No more ecs

client/entity/entity.ts

@@ -0,0 +1,100 @@
+import type { ClientLevel } from "../level/client_level.ts";
+
+// anything that exists in the level and moves, like minecraft's Entity. position is the middle of its feet
+export abstract class Entity {
+	id: string;
+	level: ClientLevel;
+
+	x = 0;
+	y = 0;
+	z = 0;
+	// blocks per second
+	vx = 0;
+	vy = 0;
+	vz = 0;
+	yaw = 0;
+	pitch = 0;
+
+	// the collision box, width is used for both x and z
+	width: number;
+	height: number;
+	eye_height: number;
+	gravity = -15.8;
+
+	// which way it hit something on each axis in the last move: 1 or -1, 0 for nothing.
+	// 1 on y means it's standing on something
+	colliding_x = 0;
+	colliding_y = 0;
+	colliding_z = 0;
+
+	constructor(level: ClientLevel, id: string, width: number, height: number, eye_height: number) {
+		this.level = level;
+		this.id = id;
+		this.width = width;
+		this.height = height;
+		this.eye_height = eye_height;
+	}
+
+	get on_ground() {
+		return this.colliding_y === 1;
+	}
+
+	set_position(x: number, y: number, z: number) {
+		this.x = x;
+		this.y = y;
+		this.z = z;
+	}
+
+	abstract tick(delta: number): void;
+
+	// falls and moves by its velocity, stopping on each axis it would run into a block on
+	move(delta: number) {
+		this.vy += this.gravity * delta;
+
+		this.colliding_x = this.vx !== 0 && this.#collides(this.x + this.vx * delta, this.y, this.z)
+			? -Math.sign(this.vx)
+			: 0;
+		if (this.colliding_x !== 0) {
+			this.vx = 0;
+		}
+
+		this.colliding_y = this.vy !== 0 && this.#collides(this.x, this.y + this.vy * delta, this.z)
+			? -Math.sign(this.vy)
+			: 0;
+		if (this.colliding_y !== 0) {
+			this.vy = 0;
+		}
+
+		this.colliding_z = this.vz !== 0 && this.#collides(this.x, this.y, this.z + this.vz * delta)
+			? -Math.sign(this.vz)
+			: 0;
+		if (this.colliding_z !== 0) {
+			this.vz = 0;
+		}
+
+		this.x += this.vx * delta;
+		this.y += this.vy * delta;
+		this.z += this.vz * delta;
+	}
+
+	// whether the collision box at x/y/z overlaps any block, unloaded chunks included
+	#collides(x: number, y: number, z: number) {
+		const min_x = Math.floor(x - this.width / 2);
+		const max_x = Math.floor(x + this.width / 2);
+		const min_y = Math.floor(y);
+		const max_y = Math.floor(y + this.height);
+		const min_z = Math.floor(z - this.width / 2);
+		const max_z = Math.floor(z + this.width / 2);
+
+		for (let bx = min_x; bx <= max_x; bx++) {
+			for (let by = min_y; by <= max_y; by++) {
+				for (let bz = min_z; bz <= max_z; bz++) {
+					if (this.level.get_block(bx, by, bz)) {
+						return true;
+					}
+				}
+			}
+		}
+		return false;
+	}
+}