WIP

engine/lib/Signal.ts

@@ -0,0 +1,28 @@
+type Current = null | (() => void);
+
+let current: Current = null;
+
+export function createSignal<T>(value: T): [() => T, (value: T) => void] {
+	let innerValue = value;
+	const observers = new Set<() => void>();
+
+	const getter = () => {
+		current !== null && observers.add(current);
+
+		return innerValue;
+	};
+	const setter = (value: T) => {
+		innerValue = value;
+		for (const observer of observers) {
+			observer();
+		}
+	};
+
+	return [getter, setter];
+}
+
+export function createEffect(callback: () => void) {
+	current = callback;
+	callback();
+	current = null;
+}

engine/system/physics.ts

@@ -283,9 +283,9 @@ export function moveAndSlide(
 			continue; // TODO
 		}
 
-		const ts = Math.min(0, time - 0.001);
-		velocity.x += velocity.x * ts;
-		velocity.y += velocity.y * ts;
+		// const ts = Math.min(0, time - 0.001);
+		// velocity.x += velocity.x * ts;
+		// velocity.y += velocity.y * ts;
 
 		const dot = getDotProduct(velocity, collision.normal);
 		const rt = 1 - time + 0.001;

game/entities/hero/entity.ts

@@ -1,5 +1,6 @@
 import { defineEntity } from "#/engine/Entity.ts";
 import { keyboardInput } from "#/engine/Keyboard.ts";
+import { createEffect, createSignal } from "#/engine/lib/Signal.ts";
 import { pointer } from "#/engine/Pointer.ts";
 import { createRect } from "#/engine/Rect.ts";
 import $ from "#/engine/Scene.ts";
@@ -21,7 +22,7 @@ import {
 } from "#/engine/Vector.ts";
 import charIdle from "#/game/assets/char-idle.png";
 
-const speed = 0.1;
+const [speed, setSpeed] = createSignal(0.1);
 const idleSrc = await defineSpriteSheet(charIdle, 2, 4);
 
 const process = defineEntity("hero", {
@@ -32,6 +33,12 @@ const process = defineEntity("hero", {
 	collider: createCollider(Shape.Rect, createRect(createVector(), 16, 16)),
 });
 
+createEffect(() => {
+	console.log(speed());
+});
+
+let onceGuard = true;
+
 process((id, delta) => {
 	const position = $<Vector>("position").get(id)!.value;
 	const velocity = $<Vector>("velocity").get(id)!.value;
@@ -39,8 +46,15 @@ process((id, delta) => {
 	if (pointer.isDown) {
 		position.x = pointer.position.x;
 		position.y = pointer.position.y;
+
+		if (onceGuard) {
+			onceGuard = false;
+			setSpeed(0.1);
+		}
+
 		return;
 	}
+	onceGuard = true;
 
 	velocity.x -= keyboardInput.arrowLeft ? 1 : 0;
 	velocity.x += keyboardInput.arrowRight ? 1 : 0;
@@ -48,7 +62,7 @@ process((id, delta) => {
 	velocity.y += keyboardInput.arrowDown ? 1 : 0;
 
 	normalize(velocity);
-	scale(velocity, speed);
+	scale(velocity, speed());
 	moveAndSlide(id, velocity, delta);
 
 	position.x += velocity.x * delta;

game/scenes/testScene/data.json

@@ -17,7 +17,7 @@
 			"init": {
 				"position": {
 					"x": 24,
-					"y": 40
+					"y": 44
 				}
 			}
 		},