feat: Position traits + GameObject.pos()

add equality/hash traits to Position so that it can be used as keys in
collections such as HashSet

give every GameObject a pos() method which returns Position

src/game/pathfinder.rs

@@ -1,13 +1,43 @@
 use js_sys::{Array, Object};
 use serde::{Deserialize, Serialize};
+use std::fmt;
 use wasm_bindgen::prelude::*;
 
-#[derive(Serialize, Deserialize, Debug)]
+#[derive(Serialize, Deserialize, Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Position {
     pub x: u8,
     pub y: u8,
 }
 
+impl fmt::Display for Position {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "[pos {},{}]", self.x, self.y)
+    }
+}
+
+impl Position {
+    pub fn range_to(&self, pos: &Position) -> u8 {
+        let diff_x = if self.x > pos.x {
+            self.x - pos.x
+        } else {
+            pos.x - self.x
+        };
+        let diff_y = if self.y > pos.y {
+            self.y - pos.y
+        } else {
+            pos.y - self.y
+        };
+
+        std::cmp::max(diff_x, diff_y)
+    }
+}
+
+impl From<Position> for JsValue {
+    fn from(pos: Position) -> JsValue {
+        serde_wasm_bindgen::to_value(&pos).expect("serializable Position")
+    }
+}
+
 #[wasm_bindgen(module = "game/path-finder")]
 extern "C" {
     /// Find an optimal path between origin and goal. Note that searchPath

src/objects/impls/game_object.rs

@@ -1,5 +1,5 @@
 use crate::{
-    game::pathfinder::{FindPathOptions, SearchResults},
+    game::pathfinder::{FindPathOptions, Position, SearchResults},
     prelude::*,
 };
 use js_sys::{Array, JsString, Object};
@@ -79,6 +79,13 @@ impl GameObject {
             }
         }
     }
+
+    pub fn pos(&self) -> Position {
+        Position {
+            x: self.x(),
+            y: self.y(),
+        }
+    }
 }
 
 impl<T> GameObjectProperties for T
@@ -101,6 +108,10 @@ where
         GameObject::y(self.as_ref())
     }
 
+    fn pos(&self) -> Position {
+        GameObject::pos(self.as_ref())
+    }
+
     fn ticks_to_decay(&self) -> Option<u32> {
         GameObject::ticks_to_decay(self.as_ref())
     }

src/traits.rs

@@ -3,7 +3,7 @@ use js_sys::{Array, JsString, Object};
 
 use crate::{
     enums::*,
-    game::pathfinder::{FindPathOptions, SearchResults},
+    game::pathfinder::{FindPathOptions, Position, SearchResults},
     objects::*,
 };
 
@@ -152,6 +152,8 @@ pub trait GameObjectProperties {
     /// The Y coordinate in the room.
     fn y(&self) -> u8;
 
+    fn pos(&self) -> Position;
+
     /// If defined, then this object will disappear after this number of ticks.
     fn ticks_to_decay(&self) -> Option<u32>;