| {
+            // Set blend mode for transparency
+            canvas.set_blend_mode(BlendMode::Blend);
+
+            // Draw semi-transparent circle at touch start position
+            canvas.set_draw_color(Color::RGBA(255, 255, 255, 100));
+            let center = Point::new(touch_data.start_pos.x as i32, touch_data.start_pos.y as i32);
+
+            // Draw a simple circle by drawing filled rectangles (basic approach)
+            let radius = 30;
+            for dy in -radius..=radius {
+                for dx in -radius..=radius {
+                    if dx * dx + dy * dy <= radius * radius {
+                        let point = Point::new(center.x + dx, center.y + dy);
+                        if let Err(e) = canvas.draw_point(point) {
+                            errors.write(TextureError::RenderFailed(format!("Touch UI render error: {}", e)).into());
+                            return;
+                        }
+                    }
+                }
+            }
+
+            // Draw direction indicator if we have a direction
+            if let Some(direction) = touch_data.current_direction {
+                canvas.set_draw_color(Color::RGBA(0, 255, 0, 150));
+
+                // Draw arrow indicating direction
+                let arrow_length = 40;
+                let (dx, dy) = match direction {
+                    crate::map::direction::Direction::Up => (0, -arrow_length),
+                    crate::map::direction::Direction::Down => (0, arrow_length),
+                    crate::map::direction::Direction::Left => (-arrow_length, 0),
+                    crate::map::direction::Direction::Right => (arrow_length, 0),
+                };
+
+                let end_point = Point::new(center.x + dx, center.y + dy);
+                if let Err(e) = canvas.draw_line(center, end_point) {
+                    errors.write(TextureError::RenderFailed(format!("Touch arrow render error: {}", e)).into());
+                }
+
+                // Draw arrowhead (simple approach)
+                let arrow_size = 8;
+                match direction {
+                    crate::map::direction::Direction::Up => {
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x - arrow_size, end_point.y + arrow_size));
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x + arrow_size, end_point.y + arrow_size));
+                    }
+                    crate::map::direction::Direction::Down => {
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x - arrow_size, end_point.y - arrow_size));
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x + arrow_size, end_point.y - arrow_size));
+                    }
+                    crate::map::direction::Direction::Left => {
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x + arrow_size, end_point.y - arrow_size));
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x + arrow_size, end_point.y + arrow_size));
+                    }
+                    crate::map::direction::Direction::Right => {
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x - arrow_size, end_point.y - arrow_size));
+                        let _ = canvas.draw_line(end_point, Point::new(end_point.x - arrow_size, end_point.y + arrow_size));
+                    }
+                }
+            }
+        });
+    }
+}
+
 /// Renders the HUD (score, lives, etc.) on top of the game.
 pub fn hud_render_system(
     mut backbuffer: NonSendMut<BackbufferResource>,