survivors: only displaying the controls if we are on mobile

adding method to detect if mobile

absurd-survivors/src/ui.ts

@@ -1,34 +1,44 @@
 import type {Drawable, DrawContainer, MouseInteracting, MouseInterActingContainer} from "./interfaces.ts";
 import {World} from "./World.ts";
 import {Vector} from "./base.ts";
-import {drawDot, fillDot, rectPointIntersection} from "./utils.ts";
+import {drawDot, fillDot, isMobile, rectPointIntersection} from "./utils.ts";
 
 export class HUD implements DrawContainer {
     private health: PlayerInfo;
-    private controls: Controls;
+    private controls: Controls | undefined;
     private world: World;
 
     constructor(world: World, keys: any) {
         this.world = world;
         this.health = new PlayerInfo(world);
-        this.controls = new Controls(world, keys);
+        if (isMobile()) {
+            this.controls = new Controls(world, keys);
+        }
     }
 
     draw(ctx: CanvasRenderingContext2D) {
         this.health.draw(ctx)
-        this.controls.draw(ctx)
+        if(this.controls) {
+            this.controls.draw(ctx)
+        }
     }
 
     mouseDown(pos: Vector) {
-        this.controls.mouseDown(pos)
+        if(this.controls) {
+            this.controls.mouseDown(pos)
+        }
     }
 
     mouseUp(pos: Vector) {
-        this.controls.mouseUp(pos)
+        if(this.controls) {
+            this.controls.mouseUp(pos)
+        }
     }
 
     mouseMove(pos: Vector) {
-        this.controls.mouseMove(pos)
+        if(this.controls) {
+            this.controls.mouseMove(pos)
+        }
     }
 
 }

absurd-survivors/src/utils.ts

@@ -7,6 +7,10 @@ export function fillDot(position: Vector, size: number, color: string, ctx: Canv
     ctx.fill();
 }
 
+export function isMobile() {
+    return /iPhone|iPad|iPod|Android/i.test(navigator.userAgent);
+}
+
 export function drawDot(position: Vector, size: number, color: string, ctx: CanvasRenderingContext2D) {
     ctx.beginPath();
     ctx.strokeStyle = color;