From 0f1d74582c070e0cde76cf10fff79daace10ec7a Mon Sep 17 00:00:00 2001
From: Tom Aisthorpe <tomaisthorpe@gmail.com>
Date: Mon, 15 Apr 2024 20:06:54 +0100
Subject: [PATCH] feat(physics): add 2d mode

---
 .changeset/popular-years-talk.md           |  5 +++++
 packages/ted/src/core/world.ts             |  3 +++
 packages/ted/src/index.ts                  |  1 +
 packages/ted/src/physics/rapier3d-world.ts | 22 ++++++++++++++++++++++
 4 files changed, 31 insertions(+)
 create mode 100644 .changeset/popular-years-talk.md

diff --git a/.changeset/popular-years-talk.md b/.changeset/popular-years-talk.md
new file mode 100644
index 0000000..bcfe862
--- /dev/null
+++ b/.changeset/popular-years-talk.md
@@ -0,0 +1,5 @@
+---
+"@tedengine/ted": minor
+---
+
+Add 2D physics mode
diff --git a/packages/ted/src/core/world.ts b/packages/ted/src/core/world.ts
index 4a2f82d..b6d5678 100644
--- a/packages/ted/src/core/world.ts
+++ b/packages/ted/src/core/world.ts
@@ -46,11 +46,14 @@ export interface TCollisionListener {
 }
 
 export interface TWorldConfig {
+  mode?: TPhysicsMode;
   gravity: vec3;
   defaultCollisionClass: string;
   collisionClasses: TCollisionClass[];
 }
 
+export type TPhysicsMode = '2d' | '3d';
+
 export interface TCollisionClass {
   name: string;
   ignores?: [string];
diff --git a/packages/ted/src/index.ts b/packages/ted/src/index.ts
index a95e7e3..31d25e5 100644
--- a/packages/ted/src/index.ts
+++ b/packages/ted/src/index.ts
@@ -39,6 +39,7 @@ export * from './core/game-state';
 
 export { default as TGameStateManager } from './core/game-state-manager';
 
+export * from './core/world';
 export { default as TWorld } from './core/world';
 export * from './core/messages';
 
diff --git a/packages/ted/src/physics/rapier3d-world.ts b/packages/ted/src/physics/rapier3d-world.ts
index 9b8d164..da44b9d 100644
--- a/packages/ted/src/physics/rapier3d-world.ts
+++ b/packages/ted/src/physics/rapier3d-world.ts
@@ -1,5 +1,6 @@
 import { vec3 } from 'gl-matrix';
 import type { TCollisionClass, TWorldConfig } from '../core/world';
+import { TPhysicsMode } from '../core/world';
 import type { TColliderConfig } from './colliders';
 import { TColliderType } from './colliders';
 import {
@@ -46,6 +47,8 @@ export default class TRapier3DWorld implements TPhysicsWorld {
     };
   } = {};
 
+  private physicsMode: TPhysicsMode = '3d';
+
   private objects: TRapierObject[] = [];
 
   public async create(config: TWorldConfig): Promise<void> {
@@ -62,6 +65,10 @@ export default class TRapier3DWorld implements TPhysicsWorld {
 
     this.setupCollisionClasses(config.collisionClasses);
     this.defaultCollisionClass = config.defaultCollisionClass;
+
+    if (config.mode) {
+      this.physicsMode = config.mode;
+    }
   }
 
   private setupCollisionClasses(collisionClasses: TCollisionClass[]) {
@@ -149,6 +156,15 @@ export default class TRapier3DWorld implements TPhysicsWorld {
     return { bodies, collisions };
   }
 
+  /**
+   * Adds a physics body to the world.
+   *
+   * @param uuid - The unique identifier for the body.
+   * @param collider - The configuration for the collider shape.
+   * @param translation - The initial translation of the body.
+   * @param rotation - The initial rotation of the body.
+   * @param options - Additional options for the body (optional).
+   */
   addBody(
     uuid: string,
     collider: TColliderConfig,
@@ -205,6 +221,12 @@ export default class TRapier3DWorld implements TPhysicsWorld {
       bodyDesc.lockRotations();
     }
 
+    // If we are in 2D mode, disable the Z axis, and only allow rotations around Z
+    if (this.physicsMode === '2d') {
+      bodyDesc.enabledTranslations(true, true, false);
+      bodyDesc.enabledRotations(false, false, true);
+    }
+
     bodyDesc.setTranslation(...translation);
     bodyDesc.setRotation({
       x: rotation[0],