feat: enhance debug visuals with cursor-based effect

src/map/render.rs

@@ -1,6 +1,8 @@
 //! Map rendering functionality.
 
 use crate::texture::sprite::{AtlasTile, SpriteAtlas};
+use crate::texture::text::TextTexture;
+use glam::Vec2;
 use sdl2::pixels::Color;
 use sdl2::rect::{Point, Rect};
 use sdl2::render::{Canvas, RenderTarget};
@@ -23,45 +25,93 @@ impl MapRenderer {
         let _ = map_texture.render(canvas, atlas, dest);
     }
 
-    /// Renders a debug visualization of the navigation graph.
+    /// Renders a debug visualization with cursor-based highlighting.
     ///
-    /// This function is intended for development and debugging purposes. It draws the
-    /// nodes and edges of the graph on top of the map, allowing for visual
-    /// inspection of the navigation paths.
-    pub fn debug_render_nodes<T: RenderTarget>(graph: &crate::entity::graph::Graph, canvas: &mut Canvas<T>) {
+    /// This function provides interactive debugging by highlighting the nearest node
+    /// to the cursor, showing its ID, and highlighting its connections.
+    pub fn debug_render_with_cursor<T: RenderTarget>(
+        graph: &crate::entity::graph::Graph,
+        canvas: &mut Canvas<T>,
+        text_renderer: &mut TextTexture,
+        atlas: &mut SpriteAtlas,
+        cursor_pos: Vec2,
+    ) {
+        // Find the nearest node to the cursor
+        let nearest_node = Self::find_nearest_node(graph, cursor_pos);
+
+        // Draw all connections in blue
+        canvas.set_draw_color(Color::RGB(0, 0, 128)); // Dark blue for regular connections
         for i in 0..graph.node_count() {
             let node = graph.get_node(i).unwrap();
             let pos = node.position + crate::constants::BOARD_PIXEL_OFFSET.as_vec2();
 
-            // Draw connections
-            canvas.set_draw_color(Color::BLUE);
-
             for edge in graph.adjacency_list[i].edges() {
                 let end_pos = graph.get_node(edge.target).unwrap().position + crate::constants::BOARD_PIXEL_OFFSET.as_vec2();
                 canvas
                     .draw_line((pos.x as i32, pos.y as i32), (end_pos.x as i32, end_pos.y as i32))
                     .unwrap();
             }
+        }
+
+        // Draw all nodes in green
+        canvas.set_draw_color(Color::RGB(0, 128, 0)); // Dark green for regular nodes
+        for i in 0..graph.node_count() {
+            let node = graph.get_node(i).unwrap();
+            let pos = node.position + crate::constants::BOARD_PIXEL_OFFSET.as_vec2();
 
-            // Draw node
-            // let color = if pacman.position.from_node_idx() == i.into() {
-            //     Color::GREEN
-            // } else if let Some(to_idx) = pacman.position.to_node_idx() {
-            //     if to_idx == i.into() {
-            //         Color::CYAN
-            //     } else {
-            //         Color::RED
-            //     }
-            // } else {
-            //     Color::RED
-            // };
-            canvas.set_draw_color(Color::GREEN);
             canvas
                 .fill_rect(Rect::new(0, 0, 3, 3).centered_on(Point::new(pos.x as i32, pos.y as i32)))
                 .unwrap();
+        }
 
-            // Draw node index
-            // text.render(canvas, atlas, &i.to_string(), pos.as_uvec2()).unwrap();
+        // Highlight connections from the nearest node in bright blue
+        if let Some(nearest_id) = nearest_node {
+            let nearest_pos = graph.get_node(nearest_id).unwrap().position + crate::constants::BOARD_PIXEL_OFFSET.as_vec2();
+
+            canvas.set_draw_color(Color::RGB(0, 255, 255)); // Bright cyan for highlighted connections
+            for edge in graph.adjacency_list[nearest_id].edges() {
+                let end_pos = graph.get_node(edge.target).unwrap().position + crate::constants::BOARD_PIXEL_OFFSET.as_vec2();
+                canvas
+                    .draw_line(
+                        (nearest_pos.x as i32, nearest_pos.y as i32),
+                        (end_pos.x as i32, end_pos.y as i32),
+                    )
+                    .unwrap();
+            }
+
+            // Highlight the nearest node in bright green
+            canvas.set_draw_color(Color::RGB(0, 255, 0)); // Bright green for highlighted node
+            canvas
+                .fill_rect(Rect::new(0, 0, 5, 5).centered_on(Point::new(nearest_pos.x as i32, nearest_pos.y as i32)))
+                .unwrap();
+
+            // Draw node ID text (small, offset to top right)
+            text_renderer.set_scale(0.5); // Small text
+            let id_text = format!("#{}", nearest_id);
+            let text_pos = glam::UVec2::new(
+                (nearest_pos.x + 4.0) as u32, // Offset to the right
+                (nearest_pos.y - 6.0) as u32, // Offset to the top
+            );
+            let _ = text_renderer.render(canvas, atlas, &id_text, text_pos);
         }
     }
+
+    /// Finds the nearest node to the given cursor position.
+    pub fn find_nearest_node(graph: &crate::entity::graph::Graph, cursor_pos: Vec2) -> Option<usize> {
+        let mut nearest_id = None;
+        let mut nearest_distance = f32::INFINITY;
+
+        for i in 0..graph.node_count() {
+            let node = graph.get_node(i).unwrap();
+            let node_pos = node.position + crate::constants::BOARD_PIXEL_OFFSET.as_vec2();
+            let distance = cursor_pos.distance(node_pos);
+
+            if distance < nearest_distance {
+                nearest_distance = distance;
+                nearest_id = Some(i);
+            }
+        }
+
+        nearest_id
+    }
 }