split the world update method into a separate step for clearer code w…

…hen using custom update logic.
melonjs · Aug 11, 2023 · 9e3de6a · 9e3de6a
1 parent fea7185
commit 9e3de6a
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Showing 3 changed files with 33 additions and 9 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,8 +5,12 @@
 ### Added
 - Input: new `hasActiveEvents` returning true if there are any pending events in the queue
 - Input: new `hasRegisteredEvents` returning true if there are registered pointer event listeners
+- Physic: new `WORLD_STEP` event emmitted after the builtin physic world has been updated (if enabled)
 - Renderer: fix/enable batching for all ellipse & arc(To) WebGL stroke operations
 
+### Changed
+- Physic: split the world update method into a separate step for clearer code when using custom update logic.
+
 ## [15.8.0] (melonJS 2) - _2023-07-29_
 
 ### Added

diff --git a/src/physics/world.js b/src/physics/world.js
@@ -164,11 +164,9 @@ export default class World extends Container {
     /**
      * update the game world
      * @param {number} dt - the time passed since the last frame update
-     * @returns {boolean} true if the word is dirty
+     * @returns {boolean} true if the world is dirty
      */
     update(dt) {
-        let isPaused = state.isPaused();
-
         // only update the quadtree if necessary
         if (this.physic === "builtin" || hasRegisteredEvents() === true) {
             // clear the quadtree
@@ -177,15 +175,26 @@ export default class World extends Container {
             this.broadphase.insertContainer(this);
         }
 
-        // only iterate through object is builtin physic is enabled
+        // update the builtin physic simulation
+        this.step(dt);
+
+        // call the super constructor
+        return super.update(dt);
+    }
+
+    /**
+     * update the builtin physic simulation by one step (called by the game world update method)
+     * @param {number} dt - the time passed since the last frame update
+     */
+    step(dt) {
         if (this.physic === "builtin") {
+            let isPaused = state.isPaused();
             // iterate through all bodies
             this.bodies.forEach((body) => {
                 if (!body.isStatic) {
                     let ancestor = body.ancestor;
                     // if the game is not paused, and ancestor can be updated
-                    if (!(isPaused && (!ancestor.updateWhenPaused)) &&
-                    (ancestor.inViewport || ancestor.alwaysUpdate)) {
+                    if (!(isPaused && (!ancestor.updateWhenPaused)) && (ancestor.inViewport || ancestor.alwaysUpdate)) {
                         // apply gravity to this body
                         this.bodyApplyGravity(body);
                         // body update function (this moves it)
@@ -201,9 +210,7 @@ export default class World extends Container {
                 }
             });
         }
-
-        // call the super constructor
-        return super.update(dt);
+        event.emit(event.WORLD_STEP, dt);
     }
 }
 
diff --git a/src/system/event.js b/src/system/event.js
@@ -230,6 +230,19 @@ export const GAME_BEFORE_DRAW = "me.game.beforeDraw";
  */
 export const GAME_AFTER_DRAW = "me.game.afterDraw";
 
+
+/**
+ * Event for when the physic world is updated
+ * Data passed : {number} time the current time stamp
+ * @public
+ * @constant
+ * @type {string}
+ * @name WORLD_STEP
+ * @memberof event
+ * @see event.on
+ */
+export const WORLD_STEP = "me.world.step";
+
 /**
  * Event for when a level is loaded <br>
  * Data passed : {string} Level Name