feat: draw lines between the stations

src/algorithm/objects/line.rs

@@ -1,3 +1,4 @@
+use wasm_bindgen::JsValue;
 use web_sys::CanvasRenderingContext2d;
 
 use super::{Drawable, Station};
@@ -23,8 +24,67 @@ impl Line {
 
 impl Drawable for Line {
     fn draw(&self, canvas: &CanvasRenderingContext2d, square_size: u32) {
-        for station in self.get_stations() {
-            station.draw(canvas, square_size)
+        let offset = square_size as f64 / 3.0 - 2.0;
+        let stations = self.get_stations();
+
+        canvas.set_line_width(2.0);
+        canvas.set_stroke_style(&JsValue::from_str("black"));
+        canvas.begin_path();
+
+        if stations.len() > 1 {
+            for (start_station, end_station) in stations.iter().zip(stations.iter().skip(1)) {
+                let (from_x, from_y) =
+                    station_corner_closest(start_station, end_station, square_size, offset);
+                canvas.move_to(from_x, from_y);
+
+                let (to_x, to_y) =
+                    station_corner_closest(end_station, start_station, square_size, offset);
+                canvas.line_to(to_x, to_y);
+            }
+        } else if stations.len() == 1 {
+            let (station_x, station_y) = stations[0].get_canvas_pos(square_size);
+
+            canvas.move_to(station_x - offset, station_y);
+            canvas.line_to(station_x - (square_size as f64 - offset), station_y);
+
+            canvas.move_to(station_x + offset, station_y);
+            canvas.line_to(station_x + (square_size as f64 - offset), station_y);
+        }
+
+        canvas.stroke();
+    }
+}
+
+fn station_corner_closest(
+    station: &Station,
+    neighbor: &Station,
+    square_size: u32,
+    offset: f64,
+) -> (f64, f64) {
+    let (station_x, station_y) = station.get_canvas_pos(square_size);
+    let (neighbor_x, neighbor_y) = neighbor.get_canvas_pos(square_size);
+
+    if station_x == neighbor_x {
+        if station_y > neighbor_y {
+            (station_x, station_y - offset) // below
+        } else {
+            (station_x, station_y + offset) // above
+        }
+    } else if station_x > neighbor_x {
+        if station_y == neighbor_y {
+            (station_x - offset, station_y) // left
+        } else if station_y > neighbor_y {
+            (station_x - offset, station_y - offset) // below left
+        } else {
+            (station_x - offset, station_y + offset) // above left
+        }
+    } else {
+        if station_y == neighbor_y {
+            (station_x + offset, station_y) // right
+        } else if station_y > neighbor_y {
+            (station_x + offset, station_y - offset) // below right
+        } else {
+            (station_x + offset, station_y + offset) // above right
         }
     }
 }

src/algorithm/objects/map.rs

@@ -58,6 +58,9 @@ impl Map {
 
 impl Drawable for Map {
     fn draw(&self, canvas: &web_sys::CanvasRenderingContext2d, square_size: u32) {
+        for station in self.get_stations() {
+            station.draw(canvas, square_size)
+        }
         for line in self.lines.iter() {
             line.draw(canvas, square_size)
         }

src/algorithm/objects/station.rs

@@ -49,6 +49,10 @@ impl Station {
         self.pos.set(pos);
     }
 
+    pub fn get_canvas_pos(&self, square_size: u32) -> (f64, f64) {
+        calc_canvas_loc(self.get_pos(), square_size)
+    }
+
     pub fn clone_non_ref(&self) -> Self {
         Self {
             id: self.id,
@@ -60,7 +64,7 @@ impl Station {
 
 impl Drawable for Station {
     fn draw(&self, canvas: &CanvasRenderingContext2d, square_size: u32) {
-        let canvas_pos = calc_canvas_loc(self.get_pos(), square_size);
+        let canvas_pos = self.get_canvas_pos(square_size);
 
         canvas.set_line_width(4.0);
         if self.is_ghost {
@@ -72,7 +76,7 @@ impl Drawable for Station {
             .arc(
                 canvas_pos.0,
                 canvas_pos.1,
-                (square_size / 3) as f64,
+                square_size as f64 / 3.0,
                 0.0,
                 2.0 * f64::consts::PI,
             )

src/components/sidebar.rs

@@ -37,5 +37,7 @@ fn testmap() -> Map {
         Station::new((30, 20)),
     ]));
 
+    map.add_line(Line::new(vec![Station::new((7, 5))]));
+
     map
 }