files.

ingredients/_basic-structure.ts

@@ -0,0 +1,57 @@
+import { Behavior, Vector2, Vector2Adapter } from "@dreamlab/engine";
+import { MAP_BOUNDARY } from "./_constants.ts";
+
+// example Behavior that allows for WASD movement as well as a pattern for firing projectiles.
+// this serves as an example for the general structure of a behavior
+class Movement extends Behavior {
+  // the speed of the player
+  speed = 5.0;
+  // the current velocity of the player
+  velocity = Vector2.ZERO;
+
+  #up = this.inputs.create("@movement/up", "Move Up", "KeyW");
+  #down = this.inputs.create("@movement/down", "Move Down", "KeyS");
+  #left = this.inputs.create("@movement/left", "Move Left", "KeyA");
+  #right = this.inputs.create("@movement/right", "Move Right", "KeyD");
+
+  onInitialize(): void {
+    // definevalue calls make the public class variables visible in the inspector GUI and also sync over the network
+    this.defineValue(Movement, "speed");
+    this.defineValue(Movement, "velocity", { type: Vector2Adapter });
+  }
+
+  onTick(): void {
+    const movement = new Vector2(0, 0);
+    const currentSpeed = this.speed;
+
+    if (this.#up.held) movement.y += 1;
+    if (this.#down.held) movement.y -= 1;
+    if (this.#right.held) movement.x += 1;
+    if (this.#left.held) movement.x -= 1;
+
+    this.velocity = movement
+      .normalize()
+      .mul((this.game.physics.tickDelta / 100) * currentSpeed);
+
+    const newPosition = this.entity.transform.position.add(this.velocity);
+
+    const halfWidth = this.entity.transform.scale.x / 2;
+    const halfHeight = this.entity.transform.scale.y / 2;
+
+    // don't move beyond the map boundaries
+    if (newPosition.x - halfWidth <= -MAP_BOUNDARY) newPosition.x = -MAP_BOUNDARY;
+    if (newPosition.x + halfWidth >= MAP_BOUNDARY) newPosition.x = MAP_BOUNDARY;
+
+    if (newPosition.y - halfHeight <= -MAP_BOUNDARY) newPosition.y = -MAP_BOUNDARY;
+    if (newPosition.y + halfHeight >= MAP_BOUNDARY) newPosition.y = MAP_BOUNDARY;
+
+    // make the entity this behavior is attached to face the player
+    const world = this.inputs.cursor.world;
+    if (!world) return;
+
+    const rotation = this.entity.transform.position.lookAt(world);
+    this.entity.transform.rotation = rotation;
+
+    this.entity.transform.position = newPosition;
+  }
+}